diff options
Diffstat (limited to 'gcc/predict.c')
| -rw-r--r-- | gcc/predict.c | 151 |
1 files changed, 112 insertions, 39 deletions
diff --git a/gcc/predict.c b/gcc/predict.c index 9a15c87dac9..affed79ae9d 100644 --- a/gcc/predict.c +++ b/gcc/predict.c @@ -232,8 +232,38 @@ bool probably_never_executed_bb_p (struct function *fun, const_basic_block bb) { gcc_checking_assert (fun); + if (profile_status_for_function (fun) == PROFILE_READ) + { + if ((bb->count * 4 + profile_info->runs / 2) / profile_info->runs > 0) + return false; + if (!bb->frequency) + return true; + if (!ENTRY_BLOCK_PTR->frequency) + return false; + if (ENTRY_BLOCK_PTR->count && ENTRY_BLOCK_PTR->count < REG_BR_PROB_BASE) + { + return (RDIV (bb->frequency * ENTRY_BLOCK_PTR->count, + ENTRY_BLOCK_PTR->frequency) + < REG_BR_PROB_BASE / 4); + } + return true; + } + if ((!profile_info || !flag_branch_probabilities) + && (cgraph_get_node (fun->decl)->frequency + == NODE_FREQUENCY_UNLIKELY_EXECUTED)) + return true; + return false; +} + + +/* Return true in case edge E is probably never executed. */ + +bool +probably_never_executed_edge_p (struct function *fun, edge e) +{ + gcc_checking_assert (fun); if (profile_info && flag_branch_probabilities) - return ((bb->count + profile_info->runs / 2) / profile_info->runs) == 0; + return ((e->count + profile_info->runs / 2) / profile_info->runs) == 0; if ((!profile_info || !flag_branch_probabilities) && (cgraph_get_node (fun->decl)->frequency == NODE_FREQUENCY_UNLIKELY_EXECUTED)) @@ -2841,13 +2871,14 @@ compute_function_frequency (void) { basic_block bb; struct cgraph_node *node = cgraph_get_node (current_function_decl); + if (DECL_STATIC_CONSTRUCTOR (current_function_decl) || MAIN_NAME_P (DECL_NAME (current_function_decl))) node->only_called_at_startup = true; if (DECL_STATIC_DESTRUCTOR (current_function_decl)) node->only_called_at_exit = true; - if (!profile_info || !flag_branch_probabilities) + if (profile_status != PROFILE_READ) { int flags = flags_from_decl_or_type (current_function_decl); if (lookup_attribute ("cold", DECL_ATTRIBUTES (current_function_decl)) @@ -2865,7 +2896,13 @@ compute_function_frequency (void) node->frequency = NODE_FREQUENCY_EXECUTED_ONCE; return; } - node->frequency = NODE_FREQUENCY_UNLIKELY_EXECUTED; + + /* Only first time try to drop function into unlikely executed. + After inlining the roundoff errors may confuse us. + Ipa-profile pass will drop functions only called from unlikely + functions to unlikely and that is most of what we care about. */ + if (!cfun->after_inlining) + node->frequency = NODE_FREQUENCY_UNLIKELY_EXECUTED; FOR_EACH_BB (bb) { if (maybe_hot_bb_p (cfun, bb)) @@ -2900,46 +2937,82 @@ predictor_name (enum br_predictor predictor) return predictor_info[predictor].name; } -struct gimple_opt_pass pass_profile = -{ - { - GIMPLE_PASS, - "profile_estimate", /* name */ - OPTGROUP_NONE, /* optinfo_flags */ - gate_estimate_probability, /* gate */ - tree_estimate_probability_driver, /* 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_verify_ssa /* todo_flags_finish */ - } +namespace { + +const pass_data pass_data_profile = +{ + GIMPLE_PASS, /* type */ + "profile_estimate", /* name */ + OPTGROUP_NONE, /* optinfo_flags */ + true, /* has_gate */ + true, /* has_execute */ + TV_BRANCH_PROB, /* tv_id */ + PROP_cfg, /* properties_required */ + 0, /* properties_provided */ + 0, /* properties_destroyed */ + 0, /* todo_flags_start */ + TODO_verify_ssa, /* todo_flags_finish */ }; -struct gimple_opt_pass pass_strip_predict_hints = -{ - { - GIMPLE_PASS, - "*strip_predict_hints", /* name */ - OPTGROUP_NONE, /* optinfo_flags */ - 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_verify_ssa /* todo_flags_finish */ - } +class pass_profile : public gimple_opt_pass +{ +public: + pass_profile(gcc::context *ctxt) + : gimple_opt_pass(pass_data_profile, ctxt) + {} + + /* opt_pass methods: */ + bool gate () { return gate_estimate_probability (); } + unsigned int execute () { return tree_estimate_probability_driver (); } + +}; // class pass_profile + +} // anon namespace + +gimple_opt_pass * +make_pass_profile (gcc::context *ctxt) +{ + return new pass_profile (ctxt); +} + +namespace { + +const pass_data pass_data_strip_predict_hints = +{ + GIMPLE_PASS, /* type */ + "*strip_predict_hints", /* name */ + OPTGROUP_NONE, /* optinfo_flags */ + false, /* has_gate */ + true, /* has_execute */ + TV_BRANCH_PROB, /* tv_id */ + PROP_cfg, /* properties_required */ + 0, /* properties_provided */ + 0, /* properties_destroyed */ + 0, /* todo_flags_start */ + TODO_verify_ssa, /* todo_flags_finish */ }; +class pass_strip_predict_hints : public gimple_opt_pass +{ +public: + pass_strip_predict_hints(gcc::context *ctxt) + : gimple_opt_pass(pass_data_strip_predict_hints, ctxt) + {} + + /* opt_pass methods: */ + opt_pass * clone () { return new pass_strip_predict_hints (ctxt_); } + unsigned int execute () { return strip_predict_hints (); } + +}; // class pass_strip_predict_hints + +} // anon namespace + +gimple_opt_pass * +make_pass_strip_predict_hints (gcc::context *ctxt) +{ + return new pass_strip_predict_hints (ctxt); +} + /* Rebuild function frequencies. Passes are in general expected to maintain profile by hand, however in some cases this is not possible: for example when inlining several functions with loops freuqencies might run |