From 9e207d6fec83ee36458d59254d3fd40b3752bec2 Mon Sep 17 00:00:00 2001 From: Jakub Jelinek Date: Tue, 9 Aug 2016 09:49:14 +0200 Subject: [PATCH] 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 --- gcc/ChangeLog | 6 ++++ gcc/testsuite/ChangeLog | 5 ++++ .../gcc.c-torture/execute/ieee/pr72824.c | 19 ++++++++++++ gcc/tree-loop-distribution.c | 30 ++++++++++++++++++- 4 files changed, 59 insertions(+), 1 deletion(-) create mode 100644 gcc/testsuite/gcc.c-torture/execute/ieee/pr72824.c diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 2d96f88466a..e71b548253e 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,9 @@ +2016-08-09 Jakub Jelinek + + PR tree-optimization/72824 + * tree-loop-distribution.c (const_with_all_bytes_same): Verify + real_zerop is not negative. + 2016-08-09 Richard Biener PR tree-optimization/71802 diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index 9ba1052e768..711778bfb8e 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2016-08-09 Jakub Jelinek + + PR tree-optimization/72824 + * gcc.c-torture/execute/ieee/pr72824.c: New test. + 2016-08-09 Richard Biener PR tree-optimization/71802 diff --git a/gcc/testsuite/gcc.c-torture/execute/ieee/pr72824.c b/gcc/testsuite/gcc.c-torture/execute/ieee/pr72824.c new file mode 100644 index 00000000000..1c213733ca1 --- /dev/null +++ b/gcc/testsuite/gcc.c-torture/execute/ieee/pr72824.c @@ -0,0 +1,19 @@ +/* PR tree-optimization/72824 */ + +static inline void +foo (float *x, float value) +{ + int i; + for (i = 0; i < 32; ++i) + x[i] = value; +} + +int +main () +{ + float x[32]; + foo (x, -0.f); + if (__builtin_copysignf (1.0, x[3]) != -1.0f) + __builtin_abort (); + return 0; +} diff --git a/gcc/tree-loop-distribution.c b/gcc/tree-loop-distribution.c index 181e4e9ed7d..342b9647fe7 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; -- 2.30.2