commit 27f8864bd41f0f1b61e8e947d9a030b1a0d23df9
Author: H.J. Lu <hjl.tools@gmail.com>
Date:   Thu Jun 18 05:34:15 2020 -0700

    x86: Update F16C detection [BZ #26133]
    
    Since F16C requires AVX, set F16C usable only when AVX is usable.

diff --git a/sysdeps/x86/cpu-features.c b/sysdeps/x86/cpu-features.c
index 2a801e1856cfe1b3..37619c93f8dbcc5d 100644
--- a/sysdeps/x86/cpu-features.c
+++ b/sysdeps/x86/cpu-features.c
@@ -146,6 +146,10 @@ get_common_indices (struct cpu_features *cpu_features,
 	      if (CPU_FEATURES_CPU_P (cpu_features, XOP))
 		cpu_features->feature[index_arch_XOP_Usable]
 		  |= bit_arch_XOP_Usable;
+	      /* Determine if F16C is usable.  */
+	      if (CPU_FEATURES_CPU_P (cpu_features, F16C))
+		cpu_features->feature[index_arch_F16C_Usable]
+		  |= bit_arch_F16C_Usable;
 	    }
 
 	  /* Check if OPMASK state, upper 256-bit of ZMM0-ZMM15 and
diff --git a/sysdeps/x86/cpu-features.h b/sysdeps/x86/cpu-features.h
index 7abfa046c4b8f6ac..f18f7520fcb7714a 100644
--- a/sysdeps/x86/cpu-features.h
+++ b/sysdeps/x86/cpu-features.h
@@ -142,6 +142,7 @@ extern const struct cpu_features *__get_cpu_features (void)
 #define bit_arch_VPCLMULQDQ_Usable		(1u << 20)
 #define bit_arch_XOP_Usable			(1u << 21)
 #define bit_arch_XSAVEC_Usable			(1u << 22)
+#define bit_arch_F16C_Usable			(1u << 23)
 
 #define index_arch_AVX_Usable			FEATURE_INDEX_1
 #define index_arch_AVX2_Usable			FEATURE_INDEX_1
@@ -166,6 +167,7 @@ extern const struct cpu_features *__get_cpu_features (void)
 #define index_arch_VPCLMULQDQ_Usable		FEATURE_INDEX_1
 #define index_arch_XOP_Usable			FEATURE_INDEX_1
 #define index_arch_XSAVEC_Usable		FEATURE_INDEX_1
+#define index_arch_F16C_Usable			FEATURE_INDEX_1
 
 /* Unused.  Compiler will optimize them out.  */
 #define bit_arch_SSE3_Usable			(1u << 0)
@@ -179,7 +181,6 @@ extern const struct cpu_features *__get_cpu_features (void)
 #define bit_arch_AES_Usable			(1u << 0)
 #define bit_arch_XSAVE_Usable			(1u << 0)
 #define bit_arch_OSXSAVE_Usable			(1u << 0)
-#define bit_arch_F16C_Usable			(1u << 0)
 #define bit_arch_RDRAND_Usable			(1u << 0)
 #define bit_arch_FPU_Usable			(1u << 0)
 #define bit_arch_TSC_Usable			(1u << 0)
@@ -236,7 +237,6 @@ extern const struct cpu_features *__get_cpu_features (void)
 #define index_arch_AES_Usable			FEATURE_INDEX_1
 #define index_arch_XSAVE_Usable			FEATURE_INDEX_1
 #define index_arch_OSXSAVE_Usable		FEATURE_INDEX_1
-#define index_arch_F16C_Usable			FEATURE_INDEX_1
 #define index_arch_RDRAND_Usable		FEATURE_INDEX_1
 #define index_arch_FPU_Usable			FEATURE_INDEX_1
 #define index_arch_TSC_Usable			FEATURE_INDEX_1
@@ -296,7 +296,7 @@ extern const struct cpu_features *__get_cpu_features (void)
 #define need_arch_feature_XSAVE			0
 #define need_arch_feature_OSXSAVE		0
 #define need_arch_feature_AVX			1
-#define need_arch_feature_F16C			0
+#define need_arch_feature_F16C			1
 #define need_arch_feature_RDRAND		0
 
 /* EDX.  */