coffee/libyuv
1
0
Fork 0
mirror of https://chromium.googlesource.com/libyuv/libyuv synced 2025-12-08 01:36:47 +08:00
Code Issues Packages Projects Releases Wiki Activity

inline cpuid for better branch prediction

Browse Source 
BUG=none
TEST=disassembly shows 6 instructions (due to auto init)
Review URL: http://webrtc-codereview.appspot.com/285001

git-svn-id: http://libyuv.googlecode.com/svn/trunk@90 16f28f9a-4ce2-e073-06de-1de4eb20be90
This commit is contained in:
fbarchard@google.com 2011-11-22 00:40:39 +00:00
parent 12d048335d
commit 3c00cf04f3
3 changed files with 11 additions and 12 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
README.chromium
View File

@ -1,6 +1,6 @@
Name: libyuv
URL: http://code.google.com/p/libyuv/
Version: 89
Version: 90
License: BSD
License File: LICENSE

8
include/libyuv/cpu_id.h
View File

@ -24,7 +24,13 @@ static const int kCpuHasNEON = 4;
static const int kCpuInitialized = 8;
// Detect CPU has SSE2 etc.
bool TestCpuFlag(int flag);
// test_flag parameter should be one of kCpuHas constants above
// returns non-zero if instruction set is detected
static inline int TestCpuFlag(int test_flag) {
extern int cpu_info_;
extern int InitCpuFlags();
return (cpu_info_ ? cpu_info_ : InitCpuFlags()) & test_flag;
}
// For testing, allow CPU flags to be disabled.
// ie MaskCpuFlags(~kCpuHasSSSE3) to disable SSSE3.

13
source/cpu_id.cc
View File

@ -43,10 +43,9 @@ static inline void __cpuid(int cpu_info[4], int info_type) {
namespace libyuv {
// CPU detect function for SIMD instruction sets.
static int cpu_info_ = 0;
int cpu_info_ = 0;
// TODO(fbarchard): (cpu_info[2] & 0x10000000 ? kCpuHasAVX : 0)
static void InitCpuFlags() {
int InitCpuFlags() {
#ifdef CPU_X86
int cpu_info[4];
__cpuid(cpu_info, 1);
@ -65,6 +64,7 @@ static void InitCpuFlags() {
#else
cpu_info_ = kCpuInitialized;
#endif
return cpu_info_;
}
void MaskCpuFlags(int enable_flags) {
@ -72,11 +72,4 @@ void MaskCpuFlags(int enable_flags) {
cpu_info_ = (cpu_info_ & enable_flags) | kCpuInitialized;
}
bool TestCpuFlag(int flag) {
if (0 == cpu_info_) {
InitCpuFlags();
}
return (cpu_info_ & flag) ? true : false;
}
} // namespace libyuv