libyuv/source/cpu_id.cc
fbarchard@google.com 4ae6b46ce1 Add SSE42 and AVX detect
BUG=none
TEST=libyuvTest.TestCpuHas
Review URL: https://webrtc-codereview.appspot.com/607006

git-svn-id: http://libyuv.googlecode.com/svn/trunk@271 16f28f9a-4ce2-e073-06de-1de4eb20be90
2012-05-30 03:02:52 +00:00

132 lines
3.8 KiB
C++

/*
* Copyright (c) 2011 The LibYuv 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 "libyuv/cpu_id.h"
#ifdef _MSC_VER
#include <intrin.h> // For __cpuid()
#endif
#include <stdlib.h> // For getenv()
// For ArmCpuCaps() but unittested on all platforms
#include <stdio.h>
#include <string.h>
#include "libyuv/basic_types.h" // For CPU_X86
// TODO(fbarchard): Use cpuid.h when gcc 4.4 is used on OSX and Linux.
#if (defined(__pic__) || defined(__APPLE__)) && 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
#ifdef __cplusplus
namespace libyuv {
extern "C" {
#endif
// Low level cpuid for X86. Returns zeros on other CPUs.
void CpuId(int cpu_info[4], int info_type) {
#if defined(__i386__) || defined(__x86_64__) || \
defined(_M_IX86) || defined(_M_X64)
__cpuid(cpu_info, info_type);
#else
cpu_info[0] = cpu_info[1] = cpu_info[2] = cpu_info[3] = 0;
#endif
}
// based on libvpx arm_cpudetect.c
// For Arm, but testable on any CPU
int ArmCpuCaps(const char* cpuinfoname) {
int flags = 0;
FILE* fin = fopen(cpuinfoname, "r");
if (fin) {
char buf[512];
while (fgets(buf, 511, fin)) {
if (memcmp(buf, "Features", 8) == 0) {
char* p = strstr(buf, " neon");
if (p && (p[5] == ' ' || p[5] == '\n')) {
flags |= kCpuHasNEON;
break;
}
}
}
fclose(fin);
}
return flags;
}
// CPU detect function for SIMD instruction sets.
int cpu_info_ = 0;
int InitCpuFlags() {
#ifdef CPU_X86
int cpu_info[4];
__cpuid(cpu_info, 1);
cpu_info_ = ((cpu_info[3] & 0x04000000) ? kCpuHasSSE2 : 0) |
((cpu_info[2] & 0x00000200) ? kCpuHasSSSE3 : 0) |
((cpu_info[2] & 0x00080000) ? kCpuHasSSE41 : 0) |
((cpu_info[2] & 0x00100000) ? kCpuHasSSE42 : 0) |
(((cpu_info[2] & 0x18000000) == 0x18000000) ? kCpuHasAVX : 0) |
kCpuInitialized | kCpuHasX86;
// environment variable overrides for testing.
if (getenv("LIBYUV_DISABLE_X86")) {
cpu_info_ &= ~kCpuHasX86;
}
if (getenv("LIBYUV_DISABLE_SSE2")) {
cpu_info_ &= ~kCpuHasSSE2;
}
if (getenv("LIBYUV_DISABLE_SSSE3")) {
cpu_info_ &= ~kCpuHasSSSE3;
}
if (getenv("LIBYUV_DISABLE_SSE41")) {
cpu_info_ &= ~kCpuHasSSE41;
}
if (getenv("LIBYUV_DISABLE_ASM")) {
cpu_info_ = kCpuInitialized;
}
#elif defined(__linux__) && defined(__ARM_NEON__)
cpu_info_ = ArmCpuCaps("/proc/cpuinfo") | kCpuInitialized;
#elif defined(__ARM_NEON__)
// gcc -mfpu=neon defines __ARM_NEON__
// Enable Neon if you want support for Neon and Arm, and use MaskCpuFlags
// to disable Neon on devices that do not have it.
cpu_info_ = kCpuHasNEON | kCpuInitialized | kCpuHasARM;
#else
cpu_info_ = kCpuInitialized | kCpuHasARM;
#endif
return cpu_info_;
}
void MaskCpuFlags(int enable_flags) {
InitCpuFlags();
cpu_info_ = (cpu_info_ & enable_flags) | kCpuInitialized;
}
#ifdef __cplusplus
} // extern "C"
} // namespace libyuv
#endif