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| author | Julian Calaby <julian.calaby@gmail.com> | 2016-06-27 22:37:45 +1000 |
|---|---|---|
| committer | Erik de Castro Lopo <erikd@mega-nerd.com> | 2016-06-28 18:08:12 +1000 |
| commit | 79ca23ece346e80e3f188e6192b8393d693fe31b (patch) | |
| tree | 24cf695594354bcf956d5f2a4a5ffea0f6ce6e7b | |
| parent | e58a6e75495a4d74c0f504066390aaa42b418682 (diff) | |
| download | flac-79ca23ece346e80e3f188e6192b8393d693fe31b.tar.gz | |
libFLAC/cpu.c: Eliminate a branch in cpu_info_x86
Inverting all the if statements allows us to move the common code of
setting all the registers to zero outside the #if statement.
| -rw-r--r-- | src/libFLAC/cpu.c | 20 |
1 files changed, 9 insertions, 11 deletions
diff --git a/src/libFLAC/cpu.c b/src/libFLAC/cpu.c index a89d1627..592aee73 100644 --- a/src/libFLAC/cpu.c +++ b/src/libFLAC/cpu.c @@ -457,25 +457,23 @@ void FLAC__cpu_info_x86(FLAC__uint32 level, FLAC__uint32 *eax, FLAC__uint32 *ebx int cpuinfo[4]; int ext = level & 0x80000000; __cpuid(cpuinfo, ext); - if((unsigned)cpuinfo[0] < level) { - *eax = *ebx = *ecx = *edx = 0; - return; - } + if((unsigned)cpuinfo[0] >= level) { + cpu_id_ex (cpuinfo, ext); - cpu_id_ex (cpuinfo, ext); + *eax = cpuinfo[0]; *ebx = cpuinfo[1]; *ecx = cpuinfo[2]; *edx = cpuinfo[3]; - *eax = cpuinfo[0]; *ebx = cpuinfo[1]; *ecx = cpuinfo[2]; *edx = cpuinfo[3]; + return; + } #elif defined __GNUC__ && defined HAVE_CPUID_H FLAC__uint32 ext = level & 0x80000000; __cpuid(ext, *eax, *ebx, *ecx, *edx); - if (*eax < level) { - *eax = *ebx = *ecx = *edx = 0; + if (*eax >= level) { + __cpuid_count(level, 0, *eax, *ebx, *ecx, *edx); + return; } - __cpuid_count(level, 0, *eax, *ebx, *ecx, *edx); -#else - *eax = *ebx = *ecx = *edx = 0; #endif + *eax = *ebx = *ecx = *edx = 0; } #endif /* (FLAC__CPU_IA32 || FLAC__CPU_X86_64) && FLAC__HAS_X86INTRIN */ |