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1c353010 DG |
1 | #ifndef _URCU_COMPILER_H |
2 | #define _URCU_COMPILER_H | |
3 | ||
4 | /* | |
5 | * compiler.h | |
6 | * | |
7 | * Compiler definitions. | |
8 | * | |
9 | * Copyright (c) 2009 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> | |
10 | * | |
11 | * Permission is hereby granted, free of charge, to any person obtaining a copy | |
12 | * of this software and associated documentation files (the "Software"), to deal | |
13 | * in the Software without restriction, including without limitation the rights | |
14 | * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell | |
15 | * copies of the Software, and to permit persons to whom the Software is | |
16 | * furnished to do so, subject to the following conditions: | |
17 | * | |
18 | * The above copyright notice and this permission notice shall be included in | |
19 | * all copies or substantial portions of the Software. | |
20 | */ | |
21 | ||
22 | #include <stddef.h> /* for offsetof */ | |
23 | ||
24 | #define caa_likely(x) __builtin_expect(!!(x), 1) | |
25 | #define caa_unlikely(x) __builtin_expect(!!(x), 0) | |
26 | ||
27 | #define cmm_barrier() __asm__ __volatile__ ("" : : : "memory") | |
28 | ||
29 | /* | |
30 | * Instruct the compiler to perform only a single access to a variable | |
31 | * (prohibits merging and refetching). The compiler is also forbidden to reorder | |
32 | * successive instances of CMM_ACCESS_ONCE(), but only when the compiler is aware of | |
33 | * particular ordering. Compiler ordering can be ensured, for example, by | |
34 | * putting two CMM_ACCESS_ONCE() in separate C statements. | |
35 | * | |
36 | * This macro does absolutely -nothing- to prevent the CPU from reordering, | |
37 | * merging, or refetching absolutely anything at any time. Its main intended | |
38 | * use is to mediate communication between process-level code and irq/NMI | |
39 | * handlers, all running on the same CPU. | |
40 | */ | |
41 | #define CMM_ACCESS_ONCE(x) (*(__volatile__ __typeof__(x) *)&(x)) | |
42 | ||
43 | #ifndef caa_max | |
44 | #define caa_max(a,b) ((a)>(b)?(a):(b)) | |
45 | #endif | |
46 | ||
47 | #ifndef caa_min | |
48 | #define caa_min(a,b) ((a)<(b)?(a):(b)) | |
49 | #endif | |
50 | ||
51 | #if defined(__SIZEOF_LONG__) | |
52 | #define CAA_BITS_PER_LONG (__SIZEOF_LONG__ * 8) | |
53 | #elif defined(_LP64) | |
54 | #define CAA_BITS_PER_LONG 64 | |
55 | #else | |
56 | #define CAA_BITS_PER_LONG 32 | |
57 | #endif | |
58 | ||
59 | /* | |
60 | * caa_container_of - Get the address of an object containing a field. | |
61 | * | |
62 | * @ptr: pointer to the field. | |
63 | * @type: type of the object. | |
64 | * @member: name of the field within the object. | |
65 | */ | |
66 | #define caa_container_of(ptr, type, member) \ | |
67 | ({ \ | |
68 | const __typeof__(((type *) NULL)->member) * __ptr = (ptr); \ | |
69 | (type *)((char *)__ptr - offsetof(type, member)); \ | |
70 | }) | |
71 | ||
72 | #define CAA_BUILD_BUG_ON_ZERO(cond) (sizeof(struct { int:-!!(cond); })) | |
73 | #define CAA_BUILD_BUG_ON(cond) ((void)CAA_BUILD_BUG_ON_ZERO(cond)) | |
74 | ||
75 | /* | |
76 | * __rcu is an annotation that documents RCU pointer accesses that need | |
77 | * to be protected by a read-side critical section. Eventually, a static | |
78 | * checker will be able to use this annotation to detect incorrect RCU | |
79 | * usage. | |
80 | */ | |
81 | #define __rcu | |
82 | ||
83 | #ifdef __cplusplus | |
84 | #define URCU_FORCE_CAST(type, arg) (reinterpret_cast<type>(arg)) | |
85 | #else | |
86 | #define URCU_FORCE_CAST(type, arg) ((type) (arg)) | |
87 | #endif | |
88 | ||
89 | #define caa_is_signed_type(type) (((type) (-1)) < 0) | |
90 | ||
91 | #define caa_cast_long_keep_sign(v) \ | |
92 | (caa_is_signed_type(__typeof__(v)) ? (long) (v) : (unsigned long) (v)) | |
93 | ||
94 | #if defined (__GNUC__) \ | |
95 | && ((__GNUC_MAJOR__ == 4) && (__GNUC_MINOR__ >= 5) \ | |
96 | || __GNUC_MAJOR__ >= 5) | |
97 | #define CDS_DEPRECATED(msg) \ | |
98 | __attribute__((deprecated(msg))) | |
99 | #else | |
100 | #define CDS_DEPRECATED(msg) \ | |
101 | __attribute__((deprecated)) | |
102 | #endif | |
103 | ||
104 | #define CAA_ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0])) | |
105 | ||
106 | #endif /* _URCU_COMPILER_H */ |