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Diffstat (limited to '')
| -rw-r--r-- | third_party/zstd/lib/common/mem.h | 426 |
1 files changed, 426 insertions, 0 deletions
diff --git a/third_party/zstd/lib/common/mem.h b/third_party/zstd/lib/common/mem.h new file mode 100644 index 0000000000..096f4be519 --- /dev/null +++ b/third_party/zstd/lib/common/mem.h @@ -0,0 +1,426 @@ +/* + * Copyright (c) Meta Platforms, Inc. and affiliates. + * All rights reserved. + * + * This source code is licensed under both the BSD-style license (found in the + * LICENSE file in the root directory of this source tree) and the GPLv2 (found + * in the COPYING file in the root directory of this source tree). + * You may select, at your option, one of the above-listed licenses. + */ + +#ifndef MEM_H_MODULE +#define MEM_H_MODULE + +#if defined (__cplusplus) +extern "C" { +#endif + +/*-**************************************** +* Dependencies +******************************************/ +#include <stddef.h> /* size_t, ptrdiff_t */ +#include "compiler.h" /* __has_builtin */ +#include "debug.h" /* DEBUG_STATIC_ASSERT */ +#include "zstd_deps.h" /* ZSTD_memcpy */ + + +/*-**************************************** +* Compiler specifics +******************************************/ +#if defined(_MSC_VER) /* Visual Studio */ +# include <stdlib.h> /* _byteswap_ulong */ +# include <intrin.h> /* _byteswap_* */ +#endif + +/*-************************************************************** +* Basic Types +*****************************************************************/ +#if !defined (__VMS) && (defined (__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */) ) +# if defined(_AIX) +# include <inttypes.h> +# else +# include <stdint.h> /* intptr_t */ +# endif + typedef uint8_t BYTE; + typedef uint8_t U8; + typedef int8_t S8; + typedef uint16_t U16; + typedef int16_t S16; + typedef uint32_t U32; + typedef int32_t S32; + typedef uint64_t U64; + typedef int64_t S64; +#else +# include <limits.h> +#if CHAR_BIT != 8 +# error "this implementation requires char to be exactly 8-bit type" +#endif + typedef unsigned char BYTE; + typedef unsigned char U8; + typedef signed char S8; +#if USHRT_MAX != 65535 +# error "this implementation requires short to be exactly 16-bit type" +#endif + typedef unsigned short U16; + typedef signed short S16; +#if UINT_MAX != 4294967295 +# error "this implementation requires int to be exactly 32-bit type" +#endif + typedef unsigned int U32; + typedef signed int S32; +/* note : there are no limits defined for long long type in C90. + * limits exist in C99, however, in such case, <stdint.h> is preferred */ + typedef unsigned long long U64; + typedef signed long long S64; +#endif + + +/*-************************************************************** +* Memory I/O API +*****************************************************************/ +/*=== Static platform detection ===*/ +MEM_STATIC unsigned MEM_32bits(void); +MEM_STATIC unsigned MEM_64bits(void); +MEM_STATIC unsigned MEM_isLittleEndian(void); + +/*=== Native unaligned read/write ===*/ +MEM_STATIC U16 MEM_read16(const void* memPtr); +MEM_STATIC U32 MEM_read32(const void* memPtr); +MEM_STATIC U64 MEM_read64(const void* memPtr); +MEM_STATIC size_t MEM_readST(const void* memPtr); + +MEM_STATIC void MEM_write16(void* memPtr, U16 value); +MEM_STATIC void MEM_write32(void* memPtr, U32 value); +MEM_STATIC void MEM_write64(void* memPtr, U64 value); + +/*=== Little endian unaligned read/write ===*/ +MEM_STATIC U16 MEM_readLE16(const void* memPtr); +MEM_STATIC U32 MEM_readLE24(const void* memPtr); +MEM_STATIC U32 MEM_readLE32(const void* memPtr); +MEM_STATIC U64 MEM_readLE64(const void* memPtr); +MEM_STATIC size_t MEM_readLEST(const void* memPtr); + +MEM_STATIC void MEM_writeLE16(void* memPtr, U16 val); +MEM_STATIC void MEM_writeLE24(void* memPtr, U32 val); +MEM_STATIC void MEM_writeLE32(void* memPtr, U32 val32); +MEM_STATIC void MEM_writeLE64(void* memPtr, U64 val64); +MEM_STATIC void MEM_writeLEST(void* memPtr, size_t val); + +/*=== Big endian unaligned read/write ===*/ +MEM_STATIC U32 MEM_readBE32(const void* memPtr); +MEM_STATIC U64 MEM_readBE64(const void* memPtr); +MEM_STATIC size_t MEM_readBEST(const void* memPtr); + +MEM_STATIC void MEM_writeBE32(void* memPtr, U32 val32); +MEM_STATIC void MEM_writeBE64(void* memPtr, U64 val64); +MEM_STATIC void MEM_writeBEST(void* memPtr, size_t val); + +/*=== Byteswap ===*/ +MEM_STATIC U32 MEM_swap32(U32 in); +MEM_STATIC U64 MEM_swap64(U64 in); +MEM_STATIC size_t MEM_swapST(size_t in); + + +/*-************************************************************** +* Memory I/O Implementation +*****************************************************************/ +/* MEM_FORCE_MEMORY_ACCESS : For accessing unaligned memory: + * Method 0 : always use `memcpy()`. Safe and portable. + * Method 1 : Use compiler extension to set unaligned access. + * Method 2 : direct access. This method is portable but violate C standard. + * It can generate buggy code on targets depending on alignment. + * Default : method 1 if supported, else method 0 + */ +#ifndef MEM_FORCE_MEMORY_ACCESS /* can be defined externally, on command line for example */ +# ifdef __GNUC__ +# define MEM_FORCE_MEMORY_ACCESS 1 +# endif +#endif + +MEM_STATIC unsigned MEM_32bits(void) { return sizeof(size_t)==4; } +MEM_STATIC unsigned MEM_64bits(void) { return sizeof(size_t)==8; } + +MEM_STATIC unsigned MEM_isLittleEndian(void) +{ +#if defined(__BYTE_ORDER__) && defined(__ORDER_LITTLE_ENDIAN__) && (__BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__) + return 1; +#elif defined(__BYTE_ORDER__) && defined(__ORDER_BIG_ENDIAN__) && (__BYTE_ORDER__ == __ORDER_BIG_ENDIAN__) + return 0; +#elif defined(__clang__) && __LITTLE_ENDIAN__ + return 1; +#elif defined(__clang__) && __BIG_ENDIAN__ + return 0; +#elif defined(_MSC_VER) && (_M_AMD64 || _M_IX86) + return 1; +#elif defined(__DMC__) && defined(_M_IX86) + return 1; +#else + const union { U32 u; BYTE c[4]; } one = { 1 }; /* don't use static : performance detrimental */ + return one.c[0]; +#endif +} + +#if defined(MEM_FORCE_MEMORY_ACCESS) && (MEM_FORCE_MEMORY_ACCESS==2) + +/* violates C standard, by lying on structure alignment. +Only use if no other choice to achieve best performance on target platform */ +MEM_STATIC U16 MEM_read16(const void* memPtr) { return *(const U16*) memPtr; } +MEM_STATIC U32 MEM_read32(const void* memPtr) { return *(const U32*) memPtr; } +MEM_STATIC U64 MEM_read64(const void* memPtr) { return *(const U64*) memPtr; } +MEM_STATIC size_t MEM_readST(const void* memPtr) { return *(const size_t*) memPtr; } + +MEM_STATIC void MEM_write16(void* memPtr, U16 value) { *(U16*)memPtr = value; } +MEM_STATIC void MEM_write32(void* memPtr, U32 value) { *(U32*)memPtr = value; } +MEM_STATIC void MEM_write64(void* memPtr, U64 value) { *(U64*)memPtr = value; } + +#elif defined(MEM_FORCE_MEMORY_ACCESS) && (MEM_FORCE_MEMORY_ACCESS==1) + +typedef __attribute__((aligned(1))) U16 unalign16; +typedef __attribute__((aligned(1))) U32 unalign32; +typedef __attribute__((aligned(1))) U64 unalign64; +typedef __attribute__((aligned(1))) size_t unalignArch; + +MEM_STATIC U16 MEM_read16(const void* ptr) { return *(const unalign16*)ptr; } +MEM_STATIC U32 MEM_read32(const void* ptr) { return *(const unalign32*)ptr; } +MEM_STATIC U64 MEM_read64(const void* ptr) { return *(const unalign64*)ptr; } +MEM_STATIC size_t MEM_readST(const void* ptr) { return *(const unalignArch*)ptr; } + +MEM_STATIC void MEM_write16(void* memPtr, U16 value) { *(unalign16*)memPtr = value; } +MEM_STATIC void MEM_write32(void* memPtr, U32 value) { *(unalign32*)memPtr = value; } +MEM_STATIC void MEM_write64(void* memPtr, U64 value) { *(unalign64*)memPtr = value; } + +#else + +/* default method, safe and standard. + can sometimes prove slower */ + +MEM_STATIC U16 MEM_read16(const void* memPtr) +{ + U16 val; ZSTD_memcpy(&val, memPtr, sizeof(val)); return val; +} + +MEM_STATIC U32 MEM_read32(const void* memPtr) +{ + U32 val; ZSTD_memcpy(&val, memPtr, sizeof(val)); return val; +} + +MEM_STATIC U64 MEM_read64(const void* memPtr) +{ + U64 val; ZSTD_memcpy(&val, memPtr, sizeof(val)); return val; +} + +MEM_STATIC size_t MEM_readST(const void* memPtr) +{ + size_t val; ZSTD_memcpy(&val, memPtr, sizeof(val)); return val; +} + +MEM_STATIC void MEM_write16(void* memPtr, U16 value) +{ + ZSTD_memcpy(memPtr, &value, sizeof(value)); +} + +MEM_STATIC void MEM_write32(void* memPtr, U32 value) +{ + ZSTD_memcpy(memPtr, &value, sizeof(value)); +} + +MEM_STATIC void MEM_write64(void* memPtr, U64 value) +{ + ZSTD_memcpy(memPtr, &value, sizeof(value)); +} + +#endif /* MEM_FORCE_MEMORY_ACCESS */ + +MEM_STATIC U32 MEM_swap32_fallback(U32 in) +{ + return ((in << 24) & 0xff000000 ) | + ((in << 8) & 0x00ff0000 ) | + ((in >> 8) & 0x0000ff00 ) | + ((in >> 24) & 0x000000ff ); +} + +MEM_STATIC U32 MEM_swap32(U32 in) +{ +#if defined(_MSC_VER) /* Visual Studio */ + return _byteswap_ulong(in); +#elif (defined (__GNUC__) && (__GNUC__ * 100 + __GNUC_MINOR__ >= 403)) \ + || (defined(__clang__) && __has_builtin(__builtin_bswap32)) + return __builtin_bswap32(in); +#else + return MEM_swap32_fallback(in); +#endif +} + +MEM_STATIC U64 MEM_swap64_fallback(U64 in) +{ + return ((in << 56) & 0xff00000000000000ULL) | + ((in << 40) & 0x00ff000000000000ULL) | + ((in << 24) & 0x0000ff0000000000ULL) | + ((in << 8) & 0x000000ff00000000ULL) | + ((in >> 8) & 0x00000000ff000000ULL) | + ((in >> 24) & 0x0000000000ff0000ULL) | + ((in >> 40) & 0x000000000000ff00ULL) | + ((in >> 56) & 0x00000000000000ffULL); +} + +MEM_STATIC U64 MEM_swap64(U64 in) +{ +#if defined(_MSC_VER) /* Visual Studio */ + return _byteswap_uint64(in); +#elif (defined (__GNUC__) && (__GNUC__ * 100 + __GNUC_MINOR__ >= 403)) \ + || (defined(__clang__) && __has_builtin(__builtin_bswap64)) + return __builtin_bswap64(in); +#else + return MEM_swap64_fallback(in); +#endif +} + +MEM_STATIC size_t MEM_swapST(size_t in) +{ + if (MEM_32bits()) + return (size_t)MEM_swap32((U32)in); + else + return (size_t)MEM_swap64((U64)in); +} + +/*=== Little endian r/w ===*/ + +MEM_STATIC U16 MEM_readLE16(const void* memPtr) +{ + if (MEM_isLittleEndian()) + return MEM_read16(memPtr); + else { + const BYTE* p = (const BYTE*)memPtr; + return (U16)(p[0] + (p[1]<<8)); + } +} + +MEM_STATIC void MEM_writeLE16(void* memPtr, U16 val) +{ + if (MEM_isLittleEndian()) { + MEM_write16(memPtr, val); + } else { + BYTE* p = (BYTE*)memPtr; + p[0] = (BYTE)val; + p[1] = (BYTE)(val>>8); + } +} + +MEM_STATIC U32 MEM_readLE24(const void* memPtr) +{ + return (U32)MEM_readLE16(memPtr) + ((U32)(((const BYTE*)memPtr)[2]) << 16); +} + +MEM_STATIC void MEM_writeLE24(void* memPtr, U32 val) +{ + MEM_writeLE16(memPtr, (U16)val); + ((BYTE*)memPtr)[2] = (BYTE)(val>>16); +} + +MEM_STATIC U32 MEM_readLE32(const void* memPtr) +{ + if (MEM_isLittleEndian()) + return MEM_read32(memPtr); + else + return MEM_swap32(MEM_read32(memPtr)); +} + +MEM_STATIC void MEM_writeLE32(void* memPtr, U32 val32) +{ + if (MEM_isLittleEndian()) + MEM_write32(memPtr, val32); + else + MEM_write32(memPtr, MEM_swap32(val32)); +} + +MEM_STATIC U64 MEM_readLE64(const void* memPtr) +{ + if (MEM_isLittleEndian()) + return MEM_read64(memPtr); + else + return MEM_swap64(MEM_read64(memPtr)); +} + +MEM_STATIC void MEM_writeLE64(void* memPtr, U64 val64) +{ + if (MEM_isLittleEndian()) + MEM_write64(memPtr, val64); + else + MEM_write64(memPtr, MEM_swap64(val64)); +} + +MEM_STATIC size_t MEM_readLEST(const void* memPtr) +{ + if (MEM_32bits()) + return (size_t)MEM_readLE32(memPtr); + else + return (size_t)MEM_readLE64(memPtr); +} + +MEM_STATIC void MEM_writeLEST(void* memPtr, size_t val) +{ + if (MEM_32bits()) + MEM_writeLE32(memPtr, (U32)val); + else + MEM_writeLE64(memPtr, (U64)val); +} + +/*=== Big endian r/w ===*/ + +MEM_STATIC U32 MEM_readBE32(const void* memPtr) +{ + if (MEM_isLittleEndian()) + return MEM_swap32(MEM_read32(memPtr)); + else + return MEM_read32(memPtr); +} + +MEM_STATIC void MEM_writeBE32(void* memPtr, U32 val32) +{ + if (MEM_isLittleEndian()) + MEM_write32(memPtr, MEM_swap32(val32)); + else + MEM_write32(memPtr, val32); +} + +MEM_STATIC U64 MEM_readBE64(const void* memPtr) +{ + if (MEM_isLittleEndian()) + return MEM_swap64(MEM_read64(memPtr)); + else + return MEM_read64(memPtr); +} + +MEM_STATIC void MEM_writeBE64(void* memPtr, U64 val64) +{ + if (MEM_isLittleEndian()) + MEM_write64(memPtr, MEM_swap64(val64)); + else + MEM_write64(memPtr, val64); +} + +MEM_STATIC size_t MEM_readBEST(const void* memPtr) +{ + if (MEM_32bits()) + return (size_t)MEM_readBE32(memPtr); + else + return (size_t)MEM_readBE64(memPtr); +} + +MEM_STATIC void MEM_writeBEST(void* memPtr, size_t val) +{ + if (MEM_32bits()) + MEM_writeBE32(memPtr, (U32)val); + else + MEM_writeBE64(memPtr, (U64)val); +} + +/* code only tested on 32 and 64 bits systems */ +MEM_STATIC void MEM_check(void) { DEBUG_STATIC_ASSERT((sizeof(size_t)==4) || (sizeof(size_t)==8)); } + + +#if defined (__cplusplus) +} +#endif + +#endif /* MEM_H_MODULE */ |