From 51df2605064a2bfd44fa0655ef9815812347de80 Mon Sep 17 00:00:00 2001 From: Joseph Myers Date: Thu, 24 Sep 2015 16:48:32 +0000 Subject: [PATCH] Fix x86_64 fma4 pow inappropriate contraction (bug 19003). The x86_64 fma4 version of pow fails to disable contraction of operations other than those explicitly intended to use fma instructions, so resulting in large ulps errors on processors with fma4 instructions, as in bug 18104 (165ulp for the test added for that bug; error originally reported by "blaaa" on #glibc). This patch adds $(config-cflags-nofma) for e_pow-fma4.c, corresponding to the use for e_pow.c in sysdeps/ieee754/dbl-64/Makefile. Tested for x86_64 on a processor with fma4. [BZ #19003] * sysdeps/x86_64/fpu/multiarch/Makefile (CFLAGS-e_pow-fma4.c): Add $(config-cflags-nofma). --- ChangeLog | 6 ++++++ NEWS | 2 +- sysdeps/x86_64/fpu/multiarch/Makefile | 2 +- 3 files changed, 8 insertions(+), 2 deletions(-) diff --git a/ChangeLog b/ChangeLog index c900f20e89..df079ca412 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,9 @@ +2015-09-24 Joseph Myers + + [BZ #19003] + * sysdeps/x86_64/fpu/multiarch/Makefile (CFLAGS-e_pow-fma4.c): Add + $(config-cflags-nofma). + 2015-09-24 Szabolcs Nagy * sysdeps/aarch64/libm-test-ulps: Regenerated. diff --git a/NEWS b/NEWS index bf16f4f8ba..b06a826521 100644 --- a/NEWS +++ b/NEWS @@ -16,7 +16,7 @@ Version 2.23 18647, 18661, 18674, 18675, 18681, 18757, 18778, 18781, 18787, 18789, 18790, 18795, 18796, 18820, 18823, 18824, 18857, 18863, 18870, 18872, 18873, 18875, 18887, 18921, 18951, 18952, 18961, 18966, 18967, 18970, - 18977, 18980, 18981. + 18977, 18980, 18981, 19003. * The obsolete header has been removed. Programs that require this header must be updated to use instead. diff --git a/sysdeps/x86_64/fpu/multiarch/Makefile b/sysdeps/x86_64/fpu/multiarch/Makefile index 86ea473b4f..631534a5ce 100644 --- a/sysdeps/x86_64/fpu/multiarch/Makefile +++ b/sysdeps/x86_64/fpu/multiarch/Makefile @@ -16,7 +16,7 @@ CFLAGS-e_asin-fma4.c = -mfma4 CFLAGS-e_atan2-fma4.c = -mfma4 CFLAGS-e_exp-fma4.c = -mfma4 CFLAGS-e_log-fma4.c = -mfma4 -CFLAGS-e_pow-fma4.c = -mfma4 +CFLAGS-e_pow-fma4.c = -mfma4 $(config-cflags-nofma) CFLAGS-halfulp-fma4.c = -mfma4 CFLAGS-mpa-fma4.c = -mfma4 CFLAGS-mpatan-fma4.c = -mfma4