1/* 2 * Copyright (c) 2011 The WebRTC project authors. All Rights Reserved. 3 * 4 * Use of this source code is governed by a BSD-style license 5 * that can be found in the LICENSE file in the root of the source 6 * tree. An additional intellectual property rights grant can be found 7 * in the file PATENTS. All contributing project authors may 8 * be found in the AUTHORS file in the root of the source tree. 9 */ 10 11// Parts of this file derived from Chromium's base/cpu.cc. 12 13#include "webrtc/system_wrappers/include/cpu_features_wrapper.h" 14 15#if defined(WEBRTC_ARCH_X86_FAMILY) && defined(_MSC_VER) 16#include <intrin.h> 17#endif 18 19#include "webrtc/typedefs.h" 20 21// No CPU feature is available => straight C path. 22int GetCPUInfoNoASM(CPUFeature feature) { 23 (void)feature; 24 return 0; 25} 26 27#if defined(WEBRTC_ARCH_X86_FAMILY) 28#ifndef _MSC_VER 29// Intrinsic for "cpuid". 30#if defined(__pic__) && defined(__i386__) 31static inline void __cpuid(int cpu_info[4], int info_type) { 32 __asm__ volatile( 33 "mov %%ebx, %%edi\n" 34 "cpuid\n" 35 "xchg %%edi, %%ebx\n" 36 : "=a"(cpu_info[0]), "=D"(cpu_info[1]), "=c"(cpu_info[2]), "=d"(cpu_info[3]) 37 : "a"(info_type)); 38} 39#else 40static inline void __cpuid(int cpu_info[4], int info_type) { 41 __asm__ volatile( 42 "cpuid\n" 43 : "=a"(cpu_info[0]), "=b"(cpu_info[1]), "=c"(cpu_info[2]), "=d"(cpu_info[3]) 44 : "a"(info_type)); 45} 46#endif 47#endif // _MSC_VER 48#endif // WEBRTC_ARCH_X86_FAMILY 49 50#if defined(WEBRTC_ARCH_X86_FAMILY) 51// Actual feature detection for x86. 52static int GetCPUInfo(CPUFeature feature) { 53 int cpu_info[4]; 54 __cpuid(cpu_info, 1); 55 if (feature == kSSE2) { 56 return 0 != (cpu_info[3] & 0x04000000); 57 } 58 if (feature == kSSE3) { 59 return 0 != (cpu_info[2] & 0x00000001); 60 } 61 return 0; 62} 63#else 64// Default to straight C for other platforms. 65static int GetCPUInfo(CPUFeature feature) { 66 (void)feature; 67 return 0; 68} 69#endif 70 71WebRtc_CPUInfo WebRtc_GetCPUInfo = GetCPUInfo; 72WebRtc_CPUInfo WebRtc_GetCPUInfoNoASM = GetCPUInfoNoASM; 73