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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 1.4 by root, Thu May 26 17:26:03 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#ifndef __cplusplus
35# if __STDC_VERSION__ >= 199901L
36# define ECB_INLINE inline
37typedef _Bool ecb_bool;
38# else
39# define ECB_INLINE inline /* yeah! */
40typedef int ecb_bool;
41# endif
42#endif
43
44#define ECB_HEADER_INLINE static ECB_INLINE
45
34#if ECB_GCC_VERSION(3,1) 46#if ECB_GCC_VERSION(3,1)
35# define ecb_attribute(attrlist) __attribute__(attrlist) 47# define ecb_attribute(attrlist) __attribute__(attrlist)
36# define ecb_is_constant(c) __builtin_constant_p (c) 48# define ecb_is_constant(c) __builtin_constant_p (c)
37# define ecb_expect(expr,value) __builtin_expect ((expr),(value)) 49# define ecb_expect(expr,value) __builtin_expect ((expr),(value))
38# define ecb_prefetch(addr,rw,locality) __builtin_prefetch (addr, rw, locality) 50# define ecb_prefetch(addr,rw,locality) __builtin_prefetch (addr, rw, locality)
… …
53#define ecb_noinline ecb_attribute ((noinline)) 65#define ecb_noinline ecb_attribute ((noinline))
54#define ecb_noreturn ecb_attribute ((noreturn)) 66#define ecb_noreturn ecb_attribute ((noreturn))
55#define ecb_unused ecb_attribute ((unused)) 67#define ecb_unused ecb_attribute ((unused))
56#define ecb_const ecb_attribute ((const)) 68#define ecb_const ecb_attribute ((const))
57#define ecb_pure ecb_attribute ((pure)) 69#define ecb_pure ecb_attribute ((pure))
58#define ecb_hot ecb_attribute ((hot)) // 4.3 70#define ecb_hot ecb_attribute ((hot)) /* 4.3 */
59#define ecb_cold ecb_attribute ((cold)) // 4.3 71#define ecb_cold ecb_attribute ((cold)) /* 4.3 */
60 72
61#if ECB_GCC_VERSION(4,5) 73#if ECB_GCC_VERSION(4,5)
62# define ecb_unreachable() __builtin_unreachable () 74# define ecb_unreachable() __builtin_unreachable ()
63#else 75#else
64 // this seems to work fine, but gcc always emits a warning for it :/ 76/* this seems to work fine, but gcc always emits a warning for it :/ */
65 static inline void ecb_unreachable () ecb_attribute ((noreturn)); 77ECB_HEADER_INLINE void ecb_unreachable () ecb_attribute ((noreturn));
66 static inline void ecb_unreachable () { } 78ECB_HEADER_INLINE void ecb_unreachable () { }
67#endif 79#endif
68 80
69// put into ifs if you are very sure that the expression 81/* put into ifs if you are very sure that the expression */
70// is mostly true or mosty false. note that these return 82/* is mostly true or mosty false. note that these return */
71// booleans, not the expression. 83/* booleans, not the expression. */
72#define ecb_expect_false(expr) ecb_expect ((expr) ? 1 : 0, 0) 84#define ecb_expect_false(expr) ecb_expect ((expr) ? 1 : 0, 0)
73#define ecb_expect_true(expr) ecb_expect ((expr) ? 1 : 0, 1) 85#define ecb_expect_true(expr) ecb_expect ((expr) ? 1 : 0, 1)
74 86
75// try to tell the compiler that some condition is definitely true 87/* try to tell the compiler that some condition is definitely true */
76#define ecb_assume(cond) do { if (!(cond)) unreachable (); } while (0) 88#define ecb_assume(cond) do { if (!(cond)) unreachable (); } while (0)
77 89
78// count trailing zero bits and count # of one bits 90/* count trailing zero bits and count # of one bits */
79#if ECB_GCC_VERSION(3,4) 91#if ECB_GCC_VERSION(3,4)
80static inline int ecb_ctz (unsigned int x) { return __builtin_ctz (x); } 92ECB_HEADER_INLINE int ecb_ctz32 (unsigned int x) { return __builtin_ctz (x); }
81static inline int ecb_popcount (unsigned int x) { return __builtin_popcount (x); } 93ECB_HEADER_INLINE int ecb_popcount32 (unsigned int x) { return __builtin_popcount (x); }
82#else 94#else
95ECB_HEADER_INLINE
83static int ecb_ctz (unsigned int x) ecb_const 96ecb_ctz32 (unsigned int x) ecb_const
84{ 97{
85 int r = 0; 98 int r = 0;
86 99
87 x &= -x; // this isolates the lowest bit 100 x &= -x; /* this isolates the lowest bit */
88 101
89 if (x & 0xaaaaaaaa) r += 1; 102 if (x & 0xaaaaaaaa) r += 1;
90 if (x & 0xcccccccc) r += 2; 103 if (x & 0xcccccccc) r += 2;
91 if (x & 0xf0f0f0f0) r += 4; 104 if (x & 0xf0f0f0f0) r += 4;
92 if (x & 0xff00ff00) r += 8; 105 if (x & 0xff00ff00) r += 8;
93 if (x & 0xffff0000) r += 16; 106 if (x & 0xffff0000) r += 16;
94 107
95 return r; 108 return r;
96} 109}
97 110
111ECB_HEADER_INLINE
98static int ecb_popcount (unsigned int x) ecb_const 112ecb_popcount32 (unsigned int x) ecb_const
99{ 113{
100 x -= (x >> 1) & 0x55555555; 114 x -= (x >> 1) & 0x55555555;
101 x = ((x >> 2) & 0x33333333) + (x & 0x33333333); 115 x = ((x >> 2) & 0x33333333) + (x & 0x33333333);
102 x = ((x >> 4) + x) & 0x0f0f0f0f; 116 x = ((x >> 4) + x) & 0x0f0f0f0f;
103 x *= 0x01010101; 117 x *= 0x01010101;
104 118
105 return x >> 24; 119 return x >> 24;
106} 120}
107#endif 121#endif
108 122
123ECB_HEADER_INLINE unsigned char
124ecb_byteorder_helper () ecb_const
125{
126 const uint32_t u = 0x11223344;
127 return *(unsigned char *)&u;
128}
129
130ECB_HEADER_INLINE ecb_bool ecb_big_endian () ecb_const { return ecb_byteorder_helper () == 0x11; };
131ECB_HEADER_INLINE ecb_bool ecb_little_endian () ecb_const { return ecb_byteorder_helper () == 0x44; };
132
109#endif 133#endif
110 134

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