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Revision: 1.93
Committed: Tue May 29 19:10:50 2012 UTC (12 years ago) by root
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Branch: MAIN
Changes since 1.92: +15 -10 lines
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# Content
1 /*
2 * libecb - http://software.schmorp.de/pkg/libecb
3 *
4 * Copyright (©) 2009-2012 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 /* 16 bits major, 16 bits minor */
34 #define ECB_VERSION 0x00010001
35
36 #ifdef _WIN32
37 typedef signed char int8_t;
38 typedef unsigned char uint8_t;
39 typedef signed short int16_t;
40 typedef unsigned short uint16_t;
41 typedef signed int int32_t;
42 typedef unsigned int uint32_t;
43 #if __GNUC__
44 typedef signed long long int64_t;
45 typedef unsigned long long uint64_t;
46 #else /* _MSC_VER || __BORLANDC__ */
47 typedef signed __int64 int64_t;
48 typedef unsigned __int64 uint64_t;
49 #endif
50 #ifdef _WIN64
51 #define ECB_PTRSIZE 8
52 typedef uint64_t uintptr_t;
53 typedef int64_t intptr_t;
54 #else
55 #define ECB_PTRSIZE 4
56 typedef uint32_t uintptr_t;
57 typedef int32_t intptr_t;
58 #endif
59 typedef intptr_t ptrdiff_t;
60 #else
61 #include <inttypes.h>
62 #if UINTMAX_MAX > 0xffffffffU
63 #define ECB_PTRSIZE 8
64 #else
65 #define ECB_PTRSIZE 4
66 #endif
67 #endif
68
69 /* many compilers define _GNUC_ to some versions but then only implement
70 * what their idiot authors think are the "more important" extensions,
71 * causing enormous grief in return for some better fake benchmark numbers.
72 * or so.
73 * we try to detect these and simply assume they are not gcc - if they have
74 * an issue with that they should have done it right in the first place.
75 */
76 #ifndef ECB_GCC_VERSION
77 #if !defined __GNUC_MINOR__ || defined __INTEL_COMPILER || defined __SUNPRO_C || defined __SUNPRO_CC || defined __llvm__ || defined __clang__
78 #define ECB_GCC_VERSION(major,minor) 0
79 #else
80 #define ECB_GCC_VERSION(major,minor) (__GNUC__ > (major) || (__GNUC__ == (major) && __GNUC_MINOR__ >= (minor)))
81 #endif
82 #endif
83
84 #define ECB_C (__STDC__+0) /* this assumes that __STDC__ is either empty or a number */
85 #define ECB_C99 (__STDC_VERSION__ >= 199901L)
86 #define ECB_C11 (__STDC_VERSION__ >= 201112L)
87 #define ECB_CPP (__cplusplus+0)
88 #define ECB_CPP98 (__cplusplus >= 199711L)
89 #define ECB_CPP11 (__cplusplus >= 201103L)
90
91 /*****************************************************************************/
92
93 /* ECB_NO_THREADS - ecb is not used by multiple threads, ever */
94 /* ECB_NO_SMP - ecb might be used in multiple threads, but only on a single cpu */
95
96 #if ECB_NO_THREADS
97 # define ECB_NO_SMP 1
98 #endif
99
100 #if ECB_NO_SMP
101 #define ECB_MEMORY_FENCE do { } while (0)
102 #endif
103
104 #ifndef ECB_MEMORY_FENCE
105 #if ECB_C11 && !defined __STDC_NO_ATOMICS__
106 /* we assume that these memory fences work on all variables/all memory accesses, */
107 /* not just C11 atomics and atomic accesses */
108 #include <stdatomic.h>
109 #if 0
110 #define ECB_MEMORY_FENCE atomic_thread_fence (memory_order_acq_rel)
111 #define ECB_MEMORY_FENCE_ACQUIRE atomic_thread_fence (memory_order_acquire)
112 #define ECB_MEMORY_FENCE_RELEASE atomic_thread_fence (memory_order_release)
113 #else
114 /* the above *should* be enough in my book, but after experiences with gcc-4.7 */
115 /* and clang, better play safe */
116 #define ECB_MEMORY_FENCE atomic_thread_fence (memory_order_seq_cst)
117 #endif
118 #endif
119 #endif
120
121 #ifndef ECB_MEMORY_FENCE
122 #if ECB_GCC_VERSION(2,5) || defined __INTEL_COMPILER || (__llvm__ && __GNUC__) || __SUNPRO_C >= 0x5110 || __SUNPRO_CC >= 0x5110
123 #if __i386 || __i386__
124 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("lock; orb $0, -1(%%esp)" : : : "memory")
125 #define ECB_MEMORY_FENCE_ACQUIRE ECB_MEMORY_FENCE /* non-lock xchg might be enough */
126 #define ECB_MEMORY_FENCE_RELEASE do { } while (0) /* unlikely to change in future cpus */
127 #elif __amd64 || __amd64__ || __x86_64 || __x86_64__
128 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("mfence" : : : "memory")
129 #define ECB_MEMORY_FENCE_ACQUIRE __asm__ __volatile__ ("lfence" : : : "memory")
130 #define ECB_MEMORY_FENCE_RELEASE __asm__ __volatile__ ("sfence") /* play safe - not needed in any current cpu */
131 #elif __powerpc__ || __ppc__ || __powerpc64__ || __ppc64__
132 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("sync" : : : "memory")
133 #elif defined __ARM_ARCH_6__ || defined __ARM_ARCH_6J__ \
134 || defined __ARM_ARCH_6K__ || defined __ARM_ARCH_6ZK__
135 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("mcr p15,0,%0,c7,c10,5" : : "r" (0) : "memory")
136 #elif defined __ARM_ARCH_7__ || defined __ARM_ARCH_7A__ \
137 || defined __ARM_ARCH_7M__ || defined __ARM_ARCH_7R__
138 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("dmb" : : : "memory")
139 #elif __sparc || __sparc__
140 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("membar #LoadStore | #LoadLoad | #StoreStore | #StoreLoad | " : : : "memory")
141 #define ECB_MEMORY_FENCE_ACQUIRE __asm__ __volatile__ ("membar #LoadStore | #LoadLoad" : : : "memory")
142 #define ECB_MEMORY_FENCE_RELEASE __asm__ __volatile__ ("membar #LoadStore | #StoreStore")
143 #elif defined __s390__ || defined __s390x__
144 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("bcr 15,0" : : : "memory")
145 #elif defined __mips__
146 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("sync" : : : "memory")
147 #elif defined __alpha__
148 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("mb" : : : "memory")
149 #endif
150 #endif
151 #endif
152
153 #ifndef ECB_MEMORY_FENCE
154 #if ECB_GCC_VERSION(4,7)
155 /* unsolved mystery: ACQ_REL should be enough, but doesn't generate any code */
156 /* which in turn actually breaks libev */
157 #define ECB_MEMORY_FENCE __atomic_thread_fence (__ATOMIC_SEQ_CST)
158 #elif defined __clang && __has_feature (cxx_atomic)
159 /* see above */
160 #define ECB_MEMORY_FENCE __c11_atomic_thread_fence (__ATOMIC_SEQ_CST)
161 #elif ECB_GCC_VERSION(4,4) || defined __INTEL_COMPILER || defined __clang__
162 #define ECB_MEMORY_FENCE __sync_synchronize ()
163 /*#define ECB_MEMORY_FENCE_ACQUIRE ({ char dummy = 0; __sync_lock_test_and_set (&dummy, 1); }) */
164 /*#define ECB_MEMORY_FENCE_RELEASE ({ char dummy = 1; __sync_lock_release (&dummy ); }) */
165 #elif _MSC_VER >= 1400 /* VC++ 2005 */
166 #pragma intrinsic(_ReadBarrier,_WriteBarrier,_ReadWriteBarrier)
167 #define ECB_MEMORY_FENCE _ReadWriteBarrier ()
168 #define ECB_MEMORY_FENCE_ACQUIRE _ReadWriteBarrier () /* according to msdn, _ReadBarrier is not a load fence */
169 #define ECB_MEMORY_FENCE_RELEASE _WriteBarrier ()
170 #elif defined _WIN32
171 #include <WinNT.h>
172 #define ECB_MEMORY_FENCE MemoryBarrier () /* actually just xchg on x86... scary */
173 #elif __SUNPRO_C >= 0x5110 || __SUNPRO_CC >= 0x5110
174 #include <mbarrier.h>
175 #define ECB_MEMORY_FENCE __machine_rw_barrier ()
176 #define ECB_MEMORY_FENCE_ACQUIRE __machine_r_barrier ()
177 #define ECB_MEMORY_FENCE_RELEASE __machine_w_barrier ()
178 #elif __xlC__
179 #define ECB_MEMORY_FENCE __sync ()
180 #endif
181 #endif
182
183 #ifndef ECB_MEMORY_FENCE
184 #if !ECB_AVOID_PTHREADS
185 /*
186 * if you get undefined symbol references to pthread_mutex_lock,
187 * or failure to find pthread.h, then you should implement
188 * the ECB_MEMORY_FENCE operations for your cpu/compiler
189 * OR provide pthread.h and link against the posix thread library
190 * of your system.
191 */
192 #include <pthread.h>
193 #define ECB_NEEDS_PTHREADS 1
194 #define ECB_MEMORY_FENCE_NEEDS_PTHREADS 1
195
196 static pthread_mutex_t ecb_mf_lock = PTHREAD_MUTEX_INITIALIZER;
197 #define ECB_MEMORY_FENCE do { pthread_mutex_lock (&ecb_mf_lock); pthread_mutex_unlock (&ecb_mf_lock); } while (0)
198 #endif
199 #endif
200
201 #if !defined ECB_MEMORY_FENCE_ACQUIRE && defined ECB_MEMORY_FENCE
202 #define ECB_MEMORY_FENCE_ACQUIRE ECB_MEMORY_FENCE
203 #endif
204
205 #if !defined ECB_MEMORY_FENCE_RELEASE && defined ECB_MEMORY_FENCE
206 #define ECB_MEMORY_FENCE_RELEASE ECB_MEMORY_FENCE
207 #endif
208
209 /*****************************************************************************/
210
211 #if __cplusplus
212 #define ecb_inline static inline
213 #elif ECB_GCC_VERSION(2,5)
214 #define ecb_inline static __inline__
215 #elif ECB_C99
216 #define ecb_inline static inline
217 #else
218 #define ecb_inline static
219 #endif
220
221 #if ECB_GCC_VERSION(3,3)
222 #define ecb_restrict __restrict__
223 #elif ECB_C99
224 #define ecb_restrict restrict
225 #else
226 #define ecb_restrict
227 #endif
228
229 typedef int ecb_bool;
230
231 #define ECB_CONCAT_(a, b) a ## b
232 #define ECB_CONCAT(a, b) ECB_CONCAT_(a, b)
233 #define ECB_STRINGIFY_(a) # a
234 #define ECB_STRINGIFY(a) ECB_STRINGIFY_(a)
235
236 #define ecb_function_ ecb_inline
237
238 #if ECB_GCC_VERSION(3,1)
239 #define ecb_attribute(attrlist) __attribute__(attrlist)
240 #define ecb_is_constant(expr) __builtin_constant_p (expr)
241 #define ecb_expect(expr,value) __builtin_expect ((expr),(value))
242 #define ecb_prefetch(addr,rw,locality) __builtin_prefetch (addr, rw, locality)
243 #else
244 #define ecb_attribute(attrlist)
245 #define ecb_is_constant(expr) 0
246 #define ecb_expect(expr,value) (expr)
247 #define ecb_prefetch(addr,rw,locality)
248 #endif
249
250 /* no emulation for ecb_decltype */
251 #if ECB_GCC_VERSION(4,5)
252 #define ecb_decltype(x) __decltype(x)
253 #elif ECB_GCC_VERSION(3,0)
254 #define ecb_decltype(x) __typeof(x)
255 #endif
256
257 #define ecb_noinline ecb_attribute ((__noinline__))
258 #define ecb_unused ecb_attribute ((__unused__))
259 #define ecb_const ecb_attribute ((__const__))
260 #define ecb_pure ecb_attribute ((__pure__))
261
262 #if ECB_C11
263 #define ecb_noreturn _Noreturn
264 #else
265 #define ecb_noreturn ecb_attribute ((__noreturn__))
266 #endif
267
268 #if ECB_GCC_VERSION(4,3)
269 #define ecb_artificial ecb_attribute ((__artificial__))
270 #define ecb_hot ecb_attribute ((__hot__))
271 #define ecb_cold ecb_attribute ((__cold__))
272 #else
273 #define ecb_artificial
274 #define ecb_hot
275 #define ecb_cold
276 #endif
277
278 /* put around conditional expressions if you are very sure that the */
279 /* expression is mostly true or mostly false. note that these return */
280 /* booleans, not the expression. */
281 #define ecb_expect_false(expr) ecb_expect (!!(expr), 0)
282 #define ecb_expect_true(expr) ecb_expect (!!(expr), 1)
283 /* for compatibility to the rest of the world */
284 #define ecb_likely(expr) ecb_expect_true (expr)
285 #define ecb_unlikely(expr) ecb_expect_false (expr)
286
287 /* count trailing zero bits and count # of one bits */
288 #if ECB_GCC_VERSION(3,4)
289 /* we assume int == 32 bit, long == 32 or 64 bit and long long == 64 bit */
290 #define ecb_ld32(x) (__builtin_clz (x) ^ 31)
291 #define ecb_ld64(x) (__builtin_clzll (x) ^ 63)
292 #define ecb_ctz32(x) __builtin_ctz (x)
293 #define ecb_ctz64(x) __builtin_ctzll (x)
294 #define ecb_popcount32(x) __builtin_popcount (x)
295 /* no popcountll */
296 #else
297 ecb_function_ int ecb_ctz32 (uint32_t x) ecb_const;
298 ecb_function_ int
299 ecb_ctz32 (uint32_t x)
300 {
301 int r = 0;
302
303 x &= ~x + 1; /* this isolates the lowest bit */
304
305 #if ECB_branchless_on_i386
306 r += !!(x & 0xaaaaaaaa) << 0;
307 r += !!(x & 0xcccccccc) << 1;
308 r += !!(x & 0xf0f0f0f0) << 2;
309 r += !!(x & 0xff00ff00) << 3;
310 r += !!(x & 0xffff0000) << 4;
311 #else
312 if (x & 0xaaaaaaaa) r += 1;
313 if (x & 0xcccccccc) r += 2;
314 if (x & 0xf0f0f0f0) r += 4;
315 if (x & 0xff00ff00) r += 8;
316 if (x & 0xffff0000) r += 16;
317 #endif
318
319 return r;
320 }
321
322 ecb_function_ int ecb_ctz64 (uint64_t x) ecb_const;
323 ecb_function_ int
324 ecb_ctz64 (uint64_t x)
325 {
326 int shift = x & 0xffffffffU ? 0 : 32;
327 return ecb_ctz32 (x >> shift) + shift;
328 }
329
330 ecb_function_ int ecb_popcount32 (uint32_t x) ecb_const;
331 ecb_function_ int
332 ecb_popcount32 (uint32_t x)
333 {
334 x -= (x >> 1) & 0x55555555;
335 x = ((x >> 2) & 0x33333333) + (x & 0x33333333);
336 x = ((x >> 4) + x) & 0x0f0f0f0f;
337 x *= 0x01010101;
338
339 return x >> 24;
340 }
341
342 ecb_function_ int ecb_ld32 (uint32_t x) ecb_const;
343 ecb_function_ int ecb_ld32 (uint32_t x)
344 {
345 int r = 0;
346
347 if (x >> 16) { x >>= 16; r += 16; }
348 if (x >> 8) { x >>= 8; r += 8; }
349 if (x >> 4) { x >>= 4; r += 4; }
350 if (x >> 2) { x >>= 2; r += 2; }
351 if (x >> 1) { r += 1; }
352
353 return r;
354 }
355
356 ecb_function_ int ecb_ld64 (uint64_t x) ecb_const;
357 ecb_function_ int ecb_ld64 (uint64_t x)
358 {
359 int r = 0;
360
361 if (x >> 32) { x >>= 32; r += 32; }
362
363 return r + ecb_ld32 (x);
364 }
365 #endif
366
367 ecb_function_ ecb_bool ecb_is_pot32 (uint32_t x) ecb_const;
368 ecb_function_ ecb_bool ecb_is_pot32 (uint32_t x) { return !(x & (x - 1)); }
369 ecb_function_ ecb_bool ecb_is_pot64 (uint64_t x) ecb_const;
370 ecb_function_ ecb_bool ecb_is_pot64 (uint64_t x) { return !(x & (x - 1)); }
371
372 ecb_function_ uint8_t ecb_bitrev8 (uint8_t x) ecb_const;
373 ecb_function_ uint8_t ecb_bitrev8 (uint8_t x)
374 {
375 return ( (x * 0x0802U & 0x22110U)
376 | (x * 0x8020U & 0x88440U)) * 0x10101U >> 16;
377 }
378
379 ecb_function_ uint16_t ecb_bitrev16 (uint16_t x) ecb_const;
380 ecb_function_ uint16_t ecb_bitrev16 (uint16_t x)
381 {
382 x = ((x >> 1) & 0x5555) | ((x & 0x5555) << 1);
383 x = ((x >> 2) & 0x3333) | ((x & 0x3333) << 2);
384 x = ((x >> 4) & 0x0f0f) | ((x & 0x0f0f) << 4);
385 x = ( x >> 8 ) | ( x << 8);
386
387 return x;
388 }
389
390 ecb_function_ uint32_t ecb_bitrev32 (uint32_t x) ecb_const;
391 ecb_function_ uint32_t ecb_bitrev32 (uint32_t x)
392 {
393 x = ((x >> 1) & 0x55555555) | ((x & 0x55555555) << 1);
394 x = ((x >> 2) & 0x33333333) | ((x & 0x33333333) << 2);
395 x = ((x >> 4) & 0x0f0f0f0f) | ((x & 0x0f0f0f0f) << 4);
396 x = ((x >> 8) & 0x00ff00ff) | ((x & 0x00ff00ff) << 8);
397 x = ( x >> 16 ) | ( x << 16);
398
399 return x;
400 }
401
402 /* popcount64 is only available on 64 bit cpus as gcc builtin */
403 /* so for this version we are lazy */
404 ecb_function_ int ecb_popcount64 (uint64_t x) ecb_const;
405 ecb_function_ int
406 ecb_popcount64 (uint64_t x)
407 {
408 return ecb_popcount32 (x) + ecb_popcount32 (x >> 32);
409 }
410
411 ecb_inline uint8_t ecb_rotl8 (uint8_t x, unsigned int count) ecb_const;
412 ecb_inline uint8_t ecb_rotr8 (uint8_t x, unsigned int count) ecb_const;
413 ecb_inline uint16_t ecb_rotl16 (uint16_t x, unsigned int count) ecb_const;
414 ecb_inline uint16_t ecb_rotr16 (uint16_t x, unsigned int count) ecb_const;
415 ecb_inline uint32_t ecb_rotl32 (uint32_t x, unsigned int count) ecb_const;
416 ecb_inline uint32_t ecb_rotr32 (uint32_t x, unsigned int count) ecb_const;
417 ecb_inline uint64_t ecb_rotl64 (uint64_t x, unsigned int count) ecb_const;
418 ecb_inline uint64_t ecb_rotr64 (uint64_t x, unsigned int count) ecb_const;
419
420 ecb_inline uint8_t ecb_rotl8 (uint8_t x, unsigned int count) { return (x >> ( 8 - count)) | (x << count); }
421 ecb_inline uint8_t ecb_rotr8 (uint8_t x, unsigned int count) { return (x << ( 8 - count)) | (x >> count); }
422 ecb_inline uint16_t ecb_rotl16 (uint16_t x, unsigned int count) { return (x >> (16 - count)) | (x << count); }
423 ecb_inline uint16_t ecb_rotr16 (uint16_t x, unsigned int count) { return (x << (16 - count)) | (x >> count); }
424 ecb_inline uint32_t ecb_rotl32 (uint32_t x, unsigned int count) { return (x >> (32 - count)) | (x << count); }
425 ecb_inline uint32_t ecb_rotr32 (uint32_t x, unsigned int count) { return (x << (32 - count)) | (x >> count); }
426 ecb_inline uint64_t ecb_rotl64 (uint64_t x, unsigned int count) { return (x >> (64 - count)) | (x << count); }
427 ecb_inline uint64_t ecb_rotr64 (uint64_t x, unsigned int count) { return (x << (64 - count)) | (x >> count); }
428
429 #if ECB_GCC_VERSION(4,3)
430 #define ecb_bswap16(x) (__builtin_bswap32 (x) >> 16)
431 #define ecb_bswap32(x) __builtin_bswap32 (x)
432 #define ecb_bswap64(x) __builtin_bswap64 (x)
433 #else
434 ecb_function_ uint16_t ecb_bswap16 (uint16_t x) ecb_const;
435 ecb_function_ uint16_t
436 ecb_bswap16 (uint16_t x)
437 {
438 return ecb_rotl16 (x, 8);
439 }
440
441 ecb_function_ uint32_t ecb_bswap32 (uint32_t x) ecb_const;
442 ecb_function_ uint32_t
443 ecb_bswap32 (uint32_t x)
444 {
445 return (((uint32_t)ecb_bswap16 (x)) << 16) | ecb_bswap16 (x >> 16);
446 }
447
448 ecb_function_ uint64_t ecb_bswap64 (uint64_t x) ecb_const;
449 ecb_function_ uint64_t
450 ecb_bswap64 (uint64_t x)
451 {
452 return (((uint64_t)ecb_bswap32 (x)) << 32) | ecb_bswap32 (x >> 32);
453 }
454 #endif
455
456 #if ECB_GCC_VERSION(4,5)
457 #define ecb_unreachable() __builtin_unreachable ()
458 #else
459 /* this seems to work fine, but gcc always emits a warning for it :/ */
460 ecb_inline void ecb_unreachable (void) ecb_noreturn;
461 ecb_inline void ecb_unreachable (void) { }
462 #endif
463
464 /* try to tell the compiler that some condition is definitely true */
465 #define ecb_assume(cond) do { if (!(cond)) ecb_unreachable (); } while (0)
466
467 ecb_inline unsigned char ecb_byteorder_helper (void) ecb_const;
468 ecb_inline unsigned char
469 ecb_byteorder_helper (void)
470 {
471 const uint32_t u = 0x11223344;
472 return *(unsigned char *)&u;
473 }
474
475 ecb_inline ecb_bool ecb_big_endian (void) ecb_const;
476 ecb_inline ecb_bool ecb_big_endian (void) { return ecb_byteorder_helper () == 0x11; }
477 ecb_inline ecb_bool ecb_little_endian (void) ecb_const;
478 ecb_inline ecb_bool ecb_little_endian (void) { return ecb_byteorder_helper () == 0x44; }
479
480 #if ECB_GCC_VERSION(3,0) || ECB_C99
481 #define ecb_mod(m,n) ((m) % (n) + ((m) % (n) < 0 ? (n) : 0))
482 #else
483 #define ecb_mod(m,n) ((m) < 0 ? ((n) - 1 - ((-1 - (m)) % (n))) : ((m) % (n)))
484 #endif
485
486 #if __cplusplus
487 template<typename T>
488 static inline T ecb_div_rd (T val, T div)
489 {
490 return val < 0 ? - ((-val + div - 1) / div) : (val ) / div;
491 }
492 template<typename T>
493 static inline T ecb_div_ru (T val, T div)
494 {
495 return val < 0 ? - ((-val ) / div) : (val + div - 1) / div;
496 }
497 #else
498 #define ecb_div_rd(val,div) ((val) < 0 ? - ((-(val) + (div) - 1) / (div)) : ((val) ) / (div))
499 #define ecb_div_ru(val,div) ((val) < 0 ? - ((-(val) ) / (div)) : ((val) + (div) - 1) / (div))
500 #endif
501
502 #if ecb_cplusplus_does_not_suck
503 /* does not work for local types (http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2657.htm) */
504 template<typename T, int N>
505 static inline int ecb_array_length (const T (&arr)[N])
506 {
507 return N;
508 }
509 #else
510 #define ecb_array_length(name) (sizeof (name) / sizeof (name [0]))
511 #endif
512
513 #endif
514