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| author | Jakub Jelinek <jakub@redhat.com> | 2022-03-30 10:21:16 +0200 |
|---|---|---|
| committer | Jakub Jelinek <jakub@redhat.com> | 2022-03-30 10:21:16 +0200 |
| commit | 387e818cda0ffde86f624228c3da1ab28f453685 (patch) | |
| tree | 8df9a9b6da26884063bede81345849558b8c9633 /gcc | |
| parent | 410f39f56c14b195f066b9a18a3c6e8ffa03f848 (diff) | |
| download | gcc-387e818cda0ffde86f624228c3da1ab28f453685.zip gcc-387e818cda0ffde86f624228c3da1ab28f453685.tar.gz gcc-387e818cda0ffde86f624228c3da1ab28f453685.tar.bz2 | |
store-merging: Avoid ICEs on roughly ~0ULL/8 sized stores [PR105094]
On the following testcase on 64-bit targets, store-merging sees
a MEM_REF store from {} ctor with "negative" bitsize where bitoff + bitsize
wraps around to very small end offset. This later confuses the code
so that it allocates just a few bytes of memory but fills in huge amounts of
it. Later on there is a param_store_merging_max_size size check but due to
the wrap-around we pass that.
The following patch punts on such large bitsizes.
2022-03-30 Jakub Jelinek <jakub@redhat.com>
PR tree-optimization/105094
* gimple-ssa-store-merging.cc (mem_valid_for_store_merging): Punt if
bitsize <= 0 rather than just == 0.
* gcc.dg/pr105094.c: New test.
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/gimple-ssa-store-merging.cc | 2 | ||||
| -rw-r--r-- | gcc/testsuite/gcc.dg/pr105094.c | 13 |
2 files changed, 14 insertions, 1 deletions
diff --git a/gcc/gimple-ssa-store-merging.cc b/gcc/gimple-ssa-store-merging.cc index e2e2157..b952ce5 100644 --- a/gcc/gimple-ssa-store-merging.cc +++ b/gcc/gimple-ssa-store-merging.cc @@ -4940,7 +4940,7 @@ mem_valid_for_store_merging (tree mem, poly_uint64 *pbitsize, tree base_addr = get_inner_reference (mem, &bitsize, &bitpos, &offset, &mode, &unsignedp, &reversep, &volatilep); *pbitsize = bitsize; - if (known_eq (bitsize, 0)) + if (known_le (bitsize, 0)) return NULL_TREE; if (TREE_CODE (mem) == COMPONENT_REF diff --git a/gcc/testsuite/gcc.dg/pr105094.c b/gcc/testsuite/gcc.dg/pr105094.c new file mode 100644 index 0000000..da6dc17 --- /dev/null +++ b/gcc/testsuite/gcc.dg/pr105094.c @@ -0,0 +1,13 @@ +/* PR tree-optimization/105094 */ +/* { dg-do compile } */ +/* { dg-options "-O2" } */ + +struct S { short a; char b[~(__SIZE_TYPE__)0 / __CHAR_BIT__ - 1]; }; +void bar (struct S *); + +void +foo (void) +{ + struct S s = { 5 }; + bar (&s); +} |