diff options
Diffstat (limited to 'sysdeps/x86')
| -rw-r--r-- | sysdeps/x86/cpu-features.c | 6 | ||||
| -rw-r--r-- | sysdeps/x86/cpu-features.h | 3 |
2 files changed, 8 insertions, 1 deletions
diff --git a/sysdeps/x86/cpu-features.c b/sysdeps/x86/cpu-features.c index ae7f844f8b..f30918dd3b 100644 --- a/sysdeps/x86/cpu-features.c +++ b/sysdeps/x86/cpu-features.c @@ -224,10 +224,14 @@ init_cpu_features (struct cpu_features *cpu_features) |= bit_arch_AVX_Fast_Unaligned_Load; /* Since AVX512ER is unique to Xeon Phi, set Prefer_No_VZEROUPPER - if AVX512ER is available. */ + if AVX512ER is available. Don't use AVX512 to avoid lower CPU + frequency if AVX512ER isn't available. */ if (CPU_FEATURES_CPU_P (cpu_features, AVX512ER)) cpu_features->feature[index_arch_Prefer_No_VZEROUPPER] |= bit_arch_Prefer_No_VZEROUPPER; + else + cpu_features->feature[index_arch_Prefer_No_AVX512] + |= bit_arch_Prefer_No_AVX512; /* To avoid SSE transition penalty, use _dl_runtime_resolve_slow. If XGETBV suports ECX == 1, use _dl_runtime_resolve_opt. */ diff --git a/sysdeps/x86/cpu-features.h b/sysdeps/x86/cpu-features.h index 1583d65345..85a39e7d70 100644 --- a/sysdeps/x86/cpu-features.h +++ b/sysdeps/x86/cpu-features.h @@ -39,6 +39,7 @@ #define bit_arch_Prefer_ERMS (1 << 19) #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) /* CPUID Feature flags. */ @@ -118,6 +119,7 @@ # define index_arch_Prefer_ERMS FEATURE_INDEX_1*FEATURE_SIZE # define index_arch_Use_dl_runtime_resolve_opt FEATURE_INDEX_1*FEATURE_SIZE # define index_arch_Use_dl_runtime_resolve_slow FEATURE_INDEX_1*FEATURE_SIZE +# define index_arch_Prefer_No_AVX512 FEATURE_INDEX_1*FEATURE_SIZE # if defined (_LIBC) && !IS_IN (nonlib) @@ -302,6 +304,7 @@ extern const struct cpu_features *__get_cpu_features (void) # define index_arch_Prefer_ERMS FEATURE_INDEX_1 # 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 #endif /* !__ASSEMBLER__ */ |