ref: 0941ff72a00732cea6750477edfe649348e699de
dir: /third_party/libyuv/source/cpu_id.cc/
/* * Copyright 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" #if (defined(_MSC_VER) && !defined(__clang__)) && !defined(__clang__) #include <intrin.h> // For __cpuidex() #endif #if !defined(__pnacl__) && !defined(__CLR_VER) && \ !defined(__native_client__) && (defined(_M_IX86) || defined(_M_X64)) && \ defined(_MSC_VER) && !defined(__clang__) && (_MSC_FULL_VER >= 160040219) #include <immintrin.h> // For _xgetbv() #endif #if !defined(__native_client__) #include <stdlib.h> // For getenv() #endif // For ArmCpuCaps() but unittested on all platforms #include <stdio.h> #include <string.h> #include "libyuv/basic_types.h" // For CPU_X86 #ifdef __cplusplus namespace libyuv { extern "C" { #endif // For functions that use the stack and have runtime checks for overflow, // use SAFEBUFFERS to avoid additional check. #if (defined(_MSC_VER) && !defined(__clang__)) && (_MSC_FULL_VER >= 160040219) #define SAFEBUFFERS __declspec(safebuffers) #else #define SAFEBUFFERS #endif // Low level cpuid for X86. #if (defined(_M_IX86) || defined(_M_X64) || \ defined(__i386__) || defined(__x86_64__)) && \ !defined(__pnacl__) && !defined(__CLR_VER) LIBYUV_API void CpuId(uint32 info_eax, uint32 info_ecx, uint32* cpu_info) { #if (defined(_MSC_VER) && !defined(__clang__)) && !defined(__clang__) // Visual C version uses intrinsic or inline x86 assembly. #if (_MSC_FULL_VER >= 160040219) __cpuidex((int*)(cpu_info), info_eax, info_ecx); #elif defined(_M_IX86) __asm { mov eax, info_eax mov ecx, info_ecx mov edi, cpu_info cpuid mov [edi], eax mov [edi + 4], ebx mov [edi + 8], ecx mov [edi + 12], edx } #else if (info_ecx == 0) { __cpuid((int*)(cpu_info), info_eax); } else { cpu_info[3] = cpu_info[2] = cpu_info[1] = cpu_info[0] = 0; } #endif // GCC version uses inline x86 assembly. #else // (defined(_MSC_VER) && !defined(__clang__)) && !defined(__clang__) uint32 info_ebx, info_edx; asm volatile ( // NOLINT #if defined( __i386__) && defined(__PIC__) // Preserve ebx for fpic 32 bit. "mov %%ebx, %%edi \n" "cpuid \n" "xchg %%edi, %%ebx \n" : "=D" (info_ebx), #else "cpuid \n" : "=b" (info_ebx), #endif // defined( __i386__) && defined(__PIC__) "+a" (info_eax), "+c" (info_ecx), "=d" (info_edx)); cpu_info[0] = info_eax; cpu_info[1] = info_ebx; cpu_info[2] = info_ecx; cpu_info[3] = info_edx; #endif // (defined(_MSC_VER) && !defined(__clang__)) && !defined(__clang__) } #else // (defined(_M_IX86) || defined(_M_X64) ... LIBYUV_API void CpuId(uint32 eax, uint32 ecx, uint32* cpu_info) { cpu_info[0] = cpu_info[1] = cpu_info[2] = cpu_info[3] = 0; } #endif // TODO(fbarchard): Enable xgetbv when validator supports it. #if (defined(_M_IX86) || defined(_M_X64) || \ defined(__i386__) || defined(__x86_64__)) && \ !defined(__pnacl__) && !defined(__CLR_VER) && !defined(__native_client__) #define HAS_XGETBV // X86 CPUs have xgetbv to detect OS saves high parts of ymm registers. int TestOsSaveYmm() { uint32 xcr0 = 0u; #if (defined(_MSC_VER) && !defined(__clang__)) && (_MSC_FULL_VER >= 160040219) xcr0 = (uint32)(_xgetbv(0)); // VS2010 SP1 required. #elif defined(_M_IX86) && defined(_MSC_VER) && !defined(__clang__) __asm { xor ecx, ecx // xcr 0 _asm _emit 0x0f _asm _emit 0x01 _asm _emit 0xd0 // For VS2010 and earlier. mov xcr0, eax } #elif defined(__i386__) || defined(__x86_64__) asm(".byte 0x0f, 0x01, 0xd0" : "=a" (xcr0) : "c" (0) : "%edx"); #endif // defined(__i386__) || defined(__x86_64__) return((xcr0 & 6) == 6); // Is ymm saved? } #endif // defined(_M_IX86) || defined(_M_X64) .. // based on libvpx arm_cpudetect.c // For Arm, but public to allow testing on any CPU LIBYUV_API SAFEBUFFERS int ArmCpuCaps(const char* cpuinfo_name) { char cpuinfo_line[512]; FILE* f = fopen(cpuinfo_name, "r"); if (!f) { // Assume Neon if /proc/cpuinfo is unavailable. // This will occur for Chrome sandbox for Pepper or Render process. return kCpuHasNEON; } while (fgets(cpuinfo_line, sizeof(cpuinfo_line) - 1, f)) { if (memcmp(cpuinfo_line, "Features", 8) == 0) { char* p = strstr(cpuinfo_line, " neon"); if (p && (p[5] == ' ' || p[5] == '\n')) { fclose(f); return kCpuHasNEON; } // aarch64 uses asimd for Neon. p = strstr(cpuinfo_line, " asimd"); if (p && (p[6] == ' ' || p[6] == '\n')) { fclose(f); return kCpuHasNEON; } } } fclose(f); return 0; } #if defined(__mips__) && defined(__linux__) static int MipsCpuCaps(const char* search_string) { char cpuinfo_line[512]; const char* file_name = "/proc/cpuinfo"; FILE* f = fopen(file_name, "r"); if (!f) { // Assume DSP if /proc/cpuinfo is unavailable. // This will occur for Chrome sandbox for Pepper or Render process. return kCpuHasMIPS_DSP; } while (fgets(cpuinfo_line, sizeof(cpuinfo_line) - 1, f) != NULL) { if (strstr(cpuinfo_line, search_string) != NULL) { fclose(f); return kCpuHasMIPS_DSP; } } fclose(f); return 0; } #endif // CPU detect function for SIMD instruction sets. LIBYUV_API int cpu_info_ = kCpuInit; // cpu_info is not initialized yet. // Test environment variable for disabling CPU features. Any non-zero value // to disable. Zero ignored to make it easy to set the variable on/off. #if !defined(__native_client__) && !defined(_M_ARM) static LIBYUV_BOOL TestEnv(const char* name) { const char* var = getenv(name); if (var) { if (var[0] != '0') { return LIBYUV_TRUE; } } return LIBYUV_FALSE; } #else // nacl does not support getenv(). static LIBYUV_BOOL TestEnv(const char*) { return LIBYUV_FALSE; } #endif LIBYUV_API SAFEBUFFERS int InitCpuFlags(void) { #if !defined(__pnacl__) && !defined(__CLR_VER) && defined(CPU_X86) uint32 cpu_info0[4] = { 0, 0, 0, 0 }; uint32 cpu_info1[4] = { 0, 0, 0, 0 }; uint32 cpu_info7[4] = { 0, 0, 0, 0 }; CpuId(0, 0, cpu_info0); CpuId(1, 0, cpu_info1); if (cpu_info0[0] >= 7) { CpuId(7, 0, cpu_info7); } cpu_info_ = ((cpu_info1[3] & 0x04000000) ? kCpuHasSSE2 : 0) | ((cpu_info1[2] & 0x00000200) ? kCpuHasSSSE3 : 0) | ((cpu_info1[2] & 0x00080000) ? kCpuHasSSE41 : 0) | ((cpu_info1[2] & 0x00100000) ? kCpuHasSSE42 : 0) | ((cpu_info7[1] & 0x00000200) ? kCpuHasERMS : 0) | ((cpu_info1[2] & 0x00001000) ? kCpuHasFMA3 : 0) | kCpuHasX86; #ifdef HAS_XGETBV if ((cpu_info1[2] & 0x18000000) == 0x18000000 && // AVX and OSSave TestOsSaveYmm()) { // Saves YMM. cpu_info_ |= ((cpu_info7[1] & 0x00000020) ? kCpuHasAVX2 : 0) | kCpuHasAVX; } #endif // Environment variable overrides for testing. if (TestEnv("LIBYUV_DISABLE_X86")) { cpu_info_ &= ~kCpuHasX86; } if (TestEnv("LIBYUV_DISABLE_SSE2")) { cpu_info_ &= ~kCpuHasSSE2; } if (TestEnv("LIBYUV_DISABLE_SSSE3")) { cpu_info_ &= ~kCpuHasSSSE3; } if (TestEnv("LIBYUV_DISABLE_SSE41")) { cpu_info_ &= ~kCpuHasSSE41; } if (TestEnv("LIBYUV_DISABLE_SSE42")) { cpu_info_ &= ~kCpuHasSSE42; } if (TestEnv("LIBYUV_DISABLE_AVX")) { cpu_info_ &= ~kCpuHasAVX; } if (TestEnv("LIBYUV_DISABLE_AVX2")) { cpu_info_ &= ~kCpuHasAVX2; } if (TestEnv("LIBYUV_DISABLE_ERMS")) { cpu_info_ &= ~kCpuHasERMS; } if (TestEnv("LIBYUV_DISABLE_FMA3")) { cpu_info_ &= ~kCpuHasFMA3; } #endif #if defined(__mips__) && defined(__linux__) // Linux mips parse text file for dsp detect. cpu_info_ = MipsCpuCaps("dsp"); // set kCpuHasMIPS_DSP. #if defined(__mips_dspr2) cpu_info_ |= kCpuHasMIPS_DSPR2; #endif cpu_info_ |= kCpuHasMIPS; if (getenv("LIBYUV_DISABLE_MIPS")) { cpu_info_ &= ~kCpuHasMIPS; } if (getenv("LIBYUV_DISABLE_MIPS_DSP")) { cpu_info_ &= ~kCpuHasMIPS_DSP; } if (getenv("LIBYUV_DISABLE_MIPS_DSPR2")) { cpu_info_ &= ~kCpuHasMIPS_DSPR2; } #endif #if defined(__arm__) || defined(__aarch64__) // gcc -mfpu=neon defines __ARM_NEON__ // __ARM_NEON__ generates code that requires Neon. NaCL also requires Neon. // For Linux, /proc/cpuinfo can be tested but without that assume Neon. #if defined(__ARM_NEON__) || defined(__native_client__) || !defined(__linux__) cpu_info_ = kCpuHasNEON; // For aarch64(arm64), /proc/cpuinfo's feature is not complete, e.g. no neon // flag in it. // So for aarch64, neon enabling is hard coded here. #endif #if defined(__aarch64__) cpu_info_ = kCpuHasNEON; #else // Linux arm parse text file for neon detect. cpu_info_ = ArmCpuCaps("/proc/cpuinfo"); #endif cpu_info_ |= kCpuHasARM; if (TestEnv("LIBYUV_DISABLE_NEON")) { cpu_info_ &= ~kCpuHasNEON; } #endif // __arm__ if (TestEnv("LIBYUV_DISABLE_ASM")) { cpu_info_ = 0; } return cpu_info_; } LIBYUV_API void MaskCpuFlags(int enable_flags) { cpu_info_ = InitCpuFlags() & enable_flags; } #ifdef __cplusplus } // extern "C" } // namespace libyuv #endif