ViewVC Help
View File | Revision Log | Show Annotations | Download File
/cvs/libecb/ecb.h
(Generate patch)

Comparing libecb/ecb.h (file contents):
Revision 1.3 by root, Thu May 26 16:57:04 2011 UTC vs.
Revision 1.10 by root, Thu May 26 17:57:32 2011 UTC

1/* 1/*
2 * libecb 2 * libecb
3 * 3 *
4 * Copyright (©) 2009-2011 Marc Alexander Lehmann 4 * Copyright (©) 2009-2011 Marc Alexander Lehmann
5 * Copyright (©) 2011 Emanuele Giaquinta
5 * All rights reserved. 6 * All rights reserved.
6 * 7 *
7 * Redistribution and use in source and binary forms, with or without modifica- 8 * Redistribution and use in source and binary forms, with or without modifica-
8 * tion, are permitted provided that the following conditions are met: 9 * tion, are permitted provided that the following conditions are met:
9 * 10 *
… …
27 */ 28 */
28 29
29#ifndef ECB_H 30#ifndef ECB_H
30#define ECB_H 31#define ECB_H
31 32
33#include <inttypes.h>
34
32#define ECB_GCC_VERSION(major,minor) (__GNUC__ > (major) || (__GNUC__ == (major) && __GNUC_MINOR__ >= (minor))) 35#define ECB_GCC_VERSION(major,minor) (__GNUC__ > (major) || (__GNUC__ == (major) && __GNUC_MINOR__ >= (minor)))
33 36
37#ifndef __cplusplus
38# if __STDC_VERSION__ >= 199901L
39# define ECB_INLINE inline
40typedef _Bool ecb_bool;
41# else
42# define ECB_INLINE inline /* yeah! */
43typedef int ecb_bool;
44# endif
45#endif
46
47#define ECB_CONCAT_(a, b) a ## b
48#define ECB_CONCAT(a, b) ECB_CONCAT_(a, b)
49#define ECB_STRINGIFY_(a) # a
50#define ECB_STRINGIFY(a) ECB_STRINGIFY_(a)
51
34#define ECB_HEADER_INLINE static inline 52#define ECB_HEADER_INLINE static ECB_INLINE
35 53
36#if ECB_GCC_VERSION(3,1) 54#if ECB_GCC_VERSION(3,1)
37# define ecb_attribute(attrlist) __attribute__(attrlist) 55# define ecb_attribute(attrlist) __attribute__(attrlist)
38# define ecb_is_constant(c) __builtin_constant_p (c) 56# define ecb_is_constant(c) __builtin_constant_p (c)
39# define ecb_expect(expr,value) __builtin_expect ((expr),(value)) 57# define ecb_expect(expr,value) __builtin_expect ((expr),(value))
… …
55#define ecb_noinline ecb_attribute ((noinline)) 73#define ecb_noinline ecb_attribute ((noinline))
56#define ecb_noreturn ecb_attribute ((noreturn)) 74#define ecb_noreturn ecb_attribute ((noreturn))
57#define ecb_unused ecb_attribute ((unused)) 75#define ecb_unused ecb_attribute ((unused))
58#define ecb_const ecb_attribute ((const)) 76#define ecb_const ecb_attribute ((const))
59#define ecb_pure ecb_attribute ((pure)) 77#define ecb_pure ecb_attribute ((pure))
60#define ecb_hot ecb_attribute ((hot)) // 4.3 78#define ecb_hot ecb_attribute ((hot)) /* 4.3 */
61#define ecb_cold ecb_attribute ((cold)) // 4.3 79#define ecb_cold ecb_attribute ((cold)) /* 4.3 */
62 80
63#if ECB_GCC_VERSION(4,5) 81#if ECB_GCC_VERSION(4,5)
64# define ecb_unreachable() __builtin_unreachable () 82# define ecb_unreachable() __builtin_unreachable ()
65#else 83#else
66 /* this seems to work fine, but gcc always emits a warning for it :/ */ 84/* this seems to work fine, but gcc always emits a warning for it :/ */
67 ECB_HEADER_INLINE void ecb_unreachable () ecb_attribute ((noreturn)); 85ECB_HEADER_INLINE void ecb_unreachable () ecb_attribute ((noreturn));
68 ECB_HEADER_INLINE void ecb_unreachable () { } 86ECB_HEADER_INLINE void ecb_unreachable () { }
69#endif 87#endif
70 88
71/* put into ifs if you are very sure that the expression */ 89/* put into ifs if you are very sure that the expression */
72/* is mostly true or mosty false. note that these return */ 90/* is mostly true or mosty false. note that these return */
73/* booleans, not the expression. */ 91/* booleans, not the expression. */
74#define ecb_expect_false(expr) ecb_expect ((expr) ? 1 : 0, 0) 92#define ecb_unlikely(expr) ecb_expect ((expr) ? 1 : 0, 0)
75#define ecb_expect_true(expr) ecb_expect ((expr) ? 1 : 0, 1) 93#define ecb_likely(expr) ecb_expect ((expr) ? 1 : 0, 1)
76 94
77/* try to tell the compiler that some condition is definitely true */ 95/* try to tell the compiler that some condition is definitely true */
78#define ecb_assume(cond) do { if (!(cond)) unreachable (); } while (0) 96#define ecb_assume(cond) do { if (!(cond)) unreachable (); } while (0)
79 97
80/* count trailing zero bits and count # of one bits */ 98/* count trailing zero bits and count # of one bits */
81#if ECB_GCC_VERSION(3,4) 99#if ECB_GCC_VERSION(3,4)
82ECB_HEADER_INLINE int ecb_ctz (unsigned int x) { return __builtin_ctz (x); } 100ECB_HEADER_INLINE int ecb_ctz32 (uint32_t x) { return __builtin_ctz (x); }
83ECB_HEADER_INLINE int ecb_popcount (unsigned int x) { return __builtin_popcount (x); } 101ECB_HEADER_INLINE int ecb_popcount32 (uint32_t x) { return __builtin_popcount (x); }
84#else 102#else
85ECB_HEADER_INLINE 103ECB_HEADER_INLINE
86ecb_ctz (unsigned int x) ecb_const 104ecb_ctz32 (uint32_t x) ecb_const
87{ 105{
88 int r = 0; 106 int r = 0;
89 107
90 x &= -x; // this isolates the lowest bit 108 x &= -x; /* this isolates the lowest bit */
91 109
92 if (x & 0xaaaaaaaa) r += 1; 110 if (x & 0xaaaaaaaa) r += 1;
93 if (x & 0xcccccccc) r += 2; 111 if (x & 0xcccccccc) r += 2;
94 if (x & 0xf0f0f0f0) r += 4; 112 if (x & 0xf0f0f0f0) r += 4;
95 if (x & 0xff00ff00) r += 8; 113 if (x & 0xff00ff00) r += 8;
… …
97 115
98 return r; 116 return r;
99} 117}
100 118
101ECB_HEADER_INLINE 119ECB_HEADER_INLINE
102ecb_popcount (unsigned int x) ecb_const 120ecb_popcount32 (uint32_t x) ecb_const
103{ 121{
104 x -= (x >> 1) & 0x55555555; 122 x -= (x >> 1) & 0x55555555;
105 x = ((x >> 2) & 0x33333333) + (x & 0x33333333); 123 x = ((x >> 2) & 0x33333333) + (x & 0x33333333);
106 x = ((x >> 4) + x) & 0x0f0f0f0f; 124 x = ((x >> 4) + x) & 0x0f0f0f0f;
107 x *= 0x01010101; 125 x *= 0x01010101;
… …
115{ 133{
116 const uint32_t u = 0x11223344; 134 const uint32_t u = 0x11223344;
117 return *(unsigned char *)&u; 135 return *(unsigned char *)&u;
118} 136}
119 137
120ECB_HEADER_INLINE bool ecb_big_endian () ecb_const { return ecb_byteorder_helper () == 0x11; }; 138ECB_HEADER_INLINE ecb_bool ecb_big_endian () ecb_const { return ecb_byteorder_helper () == 0x11; };
121ECB_HEADER_INLINE bool ecb_network () ecb_const { return big_endian (); };
122ECB_HEADER_INLINE bool ecb_little_endian () ecb_const { return ecb_byteorder_helper () == 0x44; }; 139ECB_HEADER_INLINE ecb_bool ecb_little_endian () ecb_const { return ecb_byteorder_helper () == 0x44; };
123ECB_HEADER_INLINE bool ecb_vax () ecb_const { return little_endian (); };
124 140
141#if ecb_cplusplus_does_not_suck
142// does not work for local types (http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2657.htm)
143template<typename T, int N>
144static inline int ecb_array_length (const T (&arr)[N])
145{
146 return N;
147}
148#else
149#define ecb_array_length(name) (sizeof (name) / sizeof (name [0]))
150#endif
151
152ECB_INLINE uint32_t
153ecb_rotr32 (uint32_t x, unsigned int count)
154{
155 return (x << (32 - count)) | (x >> count);
156}
157
158ECB_INLINE uint32_t
159ecb_rotl32 (uint32_t x, unsigned int count)
160{
161 return (x >> (32 - count)) | (x << count);
162}
163
164#if ECB_GCC_VERSION(4,3)
165# define ecb_bswap32(x) __builtin_bswap32 (x)
166#else
167ECB_GCC_VERSION uint32_t
168ecb_bswap32 (uint32_t x)
169{
170 return (x >> 24)
171 | ((x >> 8) & 0x0000ff00)
172 | ((x << 8) & 0x00ff0000)
173 | (x << 24);
174}
175#endif
125 176
126#endif 177#endif
127 178

Diff Legend

– Removed lines
+ Added lines
< Changed lines
> Changed lines