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Revision: 1.14
Committed: Thu May 26 18:26:59 2011 UTC (13 years, 1 month ago) by root
Content type: text/plain
Branch: MAIN
Changes since 1.13: +25 -14 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 /* many compilers define _GNUC_ to some versions but then only implement
36 * what their idiot authors think are the "more important" extensions,
37 * causing enourmous grief for some better fake benchmark numbers or so.
38 * we try to detect these and simply assume they are not gcc - if they have
39 * an issue with that they should have done it right in the first place.
40 */
41 #ifndef ECB_GCC_VERSION
42 # if defined(__INTEL_COMPILER) || defined(__SUNPRO_C) || defined(__llvm__)
43 # define ECB_GCC_VERSION(major,minor) 0
44 # else
45 # define ECB_GCC_VERSION(major,minor) (__GNUC__ > (major) || (__GNUC__ == (major) && __GNUC_MINOR__ >= (minor)))
46 # endif
47 #endif
48
49 #ifndef __cplusplus
50 # if __STDC_VERSION__ >= 199901L
51 # define ECB_INLINE inline
52 typedef _Bool ecb_bool;
53 # else
54 # define ECB_INLINE inline /* yeah! */
55 typedef int ecb_bool;
56 # endif
57 #endif
58
59 #define ECB_CONCAT_(a, b) a ## b
60 #define ECB_CONCAT(a, b) ECB_CONCAT_(a, b)
61 #define ECB_STRINGIFY_(a) # a
62 #define ECB_STRINGIFY(a) ECB_STRINGIFY_(a)
63
64 #define ECB_HEADER_INLINE static ECB_INLINE
65
66 #if ECB_GCC_VERSION(3,1)
67 # define ecb_attribute(attrlist) __attribute__(attrlist)
68 # define ecb_is_constant(c) __builtin_constant_p (c)
69 # define ecb_expect(expr,value) __builtin_expect ((expr),(value))
70 # define ecb_prefetch(addr,rw,locality) __builtin_prefetch (addr, rw, locality)
71 #else
72 # define ecb_attribute(attrlist)
73 # define ecb_is_constant(c) 0
74 # define ecb_expect(expr,value) (expr)
75 # define ecb_prefetch(addr,rw,locality)
76 #endif
77
78 /* no emulation for ecb_decltype */
79 #if ECB_GCC_VERSION(4,5)
80 # define ecb_decltype(x) __decltype(x)
81 #elif ECB_GCC_VERSION(3,0)
82 # define ecb_decltype(x) typeof(x)
83 #endif
84
85 #define ecb_noinline ecb_attribute ((noinline))
86 #define ecb_noreturn ecb_attribute ((noreturn))
87 #define ecb_unused ecb_attribute ((unused))
88 #define ecb_const ecb_attribute ((const))
89 #define ecb_pure ecb_attribute ((pure))
90 #define ecb_hot ecb_attribute ((hot)) /* 4.3 */
91 #define ecb_cold ecb_attribute ((cold)) /* 4.3 */
92
93 /* put into ifs if you are very sure that the expression */
94 /* is mostly true or mosty false. note that these return */
95 /* booleans, not the expression. */
96 #define ecb_unlikely(expr) ecb_expect (!!(expr), 0)
97 #define ecb_likely(expr) ecb_expect (!!(expr), 1)
98
99 /* try to tell the compiler that some condition is definitely true */
100 #define ecb_assume(cond) do { if (!(cond)) unreachable (); } while (0)
101
102 /* count trailing zero bits and count # of one bits */
103 ECB_HEADER_INLINE int ecb_ctz32 (uint32_t x) ecb_const;
104 ECB_HEADER_INLINE int ecb_popcount32 (uint32_t x) ecb_const;
105 #if ECB_GCC_VERSION(3,4)
106 ECB_HEADER_INLINE int ecb_ctz32 (uint32_t x) { return __builtin_ctz (x); }
107 ECB_HEADER_INLINE int ecb_popcount32 (uint32_t x) { return __builtin_popcount (x); }
108 #else
109 ECB_HEADER_INLINE
110 ecb_ctz32 (uint32_t x)
111 {
112 int r = 0;
113
114 x &= -x; /* this isolates the lowest bit */
115
116 if (x & 0xaaaaaaaa) r += 1;
117 if (x & 0xcccccccc) r += 2;
118 if (x & 0xf0f0f0f0) r += 4;
119 if (x & 0xff00ff00) r += 8;
120 if (x & 0xffff0000) r += 16;
121
122 return r;
123 }
124
125 ECB_HEADER_INLINE
126 ecb_popcount32 (uint32_t x)
127 {
128 x -= (x >> 1) & 0x55555555;
129 x = ((x >> 2) & 0x33333333) + (x & 0x33333333);
130 x = ((x >> 4) + x) & 0x0f0f0f0f;
131 x *= 0x01010101;
132
133 return x >> 24;
134 }
135 #endif
136
137 ECB_HEADER_INLINE uint32_t ecb_bswap32 (uint32_t x) ecb_const;
138 #if ECB_GCC_VERSION(4,3)
139 ECB_HEADER_INLINE uint32_t ecb_bswap32 (uint32_t x) { return __builtin_bswap32 (x); }
140 #else
141 ECB_HEADER_INLINE uint32_t
142 ecb_bswap32 (uint32_t x)
143 {
144 return (x >> 24)
145 | ((x >> 8) & 0x0000ff00)
146 | ((x << 8) & 0x00ff0000)
147 | (x << 24);
148 }
149 #endif
150
151 ECB_HEADER_INLINE void ecb_unreachable (void) ecb_attribute ((noreturn));
152 #if ECB_GCC_VERSION(4,5)
153 ECB_HEADER_INLINE void ecb_unreachable (void) { __builtin_unreachable (); }
154 #else
155 /* this seems to work fine, but gcc always emits a warning for it :/ */
156 ECB_HEADER_INLINE void ecb_unreachable (void) { }
157 #endif
158
159 ECB_HEADER_INLINE unsigned char ecb_byteorder_helper () ecb_const;
160
161 ECB_HEADER_INLINE unsigned char
162 ecb_byteorder_helper ()
163 {
164 const uint32_t u = 0x11223344;
165 return *(unsigned char *)&u;
166 }
167
168 ECB_HEADER_INLINE ecb_bool ecb_big_endian () ecb_const;
169 ECB_HEADER_INLINE ecb_bool ecb_big_endian () { return ecb_byteorder_helper () == 0x11; };
170 ECB_HEADER_INLINE ecb_bool ecb_little_endian () ecb_const;
171 ECB_HEADER_INLINE ecb_bool ecb_little_endian () { return ecb_byteorder_helper () == 0x44; };
172
173 #if ecb_cplusplus_does_not_suck
174 // does not work for local types (http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2657.htm)
175 template<typename T, int N>
176 static inline int ecb_array_length (const T (&arr)[N])
177 {
178 return N;
179 }
180 #else
181 #define ecb_array_length(name) (sizeof (name) / sizeof (name [0]))
182 #endif
183
184 ECB_INLINE uint32_t ecb_rotr32 (uint32_t x, unsigned int count) ecb_const;
185 ECB_INLINE uint32_t
186 ecb_rotr32 (uint32_t x, unsigned int count)
187 {
188 return (x << (32 - count)) | (x >> count);
189 }
190
191 ECB_INLINE uint32_t ecb_rotl32 (uint32_t x, unsigned int count) ecb_const;
192 ECB_INLINE uint32_t
193 ecb_rotl32 (uint32_t x, unsigned int count)
194 {
195 return (x >> (32 - count)) | (x << count);
196 }
197
198 #endif
199