diff options
Diffstat (limited to 'gcc/predict.c')
| -rw-r--r-- | gcc/predict.c | 76 |
1 files changed, 63 insertions, 13 deletions
diff --git a/gcc/predict.c b/gcc/predict.c index a7ae977..4c4bba5 100644 --- a/gcc/predict.c +++ b/gcc/predict.c @@ -595,10 +595,11 @@ gimple_predict_edge (edge e, enum br_predictor predictor, int probability) } } -/* Filter edge predictions PREDS by a function FILTER. DATA are passed - to the filter function. */ +/* Filter edge predictions PREDS by a function FILTER: if FILTER return false + the prediction is removed. + DATA are passed to the filter function. */ -void +static void filter_predictions (edge_prediction **preds, bool (*filter) (edge_prediction *, void *), void *data) { @@ -627,10 +628,10 @@ filter_predictions (edge_prediction **preds, /* Filter function predicate that returns true for a edge predicate P if its edge is equal to DATA. */ -bool -equal_edge_p (edge_prediction *p, void *data) +static bool +not_equal_edge_p (edge_prediction *p, void *data) { - return p->ep_edge == (edge)data; + return p->ep_edge != (edge)data; } /* Remove all predictions on given basic block that are attached @@ -642,7 +643,7 @@ remove_predictions_associated_with_edge (edge e) return; edge_prediction **preds = bb_predictions->get (e->src); - filter_predictions (preds, equal_edge_p, e); + filter_predictions (preds, not_equal_edge_p, e); } /* Clears the list of predictions stored for BB. */ @@ -3121,6 +3122,35 @@ tree_guess_outgoing_edge_probabilities (basic_block bb) bb_predictions = NULL; } +/* Filter function predicate that returns true for a edge predicate P + if its edge is equal to DATA. */ + +static bool +not_loop_guard_equal_edge_p (edge_prediction *p, void *data) +{ + return p->ep_edge != (edge)data || p->ep_predictor != PRED_LOOP_GUARD; +} + +/* Predict edge E with PRED unless it is already predicted by some predictor + considered equivalent. */ + +static void +maybe_predict_edge (edge e, enum br_predictor pred, enum prediction taken) +{ + if (edge_predicted_by_p (e, pred, taken)) + return; + if (pred == PRED_LOOP_GUARD + && edge_predicted_by_p (e, PRED_LOOP_GUARD_WITH_RECURSION, taken)) + return; + /* Consider PRED_LOOP_GUARD_WITH_RECURSION superrior to LOOP_GUARD. */ + if (pred == PRED_LOOP_GUARD_WITH_RECURSION) + { + edge_prediction **preds = bb_predictions->get (e->src); + if (preds) + filter_predictions (preds, not_loop_guard_equal_edge_p, e); + } + predict_edge_def (e, pred, taken); +} /* Predict edges to successors of CUR whose sources are not postdominated by BB by PRED and recurse to all postdominators. */ @@ -3176,10 +3206,7 @@ predict_paths_for_bb (basic_block cur, basic_block bb, regions that are only reachable by abnormal edges. We simply prevent visiting given BB twice. */ if (found) - { - if (!edge_predicted_by_p (e, pred, taken)) - predict_edge_def (e, pred, taken); - } + maybe_predict_edge (e, pred, taken); else if (bitmap_set_bit (visited, e->src->index)) predict_paths_for_bb (e->src, e->src, pred, taken, visited, in_loop); } @@ -3222,7 +3249,7 @@ predict_paths_leading_to_edge (edge e, enum br_predictor pred, if (!has_nonloop_edge) predict_paths_for_bb (bb, bb, pred, taken, auto_bitmap (), in_loop); else - predict_edge_def (e, pred, taken); + maybe_predict_edge (e, pred, taken); } /* This is used to carry information about basic blocks. It is @@ -3892,7 +3919,30 @@ estimate_bb_frequencies (bool force) cfun->cfg->count_max = profile_count::uninitialized (); FOR_BB_BETWEEN (bb, ENTRY_BLOCK_PTR_FOR_FN (cfun), NULL, next_bb) { - sreal tmp = BLOCK_INFO (bb)->frequency * freq_max + sreal (1, -1); + sreal tmp = BLOCK_INFO (bb)->frequency; + if (tmp >= 1) + { + gimple_stmt_iterator gsi; + tree decl; + + /* Self recursive calls can not have frequency greater than 1 + or program will never terminate. This will result in an + inconsistent bb profile but it is better than greatly confusing + IPA cost metrics. */ + for (gsi = gsi_start_bb (bb); !gsi_end_p (gsi); gsi_next (&gsi)) + if (is_gimple_call (gsi_stmt (gsi)) + && (decl = gimple_call_fndecl (gsi_stmt (gsi))) != NULL + && recursive_call_p (current_function_decl, decl)) + { + if (dump_file) + fprintf (dump_file, "Dropping frequency of recursive call" + " in bb %i from %f\n", bb->index, + tmp.to_double ()); + tmp = (sreal)9 / (sreal)10; + break; + } + } + tmp = tmp * freq_max + sreal (1, -1); profile_count count = profile_count::from_gcov_type (tmp.to_int ()); /* If we have profile feedback in which this function was never |