SDL_cpuinfo.h (9725B)
1 /* 2 Simple DirectMedia Layer 3 Copyright (C) 1997-2020 Sam Lantinga <slouken@libsdl.org> 4 5 This software is provided 'as-is', without any express or implied 6 warranty. In no event will the authors be held liable for any damages 7 arising from the use of this software. 8 9 Permission is granted to anyone to use this software for any purpose, 10 including commercial applications, and to alter it and redistribute it 11 freely, subject to the following restrictions: 12 13 1. The origin of this software must not be misrepresented; you must not 14 claim that you wrote the original software. If you use this software 15 in a product, an acknowledgment in the product documentation would be 16 appreciated but is not required. 17 2. Altered source versions must be plainly marked as such, and must not be 18 misrepresented as being the original software. 19 3. This notice may not be removed or altered from any source distribution. 20 */ 21 22 /** 23 * \file SDL_cpuinfo.h 24 * 25 * CPU feature detection for SDL. 26 */ 27 28 #ifndef SDL_cpuinfo_h_ 29 #define SDL_cpuinfo_h_ 30 31 #include "SDL_stdinc.h" 32 33 /* Need to do this here because intrin.h has C++ code in it */ 34 /* Visual Studio 2005 has a bug where intrin.h conflicts with winnt.h */ 35 #if defined(_MSC_VER) && (_MSC_VER >= 1500) && (defined(_M_IX86) || defined(_M_X64)) 36 #ifdef __clang__ 37 /* Many of the intrinsics SDL uses are not implemented by clang with Visual Studio */ 38 #undef __MMX__ 39 #undef __SSE__ 40 #undef __SSE2__ 41 #else 42 #include <intrin.h> 43 #ifndef _WIN64 44 #ifndef __MMX__ 45 #define __MMX__ 46 #endif 47 #ifndef __3dNOW__ 48 #define __3dNOW__ 49 #endif 50 #endif 51 #ifndef __SSE__ 52 #define __SSE__ 53 #endif 54 #ifndef __SSE2__ 55 #define __SSE2__ 56 #endif 57 #endif /* __clang__ */ 58 #elif defined(__MINGW64_VERSION_MAJOR) 59 #include <intrin.h> 60 #else 61 /* altivec.h redefining bool causes a number of problems, see bugs 3993 and 4392, so you need to explicitly define SDL_ENABLE_ALTIVEC_H to have it included. */ 62 #if defined(HAVE_ALTIVEC_H) && defined(__ALTIVEC__) && !defined(__APPLE_ALTIVEC__) && defined(SDL_ENABLE_ALTIVEC_H) 63 #include <altivec.h> 64 #endif 65 #if !defined(SDL_DISABLE_ARM_NEON_H) 66 # if defined(__ARM_NEON) 67 # include <arm_neon.h> 68 # elif defined(__WINDOWS__) || defined(__WINRT__) 69 /* Visual Studio doesn't define __ARM_ARCH, but _M_ARM (if set, always 7), and _M_ARM64 (if set, always 1). */ 70 # if defined(_M_ARM) 71 # include <armintr.h> 72 # include <arm_neon.h> 73 # define __ARM_NEON 1 /* Set __ARM_NEON so that it can be used elsewhere, at compile time */ 74 # endif 75 # if defined (_M_ARM64) 76 # include <arm64intr.h> 77 # include <arm64_neon.h> 78 # define __ARM_NEON 1 /* Set __ARM_NEON so that it can be used elsewhere, at compile time */ 79 # endif 80 # endif 81 #endif 82 #if defined(__3dNOW__) && !defined(SDL_DISABLE_MM3DNOW_H) 83 #include <mm3dnow.h> 84 #endif 85 #if defined(HAVE_IMMINTRIN_H) && !defined(SDL_DISABLE_IMMINTRIN_H) 86 #include <immintrin.h> 87 #else 88 #if defined(__MMX__) && !defined(SDL_DISABLE_MMINTRIN_H) 89 #include <mmintrin.h> 90 #endif 91 #if defined(__SSE__) && !defined(SDL_DISABLE_XMMINTRIN_H) 92 #include <xmmintrin.h> 93 #endif 94 #if defined(__SSE2__) && !defined(SDL_DISABLE_EMMINTRIN_H) 95 #include <emmintrin.h> 96 #endif 97 #if defined(__SSE3__) && !defined(SDL_DISABLE_PMMINTRIN_H) 98 #include <pmmintrin.h> 99 #endif 100 #endif /* HAVE_IMMINTRIN_H */ 101 #endif /* compiler version */ 102 103 #include "begin_code.h" 104 /* Set up for C function definitions, even when using C++ */ 105 #ifdef __cplusplus 106 extern "C" { 107 #endif 108 109 /* This is a guess for the cacheline size used for padding. 110 * Most x86 processors have a 64 byte cache line. 111 * The 64-bit PowerPC processors have a 128 byte cache line. 112 * We'll use the larger value to be generally safe. 113 */ 114 #define SDL_CACHELINE_SIZE 128 115 116 /** 117 * This function returns the number of CPU cores available. 118 */ 119 extern DECLSPEC int SDLCALL SDL_GetCPUCount(void); 120 121 /** 122 * This function returns the L1 cache line size of the CPU 123 * 124 * This is useful for determining multi-threaded structure padding 125 * or SIMD prefetch sizes. 126 */ 127 extern DECLSPEC int SDLCALL SDL_GetCPUCacheLineSize(void); 128 129 /** 130 * This function returns true if the CPU has the RDTSC instruction. 131 */ 132 extern DECLSPEC SDL_bool SDLCALL SDL_HasRDTSC(void); 133 134 /** 135 * This function returns true if the CPU has AltiVec features. 136 */ 137 extern DECLSPEC SDL_bool SDLCALL SDL_HasAltiVec(void); 138 139 /** 140 * This function returns true if the CPU has MMX features. 141 */ 142 extern DECLSPEC SDL_bool SDLCALL SDL_HasMMX(void); 143 144 /** 145 * This function returns true if the CPU has 3DNow! features. 146 */ 147 extern DECLSPEC SDL_bool SDLCALL SDL_Has3DNow(void); 148 149 /** 150 * This function returns true if the CPU has SSE features. 151 */ 152 extern DECLSPEC SDL_bool SDLCALL SDL_HasSSE(void); 153 154 /** 155 * This function returns true if the CPU has SSE2 features. 156 */ 157 extern DECLSPEC SDL_bool SDLCALL SDL_HasSSE2(void); 158 159 /** 160 * This function returns true if the CPU has SSE3 features. 161 */ 162 extern DECLSPEC SDL_bool SDLCALL SDL_HasSSE3(void); 163 164 /** 165 * This function returns true if the CPU has SSE4.1 features. 166 */ 167 extern DECLSPEC SDL_bool SDLCALL SDL_HasSSE41(void); 168 169 /** 170 * This function returns true if the CPU has SSE4.2 features. 171 */ 172 extern DECLSPEC SDL_bool SDLCALL SDL_HasSSE42(void); 173 174 /** 175 * This function returns true if the CPU has AVX features. 176 */ 177 extern DECLSPEC SDL_bool SDLCALL SDL_HasAVX(void); 178 179 /** 180 * This function returns true if the CPU has AVX2 features. 181 */ 182 extern DECLSPEC SDL_bool SDLCALL SDL_HasAVX2(void); 183 184 /** 185 * This function returns true if the CPU has AVX-512F (foundation) features. 186 */ 187 extern DECLSPEC SDL_bool SDLCALL SDL_HasAVX512F(void); 188 189 /** 190 * This function returns true if the CPU has ARM SIMD (ARMv6) features. 191 */ 192 extern DECLSPEC SDL_bool SDLCALL SDL_HasARMSIMD(void); 193 194 /** 195 * This function returns true if the CPU has NEON (ARM SIMD) features. 196 */ 197 extern DECLSPEC SDL_bool SDLCALL SDL_HasNEON(void); 198 199 /** 200 * This function returns the amount of RAM configured in the system, in MB. 201 */ 202 extern DECLSPEC int SDLCALL SDL_GetSystemRAM(void); 203 204 /** 205 * \brief Report the alignment this system needs for SIMD allocations. 206 * 207 * This will return the minimum number of bytes to which a pointer must be 208 * aligned to be compatible with SIMD instructions on the current machine. 209 * For example, if the machine supports SSE only, it will return 16, but if 210 * it supports AVX-512F, it'll return 64 (etc). This only reports values for 211 * instruction sets SDL knows about, so if your SDL build doesn't have 212 * SDL_HasAVX512F(), then it might return 16 for the SSE support it sees and 213 * not 64 for the AVX-512 instructions that exist but SDL doesn't know about. 214 * Plan accordingly. 215 */ 216 extern DECLSPEC size_t SDLCALL SDL_SIMDGetAlignment(void); 217 218 /** 219 * \brief Allocate memory in a SIMD-friendly way. 220 * 221 * This will allocate a block of memory that is suitable for use with SIMD 222 * instructions. Specifically, it will be properly aligned and padded for 223 * the system's supported vector instructions. 224 * 225 * The memory returned will be padded such that it is safe to read or write 226 * an incomplete vector at the end of the memory block. This can be useful 227 * so you don't have to drop back to a scalar fallback at the end of your 228 * SIMD processing loop to deal with the final elements without overflowing 229 * the allocated buffer. 230 * 231 * You must free this memory with SDL_FreeSIMD(), not free() or SDL_free() 232 * or delete[], etc. 233 * 234 * Note that SDL will only deal with SIMD instruction sets it is aware of; 235 * for example, SDL 2.0.8 knows that SSE wants 16-byte vectors 236 * (SDL_HasSSE()), and AVX2 wants 32 bytes (SDL_HasAVX2()), but doesn't 237 * know that AVX-512 wants 64. To be clear: if you can't decide to use an 238 * instruction set with an SDL_Has*() function, don't use that instruction 239 * set with memory allocated through here. 240 * 241 * SDL_AllocSIMD(0) will return a non-NULL pointer, assuming the system isn't 242 * out of memory. 243 * 244 * \param len The length, in bytes, of the block to allocated. The actual 245 * allocated block might be larger due to padding, etc. 246 * \return Pointer to newly-allocated block, NULL if out of memory. 247 * 248 * \sa SDL_SIMDAlignment 249 * \sa SDL_SIMDRealloc 250 * \sa SDL_SIMDFree 251 */ 252 extern DECLSPEC void * SDLCALL SDL_SIMDAlloc(const size_t len); 253 254 /** 255 * \brief Reallocate memory obtained from SDL_SIMDAlloc 256 * 257 * It is not valid to use this function on a pointer from anything but 258 * SDL_SIMDAlloc(). It can't be used on pointers from malloc, realloc, 259 * SDL_malloc, memalign, new[], etc. 260 * 261 * \param mem The pointer obtained from SDL_SIMDAlloc. This function also 262 * accepts NULL, at which point this function is the same as 263 * calling SDL_realloc with a NULL pointer. 264 * \param len The length, in bytes, of the block to allocated. The actual 265 * allocated block might be larger due to padding, etc. Passing 0 266 * will return a non-NULL pointer, assuming the system isn't out of 267 * memory. 268 * \return Pointer to newly-reallocated block, NULL if out of memory. 269 * 270 * \sa SDL_SIMDAlignment 271 * \sa SDL_SIMDAlloc 272 * \sa SDL_SIMDFree 273 */ 274 extern DECLSPEC void * SDLCALL SDL_SIMDRealloc(void *mem, const size_t len); 275 276 /** 277 * \brief Deallocate memory obtained from SDL_SIMDAlloc 278 * 279 * It is not valid to use this function on a pointer from anything but 280 * SDL_SIMDAlloc(). It can't be used on pointers from malloc, realloc, 281 * SDL_malloc, memalign, new[], etc. 282 * 283 * However, SDL_SIMDFree(NULL) is a legal no-op. 284 * 285 * \sa SDL_SIMDAlloc 286 * \sa SDL_SIMDRealloc 287 */ 288 extern DECLSPEC void SDLCALL SDL_SIMDFree(void *ptr); 289 290 /* vi: set ts=4 sw=4 expandtab: */ 291 /* Ends C function definitions when using C++ */ 292 #ifdef __cplusplus 293 } 294 #endif 295 #include "close_code.h" 296 297 #endif /* SDL_cpuinfo_h_ */ 298 299 /* vi: set ts=4 sw=4 expandtab: */