blob: 3a7553c3807eeeb8f750fa9a7993df3d7704ac19 [file] [log] [blame]
Yann Collet32fb4072017-08-18 16:52:05 -07001/*
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).
Yann Collet3128e032017-09-08 00:09:23 -07008 * You may select, at your option, one of the above-listed licenses.
Yann Collet32fb4072017-08-18 16:52:05 -07009 */
10
Nick Terrell565e9252017-08-14 17:20:50 -070011#ifndef ZSTD_COMPILER_H
12#define ZSTD_COMPILER_H
13
14/*-*******************************************************
15* Compiler specifics
16*********************************************************/
17/* force inlining */
18#if defined (__GNUC__) || defined(__cplusplus) || defined(__STDC_VERSION__) && __STDC_VERSION__ >= 199901L /* C99 */
19# define INLINE_KEYWORD inline
20#else
21# define INLINE_KEYWORD
22#endif
23
24#if defined(__GNUC__)
25# define FORCE_INLINE_ATTR __attribute__((always_inline))
26#elif defined(_MSC_VER)
27# define FORCE_INLINE_ATTR __forceinline
28#else
29# define FORCE_INLINE_ATTR
30#endif
31
32/**
33 * FORCE_INLINE_TEMPLATE is used to define C "templates", which take constant
34 * parameters. They must be inlined for the compiler to elimininate the constant
35 * branches.
36 */
37#define FORCE_INLINE_TEMPLATE static INLINE_KEYWORD FORCE_INLINE_ATTR
38/**
39 * HINT_INLINE is used to help the compiler generate better code. It is *not*
40 * used for "templates", so it can be tweaked based on the compilers
41 * performance.
42 *
43 * gcc-4.8 and gcc-4.9 have been shown to benefit from leaving off the
44 * always_inline attribute.
45 *
46 * clang up to 5.0.0 (trunk) benefit tremendously from the always_inline
47 * attribute.
48 */
49#if !defined(__clang__) && defined(__GNUC__) && __GNUC__ >= 4 && __GNUC_MINOR__ >= 8 && __GNUC__ < 5
50# define HINT_INLINE static INLINE_KEYWORD
51#else
52# define HINT_INLINE static INLINE_KEYWORD FORCE_INLINE_ATTR
53#endif
54
55/* force no inlining */
56#ifdef _MSC_VER
57# define FORCE_NOINLINE static __declspec(noinline)
58#else
59# ifdef __GNUC__
60# define FORCE_NOINLINE static __attribute__((__noinline__))
61# else
62# define FORCE_NOINLINE static
63# endif
64#endif
65
66/* prefetch */
67#if defined(_MSC_VER) && (defined(_M_X64) || defined(_M_I86)) /* _mm_prefetch() is not defined outside of x86/x64 */
68# include <mmintrin.h> /* https://msdn.microsoft.com/fr-fr/library/84szxsww(v=vs.90).aspx */
69# define PREFETCH(ptr) _mm_prefetch((const char*)ptr, _MM_HINT_T0)
70#elif defined(__GNUC__)
71# define PREFETCH(ptr) __builtin_prefetch(ptr, 0, 0)
72#else
73# define PREFETCH(ptr) /* disabled */
74#endif
75
76/* disable warnings */
77#ifdef _MSC_VER /* Visual Studio */
78# include <intrin.h> /* For Visual 2005 */
79# pragma warning(disable : 4100) /* disable: C4100: unreferenced formal parameter */
80# pragma warning(disable : 4127) /* disable: C4127: conditional expression is constant */
81# pragma warning(disable : 4204) /* disable: C4204: non-constant aggregate initializer */
82# pragma warning(disable : 4214) /* disable: C4214: non-int bitfields */
83# pragma warning(disable : 4324) /* disable: C4324: padded structure */
84#endif
85
86#endif /* ZSTD_COMPILER_H */