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predict.c (combine_predictions_for_bb): Add dry_run parmaeter.

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* predict.c (combine_predictions_for_bb): Add dry_run parmaeter.
	(tree_estimate_probability): Likewise.
	(pass_profile::execute): Update.
	(report_predictor_hitrates): New function.
	* profile.c (compute_branch_probabilities): Use it.
	* predict.h (report_predictor_hitrates): Declare.

From-SVN: r235082
This commit is contained in:
Jan Hubicka 2016-04-17 18:08:27 +02:00 committed by Jan Hubicka
parent 69a4e898c8
commit 460545e85a
4 changed files with 51 additions and 9 deletions
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9
gcc/ChangeLog
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@ -1,3 +1,12 @@
2016-04-17 Jan Hubicka <jh@suse.cz>
* predict.c (combine_predictions_for_bb): Add dry_run parmaeter.
(tree_estimate_probability): Likewise.
(pass_profile::execute): Update.
(report_predictor_hitrates): New function.
* profile.c (compute_branch_probabilities): Use it.
* predict.h (report_predictor_hitrates): Declare.
2016-04-17 Jan Hubicka <jh@suse.cz>
PR ipa/70018

48
gcc/predict.c
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@ -842,10 +842,11 @@ combine_predictions_for_insn (rtx_insn *insn, basic_block bb)
}
/* Combine predictions into single probability and store them into CFG.
Remove now useless prediction entries. */
Remove now useless prediction entries.
If DRY_RUN is set, only produce dumps and do not modify profile. */
static void
combine_predictions_for_bb (basic_block bb)
combine_predictions_for_bb (basic_block bb, bool dry_run)
{
int best_probability = PROB_EVEN;
enum br_predictor best_predictor = END_PREDICTORS;
@ -876,7 +877,7 @@ combine_predictions_for_bb (basic_block bb)
this later. */
if (nedges != 2)
{
if (!bb->count)
if (!bb->count && !dry_run)
set_even_probabilities (bb);
clear_bb_predictions (bb);
if (dump_file)
@ -982,7 +983,7 @@ combine_predictions_for_bb (basic_block bb)
}
clear_bb_predictions (bb);
if (!bb->count)
if (!bb->count && !dry_run)
{
first->probability = combined_probability;
second->probability = REG_BR_PROB_BASE - combined_probability;
@ -2327,10 +2328,11 @@ tree_estimate_probability_bb (basic_block bb)
/* Predict branch probabilities and estimate profile of the tree CFG.
This function can be called from the loop optimizers to recompute
the profile information. */
the profile information.
If DRY_RUN is set, do not modify CFG and only produce dump files. */
void
tree_estimate_probability (void)
tree_estimate_probability (bool dry_run)
{
basic_block bb;
@ -2352,7 +2354,7 @@ tree_estimate_probability (void)
tree_estimate_probability_bb (bb);
FOR_EACH_BB_FN (bb, cfun)
combine_predictions_for_bb (bb);
combine_predictions_for_bb (bb, dry_run);
if (flag_checking)
bb_predictions->traverse<void *, assert_is_empty> (NULL);
@ -2360,7 +2362,8 @@ tree_estimate_probability (void)
delete bb_predictions;
bb_predictions = NULL;
estimate_bb_frequencies (false);
if (!dry_run)
estimate_bb_frequencies (false);
free_dominance_info (CDI_POST_DOMINATORS);
remove_fake_exit_edges ();
}
@ -3040,7 +3043,7 @@ pass_profile::execute (function *fun)
if (nb_loops > 1)
scev_initialize ();
tree_estimate_probability ();
tree_estimate_probability (false);
if (nb_loops > 1)
scev_finalize ();
@ -3191,3 +3194,30 @@ rebuild_frequencies (void)
gcc_unreachable ();
timevar_pop (TV_REBUILD_FREQUENCIES);
}
/* Perform a dry run of the branch prediction pass and report comparsion of
the predicted and real profile into the dump file. */
void
report_predictor_hitrates (void)
{
unsigned nb_loops;
loop_optimizer_init (LOOPS_NORMAL);
if (dump_file && (dump_flags & TDF_DETAILS))
flow_loops_dump (dump_file, NULL, 0);
mark_irreducible_loops ();
nb_loops = number_of_loops (cfun);
if (nb_loops > 1)
scev_initialize ();
tree_estimate_probability (true);
if (nb_loops > 1)
scev_finalize ();
loop_optimizer_finalize ();
}

1
gcc/predict.h
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@ -90,5 +90,6 @@ extern void compute_function_frequency (void);
extern tree build_predict_expr (enum br_predictor, enum prediction);
extern const char *predictor_name (enum br_predictor);
extern void rebuild_frequencies (void);
extern void report_predictor_hitrates (void);
#endif /* GCC_PREDICT_H */

2
gcc/profile.c
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@ -845,6 +845,8 @@ compute_branch_probabilities (unsigned cfg_checksum, unsigned lineno_checksum)
fputc ('\n', dump_file);
fputc ('\n', dump_file);
}
if (dump_file && (dump_flags & TDF_DETAILS))
report_predictor_hitrates ();
free_aux_for_blocks ();
}