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| author | Martin Liska <mliska@suse.cz> | 2017-06-21 14:51:46 +0200 |
|---|---|---|
| committer | Martin Liska <marxin@gcc.gnu.org> | 2017-06-21 12:51:46 +0000 |
| commit | e59a1c22fb249388e82b4fd004f33615abe36d2e (patch) | |
| tree | 0ba9b3f978dc6746d354dccdfb340b58bb47cbfb /gcc/predict.c | |
| parent | ff9baa5f1c532a43d7d14a800f5a4a5c5757dca6 (diff) | |
| download | gcc-e59a1c22fb249388e82b4fd004f33615abe36d2e.zip gcc-e59a1c22fb249388e82b4fd004f33615abe36d2e.tar.gz gcc-e59a1c22fb249388e82b4fd004f33615abe36d2e.tar.bz2 | |
Make early return predictor more precise.
2017-06-21 Martin Liska <mliska@suse.cz>
PR tree-optimization/79489
* gimplify.c (maybe_add_early_return_predict_stmt): New
function.
(gimplify_return_expr): Call the function.
* predict.c (tree_estimate_probability_bb): Remove handling
of early return.
* predict.def: Update comment about early return predictor.
* gimple-predict.h (is_gimple_predict): New function.
* predict.def: Change default value of early return to 66.
* tree-tailcall.c (find_tail_calls): Skip GIMPLE_PREDICT
statements.
* passes.def: Put pass_strip_predict_hints to the beginning of
IPA passes.
From-SVN: r249450
Diffstat (limited to 'gcc/predict.c')
| -rw-r--r-- | gcc/predict.c | 41 |
1 files changed, 0 insertions, 41 deletions
diff --git a/gcc/predict.c b/gcc/predict.c index 60d1a09..790be9f 100644 --- a/gcc/predict.c +++ b/gcc/predict.c @@ -2739,7 +2739,6 @@ tree_estimate_probability_bb (basic_block bb, bool local_only) { edge e; edge_iterator ei; - gimple *last; FOR_EACH_EDGE (e, ei, bb->succs) { @@ -2766,46 +2765,6 @@ tree_estimate_probability_bb (basic_block bb, bool local_only) } } - /* Predict early returns to be probable, as we've already taken - care for error returns and other cases are often used for - fast paths through function. - - Since we've already removed the return statements, we are - looking for CFG like: - - if (conditional) - { - .. - goto return_block - } - some other blocks - return_block: - return_stmt. */ - if (e->dest != bb->next_bb - && e->dest != EXIT_BLOCK_PTR_FOR_FN (cfun) - && single_succ_p (e->dest) - && single_succ_edge (e->dest)->dest == EXIT_BLOCK_PTR_FOR_FN (cfun) - && (last = last_stmt (e->dest)) != NULL - && gimple_code (last) == GIMPLE_RETURN) - { - edge e1; - edge_iterator ei1; - - if (single_succ_p (bb)) - { - FOR_EACH_EDGE (e1, ei1, bb->preds) - if (!predicted_by_p (e1->src, PRED_NULL_RETURN) - && !predicted_by_p (e1->src, PRED_CONST_RETURN) - && !predicted_by_p (e1->src, PRED_NEGATIVE_RETURN)) - predict_edge_def (e1, PRED_TREE_EARLY_RETURN, NOT_TAKEN); - } - else - if (!predicted_by_p (e->src, PRED_NULL_RETURN) - && !predicted_by_p (e->src, PRED_CONST_RETURN) - && !predicted_by_p (e->src, PRED_NEGATIVE_RETURN)) - predict_edge_def (e, PRED_TREE_EARLY_RETURN, NOT_TAKEN); - } - /* Look for block we are guarding (ie we dominate it, but it doesn't postdominate us). */ if (e->dest != EXIT_BLOCK_PTR_FOR_FN (cfun) && e->dest != bb |