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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 1.55 by root, Tue Jul 26 09:59:36 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#ifdef _WIN32
34 typedef signed char int8_t;
35 typedef unsigned char uint8_t;
36 typedef signed short int16_t;
37 typedef unsigned short uint16_t;
38 typedef signed int int32_t;
39 typedef unsigned int uint32_t;
40 #if __GNUC__
41 typedef signed long long int64_t;
42 typedef unsigned long long uint64_t;
43 #else /* _MSC_VER || __BORLANDC__ */
44 typedef signed __int64 int64_t;
45 typedef unsigned __int64 uint64_t;
46 #endif
47#else
48 #include <inttypes.h>
49#endif
50
51/* many compilers define _GNUC_ to some versions but then only implement
52 * what their idiot authors think are the "more important" extensions,
53 * causing enourmous grief in return for some better fake benchmark numbers.
54 * or so.
55 * we try to detect these and simply assume they are not gcc - if they have
56 * an issue with that they should have done it right in the first place.
57 */
58#ifndef ECB_GCC_VERSION
59 #if !defined(__GNUC_MINOR__) || defined(__INTEL_COMPILER) || defined(__SUNPRO_C) || defined(__SUNPRO_CC) || defined(__llvm__) || defined(__clang__)
60 #define ECB_GCC_VERSION(major,minor) 0
61 #else
32#define ECB_GCC_VERSION(major,minor) (__GNUC__ > (major) || (__GNUC__ == (major) && __GNUC_MINOR__ >= (minor))) 62 #define ECB_GCC_VERSION(major,minor) (__GNUC__ > (major) || (__GNUC__ == (major) && __GNUC_MINOR__ >= (minor)))
63 #endif
64#endif
65
66/*****************************************************************************/
67
68#ifndef ECB_MEMORY_FENCE
69 #if ECB_GCC_VERSION(2,5)
70 #if __x86
71 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("lock; orb $0, -1(%%esp)" : : : "memory")
72 #define ECB_MEMORY_FENCE_ACQUIRE ECB_MEMORY_FENCE
73 #define ECB_MEMORY_FENCE_RELEASE ECB_MEMORY_FENCE /* better be safe than sorry */
74 #elif __amd64
75 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("mfence" : : : "memory")
76 #define ECB_MEMORY_FENCE_ACQUIRE __asm__ __volatile__ ("lfence" : : : "memory")
77 #define ECB_MEMORY_FENCE_RELEASE __asm__ __volatile__ ("sfence")
78 #endif
79 #endif
80#endif
81
82#ifndef ECB_MEMORY_FENCE
83 #if ECB_GCC_VERSION(4,4)
84 #define ECB_MEMORY_FENCE __sync_synchronize ()
85 #define ECB_MEMORY_FENCE_ACQUIRE ({ char dummy = 0; __sync_lock_test_and_set (&dummy, 1); })
86 #define ECB_MEMORY_FENCE_RELEASE ({ char dummy = 1; __sync_lock_release (&dummy ); })
87 #elif _MSC_VER >= 1400 && 0 /* TODO: only true when using volatiles */
88 #define ECB_MEMORY_FENCE do { } while (0)
89 #define ECB_MEMORY_FENCE_ACQUIRE ECB_MEMORY_FENCE
90 #define ECB_MEMORY_FENCE_RELEASE ECB_MEMORY_FENCE
91 #elif defined(_WIN32)
92 #include <WinNT.h>
93 #define ECB_MEMORY_FENCE MemoryBarrier ()
94 #define ECB_MEMORY_FENCE_ACQUIRE ECB_MEMORY_FENCE
95 #define ECB_MEMORY_FENCE_RELEASE ECB_MEMORY_FENCE
96 #endif
97#endif
98
99#ifndef ECB_MEMORY_FENCE
100 #include <pthread.h>
101
102 static pthread_mutex_t ecb_mf_lock = PTHREAD_MUTEX_INITIALIZER;
103 #define ECB_MEMORY_FENCE do { pthread_mutex_lock (&ecb_mf_lock); pthread_mutex_unlock (&ecb_mf_lock); } while (0)
104 #define ECB_MEMORY_FENCE_ACQUIRE ECB_MEMORY_FENCE
105 #define ECB_MEMORY_FENCE_RELEASE ECB_MEMORY_FENCE
106#endif
107
108/*****************************************************************************/
109
110#define ECB_C99 (__STDC_VERSION__ >= 199901L)
111
112#if __cplusplus
113 #define ecb_inline static inline
114#elif ECB_GCC_VERSION(2,5)
115 #define ecb_inline static __inline__
116#elif ECB_C99
117 #define ecb_inline static inline
118#else
119 #define ecb_inline static
120#endif
121
122#if ECB_GCC_VERSION(3,3)
123 #define ecb_restrict __restrict__
124#elif ECB_C99
125 #define ecb_restrict restrict
126#else
127 #define ecb_restrict
128#endif
129
130typedef int ecb_bool;
131
132#define ECB_CONCAT_(a, b) a ## b
133#define ECB_CONCAT(a, b) ECB_CONCAT_(a, b)
134#define ECB_STRINGIFY_(a) # a
135#define ECB_STRINGIFY(a) ECB_STRINGIFY_(a)
136
137#define ecb_function_ ecb_inline
33 138
34#if ECB_GCC_VERSION(3,1) 139#if ECB_GCC_VERSION(3,1)
35# define ecb_attribute(attrlist) __attribute__(attrlist) 140 #define ecb_attribute(attrlist) __attribute__(attrlist)
36# define ecb_is_constant(c) __builtin_constant_p (c) 141 #define ecb_is_constant(expr) __builtin_constant_p (expr)
37# define ecb_expect(expr,value) __builtin_expect ((expr),(value)) 142 #define ecb_expect(expr,value) __builtin_expect ((expr),(value))
38# define ecb_prefetch(addr,rw,locality) __builtin_prefetch (addr, rw, locality) 143 #define ecb_prefetch(addr,rw,locality) __builtin_prefetch (addr, rw, locality)
39#else 144#else
40# define ecb_attribute(attrlist) 145 #define ecb_attribute(attrlist)
41# define ecb_is_constant(c) 0 146 #define ecb_is_constant(expr) 0
42# define ecb_expect(expr,value) (expr) 147 #define ecb_expect(expr,value) (expr)
43# define ecb_prefetch(addr,rw,locality) 148 #define ecb_prefetch(addr,rw,locality)
44#endif 149#endif
45 150
151/* no emulation for ecb_decltype */
46#if ECB_GCC_VERSION(4,5) 152#if ECB_GCC_VERSION(4,5)
47# define ecb_decltype(x) __decltype(x) 153 #define ecb_decltype(x) __decltype(x)
48#elif ECB_GCC_VERSION(3,0) 154#elif ECB_GCC_VERSION(3,0)
49# define ecb_decltype(x) typeof(x) 155 #define ecb_decltype(x) __typeof(x)
50#endif 156#endif
51 157
52#define ecb_noinline ecb_attribute ((noinline)) 158#define ecb_noinline ecb_attribute ((__noinline__))
53#define ecb_noreturn ecb_attribute ((noreturn)) 159#define ecb_noreturn ecb_attribute ((__noreturn__))
54#define ecb_unused ecb_attribute ((unused)) 160#define ecb_unused ecb_attribute ((__unused__))
55#define ecb_const ecb_attribute ((const)) 161#define ecb_const ecb_attribute ((__const__))
56#define ecb_pure ecb_attribute ((pure)) 162#define ecb_pure ecb_attribute ((__pure__))
163
164#if ECB_GCC_VERSION(4,3)
165 #define ecb_artificial ecb_attribute ((__artificial__))
57#define ecb_hot ecb_attribute ((hot)) // 4.3 166 #define ecb_hot ecb_attribute ((__hot__))
58#define ecb_cold ecb_attribute ((cold)) // 4.3 167 #define ecb_cold ecb_attribute ((__cold__))
168#else
169 #define ecb_artificial
170 #define ecb_hot
171 #define ecb_cold
172#endif
173
174/* put around conditional expressions if you are very sure that the */
175/* expression is mostly true or mostly false. note that these return */
176/* booleans, not the expression. */
177#define ecb_expect_false(expr) ecb_expect (!!(expr), 0)
178#define ecb_expect_true(expr) ecb_expect (!!(expr), 1)
179/* for compatibility to the rest of the world */
180#define ecb_likely(expr) ecb_expect_true (expr)
181#define ecb_unlikely(expr) ecb_expect_false (expr)
182
183/* count trailing zero bits and count # of one bits */
184#if ECB_GCC_VERSION(3,4)
185 /* we assume int == 32 bit, long == 32 or 64 bit and long long == 64 bit */
186 #define ecb_ld32(x) (__builtin_clz (x) ^ 31)
187 #define ecb_ld64(x) (__builtin_clzll (x) ^ 63)
188 #define ecb_ctz32(x) __builtin_ctz (x)
189 #define ecb_ctz64(x) __builtin_ctzll (x)
190 #define ecb_popcount32(x) __builtin_popcount (x)
191 /* no popcountll */
192#else
193 ecb_function_ int ecb_ctz32 (uint32_t x) ecb_const;
194 ecb_function_ int
195 ecb_ctz32 (uint32_t x)
196 {
197 int r = 0;
198
199 x &= ~x + 1; /* this isolates the lowest bit */
200
201#if ECB_branchless_on_i386
202 r += !!(x & 0xaaaaaaaa) << 0;
203 r += !!(x & 0xcccccccc) << 1;
204 r += !!(x & 0xf0f0f0f0) << 2;
205 r += !!(x & 0xff00ff00) << 3;
206 r += !!(x & 0xffff0000) << 4;
207#else
208 if (x & 0xaaaaaaaa) r += 1;
209 if (x & 0xcccccccc) r += 2;
210 if (x & 0xf0f0f0f0) r += 4;
211 if (x & 0xff00ff00) r += 8;
212 if (x & 0xffff0000) r += 16;
213#endif
214
215 return r;
216 }
217
218 ecb_function_ int ecb_ctz64 (uint64_t x) ecb_const;
219 ecb_function_ int
220 ecb_ctz64 (uint64_t x)
221 {
222 int shift = x & 0xffffffffU ? 0 : 32;
223 return ecb_ctz32 (x >> shift) + shift;
224 }
225
226 ecb_function_ int ecb_popcount32 (uint32_t x) ecb_const;
227 ecb_function_ int
228 ecb_popcount32 (uint32_t x)
229 {
230 x -= (x >> 1) & 0x55555555;
231 x = ((x >> 2) & 0x33333333) + (x & 0x33333333);
232 x = ((x >> 4) + x) & 0x0f0f0f0f;
233 x *= 0x01010101;
234
235 return x >> 24;
236 }
237
238 /* you have the choice beetween something with a table lookup, */
239 /* something using lots of bit arithmetic and a simple loop */
240 /* we went for the loop */
241 ecb_function_ int ecb_ld32 (uint32_t x) ecb_const;
242 ecb_function_ int ecb_ld32 (uint32_t x)
243 {
244 int r = 0;
245
246 if (x >> 16) { x >>= 16; r += 16; }
247 if (x >> 8) { x >>= 8; r += 8; }
248 if (x >> 4) { x >>= 4; r += 4; }
249 if (x >> 2) { x >>= 2; r += 2; }
250 if (x >> 1) { r += 1; }
251
252 return r;
253 }
254
255 ecb_function_ int ecb_ld64 (uint64_t x) ecb_const;
256 ecb_function_ int ecb_ld64 (uint64_t x)
257 {
258 int r = 0;
259
260 if (x >> 32) { x >>= 32; r += 32; }
261
262 return r + ecb_ld32 (x);
263 }
264#endif
265
266/* popcount64 is only available on 64 bit cpus as gcc builtin */
267/* so for this version we are lazy */
268ecb_function_ int ecb_popcount64 (uint64_t x) ecb_const;
269ecb_function_ int
270ecb_popcount64 (uint64_t x)
271{
272 return ecb_popcount32 (x) + ecb_popcount32 (x >> 32);
273}
274
275ecb_inline uint8_t ecb_rotl8 (uint8_t x, unsigned int count) ecb_const;
276ecb_inline uint8_t ecb_rotr8 (uint8_t x, unsigned int count) ecb_const;
277ecb_inline uint16_t ecb_rotl16 (uint16_t x, unsigned int count) ecb_const;
278ecb_inline uint16_t ecb_rotr16 (uint16_t x, unsigned int count) ecb_const;
279ecb_inline uint32_t ecb_rotl32 (uint32_t x, unsigned int count) ecb_const;
280ecb_inline uint32_t ecb_rotr32 (uint32_t x, unsigned int count) ecb_const;
281ecb_inline uint64_t ecb_rotl64 (uint64_t x, unsigned int count) ecb_const;
282ecb_inline uint64_t ecb_rotr64 (uint64_t x, unsigned int count) ecb_const;
283
284ecb_inline uint8_t ecb_rotl8 (uint8_t x, unsigned int count) { return (x >> ( 8 - count)) | (x << count); }
285ecb_inline uint8_t ecb_rotr8 (uint8_t x, unsigned int count) { return (x << ( 8 - count)) | (x >> count); }
286ecb_inline uint16_t ecb_rotl16 (uint16_t x, unsigned int count) { return (x >> (16 - count)) | (x << count); }
287ecb_inline uint16_t ecb_rotr16 (uint16_t x, unsigned int count) { return (x << (16 - count)) | (x >> count); }
288ecb_inline uint32_t ecb_rotl32 (uint32_t x, unsigned int count) { return (x >> (32 - count)) | (x << count); }
289ecb_inline uint32_t ecb_rotr32 (uint32_t x, unsigned int count) { return (x << (32 - count)) | (x >> count); }
290ecb_inline uint64_t ecb_rotl64 (uint64_t x, unsigned int count) { return (x >> (64 - count)) | (x << count); }
291ecb_inline uint64_t ecb_rotr64 (uint64_t x, unsigned int count) { return (x << (64 - count)) | (x >> count); }
292
293#if ECB_GCC_VERSION(4,3)
294 #define ecb_bswap16(x) (__builtin_bswap32 (x) >> 16)
295 #define ecb_bswap32(x) __builtin_bswap32 (x)
296 #define ecb_bswap64(x) __builtin_bswap64 (x)
297#else
298 ecb_function_ uint16_t ecb_bswap16 (uint16_t x) ecb_const;
299 ecb_function_ uint16_t
300 ecb_bswap16 (uint16_t x)
301 {
302 return ecb_rotl16 (x, 8);
303 }
304
305 ecb_function_ uint32_t ecb_bswap32 (uint32_t x) ecb_const;
306 ecb_function_ uint32_t
307 ecb_bswap32 (uint32_t x)
308 {
309 return (((uint32_t)ecb_bswap16 (x)) << 16) | ecb_bswap16 (x >> 16);
310 }
311
312 ecb_function_ uint64_t ecb_bswap64 (uint64_t x) ecb_const;
313 ecb_function_ uint64_t
314 ecb_bswap64 (uint64_t x)
315 {
316 return (((uint64_t)ecb_bswap32 (x)) << 32) | ecb_bswap32 (x >> 32);
317 }
318#endif
59 319
60#if ECB_GCC_VERSION(4,5) 320#if ECB_GCC_VERSION(4,5)
61# define ecb_unreachable() __builtin_unreachable () 321 #define ecb_unreachable() __builtin_unreachable ()
62#else 322#else
63 // this seems to work fine, but gcc always emits a warning for it :/ 323 /* this seems to work fine, but gcc always emits a warning for it :/ */
64 static inline void ecb_unreachable () ecb_attribute ((noreturn)); 324 ecb_function_ void ecb_unreachable (void) ecb_noreturn;
65 static inline void ecb_unreachable () { } 325 ecb_function_ void ecb_unreachable (void) { }
66#endif 326#endif
67 327
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 328/* try to tell the compiler that some condition is definitely true */
75#define ecb_assume(cond) do { if (!(cond)) unreachable (); } while (0) 329#define ecb_assume(cond) do { if (!(cond)) ecb_unreachable (); } while (0)
76 330
77// count trailing zero bits and count # of one bits 331ecb_function_ unsigned char ecb_byteorder_helper (void) ecb_const;
78#if ECB_GCC_VERSION(3,4) 332ecb_function_ unsigned char
79static inline int ecb_ctz (unsigned int x) { return __builtin_ctz (x); } 333ecb_byteorder_helper (void)
80static inline int ecb_popcount (unsigned int x) { return __builtin_popcount (x); }
81#else
82static int ecb_ctz (unsigned int x) ecb_const
83{ 334{
84 int r = 0; 335 const uint32_t u = 0x11223344;
85 336 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} 337}
96 338
97static int ecb_popcount (unsigned int x) ecb_const 339ecb_function_ ecb_bool ecb_big_endian (void) ecb_const;
98{ 340ecb_function_ ecb_bool ecb_big_endian (void) { return ecb_byteorder_helper () == 0x11; }
99 x -= (x >> 1) & 0x55555555; 341ecb_function_ ecb_bool ecb_little_endian (void) ecb_const;
100 x = ((x >> 2) & 0x33333333) + (x & 0x33333333); 342ecb_function_ ecb_bool ecb_little_endian (void) { return ecb_byteorder_helper () == 0x44; }
101 x = ((x >> 4) + x) & 0x0f0f0f0f;
102 x *= 0x01010101;
103 343
104 return x >> 24; 344#if ECB_GCC_VERSION(3,0) || ECB_C99
105} 345 #define ecb_mod(m,n) ((m) % (n) + ((m) % (n) < 0 ? (n) : 0))
346#else
347 #define ecb_mod(m,n) ((m) < 0 ? ((n) - 1 - ((-1 - (m)) % (n))) : ((m) % (n)))
106#endif 348#endif
107 349
350#if ecb_cplusplus_does_not_suck
351 /* does not work for local types (http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2657.htm) */
352 template<typename T, int N>
353 static inline int ecb_array_length (const T (&arr)[N])
354 {
355 return N;
356 }
357#else
358 #define ecb_array_length(name) (sizeof (name) / sizeof (name [0]))
108#endif 359#endif
109 360
361#endif
362

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