[PATCH] x86: Update F16C detection [BZ #26133]

H.J. Lu hjl.tools@gmail.com
Thu Jun 18 13:20:12 GMT 2020


Since F16C requires AVX, set F16C usable only when AVX is usable.
---
 sysdeps/x86/cpu-features.c | 4 ++++
 sysdeps/x86/cpu-features.h | 6 +++---
 2 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/sysdeps/x86/cpu-features.c b/sysdeps/x86/cpu-features.c
index 489c370348..f873b55e8d 100644
--- a/sysdeps/x86/cpu-features.c
+++ b/sysdeps/x86/cpu-features.c
@@ -153,6 +153,10 @@ 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 de20044417..969c61773f 100644
--- a/sysdeps/x86/cpu-features.h
+++ b/sysdeps/x86/cpu-features.h
@@ -145,6 +145,7 @@ extern const struct cpu_features *__get_cpu_features (void)
 #define bit_arch_XSAVEC_Usable			(1u << 22)
 #define bit_arch_AVX512_VP2INTERSECT_Usable	(1u << 23)
 #define bit_arch_AVX512_BF16_Usable		(1u << 24)
+#define bit_arch_F16C_Usable			(1u << 25)
 
 #define index_arch_AVX_Usable			FEATURE_INDEX_1
 #define index_arch_AVX2_Usable			FEATURE_INDEX_1
@@ -171,6 +172,7 @@ extern const struct cpu_features *__get_cpu_features (void)
 #define index_arch_XSAVEC_Usable		FEATURE_INDEX_1
 #define index_arch_AVX512_VP2INTERSECT_Usable	FEATURE_INDEX_1
 #define index_arch_AVX512_BF16_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)
@@ -184,7 +186,6 @@ 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)
@@ -241,7 +242,6 @@ 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
@@ -301,7 +301,7 @@ 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.  */
-- 
2.26.2



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