ReactOS  0.4.15-dev-5112-g22d8c0f
compiler.h
Go to the documentation of this file.
1 /*
2  * Copyright (c) 2016-2020, 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(__STRICT_ANSI__)) || 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 
46 #define FORCE_INLINE_TEMPLATE static INLINE_KEYWORD FORCE_INLINE_ATTR
47 
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(__aarch64__)
118 # define PREFETCH_L1(ptr) __asm__ __volatile__("prfm pldl1keep, %0" ::"Q"(*(ptr)))
119 # define PREFETCH_L2(ptr) __asm__ __volatile__("prfm pldl2keep, %0" ::"Q"(*(ptr)))
120 # elif defined(__GNUC__) && ( (__GNUC__ >= 4) || ( (__GNUC__ == 3) && (__GNUC_MINOR__ >= 1) ) )
121 # define PREFETCH_L1(ptr) __builtin_prefetch((ptr), 0 /* rw==read */, 3 /* locality */)
122 # define PREFETCH_L2(ptr) __builtin_prefetch((ptr), 0 /* rw==read */, 2 /* locality */)
123 # else
124 # define PREFETCH_L1(ptr) (void)(ptr) /* disabled */
125 # define PREFETCH_L2(ptr) (void)(ptr) /* disabled */
126 # endif
127 #endif /* NO_PREFETCH */
128 
129 #define CACHELINE_SIZE 64
130 
131 #define PREFETCH_AREA(p, s) { \
132  const char* const _ptr = (const char*)(p); \
133  size_t const _size = (size_t)(s); \
134  size_t _pos; \
135  for (_pos=0; _pos<_size; _pos+=CACHELINE_SIZE) { \
136  PREFETCH_L2(_ptr + _pos); \
137  } \
138 }
139 
140 /* vectorization
141  * older GCC (pre gcc-4.3 picked as the cutoff) uses a different syntax */
142 #if !defined(__INTEL_COMPILER) && !defined(__clang__) && defined(__GNUC__)
143 # if (__GNUC__ == 4 && __GNUC_MINOR__ > 3) || (__GNUC__ >= 5)
144 # define DONT_VECTORIZE __attribute__((optimize("no-tree-vectorize")))
145 # else
146 # define DONT_VECTORIZE _Pragma("GCC optimize(\"no-tree-vectorize\")")
147 # endif
148 #else
149 # define DONT_VECTORIZE
150 #endif
151 
152 /* Tell the compiler that a branch is likely or unlikely.
153  * Only use these macros if it causes the compiler to generate better code.
154  * If you can remove a LIKELY/UNLIKELY annotation without speed changes in gcc
155  * and clang, please do.
156  */
157 #if defined(__GNUC__)
158 #define LIKELY(x) (__builtin_expect((x), 1))
159 #define UNLIKELY(x) (__builtin_expect((x), 0))
160 #else
161 #define LIKELY(x) (x)
162 #define UNLIKELY(x) (x)
163 #endif
164 
165 /* disable warnings */
166 #ifdef _MSC_VER /* Visual Studio */
167 # include <intrin.h> /* For Visual 2005 */
168 # pragma warning(disable : 4100) /* disable: C4100: unreferenced formal parameter */
169 # pragma warning(disable : 4127) /* disable: C4127: conditional expression is constant */
170 # pragma warning(disable : 4204) /* disable: C4204: non-constant aggregate initializer */
171 # pragma warning(disable : 4214) /* disable: C4214: non-int bitfields */
172 # pragma warning(disable : 4324) /* disable: C4324: padded structure */
173 #endif
174 
175 #endif /* ZSTD_COMPILER_H */