src/impl_x86_windows.c

// 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_WINDOWS

#include "impl_x86__base_implementation.inl"

static void OverrideOsPreserves(OsPreserves* os_preserves) {
  (void)os_preserves;
  // No override
}

#include "internal/windows_utils.h"

#if defined(CPU_FEATURES_MOCK_CPUID_X86)
extern bool GetWindowsIsProcessorFeaturePresent(DWORD);
#else  // CPU_FEATURES_MOCK_CPUID_X86
static bool GetWindowsIsProcessorFeaturePresent(DWORD ProcessorFeature) {
  return IsProcessorFeaturePresent(ProcessorFeature);
}
#endif

static void DetectFeaturesFromOs(X86Info* info, X86Features* features) {
  // Handling Windows platform through IsProcessorFeaturePresent.
  // https://docs.microsoft.com/en-us/windows/win32/api/processthreadsapi/nf-processthreadsapi-isprocessorfeaturepresent
  features->sse =
      GetWindowsIsProcessorFeaturePresent(PF_XMMI_INSTRUCTIONS_AVAILABLE);
  features->sse2 =
      GetWindowsIsProcessorFeaturePresent(PF_XMMI64_INSTRUCTIONS_AVAILABLE);
  features->sse3 =
      GetWindowsIsProcessorFeaturePresent(PF_SSE3_INSTRUCTIONS_AVAILABLE);
  features->ssse3 =
      GetWindowsIsProcessorFeaturePresent(PF_SSSE3_INSTRUCTIONS_AVAILABLE);
  features->sse4_1 =
      GetWindowsIsProcessorFeaturePresent(PF_SSE4_1_INSTRUCTIONS_AVAILABLE);
  features->sse4_2 =
      GetWindowsIsProcessorFeaturePresent(PF_SSE4_2_INSTRUCTIONS_AVAILABLE);

// do not bother checking PF_AVX*
// cause AVX enabled processor will have XCR0 be exposed and this function will be skipped at all
}

#endif  // CPU_FEATURES_OS_WINDOWS
#endif  // CPU_FEATURES_ARCH_X86