#ifndef MEM_H_MODULE #define MEM_H_MODULE /* * Copyright (c) Yann Collet, Facebook, Inc. * 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. */ #if defined (__cplusplus) extern "C" { #endif /*-**************************************** * Dependencies ******************************************/ #include /* 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 /* _byteswap_ulong */ # include /* _byteswap_* */ #endif #if defined(__GNUC__) # define MEM_STATIC static __inline __attribute__((unused)) #elif defined (__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */) # define MEM_STATIC static inline #elif defined(_MSC_VER) # define MEM_STATIC static __inline #else # define MEM_STATIC static /* this version may generate warnings for unused static functions; disable the relevant warning */ #endif /*-************************************************************** * Basic Types *****************************************************************/ #if !defined (__VMS) && (defined (__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */) ) # if defined(_AIX) # include # else # include /* intptr_t */ # endif typedef uint8_t BYTE; 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 #if CHAR_BIT != 8 # error "this implementation requires char to be exactly 8-bit type" #endif typedef unsigned char BYTE; #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, 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 : * By default, access to unaligned memory is controlled by `memcpy()`, which is safe and portable. * Unfortunately, on some target/compiler combinations, the generated assembly is sub-optimal. * The below switch allow to select different access method for improved performance. * Method 0 (default) : use `memcpy()`. Safe and portable. * Method 1 : `__packed` statement. It depends on compiler extension (i.e., not portable). * This method is safe if your compiler supports it, and *generally* as fast or faster than `memcpy`. * Method 2 : direct access. This method is portable but violate C standard. * It can generate buggy code on targets depending on alignment. * In some circumstances, it's the only known way to get the most performance (i.e. GCC + ARMv6) * See http://fastcompression.blogspot.fr/2015/08/accessing-unaligned-memory.html for details. * Prefer these methods in priority order (0 > 1 > 2) */ #ifndef MEM_FORCE_MEMORY_ACCESS /* can be defined externally, on command line for example */ # if defined(__INTEL_COMPILER) || defined(__GNUC__) || defined(__ICCARM__) # 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) { const union { U32 u; BYTE c[4]; } one = { 1 }; /* don't use static : performance detrimental */ return one.c[0]; } #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) /* __pack instructions are safer, but compiler specific, hence potentially problematic for some compilers */ /* currently only defined for gcc and icc */ #if defined(_MSC_VER) || (defined(__INTEL_COMPILER) && defined(WIN32)) __pragma( pack(push, 1) ) typedef struct { U16 v; } unalign16; typedef struct { U32 v; } unalign32; typedef struct { U64 v; } unalign64; typedef struct { size_t v; } unalignArch; __pragma( pack(pop) ) #else typedef struct { U16 v; } __attribute__((packed)) unalign16; typedef struct { U32 v; } __attribute__((packed)) unalign32; typedef struct { U64 v; } __attribute__((packed)) unalign64; typedef struct { size_t v; } __attribute__((packed)) unalignArch; #endif MEM_STATIC U16 MEM_read16(const void* ptr) { return ((const unalign16*)ptr)->v; } MEM_STATIC U32 MEM_read32(const void* ptr) { return ((const unalign32*)ptr)->v; } MEM_STATIC U64 MEM_read64(const void* ptr) { return ((const unalign64*)ptr)->v; } MEM_STATIC size_t MEM_readST(const void* ptr) { return ((const unalignArch*)ptr)->v; } MEM_STATIC void MEM_write16(void* memPtr, U16 value) { ((unalign16*)memPtr)->v = value; } MEM_STATIC void MEM_write32(void* memPtr, U32 value) { ((unalign32*)memPtr)->v = value; } MEM_STATIC void MEM_write64(void* memPtr, U64 value) { ((unalign64*)memPtr)->v = 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(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 ((in << 24) & 0xff000000 ) | ((in << 8) & 0x00ff0000 ) | ((in >> 8) & 0x0000ff00 ) | ((in >> 24) & 0x000000ff ); #endif } 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 ((in << 56) & 0xff00000000000000ULL) | ((in << 40) & 0x00ff000000000000ULL) | ((in << 24) & 0x0000ff0000000000ULL) | ((in << 8) & 0x000000ff00000000ULL) | ((in >> 8) & 0x00000000ff000000ULL) | ((in >> 24) & 0x0000000000ff0000ULL) | ((in >> 40) & 0x000000000000ff00ULL) | ((in >> 56) & 0x00000000000000ffULL); #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 */