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Comparing libecb/ecb.h (file contents):
Revision 1.2 by root, Thu May 26 16:46:48 2011 UTC vs.
Revision 1.3 by root, Thu May 26 16:57:04 2011 UTC

… …
29#ifndef ECB_H 29#ifndef ECB_H
30#define ECB_H 30#define ECB_H
31 31
32#define ECB_GCC_VERSION(major,minor) (__GNUC__ > (major) || (__GNUC__ == (major) && __GNUC_MINOR__ >= (minor))) 32#define ECB_GCC_VERSION(major,minor) (__GNUC__ > (major) || (__GNUC__ == (major) && __GNUC_MINOR__ >= (minor)))
33 33
34#define ECB_HEADER_INLINE static inline
35
34#if ECB_GCC_VERSION(3,1) 36#if ECB_GCC_VERSION(3,1)
35# define ecb_attribute(attrlist) __attribute__(attrlist) 37# define ecb_attribute(attrlist) __attribute__(attrlist)
36# define ecb_is_constant(c) __builtin_constant_p (c) 38# define ecb_is_constant(c) __builtin_constant_p (c)
37# define ecb_expect(expr,value) __builtin_expect ((expr),(value)) 39# define ecb_expect(expr,value) __builtin_expect ((expr),(value))
38# define ecb_prefetch(addr,rw,locality) __builtin_prefetch (addr, rw, locality) 40# define ecb_prefetch(addr,rw,locality) __builtin_prefetch (addr, rw, locality)
… …
59#define ecb_cold ecb_attribute ((cold)) // 4.3 61#define ecb_cold ecb_attribute ((cold)) // 4.3
60 62
61#if ECB_GCC_VERSION(4,5) 63#if ECB_GCC_VERSION(4,5)
62# define ecb_unreachable() __builtin_unreachable () 64# define ecb_unreachable() __builtin_unreachable ()
63#else 65#else
64 // this seems to work fine, but gcc always emits a warning for it :/ 66 /* this seems to work fine, but gcc always emits a warning for it :/ */
65 static inline void ecb_unreachable () ecb_attribute ((noreturn)); 67 ECB_HEADER_INLINE void ecb_unreachable () ecb_attribute ((noreturn));
66 static inline void ecb_unreachable () { } 68 ECB_HEADER_INLINE void ecb_unreachable () { }
67#endif 69#endif
68 70
69// put into ifs if you are very sure that the expression 71/* put into ifs if you are very sure that the expression */
70// is mostly true or mosty false. note that these return 72/* is mostly true or mosty false. note that these return */
71// booleans, not the expression. 73/* booleans, not the expression. */
72#define ecb_expect_false(expr) ecb_expect ((expr) ? 1 : 0, 0) 74#define ecb_expect_false(expr) ecb_expect ((expr) ? 1 : 0, 0)
73#define ecb_expect_true(expr) ecb_expect ((expr) ? 1 : 0, 1) 75#define ecb_expect_true(expr) ecb_expect ((expr) ? 1 : 0, 1)
74 76
75// try to tell the compiler that some condition is definitely true 77/* try to tell the compiler that some condition is definitely true */
76#define ecb_assume(cond) do { if (!(cond)) unreachable (); } while (0) 78#define ecb_assume(cond) do { if (!(cond)) unreachable (); } while (0)
77 79
78// count trailing zero bits and count # of one bits 80/* count trailing zero bits and count # of one bits */
79#if ECB_GCC_VERSION(3,4) 81#if ECB_GCC_VERSION(3,4)
80static inline int ecb_ctz (unsigned int x) { return __builtin_ctz (x); } 82ECB_HEADER_INLINE int ecb_ctz (unsigned int x) { return __builtin_ctz (x); }
81static inline int ecb_popcount (unsigned int x) { return __builtin_popcount (x); } 83ECB_HEADER_INLINE int ecb_popcount (unsigned int x) { return __builtin_popcount (x); }
82#else 84#else
85ECB_HEADER_INLINE
83static int ecb_ctz (unsigned int x) ecb_const 86ecb_ctz (unsigned int x) ecb_const
84{ 87{
85 int r = 0; 88 int r = 0;
86 89
87 x &= -x; // this isolates the lowest bit 90 x &= -x; // this isolates the lowest bit
88 91
… …
93 if (x & 0xffff0000) r += 16; 96 if (x & 0xffff0000) r += 16;
94 97
95 return r; 98 return r;
96} 99}
97 100
101ECB_HEADER_INLINE
98static int ecb_popcount (unsigned int x) ecb_const 102ecb_popcount (unsigned int x) ecb_const
99{ 103{
100 x -= (x >> 1) & 0x55555555; 104 x -= (x >> 1) & 0x55555555;
101 x = ((x >> 2) & 0x33333333) + (x & 0x33333333); 105 x = ((x >> 2) & 0x33333333) + (x & 0x33333333);
102 x = ((x >> 4) + x) & 0x0f0f0f0f; 106 x = ((x >> 4) + x) & 0x0f0f0f0f;
103 x *= 0x01010101; 107 x *= 0x01010101;
104 108
105 return x >> 24; 109 return x >> 24;
106} 110}
107#endif 111#endif
108 112
113ECB_HEADER_INLINE unsigned char
114ecb_byteorder_helper () ecb_const
115{
116 const uint32_t u = 0x11223344;
117 return *(unsigned char *)&u;
118}
119
120ECB_HEADER_INLINE bool ecb_big_endian () ecb_const { return ecb_byteorder_helper () == 0x11; };
121ECB_HEADER_INLINE bool ecb_network () ecb_const { return big_endian (); };
122ECB_HEADER_INLINE bool ecb_little_endian () ecb_const { return ecb_byteorder_helper () == 0x44; };
123ECB_HEADER_INLINE bool ecb_vax () ecb_const { return little_endian (); };
124
125
109#endif 126#endif
110 127

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