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| author | Teresa Johnson <tejohnson@google.com> | 2013-04-29 13:22:46 +0000 |
|---|---|---|
| committer | Teresa Johnson <tejohnson@gcc.gnu.org> | 2013-04-29 13:22:46 +0000 |
| commit | f41f80f90846d26a89ed5a6440bc283b745235ac (patch) | |
| tree | 9daf54908866e15052bfcfc011bc4753b4b363fb /gcc/tree-inline.c | |
| parent | 315bbd2e3c15dea3528259be2aee2876dec33843 (diff) | |
| download | gcc-f41f80f90846d26a89ed5a6440bc283b745235ac.zip gcc-f41f80f90846d26a89ed5a6440bc283b745235ac.tar.gz gcc-f41f80f90846d26a89ed5a6440bc283b745235ac.tar.bz2 | |
This patch fixes PR bootstrap/57077.
This patch fixes PR bootstrap/57077. Certain new uses of apply_probability
are actually scaling the counts up, and the scale factor should not
be treated as a probability as the value may exceed REG_BR_PROB_BASE.
One example (from the PR) is when scaling counts up in LTO when merging
profiles. Another example I found when preparing the patch to use
the rounding divide in more places is when inlining COMDAT functions.
Add new helper function apply_scale that does the scaling without
the probability range check. I audited the new uses of apply_probability
and changed the calls as appropriate.
2013-04-29 Teresa Johnson <tejohnson@google.com>
PR bootstrap/57077
* basic-block.h (apply_scale): New function.
(apply_probability): Use apply_scale.
* gimple-streamer-in.c (input_bb): Ditto.
* lto-streamer-in.c (input_cfg): Ditto.
* lto-cgraph.c (merge_profile_summaries): Ditto.
* tree-optimize.c (execute_fixup_cfg): Ditto.
* tree-inline.c (copy_bb): Update comment to use
apply_scale.
(copy_edges_for_bb): Ditto.
(copy_cfg_body): Ditto.
From-SVN: r198416
Diffstat (limited to 'gcc/tree-inline.c')
| -rw-r--r-- | gcc/tree-inline.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/gcc/tree-inline.c b/gcc/tree-inline.c index c358cbe..69455ce 100644 --- a/gcc/tree-inline.c +++ b/gcc/tree-inline.c @@ -1519,7 +1519,7 @@ copy_bb (copy_body_data *id, basic_block bb, int frequency_scale, basic_block_info automatically. */ copy_basic_block = create_basic_block (NULL, (void *) 0, (basic_block) prev->aux); - /* Update to use apply_probability(). */ + /* Update to use apply_scale(). */ copy_basic_block->count = bb->count * count_scale / REG_BR_PROB_BASE; /* We are going to rebuild frequencies from scratch. These values @@ -1891,7 +1891,7 @@ copy_edges_for_bb (basic_block bb, gcov_type count_scale, basic_block ret_bb, && old_edge->dest->aux != EXIT_BLOCK_PTR) flags |= EDGE_FALLTHRU; new_edge = make_edge (new_bb, (basic_block) old_edge->dest->aux, flags); - /* Update to use apply_probability(). */ + /* Update to use apply_scale(). */ new_edge->count = old_edge->count * count_scale / REG_BR_PROB_BASE; new_edge->probability = old_edge->probability; } @@ -2278,7 +2278,7 @@ copy_cfg_body (copy_body_data * id, gcov_type count, int frequency_scale, incoming_frequency += EDGE_FREQUENCY (e); incoming_count += e->count; } - /* Update to use apply_probability(). */ + /* Update to use apply_scale(). */ incoming_count = incoming_count * count_scale / REG_BR_PROB_BASE; /* Update to use EDGE_FREQUENCY. */ incoming_frequency |