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Diffstat (limited to 'gcc-4.8.1/gcc/gimple-fold.c')
| -rw-r--r-- | gcc-4.8.1/gcc/gimple-fold.c | 3283 |
1 files changed, 0 insertions, 3283 deletions
diff --git a/gcc-4.8.1/gcc/gimple-fold.c b/gcc-4.8.1/gcc/gimple-fold.c deleted file mode 100644 index b9211a9ad..000000000 --- a/gcc-4.8.1/gcc/gimple-fold.c +++ /dev/null @@ -1,3283 +0,0 @@ -/* Statement simplification on GIMPLE. - Copyright (C) 2010-2013 Free Software Foundation, Inc. - Split out from tree-ssa-ccp.c. - -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 "tree.h" -#include "flags.h" -#include "function.h" -#include "dumpfile.h" -#include "tree-flow.h" -#include "tree-ssa-propagate.h" -#include "target.h" -#include "gimple-fold.h" - -/* Return true when DECL can be referenced from current unit. - FROM_DECL (if non-null) specify constructor of variable DECL was taken from. - We can get declarations that are not possible to reference for various - reasons: - - 1) When analyzing C++ virtual tables. - C++ virtual tables do have known constructors even - when they are keyed to other compilation unit. - Those tables can contain pointers to methods and vars - in other units. Those methods have both STATIC and EXTERNAL - set. - 2) In WHOPR mode devirtualization might lead to reference - to method that was partitioned elsehwere. - In this case we have static VAR_DECL or FUNCTION_DECL - that has no corresponding callgraph/varpool node - declaring the body. - 3) COMDAT functions referred by external vtables that - we devirtualize only during final copmilation stage. - At this time we already decided that we will not output - the function body and thus we can't reference the symbol - directly. */ - -static bool -can_refer_decl_in_current_unit_p (tree decl, tree from_decl) -{ - struct varpool_node *vnode; - struct cgraph_node *node; - symtab_node snode; - - /* We will later output the initializer, so we can refer to it. - So we are concerned only when DECL comes from initializer of - external var. */ - if (!from_decl - || TREE_CODE (from_decl) != VAR_DECL - || !DECL_EXTERNAL (from_decl) - || (flag_ltrans - && symtab_get_node (from_decl)->symbol.in_other_partition)) - return true; - /* We are concerned only about static/external vars and functions. */ - if ((!TREE_STATIC (decl) && !DECL_EXTERNAL (decl)) - || (TREE_CODE (decl) != VAR_DECL && TREE_CODE (decl) != FUNCTION_DECL)) - return true; - /* Weakrefs have somewhat confusing DECL_EXTERNAL flag set; they - are always safe. */ - if (DECL_EXTERNAL (decl) - && lookup_attribute ("weakref", DECL_ATTRIBUTES (decl))) - return true; - /* We are folding reference from external vtable. The vtable may reffer - to a symbol keyed to other compilation unit. The other compilation - unit may be in separate DSO and the symbol may be hidden. */ - if (DECL_VISIBILITY_SPECIFIED (decl) - && DECL_EXTERNAL (decl) - && (!(snode = symtab_get_node (decl)) || !snode->symbol.in_other_partition)) - return false; - /* When function is public, we always can introduce new reference. - Exception are the COMDAT functions where introducing a direct - reference imply need to include function body in the curren tunit. */ - if (TREE_PUBLIC (decl) && !DECL_COMDAT (decl)) - return true; - /* We are not at ltrans stage; so don't worry about WHOPR. - Also when still gimplifying all referred comdat functions will be - produced. - - As observed in PR20991 for already optimized out comdat virtual functions - it may be tempting to not necessarily give up because the copy will be - output elsewhere when corresponding vtable is output. - This is however not possible - ABI specify that COMDATs are output in - units where they are used and when the other unit was compiled with LTO - it is possible that vtable was kept public while the function itself - was privatized. */ - if (!flag_ltrans && (!DECL_COMDAT (decl) || !cgraph_function_flags_ready)) - return true; - - /* OK we are seeing either COMDAT or static variable. In this case we must - check that the definition is still around so we can refer it. */ - if (TREE_CODE (decl) == FUNCTION_DECL) - { - node = cgraph_get_node (decl); - /* Check that we still have function body and that we didn't took - the decision to eliminate offline copy of the function yet. - The second is important when devirtualization happens during final - compilation stage when making a new reference no longer makes callee - to be compiled. */ - if (!node || !node->analyzed || node->global.inlined_to) - { - gcc_checking_assert (!TREE_ASM_WRITTEN (decl)); - return false; - } - } - else if (TREE_CODE (decl) == VAR_DECL) - { - vnode = varpool_get_node (decl); - if (!vnode || !vnode->analyzed) - { - gcc_checking_assert (!TREE_ASM_WRITTEN (decl)); - return false; - } - } - return true; -} - -/* CVAL is value taken from DECL_INITIAL of variable. Try to transform it into - acceptable form for is_gimple_min_invariant. - FROM_DECL (if non-NULL) specify variable whose constructor contains CVAL. */ - -tree -canonicalize_constructor_val (tree cval, tree from_decl) -{ - tree orig_cval = cval; - STRIP_NOPS (cval); - if (TREE_CODE (cval) == POINTER_PLUS_EXPR - && TREE_CODE (TREE_OPERAND (cval, 1)) == INTEGER_CST) - { - tree ptr = TREE_OPERAND (cval, 0); - if (is_gimple_min_invariant (ptr)) - cval = build1_loc (EXPR_LOCATION (cval), - ADDR_EXPR, TREE_TYPE (ptr), - fold_build2 (MEM_REF, TREE_TYPE (TREE_TYPE (ptr)), - ptr, - fold_convert (ptr_type_node, - TREE_OPERAND (cval, 1)))); - } - if (TREE_CODE (cval) == ADDR_EXPR) - { - tree base = NULL_TREE; - if (TREE_CODE (TREE_OPERAND (cval, 0)) == COMPOUND_LITERAL_EXPR) - { - base = COMPOUND_LITERAL_EXPR_DECL (TREE_OPERAND (cval, 0)); - if (base) - TREE_OPERAND (cval, 0) = base; - } - else - base = get_base_address (TREE_OPERAND (cval, 0)); - if (!base) - return NULL_TREE; - - if ((TREE_CODE (base) == VAR_DECL - || TREE_CODE (base) == FUNCTION_DECL) - && !can_refer_decl_in_current_unit_p (base, from_decl)) - return NULL_TREE; - if (TREE_CODE (base) == VAR_DECL) - TREE_ADDRESSABLE (base) = 1; - else if (TREE_CODE (base) == FUNCTION_DECL) - { - /* Make sure we create a cgraph node for functions we'll reference. - They can be non-existent if the reference comes from an entry - of an external vtable for example. */ - cgraph_get_create_node (base); - } - /* Fixup types in global initializers. */ - if (TREE_TYPE (TREE_TYPE (cval)) != TREE_TYPE (TREE_OPERAND (cval, 0))) - cval = build_fold_addr_expr (TREE_OPERAND (cval, 0)); - - if (!useless_type_conversion_p (TREE_TYPE (orig_cval), TREE_TYPE (cval))) - cval = fold_convert (TREE_TYPE (orig_cval), cval); - return cval; - } - return orig_cval; -} - -/* If SYM is a constant variable with known value, return the value. - NULL_TREE is returned otherwise. */ - -tree -get_symbol_constant_value (tree sym) -{ - if (const_value_known_p (sym)) - { - tree val = DECL_INITIAL (sym); - if (val) - { - val = canonicalize_constructor_val (unshare_expr (val), sym); - if (val && is_gimple_min_invariant (val)) - return val; - else - return NULL_TREE; - } - /* Variables declared 'const' without an initializer - have zero as the initializer if they may not be - overridden at link or run time. */ - if (!val - && (INTEGRAL_TYPE_P (TREE_TYPE (sym)) - || SCALAR_FLOAT_TYPE_P (TREE_TYPE (sym)))) - return build_zero_cst (TREE_TYPE (sym)); - } - - return NULL_TREE; -} - - - -/* Subroutine of fold_stmt. We perform several simplifications of the - memory reference tree EXPR and make sure to re-gimplify them properly - after propagation of constant addresses. IS_LHS is true if the - reference is supposed to be an lvalue. */ - -static tree -maybe_fold_reference (tree expr, bool is_lhs) -{ - tree *t = &expr; - tree result; - - if ((TREE_CODE (expr) == VIEW_CONVERT_EXPR - || TREE_CODE (expr) == REALPART_EXPR - || TREE_CODE (expr) == IMAGPART_EXPR) - && CONSTANT_CLASS_P (TREE_OPERAND (expr, 0))) - return fold_unary_loc (EXPR_LOCATION (expr), - TREE_CODE (expr), - TREE_TYPE (expr), - TREE_OPERAND (expr, 0)); - else if (TREE_CODE (expr) == BIT_FIELD_REF - && CONSTANT_CLASS_P (TREE_OPERAND (expr, 0))) - return fold_ternary_loc (EXPR_LOCATION (expr), - TREE_CODE (expr), - TREE_TYPE (expr), - TREE_OPERAND (expr, 0), - TREE_OPERAND (expr, 1), - TREE_OPERAND (expr, 2)); - - while (handled_component_p (*t)) - t = &TREE_OPERAND (*t, 0); - - /* Canonicalize MEM_REFs invariant address operand. Do this first - to avoid feeding non-canonical MEM_REFs elsewhere. */ - if (TREE_CODE (*t) == MEM_REF - && !is_gimple_mem_ref_addr (TREE_OPERAND (*t, 0))) - { - bool volatile_p = TREE_THIS_VOLATILE (*t); - tree tem = fold_binary (MEM_REF, TREE_TYPE (*t), - TREE_OPERAND (*t, 0), - TREE_OPERAND (*t, 1)); - if (tem) - { - TREE_THIS_VOLATILE (tem) = volatile_p; - *t = tem; - tem = maybe_fold_reference (expr, is_lhs); - if (tem) - return tem; - return expr; - } - } - - if (!is_lhs - && (result = fold_const_aggregate_ref (expr)) - && is_gimple_min_invariant (result)) - return result; - - /* Fold back MEM_REFs to reference trees. */ - if (TREE_CODE (*t) == MEM_REF - && TREE_CODE (TREE_OPERAND (*t, 0)) == ADDR_EXPR - && integer_zerop (TREE_OPERAND (*t, 1)) - && (TREE_THIS_VOLATILE (*t) - == TREE_THIS_VOLATILE (TREE_OPERAND (TREE_OPERAND (*t, 0), 0))) - && !TYPE_REF_CAN_ALIAS_ALL (TREE_TYPE (TREE_OPERAND (*t, 1))) - && (TYPE_MAIN_VARIANT (TREE_TYPE (*t)) - == TYPE_MAIN_VARIANT (TREE_TYPE (TREE_TYPE (TREE_OPERAND (*t, 1))))) - /* We have to look out here to not drop a required conversion - from the rhs to the lhs if is_lhs, but we don't have the - rhs here to verify that. Thus require strict type - compatibility. */ - && types_compatible_p (TREE_TYPE (*t), - TREE_TYPE (TREE_OPERAND - (TREE_OPERAND (*t, 0), 0)))) - { - tree tem; - *t = TREE_OPERAND (TREE_OPERAND (*t, 0), 0); - tem = maybe_fold_reference (expr, is_lhs); - if (tem) - return tem; - return expr; - } - else if (TREE_CODE (*t) == TARGET_MEM_REF) - { - tree tem = maybe_fold_tmr (*t); - if (tem) - { - *t = tem; - tem = maybe_fold_reference (expr, is_lhs); - if (tem) - return tem; - return expr; - } - } - - return NULL_TREE; -} - - -/* Attempt to fold an assignment statement pointed-to by SI. Returns a - replacement rhs for the statement or NULL_TREE if no simplification - could be made. It is assumed that the operands have been previously - folded. */ - -static tree -fold_gimple_assign (gimple_stmt_iterator *si) -{ - gimple stmt = gsi_stmt (*si); - enum tree_code subcode = gimple_assign_rhs_code (stmt); - location_t loc = gimple_location (stmt); - - tree result = NULL_TREE; - - switch (get_gimple_rhs_class (subcode)) - { - case GIMPLE_SINGLE_RHS: - { - tree rhs = gimple_assign_rhs1 (stmt); - - if (REFERENCE_CLASS_P (rhs)) - return maybe_fold_reference (rhs, false); - - else if (TREE_CODE (rhs) == ADDR_EXPR) - { - tree ref = TREE_OPERAND (rhs, 0); - tree tem = maybe_fold_reference (ref, true); - if (tem - && TREE_CODE (tem) == MEM_REF - && integer_zerop (TREE_OPERAND (tem, 1))) - result = fold_convert (TREE_TYPE (rhs), TREE_OPERAND (tem, 0)); - else if (tem) - result = fold_convert (TREE_TYPE (rhs), - build_fold_addr_expr_loc (loc, tem)); - else if (TREE_CODE (ref) == MEM_REF - && integer_zerop (TREE_OPERAND (ref, 1))) - result = fold_convert (TREE_TYPE (rhs), TREE_OPERAND (ref, 0)); - } - - else if (TREE_CODE (rhs) == CONSTRUCTOR - && TREE_CODE (TREE_TYPE (rhs)) == VECTOR_TYPE - && (CONSTRUCTOR_NELTS (rhs) - == TYPE_VECTOR_SUBPARTS (TREE_TYPE (rhs)))) - { - /* Fold a constant vector CONSTRUCTOR to VECTOR_CST. */ - unsigned i; - tree val; - - FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (rhs), i, val) - if (TREE_CODE (val) != INTEGER_CST - && TREE_CODE (val) != REAL_CST - && TREE_CODE (val) != FIXED_CST) - return NULL_TREE; - - return build_vector_from_ctor (TREE_TYPE (rhs), - CONSTRUCTOR_ELTS (rhs)); - } - - else if (DECL_P (rhs)) - return get_symbol_constant_value (rhs); - - /* If we couldn't fold the RHS, hand over to the generic - fold routines. */ - if (result == NULL_TREE) - result = fold (rhs); - - /* Strip away useless type conversions. Both the NON_LVALUE_EXPR - that may have been added by fold, and "useless" type - conversions that might now be apparent due to propagation. */ - STRIP_USELESS_TYPE_CONVERSION (result); - - if (result != rhs && valid_gimple_rhs_p (result)) - return result; - - return NULL_TREE; - } - break; - - case GIMPLE_UNARY_RHS: - { - tree rhs = gimple_assign_rhs1 (stmt); - - result = fold_unary_loc (loc, subcode, gimple_expr_type (stmt), rhs); - if (result) - { - /* If the operation was a conversion do _not_ mark a - resulting constant with TREE_OVERFLOW if the original - constant was not. These conversions have implementation - defined behavior and retaining the TREE_OVERFLOW flag - here would confuse later passes such as VRP. */ - if (CONVERT_EXPR_CODE_P (subcode) - && TREE_CODE (result) == INTEGER_CST - && TREE_CODE (rhs) == INTEGER_CST) - TREE_OVERFLOW (result) = TREE_OVERFLOW (rhs); - - STRIP_USELESS_TYPE_CONVERSION (result); - if (valid_gimple_rhs_p (result)) - return result; - } - } - break; - - case GIMPLE_BINARY_RHS: - /* Try to canonicalize for boolean-typed X the comparisons - X == 0, X == 1, X != 0, and X != 1. */ - if (gimple_assign_rhs_code (stmt) == EQ_EXPR - || gimple_assign_rhs_code (stmt) == NE_EXPR) - { - tree lhs = gimple_assign_lhs (stmt); - tree op1 = gimple_assign_rhs1 (stmt); - tree op2 = gimple_assign_rhs2 (stmt); - tree type = TREE_TYPE (op1); - - /* Check whether the comparison operands are of the same boolean - type as the result type is. - Check that second operand is an integer-constant with value - one or zero. */ - if (TREE_CODE (op2) == INTEGER_CST - && (integer_zerop (op2) || integer_onep (op2)) - && useless_type_conversion_p (TREE_TYPE (lhs), type)) - { - enum tree_code cmp_code = gimple_assign_rhs_code (stmt); - bool is_logical_not = false; - - /* X == 0 and X != 1 is a logical-not.of X - X == 1 and X != 0 is X */ - if ((cmp_code == EQ_EXPR && integer_zerop (op2)) - || (cmp_code == NE_EXPR && integer_onep (op2))) - is_logical_not = true; - - if (is_logical_not == false) - result = op1; - /* Only for one-bit precision typed X the transformation - !X -> ~X is valied. */ - else if (TYPE_PRECISION (type) == 1) - result = build1_loc (gimple_location (stmt), BIT_NOT_EXPR, - type, op1); - /* Otherwise we use !X -> X ^ 1. */ - else - result = build2_loc (gimple_location (stmt), BIT_XOR_EXPR, - type, op1, build_int_cst (type, 1)); - - } - } - - if (!result) - result = fold_binary_loc (loc, subcode, - TREE_TYPE (gimple_assign_lhs (stmt)), - gimple_assign_rhs1 (stmt), - gimple_assign_rhs2 (stmt)); - - if (result) - { - STRIP_USELESS_TYPE_CONVERSION (result); - if (valid_gimple_rhs_p (result)) - return result; - } - break; - - case GIMPLE_TERNARY_RHS: - /* Try to fold a conditional expression. */ - if (gimple_assign_rhs_code (stmt) == COND_EXPR) - { - tree op0 = gimple_assign_rhs1 (stmt); - tree tem; - bool set = false; - location_t cond_loc = gimple_location (stmt); - - if (COMPARISON_CLASS_P (op0)) - { - fold_defer_overflow_warnings (); - tem = fold_binary_loc (cond_loc, - TREE_CODE (op0), TREE_TYPE (op0), - TREE_OPERAND (op0, 0), - TREE_OPERAND (op0, 1)); - /* This is actually a conditional expression, not a GIMPLE - conditional statement, however, the valid_gimple_rhs_p - test still applies. */ - set = (tem && is_gimple_condexpr (tem) - && valid_gimple_rhs_p (tem)); - fold_undefer_overflow_warnings (set, stmt, 0); - } - else if (is_gimple_min_invariant (op0)) - { - tem = op0; - set = true; - } - else - return NULL_TREE; - - if (set) - result = fold_build3_loc (cond_loc, COND_EXPR, - TREE_TYPE (gimple_assign_lhs (stmt)), tem, - gimple_assign_rhs2 (stmt), - gimple_assign_rhs3 (stmt)); - } - - if (!result) - result = fold_ternary_loc (loc, subcode, - TREE_TYPE (gimple_assign_lhs (stmt)), - gimple_assign_rhs1 (stmt), - gimple_assign_rhs2 (stmt), - gimple_assign_rhs3 (stmt)); - - if (result) - { - STRIP_USELESS_TYPE_CONVERSION (result); - if (valid_gimple_rhs_p (result)) - return result; - } - break; - - case GIMPLE_INVALID_RHS: - gcc_unreachable (); - } - - return NULL_TREE; -} - -/* Attempt to fold a conditional statement. Return true if any changes were - made. We only attempt to fold the condition expression, and do not perform - any transformation that would require alteration of the cfg. It is - assumed that the operands have been previously folded. */ - -static bool -fold_gimple_cond (gimple stmt) -{ - tree result = fold_binary_loc (gimple_location (stmt), - gimple_cond_code (stmt), - boolean_type_node, - gimple_cond_lhs (stmt), - gimple_cond_rhs (stmt)); - - if (result) - { - STRIP_USELESS_TYPE_CONVERSION (result); - if (is_gimple_condexpr (result) && valid_gimple_rhs_p (result)) - { - gimple_cond_set_condition_from_tree (stmt, result); - return true; - } - } - - return false; -} - -/* Convert EXPR into a GIMPLE value suitable for substitution on the - RHS of an assignment. Insert the necessary statements before - iterator *SI_P. The statement at *SI_P, which must be a GIMPLE_CALL - is replaced. If the call is expected to produces a result, then it - is replaced by an assignment of the new RHS to the result variable. - If the result is to be ignored, then the call is replaced by a - GIMPLE_NOP. A proper VDEF chain is retained by making the first - VUSE and the last VDEF of the whole sequence be the same as the replaced - statement and using new SSA names for stores in between. */ - -void -gimplify_and_update_call_from_tree (gimple_stmt_iterator *si_p, tree expr) -{ - tree lhs; - gimple stmt, new_stmt; - gimple_stmt_iterator i; - gimple_seq stmts = NULL; - struct gimplify_ctx gctx; - gimple laststore; - tree reaching_vuse; - - stmt = gsi_stmt (*si_p); - - gcc_assert (is_gimple_call (stmt)); - - push_gimplify_context (&gctx); - gctx.into_ssa = gimple_in_ssa_p (cfun); - - lhs = gimple_call_lhs (stmt); - if (lhs == NULL_TREE) - { - gimplify_and_add (expr, &stmts); - /* We can end up with folding a memcpy of an empty class assignment - which gets optimized away by C++ gimplification. */ - if (gimple_seq_empty_p (stmts)) - { - pop_gimplify_context (NULL); - if (gimple_in_ssa_p (cfun)) - { - unlink_stmt_vdef (stmt); - release_defs (stmt); - } - gsi_replace (si_p, gimple_build_nop (), true); - return; - } - } - else - { - tree tmp = get_initialized_tmp_var (expr, &stmts, NULL); - new_stmt = gimple_build_assign (lhs, tmp); - i = gsi_last (stmts); - gsi_insert_after_without_update (&i, new_stmt, - GSI_CONTINUE_LINKING); - } - - pop_gimplify_context (NULL); - - if (gimple_has_location (stmt)) - annotate_all_with_location (stmts, gimple_location (stmt)); - - /* First iterate over the replacement statements backward, assigning - virtual operands to their defining statements. */ - laststore = NULL; - for (i = gsi_last (stmts); !gsi_end_p (i); gsi_prev (&i)) - { - new_stmt = gsi_stmt (i); - if ((gimple_assign_single_p (new_stmt) - && !is_gimple_reg (gimple_assign_lhs (new_stmt))) - || (is_gimple_call (new_stmt) - && (gimple_call_flags (new_stmt) - & (ECF_NOVOPS | ECF_PURE | ECF_CONST | ECF_NORETURN)) == 0)) - { - tree vdef; - if (!laststore) - vdef = gimple_vdef (stmt); - else - vdef = make_ssa_name (gimple_vop (cfun), new_stmt); - gimple_set_vdef (new_stmt, vdef); - if (vdef && TREE_CODE (vdef) == SSA_NAME) - SSA_NAME_DEF_STMT (vdef) = new_stmt; - laststore = new_stmt; - } - } - - /* Second iterate over the statements forward, assigning virtual - operands to their uses. */ - reaching_vuse = gimple_vuse (stmt); - for (i = gsi_start (stmts); !gsi_end_p (i); gsi_next (&i)) - { - new_stmt = gsi_stmt (i); - /* If the new statement possibly has a VUSE, update it with exact SSA - name we know will reach this one. */ - if (gimple_has_mem_ops (new_stmt)) - gimple_set_vuse (new_stmt, reaching_vuse); - gimple_set_modified (new_stmt, true); - if (gimple_vdef (new_stmt)) - reaching_vuse = gimple_vdef (new_stmt); - } - - /* If the new sequence does not do a store release the virtual - definition of the original statement. */ - if (reaching_vuse - && reaching_vuse == gimple_vuse (stmt)) - { - tree vdef = gimple_vdef (stmt); - if (vdef - && TREE_CODE (vdef) == SSA_NAME) - { - unlink_stmt_vdef (stmt); - release_ssa_name (vdef); - } - } - - /* Finally replace the original statement with the sequence. */ - gsi_replace_with_seq (si_p, stmts, false); -} - -/* Return the string length, maximum string length or maximum value of - ARG in LENGTH. - If ARG is an SSA name variable, follow its use-def chains. If LENGTH - is not NULL and, for TYPE == 0, its value is not equal to the length - we determine or if we are unable to determine the length or value, - return false. VISITED is a bitmap of visited variables. - TYPE is 0 if string length should be returned, 1 for maximum string - length and 2 for maximum value ARG can have. */ - -static bool -get_maxval_strlen (tree arg, tree *length, bitmap visited, int type) -{ - tree var, val; - gimple def_stmt; - - if (TREE_CODE (arg) != SSA_NAME) - { - /* We can end up with &(*iftmp_1)[0] here as well, so handle it. */ - if (TREE_CODE (arg) == ADDR_EXPR - && TREE_CODE (TREE_OPERAND (arg, 0)) == ARRAY_REF - && integer_zerop (TREE_OPERAND (TREE_OPERAND (arg, 0), 1))) - { - tree aop0 = TREE_OPERAND (TREE_OPERAND (arg, 0), 0); - if (TREE_CODE (aop0) == INDIRECT_REF - && TREE_CODE (TREE_OPERAND (aop0, 0)) == SSA_NAME) - return get_maxval_strlen (TREE_OPERAND (aop0, 0), - length, visited, type); - } - - if (type == 2) - { - val = arg; - if (TREE_CODE (val) != INTEGER_CST - || tree_int_cst_sgn (val) < 0) - return false; - } - else - val = c_strlen (arg, 1); - if (!val) - return false; - - if (*length) - { - if (type > 0) - { - if (TREE_CODE (*length) != INTEGER_CST - || TREE_CODE (val) != INTEGER_CST) - return false; - - if (tree_int_cst_lt (*length, val)) - *length = val; - return true; - } - else if (simple_cst_equal (val, *length) != 1) - return false; - } - - *length = val; - return true; - } - - /* If ARG is registered for SSA update we cannot look at its defining - statement. */ - if (name_registered_for_update_p (arg)) - return false; - - /* If we were already here, break the infinite cycle. */ - if (!bitmap_set_bit (visited, SSA_NAME_VERSION (arg))) - return true; - - var = arg; - def_stmt = SSA_NAME_DEF_STMT (var); - - switch (gimple_code (def_stmt)) - { - case GIMPLE_ASSIGN: - /* The RHS of the statement defining VAR must either have a - constant length or come from another SSA_NAME with a constant - length. */ - if (gimple_assign_single_p (def_stmt) - || gimple_assign_unary_nop_p (def_stmt)) - { - tree rhs = gimple_assign_rhs1 (def_stmt); - return get_maxval_strlen (rhs, length, visited, type); - } - else if (gimple_assign_rhs_code (def_stmt) == COND_EXPR) - { - tree op2 = gimple_assign_rhs2 (def_stmt); - tree op3 = gimple_assign_rhs3 (def_stmt); - return get_maxval_strlen (op2, length, visited, type) - && get_maxval_strlen (op3, length, visited, type); - } - return false; - - case GIMPLE_PHI: - { - /* All the arguments of the PHI node must have the same constant - length. */ - unsigned i; - - for (i = 0; i < gimple_phi_num_args (def_stmt); i++) - { - tree arg = gimple_phi_arg (def_stmt, i)->def; - - /* If this PHI has itself as an argument, we cannot - determine the string length of this argument. However, - if we can find a constant string length for the other - PHI args then we can still be sure that this is a - constant string length. So be optimistic and just - continue with the next argument. */ - if (arg == gimple_phi_result (def_stmt)) - continue; - - if (!get_maxval_strlen (arg, length, visited, type)) - return false; - } - } - return true; - - default: - return false; - } -} - - -/* Fold builtin call in statement STMT. Returns a simplified tree. - We may return a non-constant expression, including another call - to a different function and with different arguments, e.g., - substituting memcpy for strcpy when the string length is known. - Note that some builtins expand into inline code that may not - be valid in GIMPLE. Callers must take care. */ - -tree -gimple_fold_builtin (gimple stmt) -{ - tree result, val[3]; - tree callee, a; - int arg_idx, type; - bitmap visited; - bool ignore; - int nargs; - location_t loc = gimple_location (stmt); - - gcc_assert (is_gimple_call (stmt)); - - ignore = (gimple_call_lhs (stmt) == NULL); - - /* First try the generic builtin folder. If that succeeds, return the - result directly. */ - result = fold_call_stmt (stmt, ignore); - if (result) - { - if (ignore) - STRIP_NOPS (result); - return result; - } - - /* Ignore MD builtins. */ - callee = gimple_call_fndecl (stmt); - if (DECL_BUILT_IN_CLASS (callee) == BUILT_IN_MD) - return NULL_TREE; - - /* Give up for always_inline inline builtins until they are - inlined. */ - if (avoid_folding_inline_builtin (callee)) - return NULL_TREE; - - /* If the builtin could not be folded, and it has no argument list, - we're done. */ - nargs = gimple_call_num_args (stmt); - if (nargs == 0) - return NULL_TREE; - - /* Limit the work only for builtins we know how to simplify. */ - switch (DECL_FUNCTION_CODE (callee)) - { - case BUILT_IN_STRLEN: - case BUILT_IN_FPUTS: - case BUILT_IN_FPUTS_UNLOCKED: - arg_idx = 0; - type = 0; - break; - case BUILT_IN_STRCPY: - case BUILT_IN_STRNCPY: - arg_idx = 1; - type = 0; - break; - case BUILT_IN_MEMCPY_CHK: - case BUILT_IN_MEMPCPY_CHK: - case BUILT_IN_MEMMOVE_CHK: - case BUILT_IN_MEMSET_CHK: - case BUILT_IN_STRNCPY_CHK: - case BUILT_IN_STPNCPY_CHK: - arg_idx = 2; - type = 2; - break; - case BUILT_IN_STRCPY_CHK: - case BUILT_IN_STPCPY_CHK: - arg_idx = 1; - type = 1; - break; - case BUILT_IN_SNPRINTF_CHK: - case BUILT_IN_VSNPRINTF_CHK: - arg_idx = 1; - type = 2; - break; - default: - return NULL_TREE; - } - - if (arg_idx >= nargs) - return NULL_TREE; - - /* Try to use the dataflow information gathered by the CCP process. */ - visited = BITMAP_ALLOC (NULL); - bitmap_clear (visited); - - memset (val, 0, sizeof (val)); - a = gimple_call_arg (stmt, arg_idx); - if (!get_maxval_strlen (a, &val[arg_idx], visited, type)) - val[arg_idx] = NULL_TREE; - - BITMAP_FREE (visited); - - result = NULL_TREE; - switch (DECL_FUNCTION_CODE (callee)) - { - case BUILT_IN_STRLEN: - if (val[0] && nargs == 1) - { - tree new_val = - fold_convert (TREE_TYPE (gimple_call_lhs (stmt)), val[0]); - - /* If the result is not a valid gimple value, or not a cast - of a valid gimple value, then we cannot use the result. */ - if (is_gimple_val (new_val) - || (CONVERT_EXPR_P (new_val) - && is_gimple_val (TREE_OPERAND (new_val, 0)))) - return new_val; - } - break; - - case BUILT_IN_STRCPY: - if (val[1] && is_gimple_val (val[1]) && nargs == 2) - result = fold_builtin_strcpy (loc, callee, - gimple_call_arg (stmt, 0), - gimple_call_arg (stmt, 1), - val[1]); - break; - - case BUILT_IN_STRNCPY: - if (val[1] && is_gimple_val (val[1]) && nargs == 3) - result = fold_builtin_strncpy (loc, callee, - gimple_call_arg (stmt, 0), - gimple_call_arg (stmt, 1), - gimple_call_arg (stmt, 2), - val[1]); - break; - - case BUILT_IN_FPUTS: - if (nargs == 2) - result = fold_builtin_fputs (loc, gimple_call_arg (stmt, 0), - gimple_call_arg (stmt, 1), - ignore, false, val[0]); - break; - - case BUILT_IN_FPUTS_UNLOCKED: - if (nargs == 2) - result = fold_builtin_fputs (loc, gimple_call_arg (stmt, 0), - gimple_call_arg (stmt, 1), - ignore, true, val[0]); - break; - - case BUILT_IN_MEMCPY_CHK: - case BUILT_IN_MEMPCPY_CHK: - case BUILT_IN_MEMMOVE_CHK: - case BUILT_IN_MEMSET_CHK: - if (val[2] && is_gimple_val (val[2]) && nargs == 4) - result = fold_builtin_memory_chk (loc, callee, - gimple_call_arg (stmt, 0), - gimple_call_arg (stmt, 1), - gimple_call_arg (stmt, 2), - gimple_call_arg (stmt, 3), - val[2], ignore, - DECL_FUNCTION_CODE (callee)); - break; - - case BUILT_IN_STRCPY_CHK: - case BUILT_IN_STPCPY_CHK: - if (val[1] && is_gimple_val (val[1]) && nargs == 3) - result = fold_builtin_stxcpy_chk (loc, callee, - gimple_call_arg (stmt, 0), - gimple_call_arg (stmt, 1), - gimple_call_arg (stmt, 2), - val[1], ignore, - DECL_FUNCTION_CODE (callee)); - break; - - case BUILT_IN_STRNCPY_CHK: - case BUILT_IN_STPNCPY_CHK: - if (val[2] && is_gimple_val (val[2]) && nargs == 4) - result = fold_builtin_stxncpy_chk (loc, gimple_call_arg (stmt, 0), - gimple_call_arg (stmt, 1), - gimple_call_arg (stmt, 2), - gimple_call_arg (stmt, 3), - val[2], ignore, - DECL_FUNCTION_CODE (callee)); - break; - - case BUILT_IN_SNPRINTF_CHK: - case BUILT_IN_VSNPRINTF_CHK: - if (val[1] && is_gimple_val (val[1])) - result = gimple_fold_builtin_snprintf_chk (stmt, val[1], - DECL_FUNCTION_CODE (callee)); - break; - - default: - gcc_unreachable (); - } - - if (result && ignore) - result = fold_ignored_result (result); - return result; -} - - -/* Return a binfo to be used for devirtualization of calls based on an object - represented by a declaration (i.e. a global or automatically allocated one) - or NULL if it cannot be found or is not safe. CST is expected to be an - ADDR_EXPR of such object or the function will return NULL. Currently it is - safe to use such binfo only if it has no base binfo (i.e. no ancestors). */ - -tree -gimple_extract_devirt_binfo_from_cst (tree cst) -{ - HOST_WIDE_INT offset, size, max_size; - tree base, type, expected_type, binfo; - bool last_artificial = false; - - if (!flag_devirtualize - || TREE_CODE (cst) != ADDR_EXPR - || TREE_CODE (TREE_TYPE (TREE_TYPE (cst))) != RECORD_TYPE) - return NULL_TREE; - - cst = TREE_OPERAND (cst, 0); - expected_type = TREE_TYPE (cst); - base = get_ref_base_and_extent (cst, &offset, &size, &max_size); - type = TREE_TYPE (base); - if (!DECL_P (base) - || max_size == -1 - || max_size != size - || TREE_CODE (type) != RECORD_TYPE) - return NULL_TREE; - - /* Find the sub-object the constant actually refers to and mark whether it is - an artificial one (as opposed to a user-defined one). */ - while (true) - { - HOST_WIDE_INT pos, size; - tree fld; - - if (TYPE_MAIN_VARIANT (type) == TYPE_MAIN_VARIANT (expected_type)) - break; - if (offset < 0) - return NULL_TREE; - - for (fld = TYPE_FIELDS (type); fld; fld = DECL_CHAIN (fld)) - { - if (TREE_CODE (fld) != FIELD_DECL) - continue; - - pos = int_bit_position (fld); - size = tree_low_cst (DECL_SIZE (fld), 1); - if (pos <= offset && (pos + size) > offset) - break; - } - if (!fld || TREE_CODE (TREE_TYPE (fld)) != RECORD_TYPE) - return NULL_TREE; - - last_artificial = DECL_ARTIFICIAL (fld); - type = TREE_TYPE (fld); - offset -= pos; - } - /* Artificial sub-objects are ancestors, we do not want to use them for - devirtualization, at least not here. */ - if (last_artificial) - return NULL_TREE; - binfo = TYPE_BINFO (type); - if (!binfo || BINFO_N_BASE_BINFOS (binfo) > 0) - return NULL_TREE; - else - return binfo; -} - -/* Attempt to fold a call statement referenced by the statement iterator GSI. - The statement may be replaced by another statement, e.g., if the call - simplifies to a constant value. Return true if any changes were made. - It is assumed that the operands have been previously folded. */ - -static bool -gimple_fold_call (gimple_stmt_iterator *gsi, bool inplace) -{ - gimple stmt = gsi_stmt (*gsi); - tree callee; - bool changed = false; - unsigned i; - - /* Fold *& in call arguments. */ - for (i = 0; i < gimple_call_num_args (stmt); ++i) - if (REFERENCE_CLASS_P (gimple_call_arg (stmt, i))) - { - tree tmp = maybe_fold_reference (gimple_call_arg (stmt, i), false); - if (tmp) - { - gimple_call_set_arg (stmt, i, tmp); - changed = true; - } - } - - /* Check for virtual calls that became direct calls. */ - callee = gimple_call_fn (stmt); - if (callee && TREE_CODE (callee) == OBJ_TYPE_REF) - { - if (gimple_call_addr_fndecl (OBJ_TYPE_REF_EXPR (callee)) != NULL_TREE) - { - gimple_call_set_fn (stmt, OBJ_TYPE_REF_EXPR (callee)); - changed = true; - } - else - { - tree obj = OBJ_TYPE_REF_OBJECT (callee); - tree binfo = gimple_extract_devirt_binfo_from_cst (obj); - if (binfo) - { - HOST_WIDE_INT token - = TREE_INT_CST_LOW (OBJ_TYPE_REF_TOKEN (callee)); - tree fndecl = gimple_get_virt_method_for_binfo (token, binfo); - if (fndecl) - { - gimple_call_set_fndecl (stmt, fndecl); - changed = true; - } - } - } - } - - if (inplace) - return changed; - - /* Check for builtins that CCP can handle using information not - available in the generic fold routines. */ - callee = gimple_call_fndecl (stmt); - if (callee && DECL_BUILT_IN (callee)) - { - tree result = gimple_fold_builtin (stmt); - if (result) - { - if (!update_call_from_tree (gsi, result)) - gimplify_and_update_call_from_tree (gsi, result); - changed = true; - } - } - - return changed; -} - -/* Worker for both fold_stmt and fold_stmt_inplace. The INPLACE argument - distinguishes both cases. */ - -static bool -fold_stmt_1 (gimple_stmt_iterator *gsi, bool inplace) -{ - bool changed = false; - gimple stmt = gsi_stmt (*gsi); - unsigned i; - - /* Fold the main computation performed by the statement. */ - switch (gimple_code (stmt)) - { - case GIMPLE_ASSIGN: - { - unsigned old_num_ops = gimple_num_ops (stmt); - enum tree_code subcode = gimple_assign_rhs_code (stmt); - tree lhs = gimple_assign_lhs (stmt); - tree new_rhs; - /* First canonicalize operand order. This avoids building new - trees if this is the only thing fold would later do. */ - if ((commutative_tree_code (subcode) - || commutative_ternary_tree_code (subcode)) - && tree_swap_operands_p (gimple_assign_rhs1 (stmt), - gimple_assign_rhs2 (stmt), false)) - { - tree tem = gimple_assign_rhs1 (stmt); - gimple_assign_set_rhs1 (stmt, gimple_assign_rhs2 (stmt)); - gimple_assign_set_rhs2 (stmt, tem); - changed = true; - } - new_rhs = fold_gimple_assign (gsi); - if (new_rhs - && !useless_type_conversion_p (TREE_TYPE (lhs), - TREE_TYPE (new_rhs))) - new_rhs = fold_convert (TREE_TYPE (lhs), new_rhs); - if (new_rhs - && (!inplace - || get_gimple_rhs_num_ops (TREE_CODE (new_rhs)) < old_num_ops)) - { - gimple_assign_set_rhs_from_tree (gsi, new_rhs); - changed = true; - } - break; - } - - case GIMPLE_COND: - changed |= fold_gimple_cond (stmt); - break; - - case GIMPLE_CALL: - changed |= gimple_fold_call (gsi, inplace); - break; - - case GIMPLE_ASM: - /* Fold *& in asm operands. */ - { - size_t noutputs; - const char **oconstraints; - const char *constraint; - bool allows_mem, allows_reg; - - noutputs = gimple_asm_noutputs (stmt); - oconstraints = XALLOCAVEC (const char *, noutputs); - - for (i = 0; i < gimple_asm_noutputs (stmt); ++i) - { - tree link = gimple_asm_output_op (stmt, i); - tree op = TREE_VALUE (link); - oconstraints[i] - = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link))); - if (REFERENCE_CLASS_P (op) - && (op = maybe_fold_reference (op, true)) != NULL_TREE) - { - TREE_VALUE (link) = op; - changed = true; - } - } - for (i = 0; i < gimple_asm_ninputs (stmt); ++i) - { - tree link = gimple_asm_input_op (stmt, i); - tree op = TREE_VALUE (link); - constraint - = TREE_STRING_POINTER (TREE_VALUE (TREE_PURPOSE (link))); - parse_input_constraint (&constraint, 0, 0, noutputs, 0, - oconstraints, &allows_mem, &allows_reg); - if (REFERENCE_CLASS_P (op) - && (op = maybe_fold_reference (op, !allows_reg && allows_mem)) - != NULL_TREE) - { - TREE_VALUE (link) = op; - changed = true; - } - } - } - break; - - case GIMPLE_DEBUG: - if (gimple_debug_bind_p (stmt)) - { - tree val = gimple_debug_bind_get_value (stmt); - if (val - && REFERENCE_CLASS_P (val)) - { - tree tem = maybe_fold_reference (val, false); - if (tem) - { - gimple_debug_bind_set_value (stmt, tem); - changed = true; - } - } - else if (val - && TREE_CODE (val) == ADDR_EXPR) - { - tree ref = TREE_OPERAND (val, 0); - tree tem = maybe_fold_reference (ref, false); - if (tem) - { - tem = build_fold_addr_expr_with_type (tem, TREE_TYPE (val)); - gimple_debug_bind_set_value (stmt, tem); - changed = true; - } - } - } - break; - - default:; - } - - stmt = gsi_stmt (*gsi); - - /* Fold *& on the lhs. */ - if (gimple_has_lhs (stmt)) - { - tree lhs = gimple_get_lhs (stmt); - if (lhs && REFERENCE_CLASS_P (lhs)) - { - tree new_lhs = maybe_fold_reference (lhs, true); - if (new_lhs) - { - gimple_set_lhs (stmt, new_lhs); - changed = true; - } - } - } - - return changed; -} - -/* Fold the statement pointed to by GSI. In some cases, this function may - replace the whole statement with a new one. Returns true iff folding - makes any changes. - The statement pointed to by GSI should be in valid gimple form but may - be in unfolded state as resulting from for example constant propagation - which can produce *&x = 0. */ - -bool -fold_stmt (gimple_stmt_iterator *gsi) -{ - return fold_stmt_1 (gsi, false); -} - -/* Perform the minimal folding on statement *GSI. Only operations like - *&x created by constant propagation are handled. The statement cannot - be replaced with a new one. Return true if the statement was - changed, false otherwise. - The statement *GSI should be in valid gimple form but may - be in unfolded state as resulting from for example constant propagation - which can produce *&x = 0. */ - -bool -fold_stmt_inplace (gimple_stmt_iterator *gsi) -{ - gimple stmt = gsi_stmt (*gsi); - bool changed = fold_stmt_1 (gsi, true); - gcc_assert (gsi_stmt (*gsi) == stmt); - return changed; -} - -/* Canonicalize and possibly invert the boolean EXPR; return NULL_TREE - if EXPR is null or we don't know how. - If non-null, the result always has boolean type. */ - -static tree -canonicalize_bool (tree expr, bool invert) -{ - if (!expr) - return NULL_TREE; - else if (invert) - { - if (integer_nonzerop (expr)) - return boolean_false_node; - else if (integer_zerop (expr)) - return boolean_true_node; - else if (TREE_CODE (expr) == SSA_NAME) - return fold_build2 (EQ_EXPR, boolean_type_node, expr, - build_int_cst (TREE_TYPE (expr), 0)); - else if (TREE_CODE_CLASS (TREE_CODE (expr)) == tcc_comparison) - return fold_build2 (invert_tree_comparison (TREE_CODE (expr), false), - boolean_type_node, - TREE_OPERAND (expr, 0), - TREE_OPERAND (expr, 1)); - else - return NULL_TREE; - } - else - { - if (TREE_CODE (TREE_TYPE (expr)) == BOOLEAN_TYPE) - return expr; - if (integer_nonzerop (expr)) - return boolean_true_node; - else if (integer_zerop (expr)) - return boolean_false_node; - else if (TREE_CODE (expr) == SSA_NAME) - return fold_build2 (NE_EXPR, boolean_type_node, expr, - build_int_cst (TREE_TYPE (expr), 0)); - else if (TREE_CODE_CLASS (TREE_CODE (expr)) == tcc_comparison) - return fold_build2 (TREE_CODE (expr), - boolean_type_node, - TREE_OPERAND (expr, 0), - TREE_OPERAND (expr, 1)); - else - return NULL_TREE; - } -} - -/* Check to see if a boolean expression EXPR is logically equivalent to the - comparison (OP1 CODE OP2). Check for various identities involving - SSA_NAMEs. */ - -static bool -same_bool_comparison_p (const_tree expr, enum tree_code code, - const_tree op1, const_tree op2) -{ - gimple s; - - /* The obvious case. */ - if (TREE_CODE (expr) == code - && operand_equal_p (TREE_OPERAND (expr, 0), op1, 0) - && operand_equal_p (TREE_OPERAND (expr, 1), op2, 0)) - return true; - - /* Check for comparing (name, name != 0) and the case where expr - is an SSA_NAME with a definition matching the comparison. */ - if (TREE_CODE (expr) == SSA_NAME - && TREE_CODE (TREE_TYPE (expr)) == BOOLEAN_TYPE) - { - if (operand_equal_p (expr, op1, 0)) - return ((code == NE_EXPR && integer_zerop (op2)) - || (code == EQ_EXPR && integer_nonzerop (op2))); - s = SSA_NAME_DEF_STMT (expr); - if (is_gimple_assign (s) - && gimple_assign_rhs_code (s) == code - && operand_equal_p (gimple_assign_rhs1 (s), op1, 0) - && operand_equal_p (gimple_assign_rhs2 (s), op2, 0)) - return true; - } - - /* If op1 is of the form (name != 0) or (name == 0), and the definition - of name is a comparison, recurse. */ - if (TREE_CODE (op1) == SSA_NAME - && TREE_CODE (TREE_TYPE (op1)) == BOOLEAN_TYPE) - { - s = SSA_NAME_DEF_STMT (op1); - if (is_gimple_assign (s) - && TREE_CODE_CLASS (gimple_assign_rhs_code (s)) == tcc_comparison) - { - enum tree_code c = gimple_assign_rhs_code (s); - if ((c == NE_EXPR && integer_zerop (op2)) - || (c == EQ_EXPR && integer_nonzerop (op2))) - return same_bool_comparison_p (expr, c, - gimple_assign_rhs1 (s), - gimple_assign_rhs2 (s)); - if ((c == EQ_EXPR && integer_zerop (op2)) - || (c == NE_EXPR && integer_nonzerop (op2))) - return same_bool_comparison_p (expr, - invert_tree_comparison (c, false), - gimple_assign_rhs1 (s), - gimple_assign_rhs2 (s)); - } - } - return false; -} - -/* Check to see if two boolean expressions OP1 and OP2 are logically - equivalent. */ - -static bool -same_bool_result_p (const_tree op1, const_tree op2) -{ - /* Simple cases first. */ - if (operand_equal_p (op1, op2, 0)) - return true; - - /* Check the cases where at least one of the operands is a comparison. - These are a bit smarter than operand_equal_p in that they apply some - identifies on SSA_NAMEs. */ - if (TREE_CODE_CLASS (TREE_CODE (op2)) == tcc_comparison - && same_bool_comparison_p (op1, TREE_CODE (op2), - TREE_OPERAND (op2, 0), - TREE_OPERAND (op2, 1))) - return true; - if (TREE_CODE_CLASS (TREE_CODE (op1)) == tcc_comparison - && same_bool_comparison_p (op2, TREE_CODE (op1), - TREE_OPERAND (op1, 0), - TREE_OPERAND (op1, 1))) - return true; - - /* Default case. */ - return false; -} - -/* Forward declarations for some mutually recursive functions. */ - -static tree -and_comparisons_1 (enum tree_code code1, tree op1a, tree op1b, - enum tree_code code2, tree op2a, tree op2b); -static tree -and_var_with_comparison (tree var, bool invert, - enum tree_code code2, tree op2a, tree op2b); -static tree -and_var_with_comparison_1 (gimple stmt, - enum tree_code code2, tree op2a, tree op2b); -static tree -or_comparisons_1 (enum tree_code code1, tree op1a, tree op1b, - enum tree_code code2, tree op2a, tree op2b); -static tree -or_var_with_comparison (tree var, bool invert, - enum tree_code code2, tree op2a, tree op2b); -static tree -or_var_with_comparison_1 (gimple stmt, - enum tree_code code2, tree op2a, tree op2b); - -/* Helper function for and_comparisons_1: try to simplify the AND of the - ssa variable VAR with the comparison specified by (OP2A CODE2 OP2B). - If INVERT is true, invert the value of the VAR before doing the AND. - Return NULL_EXPR if we can't simplify this to a single expression. */ - -static tree -and_var_with_comparison (tree var, bool invert, - enum tree_code code2, tree op2a, tree op2b) -{ - tree t; - gimple stmt = SSA_NAME_DEF_STMT (var); - - /* We can only deal with variables whose definitions are assignments. */ - if (!is_gimple_assign (stmt)) - return NULL_TREE; - - /* If we have an inverted comparison, apply DeMorgan's law and rewrite - !var AND (op2a code2 op2b) => !(var OR !(op2a code2 op2b)) - Then we only have to consider the simpler non-inverted cases. */ - if (invert) - t = or_var_with_comparison_1 (stmt, - invert_tree_comparison (code2, false), - op2a, op2b); - else - t = and_var_with_comparison_1 (stmt, code2, op2a, op2b); - return canonicalize_bool (t, invert); -} - -/* Try to simplify the AND of the ssa variable defined by the assignment - STMT with the comparison specified by (OP2A CODE2 OP2B). - Return NULL_EXPR if we can't simplify this to a single expression. */ - -static tree -and_var_with_comparison_1 (gimple stmt, - enum tree_code code2, tree op2a, tree op2b) -{ - tree var = gimple_assign_lhs (stmt); - tree true_test_var = NULL_TREE; - tree false_test_var = NULL_TREE; - enum tree_code innercode = gimple_assign_rhs_code (stmt); - - /* Check for identities like (var AND (var == 0)) => false. */ - if (TREE_CODE (op2a) == SSA_NAME - && TREE_CODE (TREE_TYPE (var)) == BOOLEAN_TYPE) - { - if ((code2 == NE_EXPR && integer_zerop (op2b)) - || (code2 == EQ_EXPR && integer_nonzerop (op2b))) - { - true_test_var = op2a; - if (var == true_test_var) - return var; - } - else if ((code2 == EQ_EXPR && integer_zerop (op2b)) - || (code2 == NE_EXPR && integer_nonzerop (op2b))) - { - false_test_var = op2a; - if (var == false_test_var) - return boolean_false_node; - } - } - - /* If the definition is a comparison, recurse on it. */ - if (TREE_CODE_CLASS (innercode) == tcc_comparison) - { - tree t = and_comparisons_1 (innercode, - gimple_assign_rhs1 (stmt), - gimple_assign_rhs2 (stmt), - code2, - op2a, - op2b); - if (t) - return t; - } - - /* If the definition is an AND or OR expression, we may be able to - simplify by reassociating. */ - if (TREE_CODE (TREE_TYPE (var)) == BOOLEAN_TYPE - && (innercode == BIT_AND_EXPR || innercode == BIT_IOR_EXPR)) - { - tree inner1 = gimple_assign_rhs1 (stmt); - tree inner2 = gimple_assign_rhs2 (stmt); - gimple s; - tree t; - tree partial = NULL_TREE; - bool is_and = (innercode == BIT_AND_EXPR); - - /* Check for boolean identities that don't require recursive examination - of inner1/inner2: - inner1 AND (inner1 AND inner2) => inner1 AND inner2 => var - inner1 AND (inner1 OR inner2) => inner1 - !inner1 AND (inner1 AND inner2) => false - !inner1 AND (inner1 OR inner2) => !inner1 AND inner2 - Likewise for similar cases involving inner2. */ - if (inner1 == true_test_var) - return (is_and ? var : inner1); - else if (inner2 == true_test_var) - return (is_and ? var : inner2); - else if (inner1 == false_test_var) - return (is_and - ? boolean_false_node - : and_var_with_comparison (inner2, false, code2, op2a, op2b)); - else if (inner2 == false_test_var) - return (is_and - ? boolean_false_node - : and_var_with_comparison (inner1, false, code2, op2a, op2b)); - - /* Next, redistribute/reassociate the AND across the inner tests. - Compute the first partial result, (inner1 AND (op2a code op2b)) */ - if (TREE_CODE (inner1) == SSA_NAME - && is_gimple_assign (s = SSA_NAME_DEF_STMT (inner1)) - && TREE_CODE_CLASS (gimple_assign_rhs_code (s)) == tcc_comparison - && (t = maybe_fold_and_comparisons (gimple_assign_rhs_code (s), - gimple_assign_rhs1 (s), - gimple_assign_rhs2 (s), - code2, op2a, op2b))) - { - /* Handle the AND case, where we are reassociating: - (inner1 AND inner2) AND (op2a code2 op2b) - => (t AND inner2) - If the partial result t is a constant, we win. Otherwise - continue on to try reassociating with the other inner test. */ - if (is_and) - { - if (integer_onep (t)) - return inner2; - else if (integer_zerop (t)) - return boolean_false_node; - } - - /* Handle the OR case, where we are redistributing: - (inner1 OR inner2) AND (op2a code2 op2b) - => (t OR (inner2 AND (op2a code2 op2b))) */ - else if (integer_onep (t)) - return boolean_true_node; - - /* Save partial result for later. */ - partial = t; - } - - /* Compute the second partial result, (inner2 AND (op2a code op2b)) */ - if (TREE_CODE (inner2) == SSA_NAME - && is_gimple_assign (s = SSA_NAME_DEF_STMT (inner2)) - && TREE_CODE_CLASS (gimple_assign_rhs_code (s)) == tcc_comparison - && (t = maybe_fold_and_comparisons (gimple_assign_rhs_code (s), - gimple_assign_rhs1 (s), - gimple_assign_rhs2 (s), - code2, op2a, op2b))) - { - /* Handle the AND case, where we are reassociating: - (inner1 AND inner2) AND (op2a code2 op2b) - => (inner1 AND t) */ - if (is_and) - { - if (integer_onep (t)) - return inner1; - else if (integer_zerop (t)) - return boolean_false_node; - /* If both are the same, we can apply the identity - (x AND x) == x. */ - else if (partial && same_bool_result_p (t, partial)) - return t; - } - - /* Handle the OR case. where we are redistributing: - (inner1 OR inner2) AND (op2a code2 op2b) - => (t OR (inner1 AND (op2a code2 op2b))) - => (t OR partial) */ - else - { - if (integer_onep (t)) - return boolean_true_node; - else if (partial) - { - /* We already got a simplification for the other - operand to the redistributed OR expression. The - interesting case is when at least one is false. - Or, if both are the same, we can apply the identity - (x OR x) == x. */ - if (integer_zerop (partial)) - return t; - else if (integer_zerop (t)) - return partial; - else if (same_bool_result_p (t, partial)) - return t; - } - } - } - } - return NULL_TREE; -} - -/* Try to simplify the AND of two comparisons defined by - (OP1A CODE1 OP1B) and (OP2A CODE2 OP2B), respectively. - If this can be done without constructing an intermediate value, - return the resulting tree; otherwise NULL_TREE is returned. - This function is deliberately asymmetric as it recurses on SSA_DEFs - in the first comparison but not the second. */ - -static tree -and_comparisons_1 (enum tree_code code1, tree op1a, tree op1b, - enum tree_code code2, tree op2a, tree op2b) -{ - tree truth_type = truth_type_for (TREE_TYPE (op1a)); - - /* First check for ((x CODE1 y) AND (x CODE2 y)). */ - if (operand_equal_p (op1a, op2a, 0) - && operand_equal_p (op1b, op2b, 0)) - { - /* Result will be either NULL_TREE, or a combined comparison. */ - tree t = combine_comparisons (UNKNOWN_LOCATION, - TRUTH_ANDIF_EXPR, code1, code2, - truth_type, op1a, op1b); - if (t) - return t; - } - - /* Likewise the swapped case of the above. */ - if (operand_equal_p (op1a, op2b, 0) - && operand_equal_p (op1b, op2a, 0)) - { - /* Result will be either NULL_TREE, or a combined comparison. */ - tree t = combine_comparisons (UNKNOWN_LOCATION, - TRUTH_ANDIF_EXPR, code1, - swap_tree_comparison (code2), - truth_type, op1a, op1b); - if (t) - return t; - } - - /* If both comparisons are of the same value against constants, we might - be able to merge them. */ - if (operand_equal_p (op1a, op2a, 0) - && TREE_CODE (op1b) == INTEGER_CST - && TREE_CODE (op2b) == INTEGER_CST) - { - int cmp = tree_int_cst_compare (op1b, op2b); - - /* If we have (op1a == op1b), we should either be able to - return that or FALSE, depending on whether the constant op1b - also satisfies the other comparison against op2b. */ - if (code1 == EQ_EXPR) - { - bool done = true; - bool val; - switch (code2) - { - case EQ_EXPR: val = (cmp == 0); break; - case NE_EXPR: val = (cmp != 0); break; - case LT_EXPR: val = (cmp < 0); break; - case GT_EXPR: val = (cmp > 0); break; - case LE_EXPR: val = (cmp <= 0); break; - case GE_EXPR: val = (cmp >= 0); break; - default: done = false; - } - if (done) - { - if (val) - return fold_build2 (code1, boolean_type_node, op1a, op1b); - else - return boolean_false_node; - } - } - /* Likewise if the second comparison is an == comparison. */ - else if (code2 == EQ_EXPR) - { - bool done = true; - bool val; - switch (code1) - { - case EQ_EXPR: val = (cmp == 0); break; - case NE_EXPR: val = (cmp != 0); break; - case LT_EXPR: val = (cmp > 0); break; - case GT_EXPR: val = (cmp < 0); break; - case LE_EXPR: val = (cmp >= 0); break; - case GE_EXPR: val = (cmp <= 0); break; - default: done = false; - } - if (done) - { - if (val) - return fold_build2 (code2, boolean_type_node, op2a, op2b); - else - return boolean_false_node; - } - } - - /* Same business with inequality tests. */ - else if (code1 == NE_EXPR) - { - bool val; - switch (code2) - { - case EQ_EXPR: val = (cmp != 0); break; - case NE_EXPR: val = (cmp == 0); break; - case LT_EXPR: val = (cmp >= 0); break; - case GT_EXPR: val = (cmp <= 0); break; - case LE_EXPR: val = (cmp > 0); break; - case GE_EXPR: val = (cmp < 0); break; - default: - val = false; - } - if (val) - return fold_build2 (code2, boolean_type_node, op2a, op2b); - } - else if (code2 == NE_EXPR) - { - bool val; - switch (code1) - { - case EQ_EXPR: val = (cmp == 0); break; - case NE_EXPR: val = (cmp != 0); break; - case LT_EXPR: val = (cmp <= 0); break; - case GT_EXPR: val = (cmp >= 0); break; - case LE_EXPR: val = (cmp < 0); break; - case GE_EXPR: val = (cmp > 0); break; - default: - val = false; - } - if (val) - return fold_build2 (code1, boolean_type_node, op1a, op1b); - } - - /* Chose the more restrictive of two < or <= comparisons. */ - else if ((code1 == LT_EXPR || code1 == LE_EXPR) - && (code2 == LT_EXPR || code2 == LE_EXPR)) - { - if ((cmp < 0) || (cmp == 0 && code1 == LT_EXPR)) - return fold_build2 (code1, boolean_type_node, op1a, op1b); - else - return fold_build2 (code2, boolean_type_node, op2a, op2b); - } - - /* Likewise chose the more restrictive of two > or >= comparisons. */ - else if ((code1 == GT_EXPR || code1 == GE_EXPR) - && (code2 == GT_EXPR || code2 == GE_EXPR)) - { - if ((cmp > 0) || (cmp == 0 && code1 == GT_EXPR)) - return fold_build2 (code1, boolean_type_node, op1a, op1b); - else - return fold_build2 (code2, boolean_type_node, op2a, op2b); - } - - /* Check for singleton ranges. */ - else if (cmp == 0 - && ((code1 == LE_EXPR && code2 == GE_EXPR) - || (code1 == GE_EXPR && code2 == LE_EXPR))) - return fold_build2 (EQ_EXPR, boolean_type_node, op1a, op2b); - - /* Check for disjoint ranges. */ - else if (cmp <= 0 - && (code1 == LT_EXPR || code1 == LE_EXPR) - && (code2 == GT_EXPR || code2 == GE_EXPR)) - return boolean_false_node; - else if (cmp >= 0 - && (code1 == GT_EXPR || code1 == GE_EXPR) - && (code2 == LT_EXPR || code2 == LE_EXPR)) - return boolean_false_node; - } - - /* Perhaps the first comparison is (NAME != 0) or (NAME == 1) where - NAME's definition is a truth value. See if there are any simplifications - that can be done against the NAME's definition. */ - if (TREE_CODE (op1a) == SSA_NAME - && (code1 == NE_EXPR || code1 == EQ_EXPR) - && (integer_zerop (op1b) || integer_onep (op1b))) - { - bool invert = ((code1 == EQ_EXPR && integer_zerop (op1b)) - || (code1 == NE_EXPR && integer_onep (op1b))); - gimple stmt = SSA_NAME_DEF_STMT (op1a); - switch (gimple_code (stmt)) - { - case GIMPLE_ASSIGN: - /* Try to simplify by copy-propagating the definition. */ - return and_var_with_comparison (op1a, invert, code2, op2a, op2b); - - case GIMPLE_PHI: - /* If every argument to the PHI produces the same result when - ANDed with the second comparison, we win. - Do not do this unless the type is bool since we need a bool - result here anyway. */ - if (TREE_CODE (TREE_TYPE (op1a)) == BOOLEAN_TYPE) - { - tree result = NULL_TREE; - unsigned i; - for (i = 0; i < gimple_phi_num_args (stmt); i++) - { - tree arg = gimple_phi_arg_def (stmt, i); - - /* If this PHI has itself as an argument, ignore it. - If all the other args produce the same result, - we're still OK. */ - if (arg == gimple_phi_result (stmt)) - continue; - else if (TREE_CODE (arg) == INTEGER_CST) - { - if (invert ? integer_nonzerop (arg) : integer_zerop (arg)) - { - if (!result) - result = boolean_false_node; - else if (!integer_zerop (result)) - return NULL_TREE; - } - else if (!result) - result = fold_build2 (code2, boolean_type_node, - op2a, op2b); - else if (!same_bool_comparison_p (result, - code2, op2a, op2b)) - return NULL_TREE; - } - else if (TREE_CODE (arg) == SSA_NAME - && !SSA_NAME_IS_DEFAULT_DEF (arg)) - { - tree temp; - gimple def_stmt = SSA_NAME_DEF_STMT (arg); - /* In simple cases we can look through PHI nodes, - but we have to be careful with loops. - See PR49073. */ - if (! dom_info_available_p (CDI_DOMINATORS) - || gimple_bb (def_stmt) == gimple_bb (stmt) - || dominated_by_p (CDI_DOMINATORS, - gimple_bb (def_stmt), - gimple_bb (stmt))) - return NULL_TREE; - temp = and_var_with_comparison (arg, invert, code2, - op2a, op2b); - if (!temp) - return NULL_TREE; - else if (!result) - result = temp; - else if (!same_bool_result_p (result, temp)) - return NULL_TREE; - } - else - return NULL_TREE; - } - return result; - } - - default: - break; - } - } - return NULL_TREE; -} - -/* Try to simplify the AND of two comparisons, specified by - (OP1A CODE1 OP1B) and (OP2B CODE2 OP2B), respectively. - If this can be simplified to a single expression (without requiring - introducing more SSA variables to hold intermediate values), - return the resulting tree. Otherwise return NULL_TREE. - If the result expression is non-null, it has boolean type. */ - -tree -maybe_fold_and_comparisons (enum tree_code code1, tree op1a, tree op1b, - enum tree_code code2, tree op2a, tree op2b) -{ - tree t = and_comparisons_1 (code1, op1a, op1b, code2, op2a, op2b); - if (t) - return t; - else - return and_comparisons_1 (code2, op2a, op2b, code1, op1a, op1b); -} - -/* Helper function for or_comparisons_1: try to simplify the OR of the - ssa variable VAR with the comparison specified by (OP2A CODE2 OP2B). - If INVERT is true, invert the value of VAR before doing the OR. - Return NULL_EXPR if we can't simplify this to a single expression. */ - -static tree -or_var_with_comparison (tree var, bool invert, - enum tree_code code2, tree op2a, tree op2b) -{ - tree t; - gimple stmt = SSA_NAME_DEF_STMT (var); - - /* We can only deal with variables whose definitions are assignments. */ - if (!is_gimple_assign (stmt)) - return NULL_TREE; - - /* If we have an inverted comparison, apply DeMorgan's law and rewrite - !var OR (op2a code2 op2b) => !(var AND !(op2a code2 op2b)) - Then we only have to consider the simpler non-inverted cases. */ - if (invert) - t = and_var_with_comparison_1 (stmt, - invert_tree_comparison (code2, false), - op2a, op2b); - else - t = or_var_with_comparison_1 (stmt, code2, op2a, op2b); - return canonicalize_bool (t, invert); -} - -/* Try to simplify the OR of the ssa variable defined by the assignment - STMT with the comparison specified by (OP2A CODE2 OP2B). - Return NULL_EXPR if we can't simplify this to a single expression. */ - -static tree -or_var_with_comparison_1 (gimple stmt, - enum tree_code code2, tree op2a, tree op2b) -{ - tree var = gimple_assign_lhs (stmt); - tree true_test_var = NULL_TREE; - tree false_test_var = NULL_TREE; - enum tree_code innercode = gimple_assign_rhs_code (stmt); - - /* Check for identities like (var OR (var != 0)) => true . */ - if (TREE_CODE (op2a) == SSA_NAME - && TREE_CODE (TREE_TYPE (var)) == BOOLEAN_TYPE) - { - if ((code2 == NE_EXPR && integer_zerop (op2b)) - || (code2 == EQ_EXPR && integer_nonzerop (op2b))) - { - true_test_var = op2a; - if (var == true_test_var) - return var; - } - else if ((code2 == EQ_EXPR && integer_zerop (op2b)) - || (code2 == NE_EXPR && integer_nonzerop (op2b))) - { - false_test_var = op2a; - if (var == false_test_var) - return boolean_true_node; - } - } - - /* If the definition is a comparison, recurse on it. */ - if (TREE_CODE_CLASS (innercode) == tcc_comparison) - { - tree t = or_comparisons_1 (innercode, - gimple_assign_rhs1 (stmt), - gimple_assign_rhs2 (stmt), - code2, - op2a, - op2b); - if (t) - return t; - } - - /* If the definition is an AND or OR expression, we may be able to - simplify by reassociating. */ - if (TREE_CODE (TREE_TYPE (var)) == BOOLEAN_TYPE - && (innercode == BIT_AND_EXPR || innercode == BIT_IOR_EXPR)) - { - tree inner1 = gimple_assign_rhs1 (stmt); - tree inner2 = gimple_assign_rhs2 (stmt); - gimple s; - tree t; - tree partial = NULL_TREE; - bool is_or = (innercode == BIT_IOR_EXPR); - - /* Check for boolean identities that don't require recursive examination - of inner1/inner2: - inner1 OR (inner1 OR inner2) => inner1 OR inner2 => var - inner1 OR (inner1 AND inner2) => inner1 - !inner1 OR (inner1 OR inner2) => true - !inner1 OR (inner1 AND inner2) => !inner1 OR inner2 - */ - if (inner1 == true_test_var) - return (is_or ? var : inner1); - else if (inner2 == true_test_var) - return (is_or ? var : inner2); - else if (inner1 == false_test_var) - return (is_or - ? boolean_true_node - : or_var_with_comparison (inner2, false, code2, op2a, op2b)); - else if (inner2 == false_test_var) - return (is_or - ? boolean_true_node - : or_var_with_comparison (inner1, false, code2, op2a, op2b)); - - /* Next, redistribute/reassociate the OR across the inner tests. - Compute the first partial result, (inner1 OR (op2a code op2b)) */ - if (TREE_CODE (inner1) == SSA_NAME - && is_gimple_assign (s = SSA_NAME_DEF_STMT (inner1)) - && TREE_CODE_CLASS (gimple_assign_rhs_code (s)) == tcc_comparison - && (t = maybe_fold_or_comparisons (gimple_assign_rhs_code (s), - gimple_assign_rhs1 (s), - gimple_assign_rhs2 (s), - code2, op2a, op2b))) - { - /* Handle the OR case, where we are reassociating: - (inner1 OR inner2) OR (op2a code2 op2b) - => (t OR inner2) - If the partial result t is a constant, we win. Otherwise - continue on to try reassociating with the other inner test. */ - if (is_or) - { - if (integer_onep (t)) - return boolean_true_node; - else if (integer_zerop (t)) - return inner2; - } - - /* Handle the AND case, where we are redistributing: - (inner1 AND inner2) OR (op2a code2 op2b) - => (t AND (inner2 OR (op2a code op2b))) */ - else if (integer_zerop (t)) - return boolean_false_node; - - /* Save partial result for later. */ - partial = t; - } - - /* Compute the second partial result, (inner2 OR (op2a code op2b)) */ - if (TREE_CODE (inner2) == SSA_NAME - && is_gimple_assign (s = SSA_NAME_DEF_STMT (inner2)) - && TREE_CODE_CLASS (gimple_assign_rhs_code (s)) == tcc_comparison - && (t = maybe_fold_or_comparisons (gimple_assign_rhs_code (s), - gimple_assign_rhs1 (s), - gimple_assign_rhs2 (s), - code2, op2a, op2b))) - { - /* Handle the OR case, where we are reassociating: - (inner1 OR inner2) OR (op2a code2 op2b) - => (inner1 OR t) - => (t OR partial) */ - if (is_or) - { - if (integer_zerop (t)) - return inner1; - else if (integer_onep (t)) - return boolean_true_node; - /* If both are the same, we can apply the identity - (x OR x) == x. */ - else if (partial && same_bool_result_p (t, partial)) - return t; - } - - /* Handle the AND case, where we are redistributing: - (inner1 AND inner2) OR (op2a code2 op2b) - => (t AND (inner1 OR (op2a code2 op2b))) - => (t AND partial) */ - else - { - if (integer_zerop (t)) - return boolean_false_node; - else if (partial) - { - /* We already got a simplification for the other - operand to the redistributed AND expression. The - interesting case is when at least one is true. - Or, if both are the same, we can apply the identity - (x AND x) == x. */ - if (integer_onep (partial)) - return t; - else if (integer_onep (t)) - return partial; - else if (same_bool_result_p (t, partial)) - return t; - } - } - } - } - return NULL_TREE; -} - -/* Try to simplify the OR of two comparisons defined by - (OP1A CODE1 OP1B) and (OP2A CODE2 OP2B), respectively. - If this can be done without constructing an intermediate value, - return the resulting tree; otherwise NULL_TREE is returned. - This function is deliberately asymmetric as it recurses on SSA_DEFs - in the first comparison but not the second. */ - -static tree -or_comparisons_1 (enum tree_code code1, tree op1a, tree op1b, - enum tree_code code2, tree op2a, tree op2b) -{ - tree truth_type = truth_type_for (TREE_TYPE (op1a)); - - /* First check for ((x CODE1 y) OR (x CODE2 y)). */ - if (operand_equal_p (op1a, op2a, 0) - && operand_equal_p (op1b, op2b, 0)) - { - /* Result will be either NULL_TREE, or a combined comparison. */ - tree t = combine_comparisons (UNKNOWN_LOCATION, - TRUTH_ORIF_EXPR, code1, code2, - truth_type, op1a, op1b); - if (t) - return t; - } - - /* Likewise the swapped case of the above. */ - if (operand_equal_p (op1a, op2b, 0) - && operand_equal_p (op1b, op2a, 0)) - { - /* Result will be either NULL_TREE, or a combined comparison. */ - tree t = combine_comparisons (UNKNOWN_LOCATION, - TRUTH_ORIF_EXPR, code1, - swap_tree_comparison (code2), - truth_type, op1a, op1b); - if (t) - return t; - } - - /* If both comparisons are of the same value against constants, we might - be able to merge them. */ - if (operand_equal_p (op1a, op2a, 0) - && TREE_CODE (op1b) == INTEGER_CST - && TREE_CODE (op2b) == INTEGER_CST) - { - int cmp = tree_int_cst_compare (op1b, op2b); - - /* If we have (op1a != op1b), we should either be able to - return that or TRUE, depending on whether the constant op1b - also satisfies the other comparison against op2b. */ - if (code1 == NE_EXPR) - { - bool done = true; - bool val; - switch (code2) - { - case EQ_EXPR: val = (cmp == 0); break; - case NE_EXPR: val = (cmp != 0); break; - case LT_EXPR: val = (cmp < 0); break; - case GT_EXPR: val = (cmp > 0); break; - case LE_EXPR: val = (cmp <= 0); break; - case GE_EXPR: val = (cmp >= 0); break; - default: done = false; - } - if (done) - { - if (val) - return boolean_true_node; - else - return fold_build2 (code1, boolean_type_node, op1a, op1b); - } - } - /* Likewise if the second comparison is a != comparison. */ - else if (code2 == NE_EXPR) - { - bool done = true; - bool val; - switch (code1) - { - case EQ_EXPR: val = (cmp == 0); break; - case NE_EXPR: val = (cmp != 0); break; - case LT_EXPR: val = (cmp > 0); break; - case GT_EXPR: val = (cmp < 0); break; - case LE_EXPR: val = (cmp >= 0); break; - case GE_EXPR: val = (cmp <= 0); break; - default: done = false; - } - if (done) - { - if (val) - return boolean_true_node; - else - return fold_build2 (code2, boolean_type_node, op2a, op2b); - } - } - - /* See if an equality test is redundant with the other comparison. */ - else if (code1 == EQ_EXPR) - { - bool val; - switch (code2) - { - case EQ_EXPR: val = (cmp == 0); break; - case NE_EXPR: val = (cmp != 0); break; - case LT_EXPR: val = (cmp < 0); break; - case GT_EXPR: val = (cmp > 0); break; - case LE_EXPR: val = (cmp <= 0); break; - case GE_EXPR: val = (cmp >= 0); break; - default: - val = false; - } - if (val) - return fold_build2 (code2, boolean_type_node, op2a, op2b); - } - else if (code2 == EQ_EXPR) - { - bool val; - switch (code1) - { - case EQ_EXPR: val = (cmp == 0); break; - case NE_EXPR: val = (cmp != 0); break; - case LT_EXPR: val = (cmp > 0); break; - case GT_EXPR: val = (cmp < 0); break; - case LE_EXPR: val = (cmp >= 0); break; - case GE_EXPR: val = (cmp <= 0); break; - default: - val = false; - } - if (val) - return fold_build2 (code1, boolean_type_node, op1a, op1b); - } - - /* Chose the less restrictive of two < or <= comparisons. */ - else if ((code1 == LT_EXPR || code1 == LE_EXPR) - && (code2 == LT_EXPR || code2 == LE_EXPR)) - { - if ((cmp < 0) || (cmp == 0 && code1 == LT_EXPR)) - return fold_build2 (code2, boolean_type_node, op2a, op2b); - else - return fold_build2 (code1, boolean_type_node, op1a, op1b); - } - - /* Likewise chose the less restrictive of two > or >= comparisons. */ - else if ((code1 == GT_EXPR || code1 == GE_EXPR) - && (code2 == GT_EXPR || code2 == GE_EXPR)) - { - if ((cmp > 0) || (cmp == 0 && code1 == GT_EXPR)) - return fold_build2 (code2, boolean_type_node, op2a, op2b); - else - return fold_build2 (code1, boolean_type_node, op1a, op1b); - } - - /* Check for singleton ranges. */ - else if (cmp == 0 - && ((code1 == LT_EXPR && code2 == GT_EXPR) - || (code1 == GT_EXPR && code2 == LT_EXPR))) - return fold_build2 (NE_EXPR, boolean_type_node, op1a, op2b); - - /* Check for less/greater pairs that don't restrict the range at all. */ - else if (cmp >= 0 - && (code1 == LT_EXPR || code1 == LE_EXPR) - && (code2 == GT_EXPR || code2 == GE_EXPR)) - return boolean_true_node; - else if (cmp <= 0 - && (code1 == GT_EXPR || code1 == GE_EXPR) - && (code2 == LT_EXPR || code2 == LE_EXPR)) - return boolean_true_node; - } - - /* Perhaps the first comparison is (NAME != 0) or (NAME == 1) where - NAME's definition is a truth value. See if there are any simplifications - that can be done against the NAME's definition. */ - if (TREE_CODE (op1a) == SSA_NAME - && (code1 == NE_EXPR || code1 == EQ_EXPR) - && (integer_zerop (op1b) || integer_onep (op1b))) - { - bool invert = ((code1 == EQ_EXPR && integer_zerop (op1b)) - || (code1 == NE_EXPR && integer_onep (op1b))); - gimple stmt = SSA_NAME_DEF_STMT (op1a); - switch (gimple_code (stmt)) - { - case GIMPLE_ASSIGN: - /* Try to simplify by copy-propagating the definition. */ - return or_var_with_comparison (op1a, invert, code2, op2a, op2b); - - case GIMPLE_PHI: - /* If every argument to the PHI produces the same result when - ORed with the second comparison, we win. - Do not do this unless the type is bool since we need a bool - result here anyway. */ - if (TREE_CODE (TREE_TYPE (op1a)) == BOOLEAN_TYPE) - { - tree result = NULL_TREE; - unsigned i; - for (i = 0; i < gimple_phi_num_args (stmt); i++) - { - tree arg = gimple_phi_arg_def (stmt, i); - - /* If this PHI has itself as an argument, ignore it. - If all the other args produce the same result, - we're still OK. */ - if (arg == gimple_phi_result (stmt)) - continue; - else if (TREE_CODE (arg) == INTEGER_CST) - { - if (invert ? integer_zerop (arg) : integer_nonzerop (arg)) - { - if (!result) - result = boolean_true_node; - else if (!integer_onep (result)) - return NULL_TREE; - } - else if (!result) - result = fold_build2 (code2, boolean_type_node, - op2a, op2b); - else if (!same_bool_comparison_p (result, - code2, op2a, op2b)) - return NULL_TREE; - } - else if (TREE_CODE (arg) == SSA_NAME - && !SSA_NAME_IS_DEFAULT_DEF (arg)) - { - tree temp; - gimple def_stmt = SSA_NAME_DEF_STMT (arg); - /* In simple cases we can look through PHI nodes, - but we have to be careful with loops. - See PR49073. */ - if (! dom_info_available_p (CDI_DOMINATORS) - || gimple_bb (def_stmt) == gimple_bb (stmt) - || dominated_by_p (CDI_DOMINATORS, - gimple_bb (def_stmt), - gimple_bb (stmt))) - return NULL_TREE; - temp = or_var_with_comparison (arg, invert, code2, - op2a, op2b); - if (!temp) - return NULL_TREE; - else if (!result) - result = temp; - else if (!same_bool_result_p (result, temp)) - return NULL_TREE; - } - else - return NULL_TREE; - } - return result; - } - - default: - break; - } - } - return NULL_TREE; -} - -/* Try to simplify the OR of two comparisons, specified by - (OP1A CODE1 OP1B) and (OP2B CODE2 OP2B), respectively. - If this can be simplified to a single expression (without requiring - introducing more SSA variables to hold intermediate values), - return the resulting tree. Otherwise return NULL_TREE. - If the result expression is non-null, it has boolean type. */ - -tree -maybe_fold_or_comparisons (enum tree_code code1, tree op1a, tree op1b, - enum tree_code code2, tree op2a, tree op2b) -{ - tree t = or_comparisons_1 (code1, op1a, op1b, code2, op2a, op2b); - if (t) - return t; - else - return or_comparisons_1 (code2, op2a, op2b, code1, op1a, op1b); -} - - -/* Fold STMT to a constant using VALUEIZE to valueize SSA names. - - Either NULL_TREE, a simplified but non-constant or a constant - is returned. - - ??? This should go into a gimple-fold-inline.h file to be eventually - privatized with the single valueize function used in the various TUs - to avoid the indirect function call overhead. */ - -tree -gimple_fold_stmt_to_constant_1 (gimple stmt, tree (*valueize) (tree)) -{ - location_t loc = gimple_location (stmt); - switch (gimple_code (stmt)) - { - case GIMPLE_ASSIGN: - { - enum tree_code subcode = gimple_assign_rhs_code (stmt); - - switch (get_gimple_rhs_class (subcode)) - { - case GIMPLE_SINGLE_RHS: - { - tree rhs = gimple_assign_rhs1 (stmt); - enum tree_code_class kind = TREE_CODE_CLASS (subcode); - - if (TREE_CODE (rhs) == SSA_NAME) - { - /* If the RHS is an SSA_NAME, return its known constant value, - if any. */ - return (*valueize) (rhs); - } - /* Handle propagating invariant addresses into address - operations. */ - else if (TREE_CODE (rhs) == ADDR_EXPR - && !is_gimple_min_invariant (rhs)) - { - HOST_WIDE_INT offset = 0; - tree base; - base = get_addr_base_and_unit_offset_1 (TREE_OPERAND (rhs, 0), - &offset, - valueize); - if (base - && (CONSTANT_CLASS_P (base) - || decl_address_invariant_p (base))) - return build_invariant_address (TREE_TYPE (rhs), - base, offset); - } - else if (TREE_CODE (rhs) == CONSTRUCTOR - && TREE_CODE (TREE_TYPE (rhs)) == VECTOR_TYPE - && (CONSTRUCTOR_NELTS (rhs) - == TYPE_VECTOR_SUBPARTS (TREE_TYPE (rhs)))) - { - unsigned i; - tree val, *vec; - - vec = XALLOCAVEC (tree, - TYPE_VECTOR_SUBPARTS (TREE_TYPE (rhs))); - FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (rhs), i, val) - { - val = (*valueize) (val); - if (TREE_CODE (val) == INTEGER_CST - || TREE_CODE (val) == REAL_CST - || TREE_CODE (val) == FIXED_CST) - vec[i] = val; - else - return NULL_TREE; - } - - return build_vector (TREE_TYPE (rhs), vec); - } - - if (kind == tcc_reference) - { - if ((TREE_CODE (rhs) == VIEW_CONVERT_EXPR - || TREE_CODE (rhs) == REALPART_EXPR - || TREE_CODE (rhs) == IMAGPART_EXPR) - && TREE_CODE (TREE_OPERAND (rhs, 0)) == SSA_NAME) - { - tree val = (*valueize) (TREE_OPERAND (rhs, 0)); - return fold_unary_loc (EXPR_LOCATION (rhs), - TREE_CODE (rhs), - TREE_TYPE (rhs), val); - } - else if (TREE_CODE (rhs) == BIT_FIELD_REF - && TREE_CODE (TREE_OPERAND (rhs, 0)) == SSA_NAME) - { - tree val = (*valueize) (TREE_OPERAND (rhs, 0)); - return fold_ternary_loc (EXPR_LOCATION (rhs), - TREE_CODE (rhs), - TREE_TYPE (rhs), val, - TREE_OPERAND (rhs, 1), - TREE_OPERAND (rhs, 2)); - } - else if (TREE_CODE (rhs) == MEM_REF - && TREE_CODE (TREE_OPERAND (rhs, 0)) == SSA_NAME) - { - tree val = (*valueize) (TREE_OPERAND (rhs, 0)); - if (TREE_CODE (val) == ADDR_EXPR - && is_gimple_min_invariant (val)) - { - tree tem = fold_build2 (MEM_REF, TREE_TYPE (rhs), - unshare_expr (val), - TREE_OPERAND (rhs, 1)); - if (tem) - rhs = tem; - } - } - return fold_const_aggregate_ref_1 (rhs, valueize); - } - else if (kind == tcc_declaration) - return get_symbol_constant_value (rhs); - return rhs; - } - - case GIMPLE_UNARY_RHS: - { - /* Handle unary operators that can appear in GIMPLE form. - Note that we know the single operand must be a constant, - so this should almost always return a simplified RHS. */ - tree lhs = gimple_assign_lhs (stmt); - tree op0 = (*valueize) (gimple_assign_rhs1 (stmt)); - - /* Conversions are useless for CCP purposes if they are - value-preserving. Thus the restrictions that - useless_type_conversion_p places for restrict qualification - of pointer types should not apply here. - Substitution later will only substitute to allowed places. */ - if (CONVERT_EXPR_CODE_P (subcode) - && POINTER_TYPE_P (TREE_TYPE (lhs)) - && POINTER_TYPE_P (TREE_TYPE (op0)) - && TYPE_ADDR_SPACE (TREE_TYPE (lhs)) - == TYPE_ADDR_SPACE (TREE_TYPE (op0)) - && TYPE_MODE (TREE_TYPE (lhs)) - == TYPE_MODE (TREE_TYPE (op0))) - return op0; - - return - fold_unary_ignore_overflow_loc (loc, subcode, - gimple_expr_type (stmt), op0); - } - - case GIMPLE_BINARY_RHS: - { - /* Handle binary operators that can appear in GIMPLE form. */ - tree op0 = (*valueize) (gimple_assign_rhs1 (stmt)); - tree op1 = (*valueize) (gimple_assign_rhs2 (stmt)); - - /* Translate &x + CST into an invariant form suitable for - further propagation. */ - if (gimple_assign_rhs_code (stmt) == POINTER_PLUS_EXPR - && TREE_CODE (op0) == ADDR_EXPR - && TREE_CODE (op1) == INTEGER_CST) - { - tree off = fold_convert (ptr_type_node, op1); - return build_fold_addr_expr_loc - (loc, - fold_build2 (MEM_REF, - TREE_TYPE (TREE_TYPE (op0)), - unshare_expr (op0), off)); - } - - return fold_binary_loc (loc, subcode, - gimple_expr_type (stmt), op0, op1); - } - - case GIMPLE_TERNARY_RHS: - { - /* Handle ternary operators that can appear in GIMPLE form. */ - tree op0 = (*valueize) (gimple_assign_rhs1 (stmt)); - tree op1 = (*valueize) (gimple_assign_rhs2 (stmt)); - tree op2 = (*valueize) (gimple_assign_rhs3 (stmt)); - - /* Fold embedded expressions in ternary codes. */ - if ((subcode == COND_EXPR - || subcode == VEC_COND_EXPR) - && COMPARISON_CLASS_P (op0)) - { - tree op00 = (*valueize) (TREE_OPERAND (op0, 0)); - tree op01 = (*valueize) (TREE_OPERAND (op0, 1)); - tree tem = fold_binary_loc (loc, TREE_CODE (op0), - TREE_TYPE (op0), op00, op01); - if (tem) - op0 = tem; - } - - return fold_ternary_loc (loc, subcode, - gimple_expr_type (stmt), op0, op1, op2); - } - - default: - gcc_unreachable (); - } - } - - case GIMPLE_CALL: - { - tree fn; - - if (gimple_call_internal_p (stmt)) - /* No folding yet for these functions. */ - return NULL_TREE; - - fn = (*valueize) (gimple_call_fn (stmt)); - if (TREE_CODE (fn) == ADDR_EXPR - && TREE_CODE (TREE_OPERAND (fn, 0)) == FUNCTION_DECL - && DECL_BUILT_IN (TREE_OPERAND (fn, 0))) - { - tree *args = XALLOCAVEC (tree, gimple_call_num_args (stmt)); - tree call, retval; - unsigned i; - for (i = 0; i < gimple_call_num_args (stmt); ++i) - args[i] = (*valueize) (gimple_call_arg (stmt, i)); - call = build_call_array_loc (loc, - gimple_call_return_type (stmt), - fn, gimple_call_num_args (stmt), args); - retval = fold_call_expr (EXPR_LOCATION (call), call, false); - if (retval) - /* fold_call_expr wraps the result inside a NOP_EXPR. */ - STRIP_NOPS (retval); - return retval; - } - return NULL_TREE; - } - - default: - return NULL_TREE; - } -} - -/* Fold STMT to a constant using VALUEIZE to valueize SSA names. - Returns NULL_TREE if folding to a constant is not possible, otherwise - returns a constant according to is_gimple_min_invariant. */ - -tree -gimple_fold_stmt_to_constant (gimple stmt, tree (*valueize) (tree)) -{ - tree res = gimple_fold_stmt_to_constant_1 (stmt, valueize); - if (res && is_gimple_min_invariant (res)) - return res; - return NULL_TREE; -} - - -/* The following set of functions are supposed to fold references using - their constant initializers. */ - -static tree fold_ctor_reference (tree type, tree ctor, - unsigned HOST_WIDE_INT offset, - unsigned HOST_WIDE_INT size, tree); - -/* See if we can find constructor defining value of BASE. - When we know the consructor with constant offset (such as - base is array[40] and we do know constructor of array), then - BIT_OFFSET is adjusted accordingly. - - As a special case, return error_mark_node when constructor - is not explicitly available, but it is known to be zero - such as 'static const int a;'. */ -static tree -get_base_constructor (tree base, HOST_WIDE_INT *bit_offset, - tree (*valueize)(tree)) -{ - HOST_WIDE_INT bit_offset2, size, max_size; - if (TREE_CODE (base) == MEM_REF) - { - if (!integer_zerop (TREE_OPERAND (base, 1))) - { - if (!host_integerp (TREE_OPERAND (base, 1), 0)) - return NULL_TREE; - *bit_offset += (mem_ref_offset (base).low - * BITS_PER_UNIT); - } - - if (valueize - && TREE_CODE (TREE_OPERAND (base, 0)) == SSA_NAME) - base = valueize (TREE_OPERAND (base, 0)); - if (!base || TREE_CODE (base) != ADDR_EXPR) - return NULL_TREE; - base = TREE_OPERAND (base, 0); - } - - /* Get a CONSTRUCTOR. If BASE is a VAR_DECL, get its - DECL_INITIAL. If BASE is a nested reference into another - ARRAY_REF or COMPONENT_REF, make a recursive call to resolve - the inner reference. */ - switch (TREE_CODE (base)) - { - case VAR_DECL: - if (!const_value_known_p (base)) - return NULL_TREE; - - /* Fallthru. */ - case CONST_DECL: - if (!DECL_INITIAL (base) - && (TREE_STATIC (base) || DECL_EXTERNAL (base))) - return error_mark_node; - /* Do not return an error_mark_node DECL_INITIAL. LTO uses this - as special marker (_not_ zero ...) for its own purposes. */ - if (DECL_INITIAL (base) == error_mark_node) - return NULL_TREE; - return DECL_INITIAL (base); - - case ARRAY_REF: - case COMPONENT_REF: - base = get_ref_base_and_extent (base, &bit_offset2, &size, &max_size); - if (max_size == -1 || size != max_size) - return NULL_TREE; - *bit_offset += bit_offset2; - return get_base_constructor (base, bit_offset, valueize); - - case STRING_CST: - case CONSTRUCTOR: - return base; - - default: - return NULL_TREE; - } -} - -/* CTOR is STRING_CST. Fold reference of type TYPE and size SIZE - to the memory at bit OFFSET. - - We do only simple job of folding byte accesses. */ - -static tree -fold_string_cst_ctor_reference (tree type, tree ctor, - unsigned HOST_WIDE_INT offset, - unsigned HOST_WIDE_INT size) -{ - if (INTEGRAL_TYPE_P (type) - && (TYPE_MODE (type) - == TYPE_MODE (TREE_TYPE (TREE_TYPE (ctor)))) - && (GET_MODE_CLASS (TYPE_MODE (TREE_TYPE (TREE_TYPE (ctor)))) - == MODE_INT) - && GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (TREE_TYPE (ctor)))) == 1 - && size == BITS_PER_UNIT - && !(offset % BITS_PER_UNIT)) - { - offset /= BITS_PER_UNIT; - if (offset < (unsigned HOST_WIDE_INT) TREE_STRING_LENGTH (ctor)) - return build_int_cst_type (type, (TREE_STRING_POINTER (ctor) - [offset])); - /* Folding - const char a[20]="hello"; - return a[10]; - - might lead to offset greater than string length. In this case we - know value is either initialized to 0 or out of bounds. Return 0 - in both cases. */ - return build_zero_cst (type); - } - return NULL_TREE; -} - -/* CTOR is CONSTRUCTOR of an array type. Fold reference of type TYPE and size - SIZE to the memory at bit OFFSET. */ - -static tree -fold_array_ctor_reference (tree type, tree ctor, - unsigned HOST_WIDE_INT offset, - unsigned HOST_WIDE_INT size, - tree from_decl) -{ - unsigned HOST_WIDE_INT cnt; - tree cfield, cval; - double_int low_bound, elt_size; - double_int index, max_index; - double_int access_index; - tree domain_type = NULL_TREE, index_type = NULL_TREE; - HOST_WIDE_INT inner_offset; - - /* Compute low bound and elt size. */ - if (TREE_CODE (TREE_TYPE (ctor)) == ARRAY_TYPE) - domain_type = TYPE_DOMAIN (TREE_TYPE (ctor)); - if (domain_type && TYPE_MIN_VALUE (domain_type)) - { - /* Static constructors for variably sized objects makes no sense. */ - gcc_assert (TREE_CODE (TYPE_MIN_VALUE (domain_type)) == INTEGER_CST); - index_type = TREE_TYPE (TYPE_MIN_VALUE (domain_type)); - low_bound = tree_to_double_int (TYPE_MIN_VALUE (domain_type)); - } - else - low_bound = double_int_zero; - /* Static constructors for variably sized objects makes no sense. */ - gcc_assert (TREE_CODE(TYPE_SIZE_UNIT (TREE_TYPE (TREE_TYPE (ctor)))) - == INTEGER_CST); - elt_size = - tree_to_double_int (TYPE_SIZE_UNIT (TREE_TYPE (TREE_TYPE (ctor)))); - - - /* We can handle only constantly sized accesses that are known to not - be larger than size of array element. */ - if (!TYPE_SIZE_UNIT (type) - || TREE_CODE (TYPE_SIZE_UNIT (type)) != INTEGER_CST - || elt_size.slt (tree_to_double_int (TYPE_SIZE_UNIT (type)))) - return NULL_TREE; - - /* Compute the array index we look for. */ - access_index = double_int::from_uhwi (offset / BITS_PER_UNIT) - .udiv (elt_size, TRUNC_DIV_EXPR); - access_index += low_bound; - if (index_type) - access_index = access_index.ext (TYPE_PRECISION (index_type), - TYPE_UNSIGNED (index_type)); - - /* And offset within the access. */ - inner_offset = offset % (elt_size.to_uhwi () * BITS_PER_UNIT); - - /* See if the array field is large enough to span whole access. We do not - care to fold accesses spanning multiple array indexes. */ - if (inner_offset + size > elt_size.to_uhwi () * BITS_PER_UNIT) - return NULL_TREE; - - index = low_bound - double_int_one; - if (index_type) - index = index.ext (TYPE_PRECISION (index_type), TYPE_UNSIGNED (index_type)); - - FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (ctor), cnt, cfield, cval) - { - /* Array constructor might explicitely set index, or specify range - or leave index NULL meaning that it is next index after previous - one. */ - if (cfield) - { - if (TREE_CODE (cfield) == INTEGER_CST) - max_index = index = tree_to_double_int (cfield); - else - { - gcc_assert (TREE_CODE (cfield) == RANGE_EXPR); - index = tree_to_double_int (TREE_OPERAND (cfield, 0)); - max_index = tree_to_double_int (TREE_OPERAND (cfield, 1)); - } - } - else - { - index += double_int_one; - if (index_type) - index = index.ext (TYPE_PRECISION (index_type), - TYPE_UNSIGNED (index_type)); - max_index = index; - } - - /* Do we have match? */ - if (access_index.cmp (index, 1) >= 0 - && access_index.cmp (max_index, 1) <= 0) - return fold_ctor_reference (type, cval, inner_offset, size, - from_decl); - } - /* When memory is not explicitely mentioned in constructor, - it is 0 (or out of range). */ - return build_zero_cst (type); -} - -/* CTOR is CONSTRUCTOR of an aggregate or vector. - Fold reference of type TYPE and size SIZE to the memory at bit OFFSET. */ - -static tree -fold_nonarray_ctor_reference (tree type, tree ctor, - unsigned HOST_WIDE_INT offset, - unsigned HOST_WIDE_INT size, - tree from_decl) -{ - unsigned HOST_WIDE_INT cnt; - tree cfield, cval; - - FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (ctor), cnt, cfield, - cval) - { - tree byte_offset = DECL_FIELD_OFFSET (cfield); - tree field_offset = DECL_FIELD_BIT_OFFSET (cfield); - tree field_size = DECL_SIZE (cfield); - double_int bitoffset; - double_int byte_offset_cst = tree_to_double_int (byte_offset); - double_int bits_per_unit_cst = double_int::from_uhwi (BITS_PER_UNIT); - double_int bitoffset_end, access_end; - - /* Variable sized objects in static constructors makes no sense, - but field_size can be NULL for flexible array members. */ - gcc_assert (TREE_CODE (field_offset) == INTEGER_CST - && TREE_CODE (byte_offset) == INTEGER_CST - && (field_size != NULL_TREE - ? TREE_CODE (field_size) == INTEGER_CST - : TREE_CODE (TREE_TYPE (cfield)) == ARRAY_TYPE)); - - /* Compute bit offset of the field. */ - bitoffset = tree_to_double_int (field_offset) - + byte_offset_cst * bits_per_unit_cst; - /* Compute bit offset where the field ends. */ - if (field_size != NULL_TREE) - bitoffset_end = bitoffset + tree_to_double_int (field_size); - else - bitoffset_end = double_int_zero; - - access_end = double_int::from_uhwi (offset) - + double_int::from_uhwi (size); - - /* Is there any overlap between [OFFSET, OFFSET+SIZE) and - [BITOFFSET, BITOFFSET_END)? */ - if (access_end.cmp (bitoffset, 0) > 0 - && (field_size == NULL_TREE - || double_int::from_uhwi (offset).slt (bitoffset_end))) - { - double_int inner_offset = double_int::from_uhwi (offset) - bitoffset; - /* We do have overlap. Now see if field is large enough to - cover the access. Give up for accesses spanning multiple - fields. */ - if (access_end.cmp (bitoffset_end, 0) > 0) - return NULL_TREE; - if (double_int::from_uhwi (offset).slt (bitoffset)) - return NULL_TREE; - return fold_ctor_reference (type, cval, - inner_offset.to_uhwi (), size, - from_decl); - } - } - /* When memory is not explicitely mentioned in constructor, it is 0. */ - return build_zero_cst (type); -} - -/* CTOR is value initializing memory, fold reference of type TYPE and size SIZE - to the memory at bit OFFSET. */ - -static tree -fold_ctor_reference (tree type, tree ctor, unsigned HOST_WIDE_INT offset, - unsigned HOST_WIDE_INT size, tree from_decl) -{ - tree ret; - - /* We found the field with exact match. */ - if (useless_type_conversion_p (type, TREE_TYPE (ctor)) - && !offset) - return canonicalize_constructor_val (unshare_expr (ctor), from_decl); - - /* We are at the end of walk, see if we can view convert the - result. */ - if (!AGGREGATE_TYPE_P (TREE_TYPE (ctor)) && !offset - /* VIEW_CONVERT_EXPR is defined only for matching sizes. */ - && operand_equal_p (TYPE_SIZE (type), - TYPE_SIZE (TREE_TYPE (ctor)), 0)) - { - ret = canonicalize_constructor_val (unshare_expr (ctor), from_decl); - ret = fold_unary (VIEW_CONVERT_EXPR, type, ret); - if (ret) - STRIP_NOPS (ret); - return ret; - } - if (TREE_CODE (ctor) == STRING_CST) - return fold_string_cst_ctor_reference (type, ctor, offset, size); - if (TREE_CODE (ctor) == CONSTRUCTOR) - { - - if (TREE_CODE (TREE_TYPE (ctor)) == ARRAY_TYPE - || TREE_CODE (TREE_TYPE (ctor)) == VECTOR_TYPE) - return fold_array_ctor_reference (type, ctor, offset, size, - from_decl); - else - return fold_nonarray_ctor_reference (type, ctor, offset, size, - from_decl); - } - - return NULL_TREE; -} - -/* Return the tree representing the element referenced by T if T is an - ARRAY_REF or COMPONENT_REF into constant aggregates valuezing SSA - names using VALUEIZE. Return NULL_TREE otherwise. */ - -tree -fold_const_aggregate_ref_1 (tree t, tree (*valueize) (tree)) -{ - tree ctor, idx, base; - HOST_WIDE_INT offset, size, max_size; - tree tem; - - if (TREE_THIS_VOLATILE (t)) - return NULL_TREE; - - if (TREE_CODE_CLASS (TREE_CODE (t)) == tcc_declaration) - return get_symbol_constant_value (t); - - tem = fold_read_from_constant_string (t); - if (tem) - return tem; - - switch (TREE_CODE (t)) - { - case ARRAY_REF: - case ARRAY_RANGE_REF: - /* Constant indexes are handled well by get_base_constructor. - Only special case variable offsets. - FIXME: This code can't handle nested references with variable indexes - (they will be handled only by iteration of ccp). Perhaps we can bring - get_ref_base_and_extent here and make it use a valueize callback. */ - if (TREE_CODE (TREE_OPERAND (t, 1)) == SSA_NAME - && valueize - && (idx = (*valueize) (TREE_OPERAND (t, 1))) - && TREE_CODE (idx) == INTEGER_CST) - { - tree low_bound, unit_size; - double_int doffset; - - /* If the resulting bit-offset is constant, track it. */ - if ((low_bound = array_ref_low_bound (t), - TREE_CODE (low_bound) == INTEGER_CST) - && (unit_size = array_ref_element_size (t), - host_integerp (unit_size, 1)) - && (doffset = (TREE_INT_CST (idx) - TREE_INT_CST (low_bound)) - .sext (TYPE_PRECISION (TREE_TYPE (idx))), - doffset.fits_shwi ())) - { - offset = doffset.to_shwi (); - offset *= TREE_INT_CST_LOW (unit_size); - offset *= BITS_PER_UNIT; - - base = TREE_OPERAND (t, 0); - ctor = get_base_constructor (base, &offset, valueize); - /* Empty constructor. Always fold to 0. */ - if (ctor == error_mark_node) - return build_zero_cst (TREE_TYPE (t)); - /* Out of bound array access. Value is undefined, - but don't fold. */ - if (offset < 0) - return NULL_TREE; - /* We can not determine ctor. */ - if (!ctor) - return NULL_TREE; - return fold_ctor_reference (TREE_TYPE (t), ctor, offset, - TREE_INT_CST_LOW (unit_size) - * BITS_PER_UNIT, - base); - } - } - /* Fallthru. */ - - case COMPONENT_REF: - case BIT_FIELD_REF: - case TARGET_MEM_REF: - case MEM_REF: - base = get_ref_base_and_extent (t, &offset, &size, &max_size); - ctor = get_base_constructor (base, &offset, valueize); - - /* Empty constructor. Always fold to 0. */ - if (ctor == error_mark_node) - return build_zero_cst (TREE_TYPE (t)); - /* We do not know precise address. */ - if (max_size == -1 || max_size != size) - return NULL_TREE; - /* We can not determine ctor. */ - if (!ctor) - return NULL_TREE; - - /* Out of bound array access. Value is undefined, but don't fold. */ - if (offset < 0) - return NULL_TREE; - - return fold_ctor_reference (TREE_TYPE (t), ctor, offset, size, - base); - - case REALPART_EXPR: - case IMAGPART_EXPR: - { - tree c = fold_const_aggregate_ref_1 (TREE_OPERAND (t, 0), valueize); - if (c && TREE_CODE (c) == COMPLEX_CST) - return fold_build1_loc (EXPR_LOCATION (t), - TREE_CODE (t), TREE_TYPE (t), c); - break; - } - - default: - break; - } - - return NULL_TREE; -} - -tree -fold_const_aggregate_ref (tree t) -{ - return fold_const_aggregate_ref_1 (t, NULL); -} - -/* Return a declaration of a function which an OBJ_TYPE_REF references. TOKEN - is integer form of OBJ_TYPE_REF_TOKEN of the reference expression. - KNOWN_BINFO carries the binfo describing the true type of - OBJ_TYPE_REF_OBJECT(REF). */ - -tree -gimple_get_virt_method_for_binfo (HOST_WIDE_INT token, tree known_binfo) -{ - unsigned HOST_WIDE_INT offset, size; - tree v, fn, vtable; - - vtable = v = BINFO_VTABLE (known_binfo); - /* If there is no virtual methods table, leave the OBJ_TYPE_REF alone. */ - if (!v) - return NULL_TREE; - - if (TREE_CODE (v) == POINTER_PLUS_EXPR) - { - offset = tree_low_cst (TREE_OPERAND (v, 1), 1) * BITS_PER_UNIT; - v = TREE_OPERAND (v, 0); - } - else - offset = 0; - - if (TREE_CODE (v) != ADDR_EXPR) - return NULL_TREE; - v = TREE_OPERAND (v, 0); - - if (TREE_CODE (v) != VAR_DECL - || !DECL_VIRTUAL_P (v) - || !DECL_INITIAL (v) - || DECL_INITIAL (v) == error_mark_node) - return NULL_TREE; - gcc_checking_assert (TREE_CODE (TREE_TYPE (v)) == ARRAY_TYPE); - size = tree_low_cst (TYPE_SIZE (TREE_TYPE (TREE_TYPE (v))), 1); - offset += token * size; - fn = fold_ctor_reference (TREE_TYPE (TREE_TYPE (v)), DECL_INITIAL (v), - offset, size, vtable); - if (!fn || integer_zerop (fn)) - return NULL_TREE; - gcc_assert (TREE_CODE (fn) == ADDR_EXPR - || TREE_CODE (fn) == FDESC_EXPR); - fn = TREE_OPERAND (fn, 0); - gcc_assert (TREE_CODE (fn) == FUNCTION_DECL); - - /* When cgraph node is missing and function is not public, we cannot - devirtualize. This can happen in WHOPR when the actual method - ends up in other partition, because we found devirtualization - possibility too late. */ - if (!can_refer_decl_in_current_unit_p (fn, vtable)) - return NULL_TREE; - - /* Make sure we create a cgraph node for functions we'll reference. - They can be non-existent if the reference comes from an entry - of an external vtable for example. */ - cgraph_get_create_node (fn); - - return fn; -} - -/* Return true iff VAL is a gimple expression that is known to be - non-negative. Restricted to floating-point inputs. */ - -bool -gimple_val_nonnegative_real_p (tree val) -{ - gimple def_stmt; - - gcc_assert (val && SCALAR_FLOAT_TYPE_P (TREE_TYPE (val))); - - /* Use existing logic for non-gimple trees. */ - if (tree_expr_nonnegative_p (val)) - return true; - - if (TREE_CODE (val) != SSA_NAME) - return false; - - /* Currently we look only at the immediately defining statement - to make this determination, since recursion on defining - statements of operands can lead to quadratic behavior in the - worst case. This is expected to catch almost all occurrences - in practice. It would be possible to implement limited-depth - recursion if important cases are lost. Alternatively, passes - that need this information (such as the pow/powi lowering code - in the cse_sincos pass) could be revised to provide it through - dataflow propagation. */ - - def_stmt = SSA_NAME_DEF_STMT (val); - - if (is_gimple_assign (def_stmt)) - { - tree op0, op1; - - /* See fold-const.c:tree_expr_nonnegative_p for additional - cases that could be handled with recursion. */ - - switch (gimple_assign_rhs_code (def_stmt)) - { - case ABS_EXPR: - /* Always true for floating-point operands. */ - return true; - - case MULT_EXPR: - /* True if the two operands are identical (since we are - restricted to floating-point inputs). */ - op0 = gimple_assign_rhs1 (def_stmt); - op1 = gimple_assign_rhs2 (def_stmt); - - if (op0 == op1 - || operand_equal_p (op0, op1, 0)) - return true; - - default: - return false; - } - } - else if (is_gimple_call (def_stmt)) - { - tree fndecl = gimple_call_fndecl (def_stmt); - if (fndecl - && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL) - { - tree arg1; - - switch (DECL_FUNCTION_CODE (fndecl)) - { - CASE_FLT_FN (BUILT_IN_ACOS): - CASE_FLT_FN (BUILT_IN_ACOSH): - CASE_FLT_FN (BUILT_IN_CABS): - CASE_FLT_FN (BUILT_IN_COSH): - CASE_FLT_FN (BUILT_IN_ERFC): - CASE_FLT_FN (BUILT_IN_EXP): - CASE_FLT_FN (BUILT_IN_EXP10): - CASE_FLT_FN (BUILT_IN_EXP2): - CASE_FLT_FN (BUILT_IN_FABS): - CASE_FLT_FN (BUILT_IN_FDIM): - CASE_FLT_FN (BUILT_IN_HYPOT): - CASE_FLT_FN (BUILT_IN_POW10): - return true; - - CASE_FLT_FN (BUILT_IN_SQRT): - /* sqrt(-0.0) is -0.0, and sqrt is not defined over other - nonnegative inputs. */ - if (!HONOR_SIGNED_ZEROS (TYPE_MODE (TREE_TYPE (val)))) - return true; - - break; - - CASE_FLT_FN (BUILT_IN_POWI): - /* True if the second argument is an even integer. */ - arg1 = gimple_call_arg (def_stmt, 1); - - if (TREE_CODE (arg1) == INTEGER_CST - && (TREE_INT_CST_LOW (arg1) & 1) == 0) - return true; - - break; - - CASE_FLT_FN (BUILT_IN_POW): - /* True if the second argument is an even integer-valued - real. */ - arg1 = gimple_call_arg (def_stmt, 1); - - if (TREE_CODE (arg1) == REAL_CST) - { - REAL_VALUE_TYPE c; - HOST_WIDE_INT n; - - c = TREE_REAL_CST (arg1); - n = real_to_integer (&c); - - if ((n & 1) == 0) - { - REAL_VALUE_TYPE cint; - real_from_integer (&cint, VOIDmode, n, n < 0 ? -1 : 0, 0); - if (real_identical (&c, &cint)) - return true; - } - } - - break; - - default: - return false; - } - } - } - - return false; -} |