diff options
| -rw-r--r-- | gcc/ChangeLog | 11 | ||||
| -rw-r--r-- | gcc/testsuite/ChangeLog | 7 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.dg/tree-ssa/pr67755.c | 25 | ||||
| -rw-r--r-- | gcc/tree-ssa-threadupdate.c | 21 |
4 files changed, 62 insertions, 2 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 6423a37..f8f818b 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,14 @@ +2016-01-12 Jeff Law <law@redhat.com> + + PR tree-optimization/pr67755 + * tree-ssa-threadupdate.c (struct ssa_local_info_t): Add new field + "need_profile_correction". + (thread_block_1): Initialize new field to false by default. If we + have multiple thread paths through a common joiner to different + final targets, then set new field to true. + (compute_path_counts): Only do count adjustment when it's really + needed. + 2016-01-12 Sandra Loosemore <sandra@codesourcery.com> * doc/invoke.texi (Spec Files): Move section down in file, past diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 11f3b0c..240fae7 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,4 +1,9 @@ -2015-01-13 Thomas Preud'homme <thomas.preudhomme@arm.com> +2016-01-13 Jeff Law <law@redhat.com> + + PR tree-optimization/67755 + * gcc.dg/tree-ssa/pr67755.c: New test. + +2016-01-13 Thomas Preud'homme <thomas.preudhomme@arm.com> * gcc.c-torture/unsorted/dump-noaddr.x (dump_compare): Replace static pass number in output by a star. diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr67755.c b/gcc/testsuite/gcc.dg/tree-ssa/pr67755.c new file mode 100644 index 0000000..64ffd0b --- /dev/null +++ b/gcc/testsuite/gcc.dg/tree-ssa/pr67755.c @@ -0,0 +1,25 @@ +/* { dg-do compile } */ +/* { dg-options "-O1 -fdump-tree-dom2-details-blocks" } */ +/* We want to verify no outgoing edge from a conditional + has a probability of 100%. */ +/* { dg-final { scan-tree-dump-not "succ:\[ \]+. .100.0%. .\(TRUE|FALSE\)_VALUE" "dom2"} } */ + + +void (*zend_block_interruptions) (void); + +int * _zend_mm_alloc_int (int * heap, long int size) +{ + int *best_fit; + long int true_size = (size < 15 ? 32 : size); + + if (zend_block_interruptions) + zend_block_interruptions (); + + if (__builtin_expect ((true_size < 543), 1)) + best_fit = heap + 2; + else + best_fit = heap; + + return best_fit; +} + diff --git a/gcc/tree-ssa-threadupdate.c b/gcc/tree-ssa-threadupdate.c index 1bf9ae6..4783c4b 100644 --- a/gcc/tree-ssa-threadupdate.c +++ b/gcc/tree-ssa-threadupdate.c @@ -239,6 +239,11 @@ struct ssa_local_info_t /* Blocks duplicated for the thread. */ bitmap duplicate_blocks; + + /* When we have multiple paths through a joiner which reach different + final destinations, then we may need to correct for potential + profile insanities. */ + bool need_profile_correction; }; /* Passes which use the jump threading code register jump threading @@ -826,7 +831,8 @@ compute_path_counts (struct redirection_data *rd, So ensure that this path's path_out_count is at least the difference between elast->count and nonpath_count. Otherwise the edge counts after threading will not be sane. */ - if (has_joiner && path_out_count < elast->count - nonpath_count) + if (local_info->need_profile_correction + && has_joiner && path_out_count < elast->count - nonpath_count) { path_out_count = elast->count - nonpath_count; /* But neither can we go above the minimum count along the path @@ -1492,6 +1498,7 @@ thread_block_1 (basic_block bb, bool noloop_only, bool joiners) ssa_local_info_t local_info; local_info.duplicate_blocks = BITMAP_ALLOC (NULL); + local_info.need_profile_correction = false; /* To avoid scanning a linear array for the element we need we instead use a hash table. For normal code there should be no noticeable @@ -1502,6 +1509,7 @@ thread_block_1 (basic_block bb, bool noloop_only, bool joiners) /* Record each unique threaded destination into a hash table for efficient lookups. */ + edge last = NULL; FOR_EACH_EDGE (e, ei, bb->preds) { if (e->aux == NULL) @@ -1555,6 +1563,17 @@ thread_block_1 (basic_block bb, bool noloop_only, bool joiners) /* Insert the outgoing edge into the hash table if it is not already in the hash table. */ lookup_redirection_data (e, INSERT); + + /* When we have thread paths through a common joiner with different + final destinations, then we may need corrections to deal with + profile insanities. See the big comment before compute_path_counts. */ + if ((*path)[1]->type == EDGE_COPY_SRC_JOINER_BLOCK) + { + if (!last) + last = e2; + else if (e2 != last) + local_info.need_profile_correction = true; + } } /* We do not update dominance info. */ |