diff options
| author | Andrew MacLeod <amacleod@redhat.com> | 2023-03-23 10:28:34 -0400 |
|---|---|---|
| committer | Andrew MacLeod <amacleod@redhat.com> | 2023-03-24 09:11:09 -0400 |
| commit | 0409aa5a2de9ce3164933814a4a7adc91f6acb96 (patch) | |
| tree | 0cd410bc9183c6ceaaccf083f61c04d7b60fd52f | |
| parent | ed626f18b189920aeed9974aded3f9cb6f25b543 (diff) | |
| download | gcc-0409aa5a2de9ce3164933814a4a7adc91f6acb96.zip gcc-0409aa5a2de9ce3164933814a4a7adc91f6acb96.tar.gz gcc-0409aa5a2de9ce3164933814a4a7adc91f6acb96.tar.bz2 | |
Ranger cache dominator queries should ignore backedges.
When querying dominators for cache values, ignore back edges in
read-only mode.
PR tree-optimization/109238
gcc/
* gimple-range-cache.cc (ranger_cache::resolve_dom): Ignore
predecessors which this block dominates.
gcc/testsuite/
* gcc.dg/pr109238.c: New.
| -rw-r--r-- | gcc/gimple-range-cache.cc | 5 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.dg/pr109238.c | 16 |
2 files changed, 21 insertions, 0 deletions
diff --git a/gcc/gimple-range-cache.cc b/gcc/gimple-range-cache.cc index cc56fd4..6a098d8 100644 --- a/gcc/gimple-range-cache.cc +++ b/gcc/gimple-range-cache.cc @@ -1404,6 +1404,11 @@ ranger_cache::resolve_dom (vrange &r, tree name, basic_block bb) Value_Range er (TREE_TYPE (name)); FOR_EACH_EDGE (e, ei, bb->preds) { + // If the predecessor is dominated by this block, then there is a back + // edge, and won't provide anything useful. We'll actually end up with + // VARYING as we will not resolve this node. + if (dominated_by_p (CDI_DOMINATORS, e->src, bb)) + continue; edge_range (er, e, name, RFD_READ_ONLY); r.union_ (er); } diff --git a/gcc/testsuite/gcc.dg/pr109238.c b/gcc/testsuite/gcc.dg/pr109238.c new file mode 100644 index 0000000..0cad823 --- /dev/null +++ b/gcc/testsuite/gcc.dg/pr109238.c @@ -0,0 +1,16 @@ +/* PR tree-optimization/109238 */ +/* { dg-do compile } */ +/* { dg-options "-O2 -Wall" } */ + +void foo (void *) __attribute__((noreturn)); +void bar (void *); + +void +baz (void *p) +{ + void *c = __builtin_realloc (p, 16); + if (c) + foo (c); + for (;;) + bar (__builtin_realloc (p, 8)); /* { dg-bogus "pointer 'p' may be used after '__builtin_realloc'" } */ +} |