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Revision: 1.10
Committed: Thu May 26 17:57:32 2011 UTC (13 years ago) by root
Content type: text/plain
Branch: MAIN
Changes since 1.9: +1 -1 lines
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# User Rev Content
1 root 1.1 /*
2     * libecb
3     *
4 root 1.2 * Copyright (©) 2009-2011 Marc Alexander Lehmann
5 root 1.7 * Copyright (©) 2011 Emanuele Giaquinta
6 root 1.1 * 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 root 1.6 #include <inttypes.h>
34    
35 root 1.1 #define ECB_GCC_VERSION(major,minor) (__GNUC__ > (major) || (__GNUC__ == (major) && __GNUC_MINOR__ >= (minor)))
36    
37 root 1.4 #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 root 1.8 #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 root 1.4 #define ECB_HEADER_INLINE static ECB_INLINE
53 root 1.3
54 root 1.1 #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 root 1.2 /* no emulation for ecb_decltype */
67 root 1.1 #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 root 1.4 #define ecb_hot ecb_attribute ((hot)) /* 4.3 */
79     #define ecb_cold ecb_attribute ((cold)) /* 4.3 */
80 root 1.1
81     #if ECB_GCC_VERSION(4,5)
82     # define ecb_unreachable() __builtin_unreachable ()
83     #else
84 root 1.4 /* 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 root 1.1 #endif
88    
89 root 1.3 /* 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 root 1.6 #define ecb_unlikely(expr) ecb_expect ((expr) ? 1 : 0, 0)
93     #define ecb_likely(expr) ecb_expect ((expr) ? 1 : 0, 1)
94 root 1.1
95 root 1.3 /* try to tell the compiler that some condition is definitely true */
96 root 1.1 #define ecb_assume(cond) do { if (!(cond)) unreachable (); } while (0)
97    
98 root 1.3 /* count trailing zero bits and count # of one bits */
99 root 1.1 #if ECB_GCC_VERSION(3,4)
100 root 1.6 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 root 1.1 #else
103 root 1.3 ECB_HEADER_INLINE
104 root 1.6 ecb_ctz32 (uint32_t x) ecb_const
105 root 1.1 {
106     int r = 0;
107    
108 root 1.4 x &= -x; /* this isolates the lowest bit */
109 root 1.1
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 root 1.3 ECB_HEADER_INLINE
120 root 1.6 ecb_popcount32 (uint32_t x) ecb_const
121 root 1.1 {
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 root 1.3 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 root 1.4 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 root 1.3
141 root 1.5 #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 root 1.8 static inline int ecb_array_length (const T (&arr)[N])
145 root 1.5 {
146     return N;
147     }
148     #else
149     #define ecb_array_length(name) (sizeof (name) / sizeof (name [0]))
150     #endif
151    
152 root 1.6 ECB_INLINE uint32_t
153 root 1.9 ecb_rotr32 (uint32_t x, unsigned int count)
154 root 1.6 {
155 root 1.9 return (x << (32 - count)) | (x >> count);
156 root 1.6 }
157    
158     ECB_INLINE uint32_t
159 root 1.9 ecb_rotl32 (uint32_t x, unsigned int count)
160 root 1.6 {
161 root 1.9 return (x >> (32 - count)) | (x << count);
162 root 1.6 }
163    
164 root 1.10 #if ECB_GCC_VERSION(4,3)
165 root 1.9 # 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 root 1.1 #endif
178