| 1 | /* |
| 2 | * Copyright (c) Meta Platforms, Inc. and affiliates. |
| 3 | * All rights reserved. |
| 4 | * |
| 5 | * This source code is licensed under both the BSD-style license (found in the |
| 6 | * LICENSE file in the root directory of this source tree) and the GPLv2 (found |
| 7 | * in the COPYING file in the root directory of this source tree). |
| 8 | * You may select, at your option, one of the above-listed licenses. |
| 9 | */ |
| 10 | |
| 11 | #ifndef MEM_H_MODULE |
| 12 | #define MEM_H_MODULE |
| 13 | |
| 14 | #if defined (__cplusplus) |
| 15 | extern "C" { |
| 16 | #endif |
| 17 | |
| 18 | /*-**************************************** |
| 19 | * Dependencies |
| 20 | ******************************************/ |
| 21 | #include <stddef.h> /* size_t, ptrdiff_t */ |
| 22 | #include "compiler.h" /* __has_builtin */ |
| 23 | #include "debug.h" /* DEBUG_STATIC_ASSERT */ |
| 24 | #include "zstd_deps.h" /* ZSTD_memcpy */ |
| 25 | |
| 26 | |
| 27 | /*-**************************************** |
| 28 | * Compiler specifics |
| 29 | ******************************************/ |
| 30 | #if defined(_MSC_VER) /* Visual Studio */ |
| 31 | # include <stdlib.h> /* _byteswap_ulong */ |
| 32 | # include <intrin.h> /* _byteswap_* */ |
| 33 | #endif |
| 34 | #if defined(__GNUC__) |
| 35 | # define MEM_STATIC static __inline __attribute__((unused)) |
| 36 | #elif defined (__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */) |
| 37 | # define MEM_STATIC static inline |
| 38 | #elif defined(_MSC_VER) |
| 39 | # define MEM_STATIC static __inline |
| 40 | #else |
| 41 | # define MEM_STATIC static /* this version may generate warnings for unused static functions; disable the relevant warning */ |
| 42 | #endif |
| 43 | |
| 44 | /*-************************************************************** |
| 45 | * Basic Types |
| 46 | *****************************************************************/ |
| 47 | #if !defined (__VMS) && (defined (__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */) ) |
| 48 | # if defined(_AIX) |
| 49 | # include <inttypes.h> |
| 50 | # else |
| 51 | # include <stdint.h> /* intptr_t */ |
| 52 | # endif |
| 53 | typedef uint8_t BYTE; |
| 54 | typedef uint8_t U8; |
| 55 | typedef int8_t S8; |
| 56 | typedef uint16_t U16; |
| 57 | typedef int16_t S16; |
| 58 | typedef uint32_t U32; |
| 59 | typedef int32_t S32; |
| 60 | typedef uint64_t U64; |
| 61 | typedef int64_t S64; |
| 62 | #else |
| 63 | # include <limits.h> |
| 64 | #if CHAR_BIT != 8 |
| 65 | # error "this implementation requires char to be exactly 8-bit type" |
| 66 | #endif |
| 67 | typedef unsigned char BYTE; |
| 68 | typedef unsigned char U8; |
| 69 | typedef signed char S8; |
| 70 | #if USHRT_MAX != 65535 |
| 71 | # error "this implementation requires short to be exactly 16-bit type" |
| 72 | #endif |
| 73 | typedef unsigned short U16; |
| 74 | typedef signed short S16; |
| 75 | #if UINT_MAX != 4294967295 |
| 76 | # error "this implementation requires int to be exactly 32-bit type" |
| 77 | #endif |
| 78 | typedef unsigned int U32; |
| 79 | typedef signed int S32; |
| 80 | /* note : there are no limits defined for long long type in C90. |
| 81 | * limits exist in C99, however, in such case, <stdint.h> is preferred */ |
| 82 | typedef unsigned long long U64; |
| 83 | typedef signed long long S64; |
| 84 | #endif |
| 85 | |
| 86 | |
| 87 | /*-************************************************************** |
| 88 | * Memory I/O API |
| 89 | *****************************************************************/ |
| 90 | /*=== Static platform detection ===*/ |
| 91 | MEM_STATIC unsigned MEM_32bits(void); |
| 92 | MEM_STATIC unsigned MEM_64bits(void); |
| 93 | MEM_STATIC unsigned MEM_isLittleEndian(void); |
| 94 | |
| 95 | /*=== Native unaligned read/write ===*/ |
| 96 | MEM_STATIC U16 MEM_read16(const void* memPtr); |
| 97 | MEM_STATIC U32 MEM_read32(const void* memPtr); |
| 98 | MEM_STATIC U64 MEM_read64(const void* memPtr); |
| 99 | MEM_STATIC size_t MEM_readST(const void* memPtr); |
| 100 | |
| 101 | MEM_STATIC void MEM_write16(void* memPtr, U16 value); |
| 102 | MEM_STATIC void MEM_write32(void* memPtr, U32 value); |
| 103 | MEM_STATIC void MEM_write64(void* memPtr, U64 value); |
| 104 | |
| 105 | /*=== Little endian unaligned read/write ===*/ |
| 106 | MEM_STATIC U16 MEM_readLE16(const void* memPtr); |
| 107 | MEM_STATIC U32 MEM_readLE24(const void* memPtr); |
| 108 | MEM_STATIC U32 MEM_readLE32(const void* memPtr); |
| 109 | MEM_STATIC U64 MEM_readLE64(const void* memPtr); |
| 110 | MEM_STATIC size_t MEM_readLEST(const void* memPtr); |
| 111 | |
| 112 | MEM_STATIC void MEM_writeLE16(void* memPtr, U16 val); |
| 113 | MEM_STATIC void MEM_writeLE24(void* memPtr, U32 val); |
| 114 | MEM_STATIC void MEM_writeLE32(void* memPtr, U32 val32); |
| 115 | MEM_STATIC void MEM_writeLE64(void* memPtr, U64 val64); |
| 116 | MEM_STATIC void MEM_writeLEST(void* memPtr, size_t val); |
| 117 | |
| 118 | /*=== Big endian unaligned read/write ===*/ |
| 119 | MEM_STATIC U32 MEM_readBE32(const void* memPtr); |
| 120 | MEM_STATIC U64 MEM_readBE64(const void* memPtr); |
| 121 | MEM_STATIC size_t MEM_readBEST(const void* memPtr); |
| 122 | |
| 123 | MEM_STATIC void MEM_writeBE32(void* memPtr, U32 val32); |
| 124 | MEM_STATIC void MEM_writeBE64(void* memPtr, U64 val64); |
| 125 | MEM_STATIC void MEM_writeBEST(void* memPtr, size_t val); |
| 126 | |
| 127 | /*=== Byteswap ===*/ |
| 128 | MEM_STATIC U32 MEM_swap32(U32 in); |
| 129 | MEM_STATIC U64 MEM_swap64(U64 in); |
| 130 | MEM_STATIC size_t MEM_swapST(size_t in); |
| 131 | |
| 132 | |
| 133 | /*-************************************************************** |
| 134 | * Memory I/O Implementation |
| 135 | *****************************************************************/ |
| 136 | /* MEM_FORCE_MEMORY_ACCESS : For accessing unaligned memory: |
| 137 | * Method 0 : always use `memcpy()`. Safe and portable. |
| 138 | * Method 1 : Use compiler extension to set unaligned access. |
| 139 | * Method 2 : direct access. This method is portable but violate C standard. |
| 140 | * It can generate buggy code on targets depending on alignment. |
| 141 | * Default : method 1 if supported, else method 0 |
| 142 | */ |
| 143 | #ifndef MEM_FORCE_MEMORY_ACCESS /* can be defined externally, on command line for example */ |
| 144 | # ifdef __GNUC__ |
| 145 | # define MEM_FORCE_MEMORY_ACCESS 1 |
| 146 | # endif |
| 147 | #endif |
| 148 | |
| 149 | MEM_STATIC unsigned MEM_32bits(void) { return sizeof(size_t)==4; } |
| 150 | MEM_STATIC unsigned MEM_64bits(void) { return sizeof(size_t)==8; } |
| 151 | |
| 152 | MEM_STATIC unsigned MEM_isLittleEndian(void) |
| 153 | { |
| 154 | #if defined(__BYTE_ORDER__) && defined(__ORDER_LITTLE_ENDIAN__) && (__BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__) |
| 155 | return 1; |
| 156 | #elif defined(__BYTE_ORDER__) && defined(__ORDER_BIG_ENDIAN__) && (__BYTE_ORDER__ == __ORDER_BIG_ENDIAN__) |
| 157 | return 0; |
| 158 | #elif defined(__clang__) && __LITTLE_ENDIAN__ |
| 159 | return 1; |
| 160 | #elif defined(__clang__) && __BIG_ENDIAN__ |
| 161 | return 0; |
| 162 | #elif defined(_MSC_VER) && (_M_AMD64 || _M_IX86) |
| 163 | return 1; |
| 164 | #elif defined(__DMC__) && defined(_M_IX86) |
| 165 | return 1; |
| 166 | #else |
| 167 | const union { U32 u; BYTE c[4]; } one = { 1 }; /* don't use static : performance detrimental */ |
| 168 | return one.c[0]; |
| 169 | #endif |
| 170 | } |
| 171 | |
| 172 | #if defined(MEM_FORCE_MEMORY_ACCESS) && (MEM_FORCE_MEMORY_ACCESS==2) |
| 173 | |
| 174 | /* violates C standard, by lying on structure alignment. |
| 175 | Only use if no other choice to achieve best performance on target platform */ |
| 176 | MEM_STATIC U16 MEM_read16(const void* memPtr) { return *(const U16*) memPtr; } |
| 177 | MEM_STATIC U32 MEM_read32(const void* memPtr) { return *(const U32*) memPtr; } |
| 178 | MEM_STATIC U64 MEM_read64(const void* memPtr) { return *(const U64*) memPtr; } |
| 179 | MEM_STATIC size_t MEM_readST(const void* memPtr) { return *(const size_t*) memPtr; } |
| 180 | |
| 181 | MEM_STATIC void MEM_write16(void* memPtr, U16 value) { *(U16*)memPtr = value; } |
| 182 | MEM_STATIC void MEM_write32(void* memPtr, U32 value) { *(U32*)memPtr = value; } |
| 183 | MEM_STATIC void MEM_write64(void* memPtr, U64 value) { *(U64*)memPtr = value; } |
| 184 | |
| 185 | #elif defined(MEM_FORCE_MEMORY_ACCESS) && (MEM_FORCE_MEMORY_ACCESS==1) |
| 186 | |
| 187 | typedef __attribute__((aligned(1))) U16 unalign16; |
| 188 | typedef __attribute__((aligned(1))) U32 unalign32; |
| 189 | typedef __attribute__((aligned(1))) U64 unalign64; |
| 190 | typedef __attribute__((aligned(1))) size_t unalignArch; |
| 191 | |
| 192 | MEM_STATIC U16 MEM_read16(const void* ptr) { return *(const unalign16*)ptr; } |
| 193 | MEM_STATIC U32 MEM_read32(const void* ptr) { return *(const unalign32*)ptr; } |
| 194 | MEM_STATIC U64 MEM_read64(const void* ptr) { return *(const unalign64*)ptr; } |
| 195 | MEM_STATIC size_t MEM_readST(const void* ptr) { return *(const unalignArch*)ptr; } |
| 196 | |
| 197 | MEM_STATIC void MEM_write16(void* memPtr, U16 value) { *(unalign16*)memPtr = value; } |
| 198 | MEM_STATIC void MEM_write32(void* memPtr, U32 value) { *(unalign32*)memPtr = value; } |
| 199 | MEM_STATIC void MEM_write64(void* memPtr, U64 value) { *(unalign64*)memPtr = value; } |
| 200 | |
| 201 | #else |
| 202 | |
| 203 | /* default method, safe and standard. |
| 204 | can sometimes prove slower */ |
| 205 | |
| 206 | MEM_STATIC U16 MEM_read16(const void* memPtr) |
| 207 | { |
| 208 | U16 val; ZSTD_memcpy(&val, memPtr, sizeof(val)); return val; |
| 209 | } |
| 210 | |
| 211 | MEM_STATIC U32 MEM_read32(const void* memPtr) |
| 212 | { |
| 213 | U32 val; ZSTD_memcpy(&val, memPtr, sizeof(val)); return val; |
| 214 | } |
| 215 | |
| 216 | MEM_STATIC U64 MEM_read64(const void* memPtr) |
| 217 | { |
| 218 | U64 val; ZSTD_memcpy(&val, memPtr, sizeof(val)); return val; |
| 219 | } |
| 220 | |
| 221 | MEM_STATIC size_t MEM_readST(const void* memPtr) |
| 222 | { |
| 223 | size_t val; ZSTD_memcpy(&val, memPtr, sizeof(val)); return val; |
| 224 | } |
| 225 | |
| 226 | MEM_STATIC void MEM_write16(void* memPtr, U16 value) |
| 227 | { |
| 228 | ZSTD_memcpy(memPtr, &value, sizeof(value)); |
| 229 | } |
| 230 | |
| 231 | MEM_STATIC void MEM_write32(void* memPtr, U32 value) |
| 232 | { |
| 233 | ZSTD_memcpy(memPtr, &value, sizeof(value)); |
| 234 | } |
| 235 | |
| 236 | MEM_STATIC void MEM_write64(void* memPtr, U64 value) |
| 237 | { |
| 238 | ZSTD_memcpy(memPtr, &value, sizeof(value)); |
| 239 | } |
| 240 | |
| 241 | #endif /* MEM_FORCE_MEMORY_ACCESS */ |
| 242 | |
| 243 | MEM_STATIC U32 MEM_swap32_fallback(U32 in) |
| 244 | { |
| 245 | return ((in << 24) & 0xff000000 ) | |
| 246 | ((in << 8) & 0x00ff0000 ) | |
| 247 | ((in >> 8) & 0x0000ff00 ) | |
| 248 | ((in >> 24) & 0x000000ff ); |
| 249 | } |
| 250 | |
| 251 | MEM_STATIC U32 MEM_swap32(U32 in) |
| 252 | { |
| 253 | #if defined(_MSC_VER) /* Visual Studio */ |
| 254 | return _byteswap_ulong(in); |
| 255 | #elif (defined (__GNUC__) && (__GNUC__ * 100 + __GNUC_MINOR__ >= 403)) \ |
| 256 | || (defined(__clang__) && __has_builtin(__builtin_bswap32)) |
| 257 | return __builtin_bswap32(in); |
| 258 | #else |
| 259 | return MEM_swap32_fallback(in); |
| 260 | #endif |
| 261 | } |
| 262 | |
| 263 | MEM_STATIC U64 MEM_swap64_fallback(U64 in) |
| 264 | { |
| 265 | return ((in << 56) & 0xff00000000000000ULL) | |
| 266 | ((in << 40) & 0x00ff000000000000ULL) | |
| 267 | ((in << 24) & 0x0000ff0000000000ULL) | |
| 268 | ((in << 8) & 0x000000ff00000000ULL) | |
| 269 | ((in >> 8) & 0x00000000ff000000ULL) | |
| 270 | ((in >> 24) & 0x0000000000ff0000ULL) | |
| 271 | ((in >> 40) & 0x000000000000ff00ULL) | |
| 272 | ((in >> 56) & 0x00000000000000ffULL); |
| 273 | } |
| 274 | |
| 275 | MEM_STATIC U64 MEM_swap64(U64 in) |
| 276 | { |
| 277 | #if defined(_MSC_VER) /* Visual Studio */ |
| 278 | return _byteswap_uint64(in); |
| 279 | #elif (defined (__GNUC__) && (__GNUC__ * 100 + __GNUC_MINOR__ >= 403)) \ |
| 280 | || (defined(__clang__) && __has_builtin(__builtin_bswap64)) |
| 281 | return __builtin_bswap64(in); |
| 282 | #else |
| 283 | return MEM_swap64_fallback(in); |
| 284 | #endif |
| 285 | } |
| 286 | |
| 287 | MEM_STATIC size_t MEM_swapST(size_t in) |
| 288 | { |
| 289 | if (MEM_32bits()) |
| 290 | return (size_t)MEM_swap32((U32)in); |
| 291 | else |
| 292 | return (size_t)MEM_swap64((U64)in); |
| 293 | } |
| 294 | |
| 295 | /*=== Little endian r/w ===*/ |
| 296 | |
| 297 | MEM_STATIC U16 MEM_readLE16(const void* memPtr) |
| 298 | { |
| 299 | if (MEM_isLittleEndian()) |
| 300 | return MEM_read16(memPtr); |
| 301 | else { |
| 302 | const BYTE* p = (const BYTE*)memPtr; |
| 303 | return (U16)(p[0] + (p[1]<<8)); |
| 304 | } |
| 305 | } |
| 306 | |
| 307 | MEM_STATIC void MEM_writeLE16(void* memPtr, U16 val) |
| 308 | { |
| 309 | if (MEM_isLittleEndian()) { |
| 310 | MEM_write16(memPtr, val); |
| 311 | } else { |
| 312 | BYTE* p = (BYTE*)memPtr; |
| 313 | p[0] = (BYTE)val; |
| 314 | p[1] = (BYTE)(val>>8); |
| 315 | } |
| 316 | } |
| 317 | |
| 318 | MEM_STATIC U32 MEM_readLE24(const void* memPtr) |
| 319 | { |
| 320 | return (U32)MEM_readLE16(memPtr) + ((U32)(((const BYTE*)memPtr)[2]) << 16); |
| 321 | } |
| 322 | |
| 323 | MEM_STATIC void MEM_writeLE24(void* memPtr, U32 val) |
| 324 | { |
| 325 | MEM_writeLE16(memPtr, (U16)val); |
| 326 | ((BYTE*)memPtr)[2] = (BYTE)(val>>16); |
| 327 | } |
| 328 | |
| 329 | MEM_STATIC U32 MEM_readLE32(const void* memPtr) |
| 330 | { |
| 331 | if (MEM_isLittleEndian()) |
| 332 | return MEM_read32(memPtr); |
| 333 | else |
| 334 | return MEM_swap32(MEM_read32(memPtr)); |
| 335 | } |
| 336 | |
| 337 | MEM_STATIC void MEM_writeLE32(void* memPtr, U32 val32) |
| 338 | { |
| 339 | if (MEM_isLittleEndian()) |
| 340 | MEM_write32(memPtr, val32); |
| 341 | else |
| 342 | MEM_write32(memPtr, MEM_swap32(val32)); |
| 343 | } |
| 344 | |
| 345 | MEM_STATIC U64 MEM_readLE64(const void* memPtr) |
| 346 | { |
| 347 | if (MEM_isLittleEndian()) |
| 348 | return MEM_read64(memPtr); |
| 349 | else |
| 350 | return MEM_swap64(MEM_read64(memPtr)); |
| 351 | } |
| 352 | |
| 353 | MEM_STATIC void MEM_writeLE64(void* memPtr, U64 val64) |
| 354 | { |
| 355 | if (MEM_isLittleEndian()) |
| 356 | MEM_write64(memPtr, val64); |
| 357 | else |
| 358 | MEM_write64(memPtr, MEM_swap64(val64)); |
| 359 | } |
| 360 | |
| 361 | MEM_STATIC size_t MEM_readLEST(const void* memPtr) |
| 362 | { |
| 363 | if (MEM_32bits()) |
| 364 | return (size_t)MEM_readLE32(memPtr); |
| 365 | else |
| 366 | return (size_t)MEM_readLE64(memPtr); |
| 367 | } |
| 368 | |
| 369 | MEM_STATIC void MEM_writeLEST(void* memPtr, size_t val) |
| 370 | { |
| 371 | if (MEM_32bits()) |
| 372 | MEM_writeLE32(memPtr, (U32)val); |
| 373 | else |
| 374 | MEM_writeLE64(memPtr, (U64)val); |
| 375 | } |
| 376 | |
| 377 | /*=== Big endian r/w ===*/ |
| 378 | |
| 379 | MEM_STATIC U32 MEM_readBE32(const void* memPtr) |
| 380 | { |
| 381 | if (MEM_isLittleEndian()) |
| 382 | return MEM_swap32(MEM_read32(memPtr)); |
| 383 | else |
| 384 | return MEM_read32(memPtr); |
| 385 | } |
| 386 | |
| 387 | MEM_STATIC void MEM_writeBE32(void* memPtr, U32 val32) |
| 388 | { |
| 389 | if (MEM_isLittleEndian()) |
| 390 | MEM_write32(memPtr, MEM_swap32(val32)); |
| 391 | else |
| 392 | MEM_write32(memPtr, val32); |
| 393 | } |
| 394 | |
| 395 | MEM_STATIC U64 MEM_readBE64(const void* memPtr) |
| 396 | { |
| 397 | if (MEM_isLittleEndian()) |
| 398 | return MEM_swap64(MEM_read64(memPtr)); |
| 399 | else |
| 400 | return MEM_read64(memPtr); |
| 401 | } |
| 402 | |
| 403 | MEM_STATIC void MEM_writeBE64(void* memPtr, U64 val64) |
| 404 | { |
| 405 | if (MEM_isLittleEndian()) |
| 406 | MEM_write64(memPtr, MEM_swap64(val64)); |
| 407 | else |
| 408 | MEM_write64(memPtr, val64); |
| 409 | } |
| 410 | |
| 411 | MEM_STATIC size_t MEM_readBEST(const void* memPtr) |
| 412 | { |
| 413 | if (MEM_32bits()) |
| 414 | return (size_t)MEM_readBE32(memPtr); |
| 415 | else |
| 416 | return (size_t)MEM_readBE64(memPtr); |
| 417 | } |
| 418 | |
| 419 | MEM_STATIC void MEM_writeBEST(void* memPtr, size_t val) |
| 420 | { |
| 421 | if (MEM_32bits()) |
| 422 | MEM_writeBE32(memPtr, (U32)val); |
| 423 | else |
| 424 | MEM_writeBE64(memPtr, (U64)val); |
| 425 | } |
| 426 | |
| 427 | /* code only tested on 32 and 64 bits systems */ |
| 428 | MEM_STATIC void MEM_check(void) { DEBUG_STATIC_ASSERT((sizeof(size_t)==4) || (sizeof(size_t)==8)); } |
| 429 | |
| 430 | |
| 431 | #if defined (__cplusplus) |
| 432 | } |
| 433 | #endif |
| 434 | |
| 435 | #endif /* MEM_H_MODULE */ |