Detect AVX512-FP16 extension

Author: Maratyszcza

include/cpuinfo.h

@@ -740,6 +740,7 @@ void CPUINFO_ABI cpuinfo_deinitialize(void);
 		bool avx512vpopcntdq;
 		bool avx512vnni;
 		bool avx512bf16;
+		bool avx512fp16;
 		bool avx512vp2intersect;
 		bool avx512_4vnniw;
 		bool avx512_4fmaps;
@@ -1219,6 +1220,14 @@ static inline bool cpuinfo_has_x86_avx512bf16(void) {
 	#endif
 }
 
+static inline bool cpuinfo_has_x86_avx512fp16(void) {
+	#if CPUINFO_ARCH_X86 || CPUINFO_ARCH_X86_64
+		return cpuinfo_isa.avx512fp16;
+	#else
+		return false;
+	#endif
+}
+
 static inline bool cpuinfo_has_x86_avx512vp2intersect(void) {
 	#if CPUINFO_ARCH_X86 || CPUINFO_ARCH_X86_64
 		return cpuinfo_isa.avx512vp2intersect;

src/x86/isa.c

@@ -490,6 +490,12 @@ struct cpuinfo_x86_isa cpuinfo_x86_detect_isa(
 	 */
 	isa.avx512vp2intersect = avx512_regs && !!(structured_feature_info0.edx & UINT32_C(0x00000100));
 
+	/*
+	 * AVX512_FP16 instructions:
+	 * - Intel: edx[bit 23] in structured feature info (ecx = 0).
+	 */
+	isa.avx512fp16 = avx512_regs && !!(structured_feature_info0.edx & UINT32_C(0x00800000));
+
 	/*
 	 * AVX512_BF16 instructions:
 	 * - Intel: eax[bit 5] in structured feature info (ecx = 1).

tools/isa-info.c

@@ -68,6 +68,7 @@ int main(int argc, char** argv) {
 		printf("\tAVX512VPOPCNTDQ: %s\n", cpuinfo_has_x86_avx512vpopcntdq() ? "yes" : "no");
 		printf("\tAVX512VNNI: %s\n", cpuinfo_has_x86_avx512vnni() ? "yes" : "no");
 		printf("\tAVX512BF16: %s\n", cpuinfo_has_x86_avx512bf16() ? "yes" : "no");
+		printf("\tAVX512FP16: %s\n", cpuinfo_has_x86_avx512fp16() ? "yes" : "no");
 		printf("\tAVX512VP2INTERSECT: %s\n", cpuinfo_has_x86_avx512vp2intersect() ? "yes" : "no");
 		printf("\tAVX512_4VNNIW: %s\n", cpuinfo_has_x86_avx512_4vnniw() ? "yes" : "no");
 		printf("\tAVX512_4FMAPS: %s\n", cpuinfo_has_x86_avx512_4fmaps() ? "yes" : "no");