X-Git-Url: http://git.sourceforge.jp/view?p=pf3gnuchains%2Fgcc-fork.git;a=blobdiff_plain;f=gcc%2Fpredict.c;h=c6e933f510110a6b7adb2662267b2fcc3e7faea4;hp=097cfb860703c66a61f134a47d49cb9352177225;hb=393c778cf00fccafc74eda89877de0899f522c36;hpb=f6a0d06ff9a23783bfe5dd6f75336f8832834bc3 diff --git a/gcc/predict.c b/gcc/predict.c index 097cfb86070..c6e933f5101 100644 --- a/gcc/predict.c +++ b/gcc/predict.c @@ -1,12 +1,12 @@ /* Branch prediction routines for the GNU compiler. - Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005 + Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005, 2007, 2008 Free Software Foundation, Inc. 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 2, or (at your option) any later +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 @@ -15,9 +15,8 @@ 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 COPYING. If not, write to the Free -Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA -02110-1301, USA. */ +along with GCC; see the file COPYING3. If not see +. */ /* References: @@ -60,24 +59,27 @@ Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA #include "timevar.h" #include "tree-scalar-evolution.h" #include "cfgloop.h" +#include "pointer-set.h" /* real constants: 0, 1, 1-1/REG_BR_PROB_BASE, REG_BR_PROB_BASE, 1/REG_BR_PROB_BASE, 0.5, BB_FREQ_MAX. */ static sreal real_zero, real_one, real_almost_one, real_br_prob_base, real_inv_br_prob_base, real_one_half, real_bb_freq_max; -/* Random guesstimation given names. */ -#define PROB_VERY_UNLIKELY (REG_BR_PROB_BASE / 100 - 1) +/* Random guesstimation given names. + PROV_VERY_UNLIKELY should be small enough so basic block predicted + by it gets bellow HOT_BB_FREQUENCY_FRANCTION. */ +#define PROB_VERY_UNLIKELY (REG_BR_PROB_BASE / 2000 - 1) #define PROB_EVEN (REG_BR_PROB_BASE / 2) #define PROB_VERY_LIKELY (REG_BR_PROB_BASE - PROB_VERY_UNLIKELY) #define PROB_ALWAYS (REG_BR_PROB_BASE) static void combine_predictions_for_insn (rtx, basic_block); static void dump_prediction (FILE *, enum br_predictor, int, basic_block, int); -static void predict_paths_leading_to (basic_block, int *, enum br_predictor, enum prediction); +static void predict_paths_leading_to (basic_block, enum br_predictor, enum prediction); static void compute_function_frequency (void); static void choose_function_section (void); -static bool can_predict_insn_p (rtx); +static bool can_predict_insn_p (const_rtx); /* Information we hold about each branch predictor. Filled using information from predict.def. */ @@ -107,16 +109,11 @@ static const struct predictor_info predictor_info[]= { }; #undef DEF_PREDICTOR -/* Return true in case BB can be CPU intensive and should be optimized - for maximal performance. */ +/* Return TRUE if frequency FREQ is considered to be hot. */ -bool -maybe_hot_bb_p (basic_block bb) +static inline bool +maybe_hot_frequency_p (int freq) { - if (profile_info && flag_branch_probabilities - && (bb->count - < profile_info->sum_max / PARAM_VALUE (HOT_BB_COUNT_FRACTION))) - return false; if (!profile_info || !flag_branch_probabilities) { if (cfun->function_frequency == FUNCTION_FREQUENCY_UNLIKELY_EXECUTED) @@ -124,31 +121,73 @@ maybe_hot_bb_p (basic_block bb) if (cfun->function_frequency == FUNCTION_FREQUENCY_HOT) return true; } - if (bb->frequency < BB_FREQ_MAX / PARAM_VALUE (HOT_BB_FREQUENCY_FRACTION)) + if (profile_status == PROFILE_ABSENT) + return true; + if (freq < BB_FREQ_MAX / PARAM_VALUE (HOT_BB_FREQUENCY_FRACTION)) return false; return true; } -/* Return true in case BB is cold and should be optimized for size. */ +/* Return TRUE if frequency FREQ is considered to be hot. */ + +static inline bool +maybe_hot_count_p (gcov_type count) +{ + if (profile_status != PROFILE_READ) + return true; + /* Code executed at most once is not hot. */ + if (profile_info->runs >= count) + return false; + return (count + > profile_info->sum_max / PARAM_VALUE (HOT_BB_COUNT_FRACTION)); +} + +/* Return true in case BB can be CPU intensive and should be optimized + for maximal performance. */ + +bool +maybe_hot_bb_p (const_basic_block bb) +{ + if (profile_status == PROFILE_READ) + return maybe_hot_count_p (bb->count); + return maybe_hot_frequency_p (bb->frequency); +} + +/* Return true if the call can be hot. */ bool -probably_cold_bb_p (basic_block bb) +cgraph_maybe_hot_edge_p (struct cgraph_edge *edge) { if (profile_info && flag_branch_probabilities - && (bb->count - < profile_info->sum_max / PARAM_VALUE (HOT_BB_COUNT_FRACTION))) - return true; - if ((!profile_info || !flag_branch_probabilities) - && cfun->function_frequency == FUNCTION_FREQUENCY_UNLIKELY_EXECUTED) - return true; - if (bb->frequency < BB_FREQ_MAX / PARAM_VALUE (HOT_BB_FREQUENCY_FRACTION)) + && (edge->count + <= profile_info->sum_max / PARAM_VALUE (HOT_BB_COUNT_FRACTION))) + return false; + if (lookup_attribute ("cold", DECL_ATTRIBUTES (edge->callee->decl)) + || lookup_attribute ("cold", DECL_ATTRIBUTES (edge->caller->decl))) + return false; + if (lookup_attribute ("hot", DECL_ATTRIBUTES (edge->caller->decl))) return true; - return false; + if (flag_guess_branch_prob + && edge->frequency < (CGRAPH_FREQ_MAX + / PARAM_VALUE (HOT_BB_FREQUENCY_FRACTION))) + return false; + return true; +} + +/* Return true in case BB can be CPU intensive and should be optimized + for maximal performance. */ + +bool +maybe_hot_edge_p (edge e) +{ + if (profile_status == PROFILE_READ) + return maybe_hot_count_p (e->count); + return maybe_hot_frequency_p (EDGE_FREQUENCY (e)); } /* Return true in case BB is probably never executed. */ bool -probably_never_executed_bb_p (basic_block bb) +probably_never_executed_bb_p (const_basic_block bb) { if (profile_info && flag_branch_probabilities) return ((bb->count + profile_info->runs / 2) / profile_info->runs) == 0; @@ -158,11 +197,169 @@ probably_never_executed_bb_p (basic_block bb) return false; } +/* Return true when current function should always be optimized for size. */ + +bool +optimize_function_for_size_p (struct function *fun) +{ + return (optimize_size + || (fun && (fun->function_frequency + == FUNCTION_FREQUENCY_UNLIKELY_EXECUTED))); +} + +/* Return true when current function should always be optimized for speed. */ + +bool +optimize_function_for_speed_p (struct function *fun) +{ + return !optimize_function_for_size_p (fun); +} + +/* Return TRUE when BB should be optimized for size. */ + +bool +optimize_bb_for_size_p (const_basic_block bb) +{ + return optimize_function_for_size_p (cfun) || !maybe_hot_bb_p (bb); +} + +/* Return TRUE when BB should be optimized for speed. */ + +bool +optimize_bb_for_speed_p (const_basic_block bb) +{ + return !optimize_bb_for_size_p (bb); +} + +/* Return TRUE when BB should be optimized for size. */ + +bool +optimize_edge_for_size_p (edge e) +{ + return optimize_function_for_size_p (cfun) || !maybe_hot_edge_p (e); +} + +/* Return TRUE when BB should be optimized for speed. */ + +bool +optimize_edge_for_speed_p (edge e) +{ + return !optimize_edge_for_size_p (e); +} + +/* Return TRUE when BB should be optimized for size. */ + +bool +optimize_insn_for_size_p (void) +{ + return optimize_function_for_size_p (cfun) || !crtl->maybe_hot_insn_p; +} + +/* Return TRUE when BB should be optimized for speed. */ + +bool +optimize_insn_for_speed_p (void) +{ + return !optimize_insn_for_size_p (); +} + +/* Return TRUE when LOOP should be optimized for size. */ + +bool +optimize_loop_for_size_p (struct loop *loop) +{ + return optimize_bb_for_size_p (loop->header); +} + +/* Return TRUE when LOOP should be optimized for speed. */ + +bool +optimize_loop_for_speed_p (struct loop *loop) +{ + return optimize_bb_for_speed_p (loop->header); +} + +/* Return TRUE when LOOP nest should be optimized for speed. */ + +bool +optimize_loop_nest_for_speed_p (struct loop *loop) +{ + struct loop *l = loop; + if (optimize_loop_for_speed_p (loop)) + return true; + l = loop->inner; + while (l && l != loop) + { + if (optimize_loop_for_speed_p (l)) + return true; + if (l->inner) + l = l->inner; + else if (l->next) + l = l->next; + else + { + while (l != loop && !l->next) + l = loop_outer (l); + if (l != loop) + l = l->next; + } + } + return false; +} + +/* Return TRUE when LOOP nest should be optimized for size. */ + +bool +optimize_loop_nest_for_size_p (struct loop *loop) +{ + return !optimize_loop_nest_for_speed_p (loop); +} + +/* Return true when edge E is likely to be well predictable by branch + predictor. */ + +bool +predictable_edge_p (edge e) +{ + if (profile_status == PROFILE_ABSENT) + return false; + if ((e->probability + <= PARAM_VALUE (PARAM_PREDICTABLE_BRANCH_OUTCOME) * REG_BR_PROB_BASE / 100) + || (REG_BR_PROB_BASE - e->probability + <= PARAM_VALUE (PARAM_PREDICTABLE_BRANCH_OUTCOME) * REG_BR_PROB_BASE / 100)) + return true; + return false; +} + + +/* Set RTL expansion for BB profile. */ + +void +rtl_profile_for_bb (basic_block bb) +{ + crtl->maybe_hot_insn_p = maybe_hot_bb_p (bb); +} + +/* Set RTL expansion for edge profile. */ + +void +rtl_profile_for_edge (edge e) +{ + crtl->maybe_hot_insn_p = maybe_hot_edge_p (e); +} + +/* Set RTL expansion to default mode (i.e. when profile info is not known). */ +void +default_rtl_profile (void) +{ + crtl->maybe_hot_insn_p = true; +} + /* Return true if the one of outgoing edges is already predicted by PREDICTOR. */ bool -rtl_predicted_by_p (basic_block bb, enum br_predictor predictor) +rtl_predicted_by_p (const_basic_block bb, enum br_predictor predictor) { rtx note; if (!INSN_P (BB_END (bb))) @@ -174,14 +371,24 @@ rtl_predicted_by_p (basic_block bb, enum br_predictor predictor) return false; } +/* This map contains for a basic block the list of predictions for the + outgoing edges. */ + +static struct pointer_map_t *bb_predictions; + /* Return true if the one of outgoing edges is already predicted by PREDICTOR. */ bool -tree_predicted_by_p (basic_block bb, enum br_predictor predictor) +gimple_predicted_by_p (const_basic_block bb, enum br_predictor predictor) { struct edge_prediction *i; - for (i = bb->predictions; i; i = i->ep_next) + void **preds = pointer_map_contains (bb_predictions, bb); + + if (!preds) + return false; + + for (i = (struct edge_prediction *) *preds; i; i = i->ep_next) if (i->ep_predictor == predictor) return true; return false; @@ -213,14 +420,14 @@ probability_reliable_p (int prob) /* Same predicate as above, working on edges. */ bool -edge_probability_reliable_p (edge e) +edge_probability_reliable_p (const_edge e) { return probability_reliable_p (e->probability); } /* Same predicate as edge_probability_reliable_p, working on notes. */ bool -br_prob_note_reliable_p (rtx note) +br_prob_note_reliable_p (const_rtx note) { gcc_assert (REG_NOTE_KIND (note) == REG_BR_PROB); return probability_reliable_p (INTVAL (XEXP (note, 0))); @@ -233,12 +440,10 @@ predict_insn (rtx insn, enum br_predictor predictor, int probability) if (!flag_guess_branch_prob) return; - REG_NOTES (insn) - = gen_rtx_EXPR_LIST (REG_BR_PRED, - gen_rtx_CONCAT (VOIDmode, - GEN_INT ((int) predictor), - GEN_INT ((int) probability)), - REG_NOTES (insn)); + add_reg_note (insn, REG_BR_PRED, + gen_rtx_CONCAT (VOIDmode, + GEN_INT ((int) predictor), + GEN_INT ((int) probability))); } /* Predict insn by given predictor. */ @@ -277,16 +482,17 @@ rtl_predict_edge (edge e, enum br_predictor predictor, int probability) /* Predict edge E with the given PROBABILITY. */ void -tree_predict_edge (edge e, enum br_predictor predictor, int probability) +gimple_predict_edge (edge e, enum br_predictor predictor, int probability) { gcc_assert (profile_status != PROFILE_GUESSED); if ((e->src != ENTRY_BLOCK_PTR && EDGE_COUNT (e->src->succs) > 1) && flag_guess_branch_prob && optimize) { - struct edge_prediction *i = ggc_alloc (sizeof (struct edge_prediction)); + struct edge_prediction *i = XNEW (struct edge_prediction); + void **preds = pointer_map_insert (bb_predictions, e->src); - i->ep_next = e->src->predictions; - e->src->predictions = i; + i->ep_next = (struct edge_prediction *) *preds; + *preds = i; i->ep_probability = probability; i->ep_predictor = predictor; i->ep_edge = e; @@ -298,24 +504,56 @@ tree_predict_edge (edge e, enum br_predictor predictor, int probability) void remove_predictions_associated_with_edge (edge e) { - if (e->src->predictions) + void **preds; + + if (!bb_predictions) + return; + + preds = pointer_map_contains (bb_predictions, e->src); + + if (preds) { - struct edge_prediction **prediction = &e->src->predictions; + struct edge_prediction **prediction = (struct edge_prediction **) preds; + struct edge_prediction *next; + while (*prediction) { if ((*prediction)->ep_edge == e) - *prediction = (*prediction)->ep_next; + { + next = (*prediction)->ep_next; + free (*prediction); + *prediction = next; + } else prediction = &((*prediction)->ep_next); } } } +/* Clears the list of predictions stored for BB. */ + +static void +clear_bb_predictions (basic_block bb) +{ + void **preds = pointer_map_contains (bb_predictions, bb); + struct edge_prediction *pred, *next; + + if (!preds) + return; + + for (pred = (struct edge_prediction *) *preds; pred; pred = next) + { + next = pred->ep_next; + free (pred); + } + *preds = NULL; +} + /* Return true when we can store prediction on insn INSN. At the moment we represent predictions only on conditional jumps, not at computed jump or other complicated cases. */ static bool -can_predict_insn_p (rtx insn) +can_predict_insn_p (const_rtx insn) { return (JUMP_P (insn) && any_condjump_p (insn) @@ -498,9 +736,7 @@ combine_predictions_for_insn (rtx insn, basic_block bb) if (!prob_note) { - REG_NOTES (insn) - = gen_rtx_EXPR_LIST (REG_BR_PROB, - GEN_INT (combined_probability), REG_NOTES (insn)); + add_reg_note (insn, REG_BR_PROB, GEN_INT (combined_probability)); /* Save the prediction into CFG in case we are seeing non-degenerated conditional jump. */ @@ -538,6 +774,7 @@ combine_predictions_for_bb (basic_block bb) int nedges = 0; edge e, first = NULL, second = NULL; edge_iterator ei; + void **preds; FOR_EACH_EDGE (e, ei, bb->succs) if (!(e->flags & (EDGE_EH | EDGE_FAKE))) @@ -559,7 +796,7 @@ combine_predictions_for_bb (basic_block bb) { if (!bb->count) set_even_probabilities (bb); - bb->predictions = NULL; + clear_bb_predictions (bb); if (dump_file) fprintf (dump_file, "%i edges in bb %i predicted to even probabilities\n", nedges, bb->index); @@ -569,31 +806,36 @@ combine_predictions_for_bb (basic_block bb) if (dump_file) fprintf (dump_file, "Predictions for bb %i\n", bb->index); - /* We implement "first match" heuristics and use probability guessed - by predictor with smallest index. */ - for (pred = bb->predictions; pred; pred = pred->ep_next) + preds = pointer_map_contains (bb_predictions, bb); + if (preds) { - int predictor = pred->ep_predictor; - int probability = pred->ep_probability; + /* We implement "first match" heuristics and use probability guessed + by predictor with smallest index. */ + for (pred = (struct edge_prediction *) *preds; pred; pred = pred->ep_next) + { + int predictor = pred->ep_predictor; + int probability = pred->ep_probability; - if (pred->ep_edge != first) - probability = REG_BR_PROB_BASE - probability; + if (pred->ep_edge != first) + probability = REG_BR_PROB_BASE - probability; - found = true; - if (best_predictor > predictor) - best_probability = probability, best_predictor = predictor; + found = true; + if (best_predictor > predictor) + best_probability = probability, best_predictor = predictor; - d = (combined_probability * probability - + (REG_BR_PROB_BASE - combined_probability) - * (REG_BR_PROB_BASE - probability)); + d = (combined_probability * probability + + (REG_BR_PROB_BASE - combined_probability) + * (REG_BR_PROB_BASE - probability)); - /* Use FP math to avoid overflows of 32bit integers. */ - if (d == 0) - /* If one probability is 0% and one 100%, avoid division by zero. */ - combined_probability = REG_BR_PROB_BASE / 2; - else - combined_probability = (((double) combined_probability) * probability - * REG_BR_PROB_BASE / d + 0.5); + /* Use FP math to avoid overflows of 32bit integers. */ + if (d == 0) + /* If one probability is 0% and one 100%, avoid division by zero. */ + combined_probability = REG_BR_PROB_BASE / 2; + else + combined_probability = (((double) combined_probability) + * probability + * REG_BR_PROB_BASE / d + 0.5); + } } /* Decide which heuristic to use. In case we didn't match anything, @@ -617,17 +859,20 @@ combine_predictions_for_bb (basic_block bb) combined_probability = best_probability; dump_prediction (dump_file, PRED_COMBINED, combined_probability, bb, true); - for (pred = bb->predictions; pred; pred = pred->ep_next) + if (preds) { - int predictor = pred->ep_predictor; - int probability = pred->ep_probability; + for (pred = (struct edge_prediction *) *preds; pred; pred = pred->ep_next) + { + int predictor = pred->ep_predictor; + int probability = pred->ep_probability; - if (pred->ep_edge != EDGE_SUCC (bb, 0)) - probability = REG_BR_PROB_BASE - probability; - dump_prediction (dump_file, predictor, probability, bb, - !first_match || best_predictor == predictor); + if (pred->ep_edge != EDGE_SUCC (bb, 0)) + probability = REG_BR_PROB_BASE - probability; + dump_prediction (dump_file, predictor, probability, bb, + !first_match || best_predictor == predictor); + } } - bb->predictions = NULL; + clear_bb_predictions (bb); if (!bb->count) { @@ -879,36 +1124,38 @@ guess_outgoing_edge_probabilities (basic_block bb) combine_predictions_for_insn (BB_END (bb), bb); } -/* Return constant EXPR will likely have at execution time, NULL if unknown. - The function is used by builtin_expect branch predictor so the evidence - must come from this construct and additional possible constant folding. - - We may want to implement more involved value guess (such as value range - propagation based prediction), but such tricks shall go to new - implementation. */ +static tree expr_expected_value (tree, bitmap); + +/* Helper function for expr_expected_value. */ static tree -expr_expected_value (tree expr, bitmap visited) +expr_expected_value_1 (tree type, tree op0, enum tree_code code, tree op1, bitmap visited) { - if (TREE_CONSTANT (expr)) - return expr; - else if (TREE_CODE (expr) == SSA_NAME) + gimple def; + + if (get_gimple_rhs_class (code) == GIMPLE_SINGLE_RHS) { - tree def = SSA_NAME_DEF_STMT (expr); + if (TREE_CONSTANT (op0)) + return op0; + + if (code != SSA_NAME) + return NULL_TREE; + + def = SSA_NAME_DEF_STMT (op0); /* If we were already here, break the infinite cycle. */ - if (bitmap_bit_p (visited, SSA_NAME_VERSION (expr))) + if (bitmap_bit_p (visited, SSA_NAME_VERSION (op0))) return NULL; - bitmap_set_bit (visited, SSA_NAME_VERSION (expr)); + bitmap_set_bit (visited, SSA_NAME_VERSION (op0)); - if (TREE_CODE (def) == PHI_NODE) + if (gimple_code (def) == GIMPLE_PHI) { /* All the arguments of the PHI node must have the same constant length. */ - int i; + int i, n = gimple_phi_num_args (def); tree val = NULL, new_val; - for (i = 0; i < PHI_NUM_ARGS (def); i++) + for (i = 0; i < n; i++) { tree arg = PHI_ARG_DEF (def, i); @@ -931,111 +1178,157 @@ expr_expected_value (tree expr, bitmap visited) } return val; } - if (TREE_CODE (def) != GIMPLE_MODIFY_STMT - || GIMPLE_STMT_OPERAND (def, 0) != expr) - return NULL; - return expr_expected_value (GIMPLE_STMT_OPERAND (def, 1), visited); - } - else if (TREE_CODE (expr) == CALL_EXPR) - { - tree decl = get_callee_fndecl (expr); - if (!decl) - return NULL; - if (DECL_BUILT_IN_CLASS (decl) == BUILT_IN_NORMAL - && DECL_FUNCTION_CODE (decl) == BUILT_IN_EXPECT) + if (is_gimple_assign (def)) { - tree val; + if (gimple_assign_lhs (def) != op0) + return NULL; - if (call_expr_nargs (expr) != 2) + return expr_expected_value_1 (TREE_TYPE (gimple_assign_lhs (def)), + gimple_assign_rhs1 (def), + gimple_assign_rhs_code (def), + gimple_assign_rhs2 (def), + visited); + } + + if (is_gimple_call (def)) + { + tree decl = gimple_call_fndecl (def); + if (!decl) return NULL; - val = CALL_EXPR_ARG (expr, 0); - if (TREE_CONSTANT (val)) - return val; - return CALL_EXPR_ARG (expr, 1); + if (DECL_BUILT_IN_CLASS (decl) == BUILT_IN_NORMAL + && DECL_FUNCTION_CODE (decl) == BUILT_IN_EXPECT) + { + tree val; + + if (gimple_call_num_args (def) != 2) + return NULL; + val = gimple_call_arg (def, 0); + if (TREE_CONSTANT (val)) + return val; + return gimple_call_arg (def, 1); + } } + + return NULL; } - if (BINARY_CLASS_P (expr) || COMPARISON_CLASS_P (expr)) + + if (get_gimple_rhs_class (code) == GIMPLE_BINARY_RHS) { - tree op0, op1, res; - op0 = expr_expected_value (TREE_OPERAND (expr, 0), visited); + tree res; + op0 = expr_expected_value (op0, visited); if (!op0) return NULL; - op1 = expr_expected_value (TREE_OPERAND (expr, 1), visited); + op1 = expr_expected_value (op1, visited); if (!op1) return NULL; - res = fold_build2 (TREE_CODE (expr), TREE_TYPE (expr), op0, op1); + res = fold_build2 (code, type, op0, op1); if (TREE_CONSTANT (res)) return res; return NULL; } - if (UNARY_CLASS_P (expr)) + if (get_gimple_rhs_class (code) == GIMPLE_UNARY_RHS) { - tree op0, res; - op0 = expr_expected_value (TREE_OPERAND (expr, 0), visited); + tree res; + op0 = expr_expected_value (op0, visited); if (!op0) return NULL; - res = fold_build1 (TREE_CODE (expr), TREE_TYPE (expr), op0); + res = fold_build1 (code, type, op0); if (TREE_CONSTANT (res)) return res; return NULL; } return NULL; } + +/* Return constant EXPR will likely have at execution time, NULL if unknown. + The function is used by builtin_expect branch predictor so the evidence + must come from this construct and additional possible constant folding. + + We may want to implement more involved value guess (such as value range + propagation based prediction), but such tricks shall go to new + implementation. */ + +static tree +expr_expected_value (tree expr, bitmap visited) +{ + enum tree_code code; + tree op0, op1; + + if (TREE_CONSTANT (expr)) + return expr; + + extract_ops_from_tree (expr, &code, &op0, &op1); + return expr_expected_value_1 (TREE_TYPE (expr), + op0, code, op1, visited); +} + -/* Get rid of all builtin_expect calls we no longer need. */ -static void -strip_builtin_expect (void) +/* Get rid of all builtin_expect calls and GIMPLE_PREDICT statements + we no longer need. */ +static unsigned int +strip_predict_hints (void) { basic_block bb; + gimple ass_stmt; + tree var; + FOR_EACH_BB (bb) { - block_stmt_iterator bi; - for (bi = bsi_start (bb); !bsi_end_p (bi); bsi_next (&bi)) + gimple_stmt_iterator bi; + for (bi = gsi_start_bb (bb); !gsi_end_p (bi);) { - tree stmt = bsi_stmt (bi); - tree fndecl; - tree call; - - if (TREE_CODE (stmt) == GIMPLE_MODIFY_STMT - && (call = GIMPLE_STMT_OPERAND (stmt, 1)) - && TREE_CODE (call) == CALL_EXPR - && (fndecl = get_callee_fndecl (call)) - && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL - && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_EXPECT - && call_expr_nargs (call) == 2) + gimple stmt = gsi_stmt (bi); + + if (gimple_code (stmt) == GIMPLE_PREDICT) { - GIMPLE_STMT_OPERAND (stmt, 1) = CALL_EXPR_ARG (call, 0); - update_stmt (stmt); + gsi_remove (&bi, true); + continue; } + else if (gimple_code (stmt) == GIMPLE_CALL) + { + tree fndecl = gimple_call_fndecl (stmt); + + if (fndecl + && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL + && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_EXPECT + && gimple_call_num_args (stmt) == 2) + { + var = gimple_call_lhs (stmt); + ass_stmt = gimple_build_assign (var, gimple_call_arg (stmt, 0)); + + gsi_replace (&bi, ass_stmt, true); + } + } + gsi_next (&bi); } } + return 0; } /* Predict using opcode of the last statement in basic block. */ static void tree_predict_by_opcode (basic_block bb) { - tree stmt = last_stmt (bb); + gimple stmt = last_stmt (bb); edge then_edge; - tree cond; - tree op0; + tree op0, op1; tree type; tree val; + enum tree_code cmp; bitmap visited; edge_iterator ei; - if (!stmt || TREE_CODE (stmt) != COND_EXPR) + if (!stmt || gimple_code (stmt) != GIMPLE_COND) return; FOR_EACH_EDGE (then_edge, ei, bb->succs) if (then_edge->flags & EDGE_TRUE_VALUE) break; - cond = TREE_OPERAND (stmt, 0); - if (!COMPARISON_CLASS_P (cond)) - return; - op0 = TREE_OPERAND (cond, 0); + op0 = gimple_cond_lhs (stmt); + op1 = gimple_cond_rhs (stmt); + cmp = gimple_cond_code (stmt); type = TREE_TYPE (op0); visited = BITMAP_ALLOC (NULL); - val = expr_expected_value (cond, visited); + val = expr_expected_value_1 (boolean_type_node, op0, cmp, op1, visited); BITMAP_FREE (visited); if (val) { @@ -1050,9 +1343,9 @@ tree_predict_by_opcode (basic_block bb) Similarly, a comparison ptr1 == ptr2 is predicted as false. */ if (POINTER_TYPE_P (type)) { - if (TREE_CODE (cond) == EQ_EXPR) + if (cmp == EQ_EXPR) predict_edge_def (then_edge, PRED_TREE_POINTER, NOT_TAKEN); - else if (TREE_CODE (cond) == NE_EXPR) + else if (cmp == NE_EXPR) predict_edge_def (then_edge, PRED_TREE_POINTER, TAKEN); } else @@ -1061,7 +1354,7 @@ tree_predict_by_opcode (basic_block bb) EQ tests are usually false and NE tests are usually true. Also, most quantities are positive, so we can make the appropriate guesses about signed comparisons against zero. */ - switch (TREE_CODE (cond)) + switch (cmp) { case EQ_EXPR: case UNEQ_EXPR: @@ -1072,8 +1365,7 @@ tree_predict_by_opcode (basic_block bb) ; /* Comparisons with 0 are often used for booleans and there is nothing useful to predict about them. */ - else if (integer_zerop (op0) - || integer_zerop (TREE_OPERAND (cond, 1))) + else if (integer_zerop (op0) || integer_zerop (op1)) ; else predict_edge_def (then_edge, PRED_TREE_OPCODE_NONEQUAL, NOT_TAKEN); @@ -1089,7 +1381,7 @@ tree_predict_by_opcode (basic_block bb) /* Comparisons with 0 are often used for booleans and there is nothing useful to predict about them. */ else if (integer_zerop (op0) - || integer_zerop (TREE_OPERAND (cond, 1))) + || integer_zerop (op1)) ; else predict_edge_def (then_edge, PRED_TREE_OPCODE_NONEQUAL, TAKEN); @@ -1105,23 +1397,23 @@ tree_predict_by_opcode (basic_block bb) case LE_EXPR: case LT_EXPR: - if (integer_zerop (TREE_OPERAND (cond, 1)) - || integer_onep (TREE_OPERAND (cond, 1)) - || integer_all_onesp (TREE_OPERAND (cond, 1)) - || real_zerop (TREE_OPERAND (cond, 1)) - || real_onep (TREE_OPERAND (cond, 1)) - || real_minus_onep (TREE_OPERAND (cond, 1))) + if (integer_zerop (op1) + || integer_onep (op1) + || integer_all_onesp (op1) + || real_zerop (op1) + || real_onep (op1) + || real_minus_onep (op1)) predict_edge_def (then_edge, PRED_TREE_OPCODE_POSITIVE, NOT_TAKEN); break; case GE_EXPR: case GT_EXPR: - if (integer_zerop (TREE_OPERAND (cond, 1)) - || integer_onep (TREE_OPERAND (cond, 1)) - || integer_all_onesp (TREE_OPERAND (cond, 1)) - || real_zerop (TREE_OPERAND (cond, 1)) - || real_onep (TREE_OPERAND (cond, 1)) - || real_minus_onep (TREE_OPERAND (cond, 1))) + if (integer_zerop (op1) + || integer_onep (op1) + || integer_all_onesp (op1) + || real_zerop (op1) + || real_onep (op1) + || real_minus_onep (op1)) predict_edge_def (then_edge, PRED_TREE_OPCODE_POSITIVE, TAKEN); break; @@ -1131,6 +1423,7 @@ tree_predict_by_opcode (basic_block bb) } /* Try to guess whether the value of return means error code. */ + static enum br_predictor return_prediction (tree val, enum prediction *prediction) { @@ -1173,12 +1466,12 @@ return_prediction (tree val, enum prediction *prediction) /* Find the basic block with return expression and look up for possible return value trying to apply RETURN_PREDICTION heuristics. */ static void -apply_return_prediction (int *heads) +apply_return_prediction (void) { - tree return_stmt = NULL; + gimple return_stmt = NULL; tree return_val; edge e; - tree phi; + gimple phi; int phi_num_args, i; enum br_predictor pred; enum prediction direction; @@ -1187,26 +1480,21 @@ apply_return_prediction (int *heads) FOR_EACH_EDGE (e, ei, EXIT_BLOCK_PTR->preds) { return_stmt = last_stmt (e->src); - if (TREE_CODE (return_stmt) == RETURN_EXPR) + if (return_stmt + && gimple_code (return_stmt) == GIMPLE_RETURN) break; } if (!e) return; - return_val = TREE_OPERAND (return_stmt, 0); + return_val = gimple_return_retval (return_stmt); if (!return_val) return; - if (TREE_CODE (return_val) == GIMPLE_MODIFY_STMT) - return_val = GIMPLE_STMT_OPERAND (return_val, 1); if (TREE_CODE (return_val) != SSA_NAME || !SSA_NAME_DEF_STMT (return_val) - || TREE_CODE (SSA_NAME_DEF_STMT (return_val)) != PHI_NODE) + || gimple_code (SSA_NAME_DEF_STMT (return_val)) != GIMPLE_PHI) return; - for (phi = SSA_NAME_DEF_STMT (return_val); phi; phi = PHI_CHAIN (phi)) - if (PHI_RESULT (phi) == return_val) - break; - if (!phi) - return; - phi_num_args = PHI_NUM_ARGS (phi); + phi = SSA_NAME_DEF_STMT (return_val); + phi_num_args = gimple_phi_num_args (phi); pred = return_prediction (PHI_ARG_DEF (phi, 0), &direction); /* Avoid the degenerate case where all return values form the function @@ -1220,7 +1508,7 @@ apply_return_prediction (int *heads) { pred = return_prediction (PHI_ARG_DEF (phi, i), &direction); if (pred != PRED_NO_PREDICTION) - predict_paths_leading_to (PHI_ARG_EDGE (phi, i)->src, heads, pred, + predict_paths_leading_to (gimple_phi_arg_edge (phi, i)->src, pred, direction); } } @@ -1233,50 +1521,54 @@ static void tree_bb_level_predictions (void) { basic_block bb; - int *heads; - - heads = XCNEWVEC (int, last_basic_block); - heads[ENTRY_BLOCK_PTR->next_bb->index] = last_basic_block; - apply_return_prediction (heads); + apply_return_prediction (); FOR_EACH_BB (bb) { - block_stmt_iterator bsi = bsi_last (bb); + gimple_stmt_iterator gsi; - for (bsi = bsi_start (bb); !bsi_end_p (bsi); bsi_next (&bsi)) + for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi)) { - tree stmt = bsi_stmt (bsi); + gimple stmt = gsi_stmt (gsi); tree decl; - switch (TREE_CODE (stmt)) + + if (is_gimple_call (stmt)) { - case GIMPLE_MODIFY_STMT: - if (TREE_CODE (GIMPLE_STMT_OPERAND (stmt, 1)) == CALL_EXPR) - { - stmt = GIMPLE_STMT_OPERAND (stmt, 1); - goto call_expr; - } - break; - case CALL_EXPR: -call_expr:; - if (call_expr_flags (stmt) & ECF_NORETURN) - predict_paths_leading_to (bb, heads, PRED_NORETURN, - NOT_TAKEN); - decl = get_callee_fndecl (stmt); - if (decl - && lookup_attribute ("cold", - DECL_ATTRIBUTES (decl))) - predict_paths_leading_to (bb, heads, PRED_COLD_FUNCTION, - NOT_TAKEN); - break; - default: - break; + if (gimple_call_flags (stmt) & ECF_NORETURN) + predict_paths_leading_to (bb, PRED_NORETURN, + NOT_TAKEN); + decl = gimple_call_fndecl (stmt); + if (decl + && lookup_attribute ("cold", + DECL_ATTRIBUTES (decl))) + predict_paths_leading_to (bb, PRED_COLD_FUNCTION, + NOT_TAKEN); + } + else if (gimple_code (stmt) == GIMPLE_PREDICT) + { + predict_paths_leading_to (bb, gimple_predict_predictor (stmt), + gimple_predict_outcome (stmt)); + /* Keep GIMPLE_PREDICT around so early inlining will propagate + hints to callers. */ } } } +} + +#ifdef ENABLE_CHECKING - free (heads); +/* Callback for pointer_map_traverse, asserts that the pointer map is + empty. */ + +static bool +assert_is_empty (const void *key ATTRIBUTE_UNUSED, void **value, + void *data ATTRIBUTE_UNUSED) +{ + gcc_assert (!*value); + return false; } +#endif /* Predict branch probabilities and estimate profile of the tree CFG. */ static unsigned int @@ -1285,25 +1577,29 @@ tree_estimate_probability (void) basic_block bb; loop_optimizer_init (0); - if (current_loops && dump_file && (dump_flags & TDF_DETAILS)) + if (dump_file && (dump_flags & TDF_DETAILS)) flow_loops_dump (dump_file, NULL, 0); add_noreturn_fake_exit_edges (); connect_infinite_loops_to_exit (); - calculate_dominance_info (CDI_DOMINATORS); + /* We use loop_niter_by_eval, which requires that the loops have + preheaders. */ + create_preheaders (CP_SIMPLE_PREHEADERS); calculate_dominance_info (CDI_POST_DOMINATORS); + bb_predictions = pointer_map_create (); tree_bb_level_predictions (); mark_irreducible_loops (); record_loop_exits (); - if (current_loops) + if (number_of_loops () > 1) predict_loops (); FOR_EACH_BB (bb) { edge e; edge_iterator ei; + gimple last; FOR_EACH_EDGE (e, ei, bb->succs) { @@ -1326,7 +1622,8 @@ tree_estimate_probability (void) && e->dest != EXIT_BLOCK_PTR && single_succ_p (e->dest) && single_succ_edge (e->dest)->dest == EXIT_BLOCK_PTR - && TREE_CODE (last_stmt (e->dest)) == RETURN_EXPR) + && (last = last_stmt (e->dest)) != NULL + && gimple_code (last) == GIMPLE_RETURN) { edge e1; edge_iterator ei1; @@ -1352,23 +1649,20 @@ tree_estimate_probability (void) && dominated_by_p (CDI_DOMINATORS, e->dest, e->src) && !dominated_by_p (CDI_POST_DOMINATORS, e->src, e->dest)) { - block_stmt_iterator bi; + gimple_stmt_iterator bi; /* The call heuristic claims that a guarded function call is improbable. This is because such calls are often used to signal exceptional situations such as printing error messages. */ - for (bi = bsi_start (e->dest); !bsi_end_p (bi); - bsi_next (&bi)) + for (bi = gsi_start_bb (e->dest); !gsi_end_p (bi); + gsi_next (&bi)) { - tree stmt = bsi_stmt (bi); - if ((TREE_CODE (stmt) == CALL_EXPR - || (TREE_CODE (stmt) == GIMPLE_MODIFY_STMT - && TREE_CODE (GIMPLE_STMT_OPERAND (stmt, 1)) - == CALL_EXPR)) + gimple stmt = gsi_stmt (bi); + if (is_gimple_call (stmt) /* Constant and pure calls are hardly used to signalize something exceptional. */ - && TREE_SIDE_EFFECTS (stmt)) + && gimple_has_side_effects (stmt)) { predict_edge_def (e, PRED_CALL, NOT_TAKEN); break; @@ -1381,70 +1675,58 @@ tree_estimate_probability (void) FOR_EACH_BB (bb) combine_predictions_for_bb (bb); - strip_builtin_expect (); +#ifdef ENABLE_CHECKING + pointer_map_traverse (bb_predictions, assert_is_empty, NULL); +#endif + pointer_map_destroy (bb_predictions); + bb_predictions = NULL; + estimate_bb_frequencies (); free_dominance_info (CDI_POST_DOMINATORS); remove_fake_exit_edges (); loop_optimizer_finalize (); if (dump_file && (dump_flags & TDF_DETAILS)) - dump_tree_cfg (dump_file, dump_flags); + gimple_dump_cfg (dump_file, dump_flags); if (profile_status == PROFILE_ABSENT) profile_status = PROFILE_GUESSED; return 0; } -/* Sets branch probabilities according to PREDiction and - FLAGS. HEADS[bb->index] should be index of basic block in that we - need to alter branch predictions (i.e. the first of our dominators - such that we do not post-dominate it) (but we fill this information - on demand, so -1 may be there in case this was not needed yet). */ +/* Predict edges to successors of CUR whose sources are not postdominated by + BB by PRED and recurse to all postdominators. */ static void -predict_paths_leading_to (basic_block bb, int *heads, enum br_predictor pred, - enum prediction taken) +predict_paths_for_bb (basic_block cur, basic_block bb, + enum br_predictor pred, + enum prediction taken) { edge e; edge_iterator ei; - int y; + basic_block son; - if (heads[bb->index] == ENTRY_BLOCK) + /* We are looking for all edges forming edge cut induced by + set of all blocks postdominated by BB. */ + FOR_EACH_EDGE (e, ei, cur->preds) + if (e->src->index >= NUM_FIXED_BLOCKS + && !dominated_by_p (CDI_POST_DOMINATORS, e->src, bb)) { - /* This is first time we need this field in heads array; so - find first dominator that we do not post-dominate (we are - using already known members of heads array). */ - basic_block ai = bb; - basic_block next_ai = get_immediate_dominator (CDI_DOMINATORS, bb); - int head; - - while (heads[next_ai->index] == ENTRY_BLOCK) - { - if (!dominated_by_p (CDI_POST_DOMINATORS, next_ai, bb)) - break; - heads[next_ai->index] = ai->index; - ai = next_ai; - next_ai = get_immediate_dominator (CDI_DOMINATORS, next_ai); - } - if (!dominated_by_p (CDI_POST_DOMINATORS, next_ai, bb)) - head = next_ai->index; - else - head = heads[next_ai->index]; - while (next_ai != bb) - { - next_ai = ai; - ai = BASIC_BLOCK (heads[ai->index]); - heads[next_ai->index] = head; - } + gcc_assert (bb == cur || dominated_by_p (CDI_POST_DOMINATORS, cur, bb)); + predict_edge_def (e, pred, taken); } - y = heads[bb->index]; + for (son = first_dom_son (CDI_POST_DOMINATORS, cur); + son; + son = next_dom_son (CDI_POST_DOMINATORS, son)) + predict_paths_for_bb (son, bb, pred, taken); +} - /* Now find the edge that leads to our branch and aply the prediction. */ +/* Sets branch probabilities according to PREDiction and + FLAGS. */ - if (y == last_basic_block) - return; - FOR_EACH_EDGE (e, ei, BASIC_BLOCK (y)->succs) - if (e->dest->index >= NUM_FIXED_BLOCKS - && dominated_by_p (CDI_POST_DOMINATORS, e->dest, bb)) - predict_edge_def (e, pred, taken); +static void +predict_paths_leading_to (basic_block bb, enum br_predictor pred, + enum prediction taken) +{ + predict_paths_for_bb (bb, bb, pred, taken); } /* This is used to carry information about basic blocks. It is @@ -1654,7 +1936,7 @@ estimate_loops (void) basic_block bb; /* Start by estimating the frequencies in the loops. */ - if (current_loops) + if (number_of_loops () > 1) estimate_loops_at_level (current_loops->tree_root->inner); /* Now propagate the frequencies through all the blocks. */ @@ -1734,7 +2016,7 @@ estimate_bb_frequencies (void) basic_block bb; sreal freq_max; - if (!flag_branch_probabilities || !counts_to_freqs ()) + if (cfun->function_frequency != PROFILE_READ || !counts_to_freqs ()) { static int real_values_initialized = 0; @@ -1861,8 +2143,26 @@ gate_estimate_probability (void) return flag_guess_branch_prob; } -struct tree_opt_pass pass_profile = +/* Build PREDICT_EXPR. */ +tree +build_predict_expr (enum br_predictor predictor, enum prediction taken) { + tree t = build1 (PREDICT_EXPR, void_type_node, + build_int_cst (NULL, predictor)); + PREDICT_EXPR_OUTCOME (t) = taken; + return t; +} + +const char * +predictor_name (enum br_predictor predictor) +{ + return predictor_info[predictor].name; +} + +struct gimple_opt_pass pass_profile = +{ + { + GIMPLE_PASS, "profile", /* name */ gate_estimate_probability, /* gate */ tree_estimate_probability, /* execute */ @@ -1874,6 +2174,25 @@ struct tree_opt_pass pass_profile = 0, /* properties_provided */ 0, /* properties_destroyed */ 0, /* todo_flags_start */ - TODO_ggc_collect | TODO_verify_ssa, /* todo_flags_finish */ - 0 /* letter */ + TODO_ggc_collect | TODO_verify_ssa /* todo_flags_finish */ + } +}; + +struct gimple_opt_pass pass_strip_predict_hints = +{ + { + GIMPLE_PASS, + NULL, /* name */ + NULL, /* gate */ + strip_predict_hints, /* execute */ + NULL, /* sub */ + NULL, /* next */ + 0, /* static_pass_number */ + TV_BRANCH_PROB, /* tv_id */ + PROP_cfg, /* properties_required */ + 0, /* properties_provided */ + 0, /* properties_destroyed */ + 0, /* todo_flags_start */ + TODO_ggc_collect | TODO_verify_ssa /* todo_flags_finish */ + } };