diff options
Diffstat (limited to 'thirdparty/libwebp/dsp/cpu.c')
| -rw-r--r-- | thirdparty/libwebp/dsp/cpu.c | 45 |
1 files changed, 40 insertions, 5 deletions
diff --git a/thirdparty/libwebp/dsp/cpu.c b/thirdparty/libwebp/dsp/cpu.c index cbb08db90a..b5583b6e9b 100644 --- a/thirdparty/libwebp/dsp/cpu.c +++ b/thirdparty/libwebp/dsp/cpu.c @@ -95,26 +95,62 @@ static WEBP_INLINE uint64_t xgetbv(void) { #endif #if defined(__i386__) || defined(__x86_64__) || defined(WEBP_MSC_SSE2) + +// helper function for run-time detection of slow SSSE3 platforms +static int CheckSlowModel(int info) { + // Table listing display models with longer latencies for the bsr instruction + // (ie 2 cycles vs 10/16 cycles) and some SSSE3 instructions like pshufb. + // Refer to Intel 64 and IA-32 Architectures Optimization Reference Manual. + static const uint8_t kSlowModels[] = { + 0x37, 0x4a, 0x4d, // Silvermont Microarchitecture + 0x1c, 0x26, 0x27 // Atom Microarchitecture + }; + const uint32_t model = ((info & 0xf0000) >> 12) | ((info >> 4) & 0xf); + const uint32_t family = (info >> 8) & 0xf; + if (family == 0x06) { + size_t i; + for (i = 0; i < sizeof(kSlowModels) / sizeof(kSlowModels[0]); ++i) { + if (model == kSlowModels[i]) return 1; + } + } + return 0; +} + static int x86CPUInfo(CPUFeature feature) { int max_cpuid_value; int cpu_info[4]; + int is_intel = 0; // get the highest feature value cpuid supports GetCPUInfo(cpu_info, 0); max_cpuid_value = cpu_info[0]; if (max_cpuid_value < 1) { return 0; + } else { + const int VENDOR_ID_INTEL_EBX = 0x756e6547; // uneG + const int VENDOR_ID_INTEL_EDX = 0x49656e69; // Ieni + const int VENDOR_ID_INTEL_ECX = 0x6c65746e; // letn + is_intel = (cpu_info[1] == VENDOR_ID_INTEL_EBX && + cpu_info[2] == VENDOR_ID_INTEL_ECX && + cpu_info[3] == VENDOR_ID_INTEL_EDX); // genuine Intel? } GetCPUInfo(cpu_info, 1); if (feature == kSSE2) { - return 0 != (cpu_info[3] & 0x04000000); + return !!(cpu_info[3] & (1 << 26)); } if (feature == kSSE3) { - return 0 != (cpu_info[2] & 0x00000001); + return !!(cpu_info[2] & (1 << 0)); + } + if (feature == kSlowSSSE3) { + if (is_intel && (cpu_info[2] & (1 << 0))) { // SSSE3? + return CheckSlowModel(cpu_info[0]); + } + return 0; } + if (feature == kSSE4_1) { - return 0 != (cpu_info[2] & 0x00080000); + return !!(cpu_info[2] & (1 << 19)); } if (feature == kAVX) { // bits 27 (OSXSAVE) & 28 (256-bit AVX) @@ -126,7 +162,7 @@ static int x86CPUInfo(CPUFeature feature) { if (feature == kAVX2) { if (x86CPUInfo(kAVX) && max_cpuid_value >= 7) { GetCPUInfo(cpu_info, 7); - return ((cpu_info[1] & 0x00000020) == 0x00000020); + return !!(cpu_info[1] & (1 << 5)); } } return 0; @@ -184,4 +220,3 @@ VP8CPUInfo VP8GetCPUInfo = mipsCPUInfo; #else VP8CPUInfo VP8GetCPUInfo = NULL; #endif - |