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| author | Richard Biener <rguenther@suse.de> | 2022-01-05 10:14:52 +0100 |
|---|---|---|
| committer | Richard Biener <rguenther@suse.de> | 2022-01-05 11:56:36 +0100 |
| commit | 1021b72bf6542f3c08e5404b65063216ee1b06f7 (patch) | |
| tree | 95640fc940dbfa2256cedfcb893632052a2619c6 /gcc | |
| parent | a4c2e62d60f47d47cdd94951e16b0de50495cdab (diff) | |
| download | gcc-1021b72bf6542f3c08e5404b65063216ee1b06f7.zip gcc-1021b72bf6542f3c08e5404b65063216ee1b06f7.tar.gz gcc-1021b72bf6542f3c08e5404b65063216ee1b06f7.tar.bz2 | |
tree-optimization/103816 - detect offset overflow in SLP group analysis
This makes sure to detect overflow when computing DR_GROUP_GAP
and DR_GROUP_SIZE more thoroughly so artificial testcases like the
added one are not fooling the existing check.
2022-01-05 Richard Biener <rguenther@suse.de>
PR tree-optimization/103816
* tree-vect-data-refs.c (vect_analyze_group_access_1): Also
check DR_GROUP_GAP compute for overflow and representability.
* gcc.dg/torture/pr103816.c: New testcase.
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/testsuite/gcc.dg/torture/pr103816.c | 10 | ||||
| -rw-r--r-- | gcc/tree-vect-data-refs.c | 15 |
2 files changed, 24 insertions, 1 deletions
diff --git a/gcc/testsuite/gcc.dg/torture/pr103816.c b/gcc/testsuite/gcc.dg/torture/pr103816.c new file mode 100644 index 0000000..769036a --- /dev/null +++ b/gcc/testsuite/gcc.dg/torture/pr103816.c @@ -0,0 +1,10 @@ +/* { dg-do compile } */ +/* { dg-additional-options "-w" } */ + +extern struct { + unsigned char a; + unsigned char b; + unsigned char c; + unsigned char d; +} g[]; +void main() { g[0].b = (g[0].b & g[4].b) * g[2305843009213693952ULL].c; } diff --git a/gcc/tree-vect-data-refs.c b/gcc/tree-vect-data-refs.c index 2b3ec62..dd20ed9 100644 --- a/gcc/tree-vect-data-refs.c +++ b/gcc/tree-vect-data-refs.c @@ -2721,7 +2721,20 @@ vect_analyze_group_access_1 (vec_info *vinfo, dr_vec_info *dr_info) /* Check that the distance between two accesses is equal to the type size. Otherwise, we have gaps. */ diff = (TREE_INT_CST_LOW (DR_INIT (data_ref)) - - TREE_INT_CST_LOW (prev_init)) / type_size; + - TREE_INT_CST_LOW (prev_init)) / type_size; + if (diff < 1 || diff > UINT_MAX) + { + /* For artificial testcases with array accesses with large + constant indices we can run into overflow issues which + can end up fooling the groupsize constraint below so + check the individual gaps (which are represented as + unsigned int) as well. */ + if (dump_enabled_p ()) + dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location, + "interleaved access with gap larger " + "than representable\n"); + return false; + } if (diff != 1) { /* FORNOW: SLP of accesses with gaps is not supported. */ |