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1 /* |
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2 * Copyright (c) 2016-present, Yann Collet, Facebook, Inc. |
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3 * All rights reserved. |
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4 * |
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5 * This source code is licensed under both the BSD-style license (found in the |
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6 * LICENSE file in the root directory of this source tree) and the GPLv2 (found |
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7 * in the COPYING file in the root directory of this source tree). |
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8 * You may select, at your option, one of the above-listed licenses. |
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9 */ |
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10 |
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11 #ifndef ZSTD_COMPILER_H |
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12 #define ZSTD_COMPILER_H |
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13 |
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14 /*-******************************************************* |
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15 * Compiler specifics |
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16 *********************************************************/ |
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17 /* force inlining */ |
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18 #if defined (__GNUC__) || defined(__cplusplus) || defined(__STDC_VERSION__) && __STDC_VERSION__ >= 199901L /* C99 */ |
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19 # define INLINE_KEYWORD inline |
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20 #else |
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21 # define INLINE_KEYWORD |
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22 #endif |
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23 |
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24 #if defined(__GNUC__) |
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25 # define FORCE_INLINE_ATTR __attribute__((always_inline)) |
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26 #elif defined(_MSC_VER) |
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27 # define FORCE_INLINE_ATTR __forceinline |
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28 #else |
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29 # define FORCE_INLINE_ATTR |
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30 #endif |
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31 |
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32 /** |
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33 * FORCE_INLINE_TEMPLATE is used to define C "templates", which take constant |
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34 * parameters. They must be inlined for the compiler to elimininate the constant |
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35 * branches. |
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36 */ |
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37 #define FORCE_INLINE_TEMPLATE static INLINE_KEYWORD FORCE_INLINE_ATTR |
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38 /** |
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39 * HINT_INLINE is used to help the compiler generate better code. It is *not* |
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40 * used for "templates", so it can be tweaked based on the compilers |
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41 * performance. |
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42 * |
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43 * gcc-4.8 and gcc-4.9 have been shown to benefit from leaving off the |
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44 * always_inline attribute. |
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45 * |
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46 * clang up to 5.0.0 (trunk) benefit tremendously from the always_inline |
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47 * attribute. |
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48 */ |
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49 #if !defined(__clang__) && defined(__GNUC__) && __GNUC__ >= 4 && __GNUC_MINOR__ >= 8 && __GNUC__ < 5 |
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50 # define HINT_INLINE static INLINE_KEYWORD |
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51 #else |
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52 # define HINT_INLINE static INLINE_KEYWORD FORCE_INLINE_ATTR |
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53 #endif |
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54 |
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55 /* force no inlining */ |
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56 #ifdef _MSC_VER |
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57 # define FORCE_NOINLINE static __declspec(noinline) |
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58 #else |
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59 # ifdef __GNUC__ |
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60 # define FORCE_NOINLINE static __attribute__((__noinline__)) |
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61 # else |
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62 # define FORCE_NOINLINE static |
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63 # endif |
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64 #endif |
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65 |
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66 /* target attribute */ |
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67 #ifndef __has_attribute |
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68 #define __has_attribute(x) 0 /* Compatibility with non-clang compilers. */ |
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69 #endif |
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70 #if defined(__GNUC__) |
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71 # define TARGET_ATTRIBUTE(target) __attribute__((__target__(target))) |
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72 #else |
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73 # define TARGET_ATTRIBUTE(target) |
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74 #endif |
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75 |
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76 /* Enable runtime BMI2 dispatch based on the CPU. |
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77 * Enabled for clang & gcc >=4.8 on x86 when BMI2 isn't enabled by default. |
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78 */ |
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79 #ifndef DYNAMIC_BMI2 |
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80 #if (defined(__clang__) && __has_attribute(__target__)) \ |
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81 || (defined(__GNUC__) \ |
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82 && (__GNUC__ >= 5 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 8))) \ |
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83 && (defined(__x86_64__) || defined(_M_X86)) \ |
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84 && !defined(__BMI2__) |
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85 # define DYNAMIC_BMI2 1 |
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86 #else |
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87 # define DYNAMIC_BMI2 0 |
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88 #endif |
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89 #endif |
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90 |
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91 /* prefetch */ |
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92 #if defined(_MSC_VER) && (defined(_M_X64) || defined(_M_I86)) /* _mm_prefetch() is not defined outside of x86/x64 */ |
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93 # include <mmintrin.h> /* https://msdn.microsoft.com/fr-fr/library/84szxsww(v=vs.90).aspx */ |
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94 # define PREFETCH(ptr) _mm_prefetch((const char*)ptr, _MM_HINT_T0) |
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95 #elif defined(__GNUC__) |
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96 # define PREFETCH(ptr) __builtin_prefetch(ptr, 0, 0) |
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97 #else |
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98 # define PREFETCH(ptr) /* disabled */ |
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99 #endif |
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100 |
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101 /* disable warnings */ |
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102 #ifdef _MSC_VER /* Visual Studio */ |
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103 # include <intrin.h> /* For Visual 2005 */ |
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104 # pragma warning(disable : 4100) /* disable: C4100: unreferenced formal parameter */ |
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105 # pragma warning(disable : 4127) /* disable: C4127: conditional expression is constant */ |
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106 # pragma warning(disable : 4204) /* disable: C4204: non-constant aggregate initializer */ |
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107 # pragma warning(disable : 4214) /* disable: C4214: non-int bitfields */ |
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108 # pragma warning(disable : 4324) /* disable: C4324: padded structure */ |
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109 #endif |
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110 |
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111 #endif /* ZSTD_COMPILER_H */ |