1 /* 2 * Copyright 2011 The LibYuv Project Authors. All rights reserved. 3 * 4 * Use of this source code is governed by a BSD-style license 5 * that can be found in the LICENSE file in the root of the source 6 * tree. An additional intellectual property rights grant can be found 7 * in the file PATENTS. All contributing project authors may 8 * be found in the AUTHORS file in the root of the source tree. 9 */ 10 11 #include "libyuv/cpu_id.h" 12 13 #if defined(_MSC_VER) 14 #include <intrin.h> // For __cpuidex() 15 #endif 16 #if !defined(__pnacl__) && !defined(__CLR_VER) && \ 17 !defined(__native_client__) && (defined(_M_IX86) || defined(_M_X64)) && \ 18 defined(_MSC_FULL_VER) && (_MSC_FULL_VER >= 160040219) 19 #include <immintrin.h> // For _xgetbv() 20 #endif 21 22 #if !defined(__native_client__) 23 #include <stdlib.h> // For getenv() 24 #endif 25 26 // For ArmCpuCaps() but unittested on all platforms 27 #include <stdio.h> 28 #include <string.h> 29 30 #include "libyuv/basic_types.h" // For CPU_X86 31 32 #ifdef __cplusplus 33 namespace libyuv { 34 extern "C" { 35 #endif 36 37 // For functions that use the stack and have runtime checks for overflow, 38 // use SAFEBUFFERS to avoid additional check. 39 #if defined(_MSC_FULL_VER) && (_MSC_FULL_VER >= 160040219) && \ 40 !defined(__clang__) 41 #define SAFEBUFFERS __declspec(safebuffers) 42 #else 43 #define SAFEBUFFERS 44 #endif 45 46 // Low level cpuid for X86. 47 #if (defined(_M_IX86) || defined(_M_X64) || defined(__i386__) || \ 48 defined(__x86_64__)) && \ 49 !defined(__pnacl__) && !defined(__CLR_VER) 50 LIBYUV_API 51 void CpuId(uint32 info_eax, uint32 info_ecx, uint32* cpu_info) { 52 #if defined(_MSC_VER) 53 // Visual C version uses intrinsic or inline x86 assembly. 54 #if defined(_MSC_FULL_VER) && (_MSC_FULL_VER >= 160040219) 55 __cpuidex((int*)(cpu_info), info_eax, info_ecx); 56 #elif defined(_M_IX86) 57 __asm { 58 mov eax, info_eax 59 mov ecx, info_ecx 60 mov edi, cpu_info 61 cpuid 62 mov [edi], eax 63 mov [edi + 4], ebx 64 mov [edi + 8], ecx 65 mov [edi + 12], edx 66 } 67 #else // Visual C but not x86 68 if (info_ecx == 0) { 69 __cpuid((int*)(cpu_info), info_eax); 70 } else { 71 cpu_info[3] = cpu_info[2] = cpu_info[1] = cpu_info[0] = 0u; 72 } 73 #endif 74 // GCC version uses inline x86 assembly. 75 #else // defined(_MSC_VER) 76 uint32 info_ebx, info_edx; 77 asm volatile( 78 #if defined(__i386__) && defined(__PIC__) 79 // Preserve ebx for fpic 32 bit. 80 "mov %%ebx, %%edi \n" 81 "cpuid \n" 82 "xchg %%edi, %%ebx \n" 83 : "=D"(info_ebx), 84 #else 85 "cpuid \n" 86 : "=b"(info_ebx), 87 #endif // defined( __i386__) && defined(__PIC__) 88 "+a"(info_eax), "+c"(info_ecx), "=d"(info_edx)); 89 cpu_info[0] = info_eax; 90 cpu_info[1] = info_ebx; 91 cpu_info[2] = info_ecx; 92 cpu_info[3] = info_edx; 93 #endif // defined(_MSC_VER) 94 } 95 #else // (defined(_M_IX86) || defined(_M_X64) ... 96 LIBYUV_API 97 void CpuId(uint32 eax, uint32 ecx, uint32* cpu_info) { 98 (void)eax; 99 (void)ecx; 100 cpu_info[0] = cpu_info[1] = cpu_info[2] = cpu_info[3] = 0; 101 } 102 #endif 103 104 // For VS2010 and earlier emit can be used: 105 // _asm _emit 0x0f _asm _emit 0x01 _asm _emit 0xd0 // For VS2010 and earlier. 106 // __asm { 107 // xor ecx, ecx // xcr 0 108 // xgetbv 109 // mov xcr0, eax 110 // } 111 // For VS2013 and earlier 32 bit, the _xgetbv(0) optimizer produces bad code. 112 // https://code.google.com/p/libyuv/issues/detail?id=529 113 #if defined(_M_IX86) && (_MSC_VER < 1900) 114 #pragma optimize("g", off) 115 #endif 116 #if (defined(_M_IX86) || defined(_M_X64) || defined(__i386__) || \ 117 defined(__x86_64__)) && \ 118 !defined(__pnacl__) && !defined(__CLR_VER) && !defined(__native_client__) 119 // X86 CPUs have xgetbv to detect OS saves high parts of ymm registers. 120 int GetXCR0() { 121 uint32 xcr0 = 0u; 122 #if defined(_MSC_FULL_VER) && (_MSC_FULL_VER >= 160040219) 123 xcr0 = (uint32)(_xgetbv(0)); // VS2010 SP1 required. 124 #elif defined(__i386__) || defined(__x86_64__) 125 asm(".byte 0x0f, 0x01, 0xd0" : "=a"(xcr0) : "c"(0) : "%edx"); 126 #endif // defined(__i386__) || defined(__x86_64__) 127 return xcr0; 128 } 129 #else 130 // xgetbv unavailable to query for OSSave support. Return 0. 131 #define GetXCR0() 0 132 #endif // defined(_M_IX86) || defined(_M_X64) .. 133 // Return optimization to previous setting. 134 #if defined(_M_IX86) && (_MSC_VER < 1900) 135 #pragma optimize("g", on) 136 #endif 137 138 // based on libvpx arm_cpudetect.c 139 // For Arm, but public to allow testing on any CPU 140 LIBYUV_API SAFEBUFFERS int ArmCpuCaps(const char* cpuinfo_name) { 141 char cpuinfo_line[512]; 142 FILE* f = fopen(cpuinfo_name, "r"); 143 if (!f) { 144 // Assume Neon if /proc/cpuinfo is unavailable. 145 // This will occur for Chrome sandbox for Pepper or Render process. 146 return kCpuHasNEON; 147 } 148 while (fgets(cpuinfo_line, sizeof(cpuinfo_line) - 1, f)) { 149 if (memcmp(cpuinfo_line, "Features", 8) == 0) { 150 char* p = strstr(cpuinfo_line, " neon"); 151 if (p && (p[5] == ' ' || p[5] == '\n')) { 152 fclose(f); 153 return kCpuHasNEON; 154 } 155 // aarch64 uses asimd for Neon. 156 p = strstr(cpuinfo_line, " asimd"); 157 if (p && (p[6] == ' ' || p[6] == '\n')) { 158 fclose(f); 159 return kCpuHasNEON; 160 } 161 } 162 } 163 fclose(f); 164 return 0; 165 } 166 167 LIBYUV_API SAFEBUFFERS int MipsCpuCaps(const char* cpuinfo_name, 168 const char ase[]) { 169 char cpuinfo_line[512]; 170 int len = (int)strlen(ase); 171 FILE* f = fopen(cpuinfo_name, "r"); 172 if (!f) { 173 // ase enabled if /proc/cpuinfo is unavailable. 174 if (strcmp(ase, " msa") == 0) { 175 return kCpuHasMSA; 176 } 177 return kCpuHasDSPR2; 178 } 179 while (fgets(cpuinfo_line, sizeof(cpuinfo_line) - 1, f)) { 180 if (memcmp(cpuinfo_line, "ASEs implemented", 16) == 0) { 181 char* p = strstr(cpuinfo_line, ase); 182 if (p && (p[len] == ' ' || p[len] == '\n')) { 183 fclose(f); 184 if (strcmp(ase, " msa") == 0) { 185 return kCpuHasMSA; 186 } 187 return kCpuHasDSPR2; 188 } 189 } 190 } 191 fclose(f); 192 return 0; 193 } 194 195 // CPU detect function for SIMD instruction sets. 196 LIBYUV_API 197 int cpu_info_ = 0; // cpu_info is not initialized yet. 198 199 // Test environment variable for disabling CPU features. Any non-zero value 200 // to disable. Zero ignored to make it easy to set the variable on/off. 201 #if !defined(__native_client__) && !defined(_M_ARM) 202 203 static LIBYUV_BOOL TestEnv(const char* name) { 204 const char* var = getenv(name); 205 if (var) { 206 if (var[0] != '0') { 207 return LIBYUV_TRUE; 208 } 209 } 210 return LIBYUV_FALSE; 211 } 212 #else // nacl does not support getenv(). 213 static LIBYUV_BOOL TestEnv(const char*) { 214 return LIBYUV_FALSE; 215 } 216 #endif 217 218 LIBYUV_API SAFEBUFFERS int InitCpuFlags(void) { 219 int cpu_info = 0; 220 #if !defined(__pnacl__) && !defined(__CLR_VER) && defined(CPU_X86) 221 uint32 cpu_info0[4] = {0, 0, 0, 0}; 222 uint32 cpu_info1[4] = {0, 0, 0, 0}; 223 uint32 cpu_info7[4] = {0, 0, 0, 0}; 224 CpuId(0, 0, cpu_info0); 225 CpuId(1, 0, cpu_info1); 226 if (cpu_info0[0] >= 7) { 227 CpuId(7, 0, cpu_info7); 228 } 229 cpu_info = kCpuHasX86 | ((cpu_info1[3] & 0x04000000) ? kCpuHasSSE2 : 0) | 230 ((cpu_info1[2] & 0x00000200) ? kCpuHasSSSE3 : 0) | 231 ((cpu_info1[2] & 0x00080000) ? kCpuHasSSE41 : 0) | 232 ((cpu_info1[2] & 0x00100000) ? kCpuHasSSE42 : 0) | 233 ((cpu_info7[1] & 0x00000200) ? kCpuHasERMS : 0); 234 235 // AVX requires OS saves YMM registers. 236 if (((cpu_info1[2] & 0x1c000000) == 0x1c000000) && // AVX and OSXSave 237 ((GetXCR0() & 6) == 6)) { // Test OS saves YMM registers 238 cpu_info |= kCpuHasAVX | ((cpu_info7[1] & 0x00000020) ? kCpuHasAVX2 : 0) | 239 ((cpu_info1[2] & 0x00001000) ? kCpuHasFMA3 : 0) | 240 ((cpu_info1[2] & 0x20000000) ? kCpuHasF16C : 0); 241 242 // Detect AVX512bw 243 if ((GetXCR0() & 0xe0) == 0xe0) { 244 cpu_info |= (cpu_info7[1] & 0x40000000) ? kCpuHasAVX3 : 0; 245 } 246 } 247 248 // Environment variable overrides for testing. 249 if (TestEnv("LIBYUV_DISABLE_X86")) { 250 cpu_info &= ~kCpuHasX86; 251 } 252 if (TestEnv("LIBYUV_DISABLE_SSE2")) { 253 cpu_info &= ~kCpuHasSSE2; 254 } 255 if (TestEnv("LIBYUV_DISABLE_SSSE3")) { 256 cpu_info &= ~kCpuHasSSSE3; 257 } 258 if (TestEnv("LIBYUV_DISABLE_SSE41")) { 259 cpu_info &= ~kCpuHasSSE41; 260 } 261 if (TestEnv("LIBYUV_DISABLE_SSE42")) { 262 cpu_info &= ~kCpuHasSSE42; 263 } 264 if (TestEnv("LIBYUV_DISABLE_AVX")) { 265 cpu_info &= ~kCpuHasAVX; 266 } 267 if (TestEnv("LIBYUV_DISABLE_AVX2")) { 268 cpu_info &= ~kCpuHasAVX2; 269 } 270 if (TestEnv("LIBYUV_DISABLE_ERMS")) { 271 cpu_info &= ~kCpuHasERMS; 272 } 273 if (TestEnv("LIBYUV_DISABLE_FMA3")) { 274 cpu_info &= ~kCpuHasFMA3; 275 } 276 if (TestEnv("LIBYUV_DISABLE_AVX3")) { 277 cpu_info &= ~kCpuHasAVX3; 278 } 279 if (TestEnv("LIBYUV_DISABLE_F16C")) { 280 cpu_info &= ~kCpuHasF16C; 281 } 282 283 #endif 284 #if defined(__mips__) && defined(__linux__) 285 #if defined(__mips_dspr2) 286 cpu_info |= kCpuHasDSPR2; 287 #endif 288 #if defined(__mips_msa) 289 cpu_info = MipsCpuCaps("/proc/cpuinfo", " msa"); 290 #endif 291 cpu_info |= kCpuHasMIPS; 292 if (getenv("LIBYUV_DISABLE_DSPR2")) { 293 cpu_info &= ~kCpuHasDSPR2; 294 } 295 if (getenv("LIBYUV_DISABLE_MSA")) { 296 cpu_info &= ~kCpuHasMSA; 297 } 298 #endif 299 #if defined(__arm__) || defined(__aarch64__) 300 // gcc -mfpu=neon defines __ARM_NEON__ 301 // __ARM_NEON__ generates code that requires Neon. NaCL also requires Neon. 302 // For Linux, /proc/cpuinfo can be tested but without that assume Neon. 303 #if defined(__ARM_NEON__) || defined(__native_client__) || !defined(__linux__) 304 cpu_info = kCpuHasNEON; 305 // For aarch64(arm64), /proc/cpuinfo's feature is not complete, e.g. no neon 306 // flag in it. 307 // So for aarch64, neon enabling is hard coded here. 308 #endif 309 #if defined(__aarch64__) 310 cpu_info = kCpuHasNEON; 311 #else 312 // Linux arm parse text file for neon detect. 313 cpu_info = ArmCpuCaps("/proc/cpuinfo"); 314 #endif 315 cpu_info |= kCpuHasARM; 316 if (TestEnv("LIBYUV_DISABLE_NEON")) { 317 cpu_info &= ~kCpuHasNEON; 318 } 319 #endif // __arm__ 320 if (TestEnv("LIBYUV_DISABLE_ASM")) { 321 cpu_info = 0; 322 } 323 cpu_info |= kCpuInitialized; 324 cpu_info_ = cpu_info; 325 return cpu_info; 326 } 327 328 // Note that use of this function is not thread safe. 329 LIBYUV_API 330 void MaskCpuFlags(int enable_flags) { 331 cpu_info_ = InitCpuFlags() & enable_flags; 332 } 333 334 #ifdef __cplusplus 335 } // extern "C" 336 } // namespace libyuv 337 #endif 338
