1 files changed, 74 insertions, 0 deletions
diff --git a/src/system_wrappers/source/cpu_features.cc b/src/system_wrappers/source/cpu_features.cc
new file mode 100644
index 0000000..41a86e3
--- /dev/null
+++ b/src/system_wrappers/source/cpu_features.cc
@@ -0,0 +1,74 @@
+/*
+ *  Copyright (c) 2011 The WebRTC project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+// Parts of this file derived from Chromium's base/cpu.cc.
+
+#include "cpu_features_wrapper.h"
+
+#include "typedefs.h"
+
+#if defined(WEBRTC_ARCH_X86_FAMILY)
+#if defined(_MSC_VER)
+#include <intrin.h>
+#endif
+#endif
+
+// No CPU feature is available => straight C path.
+int GetCPUInfoNoASM(CPUFeature feature) {
+  (void)feature;
+  return 0;
+}
+
+#if defined(WEBRTC_ARCH_X86_FAMILY)
+#ifndef _MSC_VER
+// Intrinsic for "cpuid".
+#if defined(__pic__) && defined(__i386__)
+static inline void __cpuid(int cpu_info[4], int info_type) {
+  __asm__ volatile (
+    "mov %%ebx, %%edi\n"
+    "cpuid\n"
+    "xchg %%edi, %%ebx\n"
+    : "=a"(cpu_info[0]), "=D"(cpu_info[1]), "=c"(cpu_info[2]), "=d"(cpu_info[3])
+    : "a"(info_type));
+}
+#else
+static inline void __cpuid(int cpu_info[4], int info_type) {
+  __asm__ volatile (
+    "cpuid\n"
+    : "=a"(cpu_info[0]), "=b"(cpu_info[1]), "=c"(cpu_info[2]), "=d"(cpu_info[3])
+    : "a"(info_type));
+}
+#endif
+#endif  // _MSC_VER
+#endif  // WEBRTC_ARCH_X86_FAMILY
+
+#if defined(WEBRTC_ARCH_X86_FAMILY)
+// Actual feature detection for x86.
+static int GetCPUInfo(CPUFeature feature) {
+  int cpu_info[4];
+  __cpuid(cpu_info, 1);
+  if (feature == kSSE2) {
+    return 0 != (cpu_info[3] & 0x04000000);
+  }
+  if (feature == kSSE3) {
+    return 0 != (cpu_info[2] & 0x00000001);
+  }
+  return 0;
+}
+#else
+// Default to straight C for other platforms.
+static int GetCPUInfo(CPUFeature feature) {
+  (void)feature;
+  return 0;
+}
+#endif
+
+WebRtc_CPUInfo WebRtc_GetCPUInfo = GetCPUInfo;
+WebRtc_CPUInfo WebRtc_GetCPUInfoNoASM = GetCPUInfoNoASM;