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| author | Jakub Jelinek <jakub@redhat.com> | 2016-08-09 09:49:14 +0200 |
|---|---|---|
| committer | Jakub Jelinek <jakub@gcc.gnu.org> | 2016-08-09 09:49:14 +0200 |
| commit | 9e207d6fec83ee36458d59254d3fd40b3752bec2 (patch) | |
| tree | f9c8a787b868065680fcf3982a8ae8846c37d368 /gcc/tree-loop-distribution.c | |
| parent | 50bf47fdc08807bf8fc0362d677c8fc7dd4514b0 (diff) | |
| download | gcc-9e207d6fec83ee36458d59254d3fd40b3752bec2.zip gcc-9e207d6fec83ee36458d59254d3fd40b3752bec2.tar.gz gcc-9e207d6fec83ee36458d59254d3fd40b3752bec2.tar.bz2 | |
re PR tree-optimization/72824 (Signed floating point zero semantics broken at optimization level -O3 (tree-loop-distribute-patterns))
PR tree-optimization/72824
* tree-loop-distribution.c (const_with_all_bytes_same): Verify
real_zerop is not negative.
* gcc.c-torture/execute/ieee/pr72824.c: New test.
From-SVN: r239275
Diffstat (limited to 'gcc/tree-loop-distribution.c')
| -rw-r--r-- | gcc/tree-loop-distribution.c | 30 |
1 files changed, 29 insertions, 1 deletions
diff --git a/gcc/tree-loop-distribution.c b/gcc/tree-loop-distribution.c index 181e4e9..342b964 100644 --- a/gcc/tree-loop-distribution.c +++ b/gcc/tree-loop-distribution.c @@ -750,12 +750,40 @@ const_with_all_bytes_same (tree val) int i, len; if (integer_zerop (val) - || real_zerop (val) || (TREE_CODE (val) == CONSTRUCTOR && !TREE_CLOBBER_P (val) && CONSTRUCTOR_NELTS (val) == 0)) return 0; + if (real_zerop (val)) + { + /* Only return 0 for +0.0, not for -0.0, which doesn't have + an all bytes same memory representation. Don't transform + -0.0 stores into +0.0 even for !HONOR_SIGNED_ZEROS. */ + switch (TREE_CODE (val)) + { + case REAL_CST: + if (!real_isneg (TREE_REAL_CST_PTR (val))) + return 0; + break; + case COMPLEX_CST: + if (!const_with_all_bytes_same (TREE_REALPART (val)) + && !const_with_all_bytes_same (TREE_IMAGPART (val))) + return 0; + break; + case VECTOR_CST: + unsigned int j; + for (j = 0; j < VECTOR_CST_NELTS (val); ++j) + if (const_with_all_bytes_same (VECTOR_CST_ELT (val, i))) + break; + if (j == VECTOR_CST_NELTS (val)) + return 0; + break; + default: + break; + } + } + if (CHAR_BIT != 8 || BITS_PER_UNIT != 8) return -1; |