[PATCH] x86-64: Check FMA_Usable in ifunc-mathvec-avx2.h [BZ #21966]

[H.J. Lu]

Since the AVX2 version of mathvec functions uses FMA, it can only be
used when FMA is usable.

Any comments?

Andrew, please take a look and check if it should be fixed on branches.

Thanks.

H.J.
	[BZ #21966]
	* sysdeps/x86_64/fpu/multiarch/ifunc-mathvec-avx2.h
	(IFUNC_SELECTOR): Don't use the AVX2 version if FMA isn't
	usable.
---
 sysdeps/x86_64/fpu/multiarch/ifunc-mathvec-avx2.h | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/sysdeps/x86_64/fpu/multiarch/ifunc-mathvec-avx2.h b/sysdeps/x86_64/fpu/multiarch/ifunc-mathvec-avx2.h
index a43d4c54fa..ccda2748c5 100644
--- a/sysdeps/x86_64/fpu/multiarch/ifunc-mathvec-avx2.h
+++ b/sysdeps/x86_64/fpu/multiarch/ifunc-mathvec-avx2.h
@@ -31,7 +31,8 @@ IFUNC_SELECTOR (void)
 {
   const struct cpu_features* cpu_features = __get_cpu_features ();
 
-  if (CPU_FEATURES_ARCH_P (cpu_features, AVX2_Usable))
+  if (CPU_FEATURES_ARCH_P (cpu_features, FMA_Usable)
+      && CPU_FEATURES_ARCH_P (cpu_features, AVX2_Usable))
     return OPTIMIZE (avx2);
 
   return OPTIMIZE (sse_wrapper);
-- 
2.13.5