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Revision: 1.11
Committed: Thu May 26 18:00:42 2011 UTC (13 years, 1 month ago) by root
Content type: text/plain
Branch: MAIN
Changes since 1.10: +2 -2 lines
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# Content
1 /*
2 * libecb
3 *
4 * Copyright (©) 2009-2011 Marc Alexander Lehmann
5 * Copyright (©) 2011 Emanuele Giaquinta
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without modifica-
9 * tion, are permitted provided that the following conditions are met:
10 *
11 * 1. Redistributions of source code must retain the above copyright notice,
12 * this list of conditions and the following disclaimer.
13 *
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
19 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MER-
20 * CHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
21 * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPE-
22 * CIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
23 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
24 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
25 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTH-
26 * ERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
27 * OF THE POSSIBILITY OF SUCH DAMAGE.
28 */
29
30 #ifndef ECB_H
31 #define ECB_H
32
33 #include <inttypes.h>
34
35 #define ECB_GCC_VERSION(major,minor) (__GNUC__ > (major) || (__GNUC__ == (major) && __GNUC_MINOR__ >= (minor)))
36
37 #ifndef __cplusplus
38 # if __STDC_VERSION__ >= 199901L
39 # define ECB_INLINE inline
40 typedef _Bool ecb_bool;
41 # else
42 # define ECB_INLINE inline /* yeah! */
43 typedef 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
52 #define ECB_HEADER_INLINE static ECB_INLINE
53
54 #if ECB_GCC_VERSION(3,1)
55 # define ecb_attribute(attrlist) __attribute__(attrlist)
56 # define ecb_is_constant(c) __builtin_constant_p (c)
57 # define ecb_expect(expr,value) __builtin_expect ((expr),(value))
58 # define ecb_prefetch(addr,rw,locality) __builtin_prefetch (addr, rw, locality)
59 #else
60 # define ecb_attribute(attrlist)
61 # define ecb_is_constant(c) 0
62 # define ecb_expect(expr,value) (expr)
63 # define ecb_prefetch(addr,rw,locality)
64 #endif
65
66 /* no emulation for ecb_decltype */
67 #if ECB_GCC_VERSION(4,5)
68 # define ecb_decltype(x) __decltype(x)
69 #elif ECB_GCC_VERSION(3,0)
70 # define ecb_decltype(x) typeof(x)
71 #endif
72
73 #define ecb_noinline ecb_attribute ((noinline))
74 #define ecb_noreturn ecb_attribute ((noreturn))
75 #define ecb_unused ecb_attribute ((unused))
76 #define ecb_const ecb_attribute ((const))
77 #define ecb_pure ecb_attribute ((pure))
78 #define ecb_hot ecb_attribute ((hot)) /* 4.3 */
79 #define ecb_cold ecb_attribute ((cold)) /* 4.3 */
80
81 #if ECB_GCC_VERSION(4,5)
82 # define ecb_unreachable() __builtin_unreachable ()
83 #else
84 /* this seems to work fine, but gcc always emits a warning for it :/ */
85 ECB_HEADER_INLINE void ecb_unreachable () ecb_attribute ((noreturn));
86 ECB_HEADER_INLINE void ecb_unreachable () { }
87 #endif
88
89 /* put into ifs if you are very sure that the expression */
90 /* is mostly true or mosty false. note that these return */
91 /* booleans, not the expression. */
92 #define ecb_unlikely(expr) ecb_expect (!!(expr), 0)
93 #define ecb_likely(expr) ecb_expect (!!(expr), 1)
94
95 /* try to tell the compiler that some condition is definitely true */
96 #define ecb_assume(cond) do { if (!(cond)) unreachable (); } while (0)
97
98 /* count trailing zero bits and count # of one bits */
99 #if ECB_GCC_VERSION(3,4)
100 ECB_HEADER_INLINE int ecb_ctz32 (uint32_t x) { return __builtin_ctz (x); }
101 ECB_HEADER_INLINE int ecb_popcount32 (uint32_t x) { return __builtin_popcount (x); }
102 #else
103 ECB_HEADER_INLINE
104 ecb_ctz32 (uint32_t x) ecb_const
105 {
106 int r = 0;
107
108 x &= -x; /* this isolates the lowest bit */
109
110 if (x & 0xaaaaaaaa) r += 1;
111 if (x & 0xcccccccc) r += 2;
112 if (x & 0xf0f0f0f0) r += 4;
113 if (x & 0xff00ff00) r += 8;
114 if (x & 0xffff0000) r += 16;
115
116 return r;
117 }
118
119 ECB_HEADER_INLINE
120 ecb_popcount32 (uint32_t x) ecb_const
121 {
122 x -= (x >> 1) & 0x55555555;
123 x = ((x >> 2) & 0x33333333) + (x & 0x33333333);
124 x = ((x >> 4) + x) & 0x0f0f0f0f;
125 x *= 0x01010101;
126
127 return x >> 24;
128 }
129 #endif
130
131 ECB_HEADER_INLINE unsigned char
132 ecb_byteorder_helper () ecb_const
133 {
134 const uint32_t u = 0x11223344;
135 return *(unsigned char *)&u;
136 }
137
138 ECB_HEADER_INLINE ecb_bool ecb_big_endian () ecb_const { return ecb_byteorder_helper () == 0x11; };
139 ECB_HEADER_INLINE ecb_bool ecb_little_endian () ecb_const { return ecb_byteorder_helper () == 0x44; };
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)
143 template<typename T, int N>
144 static 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
152 ECB_INLINE uint32_t
153 ecb_rotr32 (uint32_t x, unsigned int count)
154 {
155 return (x << (32 - count)) | (x >> count);
156 }
157
158 ECB_INLINE uint32_t
159 ecb_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
167 ECB_GCC_VERSION uint32_t
168 ecb_bswap32 (uint32_t x)
169 {
170 return (x >> 24)
171 | ((x >> 8) & 0x0000ff00)
172 | ((x << 8) & 0x00ff0000)
173 | (x << 24);
174 }
175 #endif
176
177 #endif
178