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Comparing libecb/ecb.h (file contents):
Revision 1.1 by root, Thu May 26 16:41:12 2011 UTC vs.
Revision 1.39 by root, Sat Jun 11 14:18:49 2011 UTC

1/* 1/*
2 * libecb 2 * libecb - http://software.schmorp.de/pkg/libecb
3 * 3 *
4 * Copyright (c) 2011 Marc Alexander Lehmann 4 * Copyright (©) 2009-2011 Marc Alexander Lehmann <libecb@schmorp.de>
5 * Copyright (©) 2011 Emanuele Giaquinta
5 * All rights reserved. 6 * All rights reserved.
6 * 7 *
7 * Redistribution and use in source and binary forms, with or without modifica- 8 * Redistribution and use in source and binary forms, with or without modifica-
8 * tion, are permitted provided that the following conditions are met: 9 * tion, are permitted provided that the following conditions are met:
9 * 10 *
… …
27 */ 28 */
28 29
29#ifndef ECB_H 30#ifndef ECB_H
30#define ECB_H 31#define ECB_H
31 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
32#define ECB_GCC_VERSION(major,minor) (__GNUC__ > (major) || (__GNUC__ == (major) && __GNUC_MINOR__ >= (minor))) 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
70typedef 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
33 78
34#if ECB_GCC_VERSION(3,1) 79#if ECB_GCC_VERSION(3,1)
35# define ecb_attribute(attrlist) __attribute__(attrlist) 80 #define ecb_attribute(attrlist) __attribute__(attrlist)
36# define ecb_is_constant(c) __builtin_constant_p (c) 81 #define ecb_is_constant(expr) __builtin_constant_p (expr)
37# define ecb_expect(expr,value) __builtin_expect ((expr),(value)) 82 #define ecb_expect(expr,value) __builtin_expect ((expr),(value))
38# define ecb_prefetch(addr,rw,locality) __builtin_prefetch (addr, rw, locality) 83 #define ecb_prefetch(addr,rw,locality) __builtin_prefetch (addr, rw, locality)
39#else 84#else
40# define ecb_attribute(attrlist) 85 #define ecb_attribute(attrlist)
41# define ecb_is_constant(c) 0 86 #define ecb_is_constant(expr) 0
42# define ecb_expect(expr,value) (expr) 87 #define ecb_expect(expr,value) (expr)
43# define ecb_prefetch(addr,rw,locality) 88 #define ecb_prefetch(addr,rw,locality)
44#endif 89#endif
45 90
91/* no emulation for ecb_decltype */
46#if ECB_GCC_VERSION(4,5) 92#if ECB_GCC_VERSION(4,5)
47# define ecb_decltype(x) __decltype(x) 93 #define ecb_decltype(x) __decltype(x)
48#elif ECB_GCC_VERSION(3,0) 94#elif ECB_GCC_VERSION(3,0)
49# define ecb_decltype(x) typeof(x) 95 #define ecb_decltype(x) __typeof(x)
50#endif 96#endif
51 97
52#define ecb_noinline ecb_attribute ((noinline)) 98#define ecb_noinline ecb_attribute ((__noinline__))
53#define ecb_noreturn ecb_attribute ((noreturn)) 99#define ecb_noreturn ecb_attribute ((__noreturn__))
54#define ecb_unused ecb_attribute ((unused)) 100#define ecb_unused ecb_attribute ((__unused__))
55#define ecb_const ecb_attribute ((const)) 101#define ecb_const ecb_attribute ((__const__))
56#define ecb_pure ecb_attribute ((pure)) 102#define ecb_pure ecb_attribute ((__pure__))
103
104#if ECB_GCC_VERSION(4,3)
105 #define ecb_artificial ecb_attribute ((__artificial__))
57#define ecb_hot ecb_attribute ((hot)) // 4.3 106 #define ecb_hot ecb_attribute ((__hot__))
58#define ecb_cold ecb_attribute ((cold)) // 4.3 107 #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
59 184
60#if ECB_GCC_VERSION(4,5) 185#if ECB_GCC_VERSION(4,5)
61# define ecb_unreachable() __builtin_unreachable () 186 #define ecb_unreachable() __builtin_unreachable ()
62#else 187#else
63 // this seems to work fine, but gcc always emits a warning for it :/ 188 /* this seems to work fine, but gcc always emits a warning for it :/ */
64 static inline void ecb_unreachable () ecb_attribute ((noreturn)); 189 ecb_function_ void ecb_unreachable (void) ecb_noreturn;
65 static inline void ecb_unreachable () { } 190 ecb_function_ void ecb_unreachable (void) { }
66#endif 191#endif
67 192
68// put into ifs if you are very sure that the expression 193ecb_function_ unsigned char ecb_byteorder_helper (void) ecb_const;
69// is mostly true or mosty false. note that these return 194ecb_function_ unsigned char
70// booleans, not the expression. 195ecb_byteorder_helper (void)
71#define ecb_expect_false(expr) ecb_expect ((expr) ? 1 : 0, 0)
72#define ecb_expect_true(expr) ecb_expect ((expr) ? 1 : 0, 1)
73
74// try to tell the compiler that some condition is definitely true
75#define ecb_assume(cond) do { if (!(cond)) unreachable (); } while (0)
76
77// count trailing zero bits and count # of one bits
78#if ECB_GCC_VERSION(3,4)
79static inline int ecb_ctz (unsigned int x) { return __builtin_ctz (x); }
80static inline int ecb_popcount (unsigned int x) { return __builtin_popcount (x); }
81#else
82static int ecb_ctz (unsigned int x) ecb_const
83{ 196{
84 int r = 0; 197 const uint32_t u = 0x11223344;
85 198 return *(unsigned char *)&u;
86 x &= -x; // this isolates the lowest bit
87
88 if (x & 0xaaaaaaaa) r += 1;
89 if (x & 0xcccccccc) r += 2;
90 if (x & 0xf0f0f0f0) r += 4;
91 if (x & 0xff00ff00) r += 8;
92 if (x & 0xffff0000) r += 16;
93
94 return r;
95} 199}
96 200
97static int ecb_popcount (unsigned int x) ecb_const 201ecb_function_ ecb_bool ecb_big_endian (void) ecb_const;
202ecb_function_ ecb_bool ecb_big_endian (void) { return ecb_byteorder_helper () == 0x11; };
203ecb_function_ ecb_bool ecb_little_endian (void) ecb_const;
204ecb_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
223ECB_INLINE uint32_t ecb_rotr32 (uint32_t x, unsigned int count) ecb_const;
224ECB_INLINE uint32_t
225ecb_rotr32 (uint32_t x, unsigned int count)
98{ 226{
99 x -= (x >> 1) & 0x55555555; 227 return (x << (32 - count)) | (x >> count);
100 x = ((x >> 2) & 0x33333333) + (x & 0x33333333);
101 x = ((x >> 4) + x) & 0x0f0f0f0f;
102 x *= 0x01010101;
103
104 return x >> 24;
105} 228}
106#endif
107 229
108#endif 230ECB_INLINE uint32_t ecb_rotl32 (uint32_t x, unsigned int count) ecb_const;
231ECB_INLINE uint32_t
232ecb_rotl32 (uint32_t x, unsigned int count)
233{
234 return (x >> (32 - count)) | (x << count);
235}
109 236
237#endif
238

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