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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 1.11 by root, Thu May 26 18:00:42 2011 UTC

1/* 1/*
2 * libecb 2 * libecb
3 * 3 *
4 * Copyright (c) 2011 Marc Alexander Lehmann 4 * Copyright (©) 2009-2011 Marc Alexander Lehmann
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
32#define ECB_GCC_VERSION(major,minor) (__GNUC__ > (major) || (__GNUC__ == (major) && __GNUC_MINOR__ >= (minor))) 35#define ECB_GCC_VERSION(major,minor) (__GNUC__ > (major) || (__GNUC__ == (major) && __GNUC_MINOR__ >= (minor)))
36
37#ifndef __cplusplus
38# if __STDC_VERSION__ >= 199901L
39# define ECB_INLINE inline
40typedef _Bool ecb_bool;
41# else
42# define ECB_INLINE inline /* yeah! */
43typedef int ecb_bool;
44# endif
45#endif
46
47#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#define ECB_HEADER_INLINE static ECB_INLINE
33 53
34#if ECB_GCC_VERSION(3,1) 54#if ECB_GCC_VERSION(3,1)
35# define ecb_attribute(attrlist) __attribute__(attrlist) 55# define ecb_attribute(attrlist) __attribute__(attrlist)
36# define ecb_is_constant(c) __builtin_constant_p (c) 56# define ecb_is_constant(c) __builtin_constant_p (c)
37# define ecb_expect(expr,value) __builtin_expect ((expr),(value)) 57# define ecb_expect(expr,value) __builtin_expect ((expr),(value))
… …
41# define ecb_is_constant(c) 0 61# define ecb_is_constant(c) 0
42# define ecb_expect(expr,value) (expr) 62# define ecb_expect(expr,value) (expr)
43# define ecb_prefetch(addr,rw,locality) 63# define ecb_prefetch(addr,rw,locality)
44#endif 64#endif
45 65
66/* no emulation for ecb_decltype */
46#if ECB_GCC_VERSION(4,5) 67#if ECB_GCC_VERSION(4,5)
47# define ecb_decltype(x) __decltype(x) 68# define ecb_decltype(x) __decltype(x)
48#elif ECB_GCC_VERSION(3,0) 69#elif ECB_GCC_VERSION(3,0)
49# define ecb_decltype(x) typeof(x) 70# define ecb_decltype(x) typeof(x)
50#endif 71#endif
… …
52#define ecb_noinline ecb_attribute ((noinline)) 73#define ecb_noinline ecb_attribute ((noinline))
53#define ecb_noreturn ecb_attribute ((noreturn)) 74#define ecb_noreturn ecb_attribute ((noreturn))
54#define ecb_unused ecb_attribute ((unused)) 75#define ecb_unused ecb_attribute ((unused))
55#define ecb_const ecb_attribute ((const)) 76#define ecb_const ecb_attribute ((const))
56#define ecb_pure ecb_attribute ((pure)) 77#define ecb_pure ecb_attribute ((pure))
57#define ecb_hot ecb_attribute ((hot)) // 4.3 78#define ecb_hot ecb_attribute ((hot)) /* 4.3 */
58#define ecb_cold ecb_attribute ((cold)) // 4.3 79#define ecb_cold ecb_attribute ((cold)) /* 4.3 */
59 80
60#if ECB_GCC_VERSION(4,5) 81#if ECB_GCC_VERSION(4,5)
61# define ecb_unreachable() __builtin_unreachable () 82# define ecb_unreachable() __builtin_unreachable ()
62#else 83#else
63 // this seems to work fine, but gcc always emits a warning for it :/ 84/* this seems to work fine, but gcc always emits a warning for it :/ */
64 static inline void ecb_unreachable () ecb_attribute ((noreturn)); 85ECB_HEADER_INLINE void ecb_unreachable () ecb_attribute ((noreturn));
65 static inline void ecb_unreachable () { } 86ECB_HEADER_INLINE void ecb_unreachable () { }
66#endif 87#endif
67 88
68// put into ifs if you are very sure that the expression 89/* put into ifs if you are very sure that the expression */
69// is mostly true or mosty false. note that these return 90/* is mostly true or mosty false. note that these return */
70// booleans, not the expression. 91/* booleans, not the expression. */
71#define ecb_expect_false(expr) ecb_expect ((expr) ? 1 : 0, 0) 92#define ecb_unlikely(expr) ecb_expect (!!(expr), 0)
72#define ecb_expect_true(expr) ecb_expect ((expr) ? 1 : 0, 1) 93#define ecb_likely(expr) ecb_expect (!!(expr), 1)
73 94
74// try to tell the compiler that some condition is definitely true 95/* try to tell the compiler that some condition is definitely true */
75#define ecb_assume(cond) do { if (!(cond)) unreachable (); } while (0) 96#define ecb_assume(cond) do { if (!(cond)) unreachable (); } while (0)
76 97
77// count trailing zero bits and count # of one bits 98/* count trailing zero bits and count # of one bits */
78#if ECB_GCC_VERSION(3,4) 99#if ECB_GCC_VERSION(3,4)
79static inline int ecb_ctz (unsigned int x) { return __builtin_ctz (x); } 100ECB_HEADER_INLINE int ecb_ctz32 (uint32_t x) { return __builtin_ctz (x); }
80static inline int ecb_popcount (unsigned int x) { return __builtin_popcount (x); } 101ECB_HEADER_INLINE int ecb_popcount32 (uint32_t x) { return __builtin_popcount (x); }
81#else 102#else
82static int ecb_ctz (unsigned int x) ecb_const 103ECB_HEADER_INLINE
104ecb_ctz32 (uint32_t x) ecb_const
83{ 105{
84 int r = 0; 106 int r = 0;
85 107
86 x &= -x; // this isolates the lowest bit 108 x &= -x; /* this isolates the lowest bit */
87 109
88 if (x & 0xaaaaaaaa) r += 1; 110 if (x & 0xaaaaaaaa) r += 1;
89 if (x & 0xcccccccc) r += 2; 111 if (x & 0xcccccccc) r += 2;
90 if (x & 0xf0f0f0f0) r += 4; 112 if (x & 0xf0f0f0f0) r += 4;
91 if (x & 0xff00ff00) r += 8; 113 if (x & 0xff00ff00) r += 8;
92 if (x & 0xffff0000) r += 16; 114 if (x & 0xffff0000) r += 16;
93 115
94 return r; 116 return r;
95} 117}
96 118
97static int ecb_popcount (unsigned int x) ecb_const 119ECB_HEADER_INLINE
120ecb_popcount32 (uint32_t x) ecb_const
98{ 121{
99 x -= (x >> 1) & 0x55555555; 122 x -= (x >> 1) & 0x55555555;
100 x = ((x >> 2) & 0x33333333) + (x & 0x33333333); 123 x = ((x >> 2) & 0x33333333) + (x & 0x33333333);
101 x = ((x >> 4) + x) & 0x0f0f0f0f; 124 x = ((x >> 4) + x) & 0x0f0f0f0f;
102 x *= 0x01010101; 125 x *= 0x01010101;
103 126
104 return x >> 24; 127 return x >> 24;
105} 128}
106#endif 129#endif
107 130
131ECB_HEADER_INLINE unsigned char
132ecb_byteorder_helper () ecb_const
133{
134 const uint32_t u = 0x11223344;
135 return *(unsigned char *)&u;
136}
137
138ECB_HEADER_INLINE ecb_bool ecb_big_endian () ecb_const { return ecb_byteorder_helper () == 0x11; };
139ECB_HEADER_INLINE ecb_bool ecb_little_endian () ecb_const { return ecb_byteorder_helper () == 0x44; };
140
141#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)
143template<typename T, int N>
144static inline int ecb_array_length (const T (&arr)[N])
145{
146 return N;
147}
148#else
149#define ecb_array_length(name) (sizeof (name) / sizeof (name [0]))
108#endif 150#endif
109 151
152ECB_INLINE uint32_t
153ecb_rotr32 (uint32_t x, unsigned int count)
154{
155 return (x << (32 - count)) | (x >> count);
156}
157
158ECB_INLINE uint32_t
159ecb_rotl32 (uint32_t x, unsigned int count)
160{
161 return (x >> (32 - count)) | (x << count);
162}
163
164#if ECB_GCC_VERSION(4,3)
165# define ecb_bswap32(x) __builtin_bswap32 (x)
166#else
167ECB_GCC_VERSION uint32_t
168ecb_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#endif
178

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