xref: /third_party/mesa3d/src/util/compiler.h (revision bf215546)
1/*
2 * Mesa 3-D graphics library
3 *
4 * Copyright (C) 1999-2008  Brian Paul   All Rights Reserved.
5 * Copyright (C) 2009  VMware, Inc.  All Rights Reserved.
6 *
7 * Permission is hereby granted, free of charge, to any person obtaining a
8 * copy of this software and associated documentation files (the "Software"),
9 * to deal in the Software without restriction, including without limitation
10 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
11 * and/or sell copies of the Software, and to permit persons to whom the
12 * Software is furnished to do so, subject to the following conditions:
13 *
14 * The above copyright notice and this permission notice shall be included
15 * in all copies or substantial portions of the Software.
16 *
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
18 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
20 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
21 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
22 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
23 * OTHER DEALINGS IN THE SOFTWARE.
24 */
25
26
27/**
28 * \file compiler.h
29 * Compiler-related stuff.
30 */
31
32
33#ifndef COMPILER_H
34#define COMPILER_H
35
36
37#include <assert.h>
38
39#include "util/macros.h"
40
41
42/**
43 * Either define MESA_BIG_ENDIAN or MESA_LITTLE_ENDIAN, and CPU_TO_LE32.
44 * Do not use these unless absolutely necessary!
45 * Try to use a runtime test instead.
46 * For now, only used by some DRI hardware drivers for color/texel packing.
47 */
48#if defined(BYTE_ORDER) && defined(BIG_ENDIAN) && BYTE_ORDER == BIG_ENDIAN
49#if defined(__linux__)
50#include <byteswap.h>
51#define CPU_TO_LE32( x )	bswap_32( x )
52#elif defined(__APPLE__)
53#include <CoreFoundation/CFByteOrder.h>
54#define CPU_TO_LE32( x )	CFSwapInt32HostToLittle( x )
55#elif defined(__OpenBSD__)
56#include <sys/types.h>
57#define CPU_TO_LE32( x )	htole32( x )
58#else /*__linux__ */
59#include <sys/endian.h>
60#define CPU_TO_LE32( x )	bswap32( x )
61#endif /*__linux__*/
62#define MESA_BIG_ENDIAN 1
63#else
64#define CPU_TO_LE32( x )	( x )
65#define MESA_LITTLE_ENDIAN 1
66#endif
67#define LE32_TO_CPU( x )	CPU_TO_LE32( x )
68
69
70
71#define IEEE_ONE 0x3f800000
72
73#ifndef __has_attribute
74#  define __has_attribute(x) 0
75#endif
76
77#if defined(__has_cpp_attribute) && defined(__clang__)
78/* We do not do the same trick as __has_attribute because parsing
79 * clang::fallthrough in the preprocessor fails in GCC. */
80#  define HAS_CLANG_FALLTHROUGH  __has_cpp_attribute(clang::fallthrough)
81#else
82#  define HAS_CLANG_FALLTHROUGH 0
83#endif
84
85#if __cplusplus >= 201703L || __STDC_VERSION__ > 201710L
86/* Standard C++17/C23 attribute */
87#define FALLTHROUGH [[fallthrough]]
88#elif HAS_CLANG_FALLTHROUGH
89/* Clang++ specific */
90#define FALLTHROUGH [[clang::fallthrough]]
91#elif __has_attribute(fallthrough)
92/* Non-standard but supported by at least gcc and clang */
93#define FALLTHROUGH __attribute__((fallthrough))
94#else
95#define FALLTHROUGH do { } while(0)
96#endif
97
98#endif /* COMPILER_H */
99