-mtune=native CPU autodetection for AMD Zen 3 CPU

src/Target.cpp

@@ -62,6 +62,63 @@ static void cpuid(int info[4], int infoType, int extra) {
 #endif
 #endif
 
+#if defined(__x86_64__) || defined(__i386__) || defined(_MSC_VER)
+
+enum class VendorSignatures {
+ UNKNOWN,
+ GENUINE_INTEL,
+ AUTHENTIC_AMD,
+};
+
+VendorSignatures get_vendor_signature() {
+ int info[4];
+ cpuid(info, 0, 0);
+
+ if (info[0] < 1) {
+ return VendorSignatures::UNKNOWN;
+ }
+
+ // "Genu ineI ntel"
+ if (info[1] == 0x756e6547 && info[3] == 0x49656e69 && info[2] == 0x6c65746e) {
+ return VendorSignatures::GENUINE_INTEL;
+ }
+
+ // "Auth enti cAMD"
+ if (info[1] == 0x68747541 && info[3] == 0x69746e65 && info[2] == 0x444d4163) {
+ return VendorSignatures::AUTHENTIC_AMD;
+ }
+
+ return VendorSignatures::UNKNOWN;
+}
+
+void detect_family_and_model(unsigned info0, unsigned &family,
+ unsigned &model) {
+ family = (info0 >> 8) & 0xF; // Bits 8..11
+ model = (info0 >> 4) & 0xF; // Bits 4..7
+ if (family == 0x6 || family == 0xF) {
+ if (family == 0xF) {
+ // Examine extended family ID if family ID is 0xF.
+ family += (info0 >> 20) & 0xFf; // Bits 20..27
+ }
+ // Examine extended model ID if family ID is 0x6 or 0xF.
+ model += ((info0 >> 16) & 0xF) << 4; // Bits 16..19
+ }
+}
+
+Target::Processor get_amd_processor(unsigned family, unsigned model) {
+ switch (family) {
+ case 0x19:
+ // FIXME: do we need to check model number?
+ return Target::Processor::ZnVer3;
+ default:
+ break; // Unknown AMD CPU.
+ }
+
+ return Target::Processor::ProcessorGeneric;
+}
+
+#endif // defined(__x86_64__) || defined(__i386__) || defined(_MSC_VER)
+
 Target calculate_host_target() {
  Target::OS os = Target::OSUnknown;
 #ifdef __linux__
@@ -111,8 +168,18 @@ Target calculate_host_target() {
 #else
  Target::Arch arch = Target::X86;
 
+ VendorSignatures vendor_signature = get_vendor_signature();
+
  int info[4];
  cpuid(info, 1, 0);
+
+ unsigned family = 0, model = 0;
+ detect_family_and_model(info[0], family, model);
+
+ if (vendor_signature == VendorSignatures::AUTHENTIC_AMD) {
+ processor = get_amd_processor(family, model);
+ }
+
  bool have_sse41 = (info[2] & (1 << 19)) != 0;
  bool have_sse2 = (info[3] & (1 << 26)) != 0;
  bool have_avx = (info[2] & (1 << 28)) != 0;
@@ -165,19 +232,23 @@ Target calculate_host_target() {
  }
  if ((info2[1] & avx512) == avx512) {
  initial_features.push_back(Target::AVX512);
+ // FIXME: port to family/model -based detection.
  if ((info2[1] & avx512_knl) == avx512_knl) {
  initial_features.push_back(Target::AVX512_KNL);
  }
+ // FIXME: port to family/model -based detection.
  if ((info2[1] & avx512_skylake) == avx512_skylake) {
  initial_features.push_back(Target::AVX512_Skylake);
  }
+ // FIXME: port to family/model -based detection.
  if ((info2[1] & avx512_cannonlake) == avx512_cannonlake) {
  initial_features.push_back(Target::AVX512_Cannonlake);
 
  const uint32_t avx512vnni = 1U << 11; // vnni result in ecx
  const uint32_t avx512bf16 = 1U << 5; // bf16 result in eax, with cpuid(eax=7, ecx=1)
  int info3[4];
  cpuid(info3, 7, 1);
+ // FIXME: port to family/model -based detection.
  if ((info2[2] & avx512vnni) == avx512vnni &&
  (info3[0] & avx512bf16) == avx512bf16) {
  initial_features.push_back(Target::AVX512_SapphireRapids);