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__) || defined(__ICCARM__) 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 eliminate 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 /* UNUSED_ATTR tells the compiler it is okay if the function is unused. */ 65 #if defined(__GNUC__) 66 # define UNUSED_ATTR __attribute__((unused)) 67 #else 68 # define UNUSED_ATTR 69 #endif 70 71 /* force no inlining */ 72 #ifdef _MSC_VER 73 # define FORCE_NOINLINE static __declspec(noinline) 74 #else 75 # if defined(__GNUC__) || defined(__ICCARM__) 76 # define FORCE_NOINLINE static __attribute__((__noinline__)) 77 # else 78 # define FORCE_NOINLINE static 79 # endif 80 #endif 81 82 /* target attribute */ 83 #ifndef __has_attribute 84 #define __has_attribute(x) 0 /* Compatibility with non-clang compilers. */ 85 #endif 86 #if defined(__GNUC__) || defined(__ICCARM__) 87 # define TARGET_ATTRIBUTE(target) __attribute__((__target__(target))) 88 #else 89 # define TARGET_ATTRIBUTE(target) 90 #endif 91 92 /* Enable runtime BMI2 dispatch based on the CPU. 93 * Enabled for clang & gcc >=4.8 on x86 when BMI2 isn't enabled by default. 94 */ 95 #ifndef DYNAMIC_BMI2 96 #if ((defined(__clang__) && __has_attribute(__target__)) \ 97 || (defined(__GNUC__) \ 98 && (__GNUC__ >= 5 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 8)))) \ 99 && (defined(__x86_64__) || defined(_M_X86)) \ 100 && !defined(__BMI2__) 101 # define DYNAMIC_BMI2 1 102 #else 103 # define DYNAMIC_BMI2 0 104 #endif 105 #endif 106 107 /* prefetch 108 * can be disabled, by declaring NO_PREFETCH build macro */ 109 #if defined(NO_PREFETCH) 110 # define PREFETCH_L1(ptr) (void)(ptr) /* disabled */ 111 # define PREFETCH_L2(ptr) (void)(ptr) /* disabled */ 112 #else 113 # if defined(_MSC_VER) && (defined(_M_X64) || defined(_M_I86)) /* _mm_prefetch() is not defined outside of x86/x64 */ 114 # include <mmintrin.h> /* https://msdn.microsoft.com/fr-fr/library/84szxsww(v=vs.90).aspx */ 115 # define PREFETCH_L1(ptr) _mm_prefetch((const char*)(ptr), _MM_HINT_T0) 116 # define PREFETCH_L2(ptr) _mm_prefetch((const char*)(ptr), _MM_HINT_T1) 117 # elif defined(__GNUC__) && ( (__GNUC__ >= 4) || ( (__GNUC__ == 3) && (__GNUC_MINOR__ >= 1) ) ) 118 # define PREFETCH_L1(ptr) __builtin_prefetch((ptr), 0 /* rw==read */, 3 /* locality */) 119 # define PREFETCH_L2(ptr) __builtin_prefetch((ptr), 0 /* rw==read */, 2 /* locality */) 120 # else 121 # define PREFETCH_L1(ptr) (void)(ptr) /* disabled */ 122 # define PREFETCH_L2(ptr) (void)(ptr) /* disabled */ 123 # endif 124 #endif /* NO_PREFETCH */ 125 126 #define CACHELINE_SIZE 64 127 128 #define PREFETCH_AREA(p, s) { \ 129 const char* const _ptr = (const char*)(p); \ 130 size_t const _size = (size_t)(s); \ 131 size_t _pos; \ 132 for (_pos=0; _pos<_size; _pos+=CACHELINE_SIZE) { \ 133 PREFETCH_L2(_ptr + _pos); \ 134 } \ 135 } 136 137 /* vectorization 138 * older GCC (pre gcc-4.3 picked as the cutoff) uses a different syntax */ 139 #if !defined(__clang__) && defined(__GNUC__) && __GNUC__ > 5 140 # if (__GNUC__ == 4 && __GNUC_MINOR__ > 3) || (__GNUC__ >= 5) 141 # define DONT_VECTORIZE __attribute__((optimize("no-tree-vectorize"))) 142 # else 143 # define DONT_VECTORIZE _Pragma("GCC optimize(\"no-tree-vectorize\")") 144 # endif 145 #else 146 # define DONT_VECTORIZE 147 #endif 148 149 /* disable warnings */ 150 #ifdef _MSC_VER /* Visual Studio */ 151 # include <intrin.h> /* For Visual 2005 */ 152 # pragma warning(disable : 4100) /* disable: C4100: unreferenced formal parameter */ 153 # pragma warning(disable : 4127) /* disable: C4127: conditional expression is constant */ 154 # pragma warning(disable : 4204) /* disable: C4204: non-constant aggregate initializer */ 155 # pragma warning(disable : 4214) /* disable: C4214: non-int bitfields */ 156 # pragma warning(disable : 4324) /* disable: C4324: padded structure */ 157 #endif 158 159 #endif /* ZSTD_COMPILER_H */ 160