ViewVC Help
View File | Revision Log | Show Annotations | Download File
/cvs/libecb/ecb.h
Revision: 1.15
Committed: Thu May 26 18:31:02 2011 UTC (13 years ago) by sf-exg
Content type: text/plain
Branch: MAIN
Changes since 1.14: +1 -1 lines
Log Message:
Simplify.

File Contents

# 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 1.12 /* 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 root 1.14 #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 root 1.12 #endif
48 root 1.1
49 root 1.4 #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 root 1.8 #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 root 1.4 #define ECB_HEADER_INLINE static ECB_INLINE
65 root 1.3
66 root 1.1 #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 root 1.2 /* no emulation for ecb_decltype */
79 root 1.1 #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 root 1.4 #define ecb_hot ecb_attribute ((hot)) /* 4.3 */
91     #define ecb_cold ecb_attribute ((cold)) /* 4.3 */
92 root 1.1
93 root 1.3 /* 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 root 1.11 #define ecb_unlikely(expr) ecb_expect (!!(expr), 0)
97     #define ecb_likely(expr) ecb_expect (!!(expr), 1)
98 root 1.1
99 root 1.3 /* try to tell the compiler that some condition is definitely true */
100 root 1.1 #define ecb_assume(cond) do { if (!(cond)) unreachable (); } while (0)
101    
102 root 1.3 /* count trailing zero bits and count # of one bits */
103 root 1.14 ECB_HEADER_INLINE int ecb_ctz32 (uint32_t x) ecb_const;
104     ECB_HEADER_INLINE int ecb_popcount32 (uint32_t x) ecb_const;
105 root 1.1 #if ECB_GCC_VERSION(3,4)
106 root 1.6 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 root 1.1 #else
109 root 1.3 ECB_HEADER_INLINE
110 root 1.14 ecb_ctz32 (uint32_t x)
111 root 1.1 {
112     int r = 0;
113    
114 root 1.4 x &= -x; /* this isolates the lowest bit */
115 root 1.1
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 root 1.3 ECB_HEADER_INLINE
126 root 1.14 ecb_popcount32 (uint32_t x)
127 root 1.1 {
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 root 1.14 ECB_HEADER_INLINE uint32_t ecb_bswap32 (uint32_t x) ecb_const;
138 root 1.13 #if ECB_GCC_VERSION(4,3)
139 root 1.14 ECB_HEADER_INLINE uint32_t ecb_bswap32 (uint32_t x) { return __builtin_bswap32 (x); }
140 root 1.13 #else
141 root 1.14 ECB_HEADER_INLINE uint32_t
142 root 1.13 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 sf-exg 1.15 ECB_HEADER_INLINE void ecb_unreachable (void) ecb_noreturn;
152 root 1.13 #if ECB_GCC_VERSION(4,5)
153 root 1.14 ECB_HEADER_INLINE void ecb_unreachable (void) { __builtin_unreachable (); }
154 root 1.13 #else
155     /* this seems to work fine, but gcc always emits a warning for it :/ */
156 root 1.14 ECB_HEADER_INLINE void ecb_unreachable (void) { }
157 root 1.13 #endif
158    
159 root 1.14 ECB_HEADER_INLINE unsigned char ecb_byteorder_helper () ecb_const;
160    
161 root 1.3 ECB_HEADER_INLINE unsigned char
162 root 1.14 ecb_byteorder_helper ()
163 root 1.3 {
164     const uint32_t u = 0x11223344;
165     return *(unsigned char *)&u;
166     }
167    
168 root 1.14 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 root 1.3
173 root 1.5 #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 root 1.8 static inline int ecb_array_length (const T (&arr)[N])
177 root 1.5 {
178     return N;
179     }
180     #else
181     #define ecb_array_length(name) (sizeof (name) / sizeof (name [0]))
182     #endif
183    
184 root 1.14 ECB_INLINE uint32_t ecb_rotr32 (uint32_t x, unsigned int count) ecb_const;
185 root 1.6 ECB_INLINE uint32_t
186 root 1.9 ecb_rotr32 (uint32_t x, unsigned int count)
187 root 1.6 {
188 root 1.9 return (x << (32 - count)) | (x >> count);
189 root 1.6 }
190    
191 root 1.14 ECB_INLINE uint32_t ecb_rotl32 (uint32_t x, unsigned int count) ecb_const;
192 root 1.6 ECB_INLINE uint32_t
193 root 1.9 ecb_rotl32 (uint32_t x, unsigned int count)
194 root 1.6 {
195 root 1.9 return (x >> (32 - count)) | (x << count);
196 root 1.6 }
197    
198 root 1.1 #endif
199