diff options
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/ChangeLog | 6 | ||||
| -rw-r--r-- | gcc/predict.c | 30 |
2 files changed, 35 insertions, 1 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 86cf148..3a75b803 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,5 +1,11 @@ 2016-05-27 Jan Hubicka <hubicka@ucw.cz> + * predict.c (edge_predicted_by_p): New function. + (predict_paths_for_bb): Do not put multiple predictions of the same type + on one edge. + +2016-05-27 Jan Hubicka <hubicka@ucw.cz> + * tree-ssa-loop-niter.c (number_of_iterations_exit): Revert accidental commit. diff --git a/gcc/predict.c b/gcc/predict.c index f1e22ae..22ec8a0 100644 --- a/gcc/predict.c +++ b/gcc/predict.c @@ -478,6 +478,31 @@ gimple_predicted_by_p (const_basic_block bb, enum br_predictor predictor) return false; } +/* Return true if the one of outgoing edges is already predicted by + PREDICTOR for edge E predicted as TAKEN. */ + +bool +edge_predicted_by_p (edge e, enum br_predictor predictor, bool taken) +{ + struct edge_prediction *i; + basic_block bb = e->src; + edge_prediction **preds = bb_predictions->get (bb); + if (!preds) + return false; + + int probability = predictor_info[(int) predictor].hitrate; + + if (taken != TAKEN) + probability = REG_BR_PROB_BASE - probability; + + for (i = *preds; i; i = i->ep_next) + if (i->ep_predictor == predictor + && i->ep_edge == e + && i->ep_probability == probability) + return true; + return false; +} + /* Return true when the probability of edge is reliable. The profile guessing code is good at predicting branch outcome (ie. @@ -2415,7 +2440,10 @@ 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) - predict_edge_def (e, pred, taken); + { + if (!edge_predicted_by_p (e, pred, taken)) + predict_edge_def (e, pred, taken); + } else if (bitmap_set_bit (visited, e->src->index)) predict_paths_for_bb (e->src, e->src, pred, taken, visited); } |