diff options
author | Martin Liska <mliska@suse.cz> | 2016-06-09 13:37:41 +0200 |
---|---|---|
committer | Martin Liska <marxin@gcc.gnu.org> | 2016-06-09 11:37:41 +0000 |
commit | e49efc14a17f32b2801dfa481081a0cabc083fe7 (patch) | |
tree | e3753f419888a5394694e152cd1c15fd95083483 /gcc | |
parent | 36d579866680fd2b45800b072527a9cce93235d0 (diff) | |
download | gcc-e49efc14a17f32b2801dfa481081a0cabc083fe7.zip gcc-e49efc14a17f32b2801dfa481081a0cabc083fe7.tar.gz gcc-e49efc14a17f32b2801dfa481081a0cabc083fe7.tar.bz2 |
Add edge predictions pruning
* analyze_brprob.py: Cover new dump output format.
* predict.c (dump_prediction): Add new argument.
(enum predictor_reason): New enum.
(struct predictor_hash): New struct.
(predictor_hash::hash): New function.
(predictor_hash::equal): Likewise.
(not_removed_prediction_p): New function.
(prune_predictions_for_bb): Likewise.
(combine_predictions_for_bb): Prune predictions.
* g++.dg/predict-loop-exit-1.C: Scan for a new dump format.
* g++.dg/predict-loop-exit-2.C: Likewise.
* g++.dg/predict-loop-exit-3.C: Likewise.
* gcc.dg/predict-1.c: Likewise.
* gcc.dg/predict-2.c: Likewise.
* gcc.dg/predict-3.c: Likewise.
* gcc.dg/predict-4.c: Likewise.
* gcc.dg/predict-5.c: Likewise.
* gcc.dg/predict-6.c: Likewise.
* gcc.dg/predict-7.c: Likewise.
From-SVN: r237255
Diffstat (limited to 'gcc')
-rw-r--r-- | gcc/ChangeLog | 11 | ||||
-rw-r--r-- | gcc/predict.c | 184 | ||||
-rw-r--r-- | gcc/testsuite/ChangeLog | 13 | ||||
-rw-r--r-- | gcc/testsuite/g++.dg/predict-loop-exit-1.C | 4 | ||||
-rw-r--r-- | gcc/testsuite/g++.dg/predict-loop-exit-2.C | 4 | ||||
-rw-r--r-- | gcc/testsuite/g++.dg/predict-loop-exit-3.C | 4 | ||||
-rw-r--r-- | gcc/testsuite/gcc.dg/predict-1.c | 2 | ||||
-rw-r--r-- | gcc/testsuite/gcc.dg/predict-2.c | 2 | ||||
-rw-r--r-- | gcc/testsuite/gcc.dg/predict-3.c | 2 | ||||
-rw-r--r-- | gcc/testsuite/gcc.dg/predict-4.c | 2 | ||||
-rw-r--r-- | gcc/testsuite/gcc.dg/predict-5.c | 2 | ||||
-rw-r--r-- | gcc/testsuite/gcc.dg/predict-6.c | 2 | ||||
-rw-r--r-- | gcc/testsuite/gcc.dg/predict-7.c | 2 |
13 files changed, 201 insertions, 33 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 134f224..9c7a0b4 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -6,6 +6,17 @@ 2016-06-09 Martin Liska <mliska@suse.cz> + * predict.c (dump_prediction): Add new argument. + (enum predictor_reason): New enum. + (struct predictor_hash): New struct. + (predictor_hash::hash): New function. + (predictor_hash::equal): Likewise. + (not_removed_prediction_p): New function. + (prune_predictions_for_bb): Likewise. + (combine_predictions_for_bb): Prune predictions. + +2016-06-09 Martin Liska <mliska@suse.cz> + * predict.c (filter_predictions): New function. (remove_predictions_associated_with_edge): Use the filter function. diff --git a/gcc/predict.c b/gcc/predict.c index f00428f..0fa8c5b 100644 --- a/gcc/predict.c +++ b/gcc/predict.c @@ -55,13 +55,29 @@ along with GCC; see the file COPYING3. If not see #include "tree-ssa-loop.h" #include "tree-scalar-evolution.h" +/* Enum with reasons why a predictor is ignored. */ + +enum predictor_reason +{ + NONE, + IGNORED, + SINGLE_EDGE_DUPLICATE, + EDGE_PAIR_DUPLICATE +}; + +/* String messages for the aforementioned enum. */ + +static const char *reason_messages[] = {"", " (ignored)", + " (single edge duplicate)", " (edge pair duplicate)"}; + /* 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_almost_one, real_br_prob_base, real_inv_br_prob_base, real_one_half, real_bb_freq_max; static void combine_predictions_for_insn (rtx_insn *, basic_block); -static void dump_prediction (FILE *, enum br_predictor, int, basic_block, int); +static void dump_prediction (FILE *, enum br_predictor, int, basic_block, + enum predictor_reason, edge); static void predict_paths_leading_to (basic_block, enum br_predictor, enum prediction); static void predict_paths_leading_to_edge (edge, enum br_predictor, enum prediction); static bool can_predict_insn_p (const rtx_insn *); @@ -723,21 +739,31 @@ invert_br_probabilities (rtx insn) static void dump_prediction (FILE *file, enum br_predictor predictor, int probability, - basic_block bb, int used) + basic_block bb, enum predictor_reason reason = NONE, + edge ep_edge = NULL) { - edge e; + edge e = ep_edge; edge_iterator ei; if (!file) return; - FOR_EACH_EDGE (e, ei, bb->succs) - if (! (e->flags & EDGE_FALLTHRU)) - break; + if (e == NULL) + FOR_EACH_EDGE (e, ei, bb->succs) + if (! (e->flags & EDGE_FALLTHRU)) + break; + + char edge_info_str[128]; + if (ep_edge) + sprintf (edge_info_str, " of edge %d->%d", ep_edge->src->index, + ep_edge->dest->index); + else + edge_info_str[0] = '\0'; - fprintf (file, " %s heuristics%s: %.1f%%", + fprintf (file, " %s heuristics%s%s: %.1f%%", predictor_info[predictor].name, - used ? "" : " (ignored)", probability * 100.0 / REG_BR_PROB_BASE); + edge_info_str, reason_messages[reason], + probability * 100.0 / REG_BR_PROB_BASE); if (bb->count) { @@ -834,18 +860,18 @@ combine_predictions_for_insn (rtx_insn *insn, basic_block bb) if (!found) dump_prediction (dump_file, PRED_NO_PREDICTION, - combined_probability, bb, true); + combined_probability, bb); else { dump_prediction (dump_file, PRED_DS_THEORY, combined_probability, - bb, !first_match); + bb, !first_match ? NONE : IGNORED); dump_prediction (dump_file, PRED_FIRST_MATCH, best_probability, - bb, first_match); + bb, first_match ? NONE: IGNORED); } if (first_match) combined_probability = best_probability; - dump_prediction (dump_file, PRED_COMBINED, combined_probability, bb, true); + dump_prediction (dump_file, PRED_COMBINED, combined_probability, bb); while (*pnote) { @@ -856,7 +882,8 @@ combine_predictions_for_insn (rtx_insn *insn, basic_block bb) int probability = INTVAL (XEXP (XEXP (*pnote, 0), 1)); dump_prediction (dump_file, predictor, probability, bb, - !first_match || best_predictor == predictor); + (!first_match || best_predictor == predictor) + ? NONE : IGNORED); *pnote = XEXP (*pnote, 1); } else @@ -887,6 +914,121 @@ combine_predictions_for_insn (rtx_insn *insn, basic_block bb) single_succ_edge (bb)->probability = REG_BR_PROB_BASE; } +/* Edge prediction hash traits. */ + +struct predictor_hash: pointer_hash <edge_prediction> +{ + + static inline hashval_t hash (const edge_prediction *); + static inline bool equal (const edge_prediction *, const edge_prediction *); +}; + +/* Calculate hash value of an edge prediction P based on predictor and + normalized probability. */ + +inline hashval_t +predictor_hash::hash (const edge_prediction *p) +{ + inchash::hash hstate; + hstate.add_int (p->ep_predictor); + + int prob = p->ep_probability; + if (prob > REG_BR_PROB_BASE / 2) + prob = REG_BR_PROB_BASE - prob; + + hstate.add_int (prob); + + return hstate.end (); +} + +/* Return true whether edge predictions P1 and P2 use the same predictor and + have equal (or opposed probability). */ + +inline bool +predictor_hash::equal (const edge_prediction *p1, const edge_prediction *p2) +{ + return (p1->ep_predictor == p2->ep_predictor + && (p1->ep_probability == p2->ep_probability + || p1->ep_probability == REG_BR_PROB_BASE - p2->ep_probability)); +} + +struct predictor_hash_traits: predictor_hash, + typed_noop_remove <edge_prediction *> {}; + +/* Return true if edge prediction P is not in DATA hash set. */ + +static bool +not_removed_prediction_p (edge_prediction *p, void *data) +{ + hash_set<edge_prediction *> *remove = (hash_set<edge_prediction *> *) data; + return !remove->contains (p); +} + +/* Prune predictions for a basic block BB. Currently we do following + clean-up steps: + + 1) remove duplicate prediction that is guessed with the same probability + (different than 1/2) to both edge + 2) remove duplicates for a prediction that belongs with the same probability + to a single edge + + */ + +static void +prune_predictions_for_bb (basic_block bb) +{ + edge_prediction **preds = bb_predictions->get (bb); + + if (preds) + { + hash_table <predictor_hash_traits> s (13); + hash_set <edge_prediction *> remove; + + /* Step 1: identify predictors that should be removed. */ + for (edge_prediction *pred = *preds; pred; pred = pred->ep_next) + { + edge_prediction *existing = s.find (pred); + if (existing) + { + if (pred->ep_edge == existing->ep_edge + && pred->ep_probability == existing->ep_probability) + { + /* Remove a duplicate predictor. */ + dump_prediction (dump_file, pred->ep_predictor, + pred->ep_probability, bb, + SINGLE_EDGE_DUPLICATE, pred->ep_edge); + + remove.add (pred); + } + else if (pred->ep_edge != existing->ep_edge + && pred->ep_probability == existing->ep_probability + && pred->ep_probability != REG_BR_PROB_BASE / 2) + { + /* Remove both predictors as they predict the same + for both edges. */ + dump_prediction (dump_file, existing->ep_predictor, + pred->ep_probability, bb, + EDGE_PAIR_DUPLICATE, + existing->ep_edge); + dump_prediction (dump_file, pred->ep_predictor, + pred->ep_probability, bb, + EDGE_PAIR_DUPLICATE, + pred->ep_edge); + + remove.add (existing); + remove.add (pred); + } + } + + edge_prediction **slot2 = s.find_slot (pred, INSERT); + *slot2 = pred; + } + + /* Step 2: Remove predictors. */ + filter_predictions (preds, not_removed_prediction_p, &remove); + } +} + /* Combine predictions into single probability and store them into CFG. Remove now useless prediction entries. If DRY_RUN is set, only produce dumps and do not modify profile. */ @@ -935,7 +1077,10 @@ combine_predictions_for_bb (basic_block bb, bool dry_run) if (dump_file) fprintf (dump_file, "Predictions for bb %i\n", bb->index); + prune_predictions_for_bb (bb); + edge_prediction **preds = bb_predictions->get (bb); + if (preds) { /* We implement "first match" heuristics and use probability guessed @@ -1001,18 +1146,18 @@ combine_predictions_for_bb (basic_block bb, bool dry_run) first_match = true; if (!found) - dump_prediction (dump_file, PRED_NO_PREDICTION, combined_probability, bb, true); + dump_prediction (dump_file, PRED_NO_PREDICTION, combined_probability, bb); else { dump_prediction (dump_file, PRED_DS_THEORY, combined_probability, bb, - !first_match); + !first_match ? NONE : IGNORED); dump_prediction (dump_file, PRED_FIRST_MATCH, best_probability, bb, - first_match); + first_match ? NONE : IGNORED); } if (first_match) combined_probability = best_probability; - dump_prediction (dump_file, PRED_COMBINED, combined_probability, bb, true); + dump_prediction (dump_file, PRED_COMBINED, combined_probability, bb); if (preds) { @@ -1021,10 +1166,9 @@ combine_predictions_for_bb (basic_block bb, bool dry_run) enum br_predictor 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); + (!first_match || best_predictor == predictor) + ? NONE : IGNORED, pred->ep_edge); } } clear_bb_predictions (bb); diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 8ee01b7..155dc11 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,16 @@ +2016-06-09 Martin Liska <mliska@suse.cz> + + * g++.dg/predict-loop-exit-1.C: Scan for a new dump format. + * g++.dg/predict-loop-exit-2.C: Likewise. + * g++.dg/predict-loop-exit-3.C: Likewise. + * gcc.dg/predict-1.c: Likewise. + * gcc.dg/predict-2.c: Likewise. + * gcc.dg/predict-3.c: Likewise. + * gcc.dg/predict-4.c: Likewise. + * gcc.dg/predict-5.c: Likewise. + * gcc.dg/predict-6.c: Likewise. + * gcc.dg/predict-7.c: Likewise. + 2016-06-09 Richard Biener <rguenther@suse.de> PR tree-optimization/71462 diff --git a/gcc/testsuite/g++.dg/predict-loop-exit-1.C b/gcc/testsuite/g++.dg/predict-loop-exit-1.C index 357397f..88262eb 100644 --- a/gcc/testsuite/g++.dg/predict-loop-exit-1.C +++ b/gcc/testsuite/g++.dg/predict-loop-exit-1.C @@ -9,5 +9,5 @@ void test() { return; } -/* { dg-final { scan-tree-dump-times "extra loop exit heuristics:" 2 "profile_estimate"} } */ -/* { dg-final { scan-tree-dump-times "loop exit heuristics:" 3 "profile_estimate"} } */ +/* { dg-final { scan-tree-dump-times "extra loop exit heuristics of edge\[^:\]*:" 2 "profile_estimate"} } */ +/* { dg-final { scan-tree-dump-times "loop exit heuristics of edge\[^:\]*:" 3 "profile_estimate"} } */ diff --git a/gcc/testsuite/g++.dg/predict-loop-exit-2.C b/gcc/testsuite/g++.dg/predict-loop-exit-2.C index 172fab1..15e9866 100644 --- a/gcc/testsuite/g++.dg/predict-loop-exit-2.C +++ b/gcc/testsuite/g++.dg/predict-loop-exit-2.C @@ -9,5 +9,5 @@ void test() { return; } -/* { dg-final { scan-tree-dump-times "extra loop exit heuristics:" 1 "profile_estimate"} } */ -/* { dg-final { scan-tree-dump-times "loop exit heuristics:" 2 "profile_estimate"} } */ +/* { dg-final { scan-tree-dump-times "extra loop exit heuristics of edge\[^:\]*:" 1 "profile_estimate"} } */ +/* { dg-final { scan-tree-dump-times "loop exit heuristics of edge\[^:\]*:" 2 "profile_estimate"} } */ diff --git a/gcc/testsuite/g++.dg/predict-loop-exit-3.C b/gcc/testsuite/g++.dg/predict-loop-exit-3.C index e6ceec8..61af84b 100644 --- a/gcc/testsuite/g++.dg/predict-loop-exit-3.C +++ b/gcc/testsuite/g++.dg/predict-loop-exit-3.C @@ -9,5 +9,5 @@ void test() { return; } -/* { dg-final { scan-tree-dump-times "extra loop exit heuristics:" 2 "profile_estimate"} } */ -/* { dg-final { scan-tree-dump-times "loop exit heuristics:" 3 "profile_estimate"} } */ +/* { dg-final { scan-tree-dump-times "extra loop exit heuristics of edge\[^:\]*:" 2 "profile_estimate"} } */ +/* { dg-final { scan-tree-dump-times "loop exit heuristics of edge\[^:\]*:" 3 "profile_estimate"} } */ diff --git a/gcc/testsuite/gcc.dg/predict-1.c b/gcc/testsuite/gcc.dg/predict-1.c index 94f6b019..d0924f2 100644 --- a/gcc/testsuite/gcc.dg/predict-1.c +++ b/gcc/testsuite/gcc.dg/predict-1.c @@ -23,4 +23,4 @@ void foo (int bound) } } -/* { dg-final { scan-tree-dump-times "loop iv compare heuristics: 2.0%" 5 "profile_estimate"} } */ +/* { dg-final { scan-tree-dump-times "loop iv compare heuristics of edge\[^:\]*: 2.0%" 5 "profile_estimate"} } */ diff --git a/gcc/testsuite/gcc.dg/predict-2.c b/gcc/testsuite/gcc.dg/predict-2.c index f2fc49d..3011686 100644 --- a/gcc/testsuite/gcc.dg/predict-2.c +++ b/gcc/testsuite/gcc.dg/predict-2.c @@ -23,4 +23,4 @@ void foo (int base, int bound) } } -/* { dg-final { scan-tree-dump-not "loop iv compare heuristics" "profile_estimate"} } */ +/* { dg-final { scan-tree-dump-not "loop iv compare heuristics of edge\[^:\]*:" "profile_estimate"} } */ diff --git a/gcc/testsuite/gcc.dg/predict-3.c b/gcc/testsuite/gcc.dg/predict-3.c index 08db59a..663f141 100644 --- a/gcc/testsuite/gcc.dg/predict-3.c +++ b/gcc/testsuite/gcc.dg/predict-3.c @@ -25,4 +25,4 @@ void foo (int bound) } } -/* { dg-final { scan-tree-dump-times "loop iv compare heuristics: 98.0%" 3 "profile_estimate"} } */ +/* { dg-final { scan-tree-dump-times "loop iv compare heuristics of edge\[^:\]*: 98.0%" 3 "profile_estimate"} } */ diff --git a/gcc/testsuite/gcc.dg/predict-4.c b/gcc/testsuite/gcc.dg/predict-4.c index 3e7fb74..5779da3 100644 --- a/gcc/testsuite/gcc.dg/predict-4.c +++ b/gcc/testsuite/gcc.dg/predict-4.c @@ -15,4 +15,4 @@ void foo (int bound) } } -/* { dg-final { scan-tree-dump "loop iv compare heuristics: 50.0%" "profile_estimate"} } */ +/* { dg-final { scan-tree-dump "loop iv compare heuristics of edge\[^:\]*: 50.0%" "profile_estimate"} } */ diff --git a/gcc/testsuite/gcc.dg/predict-5.c b/gcc/testsuite/gcc.dg/predict-5.c index 32178a8..56ada30 100644 --- a/gcc/testsuite/gcc.dg/predict-5.c +++ b/gcc/testsuite/gcc.dg/predict-5.c @@ -21,4 +21,4 @@ void foo (int base, int bound) } } -/* { dg-final { scan-tree-dump-times "loop iv compare heuristics: 98.0%" 4 "profile_estimate"} } */ +/* { dg-final { scan-tree-dump-times "loop iv compare heuristics of edge\[^:\]*: 98.0%" 4 "profile_estimate"} } */ diff --git a/gcc/testsuite/gcc.dg/predict-6.c b/gcc/testsuite/gcc.dg/predict-6.c index 16ad16f..9ed41ed 100644 --- a/gcc/testsuite/gcc.dg/predict-6.c +++ b/gcc/testsuite/gcc.dg/predict-6.c @@ -21,4 +21,4 @@ void foo (int base, int bound) } } -/* { dg-final { scan-tree-dump-times "loop iv compare heuristics: 2.0%" 4 "profile_estimate"} } */ +/* { dg-final { scan-tree-dump-times "loop iv compare heuristics of edge\[^:\]*: 2.0%" 4 "profile_estimate"} } */ diff --git a/gcc/testsuite/gcc.dg/predict-7.c b/gcc/testsuite/gcc.dg/predict-7.c index a0ea37b..fe34ca5 100644 --- a/gcc/testsuite/gcc.dg/predict-7.c +++ b/gcc/testsuite/gcc.dg/predict-7.c @@ -13,4 +13,4 @@ void foo (int base) bar (i); } -/* { dg-final { scan-tree-dump-times "loop branch heuristics" 0 "profile_estimate"} } */ +/* { dg-final { scan-tree-dump-times "loop branch heuristics of edge\[^:\]*" 0 "profile_estimate"} } */ |