1 /* 2 * Copyright (c) 2016-present, Yann Collet, Facebook, Inc. 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 ZSTD_COMPILER_H 12 #define ZSTD_COMPILER_H 13 14 /*-******************************************************* 15 * Compiler specifics 16 *********************************************************/ 17 /* force inlining */ 18 19 #if !defined(ZSTD_NO_INLINE) 20 #if defined (__GNUC__) || defined(__cplusplus) || defined(__STDC_VERSION__) && __STDC_VERSION__ >= 199901L /* C99 */ 21 # define INLINE_KEYWORD inline 22 #else 23 # define INLINE_KEYWORD 24 #endif 25 26 #if defined(__GNUC__) 27 # define FORCE_INLINE_ATTR __attribute__((always_inline)) 28 #elif defined(_MSC_VER) 29 # define FORCE_INLINE_ATTR __forceinline 30 #else 31 # define FORCE_INLINE_ATTR 32 #endif 33 34 #else 35 36 #define INLINE_KEYWORD 37 #define FORCE_INLINE_ATTR 38 39 #endif 40 41 /** 42 * FORCE_INLINE_TEMPLATE is used to define C "templates", which take constant 43 * parameters. They must be inlined for the compiler to elimininate the constant 44 * branches. 45 */ 46 #define FORCE_INLINE_TEMPLATE static INLINE_KEYWORD FORCE_INLINE_ATTR 47 /** 48 * HINT_INLINE is used to help the compiler generate better code. It is *not* 49 * used for "templates", so it can be tweaked based on the compilers 50 * performance. 51 * 52 * gcc-4.8 and gcc-4.9 have been shown to benefit from leaving off the 53 * always_inline attribute. 54 * 55 * clang up to 5.0.0 (trunk) benefit tremendously from the always_inline 56 * attribute. 57 */ 58 #if !defined(__clang__) && defined(__GNUC__) && __GNUC__ >= 4 && __GNUC_MINOR__ >= 8 && __GNUC__ < 5 59 # define HINT_INLINE static INLINE_KEYWORD 60 #else 61 # define HINT_INLINE static INLINE_KEYWORD FORCE_INLINE_ATTR 62 #endif 63 64 /* force no inlining */ 65 #ifdef _MSC_VER 66 # define FORCE_NOINLINE static __declspec(noinline) 67 #else 68 # ifdef __GNUC__ 69 # define FORCE_NOINLINE static __attribute__((__noinline__)) 70 # else 71 # define FORCE_NOINLINE static 72 # endif 73 #endif 74 75 /* target attribute */ 76 #ifndef __has_attribute 77 #define __has_attribute(x) 0 /* Compatibility with non-clang compilers. */ 78 #endif 79 #if defined(__GNUC__) 80 # define TARGET_ATTRIBUTE(target) __attribute__((__target__(target))) 81 #else 82 # define TARGET_ATTRIBUTE(target) 83 #endif 84 85 /* Enable runtime BMI2 dispatch based on the CPU. 86 * Enabled for clang & gcc >=4.8 on x86 when BMI2 isn't enabled by default. 87 */ 88 #ifndef DYNAMIC_BMI2 89 #if ((defined(__clang__) && __has_attribute(__target__)) \ 90 || (defined(__GNUC__) \ 91 && (__GNUC__ >= 5 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 8)))) \ 92 && (defined(__x86_64__) || defined(_M_X86)) \ 93 && !defined(__BMI2__) 94 # define DYNAMIC_BMI2 1 95 #else 96 # define DYNAMIC_BMI2 0 97 #endif 98 #endif 99 100 /* prefetch 101 * can be disabled, by declaring NO_PREFETCH build macro */ 102 #if defined(NO_PREFETCH) 103 # define PREFETCH_L1(ptr) (void)(ptr) /* disabled */ 104 # define PREFETCH_L2(ptr) (void)(ptr) /* disabled */ 105 #else 106 # if defined(_MSC_VER) && (defined(_M_X64) || defined(_M_I86)) /* _mm_prefetch() is not defined outside of x86/x64 */ 107 # include <mmintrin.h> /* https://msdn.microsoft.com/fr-fr/library/84szxsww(v=vs.90).aspx */ 108 # define PREFETCH_L1(ptr) _mm_prefetch((const char*)(ptr), _MM_HINT_T0) 109 # define PREFETCH_L2(ptr) _mm_prefetch((const char*)(ptr), _MM_HINT_T1) 110 # elif defined(__GNUC__) && ( (__GNUC__ >= 4) || ( (__GNUC__ == 3) && (__GNUC_MINOR__ >= 1) ) ) 111 # define PREFETCH_L1(ptr) __builtin_prefetch((ptr), 0 /* rw==read */, 3 /* locality */) 112 # define PREFETCH_L2(ptr) __builtin_prefetch((ptr), 0 /* rw==read */, 2 /* locality */) 113 # else 114 # define PREFETCH_L1(ptr) (void)(ptr) /* disabled */ 115 # define PREFETCH_L2(ptr) (void)(ptr) /* disabled */ 116 # endif 117 #endif /* NO_PREFETCH */ 118 119 #define CACHELINE_SIZE 64 120 121 #define PREFETCH_AREA(p, s) { \ 122 const char* const _ptr = (const char*)(p); \ 123 size_t const _size = (size_t)(s); \ 124 size_t _pos; \ 125 for (_pos=0; _pos<_size; _pos+=CACHELINE_SIZE) { \ 126 PREFETCH_L2(_ptr + _pos); \ 127 } \ 128 } 129 130 /* disable warnings */ 131 #ifdef _MSC_VER /* Visual Studio */ 132 # include <intrin.h> /* For Visual 2005 */ 133 # pragma warning(disable : 4100) /* disable: C4100: unreferenced formal parameter */ 134 # pragma warning(disable : 4127) /* disable: C4127: conditional expression is constant */ 135 # pragma warning(disable : 4204) /* disable: C4204: non-constant aggregate initializer */ 136 # pragma warning(disable : 4214) /* disable: C4214: non-int bitfields */ 137 # pragma warning(disable : 4324) /* disable: C4324: padded structure */ 138 #endif 139 140 #endif /* ZSTD_COMPILER_H */ 141