git-svn-id: http://webrtc.googlecode.com/svn/trunk@6 4adac7df-926f-26a2-2b94-8c16560cd09d
diff --git a/system_wrappers/source/cpu_features.cc b/system_wrappers/source/cpu_features.cc
new file mode 100644
index 0000000..850dc9b
--- /dev/null
+++ b/system_wrappers/source/cpu_features.cc
@@ -0,0 +1,60 @@
+/*
+ * 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.
+ */
+
+#include "cpu_features_wrapper.h"
+
+// No CPU feature is available => straight C path.
+int GetCPUInfoNoASM(CPUFeature feature) {
+ (void)feature;
+ return 0;
+}
+
+// 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));
+}
+#elif defined(__i386__) || defined(__x86_64__)
+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
+
+#if defined(__i386__) || defined(__x86_64__)
+// 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;