1 files changed, 57 insertions, 0 deletions
diff --git a/src/impl_x86_macos.c b/src/impl_x86_macos.c
new file mode 100644
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--- /dev/null
+++ b/src/impl_x86_macos.c
@@ -0,0 +1,57 @@
+// Copyright 2017 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//    http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "cpu_features_macros.h"
+
+#ifdef CPU_FEATURES_ARCH_X86
+#ifdef CPU_FEATURES_OS_MACOS
+
+#include "impl_x86__base_implementation.inl"
+
+#if !defined(HAVE_SYSCTLBYNAME)
+#error "Darwin needs support for sysctlbyname"
+#endif
+#include <sys/sysctl.h>
+
+#if defined(CPU_FEATURES_MOCK_CPUID_X86)
+extern bool GetDarwinSysCtlByName(const char*);
+#else  // CPU_FEATURES_MOCK_CPUID_X86
+static bool GetDarwinSysCtlByName(const char* name) {
+  int enabled;
+  size_t enabled_len = sizeof(enabled);
+  const int failure = sysctlbyname(name, &enabled, &enabled_len, NULL, 0);
+  return failure ? false : enabled;
+}
+#endif
+
+static void OverrideOsPreserves(OsPreserves* os_preserves) {
+  // On Darwin AVX512 support is On-demand.
+  // We have to query the OS instead of querying the Zmm save/restore state.
+  // https://github.com/apple/darwin-xnu/blob/8f02f2a044b9bb1ad951987ef5bab20ec9486310/osfmk/i386/fpu.c#L173-L199
+  os_preserves->avx512_registers = GetDarwinSysCtlByName("hw.optional.avx512f");
+}
+
+static void DetectFeaturesFromOs(X86Info* info, X86Features* features) {
+  (void)info;
+  // Handling Darwin platform through sysctlbyname.
+  features->sse = GetDarwinSysCtlByName("hw.optional.sse");
+  features->sse2 = GetDarwinSysCtlByName("hw.optional.sse2");
+  features->sse3 = GetDarwinSysCtlByName("hw.optional.sse3");
+  features->ssse3 = GetDarwinSysCtlByName("hw.optional.supplementalsse3");
+  features->sse4_1 = GetDarwinSysCtlByName("hw.optional.sse4_1");
+  features->sse4_2 = GetDarwinSysCtlByName("hw.optional.sse4_2");
+}
+
+#endif  // CPU_FEATURES_OS_MACOS
+#endif  // CPU_FEATURES_ARCH_X86