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Diffstat (limited to 'sysdeps/x86/cpu-features.c')
-rw-r--r--sysdeps/x86/cpu-features.c6
1 files changed, 5 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. */