mem.h
380 lines
| 11.8 KiB
| text/x-c
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CLexer
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r37513 | /* | ||
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r30434 | * Copyright (c) 2016-present, Yann Collet, Facebook, Inc. | ||
* All rights reserved. | ||||
* | ||||
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r37513 | * 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. | ||||
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r30434 | */ | ||
#ifndef MEM_H_MODULE | ||||
#define MEM_H_MODULE | ||||
#if defined (__cplusplus) | ||||
extern "C" { | ||||
#endif | ||||
/*-**************************************** | ||||
* Dependencies | ||||
******************************************/ | ||||
#include <stddef.h> /* size_t, ptrdiff_t */ | ||||
#include <string.h> /* memcpy */ | ||||
/*-**************************************** | ||||
* Compiler specifics | ||||
******************************************/ | ||||
#if defined(_MSC_VER) /* Visual Studio */ | ||||
# include <stdlib.h> /* _byteswap_ulong */ | ||||
# include <intrin.h> /* _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 | ||||
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r42237 | #ifndef __has_builtin | ||
# define __has_builtin(x) 0 /* compat. with non-clang compilers */ | ||||
#endif | ||||
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r30434 | /* code only tested on 32 and 64 bits systems */ | ||
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r30895 | #define MEM_STATIC_ASSERT(c) { enum { MEM_static_assert = 1/(int)(!!(c)) }; } | ||
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r30434 | MEM_STATIC void MEM_check(void) { MEM_STATIC_ASSERT((sizeof(size_t)==4) || (sizeof(size_t)==8)); } | ||
/*-************************************************************** | ||||
* Basic Types | ||||
*****************************************************************/ | ||||
#if !defined (__VMS) && (defined (__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */) ) | ||||
# include <stdint.h> | ||||
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r37513 | 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; | ||||
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r30434 | #else | ||
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r40157 | # include <limits.h> | ||
#if CHAR_BIT != 8 | ||||
# error "this implementation requires char to be exactly 8-bit type" | ||||
#endif | ||||
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r30822 | typedef unsigned char BYTE; | ||
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r40157 | #if USHRT_MAX != 65535 | ||
# error "this implementation requires short to be exactly 16-bit type" | ||||
#endif | ||||
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r30434 | typedef unsigned short U16; | ||
typedef signed short S16; | ||||
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r40157 | #if UINT_MAX != 4294967295 | ||
# error "this implementation requires int to be exactly 32-bit type" | ||||
#endif | ||||
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r30434 | typedef unsigned int U32; | ||
typedef signed int S32; | ||||
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r40157 | /* note : there are no limits defined for long long type in C90. | ||
* limits exist in C99, however, in such case, <stdint.h> is preferred */ | ||||
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r30434 | typedef unsigned long long U64; | ||
typedef signed long long S64; | ||||
#endif | ||||
/*-************************************************************** | ||||
* Memory I/O | ||||
*****************************************************************/ | ||||
/* 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. | ||||
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r37513 | * Method 1 : `__packed` statement. It depends on compiler extension (i.e., not portable). | ||
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r30434 | * 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. | ||||
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r37513 | * In some circumstances, it's the only known way to get the most performance (i.e. GCC + ARMv6) | ||
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r30434 | * 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(__GNUC__) && ( defined(__ARM_ARCH_6__) || defined(__ARM_ARCH_6J__) || defined(__ARM_ARCH_6K__) || defined(__ARM_ARCH_6Z__) || defined(__ARM_ARCH_6ZK__) || defined(__ARM_ARCH_6T2__) ) | ||||
# define MEM_FORCE_MEMORY_ACCESS 2 | ||||
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r37513 | # elif defined(__INTEL_COMPILER) || defined(__GNUC__) | ||
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r30434 | # 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; } | ||||
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r37513 | MEM_STATIC size_t MEM_readST(const void* memPtr) { return *(const size_t*) memPtr; } | ||
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r30434 | |||
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)) | ||||
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r37513 | __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; | ||||
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r30434 | __pragma( pack(pop) ) | ||
#else | ||||
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r37513 | 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; | ||||
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r30434 | #endif | ||
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r37513 | 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; } | ||||
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r30434 | |||
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r37513 | 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; } | ||||
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r30434 | |||
#else | ||||
/* default method, safe and standard. | ||||
can sometimes prove slower */ | ||||
MEM_STATIC U16 MEM_read16(const void* memPtr) | ||||
{ | ||||
U16 val; memcpy(&val, memPtr, sizeof(val)); return val; | ||||
} | ||||
MEM_STATIC U32 MEM_read32(const void* memPtr) | ||||
{ | ||||
U32 val; memcpy(&val, memPtr, sizeof(val)); return val; | ||||
} | ||||
MEM_STATIC U64 MEM_read64(const void* memPtr) | ||||
{ | ||||
U64 val; memcpy(&val, memPtr, sizeof(val)); return val; | ||||
} | ||||
MEM_STATIC size_t MEM_readST(const void* memPtr) | ||||
{ | ||||
size_t val; memcpy(&val, memPtr, sizeof(val)); return val; | ||||
} | ||||
MEM_STATIC void MEM_write16(void* memPtr, U16 value) | ||||
{ | ||||
memcpy(memPtr, &value, sizeof(value)); | ||||
} | ||||
MEM_STATIC void MEM_write32(void* memPtr, U32 value) | ||||
{ | ||||
memcpy(memPtr, &value, sizeof(value)); | ||||
} | ||||
MEM_STATIC void MEM_write64(void* memPtr, U64 value) | ||||
{ | ||||
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); | ||||
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r42237 | #elif (defined (__GNUC__) && (__GNUC__ * 100 + __GNUC_MINOR__ >= 403)) \ | ||
|| (defined(__clang__) && __has_builtin(__builtin_bswap32)) | ||||
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r30434 | 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); | ||||
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r42237 | #elif (defined (__GNUC__) && (__GNUC__ * 100 + __GNUC_MINOR__ >= 403)) \ | ||
|| (defined(__clang__) && __has_builtin(__builtin_bswap64)) | ||||
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r30434 | 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 MEM_readLE16(memPtr) + (((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); | ||||
} | ||||
#if defined (__cplusplus) | ||||
} | ||||
#endif | ||||
#endif /* MEM_H_MODULE */ | ||||