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authorH.J. Lu <hjl.tools@gmail.com>2017-09-12 07:46:11 -0700
committerH.J. Lu <hjl.tools@gmail.com>2017-09-12 07:54:47 -0700
commitef8adeb0416309082c41a1518caee6961b5c42e8 (patch)
tree1907bd459f82a962252cc5852bbee9025b3a99ad /sysdeps/x86/cpu-features.h
parenta166531fdf601560a0005479427f60d3173f8257 (diff)
x86: Add MathVec_Prefer_No_AVX512 to cpu-features [BZ #21967]
AVX512 functions in mathvec are used on machines with AVX512. An AVX2 wrapper is also provided and it can be used when the AVX512 version isn't profitable. MathVec_Prefer_No_AVX512 is addded to cpu-features. If glibc.tune.hwcaps=MathVec_Prefer_No_AVX512 is set in GLIBC_TUNABLES environment variable, the AVX2 wrapper will be used. Tested on x86-64 machines with and without AVX512. Also verified glibc.tune.hwcaps=MathVec_Prefer_No_AVX512 on AVX512 machine. [BZ #21967] * sysdeps/x86/cpu-features.h (bit_arch_MathVec_Prefer_No_AVX512): New. (index_arch_MathVec_Prefer_No_AVX512): Likewise. * sysdeps/x86/cpu-tunables.c (TUNABLE_CALLBACK (set_hwcaps)): Handle MathVec_Prefer_No_AVX512. * sysdeps/x86_64/fpu/multiarch/ifunc-mathvec-avx512.h (IFUNC_SELECTOR): Return AVX2 version if MathVec_Prefer_No_AVX512 is set.
Diffstat (limited to 'sysdeps/x86/cpu-features.h')
-rw-r--r--sysdeps/x86/cpu-features.h2
1 files changed, 2 insertions, 0 deletions
diff --git a/sysdeps/x86/cpu-features.h b/sysdeps/x86/cpu-features.h
index 9e01781424..a032a2e168 100644
--- a/sysdeps/x86/cpu-features.h
+++ b/sysdeps/x86/cpu-features.h
@@ -40,6 +40,7 @@
#define bit_arch_Use_dl_runtime_resolve_opt (1 << 20)
#define bit_arch_Use_dl_runtime_resolve_slow (1 << 21)
#define bit_arch_Prefer_No_AVX512 (1 << 22)
+#define bit_arch_MathVec_Prefer_No_AVX512 (1 << 23)
/* CPUID Feature flags. */
@@ -239,6 +240,7 @@ extern const struct cpu_features *__get_cpu_features (void)
# define index_arch_Use_dl_runtime_resolve_opt FEATURE_INDEX_1
# define index_arch_Use_dl_runtime_resolve_slow FEATURE_INDEX_1
# define index_arch_Prefer_No_AVX512 FEATURE_INDEX_1
+# define index_arch_MathVec_Prefer_No_AVX512 FEATURE_INDEX_1
#endif /* !__ASSEMBLER__ */