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| author | Richard Biener <rguenther@suse.de> | 2023-04-24 13:31:07 +0200 |
|---|---|---|
| committer | Richard Biener <rguenther@suse.de> | 2023-04-25 14:23:59 +0200 |
| commit | 6d4bd27a60447c7505cb4783e675e98a191a8904 (patch) | |
| tree | bfc20066fc0f6c3928811d17b2df6471b8749d44 /gcc | |
| parent | 97f8f2d0a0384d377ca46da88495f9a3d18d4415 (diff) | |
| download | gcc-6d4bd27a60447c7505cb4783e675e98a191a8904.zip gcc-6d4bd27a60447c7505cb4783e675e98a191a8904.tar.gz gcc-6d4bd27a60447c7505cb4783e675e98a191a8904.tar.bz2 | |
rtl-optimization/109585 - alias analysis typo
When r10-514-gc6b84edb6110dd2b4fb improved access path analysis
it introduced a typo that triggers when there's an access to a
trailing array in the first access path leading to false
disambiguation.
PR rtl-optimization/109585
* tree-ssa-alias.cc (aliasing_component_refs_p): Fix typo.
* gcc.dg/torture/pr109585.c: New testcase.
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/testsuite/gcc.dg/torture/pr109585.c | 33 | ||||
| -rw-r--r-- | gcc/tree-ssa-alias.cc | 2 |
2 files changed, 34 insertions, 1 deletions
diff --git a/gcc/testsuite/gcc.dg/torture/pr109585.c b/gcc/testsuite/gcc.dg/torture/pr109585.c new file mode 100644 index 0000000..f92de7c --- /dev/null +++ b/gcc/testsuite/gcc.dg/torture/pr109585.c @@ -0,0 +1,33 @@ +/* { dg-do run } */ + +#include <stdlib.h> + +struct P { + long v; + struct P *n; +}; + +struct F { + long x; + struct P fam[]; +}; + +int __attribute__((noipa)) +f(struct F *f, int i) +{ + struct P *p = f->fam; + asm("" : "+r"(f): "r"(p)); + p->v = 0; + p->n = 0; + return f->fam->n != 0; +} + +int +main() +{ + struct F *m = malloc (sizeof (long) + 2 * sizeof (struct P)); + m->fam[0].n = &m->fam[1]; + if (f (m, 0)) + abort (); + return 0; +} diff --git a/gcc/tree-ssa-alias.cc b/gcc/tree-ssa-alias.cc index 81bc51e..8a1ec90 100644 --- a/gcc/tree-ssa-alias.cc +++ b/gcc/tree-ssa-alias.cc @@ -1330,7 +1330,7 @@ aliasing_component_refs_p (tree ref1, /* If we didn't find a common base, try the other way around. */ if (cmp_outer <= 0 || (end_struct_ref1 - && compare_type_sizes (TREE_TYPE (end_struct_ref1), type1) <= 0)) + && compare_type_sizes (TREE_TYPE (end_struct_ref1), type2) <= 0)) { int res = aliasing_component_refs_walk (ref2, type2, base2, offset2, max_size2, |