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Diffstat (limited to 'gcc-4.8.1/gcc/tree-call-cdce.c')
| -rw-r--r-- | gcc-4.8.1/gcc/tree-call-cdce.c | 934 |
1 files changed, 0 insertions, 934 deletions
diff --git a/gcc-4.8.1/gcc/tree-call-cdce.c b/gcc-4.8.1/gcc/tree-call-cdce.c deleted file mode 100644 index 9b6186e33..000000000 --- a/gcc-4.8.1/gcc/tree-call-cdce.c +++ /dev/null @@ -1,934 +0,0 @@ -/* Conditional Dead Call Elimination pass for the GNU compiler. - Copyright (C) 2008-2013 Free Software Foundation, Inc. - Contributed by Xinliang David Li <davidxl@google.com> - -This file is part of GCC. - -GCC is free software; you can redistribute it and/or modify it -under the terms of the GNU General Public License as published by the -Free Software Foundation; either version 3, or (at your option) any -later version. - -GCC is distributed in the hope that it will be useful, but WITHOUT -ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or -FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License -for more details. - -You should have received a copy of the GNU General Public License -along with GCC; see the file COPYING3. If not see -<http://www.gnu.org/licenses/>. */ - -#include "config.h" -#include "system.h" -#include "coretypes.h" -#include "tm.h" -#include "basic-block.h" -#include "tree.h" -#include "gimple-pretty-print.h" -#include "tree-flow.h" -#include "gimple.h" -#include "tree-pass.h" -#include "flags.h" - - -/* Conditional dead call elimination - - Some builtin functions can set errno on error conditions, but they - are otherwise pure. If the result of a call to such a function is - not used, the compiler can still not eliminate the call without - powerful interprocedural analysis to prove that the errno is not - checked. However, if the conditions under which the error occurs - are known, the compiler can conditionally dead code eliminate the - calls by shrink-wrapping the semi-dead calls into the error condition: - - built_in_call (args) - ==> - if (error_cond (args)) - built_in_call (args) - - An actual simple example is : - log (x); // Mostly dead call - ==> - if (x < 0) - log (x); - With this change, call to log (x) is effectively eliminated, as - in majority of the cases, log won't be called with x out of - range. The branch is totally predictable, so the branch cost - is low. - - Note that library functions are not supposed to clear errno to zero without - error. See IEEE Std 1003.1, section 2.3 Error Numbers, and section 7.5:3 of - ISO/IEC 9899 (C99). - - The condition wrapping the builtin call is conservatively set to avoid too - aggressive (wrong) shrink wrapping. The optimization is called conditional - dead call elimination because the call is eliminated under the condition - that the input arguments would not lead to domain or range error (for - instance when x <= 0 for a log (x) call), however the chances that the error - condition is hit is very low (those builtin calls which are conditionally - dead are usually part of the C++ abstraction penalty exposed after - inlining). */ - - -/* A structure for representing input domain of - a function argument in integer. If the lower - bound is -inf, has_lb is set to false. If the - upper bound is +inf, has_ub is false. - is_lb_inclusive and is_ub_inclusive are flags - to indicate if lb and ub value are inclusive - respectively. */ - -typedef struct input_domain -{ - int lb; - int ub; - bool has_lb; - bool has_ub; - bool is_lb_inclusive; - bool is_ub_inclusive; -} inp_domain; - -/* A helper function to construct and return an input - domain object. LB is the lower bound, HAS_LB is - a boolean flag indicating if the lower bound exists, - and LB_INCLUSIVE is a boolean flag indicating if the - lower bound is inclusive or not. UB, HAS_UB, and - UB_INCLUSIVE have the same meaning, but for upper - bound of the domain. */ - -static inp_domain -get_domain (int lb, bool has_lb, bool lb_inclusive, - int ub, bool has_ub, bool ub_inclusive) -{ - inp_domain domain; - domain.lb = lb; - domain.has_lb = has_lb; - domain.is_lb_inclusive = lb_inclusive; - domain.ub = ub; - domain.has_ub = has_ub; - domain.is_ub_inclusive = ub_inclusive; - return domain; -} - -/* A helper function to check the target format for the - argument type. In this implementation, only IEEE formats - are supported. ARG is the call argument to be checked. - Returns true if the format is supported. To support other - target formats, function get_no_error_domain needs to be - enhanced to have range bounds properly computed. Since - the check is cheap (very small number of candidates - to be checked), the result is not cached for each float type. */ - -static bool -check_target_format (tree arg) -{ - tree type; - enum machine_mode mode; - const struct real_format *rfmt; - - type = TREE_TYPE (arg); - mode = TYPE_MODE (type); - rfmt = REAL_MODE_FORMAT (mode); - if ((mode == SFmode - && (rfmt == &ieee_single_format || rfmt == &mips_single_format - || rfmt == &motorola_single_format)) - || (mode == DFmode - && (rfmt == &ieee_double_format || rfmt == &mips_double_format - || rfmt == &motorola_double_format)) - /* For long double, we can not really check XFmode - which is only defined on intel platforms. - Candidate pre-selection using builtin function - code guarantees that we are checking formats - for long double modes: double, quad, and extended. */ - || (mode != SFmode && mode != DFmode - && (rfmt == &ieee_quad_format - || rfmt == &mips_quad_format - || rfmt == &ieee_extended_motorola_format - || rfmt == &ieee_extended_intel_96_format - || rfmt == &ieee_extended_intel_128_format - || rfmt == &ieee_extended_intel_96_round_53_format))) - return true; - - return false; -} - - -/* A helper function to help select calls to pow that are suitable for - conditional DCE transformation. It looks for pow calls that can be - guided with simple conditions. Such calls either have constant base - values or base values converted from integers. Returns true if - the pow call POW_CALL is a candidate. */ - -/* The maximum integer bit size for base argument of a pow call - that is suitable for shrink-wrapping transformation. */ -#define MAX_BASE_INT_BIT_SIZE 32 - -static bool -check_pow (gimple pow_call) -{ - tree base, expn; - enum tree_code bc, ec; - - if (gimple_call_num_args (pow_call) != 2) - return false; - - base = gimple_call_arg (pow_call, 0); - expn = gimple_call_arg (pow_call, 1); - - if (!check_target_format (expn)) - return false; - - bc = TREE_CODE (base); - ec = TREE_CODE (expn); - - /* Folding candidates are not interesting. - Can actually assert that it is already folded. */ - if (ec == REAL_CST && bc == REAL_CST) - return false; - - if (bc == REAL_CST) - { - /* Only handle a fixed range of constant. */ - REAL_VALUE_TYPE mv; - REAL_VALUE_TYPE bcv = TREE_REAL_CST (base); - if (REAL_VALUES_EQUAL (bcv, dconst1)) - return false; - if (REAL_VALUES_LESS (bcv, dconst1)) - return false; - real_from_integer (&mv, TYPE_MODE (TREE_TYPE (base)), 256, 0, 1); - if (REAL_VALUES_LESS (mv, bcv)) - return false; - return true; - } - else if (bc == SSA_NAME) - { - tree base_val0, type; - gimple base_def; - int bit_sz; - - /* Only handles cases where base value is converted - from integer values. */ - base_def = SSA_NAME_DEF_STMT (base); - if (gimple_code (base_def) != GIMPLE_ASSIGN) - return false; - - if (gimple_assign_rhs_code (base_def) != FLOAT_EXPR) - return false; - base_val0 = gimple_assign_rhs1 (base_def); - - type = TREE_TYPE (base_val0); - if (TREE_CODE (type) != INTEGER_TYPE) - return false; - bit_sz = TYPE_PRECISION (type); - /* If the type of the base is too wide, - the resulting shrink wrapping condition - will be too conservative. */ - if (bit_sz > MAX_BASE_INT_BIT_SIZE) - return false; - - return true; - } - else - return false; -} - -/* A helper function to help select candidate function calls that are - suitable for conditional DCE. Candidate functions must have single - valid input domain in this implementation except for pow (see check_pow). - Returns true if the function call is a candidate. */ - -static bool -check_builtin_call (gimple bcall) -{ - tree arg; - - arg = gimple_call_arg (bcall, 0); - return check_target_format (arg); -} - -/* A helper function to determine if a builtin function call is a - candidate for conditional DCE. Returns true if the builtin call - is a candidate. */ - -static bool -is_call_dce_candidate (gimple call) -{ - tree fn; - enum built_in_function fnc; - - /* Only potentially dead calls are considered. */ - if (gimple_call_lhs (call)) - return false; - - fn = gimple_call_fndecl (call); - if (!fn - || !DECL_BUILT_IN (fn) - || (DECL_BUILT_IN_CLASS (fn) != BUILT_IN_NORMAL)) - return false; - - fnc = DECL_FUNCTION_CODE (fn); - switch (fnc) - { - /* Trig functions. */ - CASE_FLT_FN (BUILT_IN_ACOS): - CASE_FLT_FN (BUILT_IN_ASIN): - /* Hyperbolic functions. */ - CASE_FLT_FN (BUILT_IN_ACOSH): - CASE_FLT_FN (BUILT_IN_ATANH): - CASE_FLT_FN (BUILT_IN_COSH): - CASE_FLT_FN (BUILT_IN_SINH): - /* Log functions. */ - CASE_FLT_FN (BUILT_IN_LOG): - CASE_FLT_FN (BUILT_IN_LOG2): - CASE_FLT_FN (BUILT_IN_LOG10): - CASE_FLT_FN (BUILT_IN_LOG1P): - /* Exp functions. */ - CASE_FLT_FN (BUILT_IN_EXP): - CASE_FLT_FN (BUILT_IN_EXP2): - CASE_FLT_FN (BUILT_IN_EXP10): - CASE_FLT_FN (BUILT_IN_EXPM1): - CASE_FLT_FN (BUILT_IN_POW10): - /* Sqrt. */ - CASE_FLT_FN (BUILT_IN_SQRT): - return check_builtin_call (call); - /* Special one: two argument pow. */ - case BUILT_IN_POW: - return check_pow (call); - default: - break; - } - - return false; -} - - -/* A helper function to generate gimple statements for - one bound comparison. ARG is the call argument to - be compared with the bound, LBUB is the bound value - in integer, TCODE is the tree_code of the comparison, - TEMP_NAME1/TEMP_NAME2 are names of the temporaries, - CONDS is a vector holding the produced GIMPLE statements, - and NCONDS points to the variable holding the number - of logical comparisons. CONDS is either empty or - a list ended with a null tree. */ - -static void -gen_one_condition (tree arg, int lbub, - enum tree_code tcode, - const char *temp_name1, - const char *temp_name2, - vec<gimple> conds, - unsigned *nconds) -{ - tree lbub_real_cst, lbub_cst, float_type; - tree temp, tempn, tempc, tempcn; - gimple stmt1, stmt2, stmt3; - - float_type = TREE_TYPE (arg); - lbub_cst = build_int_cst (integer_type_node, lbub); - lbub_real_cst = build_real_from_int_cst (float_type, lbub_cst); - - temp = create_tmp_var (float_type, temp_name1); - stmt1 = gimple_build_assign (temp, arg); - tempn = make_ssa_name (temp, stmt1); - gimple_assign_set_lhs (stmt1, tempn); - - tempc = create_tmp_var (boolean_type_node, temp_name2); - stmt2 = gimple_build_assign (tempc, - fold_build2 (tcode, - boolean_type_node, - tempn, lbub_real_cst)); - tempcn = make_ssa_name (tempc, stmt2); - gimple_assign_set_lhs (stmt2, tempcn); - - stmt3 = gimple_build_cond_from_tree (tempcn, NULL_TREE, NULL_TREE); - conds.quick_push (stmt1); - conds.quick_push (stmt2); - conds.quick_push (stmt3); - (*nconds)++; -} - -/* A helper function to generate GIMPLE statements for - out of input domain check. ARG is the call argument - to be runtime checked, DOMAIN holds the valid domain - for the given function, CONDS points to the vector - holding the result GIMPLE statements. *NCONDS is - the number of logical comparisons. This function - produces no more than two logical comparisons, one - for lower bound check, one for upper bound check. */ - -static void -gen_conditions_for_domain (tree arg, inp_domain domain, - vec<gimple> conds, - unsigned *nconds) -{ - if (domain.has_lb) - gen_one_condition (arg, domain.lb, - (domain.is_lb_inclusive - ? LT_EXPR : LE_EXPR), - "DCE_COND_LB", "DCE_COND_LB_TEST", - conds, nconds); - - if (domain.has_ub) - { - /* Now push a separator. */ - if (domain.has_lb) - conds.quick_push (NULL); - - gen_one_condition (arg, domain.ub, - (domain.is_ub_inclusive - ? GT_EXPR : GE_EXPR), - "DCE_COND_UB", "DCE_COND_UB_TEST", - conds, nconds); - } -} - - -/* A helper function to generate condition - code for the y argument in call pow (some_const, y). - See candidate selection in check_pow. Since the - candidates' base values have a limited range, - the guarded code generated for y are simple: - if (y > max_y) - pow (const, y); - Note max_y can be computed separately for each - const base, but in this implementation, we - choose to compute it using the max base - in the allowed range for the purpose of - simplicity. BASE is the constant base value, - EXPN is the expression for the exponent argument, - *CONDS is the vector to hold resulting statements, - and *NCONDS is the number of logical conditions. */ - -static void -gen_conditions_for_pow_cst_base (tree base, tree expn, - vec<gimple> conds, - unsigned *nconds) -{ - inp_domain exp_domain; - /* Validate the range of the base constant to make - sure it is consistent with check_pow. */ - REAL_VALUE_TYPE mv; - REAL_VALUE_TYPE bcv = TREE_REAL_CST (base); - gcc_assert (!REAL_VALUES_EQUAL (bcv, dconst1) - && !REAL_VALUES_LESS (bcv, dconst1)); - real_from_integer (&mv, TYPE_MODE (TREE_TYPE (base)), 256, 0, 1); - gcc_assert (!REAL_VALUES_LESS (mv, bcv)); - - exp_domain = get_domain (0, false, false, - 127, true, false); - - gen_conditions_for_domain (expn, exp_domain, - conds, nconds); -} - -/* Generate error condition code for pow calls with - non constant base values. The candidates selected - have their base argument value converted from - integer (see check_pow) value (1, 2, 4 bytes), and - the max exp value is computed based on the size - of the integer type (i.e. max possible base value). - The resulting input domain for exp argument is thus - conservative (smaller than the max value allowed by - the runtime value of the base). BASE is the integer - base value, EXPN is the expression for the exponent - argument, *CONDS is the vector to hold resulting - statements, and *NCONDS is the number of logical - conditions. */ - -static void -gen_conditions_for_pow_int_base (tree base, tree expn, - vec<gimple> conds, - unsigned *nconds) -{ - gimple base_def; - tree base_val0; - tree int_type; - tree temp, tempn; - tree cst0; - gimple stmt1, stmt2; - int bit_sz, max_exp; - inp_domain exp_domain; - - base_def = SSA_NAME_DEF_STMT (base); - base_val0 = gimple_assign_rhs1 (base_def); - int_type = TREE_TYPE (base_val0); - bit_sz = TYPE_PRECISION (int_type); - gcc_assert (bit_sz > 0 - && bit_sz <= MAX_BASE_INT_BIT_SIZE); - - /* Determine the max exp argument value according to - the size of the base integer. The max exp value - is conservatively estimated assuming IEEE754 double - precision format. */ - if (bit_sz == 8) - max_exp = 128; - else if (bit_sz == 16) - max_exp = 64; - else - { - gcc_assert (bit_sz == MAX_BASE_INT_BIT_SIZE); - max_exp = 32; - } - - /* For pow ((double)x, y), generate the following conditions: - cond 1: - temp1 = x; - if (temp1 <= 0) - - cond 2: - temp2 = y; - if (temp2 > max_exp_real_cst) */ - - /* Generate condition in reverse order -- first - the condition for the exp argument. */ - - exp_domain = get_domain (0, false, false, - max_exp, true, true); - - gen_conditions_for_domain (expn, exp_domain, - conds, nconds); - - /* Now generate condition for the base argument. - Note it does not use the helper function - gen_conditions_for_domain because the base - type is integer. */ - - /* Push a separator. */ - conds.quick_push (NULL); - - temp = create_tmp_var (int_type, "DCE_COND1"); - cst0 = build_int_cst (int_type, 0); - stmt1 = gimple_build_assign (temp, base_val0); - tempn = make_ssa_name (temp, stmt1); - gimple_assign_set_lhs (stmt1, tempn); - stmt2 = gimple_build_cond (LE_EXPR, tempn, cst0, NULL_TREE, NULL_TREE); - - conds.quick_push (stmt1); - conds.quick_push (stmt2); - (*nconds)++; -} - -/* Method to generate conditional statements for guarding conditionally - dead calls to pow. One or more statements can be generated for - each logical condition. Statement groups of different conditions - are separated by a NULL tree and they are stored in the vec - conds. The number of logical conditions are stored in *nconds. - - See C99 standard, 7.12.7.4:2, for description of pow (x, y). - The precise condition for domain errors are complex. In this - implementation, a simplified (but conservative) valid domain - for x and y are used: x is positive to avoid dom errors, while - y is smaller than a upper bound (depending on x) to avoid range - errors. Runtime code is generated to check x (if not constant) - and y against the valid domain. If it is out, jump to the call, - otherwise the call is bypassed. POW_CALL is the call statement, - *CONDS is a vector holding the resulting condition statements, - and *NCONDS is the number of logical conditions. */ - -static void -gen_conditions_for_pow (gimple pow_call, vec<gimple> conds, - unsigned *nconds) -{ - tree base, expn; - enum tree_code bc; - - gcc_checking_assert (check_pow (pow_call)); - - *nconds = 0; - - base = gimple_call_arg (pow_call, 0); - expn = gimple_call_arg (pow_call, 1); - - bc = TREE_CODE (base); - - if (bc == REAL_CST) - gen_conditions_for_pow_cst_base (base, expn, conds, nconds); - else if (bc == SSA_NAME) - gen_conditions_for_pow_int_base (base, expn, conds, nconds); - else - gcc_unreachable (); -} - -/* A helper routine to help computing the valid input domain - for a builtin function. See C99 7.12.7 for details. In this - implementation, we only handle single region domain. The - resulting region can be conservative (smaller) than the actual - one and rounded to integers. Some of the bounds are documented - in the standard, while other limit constants are computed - assuming IEEE floating point format (for SF and DF modes). - Since IEEE only sets minimum requirements for long double format, - different long double formats exist under different implementations - (e.g, 64 bit double precision (DF), 80 bit double-extended - precision (XF), and 128 bit quad precision (QF) ). For simplicity, - in this implementation, the computed bounds for long double assume - 64 bit format (DF), and are therefore conservative. Another - assumption is that single precision float type is always SF mode, - and double type is DF mode. This function is quite - implementation specific, so it may not be suitable to be part of - builtins.c. This needs to be revisited later to see if it can - be leveraged in x87 assembly expansion. */ - -static inp_domain -get_no_error_domain (enum built_in_function fnc) -{ - switch (fnc) - { - /* Trig functions: return [-1, +1] */ - CASE_FLT_FN (BUILT_IN_ACOS): - CASE_FLT_FN (BUILT_IN_ASIN): - return get_domain (-1, true, true, - 1, true, true); - /* Hyperbolic functions. */ - CASE_FLT_FN (BUILT_IN_ACOSH): - /* acosh: [1, +inf) */ - return get_domain (1, true, true, - 1, false, false); - CASE_FLT_FN (BUILT_IN_ATANH): - /* atanh: (-1, +1) */ - return get_domain (-1, true, false, - 1, true, false); - case BUILT_IN_COSHF: - case BUILT_IN_SINHF: - /* coshf: (-89, +89) */ - return get_domain (-89, true, false, - 89, true, false); - case BUILT_IN_COSH: - case BUILT_IN_SINH: - case BUILT_IN_COSHL: - case BUILT_IN_SINHL: - /* cosh: (-710, +710) */ - return get_domain (-710, true, false, - 710, true, false); - /* Log functions: (0, +inf) */ - CASE_FLT_FN (BUILT_IN_LOG): - CASE_FLT_FN (BUILT_IN_LOG2): - CASE_FLT_FN (BUILT_IN_LOG10): - return get_domain (0, true, false, - 0, false, false); - CASE_FLT_FN (BUILT_IN_LOG1P): - return get_domain (-1, true, false, - 0, false, false); - /* Exp functions. */ - case BUILT_IN_EXPF: - case BUILT_IN_EXPM1F: - /* expf: (-inf, 88) */ - return get_domain (-1, false, false, - 88, true, false); - case BUILT_IN_EXP: - case BUILT_IN_EXPM1: - case BUILT_IN_EXPL: - case BUILT_IN_EXPM1L: - /* exp: (-inf, 709) */ - return get_domain (-1, false, false, - 709, true, false); - case BUILT_IN_EXP2F: - /* exp2f: (-inf, 128) */ - return get_domain (-1, false, false, - 128, true, false); - case BUILT_IN_EXP2: - case BUILT_IN_EXP2L: - /* exp2: (-inf, 1024) */ - return get_domain (-1, false, false, - 1024, true, false); - case BUILT_IN_EXP10F: - case BUILT_IN_POW10F: - /* exp10f: (-inf, 38) */ - return get_domain (-1, false, false, - 38, true, false); - case BUILT_IN_EXP10: - case BUILT_IN_POW10: - case BUILT_IN_EXP10L: - case BUILT_IN_POW10L: - /* exp10: (-inf, 308) */ - return get_domain (-1, false, false, - 308, true, false); - /* sqrt: [0, +inf) */ - CASE_FLT_FN (BUILT_IN_SQRT): - return get_domain (0, true, true, - 0, false, false); - default: - gcc_unreachable (); - } - - gcc_unreachable (); -} - -/* The function to generate shrink wrap conditions for a partially - dead builtin call whose return value is not used anywhere, - but has to be kept live due to potential error condition. - BI_CALL is the builtin call, CONDS is the vector of statements - for condition code, NCODES is the pointer to the number of - logical conditions. Statements belonging to different logical - condition are separated by NULL tree in the vector. */ - -static void -gen_shrink_wrap_conditions (gimple bi_call, vec<gimple> conds, - unsigned int *nconds) -{ - gimple call; - tree fn; - enum built_in_function fnc; - - gcc_assert (nconds && conds.exists ()); - gcc_assert (conds.length () == 0); - gcc_assert (is_gimple_call (bi_call)); - - call = bi_call; - fn = gimple_call_fndecl (call); - gcc_assert (fn && DECL_BUILT_IN (fn)); - fnc = DECL_FUNCTION_CODE (fn); - *nconds = 0; - - if (fnc == BUILT_IN_POW) - gen_conditions_for_pow (call, conds, nconds); - else - { - tree arg; - inp_domain domain = get_no_error_domain (fnc); - *nconds = 0; - arg = gimple_call_arg (bi_call, 0); - gen_conditions_for_domain (arg, domain, conds, nconds); - } - - return; -} - - -/* Probability of the branch (to the call) is taken. */ -#define ERR_PROB 0.01 - -/* The function to shrink wrap a partially dead builtin call - whose return value is not used anywhere, but has to be kept - live due to potential error condition. Returns true if the - transformation actually happens. */ - -static bool -shrink_wrap_one_built_in_call (gimple bi_call) -{ - gimple_stmt_iterator bi_call_bsi; - basic_block bi_call_bb, join_tgt_bb, guard_bb, guard_bb0; - edge join_tgt_in_edge_from_call, join_tgt_in_edge_fall_thru; - edge bi_call_in_edge0, guard_bb_in_edge; - vec<gimple> conds; - unsigned tn_cond_stmts, nconds; - unsigned ci; - gimple cond_expr = NULL; - gimple cond_expr_start; - tree bi_call_label_decl; - gimple bi_call_label; - - conds.create (12); - gen_shrink_wrap_conditions (bi_call, conds, &nconds); - - /* This can happen if the condition generator decides - it is not beneficial to do the transformation. Just - return false and do not do any transformation for - the call. */ - if (nconds == 0) - return false; - - bi_call_bb = gimple_bb (bi_call); - - /* Now find the join target bb -- split - bi_call_bb if needed. */ - bi_call_bsi = gsi_for_stmt (bi_call); - - join_tgt_in_edge_from_call = split_block (bi_call_bb, bi_call); - bi_call_bsi = gsi_for_stmt (bi_call); - - join_tgt_bb = join_tgt_in_edge_from_call->dest; - - /* Now it is time to insert the first conditional expression - into bi_call_bb and split this bb so that bi_call is - shrink-wrapped. */ - tn_cond_stmts = conds.length (); - cond_expr = NULL; - cond_expr_start = conds[0]; - for (ci = 0; ci < tn_cond_stmts; ci++) - { - gimple c = conds[ci]; - gcc_assert (c || ci != 0); - if (!c) - break; - gsi_insert_before (&bi_call_bsi, c, GSI_SAME_STMT); - cond_expr = c; - } - nconds--; - ci++; - gcc_assert (cond_expr && gimple_code (cond_expr) == GIMPLE_COND); - - /* Now the label. */ - bi_call_label_decl = create_artificial_label (gimple_location (bi_call)); - bi_call_label = gimple_build_label (bi_call_label_decl); - gsi_insert_before (&bi_call_bsi, bi_call_label, GSI_SAME_STMT); - - bi_call_in_edge0 = split_block (bi_call_bb, cond_expr); - bi_call_in_edge0->flags &= ~EDGE_FALLTHRU; - bi_call_in_edge0->flags |= EDGE_TRUE_VALUE; - guard_bb0 = bi_call_bb; - bi_call_bb = bi_call_in_edge0->dest; - join_tgt_in_edge_fall_thru = make_edge (guard_bb0, join_tgt_bb, - EDGE_FALSE_VALUE); - - bi_call_in_edge0->probability = REG_BR_PROB_BASE * ERR_PROB; - bi_call_in_edge0->count = - apply_probability (guard_bb0->count, - bi_call_in_edge0->probability); - join_tgt_in_edge_fall_thru->probability = - inverse_probability (bi_call_in_edge0->probability); - join_tgt_in_edge_fall_thru->count = - guard_bb0->count - bi_call_in_edge0->count; - - /* Code generation for the rest of the conditions */ - guard_bb = guard_bb0; - while (nconds > 0) - { - unsigned ci0; - edge bi_call_in_edge; - gimple_stmt_iterator guard_bsi = gsi_for_stmt (cond_expr_start); - ci0 = ci; - cond_expr_start = conds[ci0]; - for (; ci < tn_cond_stmts; ci++) - { - gimple c = conds[ci]; - gcc_assert (c || ci != ci0); - if (!c) - break; - gsi_insert_before (&guard_bsi, c, GSI_SAME_STMT); - cond_expr = c; - } - nconds--; - ci++; - gcc_assert (cond_expr && gimple_code (cond_expr) == GIMPLE_COND); - guard_bb_in_edge = split_block (guard_bb, cond_expr); - guard_bb_in_edge->flags &= ~EDGE_FALLTHRU; - guard_bb_in_edge->flags |= EDGE_FALSE_VALUE; - - bi_call_in_edge = make_edge (guard_bb, bi_call_bb, EDGE_TRUE_VALUE); - - bi_call_in_edge->probability = REG_BR_PROB_BASE * ERR_PROB; - bi_call_in_edge->count = - apply_probability (guard_bb->count, - bi_call_in_edge->probability); - guard_bb_in_edge->probability = - inverse_probability (bi_call_in_edge->probability); - guard_bb_in_edge->count = guard_bb->count - bi_call_in_edge->count; - } - - conds.release (); - if (dump_file && (dump_flags & TDF_DETAILS)) - { - location_t loc; - loc = gimple_location (bi_call); - fprintf (dump_file, - "%s:%d: note: function call is shrink-wrapped" - " into error conditions.\n", - LOCATION_FILE (loc), LOCATION_LINE (loc)); - } - - return true; -} - -/* The top level function for conditional dead code shrink - wrapping transformation. */ - -static bool -shrink_wrap_conditional_dead_built_in_calls (vec<gimple> calls) -{ - bool changed = false; - unsigned i = 0; - - unsigned n = calls.length (); - if (n == 0) - return false; - - for (; i < n ; i++) - { - gimple bi_call = calls[i]; - changed |= shrink_wrap_one_built_in_call (bi_call); - } - - return changed; -} - -/* Pass entry points. */ - -static unsigned int -tree_call_cdce (void) -{ - basic_block bb; - gimple_stmt_iterator i; - bool something_changed = false; - vec<gimple> cond_dead_built_in_calls = vNULL; - FOR_EACH_BB (bb) - { - /* Collect dead call candidates. */ - for (i = gsi_start_bb (bb); !gsi_end_p (i); gsi_next (&i)) - { - gimple stmt = gsi_stmt (i); - if (is_gimple_call (stmt) - && is_call_dce_candidate (stmt)) - { - if (dump_file && (dump_flags & TDF_DETAILS)) - { - fprintf (dump_file, "Found conditional dead call: "); - print_gimple_stmt (dump_file, stmt, 0, TDF_SLIM); - fprintf (dump_file, "\n"); - } - if (!cond_dead_built_in_calls.exists ()) - cond_dead_built_in_calls.create (64); - cond_dead_built_in_calls.safe_push (stmt); - } - } - } - - if (!cond_dead_built_in_calls.exists ()) - return 0; - - something_changed - = shrink_wrap_conditional_dead_built_in_calls (cond_dead_built_in_calls); - - cond_dead_built_in_calls.release (); - - if (something_changed) - { - free_dominance_info (CDI_DOMINATORS); - free_dominance_info (CDI_POST_DOMINATORS); - /* As we introduced new control-flow we need to insert PHI-nodes - for the call-clobbers of the remaining call. */ - mark_virtual_operands_for_renaming (cfun); - return TODO_update_ssa; - } - - return 0; -} - -static bool -gate_call_cdce (void) -{ - /* The limit constants used in the implementation - assume IEEE floating point format. Other formats - can be supported in the future if needed. */ - return flag_tree_builtin_call_dce != 0 && optimize_function_for_speed_p (cfun); -} - -struct gimple_opt_pass pass_call_cdce = -{ - { - GIMPLE_PASS, - "cdce", /* name */ - OPTGROUP_NONE, /* optinfo_flags */ - gate_call_cdce, /* gate */ - tree_call_cdce, /* execute */ - NULL, /* sub */ - NULL, /* next */ - 0, /* static_pass_number */ - TV_TREE_CALL_CDCE, /* tv_id */ - PROP_cfg | PROP_ssa, /* properties_required */ - 0, /* properties_provided */ - 0, /* properties_destroyed */ - 0, /* todo_flags_start */ - TODO_verify_ssa /* todo_flags_finish */ - } -}; |