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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 1.13 by root, Thu May 26 18:21:04 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
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 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#if defined(__INTEL_COMPILER) || defined(__SUNPRO_C) || defined(__llvm__)
42# define ECB_GCC_VERSION(major,minor) 0
43#else
32#define ECB_GCC_VERSION(major,minor) (__GNUC__ > (major) || (__GNUC__ == (major) && __GNUC_MINOR__ >= (minor))) 44# define ECB_GCC_VERSION(major,minor) (__GNUC__ > (major) || (__GNUC__ == (major) && __GNUC_MINOR__ >= (minor)))
45#endif
46
47#ifndef __cplusplus
48# if __STDC_VERSION__ >= 199901L
49# define ECB_INLINE inline
50typedef _Bool ecb_bool;
51# else
52# define ECB_INLINE inline /* yeah! */
53typedef int ecb_bool;
54# endif
55#endif
56
57#define ECB_CONCAT_(a, b) a ## b
58#define ECB_CONCAT(a, b) ECB_CONCAT_(a, b)
59#define ECB_STRINGIFY_(a) # a
60#define ECB_STRINGIFY(a) ECB_STRINGIFY_(a)
61
62#define ECB_HEADER_INLINE static ECB_INLINE
33 63
34#if ECB_GCC_VERSION(3,1) 64#if ECB_GCC_VERSION(3,1)
35# define ecb_attribute(attrlist) __attribute__(attrlist) 65# define ecb_attribute(attrlist) __attribute__(attrlist)
36# define ecb_is_constant(c) __builtin_constant_p (c) 66# define ecb_is_constant(c) __builtin_constant_p (c)
37# define ecb_expect(expr,value) __builtin_expect ((expr),(value)) 67# define ecb_expect(expr,value) __builtin_expect ((expr),(value))
… …
41# define ecb_is_constant(c) 0 71# define ecb_is_constant(c) 0
42# define ecb_expect(expr,value) (expr) 72# define ecb_expect(expr,value) (expr)
43# define ecb_prefetch(addr,rw,locality) 73# define ecb_prefetch(addr,rw,locality)
44#endif 74#endif
45 75
76/* no emulation for ecb_decltype */
46#if ECB_GCC_VERSION(4,5) 77#if ECB_GCC_VERSION(4,5)
47# define ecb_decltype(x) __decltype(x) 78# define ecb_decltype(x) __decltype(x)
48#elif ECB_GCC_VERSION(3,0) 79#elif ECB_GCC_VERSION(3,0)
49# define ecb_decltype(x) typeof(x) 80# define ecb_decltype(x) typeof(x)
50#endif 81#endif
… …
52#define ecb_noinline ecb_attribute ((noinline)) 83#define ecb_noinline ecb_attribute ((noinline))
53#define ecb_noreturn ecb_attribute ((noreturn)) 84#define ecb_noreturn ecb_attribute ((noreturn))
54#define ecb_unused ecb_attribute ((unused)) 85#define ecb_unused ecb_attribute ((unused))
55#define ecb_const ecb_attribute ((const)) 86#define ecb_const ecb_attribute ((const))
56#define ecb_pure ecb_attribute ((pure)) 87#define ecb_pure ecb_attribute ((pure))
57#define ecb_hot ecb_attribute ((hot)) // 4.3 88#define ecb_hot ecb_attribute ((hot)) /* 4.3 */
58#define ecb_cold ecb_attribute ((cold)) // 4.3 89#define ecb_cold ecb_attribute ((cold)) /* 4.3 */
59 90
60#if ECB_GCC_VERSION(4,5) 91/* put into ifs if you are very sure that the expression */
61# define ecb_unreachable() __builtin_unreachable () 92/* is mostly true or mosty false. note that these return */
62#else 93/* booleans, not the expression. */
63 // this seems to work fine, but gcc always emits a warning for it :/ 94#define ecb_unlikely(expr) ecb_expect (!!(expr), 0)
64 static inline void ecb_unreachable () ecb_attribute ((noreturn)); 95#define ecb_likely(expr) ecb_expect (!!(expr), 1)
65 static inline void ecb_unreachable () { }
66#endif
67 96
68// put into ifs if you are very sure that the expression
69// is mostly true or mosty false. note that these return
70// booleans, not the expression.
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 97/* try to tell the compiler that some condition is definitely true */
75#define ecb_assume(cond) do { if (!(cond)) unreachable (); } while (0) 98#define ecb_assume(cond) do { if (!(cond)) unreachable (); } while (0)
76 99
77// count trailing zero bits and count # of one bits 100/* count trailing zero bits and count # of one bits */
78#if ECB_GCC_VERSION(3,4) 101#if ECB_GCC_VERSION(3,4)
79static inline int ecb_ctz (unsigned int x) { return __builtin_ctz (x); } 102ECB_HEADER_INLINE int ecb_ctz32 (uint32_t x) { return __builtin_ctz (x); }
80static inline int ecb_popcount (unsigned int x) { return __builtin_popcount (x); } 103ECB_HEADER_INLINE int ecb_popcount32 (uint32_t x) { return __builtin_popcount (x); }
81#else 104#else
82static int ecb_ctz (unsigned int x) ecb_const 105ECB_HEADER_INLINE
106ecb_ctz32 (uint32_t x) ecb_const
83{ 107{
84 int r = 0; 108 int r = 0;
85 109
86 x &= -x; // this isolates the lowest bit 110 x &= -x; /* this isolates the lowest bit */
87 111
88 if (x & 0xaaaaaaaa) r += 1; 112 if (x & 0xaaaaaaaa) r += 1;
89 if (x & 0xcccccccc) r += 2; 113 if (x & 0xcccccccc) r += 2;
90 if (x & 0xf0f0f0f0) r += 4; 114 if (x & 0xf0f0f0f0) r += 4;
91 if (x & 0xff00ff00) r += 8; 115 if (x & 0xff00ff00) r += 8;
92 if (x & 0xffff0000) r += 16; 116 if (x & 0xffff0000) r += 16;
93 117
94 return r; 118 return r;
95} 119}
96 120
97static int ecb_popcount (unsigned int x) ecb_const 121ECB_HEADER_INLINE
122ecb_popcount32 (uint32_t x) ecb_const
98{ 123{
99 x -= (x >> 1) & 0x55555555; 124 x -= (x >> 1) & 0x55555555;
100 x = ((x >> 2) & 0x33333333) + (x & 0x33333333); 125 x = ((x >> 2) & 0x33333333) + (x & 0x33333333);
101 x = ((x >> 4) + x) & 0x0f0f0f0f; 126 x = ((x >> 4) + x) & 0x0f0f0f0f;
102 x *= 0x01010101; 127 x *= 0x01010101;
103 128
104 return x >> 24; 129 return x >> 24;
105} 130}
106#endif 131#endif
107 132
133#if ECB_GCC_VERSION(4,3)
134ECB_GCC_VERSION uint32_t ecb_bswap32 (uint32_t x) { return __builtin_bswap32 (x); }
135#else
136ECB_GCC_VERSION uint32_t
137ecb_bswap32 (uint32_t x)
138{
139 return (x >> 24)
140 | ((x >> 8) & 0x0000ff00)
141 | ((x << 8) & 0x00ff0000)
142 | (x << 24);
143}
108#endif 144#endif
109 145
146#if ECB_GCC_VERSION(4,5)
147# define ecb_unreachable() __builtin_unreachable ()
148#else
149/* this seems to work fine, but gcc always emits a warning for it :/ */
150ECB_HEADER_INLINE void ecb_unreachable () ecb_attribute ((noreturn));
151ECB_HEADER_INLINE void ecb_unreachable () { }
152#endif
153
154ECB_HEADER_INLINE unsigned char
155ecb_byteorder_helper () ecb_const
156{
157 const uint32_t u = 0x11223344;
158 return *(unsigned char *)&u;
159}
160
161ECB_HEADER_INLINE ecb_bool ecb_big_endian () ecb_const { return ecb_byteorder_helper () == 0x11; };
162ECB_HEADER_INLINE ecb_bool ecb_little_endian () ecb_const { return ecb_byteorder_helper () == 0x44; };
163
164#if ecb_cplusplus_does_not_suck
165// does not work for local types (http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2657.htm)
166template<typename T, int N>
167static inline int ecb_array_length (const T (&arr)[N])
168{
169 return N;
170}
171#else
172#define ecb_array_length(name) (sizeof (name) / sizeof (name [0]))
173#endif
174
175ECB_INLINE uint32_t
176ecb_rotr32 (uint32_t x, unsigned int count)
177{
178 return (x << (32 - count)) | (x >> count);
179}
180
181ECB_INLINE uint32_t
182ecb_rotl32 (uint32_t x, unsigned int count)
183{
184 return (x >> (32 - count)) | (x << count);
185}
186
187#endif
188

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