x86: Don't set Prefer_No_AVX512 for processors with AVX512 and AVX-VNNI

Don't set Prefer_No_AVX512 on processors with AVX512 and AVX-VNNI since
they won't lower CPU frequency when ZMM load and store instructions are
used.

(cherry picked from commit ceeffe968c01b1202e482f4855cb6baf5c6cb713)

diff --git a/sysdeps/x86/cpu-features.c b/sysdeps/x86/cpu-features.c
index e7dc25aaf534eb89f263b861b770e4f38fc21c14..42b02d1d339a99883ddb92993cf4139fe2cb2bf2 100644 (file)
--- a/sysdeps/x86/cpu-features.c
+++ b/sysdeps/x86/cpu-features.c
@@ -555,8 +555,11 @@ disable_tsx:
          |= bit_arch_Prefer_No_VZEROUPPER;
       else
        {
-         cpu_features->preferred[index_arch_Prefer_No_AVX512]
-           |= bit_arch_Prefer_No_AVX512;
+         /* Processors with AVX512 and AVX-VNNI won't lower CPU frequency
+            when ZMM load and store instructions are used.  */
+         if (!CPU_FEATURES_CPU_P (cpu_features, AVX_VNNI))
+           cpu_features->preferred[index_arch_Prefer_No_AVX512]
+             |= bit_arch_Prefer_No_AVX512;
 
          /* Avoid RTM abort triggered by VZEROUPPER inside a
             transactionally executing RTM region.  */