61 lines
1.7 KiB
C++
61 lines
1.7 KiB
C++
/*
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* Copyright (c) 2011 The WebRTC project authors. All Rights Reserved.
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*
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* Use of this source code is governed by a BSD-style license
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* that can be found in the LICENSE file in the root of the source
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* tree. An additional intellectual property rights grant can be found
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* in the file PATENTS. All contributing project authors may
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* be found in the AUTHORS file in the root of the source tree.
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*/
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#include "cpu_features_wrapper.h"
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// No CPU feature is available => straight C path.
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int GetCPUInfoNoASM(CPUFeature feature) {
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(void)feature;
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return 0;
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}
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// Intrinsic for "cpuid".
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#if defined(__pic__) && defined(__i386__)
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static inline void cpuid(int cpu_info[4], int info_type) {
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__asm__ volatile (
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"mov %%ebx, %%edi\n"
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"cpuid\n"
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"xchg %%edi, %%ebx\n"
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: "=a"(cpu_info[0]), "=D"(cpu_info[1]), "=c"(cpu_info[2]), "=d"(cpu_info[3])
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: "a"(info_type));
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}
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#elif defined(__i386__) || defined(__x86_64__)
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static inline void cpuid(int cpu_info[4], int info_type) {
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__asm__ volatile (
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"cpuid\n"
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: "=a"(cpu_info[0]), "=b"(cpu_info[1]), "=c"(cpu_info[2]), "=d"(cpu_info[3])
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: "a"(info_type));
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}
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#endif
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#if defined(__i386__) || defined(__x86_64__)
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// Actual feature detection for x86.
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static int GetCPUInfo(CPUFeature feature) {
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int cpu_info[4];
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cpuid(cpu_info, 1);
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if (feature == kSSE2) {
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return 0 != (cpu_info[3] & 0x04000000);
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}
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if (feature == kSSE3) {
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return 0 != (cpu_info[2] & 0x00000001);
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}
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return 0;
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}
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#else
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// Default to straight C for other platforms.
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static int GetCPUInfo(CPUFeature feature) {
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(void)feature;
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return 0;
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}
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#endif
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WebRtc_CPUInfo WebRtc_GetCPUInfo = GetCPUInfo;
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WebRtc_CPUInfo WebRtc_GetCPUInfoNoASM = GetCPUInfoNoASM;
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