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 #include "c99_compat.h" /* inline, __func__, etc. */
42 
43 
44 /**
45  * Either define MESA_BIG_ENDIAN or MESA_LITTLE_ENDIAN, and CPU_TO_LE32.
46  * Do not use these unless absolutely necessary!
47  * Try to use a runtime test instead.
48  * For now, only used by some DRI hardware drivers for color/texel packing.
49  */
50 #if defined(BYTE_ORDER) && defined(BIG_ENDIAN) && BYTE_ORDER == BIG_ENDIAN
51 #if defined(__linux__)
52 #include <byteswap.h>
53 #define CPU_TO_LE32( x )	bswap_32( x )
54 #elif defined(__APPLE__)
55 #include <CoreFoundation/CFByteOrder.h>
56 #define CPU_TO_LE32( x )	CFSwapInt32HostToLittle( x )
57 #elif defined(__OpenBSD__)
58 #include <sys/types.h>
59 #define CPU_TO_LE32( x )	htole32( x )
60 #else /*__linux__ */
61 #include <sys/endian.h>
62 #define CPU_TO_LE32( x )	bswap32( x )
63 #endif /*__linux__*/
64 #define MESA_BIG_ENDIAN 1
65 #else
66 #define CPU_TO_LE32( x )	( x )
67 #define MESA_LITTLE_ENDIAN 1
68 #endif
69 #define LE32_TO_CPU( x )	CPU_TO_LE32( x )
70 
71 
72 
73 #define IEEE_ONE 0x3f800000
74 
75 #ifndef __has_attribute
76 #  define __has_attribute(x) 0
77 #endif
78 
79 #if defined(__has_cpp_attribute) && defined(__clang__)
80 /* We do not do the same trick as __has_attribute because parsing
81  * clang::fallthrough in the preprocessor fails in GCC. */
82 #  define HAS_CLANG_FALLTHROUGH  __has_cpp_attribute(clang::fallthrough)
83 #else
84 #  define HAS_CLANG_FALLTHROUGH 0
85 #endif
86 
87 #if __cplusplus >= 201703L || __STDC_VERSION__ > 201710L
88 /* Standard C++17/C23 attribute */
89 #define FALLTHROUGH [[fallthrough]]
90 #elif HAS_CLANG_FALLTHROUGH
91 /* Clang++ specific */
92 #define FALLTHROUGH [[clang::fallthrough]]
93 #elif __has_attribute(fallthrough)
94 /* Non-standard but supported by at least gcc and clang */
95 #define FALLTHROUGH __attribute__((fallthrough))
96 #else
97 #define FALLTHROUGH do { } while(0)
98 #endif
99 
100 #endif /* COMPILER_H */
101