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| author | Richard Biener <rguenther@suse.de> | 2021-04-27 09:41:38 +0200 |
|---|---|---|
| committer | Richard Biener <rguenther@suse.de> | 2021-04-27 10:30:06 +0200 |
| commit | acfe5290406cc70485df8899d14982278a9371f8 (patch) | |
| tree | f52f3166eb0719caad9159e11b06eb35b6f394a7 /gcc | |
| parent | 71c8aaf29bb122ebe5e67c84903fd23ff05f04ec (diff) | |
| download | gcc-acfe5290406cc70485df8899d14982278a9371f8.zip gcc-acfe5290406cc70485df8899d14982278a9371f8.tar.gz gcc-acfe5290406cc70485df8899d14982278a9371f8.tar.bz2 | |
tree-optimization/100278 - handle mismatched code in TBAA adjust of PRE
PRE has code to adjust TBAA behavior for refs that expects the base
operation code to match. The testcase shows a case where we have
a VAR_DECL vs. a MEM_REF so add code to give up in such cases.
2021-04-27 Richard Biener <rguenther@suse.de>
PR tree-optimization/100278
* tree-ssa-pre.c (compute_avail): Give up when we cannot
adjust TBAA beacuse of mismatching bases.
* gcc.dg/tree-ssa/pr100278.c: New testcase.
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/testsuite/gcc.dg/tree-ssa/pr100278.c | 17 | ||||
| -rw-r--r-- | gcc/tree-ssa-pre.c | 10 |
2 files changed, 27 insertions, 0 deletions
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr100278.c b/gcc/testsuite/gcc.dg/tree-ssa/pr100278.c new file mode 100644 index 0000000..8d70228 --- /dev/null +++ b/gcc/testsuite/gcc.dg/tree-ssa/pr100278.c @@ -0,0 +1,17 @@ +/* { dg-do compile } */ +/* { dg-options "-O2" } */ + +void a() +{ +#if defined __s390__ + register int b asm("r5"); +#elif defined __x86_64__ + register int b asm("eax"); +#else + volatile int b; +#endif + if (b) + b = 1; + for (; b;) + ; +} diff --git a/gcc/tree-ssa-pre.c b/gcc/tree-ssa-pre.c index 2803b58..2d22535 100644 --- a/gcc/tree-ssa-pre.c +++ b/gcc/tree-ssa-pre.c @@ -4151,6 +4151,16 @@ compute_avail (void) if (ref->set == set || alias_set_subset_of (set, ref->set)) ; + else if (ref1->opcode != ref2->opcode + || (ref1->opcode != MEM_REF + && ref1->opcode != TARGET_MEM_REF)) + { + /* With mismatching base opcodes or bases + other than MEM_REF or TARGET_MEM_REF we + can't do any easy TBAA adjustment. */ + operands.release (); + continue; + } else if (alias_set_subset_of (ref->set, set)) { ref->set = set; |