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/cvs/libecb/ecb.h
Revision: 1.38
Committed: Sat Jun 11 14:02:40 2011 UTC (13 years ago) by root
Content type: text/plain
Branch: MAIN
Changes since 1.37: +17 -10 lines
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# Content
1 /*
2 * libecb - http://software.schmorp.de/pkg/libecb
3 *
4 * Copyright (©) 2009-2011 Marc Alexander Lehmann <libecb@schmorp.de>
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 in return for some better fake benchmark numbers.
38 * or so.
39 * we try to detect these and simply assume they are not gcc - if they have
40 * an issue with that they should have done it right in the first place.
41 */
42 #ifndef ECB_GCC_VERSION
43 #if defined(__INTEL_COMPILER) || defined(__SUNPRO_C) || defined(__llvm__)
44 #define ECB_GCC_VERSION(major,minor) 0
45 #else
46 #define ECB_GCC_VERSION(major,minor) (__GNUC__ > (major) || (__GNUC__ == (major) && __GNUC_MINOR__ >= (minor)))
47 #endif
48 #endif
49
50 #ifdef __cplusplus
51 #define ECB_INLINE static inline
52 #elif ECB_GCC_VERSION(2,5)
53 #define ECB_INLINE static __inline__
54 #elif __STDC_VERSION__ >= 199901L
55 #define ECB_INLINE static inline
56 #else
57 #define ECB_INLINE static
58 #endif
59
60 #if ECB_GCC_VERSION(3,3)
61 #define ecb_restrict __restrict__
62 #elif __STDC_VERSION__ >= 199901L
63 #define ecb_restrict restrict
64 #else
65 #define ecb_restrict
66 #endif
67
68 typedef int ecb_bool;
69
70 #define ECB_CONCAT_(a, b) a ## b
71 #define ECB_CONCAT(a, b) ECB_CONCAT_(a, b)
72 #define ECB_STRINGIFY_(a) # a
73 #define ECB_STRINGIFY(a) ECB_STRINGIFY_(a)
74
75 #define ECB_HEADER_INLINE ECB_INLINE
76
77 #if ECB_GCC_VERSION(3,1)
78 #define ecb_attribute(attrlist) __attribute__(attrlist)
79 #define ecb_is_constant(expr) __builtin_constant_p (expr)
80 #define ecb_expect(expr,value) __builtin_expect ((expr),(value))
81 #define ecb_prefetch(addr,rw,locality) __builtin_prefetch (addr, rw, locality)
82 #else
83 #define ecb_attribute(attrlist)
84 #define ecb_is_constant(expr) 0
85 #define ecb_expect(expr,value) (expr)
86 #define ecb_prefetch(addr,rw,locality)
87 #endif
88
89 /* no emulation for ecb_decltype */
90 #if ECB_GCC_VERSION(4,5)
91 #define ecb_decltype(x) __decltype(x)
92 #elif ECB_GCC_VERSION(3,0)
93 #define ecb_decltype(x) typeof(x)
94 #endif
95
96 #define ecb_noinline ecb_attribute ((__noinline__))
97 #define ecb_noreturn ecb_attribute ((__noreturn__))
98 #define ecb_unused ecb_attribute ((__unused__))
99 #define ecb_const ecb_attribute ((__const__))
100 #define ecb_pure ecb_attribute ((__pure__))
101
102 #if ECB_GCC_VERSION(4,3)
103 #define ecb_artificial ecb_attribute ((__artificial__)) /* 4.3 */
104 #define ecb_hot ecb_attribute ((__hot__)) /* 4.3 */
105 #define ecb_cold ecb_attribute ((__cold__)) /* 4.3 */
106 #else
107 #define ecb_artificial
108 #define ecb_hot
109 #define ecb_cold
110 #endif
111
112 /* put into if's if you are very sure that the expression */
113 /* is mostly true or mostly false. note that these return */
114 /* booleans, not the expression. */
115 #define ecb_expect_false(expr) ecb_expect (!!(expr), 0)
116 #define ecb_expect_true(expr) ecb_expect (!!(expr), 1)
117 /* for compatibility to the rest of the world */
118 #define ecb_likely(expr) ecb_expect_true (expr)
119 #define ecb_unlikely(expr) ecb_expect_false (expr)
120
121 /* try to tell the compiler that some condition is definitely true */
122 #define ecb_assume(cond) do { if (!(cond)) ecb_unreachable (); } while (0)
123
124 /* count trailing zero bits and count # of one bits */
125 #if ECB_GCC_VERSION(3,4)
126 #define ecb_ctz32(x) __builtin_ctz (x)
127 #define ecb_popcount32(x) __builtin_popcount (x)
128 #else
129 ECB_HEADER_INLINE int ecb_ctz32 (uint32_t x) ecb_const;
130 ECB_HEADER_INLINE int
131 ecb_ctz32 (uint32_t x)
132 {
133 int r = 0;
134
135 x &= -x; /* this isolates the lowest bit */
136
137 if (x & 0xaaaaaaaa) r += 1;
138 if (x & 0xcccccccc) r += 2;
139 if (x & 0xf0f0f0f0) r += 4;
140 if (x & 0xff00ff00) r += 8;
141 if (x & 0xffff0000) r += 16;
142
143 return r;
144 }
145
146 ECB_HEADER_INLINE int ecb_popcount32 (uint32_t x) ecb_const;
147 ECB_HEADER_INLINE int
148 ecb_popcount32 (uint32_t x)
149 {
150 x -= (x >> 1) & 0x55555555;
151 x = ((x >> 2) & 0x33333333) + (x & 0x33333333);
152 x = ((x >> 4) + x) & 0x0f0f0f0f;
153 x *= 0x01010101;
154
155 return x >> 24;
156 }
157 #endif
158
159 #if ECB_GCC_VERSION(4,3)
160 #define ecb_bswap32(x) __builtin_bswap32 (x)
161 #define ecb_bswap16(x) (__builtin_bswap32(x) >> 16)
162 #else
163 ECB_HEADER_INLINE uint32_t ecb_bswap32 (uint32_t x) ecb_const;
164 ECB_HEADER_INLINE uint32_t
165 ecb_bswap32 (uint32_t x)
166 {
167 return (x >> 24)
168 | ((x >> 8) & 0x0000ff00)
169 | ((x << 8) & 0x00ff0000)
170 | (x << 24);
171 }
172
173 ECB_HEADER_INLINE uint32_t ecb_bswap16 (uint32_t x) ecb_const;
174 ECB_HEADER_INLINE uint32_t
175 ecb_bswap16 (uint32_t x)
176 {
177 return ((x >> 8) & 0xff)
178 | ((x << 8) & 0x00ff0000)
179 | (x << 24);
180 }
181 #endif
182
183 #if ECB_GCC_VERSION(4,5)
184 #define ecb_unreachable() __builtin_unreachable ()
185 #else
186 /* this seems to work fine, but gcc always emits a warning for it :/ */
187 ECB_HEADER_INLINE void ecb_unreachable (void) ecb_noreturn;
188 ECB_HEADER_INLINE void ecb_unreachable (void) { }
189 #endif
190
191 ECB_HEADER_INLINE unsigned char ecb_byteorder_helper (void) ecb_const;
192 ECB_HEADER_INLINE unsigned char
193 ecb_byteorder_helper (void)
194 {
195 const uint32_t u = 0x11223344;
196 return *(unsigned char *)&u;
197 }
198
199 ECB_HEADER_INLINE ecb_bool ecb_big_endian (void) ecb_const;
200 ECB_HEADER_INLINE ecb_bool ecb_big_endian (void) { return ecb_byteorder_helper () == 0x11; };
201 ECB_HEADER_INLINE ecb_bool ecb_little_endian (void) ecb_const;
202 ECB_HEADER_INLINE ecb_bool ecb_little_endian (void) { return ecb_byteorder_helper () == 0x44; };
203
204 #if ECB_GCC_VERSION(3,0)
205 #define ecb_mod(m,n) ((m) % (n) + ((m) % (n) < 0 ? (n) : 0))
206 #else
207 #define ecb_mod(m,n) ((m) < 0 ? ((n) - 1 - ((-1 - (m)) % (n))) : ((m) % (n)))
208 #endif
209
210 #if ecb_cplusplus_does_not_suck
211 // does not work for local types (http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2657.htm)
212 template<typename T, int N>
213 static inline int ecb_array_length (const T (&arr)[N])
214 {
215 return N;
216 }
217 #else
218 #define ecb_array_length(name) (sizeof (name) / sizeof (name [0]))
219 #endif
220
221 ECB_INLINE uint32_t ecb_rotr32 (uint32_t x, unsigned int count) ecb_const;
222 ECB_INLINE uint32_t
223 ecb_rotr32 (uint32_t x, unsigned int count)
224 {
225 return (x << (32 - count)) | (x >> count);
226 }
227
228 ECB_INLINE uint32_t ecb_rotl32 (uint32_t x, unsigned int count) ecb_const;
229 ECB_INLINE uint32_t
230 ecb_rotl32 (uint32_t x, unsigned int count)
231 {
232 return (x >> (32 - count)) | (x << count);
233 }
234
235 #endif
236