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| author | Jakub Jelinek <jakub@redhat.com> | 2020-03-05 08:00:04 +0100 |
|---|---|---|
| committer | Jakub Jelinek <jakub@redhat.com> | 2020-03-05 08:00:04 +0100 |
| commit | fe19699ae2883b252d30f98481d32dabff00744b (patch) | |
| tree | 156e2e7833a639349d5dd27e30c93c0f60b8ab49 /gcc/tree-ssa-sccvn.c | |
| parent | cb2409c60aeff498064346f85165531a3bbead14 (diff) | |
| download | gcc-fe19699ae2883b252d30f98481d32dabff00744b.zip gcc-fe19699ae2883b252d30f98481d32dabff00744b.tar.gz gcc-fe19699ae2883b252d30f98481d32dabff00744b.tar.bz2 | |
sccvn: Fix handling of POINTER_PLUS_EXPR in memset offset [PR93582]
> > where POINTER_PLUS_EXPR last operand has sizetype type, thus unsigned,
> > and in the testcase gimple_assign_rhs2 (def) is thus 0xf000000000000001ULL
> > which multiplied by 8 doesn't fit into signed HWI. If it would be treated
> > as signed offset instead, it would fit (-0xfffffffffffffffLL, multiplied
> > by 8 is -0x7ffffffffffffff8LL). Unfortunately with the poly_int obfuscation
> > I'm not sure how to convert it from unsigned to signed poly_int.
>
> mem_ref_offset provides a boiler-plate for this:
>
> poly_offset_int::from (wi::to_poly_wide (TREE_OPERAND (t, 1)), SIGNED);
Thanks, that seems to work.
The test now works on both big-endian and little-endian.
2020-03-05 Richard Biener <rguenther@suse.de>
Jakub Jelinek <jakub@redhat.com>
PR tree-optimization/93582
* tree-ssa-sccvn.c (vn_reference_lookup_3): Treat POINTER_PLUS_EXPR
last operand as signed when looking for memset offset. Formatting
fix.
* gcc.dg/tree-ssa/pr93582-11.c: New test.
Co-authored-by: Richard Biener <rguenther@suse.de>
Diffstat (limited to 'gcc/tree-ssa-sccvn.c')
| -rw-r--r-- | gcc/tree-ssa-sccvn.c | 12 |
1 files changed, 8 insertions, 4 deletions
diff --git a/gcc/tree-ssa-sccvn.c b/gcc/tree-ssa-sccvn.c index 9ea30ef..b7174cd 100644 --- a/gcc/tree-ssa-sccvn.c +++ b/gcc/tree-ssa-sccvn.c @@ -2656,7 +2656,8 @@ vn_reference_lookup_3 (ao_ref *ref, tree vuse, void *data_, { poly_int64 soff; if (TREE_CODE (base) != MEM_REF - || !(mem_ref_offset (base) << LOG2_BITS_PER_UNIT).to_shwi (&soff)) + || !(mem_ref_offset (base) + << LOG2_BITS_PER_UNIT).to_shwi (&soff)) return (void *)-1; offset += soff; offset2 = 0; @@ -2666,10 +2667,13 @@ vn_reference_lookup_3 (ao_ref *ref, tree vuse, void *data_, if (is_gimple_assign (def) && gimple_assign_rhs_code (def) == POINTER_PLUS_EXPR && gimple_assign_rhs1 (def) == TREE_OPERAND (base, 0) - && poly_int_tree_p (gimple_assign_rhs2 (def)) - && (wi::to_poly_offset (gimple_assign_rhs2 (def)) - << LOG2_BITS_PER_UNIT).to_shwi (&offset2)) + && poly_int_tree_p (gimple_assign_rhs2 (def))) { + tree rhs2 = gimple_assign_rhs2 (def); + if (!(poly_offset_int::from (wi::to_poly_wide (rhs2), + SIGNED) + << LOG2_BITS_PER_UNIT).to_shwi (&offset2)) + return (void *)-1; ref2 = gimple_assign_rhs1 (def); if (TREE_CODE (ref2) == SSA_NAME) ref2 = SSA_VAL (ref2); |