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| author | Richard Biener <rguenther@suse.de> | 2020-09-21 14:04:25 +0200 |
|---|---|---|
| committer | Richard Biener <rguenther@suse.de> | 2020-09-21 14:06:36 +0200 |
| commit | 0df746afc50a47d1eb53a401e017c4373cf05641 (patch) | |
| tree | 8854bff3684494b1d8bf4e6c1dfba501017766e2 /gcc | |
| parent | d726ecd9554a805d4a5e044cb21ca23a7f7ca49f (diff) | |
| download | gcc-0df746afc50a47d1eb53a401e017c4373cf05641.zip gcc-0df746afc50a47d1eb53a401e017c4373cf05641.tar.gz gcc-0df746afc50a47d1eb53a401e017c4373cf05641.tar.bz2 | |
tree-optimization/97135 - fix dependence check in store-motion
The following fixes a dependence check where in the particular place
we cannot ignore self-dependences.
2020-09-21 Richard Biener <rguenther@suse.de>
PR tree-optimization/97135
* tree-ssa-loop-im.c (sm_seq_push_down): Do not ignore
self-dependences.
* gcc.dg/torture/pr97135.c: New testcase.
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/testsuite/gcc.dg/torture/pr97135.c | 21 | ||||
| -rw-r--r-- | gcc/tree-ssa-loop-im.c | 8 |
2 files changed, 26 insertions, 3 deletions
diff --git a/gcc/testsuite/gcc.dg/torture/pr97135.c b/gcc/testsuite/gcc.dg/torture/pr97135.c new file mode 100644 index 0000000..223f4d0 --- /dev/null +++ b/gcc/testsuite/gcc.dg/torture/pr97135.c @@ -0,0 +1,21 @@ +/* { dg-do run } */ + +long long e, *d = &e; +int a, b, c; + +int +main () +{ + for (; c <= 5; c++) + for (b = 0; b <= 5; b++) + { + for (a = 1; a <= 5; a++) + ; + *d = 0; + if (c) + break; + } + if (a != 6) + __builtin_abort (); + return 0; +} diff --git a/gcc/tree-ssa-loop-im.c b/gcc/tree-ssa-loop-im.c index f87c287..139c7e7 100644 --- a/gcc/tree-ssa-loop-im.c +++ b/gcc/tree-ssa-loop-im.c @@ -2232,9 +2232,11 @@ sm_seq_push_down (vec<seq_entry> &seq, unsigned ptr, unsigned *at) || (against.second == sm_other && against.from != NULL_TREE)) /* Found the tail of the sequence. */ break; - if (!refs_independent_p (memory_accesses.refs_list[new_cand.first], - memory_accesses.refs_list[against.first], - false)) + /* We may not ignore self-dependences here. */ + if (new_cand.first == against.first + || !refs_independent_p (memory_accesses.refs_list[new_cand.first], + memory_accesses.refs_list[against.first], + false)) /* ??? Prune new_cand from the list of refs to apply SM to. */ return false; std::swap (new_cand, against); |