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/cvs/libecb/ecb.h
Revision: 1.39
Committed: Sat Jun 11 14:18:49 2011 UTC (13 years ago) by root
Content type: text/plain
Branch: MAIN
Changes since 1.38: +30 -28 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 #define ECB_C99 (__STDC_VERSION__ >= 199901L)
51
52 #if __cplusplus
53 #define ECB_INLINE static inline
54 #elif ECB_GCC_VERSION(2,5)
55 #define ECB_INLINE static __inline__
56 #elif ECB_C99
57 #define ECB_INLINE static inline
58 #else
59 #define ECB_INLINE static
60 #endif
61
62 #if ECB_GCC_VERSION(3,3)
63 #define ecb_restrict __restrict__
64 #elif ECB_C99
65 #define ecb_restrict restrict
66 #else
67 #define ecb_restrict
68 #endif
69
70 typedef int ecb_bool;
71
72 #define ECB_CONCAT_(a, b) a ## b
73 #define ECB_CONCAT(a, b) ECB_CONCAT_(a, b)
74 #define ECB_STRINGIFY_(a) # a
75 #define ECB_STRINGIFY(a) ECB_STRINGIFY_(a)
76
77 #define ecb_function_ ECB_INLINE
78
79 #if ECB_GCC_VERSION(3,1)
80 #define ecb_attribute(attrlist) __attribute__(attrlist)
81 #define ecb_is_constant(expr) __builtin_constant_p (expr)
82 #define ecb_expect(expr,value) __builtin_expect ((expr),(value))
83 #define ecb_prefetch(addr,rw,locality) __builtin_prefetch (addr, rw, locality)
84 #else
85 #define ecb_attribute(attrlist)
86 #define ecb_is_constant(expr) 0
87 #define ecb_expect(expr,value) (expr)
88 #define ecb_prefetch(addr,rw,locality)
89 #endif
90
91 /* no emulation for ecb_decltype */
92 #if ECB_GCC_VERSION(4,5)
93 #define ecb_decltype(x) __decltype(x)
94 #elif ECB_GCC_VERSION(3,0)
95 #define ecb_decltype(x) __typeof(x)
96 #endif
97
98 #define ecb_noinline ecb_attribute ((__noinline__))
99 #define ecb_noreturn ecb_attribute ((__noreturn__))
100 #define ecb_unused ecb_attribute ((__unused__))
101 #define ecb_const ecb_attribute ((__const__))
102 #define ecb_pure ecb_attribute ((__pure__))
103
104 #if ECB_GCC_VERSION(4,3)
105 #define ecb_artificial ecb_attribute ((__artificial__))
106 #define ecb_hot ecb_attribute ((__hot__))
107 #define ecb_cold ecb_attribute ((__cold__))
108 #else
109 #define ecb_artificial
110 #define ecb_hot
111 #define ecb_cold
112 #endif
113
114 /* put around conditional expressions if you are very sure that the */
115 /* expression is mostly true or mostly false. note that these return */
116 /* booleans, not the expression. */
117 #define ecb_expect_false(expr) ecb_expect (!!(expr), 0)
118 #define ecb_expect_true(expr) ecb_expect (!!(expr), 1)
119 /* for compatibility to the rest of the world */
120 #define ecb_likely(expr) ecb_expect_true (expr)
121 #define ecb_unlikely(expr) ecb_expect_false (expr)
122
123 /* try to tell the compiler that some condition is definitely true */
124 #define ecb_assume(cond) do { if (!(cond)) ecb_unreachable (); } while (0)
125
126 /* count trailing zero bits and count # of one bits */
127 #if ECB_GCC_VERSION(3,4)
128 #define ecb_ctz32(x) __builtin_ctz (x)
129 #define ecb_popcount32(x) __builtin_popcount (x)
130 #else
131 ecb_function_ int ecb_ctz32 (uint32_t x) ecb_const;
132 ecb_function_ int
133 ecb_ctz32 (uint32_t x)
134 {
135 int r = 0;
136
137 x &= -x; /* this isolates the lowest bit */
138
139 if (x & 0xaaaaaaaa) r += 1;
140 if (x & 0xcccccccc) r += 2;
141 if (x & 0xf0f0f0f0) r += 4;
142 if (x & 0xff00ff00) r += 8;
143 if (x & 0xffff0000) r += 16;
144
145 return r;
146 }
147
148 ecb_function_ int ecb_popcount32 (uint32_t x) ecb_const;
149 ecb_function_ int
150 ecb_popcount32 (uint32_t x)
151 {
152 x -= (x >> 1) & 0x55555555;
153 x = ((x >> 2) & 0x33333333) + (x & 0x33333333);
154 x = ((x >> 4) + x) & 0x0f0f0f0f;
155 x *= 0x01010101;
156
157 return x >> 24;
158 }
159 #endif
160
161 #if ECB_GCC_VERSION(4,3)
162 #define ecb_bswap32(x) __builtin_bswap32 (x)
163 #define ecb_bswap16(x) (__builtin_bswap32(x) >> 16)
164 #else
165 ecb_function_ uint32_t ecb_bswap32 (uint32_t x) ecb_const;
166 ecb_function_ uint32_t
167 ecb_bswap32 (uint32_t x)
168 {
169 return (x >> 24)
170 | ((x >> 8) & 0x0000ff00)
171 | ((x << 8) & 0x00ff0000)
172 | (x << 24);
173 }
174
175 ecb_function_ uint32_t ecb_bswap16 (uint32_t x) ecb_const;
176 ecb_function_ uint32_t
177 ecb_bswap16 (uint32_t x)
178 {
179 return ((x >> 8) & 0xff)
180 | ((x << 8) & 0x00ff0000)
181 | (x << 24);
182 }
183 #endif
184
185 #if ECB_GCC_VERSION(4,5)
186 #define ecb_unreachable() __builtin_unreachable ()
187 #else
188 /* this seems to work fine, but gcc always emits a warning for it :/ */
189 ecb_function_ void ecb_unreachable (void) ecb_noreturn;
190 ecb_function_ void ecb_unreachable (void) { }
191 #endif
192
193 ecb_function_ unsigned char ecb_byteorder_helper (void) ecb_const;
194 ecb_function_ unsigned char
195 ecb_byteorder_helper (void)
196 {
197 const uint32_t u = 0x11223344;
198 return *(unsigned char *)&u;
199 }
200
201 ecb_function_ ecb_bool ecb_big_endian (void) ecb_const;
202 ecb_function_ ecb_bool ecb_big_endian (void) { return ecb_byteorder_helper () == 0x11; };
203 ecb_function_ ecb_bool ecb_little_endian (void) ecb_const;
204 ecb_function_ ecb_bool ecb_little_endian (void) { return ecb_byteorder_helper () == 0x44; };
205
206 #if ECB_GCC_VERSION(3,0) || ECB_C99
207 #define ecb_mod(m,n) ((m) % (n) + ((m) % (n) < 0 ? (n) : 0))
208 #else
209 #define ecb_mod(m,n) ((m) < 0 ? ((n) - 1 - ((-1 - (m)) % (n))) : ((m) % (n)))
210 #endif
211
212 #if ecb_cplusplus_does_not_suck
213 // does not work for local types (http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2657.htm)
214 template<typename T, int N>
215 static inline int ecb_array_length (const T (&arr)[N])
216 {
217 return N;
218 }
219 #else
220 #define ecb_array_length(name) (sizeof (name) / sizeof (name [0]))
221 #endif
222
223 ECB_INLINE uint32_t ecb_rotr32 (uint32_t x, unsigned int count) ecb_const;
224 ECB_INLINE uint32_t
225 ecb_rotr32 (uint32_t x, unsigned int count)
226 {
227 return (x << (32 - count)) | (x >> count);
228 }
229
230 ECB_INLINE uint32_t ecb_rotl32 (uint32_t x, unsigned int count) ecb_const;
231 ECB_INLINE uint32_t
232 ecb_rotl32 (uint32_t x, unsigned int count)
233 {
234 return (x >> (32 - count)) | (x << count);
235 }
236
237 #endif
238