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/cvs/libecb/ecb.h
Revision: 1.58
Committed: Wed Aug 3 15:40:18 2011 UTC (12 years, 10 months ago) by root
Content type: text/plain
Branch: MAIN
Changes since 1.57: +9 -0 lines
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# Content
1 /*
2 * libecb - http://software.schmorp.de/pkg/libecb
3 *
4 * Copyright (©) 2009-2011 Marc Alexander Lehmann <libecb@schmorp.de>
5 * Copyright (©) 2011 Emanuele Giaquinta
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without modifica-
9 * tion, are permitted provided that the following conditions are met:
10 *
11 * 1. Redistributions of source code must retain the above copyright notice,
12 * this list of conditions and the following disclaimer.
13 *
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
19 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MER-
20 * CHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
21 * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPE-
22 * CIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
23 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
24 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
25 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTH-
26 * ERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
27 * OF THE POSSIBILITY OF SUCH DAMAGE.
28 */
29
30 #ifndef ECB_H
31 #define ECB_H
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
62 #define ECB_GCC_VERSION(major,minor) (__GNUC__ > (major) || (__GNUC__ == (major) && __GNUC_MINOR__ >= (minor)))
63 #endif
64 #endif
65
66 /*****************************************************************************/
67
68 /* ECB_NO_THREADS - ecb is not used by multiple threads, ever */
69 /* ECB_NO_SMP - ecb might be used in multiple threads, but only on a single cpu */
70
71 #if ECB_NO_THREADS || ECB_NO_SMP
72 #define ECB_MEMORY_FENCE do { } while (0)
73 #define ECB_MEMORY_FENCE_ACQUIRE do { } while (0)
74 #define ECB_MEMORY_FENCE_RELEASE do { } while (0)
75 #endif
76
77 #ifndef ECB_MEMORY_FENCE
78 #if ECB_GCC_VERSION(2,5)
79 #if __x86
80 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("lock; orb $0, -1(%%esp)" : : : "memory")
81 #define ECB_MEMORY_FENCE_ACQUIRE ECB_MEMORY_FENCE /* non-lock xchg might be enough */
82 #define ECB_MEMORY_FENCE_RELEASE do { } while (0) /* unlikely to change in future cpus */
83 #elif __amd64
84 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("mfence" : : : "memory")
85 #define ECB_MEMORY_FENCE_ACQUIRE __asm__ __volatile__ ("lfence" : : : "memory")
86 #define ECB_MEMORY_FENCE_RELEASE __asm__ __volatile__ ("sfence") /* play safe - not needed in any current cpu */
87 #endif
88 #endif
89 #endif
90
91 #ifndef ECB_MEMORY_FENCE
92 #if ECB_GCC_VERSION(4,4)
93 #define ECB_MEMORY_FENCE __sync_synchronize ()
94 #define ECB_MEMORY_FENCE_ACQUIRE ({ char dummy = 0; __sync_lock_test_and_set (&dummy, 1); })
95 #define ECB_MEMORY_FENCE_RELEASE ({ char dummy = 1; __sync_lock_release (&dummy ); })
96 #elif _MSC_VER >= 1400 /* VC++ 2005 */
97 #pragma intrinsic(_ReadBarrier,_WriteBarrier,_ReadWriteBarrier)
98 #define ECB_MEMORY_FENCE _ReadWriteBarrier ()
99 #define ECB_MEMORY_FENCE_ACQUIRE _ReadWriteBarrier () /* according to msdn, _ReadBarrier is not a load fence */
100 #define ECB_MEMORY_FENCE_RELEASE _WriteBarrier ()
101 #elif defined(_WIN32)
102 #include <WinNT.h>
103 #define ECB_MEMORY_FENCE MemoryBarrier () /* actually just xchg on x86... scary */
104 #define ECB_MEMORY_FENCE_ACQUIRE ECB_MEMORY_FENCE
105 #define ECB_MEMORY_FENCE_RELEASE ECB_MEMORY_FENCE
106 #endif
107 #endif
108
109 #ifndef ECB_MEMORY_FENCE
110 /*
111 * if you get undefined symbol references to pthread_mutex_lock,
112 * or failure to find pthread.h, then you should implement
113 * the ECB_MEMORY_FENCE operations for your cpu/compiler
114 * OR proide pthread.h and link against the posix thread library
115 * of your system.
116 */
117 #include <pthread.h>
118
119 static pthread_mutex_t ecb_mf_lock = PTHREAD_MUTEX_INITIALIZER;
120 #define ECB_MEMORY_FENCE do { pthread_mutex_lock (&ecb_mf_lock); pthread_mutex_unlock (&ecb_mf_lock); } while (0)
121 #define ECB_MEMORY_FENCE_ACQUIRE ECB_MEMORY_FENCE
122 #define ECB_MEMORY_FENCE_RELEASE ECB_MEMORY_FENCE
123 #endif
124
125 /*****************************************************************************/
126
127 #define ECB_C99 (__STDC_VERSION__ >= 199901L)
128
129 #if __cplusplus
130 #define ecb_inline static inline
131 #elif ECB_GCC_VERSION(2,5)
132 #define ecb_inline static __inline__
133 #elif ECB_C99
134 #define ecb_inline static inline
135 #else
136 #define ecb_inline static
137 #endif
138
139 #if ECB_GCC_VERSION(3,3)
140 #define ecb_restrict __restrict__
141 #elif ECB_C99
142 #define ecb_restrict restrict
143 #else
144 #define ecb_restrict
145 #endif
146
147 typedef int ecb_bool;
148
149 #define ECB_CONCAT_(a, b) a ## b
150 #define ECB_CONCAT(a, b) ECB_CONCAT_(a, b)
151 #define ECB_STRINGIFY_(a) # a
152 #define ECB_STRINGIFY(a) ECB_STRINGIFY_(a)
153
154 #define ecb_function_ ecb_inline
155
156 #if ECB_GCC_VERSION(3,1)
157 #define ecb_attribute(attrlist) __attribute__(attrlist)
158 #define ecb_is_constant(expr) __builtin_constant_p (expr)
159 #define ecb_expect(expr,value) __builtin_expect ((expr),(value))
160 #define ecb_prefetch(addr,rw,locality) __builtin_prefetch (addr, rw, locality)
161 #else
162 #define ecb_attribute(attrlist)
163 #define ecb_is_constant(expr) 0
164 #define ecb_expect(expr,value) (expr)
165 #define ecb_prefetch(addr,rw,locality)
166 #endif
167
168 /* no emulation for ecb_decltype */
169 #if ECB_GCC_VERSION(4,5)
170 #define ecb_decltype(x) __decltype(x)
171 #elif ECB_GCC_VERSION(3,0)
172 #define ecb_decltype(x) __typeof(x)
173 #endif
174
175 #define ecb_noinline ecb_attribute ((__noinline__))
176 #define ecb_noreturn ecb_attribute ((__noreturn__))
177 #define ecb_unused ecb_attribute ((__unused__))
178 #define ecb_const ecb_attribute ((__const__))
179 #define ecb_pure ecb_attribute ((__pure__))
180
181 #if ECB_GCC_VERSION(4,3)
182 #define ecb_artificial ecb_attribute ((__artificial__))
183 #define ecb_hot ecb_attribute ((__hot__))
184 #define ecb_cold ecb_attribute ((__cold__))
185 #else
186 #define ecb_artificial
187 #define ecb_hot
188 #define ecb_cold
189 #endif
190
191 /* put around conditional expressions if you are very sure that the */
192 /* expression is mostly true or mostly false. note that these return */
193 /* booleans, not the expression. */
194 #define ecb_expect_false(expr) ecb_expect (!!(expr), 0)
195 #define ecb_expect_true(expr) ecb_expect (!!(expr), 1)
196 /* for compatibility to the rest of the world */
197 #define ecb_likely(expr) ecb_expect_true (expr)
198 #define ecb_unlikely(expr) ecb_expect_false (expr)
199
200 /* count trailing zero bits and count # of one bits */
201 #if ECB_GCC_VERSION(3,4)
202 /* we assume int == 32 bit, long == 32 or 64 bit and long long == 64 bit */
203 #define ecb_ld32(x) (__builtin_clz (x) ^ 31)
204 #define ecb_ld64(x) (__builtin_clzll (x) ^ 63)
205 #define ecb_ctz32(x) __builtin_ctz (x)
206 #define ecb_ctz64(x) __builtin_ctzll (x)
207 #define ecb_popcount32(x) __builtin_popcount (x)
208 /* no popcountll */
209 #else
210 ecb_function_ int ecb_ctz32 (uint32_t x) ecb_const;
211 ecb_function_ int
212 ecb_ctz32 (uint32_t x)
213 {
214 int r = 0;
215
216 x &= ~x + 1; /* this isolates the lowest bit */
217
218 #if ECB_branchless_on_i386
219 r += !!(x & 0xaaaaaaaa) << 0;
220 r += !!(x & 0xcccccccc) << 1;
221 r += !!(x & 0xf0f0f0f0) << 2;
222 r += !!(x & 0xff00ff00) << 3;
223 r += !!(x & 0xffff0000) << 4;
224 #else
225 if (x & 0xaaaaaaaa) r += 1;
226 if (x & 0xcccccccc) r += 2;
227 if (x & 0xf0f0f0f0) r += 4;
228 if (x & 0xff00ff00) r += 8;
229 if (x & 0xffff0000) r += 16;
230 #endif
231
232 return r;
233 }
234
235 ecb_function_ int ecb_ctz64 (uint64_t x) ecb_const;
236 ecb_function_ int
237 ecb_ctz64 (uint64_t x)
238 {
239 int shift = x & 0xffffffffU ? 0 : 32;
240 return ecb_ctz32 (x >> shift) + shift;
241 }
242
243 ecb_function_ int ecb_popcount32 (uint32_t x) ecb_const;
244 ecb_function_ int
245 ecb_popcount32 (uint32_t x)
246 {
247 x -= (x >> 1) & 0x55555555;
248 x = ((x >> 2) & 0x33333333) + (x & 0x33333333);
249 x = ((x >> 4) + x) & 0x0f0f0f0f;
250 x *= 0x01010101;
251
252 return x >> 24;
253 }
254
255 ecb_function_ int ecb_ld32 (uint32_t x) ecb_const;
256 ecb_function_ int ecb_ld32 (uint32_t x)
257 {
258 int r = 0;
259
260 if (x >> 16) { x >>= 16; r += 16; }
261 if (x >> 8) { x >>= 8; r += 8; }
262 if (x >> 4) { x >>= 4; r += 4; }
263 if (x >> 2) { x >>= 2; r += 2; }
264 if (x >> 1) { r += 1; }
265
266 return r;
267 }
268
269 ecb_function_ int ecb_ld64 (uint64_t x) ecb_const;
270 ecb_function_ int ecb_ld64 (uint64_t x)
271 {
272 int r = 0;
273
274 if (x >> 32) { x >>= 32; r += 32; }
275
276 return r + ecb_ld32 (x);
277 }
278 #endif
279
280 /* popcount64 is only available on 64 bit cpus as gcc builtin */
281 /* so for this version we are lazy */
282 ecb_function_ int ecb_popcount64 (uint64_t x) ecb_const;
283 ecb_function_ int
284 ecb_popcount64 (uint64_t x)
285 {
286 return ecb_popcount32 (x) + ecb_popcount32 (x >> 32);
287 }
288
289 ecb_inline uint8_t ecb_rotl8 (uint8_t x, unsigned int count) ecb_const;
290 ecb_inline uint8_t ecb_rotr8 (uint8_t x, unsigned int count) ecb_const;
291 ecb_inline uint16_t ecb_rotl16 (uint16_t x, unsigned int count) ecb_const;
292 ecb_inline uint16_t ecb_rotr16 (uint16_t x, unsigned int count) ecb_const;
293 ecb_inline uint32_t ecb_rotl32 (uint32_t x, unsigned int count) ecb_const;
294 ecb_inline uint32_t ecb_rotr32 (uint32_t x, unsigned int count) ecb_const;
295 ecb_inline uint64_t ecb_rotl64 (uint64_t x, unsigned int count) ecb_const;
296 ecb_inline uint64_t ecb_rotr64 (uint64_t x, unsigned int count) ecb_const;
297
298 ecb_inline uint8_t ecb_rotl8 (uint8_t x, unsigned int count) { return (x >> ( 8 - count)) | (x << count); }
299 ecb_inline uint8_t ecb_rotr8 (uint8_t x, unsigned int count) { return (x << ( 8 - count)) | (x >> count); }
300 ecb_inline uint16_t ecb_rotl16 (uint16_t x, unsigned int count) { return (x >> (16 - count)) | (x << count); }
301 ecb_inline uint16_t ecb_rotr16 (uint16_t x, unsigned int count) { return (x << (16 - count)) | (x >> count); }
302 ecb_inline uint32_t ecb_rotl32 (uint32_t x, unsigned int count) { return (x >> (32 - count)) | (x << count); }
303 ecb_inline uint32_t ecb_rotr32 (uint32_t x, unsigned int count) { return (x << (32 - count)) | (x >> count); }
304 ecb_inline uint64_t ecb_rotl64 (uint64_t x, unsigned int count) { return (x >> (64 - count)) | (x << count); }
305 ecb_inline uint64_t ecb_rotr64 (uint64_t x, unsigned int count) { return (x << (64 - count)) | (x >> count); }
306
307 #if ECB_GCC_VERSION(4,3)
308 #define ecb_bswap16(x) (__builtin_bswap32 (x) >> 16)
309 #define ecb_bswap32(x) __builtin_bswap32 (x)
310 #define ecb_bswap64(x) __builtin_bswap64 (x)
311 #else
312 ecb_function_ uint16_t ecb_bswap16 (uint16_t x) ecb_const;
313 ecb_function_ uint16_t
314 ecb_bswap16 (uint16_t x)
315 {
316 return ecb_rotl16 (x, 8);
317 }
318
319 ecb_function_ uint32_t ecb_bswap32 (uint32_t x) ecb_const;
320 ecb_function_ uint32_t
321 ecb_bswap32 (uint32_t x)
322 {
323 return (((uint32_t)ecb_bswap16 (x)) << 16) | ecb_bswap16 (x >> 16);
324 }
325
326 ecb_function_ uint64_t ecb_bswap64 (uint64_t x) ecb_const;
327 ecb_function_ uint64_t
328 ecb_bswap64 (uint64_t x)
329 {
330 return (((uint64_t)ecb_bswap32 (x)) << 32) | ecb_bswap32 (x >> 32);
331 }
332 #endif
333
334 #if ECB_GCC_VERSION(4,5)
335 #define ecb_unreachable() __builtin_unreachable ()
336 #else
337 /* this seems to work fine, but gcc always emits a warning for it :/ */
338 ecb_function_ void ecb_unreachable (void) ecb_noreturn;
339 ecb_function_ void ecb_unreachable (void) { }
340 #endif
341
342 /* try to tell the compiler that some condition is definitely true */
343 #define ecb_assume(cond) do { if (!(cond)) ecb_unreachable (); } while (0)
344
345 ecb_function_ unsigned char ecb_byteorder_helper (void) ecb_const;
346 ecb_function_ unsigned char
347 ecb_byteorder_helper (void)
348 {
349 const uint32_t u = 0x11223344;
350 return *(unsigned char *)&u;
351 }
352
353 ecb_function_ ecb_bool ecb_big_endian (void) ecb_const;
354 ecb_function_ ecb_bool ecb_big_endian (void) { return ecb_byteorder_helper () == 0x11; }
355 ecb_function_ ecb_bool ecb_little_endian (void) ecb_const;
356 ecb_function_ ecb_bool ecb_little_endian (void) { return ecb_byteorder_helper () == 0x44; }
357
358 #if ECB_GCC_VERSION(3,0) || ECB_C99
359 #define ecb_mod(m,n) ((m) % (n) + ((m) % (n) < 0 ? (n) : 0))
360 #else
361 #define ecb_mod(m,n) ((m) < 0 ? ((n) - 1 - ((-1 - (m)) % (n))) : ((m) % (n)))
362 #endif
363
364 #if ecb_cplusplus_does_not_suck
365 /* does not work for local types (http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2657.htm) */
366 template<typename T, int N>
367 static inline int ecb_array_length (const T (&arr)[N])
368 {
369 return N;
370 }
371 #else
372 #define ecb_array_length(name) (sizeof (name) / sizeof (name [0]))
373 #endif
374
375 #endif
376