libyuv/source/cpu_id.cc
fbarchard@google.com 891091c6d4 cpu_id using one variable and make it more public how to set flags to disable SIMD
BUG=none
TEST=scale unittest in talk disables SSSE3
Review URL: http://webrtc-codereview.appspot.com/239018

git-svn-id: http://libyuv.googlecode.com/svn/trunk@47 16f28f9a-4ce2-e073-06de-1de4eb20be90
2011-10-29 00:18:58 +00:00

78 lines
2.2 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"
#include "libyuv/basic_types.h" // for CPU_X86
#ifdef _MSC_VER
#include <intrin.h>
#endif
// Internal flag to indicate cpuid is initialized.
static const int kCpuInitialized = 16;
// 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
namespace libyuv {
// CPU detect function for SIMD instruction sets.
static int cpu_info_ = 0;
// TODO(fbarchard): (cpu_info[2] & 0x10000000 ? kCpuHasAVX : 0)
static void 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) |
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;
#else
cpu_info_ = kCpuInitialized;
#endif
}
void MaskCpuFlags(int enable_flags) {
InitCpuFlags();
cpu_info_ = (cpu_info_ & enable_flags) | kCpuInitialized;
}
bool TestCpuFlag(int flag) {
if (!cpu_info_) {
InitCpuFlags();
}
return cpu_info_ & flag ? true : false;
}
} // namespace libyuv