diff options
author | Ben Cheng <bccheng@google.com> | 2014-03-25 22:37:19 -0700 |
---|---|---|
committer | Ben Cheng <bccheng@google.com> | 2014-03-25 22:37:19 -0700 |
commit | 1bc5aee63eb72b341f506ad058502cd0361f0d10 (patch) | |
tree | c607e8252f3405424ff15bc2d00aa38dadbb2518 /gcc-4.9/gcc/tree-vrp.c | |
parent | 283a0bf58fcf333c58a2a92c3ebbc41fb9eb1fdb (diff) | |
download | toolchain_gcc-1bc5aee63eb72b341f506ad058502cd0361f0d10.tar.gz toolchain_gcc-1bc5aee63eb72b341f506ad058502cd0361f0d10.tar.bz2 toolchain_gcc-1bc5aee63eb72b341f506ad058502cd0361f0d10.zip |
Initial checkin of GCC 4.9.0 from trunk (r208799).
Change-Id: I48a3c08bb98542aa215912a75f03c0890e497dba
Diffstat (limited to 'gcc-4.9/gcc/tree-vrp.c')
-rw-r--r-- | gcc-4.9/gcc/tree-vrp.c | 9915 |
1 files changed, 9915 insertions, 0 deletions
diff --git a/gcc-4.9/gcc/tree-vrp.c b/gcc-4.9/gcc/tree-vrp.c new file mode 100644 index 000000000..306021062 --- /dev/null +++ b/gcc-4.9/gcc/tree-vrp.c @@ -0,0 +1,9915 @@ +/* Support routines for Value Range Propagation (VRP). + Copyright (C) 2005-2014 Free Software Foundation, Inc. + Contributed by Diego Novillo <dnovillo@redhat.com>. + +This file is part of GCC. + +GCC is free software; you can redistribute it and/or modify +it under the terms of the GNU General Public License as published by +the Free Software Foundation; either version 3, or (at your option) +any later version. + +GCC is distributed in the hope that it will be useful, +but WITHOUT ANY WARRANTY; without even the implied warranty of +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +GNU General Public License for more details. + +You should have received a copy of the GNU General Public License +along with GCC; see the file COPYING3. If not see +<http://www.gnu.org/licenses/>. */ + +#include "config.h" +#include "system.h" +#include "coretypes.h" +#include "tm.h" +#include "flags.h" +#include "tree.h" +#include "stor-layout.h" +#include "calls.h" +#include "basic-block.h" +#include "tree-ssa-alias.h" +#include "internal-fn.h" +#include "gimple-fold.h" +#include "tree-eh.h" +#include "gimple-expr.h" +#include "is-a.h" +#include "gimple.h" +#include "gimple-iterator.h" +#include "gimple-walk.h" +#include "gimple-ssa.h" +#include "tree-cfg.h" +#include "tree-phinodes.h" +#include "ssa-iterators.h" +#include "stringpool.h" +#include "tree-ssanames.h" +#include "tree-ssa-loop-manip.h" +#include "tree-ssa-loop-niter.h" +#include "tree-ssa-loop.h" +#include "tree-into-ssa.h" +#include "tree-ssa.h" +#include "tree-pass.h" +#include "tree-dump.h" +#include "gimple-pretty-print.h" +#include "diagnostic-core.h" +#include "intl.h" +#include "cfgloop.h" +#include "tree-scalar-evolution.h" +#include "tree-ssa-propagate.h" +#include "tree-chrec.h" +#include "tree-ssa-threadupdate.h" +#include "expr.h" +#include "optabs.h" +#include "tree-ssa-threadedge.h" + + + +/* Range of values that can be associated with an SSA_NAME after VRP + has executed. */ +struct value_range_d +{ + /* Lattice value represented by this range. */ + enum value_range_type type; + + /* Minimum and maximum values represented by this range. These + values should be interpreted as follows: + + - If TYPE is VR_UNDEFINED or VR_VARYING then MIN and MAX must + be NULL. + + - If TYPE == VR_RANGE then MIN holds the minimum value and + MAX holds the maximum value of the range [MIN, MAX]. + + - If TYPE == ANTI_RANGE the variable is known to NOT + take any values in the range [MIN, MAX]. */ + tree min; + tree max; + + /* Set of SSA names whose value ranges are equivalent to this one. + This set is only valid when TYPE is VR_RANGE or VR_ANTI_RANGE. */ + bitmap equiv; +}; + +typedef struct value_range_d value_range_t; + +#define VR_INITIALIZER { VR_UNDEFINED, NULL_TREE, NULL_TREE, NULL } + +/* Set of SSA names found live during the RPO traversal of the function + for still active basic-blocks. */ +static sbitmap *live; + +/* Return true if the SSA name NAME is live on the edge E. */ + +static bool +live_on_edge (edge e, tree name) +{ + return (live[e->dest->index] + && bitmap_bit_p (live[e->dest->index], SSA_NAME_VERSION (name))); +} + +/* Local functions. */ +static int compare_values (tree val1, tree val2); +static int compare_values_warnv (tree val1, tree val2, bool *); +static void vrp_meet (value_range_t *, value_range_t *); +static void vrp_intersect_ranges (value_range_t *, value_range_t *); +static tree vrp_evaluate_conditional_warnv_with_ops (enum tree_code, + tree, tree, bool, bool *, + bool *); + +/* Location information for ASSERT_EXPRs. Each instance of this + structure describes an ASSERT_EXPR for an SSA name. Since a single + SSA name may have more than one assertion associated with it, these + locations are kept in a linked list attached to the corresponding + SSA name. */ +struct assert_locus_d +{ + /* Basic block where the assertion would be inserted. */ + basic_block bb; + + /* Some assertions need to be inserted on an edge (e.g., assertions + generated by COND_EXPRs). In those cases, BB will be NULL. */ + edge e; + + /* Pointer to the statement that generated this assertion. */ + gimple_stmt_iterator si; + + /* Predicate code for the ASSERT_EXPR. Must be COMPARISON_CLASS_P. */ + enum tree_code comp_code; + + /* Value being compared against. */ + tree val; + + /* Expression to compare. */ + tree expr; + + /* Next node in the linked list. */ + struct assert_locus_d *next; +}; + +typedef struct assert_locus_d *assert_locus_t; + +/* If bit I is present, it means that SSA name N_i has a list of + assertions that should be inserted in the IL. */ +static bitmap need_assert_for; + +/* Array of locations lists where to insert assertions. ASSERTS_FOR[I] + holds a list of ASSERT_LOCUS_T nodes that describe where + ASSERT_EXPRs for SSA name N_I should be inserted. */ +static assert_locus_t *asserts_for; + +/* Value range array. After propagation, VR_VALUE[I] holds the range + of values that SSA name N_I may take. */ +static unsigned num_vr_values; +static value_range_t **vr_value; +static bool values_propagated; + +/* For a PHI node which sets SSA name N_I, VR_COUNTS[I] holds the + number of executable edges we saw the last time we visited the + node. */ +static int *vr_phi_edge_counts; + +typedef struct { + gimple stmt; + tree vec; +} switch_update; + +static vec<edge> to_remove_edges; +static vec<switch_update> to_update_switch_stmts; + + +/* Return the maximum value for TYPE. */ + +static inline tree +vrp_val_max (const_tree type) +{ + if (!INTEGRAL_TYPE_P (type)) + return NULL_TREE; + + return TYPE_MAX_VALUE (type); +} + +/* Return the minimum value for TYPE. */ + +static inline tree +vrp_val_min (const_tree type) +{ + if (!INTEGRAL_TYPE_P (type)) + return NULL_TREE; + + return TYPE_MIN_VALUE (type); +} + +/* Return whether VAL is equal to the maximum value of its type. This + will be true for a positive overflow infinity. We can't do a + simple equality comparison with TYPE_MAX_VALUE because C typedefs + and Ada subtypes can produce types whose TYPE_MAX_VALUE is not == + to the integer constant with the same value in the type. */ + +static inline bool +vrp_val_is_max (const_tree val) +{ + tree type_max = vrp_val_max (TREE_TYPE (val)); + return (val == type_max + || (type_max != NULL_TREE + && operand_equal_p (val, type_max, 0))); +} + +/* Return whether VAL is equal to the minimum value of its type. This + will be true for a negative overflow infinity. */ + +static inline bool +vrp_val_is_min (const_tree val) +{ + tree type_min = vrp_val_min (TREE_TYPE (val)); + return (val == type_min + || (type_min != NULL_TREE + && operand_equal_p (val, type_min, 0))); +} + + +/* Return whether TYPE should use an overflow infinity distinct from + TYPE_{MIN,MAX}_VALUE. We use an overflow infinity value to + represent a signed overflow during VRP computations. An infinity + is distinct from a half-range, which will go from some number to + TYPE_{MIN,MAX}_VALUE. */ + +static inline bool +needs_overflow_infinity (const_tree type) +{ + return INTEGRAL_TYPE_P (type) && !TYPE_OVERFLOW_WRAPS (type); +} + +/* Return whether TYPE can support our overflow infinity + representation: we use the TREE_OVERFLOW flag, which only exists + for constants. If TYPE doesn't support this, we don't optimize + cases which would require signed overflow--we drop them to + VARYING. */ + +static inline bool +supports_overflow_infinity (const_tree type) +{ + tree min = vrp_val_min (type), max = vrp_val_max (type); +#ifdef ENABLE_CHECKING + gcc_assert (needs_overflow_infinity (type)); +#endif + return (min != NULL_TREE + && CONSTANT_CLASS_P (min) + && max != NULL_TREE + && CONSTANT_CLASS_P (max)); +} + +/* VAL is the maximum or minimum value of a type. Return a + corresponding overflow infinity. */ + +static inline tree +make_overflow_infinity (tree val) +{ + gcc_checking_assert (val != NULL_TREE && CONSTANT_CLASS_P (val)); + val = copy_node (val); + TREE_OVERFLOW (val) = 1; + return val; +} + +/* Return a negative overflow infinity for TYPE. */ + +static inline tree +negative_overflow_infinity (tree type) +{ + gcc_checking_assert (supports_overflow_infinity (type)); + return make_overflow_infinity (vrp_val_min (type)); +} + +/* Return a positive overflow infinity for TYPE. */ + +static inline tree +positive_overflow_infinity (tree type) +{ + gcc_checking_assert (supports_overflow_infinity (type)); + return make_overflow_infinity (vrp_val_max (type)); +} + +/* Return whether VAL is a negative overflow infinity. */ + +static inline bool +is_negative_overflow_infinity (const_tree val) +{ + return (needs_overflow_infinity (TREE_TYPE (val)) + && CONSTANT_CLASS_P (val) + && TREE_OVERFLOW (val) + && vrp_val_is_min (val)); +} + +/* Return whether VAL is a positive overflow infinity. */ + +static inline bool +is_positive_overflow_infinity (const_tree val) +{ + return (needs_overflow_infinity (TREE_TYPE (val)) + && CONSTANT_CLASS_P (val) + && TREE_OVERFLOW (val) + && vrp_val_is_max (val)); +} + +/* Return whether VAL is a positive or negative overflow infinity. */ + +static inline bool +is_overflow_infinity (const_tree val) +{ + return (needs_overflow_infinity (TREE_TYPE (val)) + && CONSTANT_CLASS_P (val) + && TREE_OVERFLOW (val) + && (vrp_val_is_min (val) || vrp_val_is_max (val))); +} + +/* Return whether STMT has a constant rhs that is_overflow_infinity. */ + +static inline bool +stmt_overflow_infinity (gimple stmt) +{ + if (is_gimple_assign (stmt) + && get_gimple_rhs_class (gimple_assign_rhs_code (stmt)) == + GIMPLE_SINGLE_RHS) + return is_overflow_infinity (gimple_assign_rhs1 (stmt)); + return false; +} + +/* If VAL is now an overflow infinity, return VAL. Otherwise, return + the same value with TREE_OVERFLOW clear. This can be used to avoid + confusing a regular value with an overflow value. */ + +static inline tree +avoid_overflow_infinity (tree val) +{ + if (!is_overflow_infinity (val)) + return val; + + if (vrp_val_is_max (val)) + return vrp_val_max (TREE_TYPE (val)); + else + { + gcc_checking_assert (vrp_val_is_min (val)); + return vrp_val_min (TREE_TYPE (val)); + } +} + + +/* Return true if ARG is marked with the nonnull attribute in the + current function signature. */ + +static bool +nonnull_arg_p (const_tree arg) +{ + tree t, attrs, fntype; + unsigned HOST_WIDE_INT arg_num; + + gcc_assert (TREE_CODE (arg) == PARM_DECL && POINTER_TYPE_P (TREE_TYPE (arg))); + + /* The static chain decl is always non null. */ + if (arg == cfun->static_chain_decl) + return true; + + fntype = TREE_TYPE (current_function_decl); + for (attrs = TYPE_ATTRIBUTES (fntype); attrs; attrs = TREE_CHAIN (attrs)) + { + attrs = lookup_attribute ("nonnull", attrs); + + /* If "nonnull" wasn't specified, we know nothing about the argument. */ + if (attrs == NULL_TREE) + return false; + + /* If "nonnull" applies to all the arguments, then ARG is non-null. */ + if (TREE_VALUE (attrs) == NULL_TREE) + return true; + + /* Get the position number for ARG in the function signature. */ + for (arg_num = 1, t = DECL_ARGUMENTS (current_function_decl); + t; + t = DECL_CHAIN (t), arg_num++) + { + if (t == arg) + break; + } + + gcc_assert (t == arg); + + /* Now see if ARG_NUM is mentioned in the nonnull list. */ + for (t = TREE_VALUE (attrs); t; t = TREE_CHAIN (t)) + { + if (compare_tree_int (TREE_VALUE (t), arg_num) == 0) + return true; + } + } + + return false; +} + + +/* Set value range VR to VR_UNDEFINED. */ + +static inline void +set_value_range_to_undefined (value_range_t *vr) +{ + vr->type = VR_UNDEFINED; + vr->min = vr->max = NULL_TREE; + if (vr->equiv) + bitmap_clear (vr->equiv); +} + + +/* Set value range VR to VR_VARYING. */ + +static inline void +set_value_range_to_varying (value_range_t *vr) +{ + vr->type = VR_VARYING; + vr->min = vr->max = NULL_TREE; + if (vr->equiv) + bitmap_clear (vr->equiv); +} + + +/* Set value range VR to {T, MIN, MAX, EQUIV}. */ + +static void +set_value_range (value_range_t *vr, enum value_range_type t, tree min, + tree max, bitmap equiv) +{ +#if defined ENABLE_CHECKING + /* Check the validity of the range. */ + if (t == VR_RANGE || t == VR_ANTI_RANGE) + { + int cmp; + + gcc_assert (min && max); + + gcc_assert ((!TREE_OVERFLOW_P (min) || is_overflow_infinity (min)) + && (!TREE_OVERFLOW_P (max) || is_overflow_infinity (max))); + + if (INTEGRAL_TYPE_P (TREE_TYPE (min)) && t == VR_ANTI_RANGE) + gcc_assert (!vrp_val_is_min (min) || !vrp_val_is_max (max)); + + cmp = compare_values (min, max); + gcc_assert (cmp == 0 || cmp == -1 || cmp == -2); + + if (needs_overflow_infinity (TREE_TYPE (min))) + gcc_assert (!is_overflow_infinity (min) + || !is_overflow_infinity (max)); + } + + if (t == VR_UNDEFINED || t == VR_VARYING) + gcc_assert (min == NULL_TREE && max == NULL_TREE); + + if (t == VR_UNDEFINED || t == VR_VARYING) + gcc_assert (equiv == NULL || bitmap_empty_p (equiv)); +#endif + + vr->type = t; + vr->min = min; + vr->max = max; + + /* Since updating the equivalence set involves deep copying the + bitmaps, only do it if absolutely necessary. */ + if (vr->equiv == NULL + && equiv != NULL) + vr->equiv = BITMAP_ALLOC (NULL); + + if (equiv != vr->equiv) + { + if (equiv && !bitmap_empty_p (equiv)) + bitmap_copy (vr->equiv, equiv); + else + bitmap_clear (vr->equiv); + } +} + + +/* Set value range VR to the canonical form of {T, MIN, MAX, EQUIV}. + This means adjusting T, MIN and MAX representing the case of a + wrapping range with MAX < MIN covering [MIN, type_max] U [type_min, MAX] + as anti-rage ~[MAX+1, MIN-1]. Likewise for wrapping anti-ranges. + In corner cases where MAX+1 or MIN-1 wraps this will fall back + to varying. + This routine exists to ease canonicalization in the case where we + extract ranges from var + CST op limit. */ + +static void +set_and_canonicalize_value_range (value_range_t *vr, enum value_range_type t, + tree min, tree max, bitmap equiv) +{ + /* Use the canonical setters for VR_UNDEFINED and VR_VARYING. */ + if (t == VR_UNDEFINED) + { + set_value_range_to_undefined (vr); + return; + } + else if (t == VR_VARYING) + { + set_value_range_to_varying (vr); + return; + } + + /* Nothing to canonicalize for symbolic ranges. */ + if (TREE_CODE (min) != INTEGER_CST + || TREE_CODE (max) != INTEGER_CST) + { + set_value_range (vr, t, min, max, equiv); + return; + } + + /* Wrong order for min and max, to swap them and the VR type we need + to adjust them. */ + if (tree_int_cst_lt (max, min)) + { + tree one, tmp; + + /* For one bit precision if max < min, then the swapped + range covers all values, so for VR_RANGE it is varying and + for VR_ANTI_RANGE empty range, so drop to varying as well. */ + if (TYPE_PRECISION (TREE_TYPE (min)) == 1) + { + set_value_range_to_varying (vr); + return; + } + + one = build_int_cst (TREE_TYPE (min), 1); + tmp = int_const_binop (PLUS_EXPR, max, one); + max = int_const_binop (MINUS_EXPR, min, one); + min = tmp; + + /* There's one corner case, if we had [C+1, C] before we now have + that again. But this represents an empty value range, so drop + to varying in this case. */ + if (tree_int_cst_lt (max, min)) + { + set_value_range_to_varying (vr); + return; + } + + t = t == VR_RANGE ? VR_ANTI_RANGE : VR_RANGE; + } + + /* Anti-ranges that can be represented as ranges should be so. */ + if (t == VR_ANTI_RANGE) + { + bool is_min = vrp_val_is_min (min); + bool is_max = vrp_val_is_max (max); + + if (is_min && is_max) + { + /* We cannot deal with empty ranges, drop to varying. + ??? This could be VR_UNDEFINED instead. */ + set_value_range_to_varying (vr); + return; + } + else if (TYPE_PRECISION (TREE_TYPE (min)) == 1 + && (is_min || is_max)) + { + /* Non-empty boolean ranges can always be represented + as a singleton range. */ + if (is_min) + min = max = vrp_val_max (TREE_TYPE (min)); + else + min = max = vrp_val_min (TREE_TYPE (min)); + t = VR_RANGE; + } + else if (is_min + /* As a special exception preserve non-null ranges. */ + && !(TYPE_UNSIGNED (TREE_TYPE (min)) + && integer_zerop (max))) + { + tree one = build_int_cst (TREE_TYPE (max), 1); + min = int_const_binop (PLUS_EXPR, max, one); + max = vrp_val_max (TREE_TYPE (max)); + t = VR_RANGE; + } + else if (is_max) + { + tree one = build_int_cst (TREE_TYPE (min), 1); + max = int_const_binop (MINUS_EXPR, min, one); + min = vrp_val_min (TREE_TYPE (min)); + t = VR_RANGE; + } + } + + /* Drop [-INF(OVF), +INF(OVF)] to varying. */ + if (needs_overflow_infinity (TREE_TYPE (min)) + && is_overflow_infinity (min) + && is_overflow_infinity (max)) + { + set_value_range_to_varying (vr); + return; + } + + set_value_range (vr, t, min, max, equiv); +} + +/* Copy value range FROM into value range TO. */ + +static inline void +copy_value_range (value_range_t *to, value_range_t *from) +{ + set_value_range (to, from->type, from->min, from->max, from->equiv); +} + +/* Set value range VR to a single value. This function is only called + with values we get from statements, and exists to clear the + TREE_OVERFLOW flag so that we don't think we have an overflow + infinity when we shouldn't. */ + +static inline void +set_value_range_to_value (value_range_t *vr, tree val, bitmap equiv) +{ + gcc_assert (is_gimple_min_invariant (val)); + if (TREE_OVERFLOW_P (val)) + val = drop_tree_overflow (val); + set_value_range (vr, VR_RANGE, val, val, equiv); +} + +/* Set value range VR to a non-negative range of type TYPE. + OVERFLOW_INFINITY indicates whether to use an overflow infinity + rather than TYPE_MAX_VALUE; this should be true if we determine + that the range is nonnegative based on the assumption that signed + overflow does not occur. */ + +static inline void +set_value_range_to_nonnegative (value_range_t *vr, tree type, + bool overflow_infinity) +{ + tree zero; + + if (overflow_infinity && !supports_overflow_infinity (type)) + { + set_value_range_to_varying (vr); + return; + } + + zero = build_int_cst (type, 0); + set_value_range (vr, VR_RANGE, zero, + (overflow_infinity + ? positive_overflow_infinity (type) + : TYPE_MAX_VALUE (type)), + vr->equiv); +} + +/* Set value range VR to a non-NULL range of type TYPE. */ + +static inline void +set_value_range_to_nonnull (value_range_t *vr, tree type) +{ + tree zero = build_int_cst (type, 0); + set_value_range (vr, VR_ANTI_RANGE, zero, zero, vr->equiv); +} + + +/* Set value range VR to a NULL range of type TYPE. */ + +static inline void +set_value_range_to_null (value_range_t *vr, tree type) +{ + set_value_range_to_value (vr, build_int_cst (type, 0), vr->equiv); +} + + +/* Set value range VR to a range of a truthvalue of type TYPE. */ + +static inline void +set_value_range_to_truthvalue (value_range_t *vr, tree type) +{ + if (TYPE_PRECISION (type) == 1) + set_value_range_to_varying (vr); + else + set_value_range (vr, VR_RANGE, + build_int_cst (type, 0), build_int_cst (type, 1), + vr->equiv); +} + + +/* If abs (min) < abs (max), set VR to [-max, max], if + abs (min) >= abs (max), set VR to [-min, min]. */ + +static void +abs_extent_range (value_range_t *vr, tree min, tree max) +{ + int cmp; + + gcc_assert (TREE_CODE (min) == INTEGER_CST); + gcc_assert (TREE_CODE (max) == INTEGER_CST); + gcc_assert (INTEGRAL_TYPE_P (TREE_TYPE (min))); + gcc_assert (!TYPE_UNSIGNED (TREE_TYPE (min))); + min = fold_unary (ABS_EXPR, TREE_TYPE (min), min); + max = fold_unary (ABS_EXPR, TREE_TYPE (max), max); + if (TREE_OVERFLOW (min) || TREE_OVERFLOW (max)) + { + set_value_range_to_varying (vr); + return; + } + cmp = compare_values (min, max); + if (cmp == -1) + min = fold_unary (NEGATE_EXPR, TREE_TYPE (min), max); + else if (cmp == 0 || cmp == 1) + { + max = min; + min = fold_unary (NEGATE_EXPR, TREE_TYPE (min), min); + } + else + { + set_value_range_to_varying (vr); + return; + } + set_and_canonicalize_value_range (vr, VR_RANGE, min, max, NULL); +} + + +/* Return value range information for VAR. + + If we have no values ranges recorded (ie, VRP is not running), then + return NULL. Otherwise create an empty range if none existed for VAR. */ + +static value_range_t * +get_value_range (const_tree var) +{ + static const struct value_range_d vr_const_varying + = { VR_VARYING, NULL_TREE, NULL_TREE, NULL }; + value_range_t *vr; + tree sym; + unsigned ver = SSA_NAME_VERSION (var); + + /* If we have no recorded ranges, then return NULL. */ + if (! vr_value) + return NULL; + + /* If we query the range for a new SSA name return an unmodifiable VARYING. + We should get here at most from the substitute-and-fold stage which + will never try to change values. */ + if (ver >= num_vr_values) + return CONST_CAST (value_range_t *, &vr_const_varying); + + vr = vr_value[ver]; + if (vr) + return vr; + + /* After propagation finished do not allocate new value-ranges. */ + if (values_propagated) + return CONST_CAST (value_range_t *, &vr_const_varying); + + /* Create a default value range. */ + vr_value[ver] = vr = XCNEW (value_range_t); + + /* Defer allocating the equivalence set. */ + vr->equiv = NULL; + + /* If VAR is a default definition of a parameter, the variable can + take any value in VAR's type. */ + if (SSA_NAME_IS_DEFAULT_DEF (var)) + { + sym = SSA_NAME_VAR (var); + if (TREE_CODE (sym) == PARM_DECL) + { + /* Try to use the "nonnull" attribute to create ~[0, 0] + anti-ranges for pointers. Note that this is only valid with + default definitions of PARM_DECLs. */ + if (POINTER_TYPE_P (TREE_TYPE (sym)) + && nonnull_arg_p (sym)) + set_value_range_to_nonnull (vr, TREE_TYPE (sym)); + else + set_value_range_to_varying (vr); + } + else if (TREE_CODE (sym) == RESULT_DECL + && DECL_BY_REFERENCE (sym)) + set_value_range_to_nonnull (vr, TREE_TYPE (sym)); + } + + return vr; +} + +/* Return true, if VAL1 and VAL2 are equal values for VRP purposes. */ + +static inline bool +vrp_operand_equal_p (const_tree val1, const_tree val2) +{ + if (val1 == val2) + return true; + if (!val1 || !val2 || !operand_equal_p (val1, val2, 0)) + return false; + if (is_overflow_infinity (val1)) + return is_overflow_infinity (val2); + return true; +} + +/* Return true, if the bitmaps B1 and B2 are equal. */ + +static inline bool +vrp_bitmap_equal_p (const_bitmap b1, const_bitmap b2) +{ + return (b1 == b2 + || ((!b1 || bitmap_empty_p (b1)) + && (!b2 || bitmap_empty_p (b2))) + || (b1 && b2 + && bitmap_equal_p (b1, b2))); +} + +/* Update the value range and equivalence set for variable VAR to + NEW_VR. Return true if NEW_VR is different from VAR's previous + value. + + NOTE: This function assumes that NEW_VR is a temporary value range + object created for the sole purpose of updating VAR's range. The + storage used by the equivalence set from NEW_VR will be freed by + this function. Do not call update_value_range when NEW_VR + is the range object associated with another SSA name. */ + +static inline bool +update_value_range (const_tree var, value_range_t *new_vr) +{ + value_range_t *old_vr; + bool is_new; + + /* Update the value range, if necessary. */ + old_vr = get_value_range (var); + is_new = old_vr->type != new_vr->type + || !vrp_operand_equal_p (old_vr->min, new_vr->min) + || !vrp_operand_equal_p (old_vr->max, new_vr->max) + || !vrp_bitmap_equal_p (old_vr->equiv, new_vr->equiv); + + if (is_new) + { + /* Do not allow transitions up the lattice. The following + is slightly more awkward than just new_vr->type < old_vr->type + because VR_RANGE and VR_ANTI_RANGE need to be considered + the same. We may not have is_new when transitioning to + UNDEFINED or from VARYING. */ + if (new_vr->type == VR_UNDEFINED + || old_vr->type == VR_VARYING) + set_value_range_to_varying (old_vr); + else + set_value_range (old_vr, new_vr->type, new_vr->min, new_vr->max, + new_vr->equiv); + } + + BITMAP_FREE (new_vr->equiv); + + return is_new; +} + + +/* Add VAR and VAR's equivalence set to EQUIV. This is the central + point where equivalence processing can be turned on/off. */ + +static void +add_equivalence (bitmap *equiv, const_tree var) +{ + unsigned ver = SSA_NAME_VERSION (var); + value_range_t *vr = vr_value[ver]; + + if (*equiv == NULL) + *equiv = BITMAP_ALLOC (NULL); + bitmap_set_bit (*equiv, ver); + if (vr && vr->equiv) + bitmap_ior_into (*equiv, vr->equiv); +} + + +/* Return true if VR is ~[0, 0]. */ + +static inline bool +range_is_nonnull (value_range_t *vr) +{ + return vr->type == VR_ANTI_RANGE + && integer_zerop (vr->min) + && integer_zerop (vr->max); +} + + +/* Return true if VR is [0, 0]. */ + +static inline bool +range_is_null (value_range_t *vr) +{ + return vr->type == VR_RANGE + && integer_zerop (vr->min) + && integer_zerop (vr->max); +} + +/* Return true if max and min of VR are INTEGER_CST. It's not necessary + a singleton. */ + +static inline bool +range_int_cst_p (value_range_t *vr) +{ + return (vr->type == VR_RANGE + && TREE_CODE (vr->max) == INTEGER_CST + && TREE_CODE (vr->min) == INTEGER_CST); +} + +/* Return true if VR is a INTEGER_CST singleton. */ + +static inline bool +range_int_cst_singleton_p (value_range_t *vr) +{ + return (range_int_cst_p (vr) + && !is_overflow_infinity (vr->min) + && !is_overflow_infinity (vr->max) + && tree_int_cst_equal (vr->min, vr->max)); +} + +/* Return true if value range VR involves at least one symbol. */ + +static inline bool +symbolic_range_p (value_range_t *vr) +{ + return (!is_gimple_min_invariant (vr->min) + || !is_gimple_min_invariant (vr->max)); +} + +/* Return true if value range VR uses an overflow infinity. */ + +static inline bool +overflow_infinity_range_p (value_range_t *vr) +{ + return (vr->type == VR_RANGE + && (is_overflow_infinity (vr->min) + || is_overflow_infinity (vr->max))); +} + +/* Return false if we can not make a valid comparison based on VR; + this will be the case if it uses an overflow infinity and overflow + is not undefined (i.e., -fno-strict-overflow is in effect). + Otherwise return true, and set *STRICT_OVERFLOW_P to true if VR + uses an overflow infinity. */ + +static bool +usable_range_p (value_range_t *vr, bool *strict_overflow_p) +{ + gcc_assert (vr->type == VR_RANGE); + if (is_overflow_infinity (vr->min)) + { + *strict_overflow_p = true; + if (!TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (vr->min))) + return false; + } + if (is_overflow_infinity (vr->max)) + { + *strict_overflow_p = true; + if (!TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (vr->max))) + return false; + } + return true; +} + + +/* Return true if the result of assignment STMT is know to be non-negative. + If the return value is based on the assumption that signed overflow is + undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't change + *STRICT_OVERFLOW_P.*/ + +static bool +gimple_assign_nonnegative_warnv_p (gimple stmt, bool *strict_overflow_p) +{ + enum tree_code code = gimple_assign_rhs_code (stmt); + switch (get_gimple_rhs_class (code)) + { + case GIMPLE_UNARY_RHS: + return tree_unary_nonnegative_warnv_p (gimple_assign_rhs_code (stmt), + gimple_expr_type (stmt), + gimple_assign_rhs1 (stmt), + strict_overflow_p); + case GIMPLE_BINARY_RHS: + return tree_binary_nonnegative_warnv_p (gimple_assign_rhs_code (stmt), + gimple_expr_type (stmt), + gimple_assign_rhs1 (stmt), + gimple_assign_rhs2 (stmt), + strict_overflow_p); + case GIMPLE_TERNARY_RHS: + return false; + case GIMPLE_SINGLE_RHS: + return tree_single_nonnegative_warnv_p (gimple_assign_rhs1 (stmt), + strict_overflow_p); + case GIMPLE_INVALID_RHS: + gcc_unreachable (); + default: + gcc_unreachable (); + } +} + +/* Return true if return value of call STMT is know to be non-negative. + If the return value is based on the assumption that signed overflow is + undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't change + *STRICT_OVERFLOW_P.*/ + +static bool +gimple_call_nonnegative_warnv_p (gimple stmt, bool *strict_overflow_p) +{ + tree arg0 = gimple_call_num_args (stmt) > 0 ? + gimple_call_arg (stmt, 0) : NULL_TREE; + tree arg1 = gimple_call_num_args (stmt) > 1 ? + gimple_call_arg (stmt, 1) : NULL_TREE; + + return tree_call_nonnegative_warnv_p (gimple_expr_type (stmt), + gimple_call_fndecl (stmt), + arg0, + arg1, + strict_overflow_p); +} + +/* Return true if STMT is know to to compute a non-negative value. + If the return value is based on the assumption that signed overflow is + undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't change + *STRICT_OVERFLOW_P.*/ + +static bool +gimple_stmt_nonnegative_warnv_p (gimple stmt, bool *strict_overflow_p) +{ + switch (gimple_code (stmt)) + { + case GIMPLE_ASSIGN: + return gimple_assign_nonnegative_warnv_p (stmt, strict_overflow_p); + case GIMPLE_CALL: + return gimple_call_nonnegative_warnv_p (stmt, strict_overflow_p); + default: + gcc_unreachable (); + } +} + +/* Return true if the result of assignment STMT is know to be non-zero. + If the return value is based on the assumption that signed overflow is + undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't change + *STRICT_OVERFLOW_P.*/ + +static bool +gimple_assign_nonzero_warnv_p (gimple stmt, bool *strict_overflow_p) +{ + enum tree_code code = gimple_assign_rhs_code (stmt); + switch (get_gimple_rhs_class (code)) + { + case GIMPLE_UNARY_RHS: + return tree_unary_nonzero_warnv_p (gimple_assign_rhs_code (stmt), + gimple_expr_type (stmt), + gimple_assign_rhs1 (stmt), + strict_overflow_p); + case GIMPLE_BINARY_RHS: + return tree_binary_nonzero_warnv_p (gimple_assign_rhs_code (stmt), + gimple_expr_type (stmt), + gimple_assign_rhs1 (stmt), + gimple_assign_rhs2 (stmt), + strict_overflow_p); + case GIMPLE_TERNARY_RHS: + return false; + case GIMPLE_SINGLE_RHS: + return tree_single_nonzero_warnv_p (gimple_assign_rhs1 (stmt), + strict_overflow_p); + case GIMPLE_INVALID_RHS: + gcc_unreachable (); + default: + gcc_unreachable (); + } +} + +/* Return true if STMT is known to compute a non-zero value. + If the return value is based on the assumption that signed overflow is + undefined, set *STRICT_OVERFLOW_P to true; otherwise, don't change + *STRICT_OVERFLOW_P.*/ + +static bool +gimple_stmt_nonzero_warnv_p (gimple stmt, bool *strict_overflow_p) +{ + switch (gimple_code (stmt)) + { + case GIMPLE_ASSIGN: + return gimple_assign_nonzero_warnv_p (stmt, strict_overflow_p); + case GIMPLE_CALL: + { + tree fndecl = gimple_call_fndecl (stmt); + if (!fndecl) return false; + if (flag_delete_null_pointer_checks && !flag_check_new + && DECL_IS_OPERATOR_NEW (fndecl) + && !TREE_NOTHROW (fndecl)) + return true; + if (flag_delete_null_pointer_checks && + lookup_attribute ("returns_nonnull", + TYPE_ATTRIBUTES (gimple_call_fntype (stmt)))) + return true; + return gimple_alloca_call_p (stmt); + } + default: + gcc_unreachable (); + } +} + +/* Like tree_expr_nonzero_warnv_p, but this function uses value ranges + obtained so far. */ + +static bool +vrp_stmt_computes_nonzero (gimple stmt, bool *strict_overflow_p) +{ + if (gimple_stmt_nonzero_warnv_p (stmt, strict_overflow_p)) + return true; + + /* If we have an expression of the form &X->a, then the expression + is nonnull if X is nonnull. */ + if (is_gimple_assign (stmt) + && gimple_assign_rhs_code (stmt) == ADDR_EXPR) + { + tree expr = gimple_assign_rhs1 (stmt); + tree base = get_base_address (TREE_OPERAND (expr, 0)); + + if (base != NULL_TREE + && TREE_CODE (base) == MEM_REF + && TREE_CODE (TREE_OPERAND (base, 0)) == SSA_NAME) + { + value_range_t *vr = get_value_range (TREE_OPERAND (base, 0)); + if (range_is_nonnull (vr)) + return true; + } + } + + return false; +} + +/* Returns true if EXPR is a valid value (as expected by compare_values) -- + a gimple invariant, or SSA_NAME +- CST. */ + +static bool +valid_value_p (tree expr) +{ + if (TREE_CODE (expr) == SSA_NAME) + return true; + + if (TREE_CODE (expr) == PLUS_EXPR + || TREE_CODE (expr) == MINUS_EXPR) + return (TREE_CODE (TREE_OPERAND (expr, 0)) == SSA_NAME + && TREE_CODE (TREE_OPERAND (expr, 1)) == INTEGER_CST); + + return is_gimple_min_invariant (expr); +} + +/* Return + 1 if VAL < VAL2 + 0 if !(VAL < VAL2) + -2 if those are incomparable. */ +static inline int +operand_less_p (tree val, tree val2) +{ + /* LT is folded faster than GE and others. Inline the common case. */ + if (TREE_CODE (val) == INTEGER_CST && TREE_CODE (val2) == INTEGER_CST) + { + if (TYPE_UNSIGNED (TREE_TYPE (val))) + return INT_CST_LT_UNSIGNED (val, val2); + else + { + if (INT_CST_LT (val, val2)) + return 1; + } + } + else + { + tree tcmp; + + fold_defer_overflow_warnings (); + + tcmp = fold_binary_to_constant (LT_EXPR, boolean_type_node, val, val2); + + fold_undefer_and_ignore_overflow_warnings (); + + if (!tcmp + || TREE_CODE (tcmp) != INTEGER_CST) + return -2; + + if (!integer_zerop (tcmp)) + return 1; + } + + /* val >= val2, not considering overflow infinity. */ + if (is_negative_overflow_infinity (val)) + return is_negative_overflow_infinity (val2) ? 0 : 1; + else if (is_positive_overflow_infinity (val2)) + return is_positive_overflow_infinity (val) ? 0 : 1; + + return 0; +} + +/* Compare two values VAL1 and VAL2. Return + + -2 if VAL1 and VAL2 cannot be compared at compile-time, + -1 if VAL1 < VAL2, + 0 if VAL1 == VAL2, + +1 if VAL1 > VAL2, and + +2 if VAL1 != VAL2 + + This is similar to tree_int_cst_compare but supports pointer values + and values that cannot be compared at compile time. + + If STRICT_OVERFLOW_P is not NULL, then set *STRICT_OVERFLOW_P to + true if the return value is only valid if we assume that signed + overflow is undefined. */ + +static int +compare_values_warnv (tree val1, tree val2, bool *strict_overflow_p) +{ + if (val1 == val2) + return 0; + + /* Below we rely on the fact that VAL1 and VAL2 are both pointers or + both integers. */ + gcc_assert (POINTER_TYPE_P (TREE_TYPE (val1)) + == POINTER_TYPE_P (TREE_TYPE (val2))); + /* Convert the two values into the same type. This is needed because + sizetype causes sign extension even for unsigned types. */ + val2 = fold_convert (TREE_TYPE (val1), val2); + STRIP_USELESS_TYPE_CONVERSION (val2); + + if ((TREE_CODE (val1) == SSA_NAME + || TREE_CODE (val1) == PLUS_EXPR + || TREE_CODE (val1) == MINUS_EXPR) + && (TREE_CODE (val2) == SSA_NAME + || TREE_CODE (val2) == PLUS_EXPR + || TREE_CODE (val2) == MINUS_EXPR)) + { + tree n1, c1, n2, c2; + enum tree_code code1, code2; + + /* If VAL1 and VAL2 are of the form 'NAME [+-] CST' or 'NAME', + return -1 or +1 accordingly. If VAL1 and VAL2 don't use the + same name, return -2. */ + if (TREE_CODE (val1) == SSA_NAME) + { + code1 = SSA_NAME; + n1 = val1; + c1 = NULL_TREE; + } + else + { + code1 = TREE_CODE (val1); + n1 = TREE_OPERAND (val1, 0); + c1 = TREE_OPERAND (val1, 1); + if (tree_int_cst_sgn (c1) == -1) + { + if (is_negative_overflow_infinity (c1)) + return -2; + c1 = fold_unary_to_constant (NEGATE_EXPR, TREE_TYPE (c1), c1); + if (!c1) + return -2; + code1 = code1 == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR; + } + } + + if (TREE_CODE (val2) == SSA_NAME) + { + code2 = SSA_NAME; + n2 = val2; + c2 = NULL_TREE; + } + else + { + code2 = TREE_CODE (val2); + n2 = TREE_OPERAND (val2, 0); + c2 = TREE_OPERAND (val2, 1); + if (tree_int_cst_sgn (c2) == -1) + { + if (is_negative_overflow_infinity (c2)) + return -2; + c2 = fold_unary_to_constant (NEGATE_EXPR, TREE_TYPE (c2), c2); + if (!c2) + return -2; + code2 = code2 == MINUS_EXPR ? PLUS_EXPR : MINUS_EXPR; + } + } + + /* Both values must use the same name. */ + if (n1 != n2) + return -2; + + if (code1 == SSA_NAME + && code2 == SSA_NAME) + /* NAME == NAME */ + return 0; + + /* If overflow is defined we cannot simplify more. */ + if (!TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (val1))) + return -2; + + if (strict_overflow_p != NULL + && (code1 == SSA_NAME || !TREE_NO_WARNING (val1)) + && (code2 == SSA_NAME || !TREE_NO_WARNING (val2))) + *strict_overflow_p = true; + + if (code1 == SSA_NAME) + { + if (code2 == PLUS_EXPR) + /* NAME < NAME + CST */ + return -1; + else if (code2 == MINUS_EXPR) + /* NAME > NAME - CST */ + return 1; + } + else if (code1 == PLUS_EXPR) + { + if (code2 == SSA_NAME) + /* NAME + CST > NAME */ + return 1; + else if (code2 == PLUS_EXPR) + /* NAME + CST1 > NAME + CST2, if CST1 > CST2 */ + return compare_values_warnv (c1, c2, strict_overflow_p); + else if (code2 == MINUS_EXPR) + /* NAME + CST1 > NAME - CST2 */ + return 1; + } + else if (code1 == MINUS_EXPR) + { + if (code2 == SSA_NAME) + /* NAME - CST < NAME */ + return -1; + else if (code2 == PLUS_EXPR) + /* NAME - CST1 < NAME + CST2 */ + return -1; + else if (code2 == MINUS_EXPR) + /* NAME - CST1 > NAME - CST2, if CST1 < CST2. Notice that + C1 and C2 are swapped in the call to compare_values. */ + return compare_values_warnv (c2, c1, strict_overflow_p); + } + + gcc_unreachable (); + } + + /* We cannot compare non-constants. */ + if (!is_gimple_min_invariant (val1) || !is_gimple_min_invariant (val2)) + return -2; + + if (!POINTER_TYPE_P (TREE_TYPE (val1))) + { + /* We cannot compare overflowed values, except for overflow + infinities. */ + if (TREE_OVERFLOW (val1) || TREE_OVERFLOW (val2)) + { + if (strict_overflow_p != NULL) + *strict_overflow_p = true; + if (is_negative_overflow_infinity (val1)) + return is_negative_overflow_infinity (val2) ? 0 : -1; + else if (is_negative_overflow_infinity (val2)) + return 1; + else if (is_positive_overflow_infinity (val1)) + return is_positive_overflow_infinity (val2) ? 0 : 1; + else if (is_positive_overflow_infinity (val2)) + return -1; + return -2; + } + + return tree_int_cst_compare (val1, val2); + } + else + { + tree t; + + /* First see if VAL1 and VAL2 are not the same. */ + if (val1 == val2 || operand_equal_p (val1, val2, 0)) + return 0; + + /* If VAL1 is a lower address than VAL2, return -1. */ + if (operand_less_p (val1, val2) == 1) + return -1; + + /* If VAL1 is a higher address than VAL2, return +1. */ + if (operand_less_p (val2, val1) == 1) + return 1; + + /* If VAL1 is different than VAL2, return +2. + For integer constants we either have already returned -1 or 1 + or they are equivalent. We still might succeed in proving + something about non-trivial operands. */ + if (TREE_CODE (val1) != INTEGER_CST + || TREE_CODE (val2) != INTEGER_CST) + { + t = fold_binary_to_constant (NE_EXPR, boolean_type_node, val1, val2); + if (t && integer_onep (t)) + return 2; + } + + return -2; + } +} + +/* Compare values like compare_values_warnv, but treat comparisons of + nonconstants which rely on undefined overflow as incomparable. */ + +static int +compare_values (tree val1, tree val2) +{ + bool sop; + int ret; + + sop = false; + ret = compare_values_warnv (val1, val2, &sop); + if (sop + && (!is_gimple_min_invariant (val1) || !is_gimple_min_invariant (val2))) + ret = -2; + return ret; +} + + +/* Return 1 if VAL is inside value range MIN <= VAL <= MAX, + 0 if VAL is not inside [MIN, MAX], + -2 if we cannot tell either way. + + Benchmark compile/20001226-1.c compilation time after changing this + function. */ + +static inline int +value_inside_range (tree val, tree min, tree max) +{ + int cmp1, cmp2; + + cmp1 = operand_less_p (val, min); + if (cmp1 == -2) + return -2; + if (cmp1 == 1) + return 0; + + cmp2 = operand_less_p (max, val); + if (cmp2 == -2) + return -2; + + return !cmp2; +} + + +/* Return true if value ranges VR0 and VR1 have a non-empty + intersection. + + Benchmark compile/20001226-1.c compilation time after changing this + function. + */ + +static inline bool +value_ranges_intersect_p (value_range_t *vr0, value_range_t *vr1) +{ + /* The value ranges do not intersect if the maximum of the first range is + less than the minimum of the second range or vice versa. + When those relations are unknown, we can't do any better. */ + if (operand_less_p (vr0->max, vr1->min) != 0) + return false; + if (operand_less_p (vr1->max, vr0->min) != 0) + return false; + return true; +} + + +/* Return 1 if [MIN, MAX] includes the value zero, 0 if it does not + include the value zero, -2 if we cannot tell. */ + +static inline int +range_includes_zero_p (tree min, tree max) +{ + tree zero = build_int_cst (TREE_TYPE (min), 0); + return value_inside_range (zero, min, max); +} + +/* Return true if *VR is know to only contain nonnegative values. */ + +static inline bool +value_range_nonnegative_p (value_range_t *vr) +{ + /* Testing for VR_ANTI_RANGE is not useful here as any anti-range + which would return a useful value should be encoded as a + VR_RANGE. */ + if (vr->type == VR_RANGE) + { + int result = compare_values (vr->min, integer_zero_node); + return (result == 0 || result == 1); + } + + return false; +} + +/* If *VR has a value rante that is a single constant value return that, + otherwise return NULL_TREE. */ + +static tree +value_range_constant_singleton (value_range_t *vr) +{ + if (vr->type == VR_RANGE + && operand_equal_p (vr->min, vr->max, 0) + && is_gimple_min_invariant (vr->min)) + return vr->min; + + return NULL_TREE; +} + +/* If OP has a value range with a single constant value return that, + otherwise return NULL_TREE. This returns OP itself if OP is a + constant. */ + +static tree +op_with_constant_singleton_value_range (tree op) +{ + if (is_gimple_min_invariant (op)) + return op; + + if (TREE_CODE (op) != SSA_NAME) + return NULL_TREE; + + return value_range_constant_singleton (get_value_range (op)); +} + +/* Return true if op is in a boolean [0, 1] value-range. */ + +static bool +op_with_boolean_value_range_p (tree op) +{ + value_range_t *vr; + + if (TYPE_PRECISION (TREE_TYPE (op)) == 1) + return true; + + if (integer_zerop (op) + || integer_onep (op)) + return true; + + if (TREE_CODE (op) != SSA_NAME) + return false; + + vr = get_value_range (op); + return (vr->type == VR_RANGE + && integer_zerop (vr->min) + && integer_onep (vr->max)); +} + +/* Extract value range information from an ASSERT_EXPR EXPR and store + it in *VR_P. */ + +static void +extract_range_from_assert (value_range_t *vr_p, tree expr) +{ + tree var, cond, limit, min, max, type; + value_range_t *limit_vr; + enum tree_code cond_code; + + var = ASSERT_EXPR_VAR (expr); + cond = ASSERT_EXPR_COND (expr); + + gcc_assert (COMPARISON_CLASS_P (cond)); + + /* Find VAR in the ASSERT_EXPR conditional. */ + if (var == TREE_OPERAND (cond, 0) + || TREE_CODE (TREE_OPERAND (cond, 0)) == PLUS_EXPR + || TREE_CODE (TREE_OPERAND (cond, 0)) == NOP_EXPR) + { + /* If the predicate is of the form VAR COMP LIMIT, then we just + take LIMIT from the RHS and use the same comparison code. */ + cond_code = TREE_CODE (cond); + limit = TREE_OPERAND (cond, 1); + cond = TREE_OPERAND (cond, 0); + } + else + { + /* If the predicate is of the form LIMIT COMP VAR, then we need + to flip around the comparison code to create the proper range + for VAR. */ + cond_code = swap_tree_comparison (TREE_CODE (cond)); + limit = TREE_OPERAND (cond, 0); + cond = TREE_OPERAND (cond, 1); + } + + limit = avoid_overflow_infinity (limit); + + type = TREE_TYPE (var); + gcc_assert (limit != var); + + /* For pointer arithmetic, we only keep track of pointer equality + and inequality. */ + if (POINTER_TYPE_P (type) && cond_code != NE_EXPR && cond_code != EQ_EXPR) + { + set_value_range_to_varying (vr_p); + return; + } + + /* If LIMIT is another SSA name and LIMIT has a range of its own, + try to use LIMIT's range to avoid creating symbolic ranges + unnecessarily. */ + limit_vr = (TREE_CODE (limit) == SSA_NAME) ? get_value_range (limit) : NULL; + + /* LIMIT's range is only interesting if it has any useful information. */ + if (limit_vr + && (limit_vr->type == VR_UNDEFINED + || limit_vr->type == VR_VARYING + || symbolic_range_p (limit_vr))) + limit_vr = NULL; + + /* Initially, the new range has the same set of equivalences of + VAR's range. This will be revised before returning the final + value. Since assertions may be chained via mutually exclusive + predicates, we will need to trim the set of equivalences before + we are done. */ + gcc_assert (vr_p->equiv == NULL); + add_equivalence (&vr_p->equiv, var); + + /* Extract a new range based on the asserted comparison for VAR and + LIMIT's value range. Notice that if LIMIT has an anti-range, we + will only use it for equality comparisons (EQ_EXPR). For any + other kind of assertion, we cannot derive a range from LIMIT's + anti-range that can be used to describe the new range. For + instance, ASSERT_EXPR <x_2, x_2 <= b_4>. If b_4 is ~[2, 10], + then b_4 takes on the ranges [-INF, 1] and [11, +INF]. There is + no single range for x_2 that could describe LE_EXPR, so we might + as well build the range [b_4, +INF] for it. + One special case we handle is extracting a range from a + range test encoded as (unsigned)var + CST <= limit. */ + if (TREE_CODE (cond) == NOP_EXPR + || TREE_CODE (cond) == PLUS_EXPR) + { + if (TREE_CODE (cond) == PLUS_EXPR) + { + min = fold_build1 (NEGATE_EXPR, TREE_TYPE (TREE_OPERAND (cond, 1)), + TREE_OPERAND (cond, 1)); + max = int_const_binop (PLUS_EXPR, limit, min); + cond = TREE_OPERAND (cond, 0); + } + else + { + min = build_int_cst (TREE_TYPE (var), 0); + max = limit; + } + + /* Make sure to not set TREE_OVERFLOW on the final type + conversion. We are willingly interpreting large positive + unsigned values as negative singed values here. */ + min = force_fit_type_double (TREE_TYPE (var), tree_to_double_int (min), + 0, false); + max = force_fit_type_double (TREE_TYPE (var), tree_to_double_int (max), + 0, false); + + /* We can transform a max, min range to an anti-range or + vice-versa. Use set_and_canonicalize_value_range which does + this for us. */ + if (cond_code == LE_EXPR) + set_and_canonicalize_value_range (vr_p, VR_RANGE, + min, max, vr_p->equiv); + else if (cond_code == GT_EXPR) + set_and_canonicalize_value_range (vr_p, VR_ANTI_RANGE, + min, max, vr_p->equiv); + else + gcc_unreachable (); + } + else if (cond_code == EQ_EXPR) + { + enum value_range_type range_type; + + if (limit_vr) + { + range_type = limit_vr->type; + min = limit_vr->min; + max = limit_vr->max; + } + else + { + range_type = VR_RANGE; + min = limit; + max = limit; + } + + set_value_range (vr_p, range_type, min, max, vr_p->equiv); + + /* When asserting the equality VAR == LIMIT and LIMIT is another + SSA name, the new range will also inherit the equivalence set + from LIMIT. */ + if (TREE_CODE (limit) == SSA_NAME) + add_equivalence (&vr_p->equiv, limit); + } + else if (cond_code == NE_EXPR) + { + /* As described above, when LIMIT's range is an anti-range and + this assertion is an inequality (NE_EXPR), then we cannot + derive anything from the anti-range. For instance, if + LIMIT's range was ~[0, 0], the assertion 'VAR != LIMIT' does + not imply that VAR's range is [0, 0]. So, in the case of + anti-ranges, we just assert the inequality using LIMIT and + not its anti-range. + + If LIMIT_VR is a range, we can only use it to build a new + anti-range if LIMIT_VR is a single-valued range. For + instance, if LIMIT_VR is [0, 1], the predicate + VAR != [0, 1] does not mean that VAR's range is ~[0, 1]. + Rather, it means that for value 0 VAR should be ~[0, 0] + and for value 1, VAR should be ~[1, 1]. We cannot + represent these ranges. + + The only situation in which we can build a valid + anti-range is when LIMIT_VR is a single-valued range + (i.e., LIMIT_VR->MIN == LIMIT_VR->MAX). In that case, + build the anti-range ~[LIMIT_VR->MIN, LIMIT_VR->MAX]. */ + if (limit_vr + && limit_vr->type == VR_RANGE + && compare_values (limit_vr->min, limit_vr->max) == 0) + { + min = limit_vr->min; + max = limit_vr->max; + } + else + { + /* In any other case, we cannot use LIMIT's range to build a + valid anti-range. */ + min = max = limit; + } + + /* If MIN and MAX cover the whole range for their type, then + just use the original LIMIT. */ + if (INTEGRAL_TYPE_P (type) + && vrp_val_is_min (min) + && vrp_val_is_max (max)) + min = max = limit; + + set_and_canonicalize_value_range (vr_p, VR_ANTI_RANGE, + min, max, vr_p->equiv); + } + else if (cond_code == LE_EXPR || cond_code == LT_EXPR) + { + min = TYPE_MIN_VALUE (type); + + if (limit_vr == NULL || limit_vr->type == VR_ANTI_RANGE) + max = limit; + else + { + /* If LIMIT_VR is of the form [N1, N2], we need to build the + range [MIN, N2] for LE_EXPR and [MIN, N2 - 1] for + LT_EXPR. */ + max = limit_vr->max; + } + + /* If the maximum value forces us to be out of bounds, simply punt. + It would be pointless to try and do anything more since this + all should be optimized away above us. */ + if ((cond_code == LT_EXPR + && compare_values (max, min) == 0) + || is_overflow_infinity (max)) + set_value_range_to_varying (vr_p); + else + { + /* For LT_EXPR, we create the range [MIN, MAX - 1]. */ + if (cond_code == LT_EXPR) + { + if (TYPE_PRECISION (TREE_TYPE (max)) == 1 + && !TYPE_UNSIGNED (TREE_TYPE (max))) + max = fold_build2 (PLUS_EXPR, TREE_TYPE (max), max, + build_int_cst (TREE_TYPE (max), -1)); + else + max = fold_build2 (MINUS_EXPR, TREE_TYPE (max), max, + build_int_cst (TREE_TYPE (max), 1)); + if (EXPR_P (max)) + TREE_NO_WARNING (max) = 1; + } + + set_value_range (vr_p, VR_RANGE, min, max, vr_p->equiv); + } + } + else if (cond_code == GE_EXPR || cond_code == GT_EXPR) + { + max = TYPE_MAX_VALUE (type); + + if (limit_vr == NULL || limit_vr->type == VR_ANTI_RANGE) + min = limit; + else + { + /* If LIMIT_VR is of the form [N1, N2], we need to build the + range [N1, MAX] for GE_EXPR and [N1 + 1, MAX] for + GT_EXPR. */ + min = limit_vr->min; + } + + /* If the minimum value forces us to be out of bounds, simply punt. + It would be pointless to try and do anything more since this + all should be optimized away above us. */ + if ((cond_code == GT_EXPR + && compare_values (min, max) == 0) + || is_overflow_infinity (min)) + set_value_range_to_varying (vr_p); + else + { + /* For GT_EXPR, we create the range [MIN + 1, MAX]. */ + if (cond_code == GT_EXPR) + { + if (TYPE_PRECISION (TREE_TYPE (min)) == 1 + && !TYPE_UNSIGNED (TREE_TYPE (min))) + min = fold_build2 (MINUS_EXPR, TREE_TYPE (min), min, + build_int_cst (TREE_TYPE (min), -1)); + else + min = fold_build2 (PLUS_EXPR, TREE_TYPE (min), min, + build_int_cst (TREE_TYPE (min), 1)); + if (EXPR_P (min)) + TREE_NO_WARNING (min) = 1; + } + + set_value_range (vr_p, VR_RANGE, min, max, vr_p->equiv); + } + } + else + gcc_unreachable (); + + /* Finally intersect the new range with what we already know about var. */ + vrp_intersect_ranges (vr_p, get_value_range (var)); +} + + +/* Extract range information from SSA name VAR and store it in VR. If + VAR has an interesting range, use it. Otherwise, create the + range [VAR, VAR] and return it. This is useful in situations where + we may have conditionals testing values of VARYING names. For + instance, + + x_3 = y_5; + if (x_3 > y_5) + ... + + Even if y_5 is deemed VARYING, we can determine that x_3 > y_5 is + always false. */ + +static void +extract_range_from_ssa_name (value_range_t *vr, tree var) +{ + value_range_t *var_vr = get_value_range (var); + + if (var_vr->type != VR_UNDEFINED && var_vr->type != VR_VARYING) + copy_value_range (vr, var_vr); + else + set_value_range (vr, VR_RANGE, var, var, NULL); + + add_equivalence (&vr->equiv, var); +} + + +/* Wrapper around int_const_binop. If the operation overflows and we + are not using wrapping arithmetic, then adjust the result to be + -INF or +INF depending on CODE, VAL1 and VAL2. This can return + NULL_TREE if we need to use an overflow infinity representation but + the type does not support it. */ + +static tree +vrp_int_const_binop (enum tree_code code, tree val1, tree val2) +{ + tree res; + + res = int_const_binop (code, val1, val2); + + /* If we are using unsigned arithmetic, operate symbolically + on -INF and +INF as int_const_binop only handles signed overflow. */ + if (TYPE_UNSIGNED (TREE_TYPE (val1))) + { + int checkz = compare_values (res, val1); + bool overflow = false; + + /* Ensure that res = val1 [+*] val2 >= val1 + or that res = val1 - val2 <= val1. */ + if ((code == PLUS_EXPR + && !(checkz == 1 || checkz == 0)) + || (code == MINUS_EXPR + && !(checkz == 0 || checkz == -1))) + { + overflow = true; + } + /* Checking for multiplication overflow is done by dividing the + output of the multiplication by the first input of the + multiplication. If the result of that division operation is + not equal to the second input of the multiplication, then the + multiplication overflowed. */ + else if (code == MULT_EXPR && !integer_zerop (val1)) + { + tree tmp = int_const_binop (TRUNC_DIV_EXPR, + res, + val1); + int check = compare_values (tmp, val2); + + if (check != 0) + overflow = true; + } + + if (overflow) + { + res = copy_node (res); + TREE_OVERFLOW (res) = 1; + } + + } + else if (TYPE_OVERFLOW_WRAPS (TREE_TYPE (val1))) + /* If the singed operation wraps then int_const_binop has done + everything we want. */ + ; + else if ((TREE_OVERFLOW (res) + && !TREE_OVERFLOW (val1) + && !TREE_OVERFLOW (val2)) + || is_overflow_infinity (val1) + || is_overflow_infinity (val2)) + { + /* If the operation overflowed but neither VAL1 nor VAL2 are + overflown, return -INF or +INF depending on the operation + and the combination of signs of the operands. */ + int sgn1 = tree_int_cst_sgn (val1); + int sgn2 = tree_int_cst_sgn (val2); + + if (needs_overflow_infinity (TREE_TYPE (res)) + && !supports_overflow_infinity (TREE_TYPE (res))) + return NULL_TREE; + + /* We have to punt on adding infinities of different signs, + since we can't tell what the sign of the result should be. + Likewise for subtracting infinities of the same sign. */ + if (((code == PLUS_EXPR && sgn1 != sgn2) + || (code == MINUS_EXPR && sgn1 == sgn2)) + && is_overflow_infinity (val1) + && is_overflow_infinity (val2)) + return NULL_TREE; + + /* Don't try to handle division or shifting of infinities. */ + if ((code == TRUNC_DIV_EXPR + || code == FLOOR_DIV_EXPR + || code == CEIL_DIV_EXPR + || code == EXACT_DIV_EXPR + || code == ROUND_DIV_EXPR + || code == RSHIFT_EXPR) + && (is_overflow_infinity (val1) + || is_overflow_infinity (val2))) + return NULL_TREE; + + /* Notice that we only need to handle the restricted set of + operations handled by extract_range_from_binary_expr. + Among them, only multiplication, addition and subtraction + can yield overflow without overflown operands because we + are working with integral types only... except in the + case VAL1 = -INF and VAL2 = -1 which overflows to +INF + for division too. */ + + /* For multiplication, the sign of the overflow is given + by the comparison of the signs of the operands. */ + if ((code == MULT_EXPR && sgn1 == sgn2) + /* For addition, the operands must be of the same sign + to yield an overflow. Its sign is therefore that + of one of the operands, for example the first. For + infinite operands X + -INF is negative, not positive. */ + || (code == PLUS_EXPR + && (sgn1 >= 0 + ? !is_negative_overflow_infinity (val2) + : is_positive_overflow_infinity (val2))) + /* For subtraction, non-infinite operands must be of + different signs to yield an overflow. Its sign is + therefore that of the first operand or the opposite of + that of the second operand. A first operand of 0 counts + as positive here, for the corner case 0 - (-INF), which + overflows, but must yield +INF. For infinite operands 0 + - INF is negative, not positive. */ + || (code == MINUS_EXPR + && (sgn1 >= 0 + ? !is_positive_overflow_infinity (val2) + : is_negative_overflow_infinity (val2))) + /* We only get in here with positive shift count, so the + overflow direction is the same as the sign of val1. + Actually rshift does not overflow at all, but we only + handle the case of shifting overflowed -INF and +INF. */ + || (code == RSHIFT_EXPR + && sgn1 >= 0) + /* For division, the only case is -INF / -1 = +INF. */ + || code == TRUNC_DIV_EXPR + || code == FLOOR_DIV_EXPR + || code == CEIL_DIV_EXPR + || code == EXACT_DIV_EXPR + || code == ROUND_DIV_EXPR) + return (needs_overflow_infinity (TREE_TYPE (res)) + ? positive_overflow_infinity (TREE_TYPE (res)) + : TYPE_MAX_VALUE (TREE_TYPE (res))); + else + return (needs_overflow_infinity (TREE_TYPE (res)) + ? negative_overflow_infinity (TREE_TYPE (res)) + : TYPE_MIN_VALUE (TREE_TYPE (res))); + } + + return res; +} + + +/* For range VR compute two double_int bitmasks. In *MAY_BE_NONZERO + bitmask if some bit is unset, it means for all numbers in the range + the bit is 0, otherwise it might be 0 or 1. In *MUST_BE_NONZERO + bitmask if some bit is set, it means for all numbers in the range + the bit is 1, otherwise it might be 0 or 1. */ + +static bool +zero_nonzero_bits_from_vr (value_range_t *vr, + double_int *may_be_nonzero, + double_int *must_be_nonzero) +{ + *may_be_nonzero = double_int_minus_one; + *must_be_nonzero = double_int_zero; + if (!range_int_cst_p (vr) + || is_overflow_infinity (vr->min) + || is_overflow_infinity (vr->max)) + return false; + + if (range_int_cst_singleton_p (vr)) + { + *may_be_nonzero = tree_to_double_int (vr->min); + *must_be_nonzero = *may_be_nonzero; + } + else if (tree_int_cst_sgn (vr->min) >= 0 + || tree_int_cst_sgn (vr->max) < 0) + { + double_int dmin = tree_to_double_int (vr->min); + double_int dmax = tree_to_double_int (vr->max); + double_int xor_mask = dmin ^ dmax; + *may_be_nonzero = dmin | dmax; + *must_be_nonzero = dmin & dmax; + if (xor_mask.high != 0) + { + unsigned HOST_WIDE_INT mask + = ((unsigned HOST_WIDE_INT) 1 + << floor_log2 (xor_mask.high)) - 1; + may_be_nonzero->low = ALL_ONES; + may_be_nonzero->high |= mask; + must_be_nonzero->low = 0; + must_be_nonzero->high &= ~mask; + } + else if (xor_mask.low != 0) + { + unsigned HOST_WIDE_INT mask + = ((unsigned HOST_WIDE_INT) 1 + << floor_log2 (xor_mask.low)) - 1; + may_be_nonzero->low |= mask; + must_be_nonzero->low &= ~mask; + } + } + + return true; +} + +/* Create two value-ranges in *VR0 and *VR1 from the anti-range *AR + so that *VR0 U *VR1 == *AR. Returns true if that is possible, + false otherwise. If *AR can be represented with a single range + *VR1 will be VR_UNDEFINED. */ + +static bool +ranges_from_anti_range (value_range_t *ar, + value_range_t *vr0, value_range_t *vr1) +{ + tree type = TREE_TYPE (ar->min); + + vr0->type = VR_UNDEFINED; + vr1->type = VR_UNDEFINED; + + if (ar->type != VR_ANTI_RANGE + || TREE_CODE (ar->min) != INTEGER_CST + || TREE_CODE (ar->max) != INTEGER_CST + || !vrp_val_min (type) + || !vrp_val_max (type)) + return false; + + if (!vrp_val_is_min (ar->min)) + { + vr0->type = VR_RANGE; + vr0->min = vrp_val_min (type); + vr0->max + = double_int_to_tree (type, + tree_to_double_int (ar->min) - double_int_one); + } + if (!vrp_val_is_max (ar->max)) + { + vr1->type = VR_RANGE; + vr1->min + = double_int_to_tree (type, + tree_to_double_int (ar->max) + double_int_one); + vr1->max = vrp_val_max (type); + } + if (vr0->type == VR_UNDEFINED) + { + *vr0 = *vr1; + vr1->type = VR_UNDEFINED; + } + + return vr0->type != VR_UNDEFINED; +} + +/* Helper to extract a value-range *VR for a multiplicative operation + *VR0 CODE *VR1. */ + +static void +extract_range_from_multiplicative_op_1 (value_range_t *vr, + enum tree_code code, + value_range_t *vr0, value_range_t *vr1) +{ + enum value_range_type type; + tree val[4]; + size_t i; + tree min, max; + bool sop; + int cmp; + + /* Multiplications, divisions and shifts are a bit tricky to handle, + depending on the mix of signs we have in the two ranges, we + need to operate on different values to get the minimum and + maximum values for the new range. One approach is to figure + out all the variations of range combinations and do the + operations. + + However, this involves several calls to compare_values and it + is pretty convoluted. It's simpler to do the 4 operations + (MIN0 OP MIN1, MIN0 OP MAX1, MAX0 OP MIN1 and MAX0 OP MAX0 OP + MAX1) and then figure the smallest and largest values to form + the new range. */ + gcc_assert (code == MULT_EXPR + || code == TRUNC_DIV_EXPR + || code == FLOOR_DIV_EXPR + || code == CEIL_DIV_EXPR + || code == EXACT_DIV_EXPR + || code == ROUND_DIV_EXPR + || code == RSHIFT_EXPR + || code == LSHIFT_EXPR); + gcc_assert ((vr0->type == VR_RANGE + || (code == MULT_EXPR && vr0->type == VR_ANTI_RANGE)) + && vr0->type == vr1->type); + + type = vr0->type; + + /* Compute the 4 cross operations. */ + sop = false; + val[0] = vrp_int_const_binop (code, vr0->min, vr1->min); + if (val[0] == NULL_TREE) + sop = true; + + if (vr1->max == vr1->min) + val[1] = NULL_TREE; + else + { + val[1] = vrp_int_const_binop (code, vr0->min, vr1->max); + if (val[1] == NULL_TREE) + sop = true; + } + + if (vr0->max == vr0->min) + val[2] = NULL_TREE; + else + { + val[2] = vrp_int_const_binop (code, vr0->max, vr1->min); + if (val[2] == NULL_TREE) + sop = true; + } + + if (vr0->min == vr0->max || vr1->min == vr1->max) + val[3] = NULL_TREE; + else + { + val[3] = vrp_int_const_binop (code, vr0->max, vr1->max); + if (val[3] == NULL_TREE) + sop = true; + } + + if (sop) + { + set_value_range_to_varying (vr); + return; + } + + /* Set MIN to the minimum of VAL[i] and MAX to the maximum + of VAL[i]. */ + min = val[0]; + max = val[0]; + for (i = 1; i < 4; i++) + { + if (!is_gimple_min_invariant (min) + || (TREE_OVERFLOW (min) && !is_overflow_infinity (min)) + || !is_gimple_min_invariant (max) + || (TREE_OVERFLOW (max) && !is_overflow_infinity (max))) + break; + + if (val[i]) + { + if (!is_gimple_min_invariant (val[i]) + || (TREE_OVERFLOW (val[i]) + && !is_overflow_infinity (val[i]))) + { + /* If we found an overflowed value, set MIN and MAX + to it so that we set the resulting range to + VARYING. */ + min = max = val[i]; + break; + } + + if (compare_values (val[i], min) == -1) + min = val[i]; + + if (compare_values (val[i], max) == 1) + max = val[i]; + } + } + + /* If either MIN or MAX overflowed, then set the resulting range to + VARYING. But we do accept an overflow infinity + representation. */ + if (min == NULL_TREE + || !is_gimple_min_invariant (min) + || (TREE_OVERFLOW (min) && !is_overflow_infinity (min)) + || max == NULL_TREE + || !is_gimple_min_invariant (max) + || (TREE_OVERFLOW (max) && !is_overflow_infinity (max))) + { + set_value_range_to_varying (vr); + return; + } + + /* We punt if: + 1) [-INF, +INF] + 2) [-INF, +-INF(OVF)] + 3) [+-INF(OVF), +INF] + 4) [+-INF(OVF), +-INF(OVF)] + We learn nothing when we have INF and INF(OVF) on both sides. + Note that we do accept [-INF, -INF] and [+INF, +INF] without + overflow. */ + if ((vrp_val_is_min (min) || is_overflow_infinity (min)) + && (vrp_val_is_max (max) || is_overflow_infinity (max))) + { + set_value_range_to_varying (vr); + return; + } + + cmp = compare_values (min, max); + if (cmp == -2 || cmp == 1) + { + /* If the new range has its limits swapped around (MIN > MAX), + then the operation caused one of them to wrap around, mark + the new range VARYING. */ + set_value_range_to_varying (vr); + } + else + set_value_range (vr, type, min, max, NULL); +} + +/* Some quadruple precision helpers. */ +static int +quad_int_cmp (double_int l0, double_int h0, + double_int l1, double_int h1, bool uns) +{ + int c = h0.cmp (h1, uns); + if (c != 0) return c; + return l0.ucmp (l1); +} + +static void +quad_int_pair_sort (double_int *l0, double_int *h0, + double_int *l1, double_int *h1, bool uns) +{ + if (quad_int_cmp (*l0, *h0, *l1, *h1, uns) > 0) + { + double_int tmp; + tmp = *l0; *l0 = *l1; *l1 = tmp; + tmp = *h0; *h0 = *h1; *h1 = tmp; + } +} + +/* Extract range information from a binary operation CODE based on + the ranges of each of its operands, *VR0 and *VR1 with resulting + type EXPR_TYPE. The resulting range is stored in *VR. */ + +static void +extract_range_from_binary_expr_1 (value_range_t *vr, + enum tree_code code, tree expr_type, + value_range_t *vr0_, value_range_t *vr1_) +{ + value_range_t vr0 = *vr0_, vr1 = *vr1_; + value_range_t vrtem0 = VR_INITIALIZER, vrtem1 = VR_INITIALIZER; + enum value_range_type type; + tree min = NULL_TREE, max = NULL_TREE; + int cmp; + + if (!INTEGRAL_TYPE_P (expr_type) + && !POINTER_TYPE_P (expr_type)) + { + set_value_range_to_varying (vr); + return; + } + + /* Not all binary expressions can be applied to ranges in a + meaningful way. Handle only arithmetic operations. */ + if (code != PLUS_EXPR + && code != MINUS_EXPR + && code != POINTER_PLUS_EXPR + && code != MULT_EXPR + && code != TRUNC_DIV_EXPR + && code != FLOOR_DIV_EXPR + && code != CEIL_DIV_EXPR + && code != EXACT_DIV_EXPR + && code != ROUND_DIV_EXPR + && code != TRUNC_MOD_EXPR + && code != RSHIFT_EXPR + && code != LSHIFT_EXPR + && code != MIN_EXPR + && code != MAX_EXPR + && code != BIT_AND_EXPR + && code != BIT_IOR_EXPR + && code != BIT_XOR_EXPR) + { + set_value_range_to_varying (vr); + return; + } + + /* If both ranges are UNDEFINED, so is the result. */ + if (vr0.type == VR_UNDEFINED && vr1.type == VR_UNDEFINED) + { + set_value_range_to_undefined (vr); + return; + } + /* If one of the ranges is UNDEFINED drop it to VARYING for the following + code. At some point we may want to special-case operations that + have UNDEFINED result for all or some value-ranges of the not UNDEFINED + operand. */ + else if (vr0.type == VR_UNDEFINED) + set_value_range_to_varying (&vr0); + else if (vr1.type == VR_UNDEFINED) + set_value_range_to_varying (&vr1); + + /* Now canonicalize anti-ranges to ranges when they are not symbolic + and express ~[] op X as ([]' op X) U ([]'' op X). */ + if (vr0.type == VR_ANTI_RANGE + && ranges_from_anti_range (&vr0, &vrtem0, &vrtem1)) + { + extract_range_from_binary_expr_1 (vr, code, expr_type, &vrtem0, vr1_); + if (vrtem1.type != VR_UNDEFINED) + { + value_range_t vrres = VR_INITIALIZER; + extract_range_from_binary_expr_1 (&vrres, code, expr_type, + &vrtem1, vr1_); + vrp_meet (vr, &vrres); + } + return; + } + /* Likewise for X op ~[]. */ + if (vr1.type == VR_ANTI_RANGE + && ranges_from_anti_range (&vr1, &vrtem0, &vrtem1)) + { + extract_range_from_binary_expr_1 (vr, code, expr_type, vr0_, &vrtem0); + if (vrtem1.type != VR_UNDEFINED) + { + value_range_t vrres = VR_INITIALIZER; + extract_range_from_binary_expr_1 (&vrres, code, expr_type, + vr0_, &vrtem1); + vrp_meet (vr, &vrres); + } + return; + } + + /* The type of the resulting value range defaults to VR0.TYPE. */ + type = vr0.type; + + /* Refuse to operate on VARYING ranges, ranges of different kinds + and symbolic ranges. As an exception, we allow BIT_AND_EXPR + because we may be able to derive a useful range even if one of + the operands is VR_VARYING or symbolic range. Similarly for + divisions. TODO, we may be able to derive anti-ranges in + some cases. */ + if (code != BIT_AND_EXPR + && code != BIT_IOR_EXPR + && code != TRUNC_DIV_EXPR + && code != FLOOR_DIV_EXPR + && code != CEIL_DIV_EXPR + && code != EXACT_DIV_EXPR + && code != ROUND_DIV_EXPR + && code != TRUNC_MOD_EXPR + && code != MIN_EXPR + && code != MAX_EXPR + && (vr0.type == VR_VARYING + || vr1.type == VR_VARYING + || vr0.type != vr1.type + || symbolic_range_p (&vr0) + || symbolic_range_p (&vr1))) + { + set_value_range_to_varying (vr); + return; + } + + /* Now evaluate the expression to determine the new range. */ + if (POINTER_TYPE_P (expr_type)) + { + if (code == MIN_EXPR || code == MAX_EXPR) + { + /* For MIN/MAX expressions with pointers, we only care about + nullness, if both are non null, then the result is nonnull. + If both are null, then the result is null. Otherwise they + are varying. */ + if (range_is_nonnull (&vr0) && range_is_nonnull (&vr1)) + set_value_range_to_nonnull (vr, expr_type); + else if (range_is_null (&vr0) && range_is_null (&vr1)) + set_value_range_to_null (vr, expr_type); + else + set_value_range_to_varying (vr); + } + else if (code == POINTER_PLUS_EXPR) + { + /* For pointer types, we are really only interested in asserting + whether the expression evaluates to non-NULL. */ + if (range_is_nonnull (&vr0) || range_is_nonnull (&vr1)) + set_value_range_to_nonnull (vr, expr_type); + else if (range_is_null (&vr0) && range_is_null (&vr1)) + set_value_range_to_null (vr, expr_type); + else + set_value_range_to_varying (vr); + } + else if (code == BIT_AND_EXPR) + { + /* For pointer types, we are really only interested in asserting + whether the expression evaluates to non-NULL. */ + if (range_is_nonnull (&vr0) && range_is_nonnull (&vr1)) + set_value_range_to_nonnull (vr, expr_type); + else if (range_is_null (&vr0) || range_is_null (&vr1)) + set_value_range_to_null (vr, expr_type); + else + set_value_range_to_varying (vr); + } + else + set_value_range_to_varying (vr); + + return; + } + + /* For integer ranges, apply the operation to each end of the + range and see what we end up with. */ + if (code == PLUS_EXPR || code == MINUS_EXPR) + { + /* If we have a PLUS_EXPR with two VR_RANGE integer constant + ranges compute the precise range for such case if possible. */ + if (range_int_cst_p (&vr0) + && range_int_cst_p (&vr1) + /* We need as many bits as the possibly unsigned inputs. */ + && TYPE_PRECISION (expr_type) <= HOST_BITS_PER_DOUBLE_INT) + { + double_int min0 = tree_to_double_int (vr0.min); + double_int max0 = tree_to_double_int (vr0.max); + double_int min1 = tree_to_double_int (vr1.min); + double_int max1 = tree_to_double_int (vr1.max); + bool uns = TYPE_UNSIGNED (expr_type); + double_int type_min + = double_int::min_value (TYPE_PRECISION (expr_type), uns); + double_int type_max + = double_int::max_value (TYPE_PRECISION (expr_type), uns); + double_int dmin, dmax; + int min_ovf = 0; + int max_ovf = 0; + + if (code == PLUS_EXPR) + { + dmin = min0 + min1; + dmax = max0 + max1; + + /* Check for overflow in double_int. */ + if (min1.cmp (double_int_zero, uns) != dmin.cmp (min0, uns)) + min_ovf = min0.cmp (dmin, uns); + if (max1.cmp (double_int_zero, uns) != dmax.cmp (max0, uns)) + max_ovf = max0.cmp (dmax, uns); + } + else /* if (code == MINUS_EXPR) */ + { + dmin = min0 - max1; + dmax = max0 - min1; + + if (double_int_zero.cmp (max1, uns) != dmin.cmp (min0, uns)) + min_ovf = min0.cmp (max1, uns); + if (double_int_zero.cmp (min1, uns) != dmax.cmp (max0, uns)) + max_ovf = max0.cmp (min1, uns); + } + + /* For non-wrapping arithmetic look at possibly smaller + value-ranges of the type. */ + if (!TYPE_OVERFLOW_WRAPS (expr_type)) + { + if (vrp_val_min (expr_type)) + type_min = tree_to_double_int (vrp_val_min (expr_type)); + if (vrp_val_max (expr_type)) + type_max = tree_to_double_int (vrp_val_max (expr_type)); + } + + /* Check for type overflow. */ + if (min_ovf == 0) + { + if (dmin.cmp (type_min, uns) == -1) + min_ovf = -1; + else if (dmin.cmp (type_max, uns) == 1) + min_ovf = 1; + } + if (max_ovf == 0) + { + if (dmax.cmp (type_min, uns) == -1) + max_ovf = -1; + else if (dmax.cmp (type_max, uns) == 1) + max_ovf = 1; + } + + if (TYPE_OVERFLOW_WRAPS (expr_type)) + { + /* If overflow wraps, truncate the values and adjust the + range kind and bounds appropriately. */ + double_int tmin + = dmin.ext (TYPE_PRECISION (expr_type), uns); + double_int tmax + = dmax.ext (TYPE_PRECISION (expr_type), uns); + if (min_ovf == max_ovf) + { + /* No overflow or both overflow or underflow. The + range kind stays VR_RANGE. */ + min = double_int_to_tree (expr_type, tmin); + max = double_int_to_tree (expr_type, tmax); + } + else if (min_ovf == -1 + && max_ovf == 1) + { + /* Underflow and overflow, drop to VR_VARYING. */ + set_value_range_to_varying (vr); + return; + } + else + { + /* Min underflow or max overflow. The range kind + changes to VR_ANTI_RANGE. */ + bool covers = false; + double_int tem = tmin; + gcc_assert ((min_ovf == -1 && max_ovf == 0) + || (max_ovf == 1 && min_ovf == 0)); + type = VR_ANTI_RANGE; + tmin = tmax + double_int_one; + if (tmin.cmp (tmax, uns) < 0) + covers = true; + tmax = tem + double_int_minus_one; + if (tmax.cmp (tem, uns) > 0) + covers = true; + /* If the anti-range would cover nothing, drop to varying. + Likewise if the anti-range bounds are outside of the + types values. */ + if (covers || tmin.cmp (tmax, uns) > 0) + { + set_value_range_to_varying (vr); + return; + } + min = double_int_to_tree (expr_type, tmin); + max = double_int_to_tree (expr_type, tmax); + } + } + else + { + /* If overflow does not wrap, saturate to the types min/max + value. */ + if (min_ovf == -1) + { + if (needs_overflow_infinity (expr_type) + && supports_overflow_infinity (expr_type)) + min = negative_overflow_infinity (expr_type); + else + min = double_int_to_tree (expr_type, type_min); + } + else if (min_ovf == 1) + { + if (needs_overflow_infinity (expr_type) + && supports_overflow_infinity (expr_type)) + min = positive_overflow_infinity (expr_type); + else + min = double_int_to_tree (expr_type, type_max); + } + else + min = double_int_to_tree (expr_type, dmin); + + if (max_ovf == -1) + { + if (needs_overflow_infinity (expr_type) + && supports_overflow_infinity (expr_type)) + max = negative_overflow_infinity (expr_type); + else + max = double_int_to_tree (expr_type, type_min); + } + else if (max_ovf == 1) + { + if (needs_overflow_infinity (expr_type) + && supports_overflow_infinity (expr_type)) + max = positive_overflow_infinity (expr_type); + else + max = double_int_to_tree (expr_type, type_max); + } + else + max = double_int_to_tree (expr_type, dmax); + } + if (needs_overflow_infinity (expr_type) + && supports_overflow_infinity (expr_type)) + { + if (is_negative_overflow_infinity (vr0.min) + || (code == PLUS_EXPR + ? is_negative_overflow_infinity (vr1.min) + : is_positive_overflow_infinity (vr1.max))) + min = negative_overflow_infinity (expr_type); + if (is_positive_overflow_infinity (vr0.max) + || (code == PLUS_EXPR + ? is_positive_overflow_infinity (vr1.max) + : is_negative_overflow_infinity (vr1.min))) + max = positive_overflow_infinity (expr_type); + } + } + else + { + /* For other cases, for example if we have a PLUS_EXPR with two + VR_ANTI_RANGEs, drop to VR_VARYING. It would take more effort + to compute a precise range for such a case. + ??? General even mixed range kind operations can be expressed + by for example transforming ~[3, 5] + [1, 2] to range-only + operations and a union primitive: + [-INF, 2] + [1, 2] U [5, +INF] + [1, 2] + [-INF+1, 4] U [6, +INF(OVF)] + though usually the union is not exactly representable with + a single range or anti-range as the above is + [-INF+1, +INF(OVF)] intersected with ~[5, 5] + but one could use a scheme similar to equivalences for this. */ + set_value_range_to_varying (vr); + return; + } + } + else if (code == MIN_EXPR + || code == MAX_EXPR) + { + if (vr0.type == VR_RANGE + && !symbolic_range_p (&vr0)) + { + type = VR_RANGE; + if (vr1.type == VR_RANGE + && !symbolic_range_p (&vr1)) + { + /* For operations that make the resulting range directly + proportional to the original ranges, apply the operation to + the same end of each range. */ + min = vrp_int_const_binop (code, vr0.min, vr1.min); + max = vrp_int_const_binop (code, vr0.max, vr1.max); + } + else if (code == MIN_EXPR) + { + min = vrp_val_min (expr_type); + max = vr0.max; + } + else if (code == MAX_EXPR) + { + min = vr0.min; + max = vrp_val_max (expr_type); + } + } + else if (vr1.type == VR_RANGE + && !symbolic_range_p (&vr1)) + { + type = VR_RANGE; + if (code == MIN_EXPR) + { + min = vrp_val_min (expr_type); + max = vr1.max; + } + else if (code == MAX_EXPR) + { + min = vr1.min; + max = vrp_val_max (expr_type); + } + } + else + { + set_value_range_to_varying (vr); + return; + } + } + else if (code == MULT_EXPR) + { + /* Fancy code so that with unsigned, [-3,-1]*[-3,-1] does not + drop to varying. */ + if (range_int_cst_p (&vr0) + && range_int_cst_p (&vr1) + && TYPE_OVERFLOW_WRAPS (expr_type)) + { + double_int min0, max0, min1, max1, sizem1, size; + double_int prod0l, prod0h, prod1l, prod1h, + prod2l, prod2h, prod3l, prod3h; + bool uns0, uns1, uns; + + sizem1 = double_int::max_value (TYPE_PRECISION (expr_type), true); + size = sizem1 + double_int_one; + + min0 = tree_to_double_int (vr0.min); + max0 = tree_to_double_int (vr0.max); + min1 = tree_to_double_int (vr1.min); + max1 = tree_to_double_int (vr1.max); + + uns0 = TYPE_UNSIGNED (expr_type); + uns1 = uns0; + + /* Canonicalize the intervals. */ + if (TYPE_UNSIGNED (expr_type)) + { + double_int min2 = size - min0; + if (!min2.is_zero () && min2.cmp (max0, true) < 0) + { + min0 = -min2; + max0 -= size; + uns0 = false; + } + + min2 = size - min1; + if (!min2.is_zero () && min2.cmp (max1, true) < 0) + { + min1 = -min2; + max1 -= size; + uns1 = false; + } + } + uns = uns0 & uns1; + + bool overflow; + prod0l = min0.wide_mul_with_sign (min1, true, &prod0h, &overflow); + if (!uns0 && min0.is_negative ()) + prod0h -= min1; + if (!uns1 && min1.is_negative ()) + prod0h -= min0; + + prod1l = min0.wide_mul_with_sign (max1, true, &prod1h, &overflow); + if (!uns0 && min0.is_negative ()) + prod1h -= max1; + if (!uns1 && max1.is_negative ()) + prod1h -= min0; + + prod2l = max0.wide_mul_with_sign (min1, true, &prod2h, &overflow); + if (!uns0 && max0.is_negative ()) + prod2h -= min1; + if (!uns1 && min1.is_negative ()) + prod2h -= max0; + + prod3l = max0.wide_mul_with_sign (max1, true, &prod3h, &overflow); + if (!uns0 && max0.is_negative ()) + prod3h -= max1; + if (!uns1 && max1.is_negative ()) + prod3h -= max0; + + /* Sort the 4 products. */ + quad_int_pair_sort (&prod0l, &prod0h, &prod3l, &prod3h, uns); + quad_int_pair_sort (&prod1l, &prod1h, &prod2l, &prod2h, uns); + quad_int_pair_sort (&prod0l, &prod0h, &prod1l, &prod1h, uns); + quad_int_pair_sort (&prod2l, &prod2h, &prod3l, &prod3h, uns); + + /* Max - min. */ + if (prod0l.is_zero ()) + { + prod1l = double_int_zero; + prod1h = -prod0h; + } + else + { + prod1l = -prod0l; + prod1h = ~prod0h; + } + prod2l = prod3l + prod1l; + prod2h = prod3h + prod1h; + if (prod2l.ult (prod3l)) + prod2h += double_int_one; /* carry */ + + if (!prod2h.is_zero () + || prod2l.cmp (sizem1, true) >= 0) + { + /* the range covers all values. */ + set_value_range_to_varying (vr); + return; + } + + /* The following should handle the wrapping and selecting + VR_ANTI_RANGE for us. */ + min = double_int_to_tree (expr_type, prod0l); + max = double_int_to_tree (expr_type, prod3l); + set_and_canonicalize_value_range (vr, VR_RANGE, min, max, NULL); + return; + } + + /* If we have an unsigned MULT_EXPR with two VR_ANTI_RANGEs, + drop to VR_VARYING. It would take more effort to compute a + precise range for such a case. For example, if we have + op0 == 65536 and op1 == 65536 with their ranges both being + ~[0,0] on a 32-bit machine, we would have op0 * op1 == 0, so + we cannot claim that the product is in ~[0,0]. Note that we + are guaranteed to have vr0.type == vr1.type at this + point. */ + if (vr0.type == VR_ANTI_RANGE + && !TYPE_OVERFLOW_UNDEFINED (expr_type)) + { + set_value_range_to_varying (vr); + return; + } + + extract_range_from_multiplicative_op_1 (vr, code, &vr0, &vr1); + return; + } + else if (code == RSHIFT_EXPR + || code == LSHIFT_EXPR) + { + /* If we have a RSHIFT_EXPR with any shift values outside [0..prec-1], + then drop to VR_VARYING. Outside of this range we get undefined + behavior from the shift operation. We cannot even trust + SHIFT_COUNT_TRUNCATED at this stage, because that applies to rtl + shifts, and the operation at the tree level may be widened. */ + if (range_int_cst_p (&vr1) + && compare_tree_int (vr1.min, 0) >= 0 + && compare_tree_int (vr1.max, TYPE_PRECISION (expr_type)) == -1) + { + if (code == RSHIFT_EXPR) + { + extract_range_from_multiplicative_op_1 (vr, code, &vr0, &vr1); + return; + } + /* We can map lshifts by constants to MULT_EXPR handling. */ + else if (code == LSHIFT_EXPR + && range_int_cst_singleton_p (&vr1)) + { + bool saved_flag_wrapv; + value_range_t vr1p = VR_INITIALIZER; + vr1p.type = VR_RANGE; + vr1p.min + = double_int_to_tree (expr_type, + double_int_one + .llshift (TREE_INT_CST_LOW (vr1.min), + TYPE_PRECISION (expr_type))); + vr1p.max = vr1p.min; + /* We have to use a wrapping multiply though as signed overflow + on lshifts is implementation defined in C89. */ + saved_flag_wrapv = flag_wrapv; + flag_wrapv = 1; + extract_range_from_binary_expr_1 (vr, MULT_EXPR, expr_type, + &vr0, &vr1p); + flag_wrapv = saved_flag_wrapv; + return; + } + else if (code == LSHIFT_EXPR + && range_int_cst_p (&vr0)) + { + int prec = TYPE_PRECISION (expr_type); + int overflow_pos = prec; + int bound_shift; + double_int bound, complement, low_bound, high_bound; + bool uns = TYPE_UNSIGNED (expr_type); + bool in_bounds = false; + + if (!uns) + overflow_pos -= 1; + + bound_shift = overflow_pos - TREE_INT_CST_LOW (vr1.max); + /* If bound_shift == HOST_BITS_PER_DOUBLE_INT, the llshift can + overflow. However, for that to happen, vr1.max needs to be + zero, which means vr1 is a singleton range of zero, which + means it should be handled by the previous LSHIFT_EXPR + if-clause. */ + bound = double_int_one.llshift (bound_shift, prec); + complement = ~(bound - double_int_one); + + if (uns) + { + low_bound = bound.zext (prec); + high_bound = complement.zext (prec); + if (tree_to_double_int (vr0.max).ult (low_bound)) + { + /* [5, 6] << [1, 2] == [10, 24]. */ + /* We're shifting out only zeroes, the value increases + monotonically. */ + in_bounds = true; + } + else if (high_bound.ult (tree_to_double_int (vr0.min))) + { + /* [0xffffff00, 0xffffffff] << [1, 2] + == [0xfffffc00, 0xfffffffe]. */ + /* We're shifting out only ones, the value decreases + monotonically. */ + in_bounds = true; + } + } + else + { + /* [-1, 1] << [1, 2] == [-4, 4]. */ + low_bound = complement.sext (prec); + high_bound = bound; + if (tree_to_double_int (vr0.max).slt (high_bound) + && low_bound.slt (tree_to_double_int (vr0.min))) + { + /* For non-negative numbers, we're shifting out only + zeroes, the value increases monotonically. + For negative numbers, we're shifting out only ones, the + value decreases monotomically. */ + in_bounds = true; + } + } + + if (in_bounds) + { + extract_range_from_multiplicative_op_1 (vr, code, &vr0, &vr1); + return; + } + } + } + set_value_range_to_varying (vr); + return; + } + else if (code == TRUNC_DIV_EXPR + || code == FLOOR_DIV_EXPR + || code == CEIL_DIV_EXPR + || code == EXACT_DIV_EXPR + || code == ROUND_DIV_EXPR) + { + if (vr0.type != VR_RANGE || symbolic_range_p (&vr0)) + { + /* For division, if op1 has VR_RANGE but op0 does not, something + can be deduced just from that range. Say [min, max] / [4, max] + gives [min / 4, max / 4] range. */ + if (vr1.type == VR_RANGE + && !symbolic_range_p (&vr1) + && range_includes_zero_p (vr1.min, vr1.max) == 0) + { + vr0.type = type = VR_RANGE; + vr0.min = vrp_val_min (expr_type); + vr0.max = vrp_val_max (expr_type); + } + else + { + set_value_range_to_varying (vr); + return; + } + } + + /* For divisions, if flag_non_call_exceptions is true, we must + not eliminate a division by zero. */ + if (cfun->can_throw_non_call_exceptions + && (vr1.type != VR_RANGE + || range_includes_zero_p (vr1.min, vr1.max) != 0)) + { + set_value_range_to_varying (vr); + return; + } + + /* For divisions, if op0 is VR_RANGE, we can deduce a range + even if op1 is VR_VARYING, VR_ANTI_RANGE, symbolic or can + include 0. */ + if (vr0.type == VR_RANGE + && (vr1.type != VR_RANGE + || range_includes_zero_p (vr1.min, vr1.max) != 0)) + { + tree zero = build_int_cst (TREE_TYPE (vr0.min), 0); + int cmp; + + min = NULL_TREE; + max = NULL_TREE; + if (TYPE_UNSIGNED (expr_type) + || value_range_nonnegative_p (&vr1)) + { + /* For unsigned division or when divisor is known + to be non-negative, the range has to cover + all numbers from 0 to max for positive max + and all numbers from min to 0 for negative min. */ + cmp = compare_values (vr0.max, zero); + if (cmp == -1) + max = zero; + else if (cmp == 0 || cmp == 1) + max = vr0.max; + else + type = VR_VARYING; + cmp = compare_values (vr0.min, zero); + if (cmp == 1) + min = zero; + else if (cmp == 0 || cmp == -1) + min = vr0.min; + else + type = VR_VARYING; + } + else + { + /* Otherwise the range is -max .. max or min .. -min + depending on which bound is bigger in absolute value, + as the division can change the sign. */ + abs_extent_range (vr, vr0.min, vr0.max); + return; + } + if (type == VR_VARYING) + { + set_value_range_to_varying (vr); + return; + } + } + else + { + extract_range_from_multiplicative_op_1 (vr, code, &vr0, &vr1); + return; + } + } + else if (code == TRUNC_MOD_EXPR) + { + if (vr1.type != VR_RANGE + || range_includes_zero_p (vr1.min, vr1.max) != 0 + || vrp_val_is_min (vr1.min)) + { + set_value_range_to_varying (vr); + return; + } + type = VR_RANGE; + /* Compute MAX <|vr1.min|, |vr1.max|> - 1. */ + max = fold_unary_to_constant (ABS_EXPR, expr_type, vr1.min); + if (tree_int_cst_lt (max, vr1.max)) + max = vr1.max; + max = int_const_binop (MINUS_EXPR, max, integer_one_node); + /* If the dividend is non-negative the modulus will be + non-negative as well. */ + if (TYPE_UNSIGNED (expr_type) + || value_range_nonnegative_p (&vr0)) + min = build_int_cst (TREE_TYPE (max), 0); + else + min = fold_unary_to_constant (NEGATE_EXPR, expr_type, max); + } + else if (code == BIT_AND_EXPR || code == BIT_IOR_EXPR || code == BIT_XOR_EXPR) + { + bool int_cst_range0, int_cst_range1; + double_int may_be_nonzero0, may_be_nonzero1; + double_int must_be_nonzero0, must_be_nonzero1; + + int_cst_range0 = zero_nonzero_bits_from_vr (&vr0, &may_be_nonzero0, + &must_be_nonzero0); + int_cst_range1 = zero_nonzero_bits_from_vr (&vr1, &may_be_nonzero1, + &must_be_nonzero1); + + type = VR_RANGE; + if (code == BIT_AND_EXPR) + { + double_int dmax; + min = double_int_to_tree (expr_type, + must_be_nonzero0 & must_be_nonzero1); + dmax = may_be_nonzero0 & may_be_nonzero1; + /* If both input ranges contain only negative values we can + truncate the result range maximum to the minimum of the + input range maxima. */ + if (int_cst_range0 && int_cst_range1 + && tree_int_cst_sgn (vr0.max) < 0 + && tree_int_cst_sgn (vr1.max) < 0) + { + dmax = dmax.min (tree_to_double_int (vr0.max), + TYPE_UNSIGNED (expr_type)); + dmax = dmax.min (tree_to_double_int (vr1.max), + TYPE_UNSIGNED (expr_type)); + } + /* If either input range contains only non-negative values + we can truncate the result range maximum to the respective + maximum of the input range. */ + if (int_cst_range0 && tree_int_cst_sgn (vr0.min) >= 0) + dmax = dmax.min (tree_to_double_int (vr0.max), + TYPE_UNSIGNED (expr_type)); + if (int_cst_range1 && tree_int_cst_sgn (vr1.min) >= 0) + dmax = dmax.min (tree_to_double_int (vr1.max), + TYPE_UNSIGNED (expr_type)); + max = double_int_to_tree (expr_type, dmax); + } + else if (code == BIT_IOR_EXPR) + { + double_int dmin; + max = double_int_to_tree (expr_type, + may_be_nonzero0 | may_be_nonzero1); + dmin = must_be_nonzero0 | must_be_nonzero1; + /* If the input ranges contain only positive values we can + truncate the minimum of the result range to the maximum + of the input range minima. */ + if (int_cst_range0 && int_cst_range1 + && tree_int_cst_sgn (vr0.min) >= 0 + && tree_int_cst_sgn (vr1.min) >= 0) + { + dmin = dmin.max (tree_to_double_int (vr0.min), + TYPE_UNSIGNED (expr_type)); + dmin = dmin.max (tree_to_double_int (vr1.min), + TYPE_UNSIGNED (expr_type)); + } + /* If either input range contains only negative values + we can truncate the minimum of the result range to the + respective minimum range. */ + if (int_cst_range0 && tree_int_cst_sgn (vr0.max) < 0) + dmin = dmin.max (tree_to_double_int (vr0.min), + TYPE_UNSIGNED (expr_type)); + if (int_cst_range1 && tree_int_cst_sgn (vr1.max) < 0) + dmin = dmin.max (tree_to_double_int (vr1.min), + TYPE_UNSIGNED (expr_type)); + min = double_int_to_tree (expr_type, dmin); + } + else if (code == BIT_XOR_EXPR) + { + double_int result_zero_bits, result_one_bits; + result_zero_bits = (must_be_nonzero0 & must_be_nonzero1) + | ~(may_be_nonzero0 | may_be_nonzero1); + result_one_bits = must_be_nonzero0.and_not (may_be_nonzero1) + | must_be_nonzero1.and_not (may_be_nonzero0); + max = double_int_to_tree (expr_type, ~result_zero_bits); + min = double_int_to_tree (expr_type, result_one_bits); + /* If the range has all positive or all negative values the + result is better than VARYING. */ + if (tree_int_cst_sgn (min) < 0 + || tree_int_cst_sgn (max) >= 0) + ; + else + max = min = NULL_TREE; + } + } + else + gcc_unreachable (); + + /* If either MIN or MAX overflowed, then set the resulting range to + VARYING. But we do accept an overflow infinity + representation. */ + if (min == NULL_TREE + || !is_gimple_min_invariant (min) + || (TREE_OVERFLOW (min) && !is_overflow_infinity (min)) + || max == NULL_TREE + || !is_gimple_min_invariant (max) + || (TREE_OVERFLOW (max) && !is_overflow_infinity (max))) + { + set_value_range_to_varying (vr); + return; + } + + /* We punt if: + 1) [-INF, +INF] + 2) [-INF, +-INF(OVF)] + 3) [+-INF(OVF), +INF] + 4) [+-INF(OVF), +-INF(OVF)] + We learn nothing when we have INF and INF(OVF) on both sides. + Note that we do accept [-INF, -INF] and [+INF, +INF] without + overflow. */ + if ((vrp_val_is_min (min) || is_overflow_infinity (min)) + && (vrp_val_is_max (max) || is_overflow_infinity (max))) + { + set_value_range_to_varying (vr); + return; + } + + cmp = compare_values (min, max); + if (cmp == -2 || cmp == 1) + { + /* If the new range has its limits swapped around (MIN > MAX), + then the operation caused one of them to wrap around, mark + the new range VARYING. */ + set_value_range_to_varying (vr); + } + else + set_value_range (vr, type, min, max, NULL); +} + +/* Extract range information from a binary expression OP0 CODE OP1 based on + the ranges of each of its operands with resulting type EXPR_TYPE. + The resulting range is stored in *VR. */ + +static void +extract_range_from_binary_expr (value_range_t *vr, + enum tree_code code, + tree expr_type, tree op0, tree op1) +{ + value_range_t vr0 = VR_INITIALIZER; + value_range_t vr1 = VR_INITIALIZER; + + /* Get value ranges for each operand. For constant operands, create + a new value range with the operand to simplify processing. */ + if (TREE_CODE (op0) == SSA_NAME) + vr0 = *(get_value_range (op0)); + else if (is_gimple_min_invariant (op0)) + set_value_range_to_value (&vr0, op0, NULL); + else + set_value_range_to_varying (&vr0); + + if (TREE_CODE (op1) == SSA_NAME) + vr1 = *(get_value_range (op1)); + else if (is_gimple_min_invariant (op1)) + set_value_range_to_value (&vr1, op1, NULL); + else + set_value_range_to_varying (&vr1); + + extract_range_from_binary_expr_1 (vr, code, expr_type, &vr0, &vr1); +} + +/* Extract range information from a unary operation CODE based on + the range of its operand *VR0 with type OP0_TYPE with resulting type TYPE. + The The resulting range is stored in *VR. */ + +static void +extract_range_from_unary_expr_1 (value_range_t *vr, + enum tree_code code, tree type, + value_range_t *vr0_, tree op0_type) +{ + value_range_t vr0 = *vr0_, vrtem0 = VR_INITIALIZER, vrtem1 = VR_INITIALIZER; + + /* VRP only operates on integral and pointer types. */ + if (!(INTEGRAL_TYPE_P (op0_type) + || POINTER_TYPE_P (op0_type)) + || !(INTEGRAL_TYPE_P (type) + || POINTER_TYPE_P (type))) + { + set_value_range_to_varying (vr); + return; + } + + /* If VR0 is UNDEFINED, so is the result. */ + if (vr0.type == VR_UNDEFINED) + { + set_value_range_to_undefined (vr); + return; + } + + /* Handle operations that we express in terms of others. */ + if (code == PAREN_EXPR || code == OBJ_TYPE_REF) + { + /* PAREN_EXPR and OBJ_TYPE_REF are simple copies. */ + copy_value_range (vr, &vr0); + return; + } + else if (code == NEGATE_EXPR) + { + /* -X is simply 0 - X, so re-use existing code that also handles + anti-ranges fine. */ + value_range_t zero = VR_INITIALIZER; + set_value_range_to_value (&zero, build_int_cst (type, 0), NULL); + extract_range_from_binary_expr_1 (vr, MINUS_EXPR, type, &zero, &vr0); + return; + } + else if (code == BIT_NOT_EXPR) + { + /* ~X is simply -1 - X, so re-use existing code that also handles + anti-ranges fine. */ + value_range_t minusone = VR_INITIALIZER; + set_value_range_to_value (&minusone, build_int_cst (type, -1), NULL); + extract_range_from_binary_expr_1 (vr, MINUS_EXPR, + type, &minusone, &vr0); + return; + } + + /* Now canonicalize anti-ranges to ranges when they are not symbolic + and express op ~[] as (op []') U (op []''). */ + if (vr0.type == VR_ANTI_RANGE + && ranges_from_anti_range (&vr0, &vrtem0, &vrtem1)) + { + extract_range_from_unary_expr_1 (vr, code, type, &vrtem0, op0_type); + if (vrtem1.type != VR_UNDEFINED) + { + value_range_t vrres = VR_INITIALIZER; + extract_range_from_unary_expr_1 (&vrres, code, type, + &vrtem1, op0_type); + vrp_meet (vr, &vrres); + } + return; + } + + if (CONVERT_EXPR_CODE_P (code)) + { + tree inner_type = op0_type; + tree outer_type = type; + + /* If the expression evaluates to a pointer, we are only interested in + determining if it evaluates to NULL [0, 0] or non-NULL (~[0, 0]). */ + if (POINTER_TYPE_P (type)) + { + if (range_is_nonnull (&vr0)) + set_value_range_to_nonnull (vr, type); + else if (range_is_null (&vr0)) + set_value_range_to_null (vr, type); + else + set_value_range_to_varying (vr); + return; + } + + /* If VR0 is varying and we increase the type precision, assume + a full range for the following transformation. */ + if (vr0.type == VR_VARYING + && INTEGRAL_TYPE_P (inner_type) + && TYPE_PRECISION (inner_type) < TYPE_PRECISION (outer_type)) + { + vr0.type = VR_RANGE; + vr0.min = TYPE_MIN_VALUE (inner_type); + vr0.max = TYPE_MAX_VALUE (inner_type); + } + + /* If VR0 is a constant range or anti-range and the conversion is + not truncating we can convert the min and max values and + canonicalize the resulting range. Otherwise we can do the + conversion if the size of the range is less than what the + precision of the target type can represent and the range is + not an anti-range. */ + if ((vr0.type == VR_RANGE + || vr0.type == VR_ANTI_RANGE) + && TREE_CODE (vr0.min) == INTEGER_CST + && TREE_CODE (vr0.max) == INTEGER_CST + && (!is_overflow_infinity (vr0.min) + || (vr0.type == VR_RANGE + && TYPE_PRECISION (outer_type) > TYPE_PRECISION (inner_type) + && needs_overflow_infinity (outer_type) + && supports_overflow_infinity (outer_type))) + && (!is_overflow_infinity (vr0.max) + || (vr0.type == VR_RANGE + && TYPE_PRECISION (outer_type) > TYPE_PRECISION (inner_type) + && needs_overflow_infinity (outer_type) + && supports_overflow_infinity (outer_type))) + && (TYPE_PRECISION (outer_type) >= TYPE_PRECISION (inner_type) + || (vr0.type == VR_RANGE + && integer_zerop (int_const_binop (RSHIFT_EXPR, + int_const_binop (MINUS_EXPR, vr0.max, vr0.min), + size_int (TYPE_PRECISION (outer_type))))))) + { + tree new_min, new_max; + if (is_overflow_infinity (vr0.min)) + new_min = negative_overflow_infinity (outer_type); + else + new_min = force_fit_type_double (outer_type, + tree_to_double_int (vr0.min), + 0, false); + if (is_overflow_infinity (vr0.max)) + new_max = positive_overflow_infinity (outer_type); + else + new_max = force_fit_type_double (outer_type, + tree_to_double_int (vr0.max), + 0, false); + set_and_canonicalize_value_range (vr, vr0.type, + new_min, new_max, NULL); + return; + } + + set_value_range_to_varying (vr); + return; + } + else if (code == ABS_EXPR) + { + tree min, max; + int cmp; + + /* Pass through vr0 in the easy cases. */ + if (TYPE_UNSIGNED (type) + || value_range_nonnegative_p (&vr0)) + { + copy_value_range (vr, &vr0); + return; + } + + /* For the remaining varying or symbolic ranges we can't do anything + useful. */ + if (vr0.type == VR_VARYING + || symbolic_range_p (&vr0)) + { + set_value_range_to_varying (vr); + return; + } + + /* -TYPE_MIN_VALUE = TYPE_MIN_VALUE with flag_wrapv so we can't get a + useful range. */ + if (!TYPE_OVERFLOW_UNDEFINED (type) + && ((vr0.type == VR_RANGE + && vrp_val_is_min (vr0.min)) + || (vr0.type == VR_ANTI_RANGE + && !vrp_val_is_min (vr0.min)))) + { + set_value_range_to_varying (vr); + return; + } + + /* ABS_EXPR may flip the range around, if the original range + included negative values. */ + if (is_overflow_infinity (vr0.min)) + min = positive_overflow_infinity (type); + else if (!vrp_val_is_min (vr0.min)) + min = fold_unary_to_constant (code, type, vr0.min); + else if (!needs_overflow_infinity (type)) + min = TYPE_MAX_VALUE (type); + else if (supports_overflow_infinity (type)) + min = positive_overflow_infinity (type); + else + { + set_value_range_to_varying (vr); + return; + } + + if (is_overflow_infinity (vr0.max)) + max = positive_overflow_infinity (type); + else if (!vrp_val_is_min (vr0.max)) + max = fold_unary_to_constant (code, type, vr0.max); + else if (!needs_overflow_infinity (type)) + max = TYPE_MAX_VALUE (type); + else if (supports_overflow_infinity (type) + /* We shouldn't generate [+INF, +INF] as set_value_range + doesn't like this and ICEs. */ + && !is_positive_overflow_infinity (min)) + max = positive_overflow_infinity (type); + else + { + set_value_range_to_varying (vr); + return; + } + + cmp = compare_values (min, max); + + /* If a VR_ANTI_RANGEs contains zero, then we have + ~[-INF, min(MIN, MAX)]. */ + if (vr0.type == VR_ANTI_RANGE) + { + if (range_includes_zero_p (vr0.min, vr0.max) == 1) + { + /* Take the lower of the two values. */ + if (cmp != 1) + max = min; + + /* Create ~[-INF, min (abs(MIN), abs(MAX))] + or ~[-INF + 1, min (abs(MIN), abs(MAX))] when + flag_wrapv is set and the original anti-range doesn't include + TYPE_MIN_VALUE, remember -TYPE_MIN_VALUE = TYPE_MIN_VALUE. */ + if (TYPE_OVERFLOW_WRAPS (type)) + { + tree type_min_value = TYPE_MIN_VALUE (type); + + min = (vr0.min != type_min_value + ? int_const_binop (PLUS_EXPR, type_min_value, + integer_one_node) + : type_min_value); + } + else + { + if (overflow_infinity_range_p (&vr0)) + min = negative_overflow_infinity (type); + else + min = TYPE_MIN_VALUE (type); + } + } + else + { + /* All else has failed, so create the range [0, INF], even for + flag_wrapv since TYPE_MIN_VALUE is in the original + anti-range. */ + vr0.type = VR_RANGE; + min = build_int_cst (type, 0); + if (needs_overflow_infinity (type)) + { + if (supports_overflow_infinity (type)) + max = positive_overflow_infinity (type); + else + { + set_value_range_to_varying (vr); + return; + } + } + else + max = TYPE_MAX_VALUE (type); + } + } + + /* If the range contains zero then we know that the minimum value in the + range will be zero. */ + else if (range_includes_zero_p (vr0.min, vr0.max) == 1) + { + if (cmp == 1) + max = min; + min = build_int_cst (type, 0); + } + else + { + /* If the range was reversed, swap MIN and MAX. */ + if (cmp == 1) + { + tree t = min; + min = max; + max = t; + } + } + + cmp = compare_values (min, max); + if (cmp == -2 || cmp == 1) + { + /* If the new range has its limits swapped around (MIN > MAX), + then the operation caused one of them to wrap around, mark + the new range VARYING. */ + set_value_range_to_varying (vr); + } + else + set_value_range (vr, vr0.type, min, max, NULL); + return; + } + + /* For unhandled operations fall back to varying. */ + set_value_range_to_varying (vr); + return; +} + + +/* Extract range information from a unary expression CODE OP0 based on + the range of its operand with resulting type TYPE. + The resulting range is stored in *VR. */ + +static void +extract_range_from_unary_expr (value_range_t *vr, enum tree_code code, + tree type, tree op0) +{ + value_range_t vr0 = VR_INITIALIZER; + + /* Get value ranges for the operand. For constant operands, create + a new value range with the operand to simplify processing. */ + if (TREE_CODE (op0) == SSA_NAME) + vr0 = *(get_value_range (op0)); + else if (is_gimple_min_invariant (op0)) + set_value_range_to_value (&vr0, op0, NULL); + else + set_value_range_to_varying (&vr0); + + extract_range_from_unary_expr_1 (vr, code, type, &vr0, TREE_TYPE (op0)); +} + + +/* Extract range information from a conditional expression STMT based on + the ranges of each of its operands and the expression code. */ + +static void +extract_range_from_cond_expr (value_range_t *vr, gimple stmt) +{ + tree op0, op1; + value_range_t vr0 = VR_INITIALIZER; + value_range_t vr1 = VR_INITIALIZER; + + /* Get value ranges for each operand. For constant operands, create + a new value range with the operand to simplify processing. */ + op0 = gimple_assign_rhs2 (stmt); + if (TREE_CODE (op0) == SSA_NAME) + vr0 = *(get_value_range (op0)); + else if (is_gimple_min_invariant (op0)) + set_value_range_to_value (&vr0, op0, NULL); + else + set_value_range_to_varying (&vr0); + + op1 = gimple_assign_rhs3 (stmt); + if (TREE_CODE (op1) == SSA_NAME) + vr1 = *(get_value_range (op1)); + else if (is_gimple_min_invariant (op1)) + set_value_range_to_value (&vr1, op1, NULL); + else + set_value_range_to_varying (&vr1); + + /* The resulting value range is the union of the operand ranges */ + copy_value_range (vr, &vr0); + vrp_meet (vr, &vr1); +} + + +/* Extract range information from a comparison expression EXPR based + on the range of its operand and the expression code. */ + +static void +extract_range_from_comparison (value_range_t *vr, enum tree_code code, + tree type, tree op0, tree op1) +{ + bool sop = false; + tree val; + + val = vrp_evaluate_conditional_warnv_with_ops (code, op0, op1, false, &sop, + NULL); + + /* A disadvantage of using a special infinity as an overflow + representation is that we lose the ability to record overflow + when we don't have an infinity. So we have to ignore a result + which relies on overflow. */ + + if (val && !is_overflow_infinity (val) && !sop) + { + /* Since this expression was found on the RHS of an assignment, + its type may be different from _Bool. Convert VAL to EXPR's + type. */ + val = fold_convert (type, val); + if (is_gimple_min_invariant (val)) + set_value_range_to_value (vr, val, vr->equiv); + else + set_value_range (vr, VR_RANGE, val, val, vr->equiv); + } + else + /* The result of a comparison is always true or false. */ + set_value_range_to_truthvalue (vr, type); +} + +/* Try to derive a nonnegative or nonzero range out of STMT relying + primarily on generic routines in fold in conjunction with range data. + Store the result in *VR */ + +static void +extract_range_basic (value_range_t *vr, gimple stmt) +{ + bool sop = false; + tree type = gimple_expr_type (stmt); + + if (gimple_call_builtin_p (stmt, BUILT_IN_NORMAL)) + { + tree fndecl = gimple_call_fndecl (stmt), arg; + int mini, maxi, zerov = 0, prec; + + switch (DECL_FUNCTION_CODE (fndecl)) + { + case BUILT_IN_CONSTANT_P: + /* If the call is __builtin_constant_p and the argument is a + function parameter resolve it to false. This avoids bogus + array bound warnings. + ??? We could do this as early as inlining is finished. */ + arg = gimple_call_arg (stmt, 0); + if (TREE_CODE (arg) == SSA_NAME + && SSA_NAME_IS_DEFAULT_DEF (arg) + && TREE_CODE (SSA_NAME_VAR (arg)) == PARM_DECL) + { + set_value_range_to_null (vr, type); + return; + } + break; + /* Both __builtin_ffs* and __builtin_popcount return + [0, prec]. */ + CASE_INT_FN (BUILT_IN_FFS): + CASE_INT_FN (BUILT_IN_POPCOUNT): + arg = gimple_call_arg (stmt, 0); + prec = TYPE_PRECISION (TREE_TYPE (arg)); + mini = 0; + maxi = prec; + if (TREE_CODE (arg) == SSA_NAME) + { + value_range_t *vr0 = get_value_range (arg); + /* If arg is non-zero, then ffs or popcount + are non-zero. */ + if (((vr0->type == VR_RANGE + && integer_nonzerop (vr0->min)) + || (vr0->type == VR_ANTI_RANGE + && integer_zerop (vr0->min))) + && !is_overflow_infinity (vr0->min)) + mini = 1; + /* If some high bits are known to be zero, + we can decrease the maximum. */ + if (vr0->type == VR_RANGE + && TREE_CODE (vr0->max) == INTEGER_CST + && !is_overflow_infinity (vr0->max)) + maxi = tree_floor_log2 (vr0->max) + 1; + } + goto bitop_builtin; + /* __builtin_parity* returns [0, 1]. */ + CASE_INT_FN (BUILT_IN_PARITY): + mini = 0; + maxi = 1; + goto bitop_builtin; + /* __builtin_c[lt]z* return [0, prec-1], except for + when the argument is 0, but that is undefined behavior. + On many targets where the CLZ RTL or optab value is defined + for 0 the value is prec, so include that in the range + by default. */ + CASE_INT_FN (BUILT_IN_CLZ): + arg = gimple_call_arg (stmt, 0); + prec = TYPE_PRECISION (TREE_TYPE (arg)); + mini = 0; + maxi = prec; + if (optab_handler (clz_optab, TYPE_MODE (TREE_TYPE (arg))) + != CODE_FOR_nothing + && CLZ_DEFINED_VALUE_AT_ZERO (TYPE_MODE (TREE_TYPE (arg)), + zerov) + /* Handle only the single common value. */ + && zerov != prec) + /* Magic value to give up, unless vr0 proves + arg is non-zero. */ + mini = -2; + if (TREE_CODE (arg) == SSA_NAME) + { + value_range_t *vr0 = get_value_range (arg); + /* From clz of VR_RANGE minimum we can compute + result maximum. */ + if (vr0->type == VR_RANGE + && TREE_CODE (vr0->min) == INTEGER_CST + && !is_overflow_infinity (vr0->min)) + { + maxi = prec - 1 - tree_floor_log2 (vr0->min); + if (maxi != prec) + mini = 0; + } + else if (vr0->type == VR_ANTI_RANGE + && integer_zerop (vr0->min) + && !is_overflow_infinity (vr0->min)) + { + maxi = prec - 1; + mini = 0; + } + if (mini == -2) + break; + /* From clz of VR_RANGE maximum we can compute + result minimum. */ + if (vr0->type == VR_RANGE + && TREE_CODE (vr0->max) == INTEGER_CST + && !is_overflow_infinity (vr0->max)) + { + mini = prec - 1 - tree_floor_log2 (vr0->max); + if (mini == prec) + break; + } + } + if (mini == -2) + break; + goto bitop_builtin; + /* __builtin_ctz* return [0, prec-1], except for + when the argument is 0, but that is undefined behavior. + If there is a ctz optab for this mode and + CTZ_DEFINED_VALUE_AT_ZERO, include that in the range, + otherwise just assume 0 won't be seen. */ + CASE_INT_FN (BUILT_IN_CTZ): + arg = gimple_call_arg (stmt, 0); + prec = TYPE_PRECISION (TREE_TYPE (arg)); + mini = 0; + maxi = prec - 1; + if (optab_handler (ctz_optab, TYPE_MODE (TREE_TYPE (arg))) + != CODE_FOR_nothing + && CTZ_DEFINED_VALUE_AT_ZERO (TYPE_MODE (TREE_TYPE (arg)), + zerov)) + { + /* Handle only the two common values. */ + if (zerov == -1) + mini = -1; + else if (zerov == prec) + maxi = prec; + else + /* Magic value to give up, unless vr0 proves + arg is non-zero. */ + mini = -2; + } + if (TREE_CODE (arg) == SSA_NAME) + { + value_range_t *vr0 = get_value_range (arg); + /* If arg is non-zero, then use [0, prec - 1]. */ + if (((vr0->type == VR_RANGE + && integer_nonzerop (vr0->min)) + || (vr0->type == VR_ANTI_RANGE + && integer_zerop (vr0->min))) + && !is_overflow_infinity (vr0->min)) + { + mini = 0; + maxi = prec - 1; + } + /* If some high bits are known to be zero, + we can decrease the result maximum. */ + if (vr0->type == VR_RANGE + && TREE_CODE (vr0->max) == INTEGER_CST + && !is_overflow_infinity (vr0->max)) + { + maxi = tree_floor_log2 (vr0->max); + /* For vr0 [0, 0] give up. */ + if (maxi == -1) + break; + } + } + if (mini == -2) + break; + goto bitop_builtin; + /* __builtin_clrsb* returns [0, prec-1]. */ + CASE_INT_FN (BUILT_IN_CLRSB): + arg = gimple_call_arg (stmt, 0); + prec = TYPE_PRECISION (TREE_TYPE (arg)); + mini = 0; + maxi = prec - 1; + goto bitop_builtin; + bitop_builtin: + set_value_range (vr, VR_RANGE, build_int_cst (type, mini), + build_int_cst (type, maxi), NULL); + return; + default: + break; + } + } + else if (is_gimple_call (stmt) + && gimple_call_internal_p (stmt)) + { + enum tree_code subcode = ERROR_MARK; + switch (gimple_call_internal_fn (stmt)) + { + case IFN_UBSAN_CHECK_ADD: + subcode = PLUS_EXPR; + break; + case IFN_UBSAN_CHECK_SUB: + subcode = MINUS_EXPR; + break; + case IFN_UBSAN_CHECK_MUL: + subcode = MULT_EXPR; + break; + default: + break; + } + if (subcode != ERROR_MARK) + { + bool saved_flag_wrapv = flag_wrapv; + /* Pretend the arithmetics is wrapping. If there is + any overflow, we'll complain, but will actually do + wrapping operation. */ + flag_wrapv = 1; + extract_range_from_binary_expr (vr, subcode, type, + gimple_call_arg (stmt, 0), + gimple_call_arg (stmt, 1)); + flag_wrapv = saved_flag_wrapv; + + /* If for both arguments vrp_valueize returned non-NULL, + this should have been already folded and if not, it + wasn't folded because of overflow. Avoid removing the + UBSAN_CHECK_* calls in that case. */ + if (vr->type == VR_RANGE + && (vr->min == vr->max + || operand_equal_p (vr->min, vr->max, 0))) + set_value_range_to_varying (vr); + return; + } + } + if (INTEGRAL_TYPE_P (type) + && gimple_stmt_nonnegative_warnv_p (stmt, &sop)) + set_value_range_to_nonnegative (vr, type, + sop || stmt_overflow_infinity (stmt)); + else if (vrp_stmt_computes_nonzero (stmt, &sop) + && !sop) + set_value_range_to_nonnull (vr, type); + else + set_value_range_to_varying (vr); +} + + +/* Try to compute a useful range out of assignment STMT and store it + in *VR. */ + +static void +extract_range_from_assignment (value_range_t *vr, gimple stmt) +{ + enum tree_code code = gimple_assign_rhs_code (stmt); + + if (code == ASSERT_EXPR) + extract_range_from_assert (vr, gimple_assign_rhs1 (stmt)); + else if (code == SSA_NAME) + extract_range_from_ssa_name (vr, gimple_assign_rhs1 (stmt)); + else if (TREE_CODE_CLASS (code) == tcc_binary) + extract_range_from_binary_expr (vr, gimple_assign_rhs_code (stmt), + gimple_expr_type (stmt), + gimple_assign_rhs1 (stmt), + gimple_assign_rhs2 (stmt)); + else if (TREE_CODE_CLASS (code) == tcc_unary) + extract_range_from_unary_expr (vr, gimple_assign_rhs_code (stmt), + gimple_expr_type (stmt), + gimple_assign_rhs1 (stmt)); + else if (code == COND_EXPR) + extract_range_from_cond_expr (vr, stmt); + else if (TREE_CODE_CLASS (code) == tcc_comparison) + extract_range_from_comparison (vr, gimple_assign_rhs_code (stmt), + gimple_expr_type (stmt), + gimple_assign_rhs1 (stmt), + gimple_assign_rhs2 (stmt)); + else if (get_gimple_rhs_class (code) == GIMPLE_SINGLE_RHS + && is_gimple_min_invariant (gimple_assign_rhs1 (stmt))) + set_value_range_to_value (vr, gimple_assign_rhs1 (stmt), NULL); + else + set_value_range_to_varying (vr); + + if (vr->type == VR_VARYING) + extract_range_basic (vr, stmt); +} + +/* Given a range VR, a LOOP and a variable VAR, determine whether it + would be profitable to adjust VR using scalar evolution information + for VAR. If so, update VR with the new limits. */ + +static void +adjust_range_with_scev (value_range_t *vr, struct loop *loop, + gimple stmt, tree var) +{ + tree init, step, chrec, tmin, tmax, min, max, type, tem; + enum ev_direction dir; + + /* TODO. Don't adjust anti-ranges. An anti-range may provide + better opportunities than a regular range, but I'm not sure. */ + if (vr->type == VR_ANTI_RANGE) + return; + + chrec = instantiate_parameters (loop, analyze_scalar_evolution (loop, var)); + + /* Like in PR19590, scev can return a constant function. */ + if (is_gimple_min_invariant (chrec)) + { + set_value_range_to_value (vr, chrec, vr->equiv); + return; + } + + if (TREE_CODE (chrec) != POLYNOMIAL_CHREC) + return; + + init = initial_condition_in_loop_num (chrec, loop->num); + tem = op_with_constant_singleton_value_range (init); + if (tem) + init = tem; + step = evolution_part_in_loop_num (chrec, loop->num); + tem = op_with_constant_singleton_value_range (step); + if (tem) + step = tem; + + /* If STEP is symbolic, we can't know whether INIT will be the + minimum or maximum value in the range. Also, unless INIT is + a simple expression, compare_values and possibly other functions + in tree-vrp won't be able to handle it. */ + if (step == NULL_TREE + || !is_gimple_min_invariant (step) + || !valid_value_p (init)) + return; + + dir = scev_direction (chrec); + if (/* Do not adjust ranges if we do not know whether the iv increases + or decreases, ... */ + dir == EV_DIR_UNKNOWN + /* ... or if it may wrap. */ + || scev_probably_wraps_p (init, step, stmt, get_chrec_loop (chrec), + true)) + return; + + /* We use TYPE_MIN_VALUE and TYPE_MAX_VALUE here instead of + negative_overflow_infinity and positive_overflow_infinity, + because we have concluded that the loop probably does not + wrap. */ + + type = TREE_TYPE (var); + if (POINTER_TYPE_P (type) || !TYPE_MIN_VALUE (type)) + tmin = lower_bound_in_type (type, type); + else + tmin = TYPE_MIN_VALUE (type); + if (POINTER_TYPE_P (type) || !TYPE_MAX_VALUE (type)) + tmax = upper_bound_in_type (type, type); + else + tmax = TYPE_MAX_VALUE (type); + + /* Try to use estimated number of iterations for the loop to constrain the + final value in the evolution. */ + if (TREE_CODE (step) == INTEGER_CST + && is_gimple_val (init) + && (TREE_CODE (init) != SSA_NAME + || get_value_range (init)->type == VR_RANGE)) + { + double_int nit; + + /* We are only entering here for loop header PHI nodes, so using + the number of latch executions is the correct thing to use. */ + if (max_loop_iterations (loop, &nit)) + { + value_range_t maxvr = VR_INITIALIZER; + double_int dtmp; + bool unsigned_p = TYPE_UNSIGNED (TREE_TYPE (step)); + bool overflow = false; + + dtmp = tree_to_double_int (step) + .mul_with_sign (nit, unsigned_p, &overflow); + /* If the multiplication overflowed we can't do a meaningful + adjustment. Likewise if the result doesn't fit in the type + of the induction variable. For a signed type we have to + check whether the result has the expected signedness which + is that of the step as number of iterations is unsigned. */ + if (!overflow + && double_int_fits_to_tree_p (TREE_TYPE (init), dtmp) + && (unsigned_p + || ((dtmp.high ^ TREE_INT_CST_HIGH (step)) >= 0))) + { + tem = double_int_to_tree (TREE_TYPE (init), dtmp); + extract_range_from_binary_expr (&maxvr, PLUS_EXPR, + TREE_TYPE (init), init, tem); + /* Likewise if the addition did. */ + if (maxvr.type == VR_RANGE) + { + tmin = maxvr.min; + tmax = maxvr.max; + } + } + } + } + + if (vr->type == VR_VARYING || vr->type == VR_UNDEFINED) + { + min = tmin; + max = tmax; + + /* For VARYING or UNDEFINED ranges, just about anything we get + from scalar evolutions should be better. */ + + if (dir == EV_DIR_DECREASES) + max = init; + else + min = init; + + /* If we would create an invalid range, then just assume we + know absolutely nothing. This may be over-conservative, + but it's clearly safe, and should happen only in unreachable + parts of code, or for invalid programs. */ + if (compare_values (min, max) == 1) + return; + + set_value_range (vr, VR_RANGE, min, max, vr->equiv); + } + else if (vr->type == VR_RANGE) + { + min = vr->min; + max = vr->max; + + if (dir == EV_DIR_DECREASES) + { + /* INIT is the maximum value. If INIT is lower than VR->MAX + but no smaller than VR->MIN, set VR->MAX to INIT. */ + if (compare_values (init, max) == -1) + max = init; + + /* According to the loop information, the variable does not + overflow. If we think it does, probably because of an + overflow due to arithmetic on a different INF value, + reset now. */ + if (is_negative_overflow_infinity (min) + || compare_values (min, tmin) == -1) + min = tmin; + + } + else + { + /* If INIT is bigger than VR->MIN, set VR->MIN to INIT. */ + if (compare_values (init, min) == 1) + min = init; + + if (is_positive_overflow_infinity (max) + || compare_values (tmax, max) == -1) + max = tmax; + } + + /* If we just created an invalid range with the minimum + greater than the maximum, we fail conservatively. + This should happen only in unreachable + parts of code, or for invalid programs. */ + if (compare_values (min, max) == 1) + return; + + set_value_range (vr, VR_RANGE, min, max, vr->equiv); + } +} + +/* Return true if VAR may overflow at STMT. This checks any available + loop information to see if we can determine that VAR does not + overflow. */ + +static bool +vrp_var_may_overflow (tree var, gimple stmt) +{ + struct loop *l; + tree chrec, init, step; + + if (current_loops == NULL) + return true; + + l = loop_containing_stmt (stmt); + if (l == NULL + || !loop_outer (l)) + return true; + + chrec = instantiate_parameters (l, analyze_scalar_evolution (l, var)); + if (TREE_CODE (chrec) != POLYNOMIAL_CHREC) + return true; + + init = initial_condition_in_loop_num (chrec, l->num); + step = evolution_part_in_loop_num (chrec, l->num); + + if (step == NULL_TREE + || !is_gimple_min_invariant (step) + || !valid_value_p (init)) + return true; + + /* If we get here, we know something useful about VAR based on the + loop information. If it wraps, it may overflow. */ + + if (scev_probably_wraps_p (init, step, stmt, get_chrec_loop (chrec), + true)) + return true; + + if (dump_file && (dump_flags & TDF_DETAILS) != 0) + { + print_generic_expr (dump_file, var, 0); + fprintf (dump_file, ": loop information indicates does not overflow\n"); + } + + return false; +} + + +/* Given two numeric value ranges VR0, VR1 and a comparison code COMP: + + - Return BOOLEAN_TRUE_NODE if VR0 COMP VR1 always returns true for + all the values in the ranges. + + - Return BOOLEAN_FALSE_NODE if the comparison always returns false. + + - Return NULL_TREE if it is not always possible to determine the + value of the comparison. + + Also set *STRICT_OVERFLOW_P to indicate whether a range with an + overflow infinity was used in the test. */ + + +static tree +compare_ranges (enum tree_code comp, value_range_t *vr0, value_range_t *vr1, + bool *strict_overflow_p) +{ + /* VARYING or UNDEFINED ranges cannot be compared. */ + if (vr0->type == VR_VARYING + || vr0->type == VR_UNDEFINED + || vr1->type == VR_VARYING + || vr1->type == VR_UNDEFINED) + return NULL_TREE; + + /* Anti-ranges need to be handled separately. */ + if (vr0->type == VR_ANTI_RANGE || vr1->type == VR_ANTI_RANGE) + { + /* If both are anti-ranges, then we cannot compute any + comparison. */ + if (vr0->type == VR_ANTI_RANGE && vr1->type == VR_ANTI_RANGE) + return NULL_TREE; + + /* These comparisons are never statically computable. */ + if (comp == GT_EXPR + || comp == GE_EXPR + || comp == LT_EXPR + || comp == LE_EXPR) + return NULL_TREE; + + /* Equality can be computed only between a range and an + anti-range. ~[VAL1, VAL2] == [VAL1, VAL2] is always false. */ + if (vr0->type == VR_RANGE) + { + /* To simplify processing, make VR0 the anti-range. */ + value_range_t *tmp = vr0; + vr0 = vr1; + vr1 = tmp; + } + + gcc_assert (comp == NE_EXPR || comp == EQ_EXPR); + + if (compare_values_warnv (vr0->min, vr1->min, strict_overflow_p) == 0 + && compare_values_warnv (vr0->max, vr1->max, strict_overflow_p) == 0) + return (comp == NE_EXPR) ? boolean_true_node : boolean_false_node; + + return NULL_TREE; + } + + if (!usable_range_p (vr0, strict_overflow_p) + || !usable_range_p (vr1, strict_overflow_p)) + return NULL_TREE; + + /* Simplify processing. If COMP is GT_EXPR or GE_EXPR, switch the + operands around and change the comparison code. */ + if (comp == GT_EXPR || comp == GE_EXPR) + { + value_range_t *tmp; + comp = (comp == GT_EXPR) ? LT_EXPR : LE_EXPR; + tmp = vr0; + vr0 = vr1; + vr1 = tmp; + } + + if (comp == EQ_EXPR) + { + /* Equality may only be computed if both ranges represent + exactly one value. */ + if (compare_values_warnv (vr0->min, vr0->max, strict_overflow_p) == 0 + && compare_values_warnv (vr1->min, vr1->max, strict_overflow_p) == 0) + { + int cmp_min = compare_values_warnv (vr0->min, vr1->min, + strict_overflow_p); + int cmp_max = compare_values_warnv (vr0->max, vr1->max, + strict_overflow_p); + if (cmp_min == 0 && cmp_max == 0) + return boolean_true_node; + else if (cmp_min != -2 && cmp_max != -2) + return boolean_false_node; + } + /* If [V0_MIN, V1_MAX] < [V1_MIN, V1_MAX] then V0 != V1. */ + else if (compare_values_warnv (vr0->min, vr1->max, + strict_overflow_p) == 1 + || compare_values_warnv (vr1->min, vr0->max, + strict_overflow_p) == 1) + return boolean_false_node; + + return NULL_TREE; + } + else if (comp == NE_EXPR) + { + int cmp1, cmp2; + + /* If VR0 is completely to the left or completely to the right + of VR1, they are always different. Notice that we need to + make sure that both comparisons yield similar results to + avoid comparing values that cannot be compared at + compile-time. */ + cmp1 = compare_values_warnv (vr0->max, vr1->min, strict_overflow_p); + cmp2 = compare_values_warnv (vr0->min, vr1->max, strict_overflow_p); + if ((cmp1 == -1 && cmp2 == -1) || (cmp1 == 1 && cmp2 == 1)) + return boolean_true_node; + + /* If VR0 and VR1 represent a single value and are identical, + return false. */ + else if (compare_values_warnv (vr0->min, vr0->max, + strict_overflow_p) == 0 + && compare_values_warnv (vr1->min, vr1->max, + strict_overflow_p) == 0 + && compare_values_warnv (vr0->min, vr1->min, + strict_overflow_p) == 0 + && compare_values_warnv (vr0->max, vr1->max, + strict_overflow_p) == 0) + return boolean_false_node; + + /* Otherwise, they may or may not be different. */ + else + return NULL_TREE; + } + else if (comp == LT_EXPR || comp == LE_EXPR) + { + int tst; + + /* If VR0 is to the left of VR1, return true. */ + tst = compare_values_warnv (vr0->max, vr1->min, strict_overflow_p); + if ((comp == LT_EXPR && tst == -1) + || (comp == LE_EXPR && (tst == -1 || tst == 0))) + { + if (overflow_infinity_range_p (vr0) + || overflow_infinity_range_p (vr1)) + *strict_overflow_p = true; + return boolean_true_node; + } + + /* If VR0 is to the right of VR1, return false. */ + tst = compare_values_warnv (vr0->min, vr1->max, strict_overflow_p); + if ((comp == LT_EXPR && (tst == 0 || tst == 1)) + || (comp == LE_EXPR && tst == 1)) + { + if (overflow_infinity_range_p (vr0) + || overflow_infinity_range_p (vr1)) + *strict_overflow_p = true; + return boolean_false_node; + } + + /* Otherwise, we don't know. */ + return NULL_TREE; + } + + gcc_unreachable (); +} + + +/* Given a value range VR, a value VAL and a comparison code COMP, return + BOOLEAN_TRUE_NODE if VR COMP VAL always returns true for all the + values in VR. Return BOOLEAN_FALSE_NODE if the comparison + always returns false. Return NULL_TREE if it is not always + possible to determine the value of the comparison. Also set + *STRICT_OVERFLOW_P to indicate whether a range with an overflow + infinity was used in the test. */ + +static tree +compare_range_with_value (enum tree_code comp, value_range_t *vr, tree val, + bool *strict_overflow_p) +{ + if (vr->type == VR_VARYING || vr->type == VR_UNDEFINED) + return NULL_TREE; + + /* Anti-ranges need to be handled separately. */ + if (vr->type == VR_ANTI_RANGE) + { + /* For anti-ranges, the only predicates that we can compute at + compile time are equality and inequality. */ + if (comp == GT_EXPR + || comp == GE_EXPR + || comp == LT_EXPR + || comp == LE_EXPR) + return NULL_TREE; + + /* ~[VAL_1, VAL_2] OP VAL is known if VAL_1 <= VAL <= VAL_2. */ + if (value_inside_range (val, vr->min, vr->max) == 1) + return (comp == NE_EXPR) ? boolean_true_node : boolean_false_node; + + return NULL_TREE; + } + + if (!usable_range_p (vr, strict_overflow_p)) + return NULL_TREE; + + if (comp == EQ_EXPR) + { + /* EQ_EXPR may only be computed if VR represents exactly + one value. */ + if (compare_values_warnv (vr->min, vr->max, strict_overflow_p) == 0) + { + int cmp = compare_values_warnv (vr->min, val, strict_overflow_p); + if (cmp == 0) + return boolean_true_node; + else if (cmp == -1 || cmp == 1 || cmp == 2) + return boolean_false_node; + } + else if (compare_values_warnv (val, vr->min, strict_overflow_p) == -1 + || compare_values_warnv (vr->max, val, strict_overflow_p) == -1) + return boolean_false_node; + + return NULL_TREE; + } + else if (comp == NE_EXPR) + { + /* If VAL is not inside VR, then they are always different. */ + if (compare_values_warnv (vr->max, val, strict_overflow_p) == -1 + || compare_values_warnv (vr->min, val, strict_overflow_p) == 1) + return boolean_true_node; + + /* If VR represents exactly one value equal to VAL, then return + false. */ + if (compare_values_warnv (vr->min, vr->max, strict_overflow_p) == 0 + && compare_values_warnv (vr->min, val, strict_overflow_p) == 0) + return boolean_false_node; + + /* Otherwise, they may or may not be different. */ + return NULL_TREE; + } + else if (comp == LT_EXPR || comp == LE_EXPR) + { + int tst; + + /* If VR is to the left of VAL, return true. */ + tst = compare_values_warnv (vr->max, val, strict_overflow_p); + if ((comp == LT_EXPR && tst == -1) + || (comp == LE_EXPR && (tst == -1 || tst == 0))) + { + if (overflow_infinity_range_p (vr)) + *strict_overflow_p = true; + return boolean_true_node; + } + + /* If VR is to the right of VAL, return false. */ + tst = compare_values_warnv (vr->min, val, strict_overflow_p); + if ((comp == LT_EXPR && (tst == 0 || tst == 1)) + || (comp == LE_EXPR && tst == 1)) + { + if (overflow_infinity_range_p (vr)) + *strict_overflow_p = true; + return boolean_false_node; + } + + /* Otherwise, we don't know. */ + return NULL_TREE; + } + else if (comp == GT_EXPR || comp == GE_EXPR) + { + int tst; + + /* If VR is to the right of VAL, return true. */ + tst = compare_values_warnv (vr->min, val, strict_overflow_p); + if ((comp == GT_EXPR && tst == 1) + || (comp == GE_EXPR && (tst == 0 || tst == 1))) + { + if (overflow_infinity_range_p (vr)) + *strict_overflow_p = true; + return boolean_true_node; + } + + /* If VR is to the left of VAL, return false. */ + tst = compare_values_warnv (vr->max, val, strict_overflow_p); + if ((comp == GT_EXPR && (tst == -1 || tst == 0)) + || (comp == GE_EXPR && tst == -1)) + { + if (overflow_infinity_range_p (vr)) + *strict_overflow_p = true; + return boolean_false_node; + } + + /* Otherwise, we don't know. */ + return NULL_TREE; + } + + gcc_unreachable (); +} + + +/* Debugging dumps. */ + +void dump_value_range (FILE *, value_range_t *); +void debug_value_range (value_range_t *); +void dump_all_value_ranges (FILE *); +void debug_all_value_ranges (void); +void dump_vr_equiv (FILE *, bitmap); +void debug_vr_equiv (bitmap); + + +/* Dump value range VR to FILE. */ + +void +dump_value_range (FILE *file, value_range_t *vr) +{ + if (vr == NULL) + fprintf (file, "[]"); + else if (vr->type == VR_UNDEFINED) + fprintf (file, "UNDEFINED"); + else if (vr->type == VR_RANGE || vr->type == VR_ANTI_RANGE) + { + tree type = TREE_TYPE (vr->min); + + fprintf (file, "%s[", (vr->type == VR_ANTI_RANGE) ? "~" : ""); + + if (is_negative_overflow_infinity (vr->min)) + fprintf (file, "-INF(OVF)"); + else if (INTEGRAL_TYPE_P (type) + && !TYPE_UNSIGNED (type) + && vrp_val_is_min (vr->min)) + fprintf (file, "-INF"); + else + print_generic_expr (file, vr->min, 0); + + fprintf (file, ", "); + + if (is_positive_overflow_infinity (vr->max)) + fprintf (file, "+INF(OVF)"); + else if (INTEGRAL_TYPE_P (type) + && vrp_val_is_max (vr->max)) + fprintf (file, "+INF"); + else + print_generic_expr (file, vr->max, 0); + + fprintf (file, "]"); + + if (vr->equiv) + { + bitmap_iterator bi; + unsigned i, c = 0; + + fprintf (file, " EQUIVALENCES: { "); + + EXECUTE_IF_SET_IN_BITMAP (vr->equiv, 0, i, bi) + { + print_generic_expr (file, ssa_name (i), 0); + fprintf (file, " "); + c++; + } + + fprintf (file, "} (%u elements)", c); + } + } + else if (vr->type == VR_VARYING) + fprintf (file, "VARYING"); + else + fprintf (file, "INVALID RANGE"); +} + + +/* Dump value range VR to stderr. */ + +DEBUG_FUNCTION void +debug_value_range (value_range_t *vr) +{ + dump_value_range (stderr, vr); + fprintf (stderr, "\n"); +} + + +/* Dump value ranges of all SSA_NAMEs to FILE. */ + +void +dump_all_value_ranges (FILE *file) +{ + size_t i; + + for (i = 0; i < num_vr_values; i++) + { + if (vr_value[i]) + { + print_generic_expr (file, ssa_name (i), 0); + fprintf (file, ": "); + dump_value_range (file, vr_value[i]); + fprintf (file, "\n"); + } + } + + fprintf (file, "\n"); +} + + +/* Dump all value ranges to stderr. */ + +DEBUG_FUNCTION void +debug_all_value_ranges (void) +{ + dump_all_value_ranges (stderr); +} + + +/* Given a COND_EXPR COND of the form 'V OP W', and an SSA name V, + create a new SSA name N and return the assertion assignment + 'V = ASSERT_EXPR <V, V OP W>'. */ + +static gimple +build_assert_expr_for (tree cond, tree v) +{ + tree a; + gimple assertion; + + gcc_assert (TREE_CODE (v) == SSA_NAME + && COMPARISON_CLASS_P (cond)); + + a = build2 (ASSERT_EXPR, TREE_TYPE (v), v, cond); + assertion = gimple_build_assign (NULL_TREE, a); + + /* The new ASSERT_EXPR, creates a new SSA name that replaces the + operand of the ASSERT_EXPR. Create it so the new name and the old one + are registered in the replacement table so that we can fix the SSA web + after adding all the ASSERT_EXPRs. */ + create_new_def_for (v, assertion, NULL); + + return assertion; +} + + +/* Return false if EXPR is a predicate expression involving floating + point values. */ + +static inline bool +fp_predicate (gimple stmt) +{ + GIMPLE_CHECK (stmt, GIMPLE_COND); + + return FLOAT_TYPE_P (TREE_TYPE (gimple_cond_lhs (stmt))); +} + +/* If the range of values taken by OP can be inferred after STMT executes, + return the comparison code (COMP_CODE_P) and value (VAL_P) that + describes the inferred range. Return true if a range could be + inferred. */ + +static bool +infer_value_range (gimple stmt, tree op, enum tree_code *comp_code_p, tree *val_p) +{ + *val_p = NULL_TREE; + *comp_code_p = ERROR_MARK; + + /* Do not attempt to infer anything in names that flow through + abnormal edges. */ + if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (op)) + return false; + + /* Similarly, don't infer anything from statements that may throw + exceptions. ??? Relax this requirement? */ + if (stmt_could_throw_p (stmt)) + return false; + + /* If STMT is the last statement of a basic block with no normal + successors, there is no point inferring anything about any of its + operands. We would not be able to find a proper insertion point + for the assertion, anyway. */ + if (stmt_ends_bb_p (stmt)) + { + edge_iterator ei; + edge e; + + FOR_EACH_EDGE (e, ei, gimple_bb (stmt)->succs) + if (!(e->flags & EDGE_ABNORMAL)) + break; + if (e == NULL) + return false; + } + + if (infer_nonnull_range (stmt, op, true, true)) + { + *val_p = build_int_cst (TREE_TYPE (op), 0); + *comp_code_p = NE_EXPR; + return true; + } + + return false; +} + + +void dump_asserts_for (FILE *, tree); +void debug_asserts_for (tree); +void dump_all_asserts (FILE *); +void debug_all_asserts (void); + +/* Dump all the registered assertions for NAME to FILE. */ + +void +dump_asserts_for (FILE *file, tree name) +{ + assert_locus_t loc; + + fprintf (file, "Assertions to be inserted for "); + print_generic_expr (file, name, 0); + fprintf (file, "\n"); + + loc = asserts_for[SSA_NAME_VERSION (name)]; + while (loc) + { + fprintf (file, "\t"); + print_gimple_stmt (file, gsi_stmt (loc->si), 0, 0); + fprintf (file, "\n\tBB #%d", loc->bb->index); + if (loc->e) + { + fprintf (file, "\n\tEDGE %d->%d", loc->e->src->index, + loc->e->dest->index); + dump_edge_info (file, loc->e, dump_flags, 0); + } + fprintf (file, "\n\tPREDICATE: "); + print_generic_expr (file, name, 0); + fprintf (file, " %s ", get_tree_code_name (loc->comp_code)); + print_generic_expr (file, loc->val, 0); + fprintf (file, "\n\n"); + loc = loc->next; + } + + fprintf (file, "\n"); +} + + +/* Dump all the registered assertions for NAME to stderr. */ + +DEBUG_FUNCTION void +debug_asserts_for (tree name) +{ + dump_asserts_for (stderr, name); +} + + +/* Dump all the registered assertions for all the names to FILE. */ + +void +dump_all_asserts (FILE *file) +{ + unsigned i; + bitmap_iterator bi; + + fprintf (file, "\nASSERT_EXPRs to be inserted\n\n"); + EXECUTE_IF_SET_IN_BITMAP (need_assert_for, 0, i, bi) + dump_asserts_for (file, ssa_name (i)); + fprintf (file, "\n"); +} + + +/* Dump all the registered assertions for all the names to stderr. */ + +DEBUG_FUNCTION void +debug_all_asserts (void) +{ + dump_all_asserts (stderr); +} + + +/* If NAME doesn't have an ASSERT_EXPR registered for asserting + 'EXPR COMP_CODE VAL' at a location that dominates block BB or + E->DEST, then register this location as a possible insertion point + for ASSERT_EXPR <NAME, EXPR COMP_CODE VAL>. + + BB, E and SI provide the exact insertion point for the new + ASSERT_EXPR. If BB is NULL, then the ASSERT_EXPR is to be inserted + on edge E. Otherwise, if E is NULL, the ASSERT_EXPR is inserted on + BB. If SI points to a COND_EXPR or a SWITCH_EXPR statement, then E + must not be NULL. */ + +static void +register_new_assert_for (tree name, tree expr, + enum tree_code comp_code, + tree val, + basic_block bb, + edge e, + gimple_stmt_iterator si) +{ + assert_locus_t n, loc, last_loc; + basic_block dest_bb; + + gcc_checking_assert (bb == NULL || e == NULL); + + if (e == NULL) + gcc_checking_assert (gimple_code (gsi_stmt (si)) != GIMPLE_COND + && gimple_code (gsi_stmt (si)) != GIMPLE_SWITCH); + + /* Never build an assert comparing against an integer constant with + TREE_OVERFLOW set. This confuses our undefined overflow warning + machinery. */ + if (TREE_OVERFLOW_P (val)) + val = drop_tree_overflow (val); + + /* The new assertion A will be inserted at BB or E. We need to + determine if the new location is dominated by a previously + registered location for A. If we are doing an edge insertion, + assume that A will be inserted at E->DEST. Note that this is not + necessarily true. + + If E is a critical edge, it will be split. But even if E is + split, the new block will dominate the same set of blocks that + E->DEST dominates. + + The reverse, however, is not true, blocks dominated by E->DEST + will not be dominated by the new block created to split E. So, + if the insertion location is on a critical edge, we will not use + the new location to move another assertion previously registered + at a block dominated by E->DEST. */ + dest_bb = (bb) ? bb : e->dest; + + /* If NAME already has an ASSERT_EXPR registered for COMP_CODE and + VAL at a block dominating DEST_BB, then we don't need to insert a new + one. Similarly, if the same assertion already exists at a block + dominated by DEST_BB and the new location is not on a critical + edge, then update the existing location for the assertion (i.e., + move the assertion up in the dominance tree). + + Note, this is implemented as a simple linked list because there + should not be more than a handful of assertions registered per + name. If this becomes a performance problem, a table hashed by + COMP_CODE and VAL could be implemented. */ + loc = asserts_for[SSA_NAME_VERSION (name)]; + last_loc = loc; + while (loc) + { + if (loc->comp_code == comp_code + && (loc->val == val + || operand_equal_p (loc->val, val, 0)) + && (loc->expr == expr + || operand_equal_p (loc->expr, expr, 0))) + { + /* If E is not a critical edge and DEST_BB + dominates the existing location for the assertion, move + the assertion up in the dominance tree by updating its + location information. */ + if ((e == NULL || !EDGE_CRITICAL_P (e)) + && dominated_by_p (CDI_DOMINATORS, loc->bb, dest_bb)) + { + loc->bb = dest_bb; + loc->e = e; + loc->si = si; + return; + } + } + + /* Update the last node of the list and move to the next one. */ + last_loc = loc; + loc = loc->next; + } + + /* If we didn't find an assertion already registered for + NAME COMP_CODE VAL, add a new one at the end of the list of + assertions associated with NAME. */ + n = XNEW (struct assert_locus_d); + n->bb = dest_bb; + n->e = e; + n->si = si; + n->comp_code = comp_code; + n->val = val; + n->expr = expr; + n->next = NULL; + + if (last_loc) + last_loc->next = n; + else + asserts_for[SSA_NAME_VERSION (name)] = n; + + bitmap_set_bit (need_assert_for, SSA_NAME_VERSION (name)); +} + +/* (COND_OP0 COND_CODE COND_OP1) is a predicate which uses NAME. + Extract a suitable test code and value and store them into *CODE_P and + *VAL_P so the predicate is normalized to NAME *CODE_P *VAL_P. + + If no extraction was possible, return FALSE, otherwise return TRUE. + + If INVERT is true, then we invert the result stored into *CODE_P. */ + +static bool +extract_code_and_val_from_cond_with_ops (tree name, enum tree_code cond_code, + tree cond_op0, tree cond_op1, + bool invert, enum tree_code *code_p, + tree *val_p) +{ + enum tree_code comp_code; + tree val; + + /* Otherwise, we have a comparison of the form NAME COMP VAL + or VAL COMP NAME. */ + if (name == cond_op1) + { + /* If the predicate is of the form VAL COMP NAME, flip + COMP around because we need to register NAME as the + first operand in the predicate. */ + comp_code = swap_tree_comparison (cond_code); + val = cond_op0; + } + else + { + /* The comparison is of the form NAME COMP VAL, so the + comparison code remains unchanged. */ + comp_code = cond_code; + val = cond_op1; + } + + /* Invert the comparison code as necessary. */ + if (invert) + comp_code = invert_tree_comparison (comp_code, 0); + + /* VRP does not handle float types. */ + if (SCALAR_FLOAT_TYPE_P (TREE_TYPE (val))) + return false; + + /* Do not register always-false predicates. + FIXME: this works around a limitation in fold() when dealing with + enumerations. Given 'enum { N1, N2 } x;', fold will not + fold 'if (x > N2)' to 'if (0)'. */ + if ((comp_code == GT_EXPR || comp_code == LT_EXPR) + && INTEGRAL_TYPE_P (TREE_TYPE (val))) + { + tree min = TYPE_MIN_VALUE (TREE_TYPE (val)); + tree max = TYPE_MAX_VALUE (TREE_TYPE (val)); + + if (comp_code == GT_EXPR + && (!max + || compare_values (val, max) == 0)) + return false; + + if (comp_code == LT_EXPR + && (!min + || compare_values (val, min) == 0)) + return false; + } + *code_p = comp_code; + *val_p = val; + return true; +} + +/* Find out smallest RES where RES > VAL && (RES & MASK) == RES, if any + (otherwise return VAL). VAL and MASK must be zero-extended for + precision PREC. If SGNBIT is non-zero, first xor VAL with SGNBIT + (to transform signed values into unsigned) and at the end xor + SGNBIT back. */ + +static double_int +masked_increment (double_int val, double_int mask, double_int sgnbit, + unsigned int prec) +{ + double_int bit = double_int_one, res; + unsigned int i; + + val ^= sgnbit; + for (i = 0; i < prec; i++, bit += bit) + { + res = mask; + if ((res & bit).is_zero ()) + continue; + res = bit - double_int_one; + res = (val + bit).and_not (res); + res &= mask; + if (res.ugt (val)) + return res ^ sgnbit; + } + return val ^ sgnbit; +} + +/* Try to register an edge assertion for SSA name NAME on edge E for + the condition COND contributing to the conditional jump pointed to by BSI. + Invert the condition COND if INVERT is true. + Return true if an assertion for NAME could be registered. */ + +static bool +register_edge_assert_for_2 (tree name, edge e, gimple_stmt_iterator bsi, + enum tree_code cond_code, + tree cond_op0, tree cond_op1, bool invert) +{ + tree val; + enum tree_code comp_code; + bool retval = false; + + if (!extract_code_and_val_from_cond_with_ops (name, cond_code, + cond_op0, + cond_op1, + invert, &comp_code, &val)) + return false; + + /* Only register an ASSERT_EXPR if NAME was found in the sub-graph + reachable from E. */ + if (live_on_edge (e, name) + && !has_single_use (name)) + { + register_new_assert_for (name, name, comp_code, val, NULL, e, bsi); + retval = true; + } + + /* In the case of NAME <= CST and NAME being defined as + NAME = (unsigned) NAME2 + CST2 we can assert NAME2 >= -CST2 + and NAME2 <= CST - CST2. We can do the same for NAME > CST. + This catches range and anti-range tests. */ + if ((comp_code == LE_EXPR + || comp_code == GT_EXPR) + && TREE_CODE (val) == INTEGER_CST + && TYPE_UNSIGNED (TREE_TYPE (val))) + { + gimple def_stmt = SSA_NAME_DEF_STMT (name); + tree cst2 = NULL_TREE, name2 = NULL_TREE, name3 = NULL_TREE; + + /* Extract CST2 from the (optional) addition. */ + if (is_gimple_assign (def_stmt) + && gimple_assign_rhs_code (def_stmt) == PLUS_EXPR) + { + name2 = gimple_assign_rhs1 (def_stmt); + cst2 = gimple_assign_rhs2 (def_stmt); + if (TREE_CODE (name2) == SSA_NAME + && TREE_CODE (cst2) == INTEGER_CST) + def_stmt = SSA_NAME_DEF_STMT (name2); + } + + /* Extract NAME2 from the (optional) sign-changing cast. */ + if (gimple_assign_cast_p (def_stmt)) + { + if (CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (def_stmt)) + && ! TYPE_UNSIGNED (TREE_TYPE (gimple_assign_rhs1 (def_stmt))) + && (TYPE_PRECISION (gimple_expr_type (def_stmt)) + == TYPE_PRECISION (TREE_TYPE (gimple_assign_rhs1 (def_stmt))))) + name3 = gimple_assign_rhs1 (def_stmt); + } + + /* If name3 is used later, create an ASSERT_EXPR for it. */ + if (name3 != NULL_TREE + && TREE_CODE (name3) == SSA_NAME + && (cst2 == NULL_TREE + || TREE_CODE (cst2) == INTEGER_CST) + && INTEGRAL_TYPE_P (TREE_TYPE (name3)) + && live_on_edge (e, name3) + && !has_single_use (name3)) + { + tree tmp; + + /* Build an expression for the range test. */ + tmp = build1 (NOP_EXPR, TREE_TYPE (name), name3); + if (cst2 != NULL_TREE) + tmp = build2 (PLUS_EXPR, TREE_TYPE (name), tmp, cst2); + + if (dump_file) + { + fprintf (dump_file, "Adding assert for "); + print_generic_expr (dump_file, name3, 0); + fprintf (dump_file, " from "); + print_generic_expr (dump_file, tmp, 0); + fprintf (dump_file, "\n"); + } + + register_new_assert_for (name3, tmp, comp_code, val, NULL, e, bsi); + + retval = true; + } + + /* If name2 is used later, create an ASSERT_EXPR for it. */ + if (name2 != NULL_TREE + && TREE_CODE (name2) == SSA_NAME + && TREE_CODE (cst2) == INTEGER_CST + && INTEGRAL_TYPE_P (TREE_TYPE (name2)) + && live_on_edge (e, name2) + && !has_single_use (name2)) + { + tree tmp; + + /* Build an expression for the range test. */ + tmp = name2; + if (TREE_TYPE (name) != TREE_TYPE (name2)) + tmp = build1 (NOP_EXPR, TREE_TYPE (name), tmp); + if (cst2 != NULL_TREE) + tmp = build2 (PLUS_EXPR, TREE_TYPE (name), tmp, cst2); + + if (dump_file) + { + fprintf (dump_file, "Adding assert for "); + print_generic_expr (dump_file, name2, 0); + fprintf (dump_file, " from "); + print_generic_expr (dump_file, tmp, 0); + fprintf (dump_file, "\n"); + } + + register_new_assert_for (name2, tmp, comp_code, val, NULL, e, bsi); + + retval = true; + } + } + + /* In the case of post-in/decrement tests like if (i++) ... and uses + of the in/decremented value on the edge the extra name we want to + assert for is not on the def chain of the name compared. Instead + it is in the set of use stmts. */ + if ((comp_code == NE_EXPR + || comp_code == EQ_EXPR) + && TREE_CODE (val) == INTEGER_CST) + { + imm_use_iterator ui; + gimple use_stmt; + FOR_EACH_IMM_USE_STMT (use_stmt, ui, name) + { + /* Cut off to use-stmts that are in the predecessor. */ + if (gimple_bb (use_stmt) != e->src) + continue; + + if (!is_gimple_assign (use_stmt)) + continue; + + enum tree_code code = gimple_assign_rhs_code (use_stmt); + if (code != PLUS_EXPR + && code != MINUS_EXPR) + continue; + + tree cst = gimple_assign_rhs2 (use_stmt); + if (TREE_CODE (cst) != INTEGER_CST) + continue; + + tree name2 = gimple_assign_lhs (use_stmt); + if (live_on_edge (e, name2)) + { + cst = int_const_binop (code, val, cst); + register_new_assert_for (name2, name2, comp_code, cst, + NULL, e, bsi); + retval = true; + } + } + } + + if (TREE_CODE_CLASS (comp_code) == tcc_comparison + && TREE_CODE (val) == INTEGER_CST) + { + gimple def_stmt = SSA_NAME_DEF_STMT (name); + tree name2 = NULL_TREE, names[2], cst2 = NULL_TREE; + tree val2 = NULL_TREE; + double_int mask = double_int_zero; + unsigned int prec = TYPE_PRECISION (TREE_TYPE (val)); + unsigned int nprec = prec; + enum tree_code rhs_code = ERROR_MARK; + + if (is_gimple_assign (def_stmt)) + rhs_code = gimple_assign_rhs_code (def_stmt); + + /* Add asserts for NAME cmp CST and NAME being defined + as NAME = (int) NAME2. */ + if (!TYPE_UNSIGNED (TREE_TYPE (val)) + && (comp_code == LE_EXPR || comp_code == LT_EXPR + || comp_code == GT_EXPR || comp_code == GE_EXPR) + && gimple_assign_cast_p (def_stmt)) + { + name2 = gimple_assign_rhs1 (def_stmt); + if (CONVERT_EXPR_CODE_P (rhs_code) + && INTEGRAL_TYPE_P (TREE_TYPE (name2)) + && TYPE_UNSIGNED (TREE_TYPE (name2)) + && prec == TYPE_PRECISION (TREE_TYPE (name2)) + && (comp_code == LE_EXPR || comp_code == GT_EXPR + || !tree_int_cst_equal (val, + TYPE_MIN_VALUE (TREE_TYPE (val)))) + && live_on_edge (e, name2) + && !has_single_use (name2)) + { + tree tmp, cst; + enum tree_code new_comp_code = comp_code; + + cst = fold_convert (TREE_TYPE (name2), + TYPE_MIN_VALUE (TREE_TYPE (val))); + /* Build an expression for the range test. */ + tmp = build2 (PLUS_EXPR, TREE_TYPE (name2), name2, cst); + cst = fold_build2 (PLUS_EXPR, TREE_TYPE (name2), cst, + fold_convert (TREE_TYPE (name2), val)); + if (comp_code == LT_EXPR || comp_code == GE_EXPR) + { + new_comp_code = comp_code == LT_EXPR ? LE_EXPR : GT_EXPR; + cst = fold_build2 (MINUS_EXPR, TREE_TYPE (name2), cst, + build_int_cst (TREE_TYPE (name2), 1)); + } + + if (dump_file) + { + fprintf (dump_file, "Adding assert for "); + print_generic_expr (dump_file, name2, 0); + fprintf (dump_file, " from "); + print_generic_expr (dump_file, tmp, 0); + fprintf (dump_file, "\n"); + } + + register_new_assert_for (name2, tmp, new_comp_code, cst, NULL, + e, bsi); + + retval = true; + } + } + + /* Add asserts for NAME cmp CST and NAME being defined as + NAME = NAME2 >> CST2. + + Extract CST2 from the right shift. */ + if (rhs_code == RSHIFT_EXPR) + { + name2 = gimple_assign_rhs1 (def_stmt); + cst2 = gimple_assign_rhs2 (def_stmt); + if (TREE_CODE (name2) == SSA_NAME + && tree_fits_uhwi_p (cst2) + && INTEGRAL_TYPE_P (TREE_TYPE (name2)) + && IN_RANGE (tree_to_uhwi (cst2), 1, prec - 1) + && prec <= HOST_BITS_PER_DOUBLE_INT + && prec == GET_MODE_PRECISION (TYPE_MODE (TREE_TYPE (val))) + && live_on_edge (e, name2) + && !has_single_use (name2)) + { + mask = double_int::mask (tree_to_uhwi (cst2)); + val2 = fold_binary (LSHIFT_EXPR, TREE_TYPE (val), val, cst2); + } + } + if (val2 != NULL_TREE + && TREE_CODE (val2) == INTEGER_CST + && simple_cst_equal (fold_build2 (RSHIFT_EXPR, + TREE_TYPE (val), + val2, cst2), val)) + { + enum tree_code new_comp_code = comp_code; + tree tmp, new_val; + + tmp = name2; + if (comp_code == EQ_EXPR || comp_code == NE_EXPR) + { + if (!TYPE_UNSIGNED (TREE_TYPE (val))) + { + tree type = build_nonstandard_integer_type (prec, 1); + tmp = build1 (NOP_EXPR, type, name2); + val2 = fold_convert (type, val2); + } + tmp = fold_build2 (MINUS_EXPR, TREE_TYPE (tmp), tmp, val2); + new_val = double_int_to_tree (TREE_TYPE (tmp), mask); + new_comp_code = comp_code == EQ_EXPR ? LE_EXPR : GT_EXPR; + } + else if (comp_code == LT_EXPR || comp_code == GE_EXPR) + { + double_int minval + = double_int::min_value (prec, TYPE_UNSIGNED (TREE_TYPE (val))); + new_val = val2; + if (minval == tree_to_double_int (new_val)) + new_val = NULL_TREE; + } + else + { + double_int maxval + = double_int::max_value (prec, TYPE_UNSIGNED (TREE_TYPE (val))); + mask |= tree_to_double_int (val2); + if (mask == maxval) + new_val = NULL_TREE; + else + new_val = double_int_to_tree (TREE_TYPE (val2), mask); + } + + if (new_val) + { + if (dump_file) + { + fprintf (dump_file, "Adding assert for "); + print_generic_expr (dump_file, name2, 0); + fprintf (dump_file, " from "); + print_generic_expr (dump_file, tmp, 0); + fprintf (dump_file, "\n"); + } + + register_new_assert_for (name2, tmp, new_comp_code, new_val, + NULL, e, bsi); + retval = true; + } + } + + /* Add asserts for NAME cmp CST and NAME being defined as + NAME = NAME2 & CST2. + + Extract CST2 from the and. + + Also handle + NAME = (unsigned) NAME2; + casts where NAME's type is unsigned and has smaller precision + than NAME2's type as if it was NAME = NAME2 & MASK. */ + names[0] = NULL_TREE; + names[1] = NULL_TREE; + cst2 = NULL_TREE; + if (rhs_code == BIT_AND_EXPR + || (CONVERT_EXPR_CODE_P (rhs_code) + && TREE_CODE (TREE_TYPE (val)) == INTEGER_TYPE + && TYPE_UNSIGNED (TREE_TYPE (val)) + && TYPE_PRECISION (TREE_TYPE (gimple_assign_rhs1 (def_stmt))) + > prec + && !retval)) + { + name2 = gimple_assign_rhs1 (def_stmt); + if (rhs_code == BIT_AND_EXPR) + cst2 = gimple_assign_rhs2 (def_stmt); + else + { + cst2 = TYPE_MAX_VALUE (TREE_TYPE (val)); + nprec = TYPE_PRECISION (TREE_TYPE (name2)); + } + if (TREE_CODE (name2) == SSA_NAME + && INTEGRAL_TYPE_P (TREE_TYPE (name2)) + && TREE_CODE (cst2) == INTEGER_CST + && !integer_zerop (cst2) + && nprec <= HOST_BITS_PER_DOUBLE_INT + && (nprec > 1 + || TYPE_UNSIGNED (TREE_TYPE (val)))) + { + gimple def_stmt2 = SSA_NAME_DEF_STMT (name2); + if (gimple_assign_cast_p (def_stmt2)) + { + names[1] = gimple_assign_rhs1 (def_stmt2); + if (!CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (def_stmt2)) + || !INTEGRAL_TYPE_P (TREE_TYPE (names[1])) + || (TYPE_PRECISION (TREE_TYPE (name2)) + != TYPE_PRECISION (TREE_TYPE (names[1]))) + || !live_on_edge (e, names[1]) + || has_single_use (names[1])) + names[1] = NULL_TREE; + } + if (live_on_edge (e, name2) + && !has_single_use (name2)) + names[0] = name2; + } + } + if (names[0] || names[1]) + { + double_int minv, maxv = double_int_zero, valv, cst2v; + double_int tem, sgnbit; + bool valid_p = false, valn = false, cst2n = false; + enum tree_code ccode = comp_code; + + valv = tree_to_double_int (val).zext (nprec); + cst2v = tree_to_double_int (cst2).zext (nprec); + if (!TYPE_UNSIGNED (TREE_TYPE (val))) + { + valn = valv.sext (nprec).is_negative (); + cst2n = cst2v.sext (nprec).is_negative (); + } + /* If CST2 doesn't have most significant bit set, + but VAL is negative, we have comparison like + if ((x & 0x123) > -4) (always true). Just give up. */ + if (!cst2n && valn) + ccode = ERROR_MARK; + if (cst2n) + sgnbit = double_int_one.llshift (nprec - 1, nprec).zext (nprec); + else + sgnbit = double_int_zero; + minv = valv & cst2v; + switch (ccode) + { + case EQ_EXPR: + /* Minimum unsigned value for equality is VAL & CST2 + (should be equal to VAL, otherwise we probably should + have folded the comparison into false) and + maximum unsigned value is VAL | ~CST2. */ + maxv = valv | ~cst2v; + maxv = maxv.zext (nprec); + valid_p = true; + break; + case NE_EXPR: + tem = valv | ~cst2v; + tem = tem.zext (nprec); + /* If VAL is 0, handle (X & CST2) != 0 as (X & CST2) > 0U. */ + if (valv.is_zero ()) + { + cst2n = false; + sgnbit = double_int_zero; + goto gt_expr; + } + /* If (VAL | ~CST2) is all ones, handle it as + (X & CST2) < VAL. */ + if (tem == double_int::mask (nprec)) + { + cst2n = false; + valn = false; + sgnbit = double_int_zero; + goto lt_expr; + } + if (!cst2n + && cst2v.sext (nprec).is_negative ()) + sgnbit + = double_int_one.llshift (nprec - 1, nprec).zext (nprec); + if (!sgnbit.is_zero ()) + { + if (valv == sgnbit) + { + cst2n = true; + valn = true; + goto gt_expr; + } + if (tem == double_int::mask (nprec - 1)) + { + cst2n = true; + goto lt_expr; + } + if (!cst2n) + sgnbit = double_int_zero; + } + break; + case GE_EXPR: + /* Minimum unsigned value for >= if (VAL & CST2) == VAL + is VAL and maximum unsigned value is ~0. For signed + comparison, if CST2 doesn't have most significant bit + set, handle it similarly. If CST2 has MSB set, + the minimum is the same, and maximum is ~0U/2. */ + if (minv != valv) + { + /* If (VAL & CST2) != VAL, X & CST2 can't be equal to + VAL. */ + minv = masked_increment (valv, cst2v, sgnbit, nprec); + if (minv == valv) + break; + } + maxv = double_int::mask (nprec - (cst2n ? 1 : 0)); + valid_p = true; + break; + case GT_EXPR: + gt_expr: + /* Find out smallest MINV where MINV > VAL + && (MINV & CST2) == MINV, if any. If VAL is signed and + CST2 has MSB set, compute it biased by 1 << (nprec - 1). */ + minv = masked_increment (valv, cst2v, sgnbit, nprec); + if (minv == valv) + break; + maxv = double_int::mask (nprec - (cst2n ? 1 : 0)); + valid_p = true; + break; + case LE_EXPR: + /* Minimum unsigned value for <= is 0 and maximum + unsigned value is VAL | ~CST2 if (VAL & CST2) == VAL. + Otherwise, find smallest VAL2 where VAL2 > VAL + && (VAL2 & CST2) == VAL2 and use (VAL2 - 1) | ~CST2 + as maximum. + For signed comparison, if CST2 doesn't have most + significant bit set, handle it similarly. If CST2 has + MSB set, the maximum is the same and minimum is INT_MIN. */ + if (minv == valv) + maxv = valv; + else + { + maxv = masked_increment (valv, cst2v, sgnbit, nprec); + if (maxv == valv) + break; + maxv -= double_int_one; + } + maxv |= ~cst2v; + maxv = maxv.zext (nprec); + minv = sgnbit; + valid_p = true; + break; + case LT_EXPR: + lt_expr: + /* Minimum unsigned value for < is 0 and maximum + unsigned value is (VAL-1) | ~CST2 if (VAL & CST2) == VAL. + Otherwise, find smallest VAL2 where VAL2 > VAL + && (VAL2 & CST2) == VAL2 and use (VAL2 - 1) | ~CST2 + as maximum. + For signed comparison, if CST2 doesn't have most + significant bit set, handle it similarly. If CST2 has + MSB set, the maximum is the same and minimum is INT_MIN. */ + if (minv == valv) + { + if (valv == sgnbit) + break; + maxv = valv; + } + else + { + maxv = masked_increment (valv, cst2v, sgnbit, nprec); + if (maxv == valv) + break; + } + maxv -= double_int_one; + maxv |= ~cst2v; + maxv = maxv.zext (nprec); + minv = sgnbit; + valid_p = true; + break; + default: + break; + } + if (valid_p + && (maxv - minv).zext (nprec) != double_int::mask (nprec)) + { + tree tmp, new_val, type; + int i; + + for (i = 0; i < 2; i++) + if (names[i]) + { + double_int maxv2 = maxv; + tmp = names[i]; + type = TREE_TYPE (names[i]); + if (!TYPE_UNSIGNED (type)) + { + type = build_nonstandard_integer_type (nprec, 1); + tmp = build1 (NOP_EXPR, type, names[i]); + } + if (!minv.is_zero ()) + { + tmp = build2 (PLUS_EXPR, type, tmp, + double_int_to_tree (type, -minv)); + maxv2 = maxv - minv; + } + new_val = double_int_to_tree (type, maxv2); + + if (dump_file) + { + fprintf (dump_file, "Adding assert for "); + print_generic_expr (dump_file, names[i], 0); + fprintf (dump_file, " from "); + print_generic_expr (dump_file, tmp, 0); + fprintf (dump_file, "\n"); + } + + register_new_assert_for (names[i], tmp, LE_EXPR, + new_val, NULL, e, bsi); + retval = true; + } + } + } + } + + return retval; +} + +/* OP is an operand of a truth value expression which is known to have + a particular value. Register any asserts for OP and for any + operands in OP's defining statement. + + If CODE is EQ_EXPR, then we want to register OP is zero (false), + if CODE is NE_EXPR, then we want to register OP is nonzero (true). */ + +static bool +register_edge_assert_for_1 (tree op, enum tree_code code, + edge e, gimple_stmt_iterator bsi) +{ + bool retval = false; + gimple op_def; + tree val; + enum tree_code rhs_code; + + /* We only care about SSA_NAMEs. */ + if (TREE_CODE (op) != SSA_NAME) + return false; + + /* We know that OP will have a zero or nonzero value. If OP is used + more than once go ahead and register an assert for OP. */ + if (live_on_edge (e, op) + && !has_single_use (op)) + { + val = build_int_cst (TREE_TYPE (op), 0); + register_new_assert_for (op, op, code, val, NULL, e, bsi); + retval = true; + } + + /* Now look at how OP is set. If it's set from a comparison, + a truth operation or some bit operations, then we may be able + to register information about the operands of that assignment. */ + op_def = SSA_NAME_DEF_STMT (op); + if (gimple_code (op_def) != GIMPLE_ASSIGN) + return retval; + + rhs_code = gimple_assign_rhs_code (op_def); + + if (TREE_CODE_CLASS (rhs_code) == tcc_comparison) + { + bool invert = (code == EQ_EXPR ? true : false); + tree op0 = gimple_assign_rhs1 (op_def); + tree op1 = gimple_assign_rhs2 (op_def); + + if (TREE_CODE (op0) == SSA_NAME) + retval |= register_edge_assert_for_2 (op0, e, bsi, rhs_code, op0, op1, + invert); + if (TREE_CODE (op1) == SSA_NAME) + retval |= register_edge_assert_for_2 (op1, e, bsi, rhs_code, op0, op1, + invert); + } + else if ((code == NE_EXPR + && gimple_assign_rhs_code (op_def) == BIT_AND_EXPR) + || (code == EQ_EXPR + && gimple_assign_rhs_code (op_def) == BIT_IOR_EXPR)) + { + /* Recurse on each operand. */ + tree op0 = gimple_assign_rhs1 (op_def); + tree op1 = gimple_assign_rhs2 (op_def); + if (TREE_CODE (op0) == SSA_NAME + && has_single_use (op0)) + retval |= register_edge_assert_for_1 (op0, code, e, bsi); + if (TREE_CODE (op1) == SSA_NAME + && has_single_use (op1)) + retval |= register_edge_assert_for_1 (op1, code, e, bsi); + } + else if (gimple_assign_rhs_code (op_def) == BIT_NOT_EXPR + && TYPE_PRECISION (TREE_TYPE (gimple_assign_lhs (op_def))) == 1) + { + /* Recurse, flipping CODE. */ + code = invert_tree_comparison (code, false); + retval |= register_edge_assert_for_1 (gimple_assign_rhs1 (op_def), + code, e, bsi); + } + else if (gimple_assign_rhs_code (op_def) == SSA_NAME) + { + /* Recurse through the copy. */ + retval |= register_edge_assert_for_1 (gimple_assign_rhs1 (op_def), + code, e, bsi); + } + else if (CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (op_def))) + { + /* Recurse through the type conversion, unless it is a narrowing + conversion or conversion from non-integral type. */ + tree rhs = gimple_assign_rhs1 (op_def); + if (INTEGRAL_TYPE_P (TREE_TYPE (rhs)) + && (TYPE_PRECISION (TREE_TYPE (rhs)) + <= TYPE_PRECISION (TREE_TYPE (op)))) + retval |= register_edge_assert_for_1 (rhs, code, e, bsi); + } + + return retval; +} + +/* Try to register an edge assertion for SSA name NAME on edge E for + the condition COND contributing to the conditional jump pointed to by SI. + Return true if an assertion for NAME could be registered. */ + +static bool +register_edge_assert_for (tree name, edge e, gimple_stmt_iterator si, + enum tree_code cond_code, tree cond_op0, + tree cond_op1) +{ + tree val; + enum tree_code comp_code; + bool retval = false; + bool is_else_edge = (e->flags & EDGE_FALSE_VALUE) != 0; + + /* Do not attempt to infer anything in names that flow through + abnormal edges. */ + if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (name)) + return false; + + if (!extract_code_and_val_from_cond_with_ops (name, cond_code, + cond_op0, cond_op1, + is_else_edge, + &comp_code, &val)) + return false; + + /* Register ASSERT_EXPRs for name. */ + retval |= register_edge_assert_for_2 (name, e, si, cond_code, cond_op0, + cond_op1, is_else_edge); + + + /* If COND is effectively an equality test of an SSA_NAME against + the value zero or one, then we may be able to assert values + for SSA_NAMEs which flow into COND. */ + + /* In the case of NAME == 1 or NAME != 0, for BIT_AND_EXPR defining + statement of NAME we can assert both operands of the BIT_AND_EXPR + have nonzero value. */ + if (((comp_code == EQ_EXPR && integer_onep (val)) + || (comp_code == NE_EXPR && integer_zerop (val)))) + { + gimple def_stmt = SSA_NAME_DEF_STMT (name); + + if (is_gimple_assign (def_stmt) + && gimple_assign_rhs_code (def_stmt) == BIT_AND_EXPR) + { + tree op0 = gimple_assign_rhs1 (def_stmt); + tree op1 = gimple_assign_rhs2 (def_stmt); + retval |= register_edge_assert_for_1 (op0, NE_EXPR, e, si); + retval |= register_edge_assert_for_1 (op1, NE_EXPR, e, si); + } + } + + /* In the case of NAME == 0 or NAME != 1, for BIT_IOR_EXPR defining + statement of NAME we can assert both operands of the BIT_IOR_EXPR + have zero value. */ + if (((comp_code == EQ_EXPR && integer_zerop (val)) + || (comp_code == NE_EXPR && integer_onep (val)))) + { + gimple def_stmt = SSA_NAME_DEF_STMT (name); + + /* For BIT_IOR_EXPR only if NAME == 0 both operands have + necessarily zero value, or if type-precision is one. */ + if (is_gimple_assign (def_stmt) + && (gimple_assign_rhs_code (def_stmt) == BIT_IOR_EXPR + && (TYPE_PRECISION (TREE_TYPE (name)) == 1 + || comp_code == EQ_EXPR))) + { + tree op0 = gimple_assign_rhs1 (def_stmt); + tree op1 = gimple_assign_rhs2 (def_stmt); + retval |= register_edge_assert_for_1 (op0, EQ_EXPR, e, si); + retval |= register_edge_assert_for_1 (op1, EQ_EXPR, e, si); + } + } + + return retval; +} + + +/* Determine whether the outgoing edges of BB should receive an + ASSERT_EXPR for each of the operands of BB's LAST statement. + The last statement of BB must be a COND_EXPR. + + If any of the sub-graphs rooted at BB have an interesting use of + the predicate operands, an assert location node is added to the + list of assertions for the corresponding operands. */ + +static bool +find_conditional_asserts (basic_block bb, gimple last) +{ + bool need_assert; + gimple_stmt_iterator bsi; + tree op; + edge_iterator ei; + edge e; + ssa_op_iter iter; + + need_assert = false; + bsi = gsi_for_stmt (last); + + /* Look for uses of the operands in each of the sub-graphs + rooted at BB. We need to check each of the outgoing edges + separately, so that we know what kind of ASSERT_EXPR to + insert. */ + FOR_EACH_EDGE (e, ei, bb->succs) + { + if (e->dest == bb) + continue; + + /* Register the necessary assertions for each operand in the + conditional predicate. */ + FOR_EACH_SSA_TREE_OPERAND (op, last, iter, SSA_OP_USE) + { + need_assert |= register_edge_assert_for (op, e, bsi, + gimple_cond_code (last), + gimple_cond_lhs (last), + gimple_cond_rhs (last)); + } + } + + return need_assert; +} + +struct case_info +{ + tree expr; + basic_block bb; +}; + +/* Compare two case labels sorting first by the destination bb index + and then by the case value. */ + +static int +compare_case_labels (const void *p1, const void *p2) +{ + const struct case_info *ci1 = (const struct case_info *) p1; + const struct case_info *ci2 = (const struct case_info *) p2; + int idx1 = ci1->bb->index; + int idx2 = ci2->bb->index; + + if (idx1 < idx2) + return -1; + else if (idx1 == idx2) + { + /* Make sure the default label is first in a group. */ + if (!CASE_LOW (ci1->expr)) + return -1; + else if (!CASE_LOW (ci2->expr)) + return 1; + else + return tree_int_cst_compare (CASE_LOW (ci1->expr), + CASE_LOW (ci2->expr)); + } + else + return 1; +} + +/* Determine whether the outgoing edges of BB should receive an + ASSERT_EXPR for each of the operands of BB's LAST statement. + The last statement of BB must be a SWITCH_EXPR. + + If any of the sub-graphs rooted at BB have an interesting use of + the predicate operands, an assert location node is added to the + list of assertions for the corresponding operands. */ + +static bool +find_switch_asserts (basic_block bb, gimple last) +{ + bool need_assert; + gimple_stmt_iterator bsi; + tree op; + edge e; + struct case_info *ci; + size_t n = gimple_switch_num_labels (last); +#if GCC_VERSION >= 4000 + unsigned int idx; +#else + /* Work around GCC 3.4 bug (PR 37086). */ + volatile unsigned int idx; +#endif + + need_assert = false; + bsi = gsi_for_stmt (last); + op = gimple_switch_index (last); + if (TREE_CODE (op) != SSA_NAME) + return false; + + /* Build a vector of case labels sorted by destination label. */ + ci = XNEWVEC (struct case_info, n); + for (idx = 0; idx < n; ++idx) + { + ci[idx].expr = gimple_switch_label (last, idx); + ci[idx].bb = label_to_block (CASE_LABEL (ci[idx].expr)); + } + qsort (ci, n, sizeof (struct case_info), compare_case_labels); + + for (idx = 0; idx < n; ++idx) + { + tree min, max; + tree cl = ci[idx].expr; + basic_block cbb = ci[idx].bb; + + min = CASE_LOW (cl); + max = CASE_HIGH (cl); + + /* If there are multiple case labels with the same destination + we need to combine them to a single value range for the edge. */ + if (idx + 1 < n && cbb == ci[idx + 1].bb) + { + /* Skip labels until the last of the group. */ + do { + ++idx; + } while (idx < n && cbb == ci[idx].bb); + --idx; + + /* Pick up the maximum of the case label range. */ + if (CASE_HIGH (ci[idx].expr)) + max = CASE_HIGH (ci[idx].expr); + else + max = CASE_LOW (ci[idx].expr); + } + + /* Nothing to do if the range includes the default label until we + can register anti-ranges. */ + if (min == NULL_TREE) + continue; + + /* Find the edge to register the assert expr on. */ + e = find_edge (bb, cbb); + + /* Register the necessary assertions for the operand in the + SWITCH_EXPR. */ + need_assert |= register_edge_assert_for (op, e, bsi, + max ? GE_EXPR : EQ_EXPR, + op, + fold_convert (TREE_TYPE (op), + min)); + if (max) + { + need_assert |= register_edge_assert_for (op, e, bsi, LE_EXPR, + op, + fold_convert (TREE_TYPE (op), + max)); + } + } + + XDELETEVEC (ci); + return need_assert; +} + + +/* Traverse all the statements in block BB looking for statements that + may generate useful assertions for the SSA names in their operand. + If a statement produces a useful assertion A for name N_i, then the + list of assertions already generated for N_i is scanned to + determine if A is actually needed. + + If N_i already had the assertion A at a location dominating the + current location, then nothing needs to be done. Otherwise, the + new location for A is recorded instead. + + 1- For every statement S in BB, all the variables used by S are + added to bitmap FOUND_IN_SUBGRAPH. + + 2- If statement S uses an operand N in a way that exposes a known + value range for N, then if N was not already generated by an + ASSERT_EXPR, create a new assert location for N. For instance, + if N is a pointer and the statement dereferences it, we can + assume that N is not NULL. + + 3- COND_EXPRs are a special case of #2. We can derive range + information from the predicate but need to insert different + ASSERT_EXPRs for each of the sub-graphs rooted at the + conditional block. If the last statement of BB is a conditional + expression of the form 'X op Y', then + + a) Remove X and Y from the set FOUND_IN_SUBGRAPH. + + b) If the conditional is the only entry point to the sub-graph + corresponding to the THEN_CLAUSE, recurse into it. On + return, if X and/or Y are marked in FOUND_IN_SUBGRAPH, then + an ASSERT_EXPR is added for the corresponding variable. + + c) Repeat step (b) on the ELSE_CLAUSE. + + d) Mark X and Y in FOUND_IN_SUBGRAPH. + + For instance, + + if (a == 9) + b = a; + else + b = c + 1; + + In this case, an assertion on the THEN clause is useful to + determine that 'a' is always 9 on that edge. However, an assertion + on the ELSE clause would be unnecessary. + + 4- If BB does not end in a conditional expression, then we recurse + into BB's dominator children. + + At the end of the recursive traversal, every SSA name will have a + list of locations where ASSERT_EXPRs should be added. When a new + location for name N is found, it is registered by calling + register_new_assert_for. That function keeps track of all the + registered assertions to prevent adding unnecessary assertions. + For instance, if a pointer P_4 is dereferenced more than once in a + dominator tree, only the location dominating all the dereference of + P_4 will receive an ASSERT_EXPR. + + If this function returns true, then it means that there are names + for which we need to generate ASSERT_EXPRs. Those assertions are + inserted by process_assert_insertions. */ + +static bool +find_assert_locations_1 (basic_block bb, sbitmap live) +{ + gimple_stmt_iterator si; + gimple last; + bool need_assert; + + need_assert = false; + last = last_stmt (bb); + + /* If BB's last statement is a conditional statement involving integer + operands, determine if we need to add ASSERT_EXPRs. */ + if (last + && gimple_code (last) == GIMPLE_COND + && !fp_predicate (last) + && !ZERO_SSA_OPERANDS (last, SSA_OP_USE)) + need_assert |= find_conditional_asserts (bb, last); + + /* If BB's last statement is a switch statement involving integer + operands, determine if we need to add ASSERT_EXPRs. */ + if (last + && gimple_code (last) == GIMPLE_SWITCH + && !ZERO_SSA_OPERANDS (last, SSA_OP_USE)) + need_assert |= find_switch_asserts (bb, last); + + /* Traverse all the statements in BB marking used names and looking + for statements that may infer assertions for their used operands. */ + for (si = gsi_last_bb (bb); !gsi_end_p (si); gsi_prev (&si)) + { + gimple stmt; + tree op; + ssa_op_iter i; + + stmt = gsi_stmt (si); + + if (is_gimple_debug (stmt)) + continue; + + /* See if we can derive an assertion for any of STMT's operands. */ + FOR_EACH_SSA_TREE_OPERAND (op, stmt, i, SSA_OP_USE) + { + tree value; + enum tree_code comp_code; + + /* If op is not live beyond this stmt, do not bother to insert + asserts for it. */ + if (!bitmap_bit_p (live, SSA_NAME_VERSION (op))) + continue; + + /* If OP is used in such a way that we can infer a value + range for it, and we don't find a previous assertion for + it, create a new assertion location node for OP. */ + if (infer_value_range (stmt, op, &comp_code, &value)) + { + /* If we are able to infer a nonzero value range for OP, + then walk backwards through the use-def chain to see if OP + was set via a typecast. + + If so, then we can also infer a nonzero value range + for the operand of the NOP_EXPR. */ + if (comp_code == NE_EXPR && integer_zerop (value)) + { + tree t = op; + gimple def_stmt = SSA_NAME_DEF_STMT (t); + + while (is_gimple_assign (def_stmt) + && gimple_assign_rhs_code (def_stmt) == NOP_EXPR + && TREE_CODE + (gimple_assign_rhs1 (def_stmt)) == SSA_NAME + && POINTER_TYPE_P + (TREE_TYPE (gimple_assign_rhs1 (def_stmt)))) + { + t = gimple_assign_rhs1 (def_stmt); + def_stmt = SSA_NAME_DEF_STMT (t); + + /* Note we want to register the assert for the + operand of the NOP_EXPR after SI, not after the + conversion. */ + if (! has_single_use (t)) + { + register_new_assert_for (t, t, comp_code, value, + bb, NULL, si); + need_assert = true; + } + } + } + + register_new_assert_for (op, op, comp_code, value, bb, NULL, si); + need_assert = true; + } + } + + /* Update live. */ + FOR_EACH_SSA_TREE_OPERAND (op, stmt, i, SSA_OP_USE) + bitmap_set_bit (live, SSA_NAME_VERSION (op)); + FOR_EACH_SSA_TREE_OPERAND (op, stmt, i, SSA_OP_DEF) + bitmap_clear_bit (live, SSA_NAME_VERSION (op)); + } + + /* Traverse all PHI nodes in BB, updating live. */ + for (si = gsi_start_phis (bb); !gsi_end_p (si); gsi_next (&si)) + { + use_operand_p arg_p; + ssa_op_iter i; + gimple phi = gsi_stmt (si); + tree res = gimple_phi_result (phi); + + if (virtual_operand_p (res)) + continue; + + FOR_EACH_PHI_ARG (arg_p, phi, i, SSA_OP_USE) + { + tree arg = USE_FROM_PTR (arg_p); + if (TREE_CODE (arg) == SSA_NAME) + bitmap_set_bit (live, SSA_NAME_VERSION (arg)); + } + + bitmap_clear_bit (live, SSA_NAME_VERSION (res)); + } + + return need_assert; +} + +/* Do an RPO walk over the function computing SSA name liveness + on-the-fly and deciding on assert expressions to insert. + Returns true if there are assert expressions to be inserted. */ + +static bool +find_assert_locations (void) +{ + int *rpo = XNEWVEC (int, last_basic_block_for_fn (cfun)); + int *bb_rpo = XNEWVEC (int, last_basic_block_for_fn (cfun)); + int *last_rpo = XCNEWVEC (int, last_basic_block_for_fn (cfun)); + int rpo_cnt, i; + bool need_asserts; + + live = XCNEWVEC (sbitmap, last_basic_block_for_fn (cfun)); + rpo_cnt = pre_and_rev_post_order_compute (NULL, rpo, false); + for (i = 0; i < rpo_cnt; ++i) + bb_rpo[rpo[i]] = i; + + /* Pre-seed loop latch liveness from loop header PHI nodes. Due to + the order we compute liveness and insert asserts we otherwise + fail to insert asserts into the loop latch. */ + loop_p loop; + FOR_EACH_LOOP (loop, 0) + { + i = loop->latch->index; + unsigned int j = single_succ_edge (loop->latch)->dest_idx; + for (gimple_stmt_iterator gsi = gsi_start_phis (loop->header); + !gsi_end_p (gsi); gsi_next (&gsi)) + { + gimple phi = gsi_stmt (gsi); + if (virtual_operand_p (gimple_phi_result (phi))) + continue; + tree arg = gimple_phi_arg_def (phi, j); + if (TREE_CODE (arg) == SSA_NAME) + { + if (live[i] == NULL) + { + live[i] = sbitmap_alloc (num_ssa_names); + bitmap_clear (live[i]); + } + bitmap_set_bit (live[i], SSA_NAME_VERSION (arg)); + } + } + } + + need_asserts = false; + for (i = rpo_cnt - 1; i >= 0; --i) + { + basic_block bb = BASIC_BLOCK_FOR_FN (cfun, rpo[i]); + edge e; + edge_iterator ei; + + if (!live[rpo[i]]) + { + live[rpo[i]] = sbitmap_alloc (num_ssa_names); + bitmap_clear (live[rpo[i]]); + } + + /* Process BB and update the live information with uses in + this block. */ + need_asserts |= find_assert_locations_1 (bb, live[rpo[i]]); + + /* Merge liveness into the predecessor blocks and free it. */ + if (!bitmap_empty_p (live[rpo[i]])) + { + int pred_rpo = i; + FOR_EACH_EDGE (e, ei, bb->preds) + { + int pred = e->src->index; + if ((e->flags & EDGE_DFS_BACK) || pred == ENTRY_BLOCK) + continue; + + if (!live[pred]) + { + live[pred] = sbitmap_alloc (num_ssa_names); + bitmap_clear (live[pred]); + } + bitmap_ior (live[pred], live[pred], live[rpo[i]]); + + if (bb_rpo[pred] < pred_rpo) + pred_rpo = bb_rpo[pred]; + } + + /* Record the RPO number of the last visited block that needs + live information from this block. */ + last_rpo[rpo[i]] = pred_rpo; + } + else + { + sbitmap_free (live[rpo[i]]); + live[rpo[i]] = NULL; + } + + /* We can free all successors live bitmaps if all their + predecessors have been visited already. */ + FOR_EACH_EDGE (e, ei, bb->succs) + if (last_rpo[e->dest->index] == i + && live[e->dest->index]) + { + sbitmap_free (live[e->dest->index]); + live[e->dest->index] = NULL; + } + } + + XDELETEVEC (rpo); + XDELETEVEC (bb_rpo); + XDELETEVEC (last_rpo); + for (i = 0; i < last_basic_block_for_fn (cfun); ++i) + if (live[i]) + sbitmap_free (live[i]); + XDELETEVEC (live); + + return need_asserts; +} + +/* Create an ASSERT_EXPR for NAME and insert it in the location + indicated by LOC. Return true if we made any edge insertions. */ + +static bool +process_assert_insertions_for (tree name, assert_locus_t loc) +{ + /* Build the comparison expression NAME_i COMP_CODE VAL. */ + gimple stmt; + tree cond; + gimple assert_stmt; + edge_iterator ei; + edge e; + + /* If we have X <=> X do not insert an assert expr for that. */ + if (loc->expr == loc->val) + return false; + + cond = build2 (loc->comp_code, boolean_type_node, loc->expr, loc->val); + assert_stmt = build_assert_expr_for (cond, name); + if (loc->e) + { + /* We have been asked to insert the assertion on an edge. This + is used only by COND_EXPR and SWITCH_EXPR assertions. */ + gcc_checking_assert (gimple_code (gsi_stmt (loc->si)) == GIMPLE_COND + || (gimple_code (gsi_stmt (loc->si)) + == GIMPLE_SWITCH)); + + gsi_insert_on_edge (loc->e, assert_stmt); + return true; + } + + /* Otherwise, we can insert right after LOC->SI iff the + statement must not be the last statement in the block. */ + stmt = gsi_stmt (loc->si); + if (!stmt_ends_bb_p (stmt)) + { + gsi_insert_after (&loc->si, assert_stmt, GSI_SAME_STMT); + return false; + } + + /* If STMT must be the last statement in BB, we can only insert new + assertions on the non-abnormal edge out of BB. Note that since + STMT is not control flow, there may only be one non-abnormal edge + out of BB. */ + FOR_EACH_EDGE (e, ei, loc->bb->succs) + if (!(e->flags & EDGE_ABNORMAL)) + { + gsi_insert_on_edge (e, assert_stmt); + return true; + } + + gcc_unreachable (); +} + + +/* Process all the insertions registered for every name N_i registered + in NEED_ASSERT_FOR. The list of assertions to be inserted are + found in ASSERTS_FOR[i]. */ + +static void +process_assert_insertions (void) +{ + unsigned i; + bitmap_iterator bi; + bool update_edges_p = false; + int num_asserts = 0; + + if (dump_file && (dump_flags & TDF_DETAILS)) + dump_all_asserts (dump_file); + + EXECUTE_IF_SET_IN_BITMAP (need_assert_for, 0, i, bi) + { + assert_locus_t loc = asserts_for[i]; + gcc_assert (loc); + + while (loc) + { + assert_locus_t next = loc->next; + update_edges_p |= process_assert_insertions_for (ssa_name (i), loc); + free (loc); + loc = next; + num_asserts++; + } + } + + if (update_edges_p) + gsi_commit_edge_inserts (); + + statistics_counter_event (cfun, "Number of ASSERT_EXPR expressions inserted", + num_asserts); +} + + +/* Traverse the flowgraph looking for conditional jumps to insert range + expressions. These range expressions are meant to provide information + to optimizations that need to reason in terms of value ranges. They + will not be expanded into RTL. For instance, given: + + x = ... + y = ... + if (x < y) + y = x - 2; + else + x = y + 3; + + this pass will transform the code into: + + x = ... + y = ... + if (x < y) + { + x = ASSERT_EXPR <x, x < y> + y = x - 2 + } + else + { + y = ASSERT_EXPR <y, x <= y> + x = y + 3 + } + + The idea is that once copy and constant propagation have run, other + optimizations will be able to determine what ranges of values can 'x' + take in different paths of the code, simply by checking the reaching + definition of 'x'. */ + +static void +insert_range_assertions (void) +{ + need_assert_for = BITMAP_ALLOC (NULL); + asserts_for = XCNEWVEC (assert_locus_t, num_ssa_names); + + calculate_dominance_info (CDI_DOMINATORS); + + if (find_assert_locations ()) + { + process_assert_insertions (); + update_ssa (TODO_update_ssa_no_phi); + } + + if (dump_file && (dump_flags & TDF_DETAILS)) + { + fprintf (dump_file, "\nSSA form after inserting ASSERT_EXPRs\n"); + dump_function_to_file (current_function_decl, dump_file, dump_flags); + } + + free (asserts_for); + BITMAP_FREE (need_assert_for); +} + +/* Checks one ARRAY_REF in REF, located at LOCUS. Ignores flexible arrays + and "struct" hacks. If VRP can determine that the + array subscript is a constant, check if it is outside valid + range. If the array subscript is a RANGE, warn if it is + non-overlapping with valid range. + IGNORE_OFF_BY_ONE is true if the ARRAY_REF is inside a ADDR_EXPR. */ + +static void +check_array_ref (location_t location, tree ref, bool ignore_off_by_one) +{ + value_range_t* vr = NULL; + tree low_sub, up_sub; + tree low_bound, up_bound, up_bound_p1; + tree base; + + if (TREE_NO_WARNING (ref)) + return; + + low_sub = up_sub = TREE_OPERAND (ref, 1); + up_bound = array_ref_up_bound (ref); + + /* Can not check flexible arrays. */ + if (!up_bound + || TREE_CODE (up_bound) != INTEGER_CST) + return; + + /* Accesses to trailing arrays via pointers may access storage + beyond the types array bounds. */ + base = get_base_address (ref); + if (base && TREE_CODE (base) == MEM_REF) + { + tree cref, next = NULL_TREE; + + if (TREE_CODE (TREE_OPERAND (ref, 0)) != COMPONENT_REF) + return; + + cref = TREE_OPERAND (ref, 0); + if (TREE_CODE (TREE_TYPE (TREE_OPERAND (cref, 0))) == RECORD_TYPE) + for (next = DECL_CHAIN (TREE_OPERAND (cref, 1)); + next && TREE_CODE (next) != FIELD_DECL; + next = DECL_CHAIN (next)) + ; + + /* If this is the last field in a struct type or a field in a + union type do not warn. */ + if (!next) + return; + } + + low_bound = array_ref_low_bound (ref); + up_bound_p1 = int_const_binop (PLUS_EXPR, up_bound, integer_one_node); + + if (TREE_CODE (low_sub) == SSA_NAME) + { + vr = get_value_range (low_sub); + if (vr->type == VR_RANGE || vr->type == VR_ANTI_RANGE) + { + low_sub = vr->type == VR_RANGE ? vr->max : vr->min; + up_sub = vr->type == VR_RANGE ? vr->min : vr->max; + } + } + + if (vr && vr->type == VR_ANTI_RANGE) + { + if (TREE_CODE (up_sub) == INTEGER_CST + && tree_int_cst_lt (up_bound, up_sub) + && TREE_CODE (low_sub) == INTEGER_CST + && tree_int_cst_lt (low_sub, low_bound)) + { + warning_at (location, OPT_Warray_bounds, + "array subscript is outside array bounds"); + TREE_NO_WARNING (ref) = 1; + } + } + else if (TREE_CODE (up_sub) == INTEGER_CST + && (ignore_off_by_one + ? (tree_int_cst_lt (up_bound, up_sub) + && !tree_int_cst_equal (up_bound_p1, up_sub)) + : (tree_int_cst_lt (up_bound, up_sub) + || tree_int_cst_equal (up_bound_p1, up_sub)))) + { + if (dump_file && (dump_flags & TDF_DETAILS)) + { + fprintf (dump_file, "Array bound warning for "); + dump_generic_expr (MSG_NOTE, TDF_SLIM, ref); + fprintf (dump_file, "\n"); + } + warning_at (location, OPT_Warray_bounds, + "array subscript is above array bounds"); + TREE_NO_WARNING (ref) = 1; + } + else if (TREE_CODE (low_sub) == INTEGER_CST + && tree_int_cst_lt (low_sub, low_bound)) + { + if (dump_file && (dump_flags & TDF_DETAILS)) + { + fprintf (dump_file, "Array bound warning for "); + dump_generic_expr (MSG_NOTE, TDF_SLIM, ref); + fprintf (dump_file, "\n"); + } + warning_at (location, OPT_Warray_bounds, + "array subscript is below array bounds"); + TREE_NO_WARNING (ref) = 1; + } +} + +/* Searches if the expr T, located at LOCATION computes + address of an ARRAY_REF, and call check_array_ref on it. */ + +static void +search_for_addr_array (tree t, location_t location) +{ + while (TREE_CODE (t) == SSA_NAME) + { + gimple g = SSA_NAME_DEF_STMT (t); + + if (gimple_code (g) != GIMPLE_ASSIGN) + return; + + if (get_gimple_rhs_class (gimple_assign_rhs_code (g)) + != GIMPLE_SINGLE_RHS) + return; + + t = gimple_assign_rhs1 (g); + } + + + /* We are only interested in addresses of ARRAY_REF's. */ + if (TREE_CODE (t) != ADDR_EXPR) + return; + + /* Check each ARRAY_REFs in the reference chain. */ + do + { + if (TREE_CODE (t) == ARRAY_REF) + check_array_ref (location, t, true /*ignore_off_by_one*/); + + t = TREE_OPERAND (t, 0); + } + while (handled_component_p (t)); + + if (TREE_CODE (t) == MEM_REF + && TREE_CODE (TREE_OPERAND (t, 0)) == ADDR_EXPR + && !TREE_NO_WARNING (t)) + { + tree tem = TREE_OPERAND (TREE_OPERAND (t, 0), 0); + tree low_bound, up_bound, el_sz; + double_int idx; + if (TREE_CODE (TREE_TYPE (tem)) != ARRAY_TYPE + || TREE_CODE (TREE_TYPE (TREE_TYPE (tem))) == ARRAY_TYPE + || !TYPE_DOMAIN (TREE_TYPE (tem))) + return; + + low_bound = TYPE_MIN_VALUE (TYPE_DOMAIN (TREE_TYPE (tem))); + up_bound = TYPE_MAX_VALUE (TYPE_DOMAIN (TREE_TYPE (tem))); + el_sz = TYPE_SIZE_UNIT (TREE_TYPE (TREE_TYPE (tem))); + if (!low_bound + || TREE_CODE (low_bound) != INTEGER_CST + || !up_bound + || TREE_CODE (up_bound) != INTEGER_CST + || !el_sz + || TREE_CODE (el_sz) != INTEGER_CST) + return; + + idx = mem_ref_offset (t); + idx = idx.sdiv (tree_to_double_int (el_sz), TRUNC_DIV_EXPR); + if (idx.slt (double_int_zero)) + { + if (dump_file && (dump_flags & TDF_DETAILS)) + { + fprintf (dump_file, "Array bound warning for "); + dump_generic_expr (MSG_NOTE, TDF_SLIM, t); + fprintf (dump_file, "\n"); + } + warning_at (location, OPT_Warray_bounds, + "array subscript is below array bounds"); + TREE_NO_WARNING (t) = 1; + } + else if (idx.sgt (tree_to_double_int (up_bound) + - tree_to_double_int (low_bound) + + double_int_one)) + { + if (dump_file && (dump_flags & TDF_DETAILS)) + { + fprintf (dump_file, "Array bound warning for "); + dump_generic_expr (MSG_NOTE, TDF_SLIM, t); + fprintf (dump_file, "\n"); + } + warning_at (location, OPT_Warray_bounds, + "array subscript is above array bounds"); + TREE_NO_WARNING (t) = 1; + } + } +} + +/* walk_tree() callback that checks if *TP is + an ARRAY_REF inside an ADDR_EXPR (in which an array + subscript one outside the valid range is allowed). Call + check_array_ref for each ARRAY_REF found. The location is + passed in DATA. */ + +static tree +check_array_bounds (tree *tp, int *walk_subtree, void *data) +{ + tree t = *tp; + struct walk_stmt_info *wi = (struct walk_stmt_info *) data; + location_t location; + + if (EXPR_HAS_LOCATION (t)) + location = EXPR_LOCATION (t); + else + { + location_t *locp = (location_t *) wi->info; + location = *locp; + } + + *walk_subtree = TRUE; + + if (TREE_CODE (t) == ARRAY_REF) + check_array_ref (location, t, false /*ignore_off_by_one*/); + + if (TREE_CODE (t) == MEM_REF + || (TREE_CODE (t) == RETURN_EXPR && TREE_OPERAND (t, 0))) + search_for_addr_array (TREE_OPERAND (t, 0), location); + + if (TREE_CODE (t) == ADDR_EXPR) + *walk_subtree = FALSE; + + return NULL_TREE; +} + +/* Walk over all statements of all reachable BBs and call check_array_bounds + on them. */ + +static void +check_all_array_refs (void) +{ + basic_block bb; + gimple_stmt_iterator si; + + FOR_EACH_BB_FN (bb, cfun) + { + edge_iterator ei; + edge e; + bool executable = false; + + /* Skip blocks that were found to be unreachable. */ + FOR_EACH_EDGE (e, ei, bb->preds) + executable |= !!(e->flags & EDGE_EXECUTABLE); + if (!executable) + continue; + + for (si = gsi_start_bb (bb); !gsi_end_p (si); gsi_next (&si)) + { + gimple stmt = gsi_stmt (si); + struct walk_stmt_info wi; + if (!gimple_has_location (stmt)) + continue; + + if (is_gimple_call (stmt)) + { + size_t i; + size_t n = gimple_call_num_args (stmt); + for (i = 0; i < n; i++) + { + tree arg = gimple_call_arg (stmt, i); + search_for_addr_array (arg, gimple_location (stmt)); + } + } + else + { + memset (&wi, 0, sizeof (wi)); + wi.info = CONST_CAST (void *, (const void *) + gimple_location_ptr (stmt)); + + walk_gimple_op (gsi_stmt (si), + check_array_bounds, + &wi); + } + } + } +} + +/* Return true if all imm uses of VAR are either in STMT, or + feed (optionally through a chain of single imm uses) GIMPLE_COND + in basic block COND_BB. */ + +static bool +all_imm_uses_in_stmt_or_feed_cond (tree var, gimple stmt, basic_block cond_bb) +{ + use_operand_p use_p, use2_p; + imm_use_iterator iter; + + FOR_EACH_IMM_USE_FAST (use_p, iter, var) + if (USE_STMT (use_p) != stmt) + { + gimple use_stmt = USE_STMT (use_p), use_stmt2; + if (is_gimple_debug (use_stmt)) + continue; + while (is_gimple_assign (use_stmt) + && TREE_CODE (gimple_assign_lhs (use_stmt)) == SSA_NAME + && single_imm_use (gimple_assign_lhs (use_stmt), + &use2_p, &use_stmt2)) + use_stmt = use_stmt2; + if (gimple_code (use_stmt) != GIMPLE_COND + || gimple_bb (use_stmt) != cond_bb) + return false; + } + return true; +} + +/* Handle + _4 = x_3 & 31; + if (_4 != 0) + goto <bb 6>; + else + goto <bb 7>; + <bb 6>: + __builtin_unreachable (); + <bb 7>: + x_5 = ASSERT_EXPR <x_3, ...>; + If x_3 has no other immediate uses (checked by caller), + var is the x_3 var from ASSERT_EXPR, we can clear low 5 bits + from the non-zero bitmask. */ + +static void +maybe_set_nonzero_bits (basic_block bb, tree var) +{ + edge e = single_pred_edge (bb); + basic_block cond_bb = e->src; + gimple stmt = last_stmt (cond_bb); + tree cst; + + if (stmt == NULL + || gimple_code (stmt) != GIMPLE_COND + || gimple_cond_code (stmt) != ((e->flags & EDGE_TRUE_VALUE) + ? EQ_EXPR : NE_EXPR) + || TREE_CODE (gimple_cond_lhs (stmt)) != SSA_NAME + || !integer_zerop (gimple_cond_rhs (stmt))) + return; + + stmt = SSA_NAME_DEF_STMT (gimple_cond_lhs (stmt)); + if (!is_gimple_assign (stmt) + || gimple_assign_rhs_code (stmt) != BIT_AND_EXPR + || TREE_CODE (gimple_assign_rhs2 (stmt)) != INTEGER_CST) + return; + if (gimple_assign_rhs1 (stmt) != var) + { + gimple stmt2; + + if (TREE_CODE (gimple_assign_rhs1 (stmt)) != SSA_NAME) + return; + stmt2 = SSA_NAME_DEF_STMT (gimple_assign_rhs1 (stmt)); + if (!gimple_assign_cast_p (stmt2) + || gimple_assign_rhs1 (stmt2) != var + || !CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (stmt2)) + || (TYPE_PRECISION (TREE_TYPE (gimple_assign_rhs1 (stmt))) + != TYPE_PRECISION (TREE_TYPE (var)))) + return; + } + cst = gimple_assign_rhs2 (stmt); + set_nonzero_bits (var, (get_nonzero_bits (var) + & ~tree_to_double_int (cst))); +} + +/* Convert range assertion expressions into the implied copies and + copy propagate away the copies. Doing the trivial copy propagation + here avoids the need to run the full copy propagation pass after + VRP. + + FIXME, this will eventually lead to copy propagation removing the + names that had useful range information attached to them. For + instance, if we had the assertion N_i = ASSERT_EXPR <N_j, N_j > 3>, + then N_i will have the range [3, +INF]. + + However, by converting the assertion into the implied copy + operation N_i = N_j, we will then copy-propagate N_j into the uses + of N_i and lose the range information. We may want to hold on to + ASSERT_EXPRs a little while longer as the ranges could be used in + things like jump threading. + + The problem with keeping ASSERT_EXPRs around is that passes after + VRP need to handle them appropriately. + + Another approach would be to make the range information a first + class property of the SSA_NAME so that it can be queried from + any pass. This is made somewhat more complex by the need for + multiple ranges to be associated with one SSA_NAME. */ + +static void +remove_range_assertions (void) +{ + basic_block bb; + gimple_stmt_iterator si; + /* 1 if looking at ASSERT_EXPRs immediately at the beginning of + a basic block preceeded by GIMPLE_COND branching to it and + __builtin_trap, -1 if not yet checked, 0 otherwise. */ + int is_unreachable; + + /* Note that the BSI iterator bump happens at the bottom of the + loop and no bump is necessary if we're removing the statement + referenced by the current BSI. */ + FOR_EACH_BB_FN (bb, cfun) + for (si = gsi_after_labels (bb), is_unreachable = -1; !gsi_end_p (si);) + { + gimple stmt = gsi_stmt (si); + gimple use_stmt; + + if (is_gimple_assign (stmt) + && gimple_assign_rhs_code (stmt) == ASSERT_EXPR) + { + tree lhs = gimple_assign_lhs (stmt); + tree rhs = gimple_assign_rhs1 (stmt); + tree var; + tree cond = fold (ASSERT_EXPR_COND (rhs)); + use_operand_p use_p; + imm_use_iterator iter; + + gcc_assert (cond != boolean_false_node); + + var = ASSERT_EXPR_VAR (rhs); + gcc_assert (TREE_CODE (var) == SSA_NAME); + + if (!POINTER_TYPE_P (TREE_TYPE (lhs)) + && SSA_NAME_RANGE_INFO (lhs)) + { + if (is_unreachable == -1) + { + is_unreachable = 0; + if (single_pred_p (bb) + && assert_unreachable_fallthru_edge_p + (single_pred_edge (bb))) + is_unreachable = 1; + } + /* Handle + if (x_7 >= 10 && x_7 < 20) + __builtin_unreachable (); + x_8 = ASSERT_EXPR <x_7, ...>; + if the only uses of x_7 are in the ASSERT_EXPR and + in the condition. In that case, we can copy the + range info from x_8 computed in this pass also + for x_7. */ + if (is_unreachable + && all_imm_uses_in_stmt_or_feed_cond (var, stmt, + single_pred (bb))) + { + set_range_info (var, SSA_NAME_RANGE_TYPE (lhs), + SSA_NAME_RANGE_INFO (lhs)->min, + SSA_NAME_RANGE_INFO (lhs)->max); + maybe_set_nonzero_bits (bb, var); + } + } + + /* Propagate the RHS into every use of the LHS. */ + FOR_EACH_IMM_USE_STMT (use_stmt, iter, lhs) + FOR_EACH_IMM_USE_ON_STMT (use_p, iter) + SET_USE (use_p, var); + + /* And finally, remove the copy, it is not needed. */ + gsi_remove (&si, true); + release_defs (stmt); + } + else + { + gsi_next (&si); + is_unreachable = 0; + } + } +} + + +/* Return true if STMT is interesting for VRP. */ + +static bool +stmt_interesting_for_vrp (gimple stmt) +{ + if (gimple_code (stmt) == GIMPLE_PHI) + { + tree res = gimple_phi_result (stmt); + return (!virtual_operand_p (res) + && (INTEGRAL_TYPE_P (TREE_TYPE (res)) + || POINTER_TYPE_P (TREE_TYPE (res)))); + } + else if (is_gimple_assign (stmt) || is_gimple_call (stmt)) + { + tree lhs = gimple_get_lhs (stmt); + + /* In general, assignments with virtual operands are not useful + for deriving ranges, with the obvious exception of calls to + builtin functions. */ + if (lhs && TREE_CODE (lhs) == SSA_NAME + && (INTEGRAL_TYPE_P (TREE_TYPE (lhs)) + || POINTER_TYPE_P (TREE_TYPE (lhs))) + && (is_gimple_call (stmt) + || !gimple_vuse (stmt))) + return true; + } + else if (gimple_code (stmt) == GIMPLE_COND + || gimple_code (stmt) == GIMPLE_SWITCH) + return true; + + return false; +} + + +/* Initialize local data structures for VRP. */ + +static void +vrp_initialize (void) +{ + basic_block bb; + + values_propagated = false; + num_vr_values = num_ssa_names; + vr_value = XCNEWVEC (value_range_t *, num_vr_values); + vr_phi_edge_counts = XCNEWVEC (int, num_ssa_names); + + FOR_EACH_BB_FN (bb, cfun) + { + gimple_stmt_iterator si; + + for (si = gsi_start_phis (bb); !gsi_end_p (si); gsi_next (&si)) + { + gimple phi = gsi_stmt (si); + if (!stmt_interesting_for_vrp (phi)) + { + tree lhs = PHI_RESULT (phi); + set_value_range_to_varying (get_value_range (lhs)); + prop_set_simulate_again (phi, false); + } + else + prop_set_simulate_again (phi, true); + } + + for (si = gsi_start_bb (bb); !gsi_end_p (si); gsi_next (&si)) + { + gimple stmt = gsi_stmt (si); + + /* If the statement is a control insn, then we do not + want to avoid simulating the statement once. Failure + to do so means that those edges will never get added. */ + if (stmt_ends_bb_p (stmt)) + prop_set_simulate_again (stmt, true); + else if (!stmt_interesting_for_vrp (stmt)) + { + ssa_op_iter i; + tree def; + FOR_EACH_SSA_TREE_OPERAND (def, stmt, i, SSA_OP_DEF) + set_value_range_to_varying (get_value_range (def)); + prop_set_simulate_again (stmt, false); + } + else + prop_set_simulate_again (stmt, true); + } + } +} + +/* Return the singleton value-range for NAME or NAME. */ + +static inline tree +vrp_valueize (tree name) +{ + if (TREE_CODE (name) == SSA_NAME) + { + value_range_t *vr = get_value_range (name); + if (vr->type == VR_RANGE + && (vr->min == vr->max + || operand_equal_p (vr->min, vr->max, 0))) + return vr->min; + } + return name; +} + +/* Visit assignment STMT. If it produces an interesting range, record + the SSA name in *OUTPUT_P. */ + +static enum ssa_prop_result +vrp_visit_assignment_or_call (gimple stmt, tree *output_p) +{ + tree def, lhs; + ssa_op_iter iter; + enum gimple_code code = gimple_code (stmt); + lhs = gimple_get_lhs (stmt); + + /* We only keep track of ranges in integral and pointer types. */ + if (TREE_CODE (lhs) == SSA_NAME + && ((INTEGRAL_TYPE_P (TREE_TYPE (lhs)) + /* It is valid to have NULL MIN/MAX values on a type. See + build_range_type. */ + && TYPE_MIN_VALUE (TREE_TYPE (lhs)) + && TYPE_MAX_VALUE (TREE_TYPE (lhs))) + || POINTER_TYPE_P (TREE_TYPE (lhs)))) + { + value_range_t new_vr = VR_INITIALIZER; + + /* Try folding the statement to a constant first. */ + tree tem = gimple_fold_stmt_to_constant (stmt, vrp_valueize); + if (tem) + set_value_range_to_value (&new_vr, tem, NULL); + /* Then dispatch to value-range extracting functions. */ + else if (code == GIMPLE_CALL) + extract_range_basic (&new_vr, stmt); + else + extract_range_from_assignment (&new_vr, stmt); + + if (update_value_range (lhs, &new_vr)) + { + *output_p = lhs; + + if (dump_file && (dump_flags & TDF_DETAILS)) + { + fprintf (dump_file, "Found new range for "); + print_generic_expr (dump_file, lhs, 0); + fprintf (dump_file, ": "); + dump_value_range (dump_file, &new_vr); + fprintf (dump_file, "\n\n"); + } + + if (new_vr.type == VR_VARYING) + return SSA_PROP_VARYING; + + return SSA_PROP_INTERESTING; + } + + return SSA_PROP_NOT_INTERESTING; + } + + /* Every other statement produces no useful ranges. */ + FOR_EACH_SSA_TREE_OPERAND (def, stmt, iter, SSA_OP_DEF) + set_value_range_to_varying (get_value_range (def)); + + return SSA_PROP_VARYING; +} + +/* Helper that gets the value range of the SSA_NAME with version I + or a symbolic range containing the SSA_NAME only if the value range + is varying or undefined. */ + +static inline value_range_t +get_vr_for_comparison (int i) +{ + value_range_t vr = *get_value_range (ssa_name (i)); + + /* If name N_i does not have a valid range, use N_i as its own + range. This allows us to compare against names that may + have N_i in their ranges. */ + if (vr.type == VR_VARYING || vr.type == VR_UNDEFINED) + { + vr.type = VR_RANGE; + vr.min = ssa_name (i); + vr.max = ssa_name (i); + } + + return vr; +} + +/* Compare all the value ranges for names equivalent to VAR with VAL + using comparison code COMP. Return the same value returned by + compare_range_with_value, including the setting of + *STRICT_OVERFLOW_P. */ + +static tree +compare_name_with_value (enum tree_code comp, tree var, tree val, + bool *strict_overflow_p) +{ + bitmap_iterator bi; + unsigned i; + bitmap e; + tree retval, t; + int used_strict_overflow; + bool sop; + value_range_t equiv_vr; + + /* Get the set of equivalences for VAR. */ + e = get_value_range (var)->equiv; + + /* Start at -1. Set it to 0 if we do a comparison without relying + on overflow, or 1 if all comparisons rely on overflow. */ + used_strict_overflow = -1; + + /* Compare vars' value range with val. */ + equiv_vr = get_vr_for_comparison (SSA_NAME_VERSION (var)); + sop = false; + retval = compare_range_with_value (comp, &equiv_vr, val, &sop); + if (retval) + used_strict_overflow = sop ? 1 : 0; + + /* If the equiv set is empty we have done all work we need to do. */ + if (e == NULL) + { + if (retval + && used_strict_overflow > 0) + *strict_overflow_p = true; + return retval; + } + + EXECUTE_IF_SET_IN_BITMAP (e, 0, i, bi) + { + equiv_vr = get_vr_for_comparison (i); + sop = false; + t = compare_range_with_value (comp, &equiv_vr, val, &sop); + if (t) + { + /* If we get different answers from different members + of the equivalence set this check must be in a dead + code region. Folding it to a trap representation + would be correct here. For now just return don't-know. */ + if (retval != NULL + && t != retval) + { + retval = NULL_TREE; + break; + } + retval = t; + + if (!sop) + used_strict_overflow = 0; + else if (used_strict_overflow < 0) + used_strict_overflow = 1; + } + } + + if (retval + && used_strict_overflow > 0) + *strict_overflow_p = true; + + return retval; +} + + +/* Given a comparison code COMP and names N1 and N2, compare all the + ranges equivalent to N1 against all the ranges equivalent to N2 + to determine the value of N1 COMP N2. Return the same value + returned by compare_ranges. Set *STRICT_OVERFLOW_P to indicate + whether we relied on an overflow infinity in the comparison. */ + + +static tree +compare_names (enum tree_code comp, tree n1, tree n2, + bool *strict_overflow_p) +{ + tree t, retval; + bitmap e1, e2; + bitmap_iterator bi1, bi2; + unsigned i1, i2; + int used_strict_overflow; + static bitmap_obstack *s_obstack = NULL; + static bitmap s_e1 = NULL, s_e2 = NULL; + + /* Compare the ranges of every name equivalent to N1 against the + ranges of every name equivalent to N2. */ + e1 = get_value_range (n1)->equiv; + e2 = get_value_range (n2)->equiv; + + /* Use the fake bitmaps if e1 or e2 are not available. */ + if (s_obstack == NULL) + { + s_obstack = XNEW (bitmap_obstack); + bitmap_obstack_initialize (s_obstack); + s_e1 = BITMAP_ALLOC (s_obstack); + s_e2 = BITMAP_ALLOC (s_obstack); + } + if (e1 == NULL) + e1 = s_e1; + if (e2 == NULL) + e2 = s_e2; + + /* Add N1 and N2 to their own set of equivalences to avoid + duplicating the body of the loop just to check N1 and N2 + ranges. */ + bitmap_set_bit (e1, SSA_NAME_VERSION (n1)); + bitmap_set_bit (e2, SSA_NAME_VERSION (n2)); + + /* If the equivalence sets have a common intersection, then the two + names can be compared without checking their ranges. */ + if (bitmap_intersect_p (e1, e2)) + { + bitmap_clear_bit (e1, SSA_NAME_VERSION (n1)); + bitmap_clear_bit (e2, SSA_NAME_VERSION (n2)); + + return (comp == EQ_EXPR || comp == GE_EXPR || comp == LE_EXPR) + ? boolean_true_node + : boolean_false_node; + } + + /* Start at -1. Set it to 0 if we do a comparison without relying + on overflow, or 1 if all comparisons rely on overflow. */ + used_strict_overflow = -1; + + /* Otherwise, compare all the equivalent ranges. First, add N1 and + N2 to their own set of equivalences to avoid duplicating the body + of the loop just to check N1 and N2 ranges. */ + EXECUTE_IF_SET_IN_BITMAP (e1, 0, i1, bi1) + { + value_range_t vr1 = get_vr_for_comparison (i1); + + t = retval = NULL_TREE; + EXECUTE_IF_SET_IN_BITMAP (e2, 0, i2, bi2) + { + bool sop = false; + + value_range_t vr2 = get_vr_for_comparison (i2); + + t = compare_ranges (comp, &vr1, &vr2, &sop); + if (t) + { + /* If we get different answers from different members + of the equivalence set this check must be in a dead + code region. Folding it to a trap representation + would be correct here. For now just return don't-know. */ + if (retval != NULL + && t != retval) + { + bitmap_clear_bit (e1, SSA_NAME_VERSION (n1)); + bitmap_clear_bit (e2, SSA_NAME_VERSION (n2)); + return NULL_TREE; + } + retval = t; + + if (!sop) + used_strict_overflow = 0; + else if (used_strict_overflow < 0) + used_strict_overflow = 1; + } + } + + if (retval) + { + bitmap_clear_bit (e1, SSA_NAME_VERSION (n1)); + bitmap_clear_bit (e2, SSA_NAME_VERSION (n2)); + if (used_strict_overflow > 0) + *strict_overflow_p = true; + return retval; + } + } + + /* None of the equivalent ranges are useful in computing this + comparison. */ + bitmap_clear_bit (e1, SSA_NAME_VERSION (n1)); + bitmap_clear_bit (e2, SSA_NAME_VERSION (n2)); + return NULL_TREE; +} + +/* Helper function for vrp_evaluate_conditional_warnv. */ + +static tree +vrp_evaluate_conditional_warnv_with_ops_using_ranges (enum tree_code code, + tree op0, tree op1, + bool * strict_overflow_p) +{ + value_range_t *vr0, *vr1; + + vr0 = (TREE_CODE (op0) == SSA_NAME) ? get_value_range (op0) : NULL; + vr1 = (TREE_CODE (op1) == SSA_NAME) ? get_value_range (op1) : NULL; + + if (vr0 && vr1) + return compare_ranges (code, vr0, vr1, strict_overflow_p); + else if (vr0 && vr1 == NULL) + return compare_range_with_value (code, vr0, op1, strict_overflow_p); + else if (vr0 == NULL && vr1) + return (compare_range_with_value + (swap_tree_comparison (code), vr1, op0, strict_overflow_p)); + return NULL; +} + +/* Helper function for vrp_evaluate_conditional_warnv. */ + +static tree +vrp_evaluate_conditional_warnv_with_ops (enum tree_code code, tree op0, + tree op1, bool use_equiv_p, + bool *strict_overflow_p, bool *only_ranges) +{ + tree ret; + if (only_ranges) + *only_ranges = true; + + /* We only deal with integral and pointer types. */ + if (!INTEGRAL_TYPE_P (TREE_TYPE (op0)) + && !POINTER_TYPE_P (TREE_TYPE (op0))) + return NULL_TREE; + + if (use_equiv_p) + { + if (only_ranges + && (ret = vrp_evaluate_conditional_warnv_with_ops_using_ranges + (code, op0, op1, strict_overflow_p))) + return ret; + *only_ranges = false; + if (TREE_CODE (op0) == SSA_NAME && TREE_CODE (op1) == SSA_NAME) + return compare_names (code, op0, op1, strict_overflow_p); + else if (TREE_CODE (op0) == SSA_NAME) + return compare_name_with_value (code, op0, op1, strict_overflow_p); + else if (TREE_CODE (op1) == SSA_NAME) + return (compare_name_with_value + (swap_tree_comparison (code), op1, op0, strict_overflow_p)); + } + else + return vrp_evaluate_conditional_warnv_with_ops_using_ranges (code, op0, op1, + strict_overflow_p); + return NULL_TREE; +} + +/* Given (CODE OP0 OP1) within STMT, try to simplify it based on value range + information. Return NULL if the conditional can not be evaluated. + The ranges of all the names equivalent with the operands in COND + will be used when trying to compute the value. If the result is + based on undefined signed overflow, issue a warning if + appropriate. */ + +static tree +vrp_evaluate_conditional (enum tree_code code, tree op0, tree op1, gimple stmt) +{ + bool sop; + tree ret; + bool only_ranges; + + /* Some passes and foldings leak constants with overflow flag set + into the IL. Avoid doing wrong things with these and bail out. */ + if ((TREE_CODE (op0) == INTEGER_CST + && TREE_OVERFLOW (op0)) + || (TREE_CODE (op1) == INTEGER_CST + && TREE_OVERFLOW (op1))) + return NULL_TREE; + + sop = false; + ret = vrp_evaluate_conditional_warnv_with_ops (code, op0, op1, true, &sop, + &only_ranges); + + if (ret && sop) + { + enum warn_strict_overflow_code wc; + const char* warnmsg; + + if (is_gimple_min_invariant (ret)) + { + wc = WARN_STRICT_OVERFLOW_CONDITIONAL; + warnmsg = G_("assuming signed overflow does not occur when " + "simplifying conditional to constant"); + } + else + { + wc = WARN_STRICT_OVERFLOW_COMPARISON; + warnmsg = G_("assuming signed overflow does not occur when " + "simplifying conditional"); + } + + if (issue_strict_overflow_warning (wc)) + { + location_t location; + + if (!gimple_has_location (stmt)) + location = input_location; + else + location = gimple_location (stmt); + warning_at (location, OPT_Wstrict_overflow, "%s", warnmsg); + } + } + + if (warn_type_limits + && ret && only_ranges + && TREE_CODE_CLASS (code) == tcc_comparison + && TREE_CODE (op0) == SSA_NAME) + { + /* If the comparison is being folded and the operand on the LHS + is being compared against a constant value that is outside of + the natural range of OP0's type, then the predicate will + always fold regardless of the value of OP0. If -Wtype-limits + was specified, emit a warning. */ + tree type = TREE_TYPE (op0); + value_range_t *vr0 = get_value_range (op0); + + if (vr0->type != VR_VARYING + && INTEGRAL_TYPE_P (type) + && vrp_val_is_min (vr0->min) + && vrp_val_is_max (vr0->max) + && is_gimple_min_invariant (op1)) + { + location_t location; + + if (!gimple_has_location (stmt)) + location = input_location; + else + location = gimple_location (stmt); + + warning_at (location, OPT_Wtype_limits, + integer_zerop (ret) + ? G_("comparison always false " + "due to limited range of data type") + : G_("comparison always true " + "due to limited range of data type")); + } + } + + return ret; +} + + +/* Visit conditional statement STMT. If we can determine which edge + will be taken out of STMT's basic block, record it in + *TAKEN_EDGE_P and return SSA_PROP_INTERESTING. Otherwise, return + SSA_PROP_VARYING. */ + +static enum ssa_prop_result +vrp_visit_cond_stmt (gimple stmt, edge *taken_edge_p) +{ + tree val; + bool sop; + + *taken_edge_p = NULL; + + if (dump_file && (dump_flags & TDF_DETAILS)) + { + tree use; + ssa_op_iter i; + + fprintf (dump_file, "\nVisiting conditional with predicate: "); + print_gimple_stmt (dump_file, stmt, 0, 0); + fprintf (dump_file, "\nWith known ranges\n"); + + FOR_EACH_SSA_TREE_OPERAND (use, stmt, i, SSA_OP_USE) + { + fprintf (dump_file, "\t"); + print_generic_expr (dump_file, use, 0); + fprintf (dump_file, ": "); + dump_value_range (dump_file, vr_value[SSA_NAME_VERSION (use)]); + } + + fprintf (dump_file, "\n"); + } + + /* Compute the value of the predicate COND by checking the known + ranges of each of its operands. + + Note that we cannot evaluate all the equivalent ranges here + because those ranges may not yet be final and with the current + propagation strategy, we cannot determine when the value ranges + of the names in the equivalence set have changed. + + For instance, given the following code fragment + + i_5 = PHI <8, i_13> + ... + i_14 = ASSERT_EXPR <i_5, i_5 != 0> + if (i_14 == 1) + ... + + Assume that on the first visit to i_14, i_5 has the temporary + range [8, 8] because the second argument to the PHI function is + not yet executable. We derive the range ~[0, 0] for i_14 and the + equivalence set { i_5 }. So, when we visit 'if (i_14 == 1)' for + the first time, since i_14 is equivalent to the range [8, 8], we + determine that the predicate is always false. + + On the next round of propagation, i_13 is determined to be + VARYING, which causes i_5 to drop down to VARYING. So, another + visit to i_14 is scheduled. In this second visit, we compute the + exact same range and equivalence set for i_14, namely ~[0, 0] and + { i_5 }. But we did not have the previous range for i_5 + registered, so vrp_visit_assignment thinks that the range for + i_14 has not changed. Therefore, the predicate 'if (i_14 == 1)' + is not visited again, which stops propagation from visiting + statements in the THEN clause of that if(). + + To properly fix this we would need to keep the previous range + value for the names in the equivalence set. This way we would've + discovered that from one visit to the other i_5 changed from + range [8, 8] to VR_VARYING. + + However, fixing this apparent limitation may not be worth the + additional checking. Testing on several code bases (GCC, DLV, + MICO, TRAMP3D and SPEC2000) showed that doing this results in + 4 more predicates folded in SPEC. */ + sop = false; + + val = vrp_evaluate_conditional_warnv_with_ops (gimple_cond_code (stmt), + gimple_cond_lhs (stmt), + gimple_cond_rhs (stmt), + false, &sop, NULL); + if (val) + { + if (!sop) + *taken_edge_p = find_taken_edge (gimple_bb (stmt), val); + else + { + if (dump_file && (dump_flags & TDF_DETAILS)) + fprintf (dump_file, + "\nIgnoring predicate evaluation because " + "it assumes that signed overflow is undefined"); + val = NULL_TREE; + } + } + + if (dump_file && (dump_flags & TDF_DETAILS)) + { + fprintf (dump_file, "\nPredicate evaluates to: "); + if (val == NULL_TREE) + fprintf (dump_file, "DON'T KNOW\n"); + else + print_generic_stmt (dump_file, val, 0); + } + + return (*taken_edge_p) ? SSA_PROP_INTERESTING : SSA_PROP_VARYING; +} + +/* Searches the case label vector VEC for the index *IDX of the CASE_LABEL + that includes the value VAL. The search is restricted to the range + [START_IDX, n - 1] where n is the size of VEC. + + If there is a CASE_LABEL for VAL, its index is placed in IDX and true is + returned. + + If there is no CASE_LABEL for VAL and there is one that is larger than VAL, + it is placed in IDX and false is returned. + + If VAL is larger than any CASE_LABEL, n is placed on IDX and false is + returned. */ + +static bool +find_case_label_index (gimple stmt, size_t start_idx, tree val, size_t *idx) +{ + size_t n = gimple_switch_num_labels (stmt); + size_t low, high; + + /* Find case label for minimum of the value range or the next one. + At each iteration we are searching in [low, high - 1]. */ + + for (low = start_idx, high = n; high != low; ) + { + tree t; + int cmp; + /* Note that i != high, so we never ask for n. */ + size_t i = (high + low) / 2; + t = gimple_switch_label (stmt, i); + + /* Cache the result of comparing CASE_LOW and val. */ + cmp = tree_int_cst_compare (CASE_LOW (t), val); + + if (cmp == 0) + { + /* Ranges cannot be empty. */ + *idx = i; + return true; + } + else if (cmp > 0) + high = i; + else + { + low = i + 1; + if (CASE_HIGH (t) != NULL + && tree_int_cst_compare (CASE_HIGH (t), val) >= 0) + { + *idx = i; + return true; + } + } + } + + *idx = high; + return false; +} + +/* Searches the case label vector VEC for the range of CASE_LABELs that is used + for values between MIN and MAX. The first index is placed in MIN_IDX. The + last index is placed in MAX_IDX. If the range of CASE_LABELs is empty + then MAX_IDX < MIN_IDX. + Returns true if the default label is not needed. */ + +static bool +find_case_label_range (gimple stmt, tree min, tree max, size_t *min_idx, + size_t *max_idx) +{ + size_t i, j; + bool min_take_default = !find_case_label_index (stmt, 1, min, &i); + bool max_take_default = !find_case_label_index (stmt, i, max, &j); + + if (i == j + && min_take_default + && max_take_default) + { + /* Only the default case label reached. + Return an empty range. */ + *min_idx = 1; + *max_idx = 0; + return false; + } + else + { + bool take_default = min_take_default || max_take_default; + tree low, high; + size_t k; + + if (max_take_default) + j--; + + /* If the case label range is continuous, we do not need + the default case label. Verify that. */ + high = CASE_LOW (gimple_switch_label (stmt, i)); + if (CASE_HIGH (gimple_switch_label (stmt, i))) + high = CASE_HIGH (gimple_switch_label (stmt, i)); + for (k = i + 1; k <= j; ++k) + { + low = CASE_LOW (gimple_switch_label (stmt, k)); + if (!integer_onep (int_const_binop (MINUS_EXPR, low, high))) + { + take_default = true; + break; + } + high = low; + if (CASE_HIGH (gimple_switch_label (stmt, k))) + high = CASE_HIGH (gimple_switch_label (stmt, k)); + } + + *min_idx = i; + *max_idx = j; + return !take_default; + } +} + +/* Searches the case label vector VEC for the ranges of CASE_LABELs that are + used in range VR. The indices are placed in MIN_IDX1, MAX_IDX, MIN_IDX2 and + MAX_IDX2. If the ranges of CASE_LABELs are empty then MAX_IDX1 < MIN_IDX1. + Returns true if the default label is not needed. */ + +static bool +find_case_label_ranges (gimple stmt, value_range_t *vr, size_t *min_idx1, + size_t *max_idx1, size_t *min_idx2, + size_t *max_idx2) +{ + size_t i, j, k, l; + unsigned int n = gimple_switch_num_labels (stmt); + bool take_default; + tree case_low, case_high; + tree min = vr->min, max = vr->max; + + gcc_checking_assert (vr->type == VR_RANGE || vr->type == VR_ANTI_RANGE); + + take_default = !find_case_label_range (stmt, min, max, &i, &j); + + /* Set second range to emtpy. */ + *min_idx2 = 1; + *max_idx2 = 0; + + if (vr->type == VR_RANGE) + { + *min_idx1 = i; + *max_idx1 = j; + return !take_default; + } + + /* Set first range to all case labels. */ + *min_idx1 = 1; + *max_idx1 = n - 1; + + if (i > j) + return false; + + /* Make sure all the values of case labels [i , j] are contained in + range [MIN, MAX]. */ + case_low = CASE_LOW (gimple_switch_label (stmt, i)); + case_high = CASE_HIGH (gimple_switch_label (stmt, j)); + if (tree_int_cst_compare (case_low, min) < 0) + i += 1; + if (case_high != NULL_TREE + && tree_int_cst_compare (max, case_high) < 0) + j -= 1; + + if (i > j) + return false; + + /* If the range spans case labels [i, j], the corresponding anti-range spans + the labels [1, i - 1] and [j + 1, n - 1]. */ + k = j + 1; + l = n - 1; + if (k > l) + { + k = 1; + l = 0; + } + + j = i - 1; + i = 1; + if (i > j) + { + i = k; + j = l; + k = 1; + l = 0; + } + + *min_idx1 = i; + *max_idx1 = j; + *min_idx2 = k; + *max_idx2 = l; + return false; +} + +/* Visit switch statement STMT. If we can determine which edge + will be taken out of STMT's basic block, record it in + *TAKEN_EDGE_P and return SSA_PROP_INTERESTING. Otherwise, return + SSA_PROP_VARYING. */ + +static enum ssa_prop_result +vrp_visit_switch_stmt (gimple stmt, edge *taken_edge_p) +{ + tree op, val; + value_range_t *vr; + size_t i = 0, j = 0, k, l; + bool take_default; + + *taken_edge_p = NULL; + op = gimple_switch_index (stmt); + if (TREE_CODE (op) != SSA_NAME) + return SSA_PROP_VARYING; + + vr = get_value_range (op); + if (dump_file && (dump_flags & TDF_DETAILS)) + { + fprintf (dump_file, "\nVisiting switch expression with operand "); + print_generic_expr (dump_file, op, 0); + fprintf (dump_file, " with known range "); + dump_value_range (dump_file, vr); + fprintf (dump_file, "\n"); + } + + if ((vr->type != VR_RANGE + && vr->type != VR_ANTI_RANGE) + || symbolic_range_p (vr)) + return SSA_PROP_VARYING; + + /* Find the single edge that is taken from the switch expression. */ + take_default = !find_case_label_ranges (stmt, vr, &i, &j, &k, &l); + + /* Check if the range spans no CASE_LABEL. If so, we only reach the default + label */ + if (j < i) + { + gcc_assert (take_default); + val = gimple_switch_default_label (stmt); + } + else + { + /* Check if labels with index i to j and maybe the default label + are all reaching the same label. */ + + val = gimple_switch_label (stmt, i); + if (take_default + && CASE_LABEL (gimple_switch_default_label (stmt)) + != CASE_LABEL (val)) + { + if (dump_file && (dump_flags & TDF_DETAILS)) + fprintf (dump_file, " not a single destination for this " + "range\n"); + return SSA_PROP_VARYING; + } + for (++i; i <= j; ++i) + { + if (CASE_LABEL (gimple_switch_label (stmt, i)) != CASE_LABEL (val)) + { + if (dump_file && (dump_flags & TDF_DETAILS)) + fprintf (dump_file, " not a single destination for this " + "range\n"); + return SSA_PROP_VARYING; + } + } + for (; k <= l; ++k) + { + if (CASE_LABEL (gimple_switch_label (stmt, k)) != CASE_LABEL (val)) + { + if (dump_file && (dump_flags & TDF_DETAILS)) + fprintf (dump_file, " not a single destination for this " + "range\n"); + return SSA_PROP_VARYING; + } + } + } + + *taken_edge_p = find_edge (gimple_bb (stmt), + label_to_block (CASE_LABEL (val))); + + if (dump_file && (dump_flags & TDF_DETAILS)) + { + fprintf (dump_file, " will take edge to "); + print_generic_stmt (dump_file, CASE_LABEL (val), 0); + } + + return SSA_PROP_INTERESTING; +} + + +/* Evaluate statement STMT. If the statement produces a useful range, + return SSA_PROP_INTERESTING and record the SSA name with the + interesting range into *OUTPUT_P. + + If STMT is a conditional branch and we can determine its truth + value, the taken edge is recorded in *TAKEN_EDGE_P. + + If STMT produces a varying value, return SSA_PROP_VARYING. */ + +static enum ssa_prop_result +vrp_visit_stmt (gimple stmt, edge *taken_edge_p, tree *output_p) +{ + tree def; + ssa_op_iter iter; + + if (dump_file && (dump_flags & TDF_DETAILS)) + { + fprintf (dump_file, "\nVisiting statement:\n"); + print_gimple_stmt (dump_file, stmt, 0, dump_flags); + fprintf (dump_file, "\n"); + } + + if (!stmt_interesting_for_vrp (stmt)) + gcc_assert (stmt_ends_bb_p (stmt)); + else if (is_gimple_assign (stmt) || is_gimple_call (stmt)) + return vrp_visit_assignment_or_call (stmt, output_p); + else if (gimple_code (stmt) == GIMPLE_COND) + return vrp_visit_cond_stmt (stmt, taken_edge_p); + else if (gimple_code (stmt) == GIMPLE_SWITCH) + return vrp_visit_switch_stmt (stmt, taken_edge_p); + + /* All other statements produce nothing of interest for VRP, so mark + their outputs varying and prevent further simulation. */ + FOR_EACH_SSA_TREE_OPERAND (def, stmt, iter, SSA_OP_DEF) + set_value_range_to_varying (get_value_range (def)); + + return SSA_PROP_VARYING; +} + +/* Union the two value-ranges { *VR0TYPE, *VR0MIN, *VR0MAX } and + { VR1TYPE, VR0MIN, VR0MAX } and store the result + in { *VR0TYPE, *VR0MIN, *VR0MAX }. This may not be the smallest + possible such range. The resulting range is not canonicalized. */ + +static void +union_ranges (enum value_range_type *vr0type, + tree *vr0min, tree *vr0max, + enum value_range_type vr1type, + tree vr1min, tree vr1max) +{ + bool mineq = operand_equal_p (*vr0min, vr1min, 0); + bool maxeq = operand_equal_p (*vr0max, vr1max, 0); + + /* [] is vr0, () is vr1 in the following classification comments. */ + if (mineq && maxeq) + { + /* [( )] */ + if (*vr0type == vr1type) + /* Nothing to do for equal ranges. */ + ; + else if ((*vr0type == VR_RANGE + && vr1type == VR_ANTI_RANGE) + || (*vr0type == VR_ANTI_RANGE + && vr1type == VR_RANGE)) + { + /* For anti-range with range union the result is varying. */ + goto give_up; + } + else + gcc_unreachable (); + } + else if (operand_less_p (*vr0max, vr1min) == 1 + || operand_less_p (vr1max, *vr0min) == 1) + { + /* [ ] ( ) or ( ) [ ] + If the ranges have an empty intersection, result of the union + operation is the anti-range or if both are anti-ranges + it covers all. */ + if (*vr0type == VR_ANTI_RANGE + && vr1type == VR_ANTI_RANGE) + goto give_up; + else if (*vr0type == VR_ANTI_RANGE + && vr1type == VR_RANGE) + ; + else if (*vr0type == VR_RANGE + && vr1type == VR_ANTI_RANGE) + { + *vr0type = vr1type; + *vr0min = vr1min; + *vr0max = vr1max; + } + else if (*vr0type == VR_RANGE + && vr1type == VR_RANGE) + { + /* The result is the convex hull of both ranges. */ + if (operand_less_p (*vr0max, vr1min) == 1) + { + /* If the result can be an anti-range, create one. */ + if (TREE_CODE (*vr0max) == INTEGER_CST + && TREE_CODE (vr1min) == INTEGER_CST + && vrp_val_is_min (*vr0min) + && vrp_val_is_max (vr1max)) + { + tree min = int_const_binop (PLUS_EXPR, + *vr0max, integer_one_node); + tree max = int_const_binop (MINUS_EXPR, + vr1min, integer_one_node); + if (!operand_less_p (max, min)) + { + *vr0type = VR_ANTI_RANGE; + *vr0min = min; + *vr0max = max; + } + else + *vr0max = vr1max; + } + else + *vr0max = vr1max; + } + else + { + /* If the result can be an anti-range, create one. */ + if (TREE_CODE (vr1max) == INTEGER_CST + && TREE_CODE (*vr0min) == INTEGER_CST + && vrp_val_is_min (vr1min) + && vrp_val_is_max (*vr0max)) + { + tree min = int_const_binop (PLUS_EXPR, + vr1max, integer_one_node); + tree max = int_const_binop (MINUS_EXPR, + *vr0min, integer_one_node); + if (!operand_less_p (max, min)) + { + *vr0type = VR_ANTI_RANGE; + *vr0min = min; + *vr0max = max; + } + else + *vr0min = vr1min; + } + else + *vr0min = vr1min; + } + } + else + gcc_unreachable (); + } + else if ((maxeq || operand_less_p (vr1max, *vr0max) == 1) + && (mineq || operand_less_p (*vr0min, vr1min) == 1)) + { + /* [ ( ) ] or [( ) ] or [ ( )] */ + if (*vr0type == VR_RANGE + && vr1type == VR_RANGE) + ; + else if (*vr0type == VR_ANTI_RANGE + && vr1type == VR_ANTI_RANGE) + { + *vr0type = vr1type; + *vr0min = vr1min; + *vr0max = vr1max; + } + else if (*vr0type == VR_ANTI_RANGE + && vr1type == VR_RANGE) + { + /* Arbitrarily choose the right or left gap. */ + if (!mineq && TREE_CODE (vr1min) == INTEGER_CST) + *vr0max = int_const_binop (MINUS_EXPR, vr1min, integer_one_node); + else if (!maxeq && TREE_CODE (vr1max) == INTEGER_CST) + *vr0min = int_const_binop (PLUS_EXPR, vr1max, integer_one_node); + else + goto give_up; + } + else if (*vr0type == VR_RANGE + && vr1type == VR_ANTI_RANGE) + /* The result covers everything. */ + goto give_up; + else + gcc_unreachable (); + } + else if ((maxeq || operand_less_p (*vr0max, vr1max) == 1) + && (mineq || operand_less_p (vr1min, *vr0min) == 1)) + { + /* ( [ ] ) or ([ ] ) or ( [ ]) */ + if (*vr0type == VR_RANGE + && vr1type == VR_RANGE) + { + *vr0type = vr1type; + *vr0min = vr1min; + *vr0max = vr1max; + } + else if (*vr0type == VR_ANTI_RANGE + && vr1type == VR_ANTI_RANGE) + ; + else if (*vr0type == VR_RANGE + && vr1type == VR_ANTI_RANGE) + { + *vr0type = VR_ANTI_RANGE; + if (!mineq && TREE_CODE (*vr0min) == INTEGER_CST) + { + *vr0max = int_const_binop (MINUS_EXPR, *vr0min, integer_one_node); + *vr0min = vr1min; + } + else if (!maxeq && TREE_CODE (*vr0max) == INTEGER_CST) + { + *vr0min = int_const_binop (PLUS_EXPR, *vr0max, integer_one_node); + *vr0max = vr1max; + } + else + goto give_up; + } + else if (*vr0type == VR_ANTI_RANGE + && vr1type == VR_RANGE) + /* The result covers everything. */ + goto give_up; + else + gcc_unreachable (); + } + else if ((operand_less_p (vr1min, *vr0max) == 1 + || operand_equal_p (vr1min, *vr0max, 0)) + && operand_less_p (*vr0min, vr1min) == 1 + && operand_less_p (*vr0max, vr1max) == 1) + { + /* [ ( ] ) or [ ]( ) */ + if (*vr0type == VR_RANGE + && vr1type == VR_RANGE) + *vr0max = vr1max; + else if (*vr0type == VR_ANTI_RANGE + && vr1type == VR_ANTI_RANGE) + *vr0min = vr1min; + else if (*vr0type == VR_ANTI_RANGE + && vr1type == VR_RANGE) + { + if (TREE_CODE (vr1min) == INTEGER_CST) + *vr0max = int_const_binop (MINUS_EXPR, vr1min, integer_one_node); + else + goto give_up; + } + else if (*vr0type == VR_RANGE + && vr1type == VR_ANTI_RANGE) + { + if (TREE_CODE (*vr0max) == INTEGER_CST) + { + *vr0type = vr1type; + *vr0min = int_const_binop (PLUS_EXPR, *vr0max, integer_one_node); + *vr0max = vr1max; + } + else + goto give_up; + } + else + gcc_unreachable (); + } + else if ((operand_less_p (*vr0min, vr1max) == 1 + || operand_equal_p (*vr0min, vr1max, 0)) + && operand_less_p (vr1min, *vr0min) == 1 + && operand_less_p (vr1max, *vr0max) == 1) + { + /* ( [ ) ] or ( )[ ] */ + if (*vr0type == VR_RANGE + && vr1type == VR_RANGE) + *vr0min = vr1min; + else if (*vr0type == VR_ANTI_RANGE + && vr1type == VR_ANTI_RANGE) + *vr0max = vr1max; + else if (*vr0type == VR_ANTI_RANGE + && vr1type == VR_RANGE) + { + if (TREE_CODE (vr1max) == INTEGER_CST) + *vr0min = int_const_binop (PLUS_EXPR, vr1max, integer_one_node); + else + goto give_up; + } + else if (*vr0type == VR_RANGE + && vr1type == VR_ANTI_RANGE) + { + if (TREE_CODE (*vr0min) == INTEGER_CST) + { + *vr0type = vr1type; + *vr0min = vr1min; + *vr0max = int_const_binop (MINUS_EXPR, *vr0min, integer_one_node); + } + else + goto give_up; + } + else + gcc_unreachable (); + } + else + goto give_up; + + return; + +give_up: + *vr0type = VR_VARYING; + *vr0min = NULL_TREE; + *vr0max = NULL_TREE; +} + +/* Intersect the two value-ranges { *VR0TYPE, *VR0MIN, *VR0MAX } and + { VR1TYPE, VR0MIN, VR0MAX } and store the result + in { *VR0TYPE, *VR0MIN, *VR0MAX }. This may not be the smallest + possible such range. The resulting range is not canonicalized. */ + +static void +intersect_ranges (enum value_range_type *vr0type, + tree *vr0min, tree *vr0max, + enum value_range_type vr1type, + tree vr1min, tree vr1max) +{ + bool mineq = operand_equal_p (*vr0min, vr1min, 0); + bool maxeq = operand_equal_p (*vr0max, vr1max, 0); + + /* [] is vr0, () is vr1 in the following classification comments. */ + if (mineq && maxeq) + { + /* [( )] */ + if (*vr0type == vr1type) + /* Nothing to do for equal ranges. */ + ; + else if ((*vr0type == VR_RANGE + && vr1type == VR_ANTI_RANGE) + || (*vr0type == VR_ANTI_RANGE + && vr1type == VR_RANGE)) + { + /* For anti-range with range intersection the result is empty. */ + *vr0type = VR_UNDEFINED; + *vr0min = NULL_TREE; + *vr0max = NULL_TREE; + } + else + gcc_unreachable (); + } + else if (operand_less_p (*vr0max, vr1min) == 1 + || operand_less_p (vr1max, *vr0min) == 1) + { + /* [ ] ( ) or ( ) [ ] + If the ranges have an empty intersection, the result of the + intersect operation is the range for intersecting an + anti-range with a range or empty when intersecting two ranges. */ + if (*vr0type == VR_RANGE + && vr1type == VR_ANTI_RANGE) + ; + else if (*vr0type == VR_ANTI_RANGE + && vr1type == VR_RANGE) + { + *vr0type = vr1type; + *vr0min = vr1min; + *vr0max = vr1max; + } + else if (*vr0type == VR_RANGE + && vr1type == VR_RANGE) + { + *vr0type = VR_UNDEFINED; + *vr0min = NULL_TREE; + *vr0max = NULL_TREE; + } + else if (*vr0type == VR_ANTI_RANGE + && vr1type == VR_ANTI_RANGE) + { + /* If the anti-ranges are adjacent to each other merge them. */ + if (TREE_CODE (*vr0max) == INTEGER_CST + && TREE_CODE (vr1min) == INTEGER_CST + && operand_less_p (*vr0max, vr1min) == 1 + && integer_onep (int_const_binop (MINUS_EXPR, + vr1min, *vr0max))) + *vr0max = vr1max; + else if (TREE_CODE (vr1max) == INTEGER_CST + && TREE_CODE (*vr0min) == INTEGER_CST + && operand_less_p (vr1max, *vr0min) == 1 + && integer_onep (int_const_binop (MINUS_EXPR, + *vr0min, vr1max))) + *vr0min = vr1min; + /* Else arbitrarily take VR0. */ + } + } + else if ((maxeq || operand_less_p (vr1max, *vr0max) == 1) + && (mineq || operand_less_p (*vr0min, vr1min) == 1)) + { + /* [ ( ) ] or [( ) ] or [ ( )] */ + if (*vr0type == VR_RANGE + && vr1type == VR_RANGE) + { + /* If both are ranges the result is the inner one. */ + *vr0type = vr1type; + *vr0min = vr1min; + *vr0max = vr1max; + } + else if (*vr0type == VR_RANGE + && vr1type == VR_ANTI_RANGE) + { + /* Choose the right gap if the left one is empty. */ + if (mineq) + { + if (TREE_CODE (vr1max) == INTEGER_CST) + *vr0min = int_const_binop (PLUS_EXPR, vr1max, integer_one_node); + else + *vr0min = vr1max; + } + /* Choose the left gap if the right one is empty. */ + else if (maxeq) + { + if (TREE_CODE (vr1min) == INTEGER_CST) + *vr0max = int_const_binop (MINUS_EXPR, vr1min, + integer_one_node); + else + *vr0max = vr1min; + } + /* Choose the anti-range if the range is effectively varying. */ + else if (vrp_val_is_min (*vr0min) + && vrp_val_is_max (*vr0max)) + { + *vr0type = vr1type; + *vr0min = vr1min; + *vr0max = vr1max; + } + /* Else choose the range. */ + } + else if (*vr0type == VR_ANTI_RANGE + && vr1type == VR_ANTI_RANGE) + /* If both are anti-ranges the result is the outer one. */ + ; + else if (*vr0type == VR_ANTI_RANGE + && vr1type == VR_RANGE) + { + /* The intersection is empty. */ + *vr0type = VR_UNDEFINED; + *vr0min = NULL_TREE; + *vr0max = NULL_TREE; + } + else + gcc_unreachable (); + } + else if ((maxeq || operand_less_p (*vr0max, vr1max) == 1) + && (mineq || operand_less_p (vr1min, *vr0min) == 1)) + { + /* ( [ ] ) or ([ ] ) or ( [ ]) */ + if (*vr0type == VR_RANGE + && vr1type == VR_RANGE) + /* Choose the inner range. */ + ; + else if (*vr0type == VR_ANTI_RANGE + && vr1type == VR_RANGE) + { + /* Choose the right gap if the left is empty. */ + if (mineq) + { + *vr0type = VR_RANGE; + if (TREE_CODE (*vr0max) == INTEGER_CST) + *vr0min = int_const_binop (PLUS_EXPR, *vr0max, + integer_one_node); + else + *vr0min = *vr0max; + *vr0max = vr1max; + } + /* Choose the left gap if the right is empty. */ + else if (maxeq) + { + *vr0type = VR_RANGE; + if (TREE_CODE (*vr0min) == INTEGER_CST) + *vr0max = int_const_binop (MINUS_EXPR, *vr0min, + integer_one_node); + else + *vr0max = *vr0min; + *vr0min = vr1min; + } + /* Choose the anti-range if the range is effectively varying. */ + else if (vrp_val_is_min (vr1min) + && vrp_val_is_max (vr1max)) + ; + /* Else choose the range. */ + else + { + *vr0type = vr1type; + *vr0min = vr1min; + *vr0max = vr1max; + } + } + else if (*vr0type == VR_ANTI_RANGE + && vr1type == VR_ANTI_RANGE) + { + /* If both are anti-ranges the result is the outer one. */ + *vr0type = vr1type; + *vr0min = vr1min; + *vr0max = vr1max; + } + else if (vr1type == VR_ANTI_RANGE + && *vr0type == VR_RANGE) + { + /* The intersection is empty. */ + *vr0type = VR_UNDEFINED; + *vr0min = NULL_TREE; + *vr0max = NULL_TREE; + } + else + gcc_unreachable (); + } + else if ((operand_less_p (vr1min, *vr0max) == 1 + || operand_equal_p (vr1min, *vr0max, 0)) + && operand_less_p (*vr0min, vr1min) == 1) + { + /* [ ( ] ) or [ ]( ) */ + if (*vr0type == VR_ANTI_RANGE + && vr1type == VR_ANTI_RANGE) + *vr0max = vr1max; + else if (*vr0type == VR_RANGE + && vr1type == VR_RANGE) + *vr0min = vr1min; + else if (*vr0type == VR_RANGE + && vr1type == VR_ANTI_RANGE) + { + if (TREE_CODE (vr1min) == INTEGER_CST) + *vr0max = int_const_binop (MINUS_EXPR, vr1min, + integer_one_node); + else + *vr0max = vr1min; + } + else if (*vr0type == VR_ANTI_RANGE + && vr1type == VR_RANGE) + { + *vr0type = VR_RANGE; + if (TREE_CODE (*vr0max) == INTEGER_CST) + *vr0min = int_const_binop (PLUS_EXPR, *vr0max, + integer_one_node); + else + *vr0min = *vr0max; + *vr0max = vr1max; + } + else + gcc_unreachable (); + } + else if ((operand_less_p (*vr0min, vr1max) == 1 + || operand_equal_p (*vr0min, vr1max, 0)) + && operand_less_p (vr1min, *vr0min) == 1) + { + /* ( [ ) ] or ( )[ ] */ + if (*vr0type == VR_ANTI_RANGE + && vr1type == VR_ANTI_RANGE) + *vr0min = vr1min; + else if (*vr0type == VR_RANGE + && vr1type == VR_RANGE) + *vr0max = vr1max; + else if (*vr0type == VR_RANGE + && vr1type == VR_ANTI_RANGE) + { + if (TREE_CODE (vr1max) == INTEGER_CST) + *vr0min = int_const_binop (PLUS_EXPR, vr1max, + integer_one_node); + else + *vr0min = vr1max; + } + else if (*vr0type == VR_ANTI_RANGE + && vr1type == VR_RANGE) + { + *vr0type = VR_RANGE; + if (TREE_CODE (*vr0min) == INTEGER_CST) + *vr0max = int_const_binop (MINUS_EXPR, *vr0min, + integer_one_node); + else + *vr0max = *vr0min; + *vr0min = vr1min; + } + else + gcc_unreachable (); + } + + /* As a fallback simply use { *VRTYPE, *VR0MIN, *VR0MAX } as + result for the intersection. That's always a conservative + correct estimate. */ + + return; +} + + +/* Intersect the two value-ranges *VR0 and *VR1 and store the result + in *VR0. This may not be the smallest possible such range. */ + +static void +vrp_intersect_ranges_1 (value_range_t *vr0, value_range_t *vr1) +{ + value_range_t saved; + + /* If either range is VR_VARYING the other one wins. */ + if (vr1->type == VR_VARYING) + return; + if (vr0->type == VR_VARYING) + { + copy_value_range (vr0, vr1); + return; + } + + /* When either range is VR_UNDEFINED the resulting range is + VR_UNDEFINED, too. */ + if (vr0->type == VR_UNDEFINED) + return; + if (vr1->type == VR_UNDEFINED) + { + set_value_range_to_undefined (vr0); + return; + } + + /* Save the original vr0 so we can return it as conservative intersection + result when our worker turns things to varying. */ + saved = *vr0; + intersect_ranges (&vr0->type, &vr0->min, &vr0->max, + vr1->type, vr1->min, vr1->max); + /* Make sure to canonicalize the result though as the inversion of a + VR_RANGE can still be a VR_RANGE. */ + set_and_canonicalize_value_range (vr0, vr0->type, + vr0->min, vr0->max, vr0->equiv); + /* If that failed, use the saved original VR0. */ + if (vr0->type == VR_VARYING) + { + *vr0 = saved; + return; + } + /* If the result is VR_UNDEFINED there is no need to mess with + the equivalencies. */ + if (vr0->type == VR_UNDEFINED) + return; + + /* The resulting set of equivalences for range intersection is the union of + the two sets. */ + if (vr0->equiv && vr1->equiv && vr0->equiv != vr1->equiv) + bitmap_ior_into (vr0->equiv, vr1->equiv); + else if (vr1->equiv && !vr0->equiv) + bitmap_copy (vr0->equiv, vr1->equiv); +} + +static void +vrp_intersect_ranges (value_range_t *vr0, value_range_t *vr1) +{ + if (dump_file && (dump_flags & TDF_DETAILS)) + { + fprintf (dump_file, "Intersecting\n "); + dump_value_range (dump_file, vr0); + fprintf (dump_file, "\nand\n "); + dump_value_range (dump_file, vr1); + fprintf (dump_file, "\n"); + } + vrp_intersect_ranges_1 (vr0, vr1); + if (dump_file && (dump_flags & TDF_DETAILS)) + { + fprintf (dump_file, "to\n "); + dump_value_range (dump_file, vr0); + fprintf (dump_file, "\n"); + } +} + +/* Meet operation for value ranges. Given two value ranges VR0 and + VR1, store in VR0 a range that contains both VR0 and VR1. This + may not be the smallest possible such range. */ + +static void +vrp_meet_1 (value_range_t *vr0, value_range_t *vr1) +{ + value_range_t saved; + + if (vr0->type == VR_UNDEFINED) + { + set_value_range (vr0, vr1->type, vr1->min, vr1->max, vr1->equiv); + return; + } + + if (vr1->type == VR_UNDEFINED) + { + /* VR0 already has the resulting range. */ + return; + } + + if (vr0->type == VR_VARYING) + { + /* Nothing to do. VR0 already has the resulting range. */ + return; + } + + if (vr1->type == VR_VARYING) + { + set_value_range_to_varying (vr0); + return; + } + + saved = *vr0; + union_ranges (&vr0->type, &vr0->min, &vr0->max, + vr1->type, vr1->min, vr1->max); + if (vr0->type == VR_VARYING) + { + /* Failed to find an efficient meet. Before giving up and setting + the result to VARYING, see if we can at least derive a useful + anti-range. FIXME, all this nonsense about distinguishing + anti-ranges from ranges is necessary because of the odd + semantics of range_includes_zero_p and friends. */ + if (((saved.type == VR_RANGE + && range_includes_zero_p (saved.min, saved.max) == 0) + || (saved.type == VR_ANTI_RANGE + && range_includes_zero_p (saved.min, saved.max) == 1)) + && ((vr1->type == VR_RANGE + && range_includes_zero_p (vr1->min, vr1->max) == 0) + || (vr1->type == VR_ANTI_RANGE + && range_includes_zero_p (vr1->min, vr1->max) == 1))) + { + set_value_range_to_nonnull (vr0, TREE_TYPE (saved.min)); + + /* Since this meet operation did not result from the meeting of + two equivalent names, VR0 cannot have any equivalences. */ + if (vr0->equiv) + bitmap_clear (vr0->equiv); + return; + } + + set_value_range_to_varying (vr0); + return; + } + set_and_canonicalize_value_range (vr0, vr0->type, vr0->min, vr0->max, + vr0->equiv); + if (vr0->type == VR_VARYING) + return; + + /* The resulting set of equivalences is always the intersection of + the two sets. */ + if (vr0->equiv && vr1->equiv && vr0->equiv != vr1->equiv) + bitmap_and_into (vr0->equiv, vr1->equiv); + else if (vr0->equiv && !vr1->equiv) + bitmap_clear (vr0->equiv); +} + +static void +vrp_meet (value_range_t *vr0, value_range_t *vr1) +{ + if (dump_file && (dump_flags & TDF_DETAILS)) + { + fprintf (dump_file, "Meeting\n "); + dump_value_range (dump_file, vr0); + fprintf (dump_file, "\nand\n "); + dump_value_range (dump_file, vr1); + fprintf (dump_file, "\n"); + } + vrp_meet_1 (vr0, vr1); + if (dump_file && (dump_flags & TDF_DETAILS)) + { + fprintf (dump_file, "to\n "); + dump_value_range (dump_file, vr0); + fprintf (dump_file, "\n"); + } +} + + +/* Visit all arguments for PHI node PHI that flow through executable + edges. If a valid value range can be derived from all the incoming + value ranges, set a new range for the LHS of PHI. */ + +static enum ssa_prop_result +vrp_visit_phi_node (gimple phi) +{ + size_t i; + tree lhs = PHI_RESULT (phi); + value_range_t *lhs_vr = get_value_range (lhs); + value_range_t vr_result = VR_INITIALIZER; + bool first = true; + int edges, old_edges; + struct loop *l; + + if (dump_file && (dump_flags & TDF_DETAILS)) + { + fprintf (dump_file, "\nVisiting PHI node: "); + print_gimple_stmt (dump_file, phi, 0, dump_flags); + } + + edges = 0; + for (i = 0; i < gimple_phi_num_args (phi); i++) + { + edge e = gimple_phi_arg_edge (phi, i); + + if (dump_file && (dump_flags & TDF_DETAILS)) + { + fprintf (dump_file, + "\n Argument #%d (%d -> %d %sexecutable)\n", + (int) i, e->src->index, e->dest->index, + (e->flags & EDGE_EXECUTABLE) ? "" : "not "); + } + + if (e->flags & EDGE_EXECUTABLE) + { + tree arg = PHI_ARG_DEF (phi, i); + value_range_t vr_arg; + + ++edges; + + if (TREE_CODE (arg) == SSA_NAME) + { + vr_arg = *(get_value_range (arg)); + /* Do not allow equivalences or symbolic ranges to leak in from + backedges. That creates invalid equivalencies. + See PR53465 and PR54767. */ + if (e->flags & EDGE_DFS_BACK + && (vr_arg.type == VR_RANGE + || vr_arg.type == VR_ANTI_RANGE)) + { + vr_arg.equiv = NULL; + if (symbolic_range_p (&vr_arg)) + { + vr_arg.type = VR_VARYING; + vr_arg.min = NULL_TREE; + vr_arg.max = NULL_TREE; + } + } + } + else + { + if (TREE_OVERFLOW_P (arg)) + arg = drop_tree_overflow (arg); + + vr_arg.type = VR_RANGE; + vr_arg.min = arg; + vr_arg.max = arg; + vr_arg.equiv = NULL; + } + + if (dump_file && (dump_flags & TDF_DETAILS)) + { + fprintf (dump_file, "\t"); + print_generic_expr (dump_file, arg, dump_flags); + fprintf (dump_file, "\n\tValue: "); + dump_value_range (dump_file, &vr_arg); + fprintf (dump_file, "\n"); + } + + if (first) + copy_value_range (&vr_result, &vr_arg); + else + vrp_meet (&vr_result, &vr_arg); + first = false; + + if (vr_result.type == VR_VARYING) + break; + } + } + + if (vr_result.type == VR_VARYING) + goto varying; + else if (vr_result.type == VR_UNDEFINED) + goto update_range; + + old_edges = vr_phi_edge_counts[SSA_NAME_VERSION (lhs)]; + vr_phi_edge_counts[SSA_NAME_VERSION (lhs)] = edges; + + /* To prevent infinite iterations in the algorithm, derive ranges + when the new value is slightly bigger or smaller than the + previous one. We don't do this if we have seen a new executable + edge; this helps us avoid an overflow infinity for conditionals + which are not in a loop. If the old value-range was VR_UNDEFINED + use the updated range and iterate one more time. */ + if (edges > 0 + && gimple_phi_num_args (phi) > 1 + && edges == old_edges + && lhs_vr->type != VR_UNDEFINED) + { + int cmp_min = compare_values (lhs_vr->min, vr_result.min); + int cmp_max = compare_values (lhs_vr->max, vr_result.max); + + /* For non VR_RANGE or for pointers fall back to varying if + the range changed. */ + if ((lhs_vr->type != VR_RANGE || vr_result.type != VR_RANGE + || POINTER_TYPE_P (TREE_TYPE (lhs))) + && (cmp_min != 0 || cmp_max != 0)) + goto varying; + + /* If the new minimum is smaller or larger than the previous + one, go all the way to -INF. In the first case, to avoid + iterating millions of times to reach -INF, and in the + other case to avoid infinite bouncing between different + minimums. */ + if (cmp_min > 0 || cmp_min < 0) + { + if (!needs_overflow_infinity (TREE_TYPE (vr_result.min)) + || !vrp_var_may_overflow (lhs, phi)) + vr_result.min = TYPE_MIN_VALUE (TREE_TYPE (vr_result.min)); + else if (supports_overflow_infinity (TREE_TYPE (vr_result.min))) + vr_result.min = + negative_overflow_infinity (TREE_TYPE (vr_result.min)); + } + + /* Similarly, if the new maximum is smaller or larger than + the previous one, go all the way to +INF. */ + if (cmp_max < 0 || cmp_max > 0) + { + if (!needs_overflow_infinity (TREE_TYPE (vr_result.max)) + || !vrp_var_may_overflow (lhs, phi)) + vr_result.max = TYPE_MAX_VALUE (TREE_TYPE (vr_result.max)); + else if (supports_overflow_infinity (TREE_TYPE (vr_result.max))) + vr_result.max = + positive_overflow_infinity (TREE_TYPE (vr_result.max)); + } + + /* If we dropped either bound to +-INF then if this is a loop + PHI node SCEV may known more about its value-range. */ + if ((cmp_min > 0 || cmp_min < 0 + || cmp_max < 0 || cmp_max > 0) + && current_loops + && (l = loop_containing_stmt (phi)) + && l->header == gimple_bb (phi)) + adjust_range_with_scev (&vr_result, l, phi, lhs); + + /* If we will end up with a (-INF, +INF) range, set it to + VARYING. Same if the previous max value was invalid for + the type and we end up with vr_result.min > vr_result.max. */ + if ((vrp_val_is_max (vr_result.max) + && vrp_val_is_min (vr_result.min)) + || compare_values (vr_result.min, + vr_result.max) > 0) + goto varying; + } + + /* If the new range is different than the previous value, keep + iterating. */ +update_range: + if (update_value_range (lhs, &vr_result)) + { + if (dump_file && (dump_flags & TDF_DETAILS)) + { + fprintf (dump_file, "Found new range for "); + print_generic_expr (dump_file, lhs, 0); + fprintf (dump_file, ": "); + dump_value_range (dump_file, &vr_result); + fprintf (dump_file, "\n\n"); + } + + return SSA_PROP_INTERESTING; + } + + /* Nothing changed, don't add outgoing edges. */ + return SSA_PROP_NOT_INTERESTING; + + /* No match found. Set the LHS to VARYING. */ +varying: + set_value_range_to_varying (lhs_vr); + return SSA_PROP_VARYING; +} + +/* Simplify boolean operations if the source is known + to be already a boolean. */ +static bool +simplify_truth_ops_using_ranges (gimple_stmt_iterator *gsi, gimple stmt) +{ + enum tree_code rhs_code = gimple_assign_rhs_code (stmt); + tree lhs, op0, op1; + bool need_conversion; + + /* We handle only !=/== case here. */ + gcc_assert (rhs_code == EQ_EXPR || rhs_code == NE_EXPR); + + op0 = gimple_assign_rhs1 (stmt); + if (!op_with_boolean_value_range_p (op0)) + return false; + + op1 = gimple_assign_rhs2 (stmt); + if (!op_with_boolean_value_range_p (op1)) + return false; + + /* Reduce number of cases to handle to NE_EXPR. As there is no + BIT_XNOR_EXPR we cannot replace A == B with a single statement. */ + if (rhs_code == EQ_EXPR) + { + if (TREE_CODE (op1) == INTEGER_CST) + op1 = int_const_binop (BIT_XOR_EXPR, op1, integer_one_node); + else + return false; + } + + lhs = gimple_assign_lhs (stmt); + need_conversion + = !useless_type_conversion_p (TREE_TYPE (lhs), TREE_TYPE (op0)); + + /* Make sure to not sign-extend a 1-bit 1 when converting the result. */ + if (need_conversion + && !TYPE_UNSIGNED (TREE_TYPE (op0)) + && TYPE_PRECISION (TREE_TYPE (op0)) == 1 + && TYPE_PRECISION (TREE_TYPE (lhs)) > 1) + return false; + + /* For A != 0 we can substitute A itself. */ + if (integer_zerop (op1)) + gimple_assign_set_rhs_with_ops (gsi, + need_conversion + ? NOP_EXPR : TREE_CODE (op0), + op0, NULL_TREE); + /* For A != B we substitute A ^ B. Either with conversion. */ + else if (need_conversion) + { + tree tem = make_ssa_name (TREE_TYPE (op0), NULL); + gimple newop = gimple_build_assign_with_ops (BIT_XOR_EXPR, tem, op0, op1); + gsi_insert_before (gsi, newop, GSI_SAME_STMT); + gimple_assign_set_rhs_with_ops (gsi, NOP_EXPR, tem, NULL_TREE); + } + /* Or without. */ + else + gimple_assign_set_rhs_with_ops (gsi, BIT_XOR_EXPR, op0, op1); + update_stmt (gsi_stmt (*gsi)); + + return true; +} + +/* Simplify a division or modulo operator to a right shift or + bitwise and if the first operand is unsigned or is greater + than zero and the second operand is an exact power of two. */ + +static bool +simplify_div_or_mod_using_ranges (gimple stmt) +{ + enum tree_code rhs_code = gimple_assign_rhs_code (stmt); + tree val = NULL; + tree op0 = gimple_assign_rhs1 (stmt); + tree op1 = gimple_assign_rhs2 (stmt); + value_range_t *vr = get_value_range (gimple_assign_rhs1 (stmt)); + + if (TYPE_UNSIGNED (TREE_TYPE (op0))) + { + val = integer_one_node; + } + else + { + bool sop = false; + + val = compare_range_with_value (GE_EXPR, vr, integer_zero_node, &sop); + + if (val + && sop + && integer_onep (val) + && issue_strict_overflow_warning (WARN_STRICT_OVERFLOW_MISC)) + { + location_t location; + + if (!gimple_has_location (stmt)) + location = input_location; + else + location = gimple_location (stmt); + warning_at (location, OPT_Wstrict_overflow, + "assuming signed overflow does not occur when " + "simplifying %</%> or %<%%%> to %<>>%> or %<&%>"); + } + } + + if (val && integer_onep (val)) + { + tree t; + + if (rhs_code == TRUNC_DIV_EXPR) + { + t = build_int_cst (integer_type_node, tree_log2 (op1)); + gimple_assign_set_rhs_code (stmt, RSHIFT_EXPR); + gimple_assign_set_rhs1 (stmt, op0); + gimple_assign_set_rhs2 (stmt, t); + } + else + { + t = build_int_cst (TREE_TYPE (op1), 1); + t = int_const_binop (MINUS_EXPR, op1, t); + t = fold_convert (TREE_TYPE (op0), t); + + gimple_assign_set_rhs_code (stmt, BIT_AND_EXPR); + gimple_assign_set_rhs1 (stmt, op0); + gimple_assign_set_rhs2 (stmt, t); + } + + update_stmt (stmt); + return true; + } + + return false; +} + +/* If the operand to an ABS_EXPR is >= 0, then eliminate the + ABS_EXPR. If the operand is <= 0, then simplify the + ABS_EXPR into a NEGATE_EXPR. */ + +static bool +simplify_abs_using_ranges (gimple stmt) +{ + tree val = NULL; + tree op = gimple_assign_rhs1 (stmt); + tree type = TREE_TYPE (op); + value_range_t *vr = get_value_range (op); + + if (TYPE_UNSIGNED (type)) + { + val = integer_zero_node; + } + else if (vr) + { + bool sop = false; + + val = compare_range_with_value (LE_EXPR, vr, integer_zero_node, &sop); + if (!val) + { + sop = false; + val = compare_range_with_value (GE_EXPR, vr, integer_zero_node, + &sop); + + if (val) + { + if (integer_zerop (val)) + val = integer_one_node; + else if (integer_onep (val)) + val = integer_zero_node; + } + } + + if (val + && (integer_onep (val) || integer_zerop (val))) + { + if (sop && issue_strict_overflow_warning (WARN_STRICT_OVERFLOW_MISC)) + { + location_t location; + + if (!gimple_has_location (stmt)) + location = input_location; + else + location = gimple_location (stmt); + warning_at (location, OPT_Wstrict_overflow, + "assuming signed overflow does not occur when " + "simplifying %<abs (X)%> to %<X%> or %<-X%>"); + } + + gimple_assign_set_rhs1 (stmt, op); + if (integer_onep (val)) + gimple_assign_set_rhs_code (stmt, NEGATE_EXPR); + else + gimple_assign_set_rhs_code (stmt, SSA_NAME); + update_stmt (stmt); + return true; + } + } + + return false; +} + +/* Optimize away redundant BIT_AND_EXPR and BIT_IOR_EXPR. + If all the bits that are being cleared by & are already + known to be zero from VR, or all the bits that are being + set by | are already known to be one from VR, the bit + operation is redundant. */ + +static bool +simplify_bit_ops_using_ranges (gimple_stmt_iterator *gsi, gimple stmt) +{ + tree op0 = gimple_assign_rhs1 (stmt); + tree op1 = gimple_assign_rhs2 (stmt); + tree op = NULL_TREE; + value_range_t vr0 = VR_INITIALIZER; + value_range_t vr1 = VR_INITIALIZER; + double_int may_be_nonzero0, may_be_nonzero1; + double_int must_be_nonzero0, must_be_nonzero1; + double_int mask; + + if (TREE_CODE (op0) == SSA_NAME) + vr0 = *(get_value_range (op0)); + else if (is_gimple_min_invariant (op0)) + set_value_range_to_value (&vr0, op0, NULL); + else + return false; + + if (TREE_CODE (op1) == SSA_NAME) + vr1 = *(get_value_range (op1)); + else if (is_gimple_min_invariant (op1)) + set_value_range_to_value (&vr1, op1, NULL); + else + return false; + + if (!zero_nonzero_bits_from_vr (&vr0, &may_be_nonzero0, &must_be_nonzero0)) + return false; + if (!zero_nonzero_bits_from_vr (&vr1, &may_be_nonzero1, &must_be_nonzero1)) + return false; + + switch (gimple_assign_rhs_code (stmt)) + { + case BIT_AND_EXPR: + mask = may_be_nonzero0.and_not (must_be_nonzero1); + if (mask.is_zero ()) + { + op = op0; + break; + } + mask = may_be_nonzero1.and_not (must_be_nonzero0); + if (mask.is_zero ()) + { + op = op1; + break; + } + break; + case BIT_IOR_EXPR: + mask = may_be_nonzero0.and_not (must_be_nonzero1); + if (mask.is_zero ()) + { + op = op1; + break; + } + mask = may_be_nonzero1.and_not (must_be_nonzero0); + if (mask.is_zero ()) + { + op = op0; + break; + } + break; + default: + gcc_unreachable (); + } + + if (op == NULL_TREE) + return false; + + gimple_assign_set_rhs_with_ops (gsi, TREE_CODE (op), op, NULL); + update_stmt (gsi_stmt (*gsi)); + return true; +} + +/* We are comparing trees OP0 and OP1 using COND_CODE. OP0 has + a known value range VR. + + If there is one and only one value which will satisfy the + conditional, then return that value. Else return NULL. */ + +static tree +test_for_singularity (enum tree_code cond_code, tree op0, + tree op1, value_range_t *vr) +{ + tree min = NULL; + tree max = NULL; + + /* Extract minimum/maximum values which satisfy the + the conditional as it was written. */ + if (cond_code == LE_EXPR || cond_code == LT_EXPR) + { + /* This should not be negative infinity; there is no overflow + here. */ + min = TYPE_MIN_VALUE (TREE_TYPE (op0)); + + max = op1; + if (cond_code == LT_EXPR && !is_overflow_infinity (max)) + { + tree one = build_int_cst (TREE_TYPE (op0), 1); + max = fold_build2 (MINUS_EXPR, TREE_TYPE (op0), max, one); + if (EXPR_P (max)) + TREE_NO_WARNING (max) = 1; + } + } + else if (cond_code == GE_EXPR || cond_code == GT_EXPR) + { + /* This should not be positive infinity; there is no overflow + here. */ + max = TYPE_MAX_VALUE (TREE_TYPE (op0)); + + min = op1; + if (cond_code == GT_EXPR && !is_overflow_infinity (min)) + { + tree one = build_int_cst (TREE_TYPE (op0), 1); + min = fold_build2 (PLUS_EXPR, TREE_TYPE (op0), min, one); + if (EXPR_P (min)) + TREE_NO_WARNING (min) = 1; + } + } + + /* Now refine the minimum and maximum values using any + value range information we have for op0. */ + if (min && max) + { + if (compare_values (vr->min, min) == 1) + min = vr->min; + if (compare_values (vr->max, max) == -1) + max = vr->max; + + /* If the new min/max values have converged to a single value, + then there is only one value which can satisfy the condition, + return that value. */ + if (operand_equal_p (min, max, 0) && is_gimple_min_invariant (min)) + return min; + } + return NULL; +} + +/* Return whether the value range *VR fits in an integer type specified + by PRECISION and UNSIGNED_P. */ + +static bool +range_fits_type_p (value_range_t *vr, unsigned precision, bool unsigned_p) +{ + tree src_type; + unsigned src_precision; + double_int tem; + + /* We can only handle integral and pointer types. */ + src_type = TREE_TYPE (vr->min); + if (!INTEGRAL_TYPE_P (src_type) + && !POINTER_TYPE_P (src_type)) + return false; + + /* An extension is fine unless VR is signed and unsigned_p, + and so is an identity transform. */ + src_precision = TYPE_PRECISION (TREE_TYPE (vr->min)); + if ((src_precision < precision + && !(unsigned_p && !TYPE_UNSIGNED (src_type))) + || (src_precision == precision + && TYPE_UNSIGNED (src_type) == unsigned_p)) + return true; + + /* Now we can only handle ranges with constant bounds. */ + if (vr->type != VR_RANGE + || TREE_CODE (vr->min) != INTEGER_CST + || TREE_CODE (vr->max) != INTEGER_CST) + return false; + + /* For sign changes, the MSB of the double_int has to be clear. + An unsigned value with its MSB set cannot be represented by + a signed double_int, while a negative value cannot be represented + by an unsigned double_int. */ + if (TYPE_UNSIGNED (src_type) != unsigned_p + && (TREE_INT_CST_HIGH (vr->min) | TREE_INT_CST_HIGH (vr->max)) < 0) + return false; + + /* Then we can perform the conversion on both ends and compare + the result for equality. */ + tem = tree_to_double_int (vr->min).ext (precision, unsigned_p); + if (tree_to_double_int (vr->min) != tem) + return false; + tem = tree_to_double_int (vr->max).ext (precision, unsigned_p); + if (tree_to_double_int (vr->max) != tem) + return false; + + return true; +} + +/* Simplify a conditional using a relational operator to an equality + test if the range information indicates only one value can satisfy + the original conditional. */ + +static bool +simplify_cond_using_ranges (gimple stmt) +{ + tree op0 = gimple_cond_lhs (stmt); + tree op1 = gimple_cond_rhs (stmt); + enum tree_code cond_code = gimple_cond_code (stmt); + + if (cond_code != NE_EXPR + && cond_code != EQ_EXPR + && TREE_CODE (op0) == SSA_NAME + && INTEGRAL_TYPE_P (TREE_TYPE (op0)) + && is_gimple_min_invariant (op1)) + { + value_range_t *vr = get_value_range (op0); + + /* If we have range information for OP0, then we might be + able to simplify this conditional. */ + if (vr->type == VR_RANGE) + { + tree new_tree = test_for_singularity (cond_code, op0, op1, vr); + + if (new_tree) + { + if (dump_file) + { + fprintf (dump_file, "Simplified relational "); + print_gimple_stmt (dump_file, stmt, 0, 0); + fprintf (dump_file, " into "); + } + + gimple_cond_set_code (stmt, EQ_EXPR); + gimple_cond_set_lhs (stmt, op0); + gimple_cond_set_rhs (stmt, new_tree); + + update_stmt (stmt); + + if (dump_file) + { + print_gimple_stmt (dump_file, stmt, 0, 0); + fprintf (dump_file, "\n"); + } + + return true; + } + + /* Try again after inverting the condition. We only deal + with integral types here, so no need to worry about + issues with inverting FP comparisons. */ + cond_code = invert_tree_comparison (cond_code, false); + new_tree = test_for_singularity (cond_code, op0, op1, vr); + + if (new_tree) + { + if (dump_file) + { + fprintf (dump_file, "Simplified relational "); + print_gimple_stmt (dump_file, stmt, 0, 0); + fprintf (dump_file, " into "); + } + + gimple_cond_set_code (stmt, NE_EXPR); + gimple_cond_set_lhs (stmt, op0); + gimple_cond_set_rhs (stmt, new_tree); + + update_stmt (stmt); + + if (dump_file) + { + print_gimple_stmt (dump_file, stmt, 0, 0); + fprintf (dump_file, "\n"); + } + + return true; + } + } + } + + /* If we have a comparison of an SSA_NAME (OP0) against a constant, + see if OP0 was set by a type conversion where the source of + the conversion is another SSA_NAME with a range that fits + into the range of OP0's type. + + If so, the conversion is redundant as the earlier SSA_NAME can be + used for the comparison directly if we just massage the constant in the + comparison. */ + if (TREE_CODE (op0) == SSA_NAME + && TREE_CODE (op1) == INTEGER_CST) + { + gimple def_stmt = SSA_NAME_DEF_STMT (op0); + tree innerop; + + if (!is_gimple_assign (def_stmt) + || !CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (def_stmt))) + return false; + + innerop = gimple_assign_rhs1 (def_stmt); + + if (TREE_CODE (innerop) == SSA_NAME + && !POINTER_TYPE_P (TREE_TYPE (innerop))) + { + value_range_t *vr = get_value_range (innerop); + + if (range_int_cst_p (vr) + && range_fits_type_p (vr, + TYPE_PRECISION (TREE_TYPE (op0)), + TYPE_UNSIGNED (TREE_TYPE (op0))) + && int_fits_type_p (op1, TREE_TYPE (innerop)) + /* The range must not have overflowed, or if it did overflow + we must not be wrapping/trapping overflow and optimizing + with strict overflow semantics. */ + && ((!is_negative_overflow_infinity (vr->min) + && !is_positive_overflow_infinity (vr->max)) + || TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (innerop)))) + { + /* If the range overflowed and the user has asked for warnings + when strict overflow semantics were used to optimize code, + issue an appropriate warning. */ + if ((is_negative_overflow_infinity (vr->min) + || is_positive_overflow_infinity (vr->max)) + && issue_strict_overflow_warning (WARN_STRICT_OVERFLOW_CONDITIONAL)) + { + location_t location; + + if (!gimple_has_location (stmt)) + location = input_location; + else + location = gimple_location (stmt); + warning_at (location, OPT_Wstrict_overflow, + "assuming signed overflow does not occur when " + "simplifying conditional"); + } + + tree newconst = fold_convert (TREE_TYPE (innerop), op1); + gimple_cond_set_lhs (stmt, innerop); + gimple_cond_set_rhs (stmt, newconst); + return true; + } + } + } + + return false; +} + +/* Simplify a switch statement using the value range of the switch + argument. */ + +static bool +simplify_switch_using_ranges (gimple stmt) +{ + tree op = gimple_switch_index (stmt); + value_range_t *vr; + bool take_default; + edge e; + edge_iterator ei; + size_t i = 0, j = 0, n, n2; + tree vec2; + switch_update su; + size_t k = 1, l = 0; + + if (TREE_CODE (op) == SSA_NAME) + { + vr = get_value_range (op); + + /* We can only handle integer ranges. */ + if ((vr->type != VR_RANGE + && vr->type != VR_ANTI_RANGE) + || symbolic_range_p (vr)) + return false; + + /* Find case label for min/max of the value range. */ + take_default = !find_case_label_ranges (stmt, vr, &i, &j, &k, &l); + } + else if (TREE_CODE (op) == INTEGER_CST) + { + take_default = !find_case_label_index (stmt, 1, op, &i); + if (take_default) + { + i = 1; + j = 0; + } + else + { + j = i; + } + } + else + return false; + + n = gimple_switch_num_labels (stmt); + + /* Bail out if this is just all edges taken. */ + if (i == 1 + && j == n - 1 + && take_default) + return false; + + /* Build a new vector of taken case labels. */ + vec2 = make_tree_vec (j - i + 1 + l - k + 1 + (int)take_default); + n2 = 0; + + /* Add the default edge, if necessary. */ + if (take_default) + TREE_VEC_ELT (vec2, n2++) = gimple_switch_default_label (stmt); + + for (; i <= j; ++i, ++n2) + TREE_VEC_ELT (vec2, n2) = gimple_switch_label (stmt, i); + + for (; k <= l; ++k, ++n2) + TREE_VEC_ELT (vec2, n2) = gimple_switch_label (stmt, k); + + /* Mark needed edges. */ + for (i = 0; i < n2; ++i) + { + e = find_edge (gimple_bb (stmt), + label_to_block (CASE_LABEL (TREE_VEC_ELT (vec2, i)))); + e->aux = (void *)-1; + } + + /* Queue not needed edges for later removal. */ + FOR_EACH_EDGE (e, ei, gimple_bb (stmt)->succs) + { + if (e->aux == (void *)-1) + { + e->aux = NULL; + continue; + } + + if (dump_file && (dump_flags & TDF_DETAILS)) + { + fprintf (dump_file, "removing unreachable case label\n"); + } + to_remove_edges.safe_push (e); + e->flags &= ~EDGE_EXECUTABLE; + } + + /* And queue an update for the stmt. */ + su.stmt = stmt; + su.vec = vec2; + to_update_switch_stmts.safe_push (su); + return false; +} + +/* Simplify an integral conversion from an SSA name in STMT. */ + +static bool +simplify_conversion_using_ranges (gimple stmt) +{ + tree innerop, middleop, finaltype; + gimple def_stmt; + value_range_t *innervr; + bool inner_unsigned_p, middle_unsigned_p, final_unsigned_p; + unsigned inner_prec, middle_prec, final_prec; + double_int innermin, innermed, innermax, middlemin, middlemed, middlemax; + + finaltype = TREE_TYPE (gimple_assign_lhs (stmt)); + if (!INTEGRAL_TYPE_P (finaltype)) + return false; + middleop = gimple_assign_rhs1 (stmt); + def_stmt = SSA_NAME_DEF_STMT (middleop); + if (!is_gimple_assign (def_stmt) + || !CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (def_stmt))) + return false; + innerop = gimple_assign_rhs1 (def_stmt); + if (TREE_CODE (innerop) != SSA_NAME + || SSA_NAME_OCCURS_IN_ABNORMAL_PHI (innerop)) + return false; + + /* Get the value-range of the inner operand. */ + innervr = get_value_range (innerop); + if (innervr->type != VR_RANGE + || TREE_CODE (innervr->min) != INTEGER_CST + || TREE_CODE (innervr->max) != INTEGER_CST) + return false; + + /* Simulate the conversion chain to check if the result is equal if + the middle conversion is removed. */ + innermin = tree_to_double_int (innervr->min); + innermax = tree_to_double_int (innervr->max); + + inner_prec = TYPE_PRECISION (TREE_TYPE (innerop)); + middle_prec = TYPE_PRECISION (TREE_TYPE (middleop)); + final_prec = TYPE_PRECISION (finaltype); + + /* If the first conversion is not injective, the second must not + be widening. */ + if ((innermax - innermin).ugt (double_int::mask (middle_prec)) + && middle_prec < final_prec) + return false; + /* We also want a medium value so that we can track the effect that + narrowing conversions with sign change have. */ + inner_unsigned_p = TYPE_UNSIGNED (TREE_TYPE (innerop)); + if (inner_unsigned_p) + innermed = double_int::mask (inner_prec).lrshift (1, inner_prec); + else + innermed = double_int_zero; + if (innermin.cmp (innermed, inner_unsigned_p) >= 0 + || innermed.cmp (innermax, inner_unsigned_p) >= 0) + innermed = innermin; + + middle_unsigned_p = TYPE_UNSIGNED (TREE_TYPE (middleop)); + middlemin = innermin.ext (middle_prec, middle_unsigned_p); + middlemed = innermed.ext (middle_prec, middle_unsigned_p); + middlemax = innermax.ext (middle_prec, middle_unsigned_p); + + /* Require that the final conversion applied to both the original + and the intermediate range produces the same result. */ + final_unsigned_p = TYPE_UNSIGNED (finaltype); + if (middlemin.ext (final_prec, final_unsigned_p) + != innermin.ext (final_prec, final_unsigned_p) + || middlemed.ext (final_prec, final_unsigned_p) + != innermed.ext (final_prec, final_unsigned_p) + || middlemax.ext (final_prec, final_unsigned_p) + != innermax.ext (final_prec, final_unsigned_p)) + return false; + + gimple_assign_set_rhs1 (stmt, innerop); + update_stmt (stmt); + return true; +} + +/* Simplify a conversion from integral SSA name to float in STMT. */ + +static bool +simplify_float_conversion_using_ranges (gimple_stmt_iterator *gsi, gimple stmt) +{ + tree rhs1 = gimple_assign_rhs1 (stmt); + value_range_t *vr = get_value_range (rhs1); + enum machine_mode fltmode = TYPE_MODE (TREE_TYPE (gimple_assign_lhs (stmt))); + enum machine_mode mode; + tree tem; + gimple conv; + + /* We can only handle constant ranges. */ + if (vr->type != VR_RANGE + || TREE_CODE (vr->min) != INTEGER_CST + || TREE_CODE (vr->max) != INTEGER_CST) + return false; + + /* First check if we can use a signed type in place of an unsigned. */ + if (TYPE_UNSIGNED (TREE_TYPE (rhs1)) + && (can_float_p (fltmode, TYPE_MODE (TREE_TYPE (rhs1)), 0) + != CODE_FOR_nothing) + && range_fits_type_p (vr, GET_MODE_PRECISION + (TYPE_MODE (TREE_TYPE (rhs1))), 0)) + mode = TYPE_MODE (TREE_TYPE (rhs1)); + /* If we can do the conversion in the current input mode do nothing. */ + else if (can_float_p (fltmode, TYPE_MODE (TREE_TYPE (rhs1)), + TYPE_UNSIGNED (TREE_TYPE (rhs1))) != CODE_FOR_nothing) + return false; + /* Otherwise search for a mode we can use, starting from the narrowest + integer mode available. */ + else + { + mode = GET_CLASS_NARROWEST_MODE (MODE_INT); + do + { + /* If we cannot do a signed conversion to float from mode + or if the value-range does not fit in the signed type + try with a wider mode. */ + if (can_float_p (fltmode, mode, 0) != CODE_FOR_nothing + && range_fits_type_p (vr, GET_MODE_PRECISION (mode), 0)) + break; + + mode = GET_MODE_WIDER_MODE (mode); + /* But do not widen the input. Instead leave that to the + optabs expansion code. */ + if (GET_MODE_PRECISION (mode) > TYPE_PRECISION (TREE_TYPE (rhs1))) + return false; + } + while (mode != VOIDmode); + if (mode == VOIDmode) + return false; + } + + /* It works, insert a truncation or sign-change before the + float conversion. */ + tem = make_ssa_name (build_nonstandard_integer_type + (GET_MODE_PRECISION (mode), 0), NULL); + conv = gimple_build_assign_with_ops (NOP_EXPR, tem, rhs1, NULL_TREE); + gsi_insert_before (gsi, conv, GSI_SAME_STMT); + gimple_assign_set_rhs1 (stmt, tem); + update_stmt (stmt); + + return true; +} + +/* Simplify an internal fn call using ranges if possible. */ + +static bool +simplify_internal_call_using_ranges (gimple_stmt_iterator *gsi, gimple stmt) +{ + enum tree_code subcode; + switch (gimple_call_internal_fn (stmt)) + { + case IFN_UBSAN_CHECK_ADD: + subcode = PLUS_EXPR; + break; + case IFN_UBSAN_CHECK_SUB: + subcode = MINUS_EXPR; + break; + case IFN_UBSAN_CHECK_MUL: + subcode = MULT_EXPR; + break; + default: + return false; + } + + value_range_t vr0 = VR_INITIALIZER; + value_range_t vr1 = VR_INITIALIZER; + tree op0 = gimple_call_arg (stmt, 0); + tree op1 = gimple_call_arg (stmt, 1); + + if (TREE_CODE (op0) == SSA_NAME) + vr0 = *get_value_range (op0); + else if (TREE_CODE (op0) == INTEGER_CST) + set_value_range_to_value (&vr0, op0, NULL); + else + return false; + + if (TREE_CODE (op1) == SSA_NAME) + vr1 = *get_value_range (op1); + else if (TREE_CODE (op1) == INTEGER_CST) + set_value_range_to_value (&vr1, op1, NULL); + else + return false; + + if (!range_int_cst_p (&vr0) || !range_int_cst_p (&vr1)) + return false; + + tree r1 = int_const_binop (subcode, vr0.min, vr1.min); + tree r2 = int_const_binop (subcode, vr0.max, vr1.max); + if (r1 == NULL_TREE || TREE_OVERFLOW (r1) + || r2 == NULL_TREE || TREE_OVERFLOW (r2)) + return false; + if (subcode == MULT_EXPR) + { + tree r3 = int_const_binop (subcode, vr0.min, vr1.max); + tree r4 = int_const_binop (subcode, vr0.max, vr1.min); + if (r3 == NULL_TREE || TREE_OVERFLOW (r3) + || r4 == NULL_TREE || TREE_OVERFLOW (r4)) + return false; + } + gimple g = gimple_build_assign_with_ops (subcode, gimple_call_lhs (stmt), + op0, op1); + gsi_replace (gsi, g, false); + return true; +} + +/* Simplify STMT using ranges if possible. */ + +static bool +simplify_stmt_using_ranges (gimple_stmt_iterator *gsi) +{ + gimple stmt = gsi_stmt (*gsi); + if (is_gimple_assign (stmt)) + { + enum tree_code rhs_code = gimple_assign_rhs_code (stmt); + tree rhs1 = gimple_assign_rhs1 (stmt); + + switch (rhs_code) + { + case EQ_EXPR: + case NE_EXPR: + /* Transform EQ_EXPR, NE_EXPR into BIT_XOR_EXPR or identity + if the RHS is zero or one, and the LHS are known to be boolean + values. */ + if (INTEGRAL_TYPE_P (TREE_TYPE (rhs1))) + return simplify_truth_ops_using_ranges (gsi, stmt); + break; + + /* Transform TRUNC_DIV_EXPR and TRUNC_MOD_EXPR into RSHIFT_EXPR + and BIT_AND_EXPR respectively if the first operand is greater + than zero and the second operand is an exact power of two. */ + case TRUNC_DIV_EXPR: + case TRUNC_MOD_EXPR: + if (INTEGRAL_TYPE_P (TREE_TYPE (rhs1)) + && integer_pow2p (gimple_assign_rhs2 (stmt))) + return simplify_div_or_mod_using_ranges (stmt); + break; + + /* Transform ABS (X) into X or -X as appropriate. */ + case ABS_EXPR: + if (TREE_CODE (rhs1) == SSA_NAME + && INTEGRAL_TYPE_P (TREE_TYPE (rhs1))) + return simplify_abs_using_ranges (stmt); + break; + + case BIT_AND_EXPR: + case BIT_IOR_EXPR: + /* Optimize away BIT_AND_EXPR and BIT_IOR_EXPR + if all the bits being cleared are already cleared or + all the bits being set are already set. */ + if (INTEGRAL_TYPE_P (TREE_TYPE (rhs1))) + return simplify_bit_ops_using_ranges (gsi, stmt); + break; + + CASE_CONVERT: + if (TREE_CODE (rhs1) == SSA_NAME + && INTEGRAL_TYPE_P (TREE_TYPE (rhs1))) + return simplify_conversion_using_ranges (stmt); + break; + + case FLOAT_EXPR: + if (TREE_CODE (rhs1) == SSA_NAME + && INTEGRAL_TYPE_P (TREE_TYPE (rhs1))) + return simplify_float_conversion_using_ranges (gsi, stmt); + break; + + default: + break; + } + } + else if (gimple_code (stmt) == GIMPLE_COND) + return simplify_cond_using_ranges (stmt); + else if (gimple_code (stmt) == GIMPLE_SWITCH) + return simplify_switch_using_ranges (stmt); + else if (is_gimple_call (stmt) + && gimple_call_internal_p (stmt)) + return simplify_internal_call_using_ranges (gsi, stmt); + + return false; +} + +/* If the statement pointed by SI has a predicate whose value can be + computed using the value range information computed by VRP, compute + its value and return true. Otherwise, return false. */ + +static bool +fold_predicate_in (gimple_stmt_iterator *si) +{ + bool assignment_p = false; + tree val; + gimple stmt = gsi_stmt (*si); + + if (is_gimple_assign (stmt) + && TREE_CODE_CLASS (gimple_assign_rhs_code (stmt)) == tcc_comparison) + { + assignment_p = true; + val = vrp_evaluate_conditional (gimple_assign_rhs_code (stmt), + gimple_assign_rhs1 (stmt), + gimple_assign_rhs2 (stmt), + stmt); + } + else if (gimple_code (stmt) == GIMPLE_COND) + val = vrp_evaluate_conditional (gimple_cond_code (stmt), + gimple_cond_lhs (stmt), + gimple_cond_rhs (stmt), + stmt); + else + return false; + + if (val) + { + if (assignment_p) + val = fold_convert (gimple_expr_type (stmt), val); + + if (dump_file) + { + fprintf (dump_file, "Folding predicate "); + print_gimple_expr (dump_file, stmt, 0, 0); + fprintf (dump_file, " to "); + print_generic_expr (dump_file, val, 0); + fprintf (dump_file, "\n"); + } + + if (is_gimple_assign (stmt)) + gimple_assign_set_rhs_from_tree (si, val); + else + { + gcc_assert (gimple_code (stmt) == GIMPLE_COND); + if (integer_zerop (val)) + gimple_cond_make_false (stmt); + else if (integer_onep (val)) + gimple_cond_make_true (stmt); + else + gcc_unreachable (); + } + + return true; + } + + return false; +} + +/* Callback for substitute_and_fold folding the stmt at *SI. */ + +static bool +vrp_fold_stmt (gimple_stmt_iterator *si) +{ + if (fold_predicate_in (si)) + return true; + + return simplify_stmt_using_ranges (si); +} + +/* Stack of dest,src equivalency pairs that need to be restored after + each attempt to thread a block's incoming edge to an outgoing edge. + + A NULL entry is used to mark the end of pairs which need to be + restored. */ +static vec<tree> equiv_stack; + +/* A trivial wrapper so that we can present the generic jump threading + code with a simple API for simplifying statements. STMT is the + statement we want to simplify, WITHIN_STMT provides the location + for any overflow warnings. */ + +static tree +simplify_stmt_for_jump_threading (gimple stmt, gimple within_stmt) +{ + if (gimple_code (stmt) == GIMPLE_COND) + return vrp_evaluate_conditional (gimple_cond_code (stmt), + gimple_cond_lhs (stmt), + gimple_cond_rhs (stmt), within_stmt); + + if (gimple_code (stmt) == GIMPLE_ASSIGN) + { + value_range_t new_vr = VR_INITIALIZER; + tree lhs = gimple_assign_lhs (stmt); + + if (TREE_CODE (lhs) == SSA_NAME + && (INTEGRAL_TYPE_P (TREE_TYPE (lhs)) + || POINTER_TYPE_P (TREE_TYPE (lhs)))) + { + extract_range_from_assignment (&new_vr, stmt); + if (range_int_cst_singleton_p (&new_vr)) + return new_vr.min; + } + } + + return NULL_TREE; +} + +/* Blocks which have more than one predecessor and more than + one successor present jump threading opportunities, i.e., + when the block is reached from a specific predecessor, we + may be able to determine which of the outgoing edges will + be traversed. When this optimization applies, we are able + to avoid conditionals at runtime and we may expose secondary + optimization opportunities. + + This routine is effectively a driver for the generic jump + threading code. It basically just presents the generic code + with edges that may be suitable for jump threading. + + Unlike DOM, we do not iterate VRP if jump threading was successful. + While iterating may expose new opportunities for VRP, it is expected + those opportunities would be very limited and the compile time cost + to expose those opportunities would be significant. + + As jump threading opportunities are discovered, they are registered + for later realization. */ + +static void +identify_jump_threads (void) +{ + basic_block bb; + gimple dummy; + int i; + edge e; + + /* Ugh. When substituting values earlier in this pass we can + wipe the dominance information. So rebuild the dominator + information as we need it within the jump threading code. */ + calculate_dominance_info (CDI_DOMINATORS); + + /* We do not allow VRP information to be used for jump threading + across a back edge in the CFG. Otherwise it becomes too + difficult to avoid eliminating loop exit tests. Of course + EDGE_DFS_BACK is not accurate at this time so we have to + recompute it. */ + mark_dfs_back_edges (); + + /* Do not thread across edges we are about to remove. Just marking + them as EDGE_DFS_BACK will do. */ + FOR_EACH_VEC_ELT (to_remove_edges, i, e) + e->flags |= EDGE_DFS_BACK; + + /* Allocate our unwinder stack to unwind any temporary equivalences + that might be recorded. */ + equiv_stack.create (20); + + /* To avoid lots of silly node creation, we create a single + conditional and just modify it in-place when attempting to + thread jumps. */ + dummy = gimple_build_cond (EQ_EXPR, + integer_zero_node, integer_zero_node, + NULL, NULL); + + /* Walk through all the blocks finding those which present a + potential jump threading opportunity. We could set this up + as a dominator walker and record data during the walk, but + I doubt it's worth the effort for the classes of jump + threading opportunities we are trying to identify at this + point in compilation. */ + FOR_EACH_BB_FN (bb, cfun) + { + gimple last; + + /* If the generic jump threading code does not find this block + interesting, then there is nothing to do. */ + if (! potentially_threadable_block (bb)) + continue; + + /* We only care about blocks ending in a COND_EXPR. While there + may be some value in handling SWITCH_EXPR here, I doubt it's + terribly important. */ + last = gsi_stmt (gsi_last_bb (bb)); + + /* We're basically looking for a switch or any kind of conditional with + integral or pointer type arguments. Note the type of the second + argument will be the same as the first argument, so no need to + check it explicitly. */ + if (gimple_code (last) == GIMPLE_SWITCH + || (gimple_code (last) == GIMPLE_COND + && TREE_CODE (gimple_cond_lhs (last)) == SSA_NAME + && (INTEGRAL_TYPE_P (TREE_TYPE (gimple_cond_lhs (last))) + || POINTER_TYPE_P (TREE_TYPE (gimple_cond_lhs (last)))) + && (TREE_CODE (gimple_cond_rhs (last)) == SSA_NAME + || is_gimple_min_invariant (gimple_cond_rhs (last))))) + { + edge_iterator ei; + + /* We've got a block with multiple predecessors and multiple + successors which also ends in a suitable conditional or + switch statement. For each predecessor, see if we can thread + it to a specific successor. */ + FOR_EACH_EDGE (e, ei, bb->preds) + { + /* Do not thread across back edges or abnormal edges + in the CFG. */ + if (e->flags & (EDGE_DFS_BACK | EDGE_COMPLEX)) + continue; + + thread_across_edge (dummy, e, true, &equiv_stack, + simplify_stmt_for_jump_threading); + } + } + } + + /* We do not actually update the CFG or SSA graphs at this point as + ASSERT_EXPRs are still in the IL and cfg cleanup code does not yet + handle ASSERT_EXPRs gracefully. */ +} + +/* We identified all the jump threading opportunities earlier, but could + not transform the CFG at that time. This routine transforms the + CFG and arranges for the dominator tree to be rebuilt if necessary. + + Note the SSA graph update will occur during the normal TODO + processing by the pass manager. */ +static void +finalize_jump_threads (void) +{ + thread_through_all_blocks (false); + equiv_stack.release (); +} + + +/* Traverse all the blocks folding conditionals with known ranges. */ + +static void +vrp_finalize (void) +{ + size_t i; + + values_propagated = true; + + if (dump_file) + { + fprintf (dump_file, "\nValue ranges after VRP:\n\n"); + dump_all_value_ranges (dump_file); + fprintf (dump_file, "\n"); + } + + substitute_and_fold (op_with_constant_singleton_value_range, + vrp_fold_stmt, false); + + if (warn_array_bounds) + check_all_array_refs (); + + /* We must identify jump threading opportunities before we release + the datastructures built by VRP. */ + identify_jump_threads (); + + /* Set value range to non pointer SSA_NAMEs. */ + for (i = 0; i < num_vr_values; i++) + if (vr_value[i]) + { + tree name = ssa_name (i); + + if (!name + || POINTER_TYPE_P (TREE_TYPE (name)) + || (vr_value[i]->type == VR_VARYING) + || (vr_value[i]->type == VR_UNDEFINED)) + continue; + + if ((TREE_CODE (vr_value[i]->min) == INTEGER_CST) + && (TREE_CODE (vr_value[i]->max) == INTEGER_CST) + && (vr_value[i]->type == VR_RANGE + || vr_value[i]->type == VR_ANTI_RANGE)) + set_range_info (name, vr_value[i]->type, + tree_to_double_int (vr_value[i]->min), + tree_to_double_int (vr_value[i]->max)); + } + + /* Free allocated memory. */ + for (i = 0; i < num_vr_values; i++) + if (vr_value[i]) + { + BITMAP_FREE (vr_value[i]->equiv); + free (vr_value[i]); + } + + free (vr_value); + free (vr_phi_edge_counts); + + /* So that we can distinguish between VRP data being available + and not available. */ + vr_value = NULL; + vr_phi_edge_counts = NULL; +} + + +/* Main entry point to VRP (Value Range Propagation). This pass is + loosely based on J. R. C. Patterson, ``Accurate Static Branch + Prediction by Value Range Propagation,'' in SIGPLAN Conference on + Programming Language Design and Implementation, pp. 67-78, 1995. + Also available at http://citeseer.ist.psu.edu/patterson95accurate.html + + This is essentially an SSA-CCP pass modified to deal with ranges + instead of constants. + + While propagating ranges, we may find that two or more SSA name + have equivalent, though distinct ranges. For instance, + + 1 x_9 = p_3->a; + 2 p_4 = ASSERT_EXPR <p_3, p_3 != 0> + 3 if (p_4 == q_2) + 4 p_5 = ASSERT_EXPR <p_4, p_4 == q_2>; + 5 endif + 6 if (q_2) + + In the code above, pointer p_5 has range [q_2, q_2], but from the + code we can also determine that p_5 cannot be NULL and, if q_2 had + a non-varying range, p_5's range should also be compatible with it. + + These equivalences are created by two expressions: ASSERT_EXPR and + copy operations. Since p_5 is an assertion on p_4, and p_4 was the + result of another assertion, then we can use the fact that p_5 and + p_4 are equivalent when evaluating p_5's range. + + Together with value ranges, we also propagate these equivalences + between names so that we can take advantage of information from + multiple ranges when doing final replacement. Note that this + equivalency relation is transitive but not symmetric. + + In the example above, p_5 is equivalent to p_4, q_2 and p_3, but we + cannot assert that q_2 is equivalent to p_5 because q_2 may be used + in contexts where that assertion does not hold (e.g., in line 6). + + TODO, the main difference between this pass and Patterson's is that + we do not propagate edge probabilities. We only compute whether + edges can be taken or not. That is, instead of having a spectrum + of jump probabilities between 0 and 1, we only deal with 0, 1 and + DON'T KNOW. In the future, it may be worthwhile to propagate + probabilities to aid branch prediction. */ + +static unsigned int +execute_vrp (void) +{ + int i; + edge e; + switch_update *su; + + loop_optimizer_init (LOOPS_NORMAL | LOOPS_HAVE_RECORDED_EXITS); + rewrite_into_loop_closed_ssa (NULL, TODO_update_ssa); + scev_initialize (); + + /* ??? This ends up using stale EDGE_DFS_BACK for liveness computation. + Inserting assertions may split edges which will invalidate + EDGE_DFS_BACK. */ + insert_range_assertions (); + + to_remove_edges.create (10); + to_update_switch_stmts.create (5); + threadedge_initialize_values (); + + /* For visiting PHI nodes we need EDGE_DFS_BACK computed. */ + mark_dfs_back_edges (); + + vrp_initialize (); + ssa_propagate (vrp_visit_stmt, vrp_visit_phi_node); + vrp_finalize (); + + free_numbers_of_iterations_estimates (); + + /* ASSERT_EXPRs must be removed before finalizing jump threads + as finalizing jump threads calls the CFG cleanup code which + does not properly handle ASSERT_EXPRs. */ + remove_range_assertions (); + + /* If we exposed any new variables, go ahead and put them into + SSA form now, before we handle jump threading. This simplifies + interactions between rewriting of _DECL nodes into SSA form + and rewriting SSA_NAME nodes into SSA form after block + duplication and CFG manipulation. */ + update_ssa (TODO_update_ssa); + + finalize_jump_threads (); + + /* Remove dead edges from SWITCH_EXPR optimization. This leaves the + CFG in a broken state and requires a cfg_cleanup run. */ + FOR_EACH_VEC_ELT (to_remove_edges, i, e) + remove_edge (e); + /* Update SWITCH_EXPR case label vector. */ + FOR_EACH_VEC_ELT (to_update_switch_stmts, i, su) + { + size_t j; + size_t n = TREE_VEC_LENGTH (su->vec); + tree label; + gimple_switch_set_num_labels (su->stmt, n); + for (j = 0; j < n; j++) + gimple_switch_set_label (su->stmt, j, TREE_VEC_ELT (su->vec, j)); + /* As we may have replaced the default label with a regular one + make sure to make it a real default label again. This ensures + optimal expansion. */ + label = gimple_switch_label (su->stmt, 0); + CASE_LOW (label) = NULL_TREE; + CASE_HIGH (label) = NULL_TREE; + } + + if (to_remove_edges.length () > 0) + { + free_dominance_info (CDI_DOMINATORS); + if (current_loops) + loops_state_set (LOOPS_NEED_FIXUP); + } + + to_remove_edges.release (); + to_update_switch_stmts.release (); + threadedge_finalize_values (); + + scev_finalize (); + loop_optimizer_finalize (); + return 0; +} + +static bool +gate_vrp (void) +{ + return flag_tree_vrp != 0; +} + +namespace { + +const pass_data pass_data_vrp = +{ + GIMPLE_PASS, /* type */ + "vrp", /* name */ + OPTGROUP_NONE, /* optinfo_flags */ + true, /* has_gate */ + true, /* has_execute */ + TV_TREE_VRP, /* tv_id */ + PROP_ssa, /* properties_required */ + 0, /* properties_provided */ + 0, /* properties_destroyed */ + 0, /* todo_flags_start */ + ( TODO_cleanup_cfg | TODO_update_ssa + | TODO_verify_ssa + | TODO_verify_flow ), /* todo_flags_finish */ +}; + +class pass_vrp : public gimple_opt_pass +{ +public: + pass_vrp (gcc::context *ctxt) + : gimple_opt_pass (pass_data_vrp, ctxt) + {} + + /* opt_pass methods: */ + opt_pass * clone () { return new pass_vrp (m_ctxt); } + bool gate () { return gate_vrp (); } + unsigned int execute () { return execute_vrp (); } + +}; // class pass_vrp + +} // anon namespace + +gimple_opt_pass * +make_pass_vrp (gcc::context *ctxt) +{ + return new pass_vrp (ctxt); +} |