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| author | H.J. Lu <hjl.tools@gmail.com> | 2017-09-12 07:46:11 -0700 |
|---|---|---|
| committer | H.J. Lu <hjl.tools@gmail.com> | 2017-09-12 07:54:47 -0700 |
| commit | ef8adeb0416309082c41a1518caee6961b5c42e8 (patch) | |
| tree | 1907bd459f82a962252cc5852bbee9025b3a99ad /sysdeps | |
| parent | a166531fdf601560a0005479427f60d3173f8257 (diff) | |
| download | glibc-ef8adeb0416309082c41a1518caee6961b5c42e8.tar.gz glibc-ef8adeb0416309082c41a1518caee6961b5c42e8.tar.xz glibc-ef8adeb0416309082c41a1518caee6961b5c42e8.zip | |
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')
| -rw-r--r-- | sysdeps/x86/cpu-features.h | 2 | ||||
| -rw-r--r-- | sysdeps/x86/cpu-tunables.c | 7 | ||||
| -rw-r--r-- | sysdeps/x86_64/fpu/multiarch/ifunc-mathvec-avx512.h | 13 |
3 files changed, 17 insertions, 5 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__ */ diff --git a/sysdeps/x86/cpu-tunables.c b/sysdeps/x86/cpu-tunables.c index 0ab708cca8..ec72d86f08 100644 --- a/sysdeps/x86/cpu-tunables.c +++ b/sysdeps/x86/cpu-tunables.c @@ -303,6 +303,13 @@ TUNABLE_CALLBACK (set_hwcaps) (tunable_val_t *valp) disable, 23); } break; + case 24: + { + CHECK_GLIBC_IFUNC_ARCH_NEED_ARCH_BOTH + (n, cpu_features, MathVec_Prefer_No_AVX512, + AVX512F_Usable, disable, 24); + } + break; case 26: { CHECK_GLIBC_IFUNC_ARCH_NEED_CPU_BOTH diff --git a/sysdeps/x86_64/fpu/multiarch/ifunc-mathvec-avx512.h b/sysdeps/x86_64/fpu/multiarch/ifunc-mathvec-avx512.h index 1857e1f760..fffc9da114 100644 --- a/sysdeps/x86_64/fpu/multiarch/ifunc-mathvec-avx512.h +++ b/sysdeps/x86_64/fpu/multiarch/ifunc-mathvec-avx512.h @@ -32,11 +32,14 @@ IFUNC_SELECTOR (void) { const struct cpu_features* cpu_features = __get_cpu_features (); - if (CPU_FEATURES_ARCH_P (cpu_features, AVX512DQ_Usable)) - return OPTIMIZE (skx); - - if (CPU_FEATURES_ARCH_P (cpu_features, AVX512F_Usable)) - return OPTIMIZE (knl); + if (!CPU_FEATURES_ARCH_P (cpu_features, MathVec_Prefer_No_AVX512)) + { + if (CPU_FEATURES_ARCH_P (cpu_features, AVX512DQ_Usable)) + return OPTIMIZE (skx); + + if (CPU_FEATURES_ARCH_P (cpu_features, AVX512F_Usable)) + return OPTIMIZE (knl); + } return OPTIMIZE (avx2_wrapper); } |