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Revision: 1.111
Committed: Wed Jul 25 09:24:57 2012 UTC (11 years, 10 months ago) by sf-exg
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Branch: MAIN
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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 0x00010002
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 #else
60 #include <inttypes.h>
61 #if UINTMAX_MAX > 0xffffffffU
62 #define ECB_PTRSIZE 8
63 #else
64 #define ECB_PTRSIZE 4
65 #endif
66 #endif
67
68 /* many compilers define _GNUC_ to some versions but then only implement
69 * what their idiot authors think are the "more important" extensions,
70 * causing enormous grief in return for some better fake benchmark numbers.
71 * or so.
72 * we try to detect these and simply assume they are not gcc - if they have
73 * an issue with that they should have done it right in the first place.
74 */
75 #ifndef ECB_GCC_VERSION
76 #if !defined __GNUC_MINOR__ || defined __INTEL_COMPILER || defined __SUNPRO_C || defined __SUNPRO_CC || defined __llvm__ || defined __clang__
77 #define ECB_GCC_VERSION(major,minor) 0
78 #else
79 #define ECB_GCC_VERSION(major,minor) (__GNUC__ > (major) || (__GNUC__ == (major) && __GNUC_MINOR__ >= (minor)))
80 #endif
81 #endif
82
83 #define ECB_C (__STDC__+0) /* this assumes that __STDC__ is either empty or a number */
84 #define ECB_C99 (__STDC_VERSION__ >= 199901L)
85 #define ECB_C11 (__STDC_VERSION__ >= 201112L)
86 #define ECB_CPP (__cplusplus+0)
87 #define ECB_CPP11 (__cplusplus >= 201103L)
88
89 #if ECB_CPP
90 #define ECB_EXTERN_C extern "C"
91 #define ECB_EXTERN_C_BEG ECB_EXTERN_C {
92 #define ECB_EXTERN_C_END }
93 #else
94 #define ECB_EXTERN_C extern
95 #define ECB_EXTERN_C_BEG
96 #define ECB_EXTERN_C_END
97 #endif
98
99 /*****************************************************************************/
100
101 /* ECB_NO_THREADS - ecb is not used by multiple threads, ever */
102 /* ECB_NO_SMP - ecb might be used in multiple threads, but only on a single cpu */
103
104 #if ECB_NO_THREADS
105 #define ECB_NO_SMP 1
106 #endif
107
108 #if ECB_NO_SMP
109 #define ECB_MEMORY_FENCE do { } while (0)
110 #endif
111
112 #ifndef ECB_MEMORY_FENCE
113 #if ECB_GCC_VERSION(2,5) || defined __INTEL_COMPILER || (__llvm__ && __GNUC__) || __SUNPRO_C >= 0x5110 || __SUNPRO_CC >= 0x5110
114 #if __i386 || __i386__
115 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("lock; orb $0, -1(%%esp)" : : : "memory")
116 #define ECB_MEMORY_FENCE_ACQUIRE __asm__ __volatile__ ("" : : : "memory")
117 #define ECB_MEMORY_FENCE_RELEASE __asm__ __volatile__ ("")
118 #elif __amd64 || __amd64__ || __x86_64 || __x86_64__
119 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("mfence" : : : "memory")
120 #define ECB_MEMORY_FENCE_ACQUIRE __asm__ __volatile__ ("" : : : "memory")
121 #define ECB_MEMORY_FENCE_RELEASE __asm__ __volatile__ ("")
122 #elif __powerpc__ || __ppc__ || __powerpc64__ || __ppc64__
123 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("sync" : : : "memory")
124 #elif defined __ARM_ARCH_6__ || defined __ARM_ARCH_6J__ \
125 || defined __ARM_ARCH_6K__ || defined __ARM_ARCH_6ZK__
126 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("mcr p15,0,%0,c7,c10,5" : : "r" (0) : "memory")
127 #elif defined __ARM_ARCH_7__ || defined __ARM_ARCH_7A__ \
128 || defined __ARM_ARCH_7M__ || defined __ARM_ARCH_7R__
129 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("dmb" : : : "memory")
130 #elif __sparc || __sparc__
131 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("membar #LoadStore | #LoadLoad | #StoreStore | #StoreLoad" : : : "memory")
132 #define ECB_MEMORY_FENCE_ACQUIRE __asm__ __volatile__ ("membar #LoadStore | #LoadLoad" : : : "memory")
133 #define ECB_MEMORY_FENCE_RELEASE __asm__ __volatile__ ("membar #LoadStore | #StoreStore")
134 #elif defined __s390__ || defined __s390x__
135 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("bcr 15,0" : : : "memory")
136 #elif defined __mips__
137 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("sync" : : : "memory")
138 #elif defined __alpha__
139 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("mb" : : : "memory")
140 #elif defined __hppa__
141 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("" : : : "memory")
142 #define ECB_MEMORY_FENCE_RELEASE __asm__ __volatile__ ("")
143 #elif defined __ia64__
144 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("mf" : : : "memory")
145 #endif
146 #endif
147 #endif
148
149 #ifndef ECB_MEMORY_FENCE
150 #if ECB_GCC_VERSION(4,7)
151 /* see comment below (stdatomic.h) about the C11 memory model. */
152 #define ECB_MEMORY_FENCE __atomic_thread_fence (__ATOMIC_SEQ_CST)
153
154 /* The __has_feature syntax from clang is so misdesigned that we cannot use it
155 * without risking compile time errors with other compilers. We *could*
156 * define our own ecb_clang_has_feature, but I just can't be bothered to work
157 * around * this shit time and again.
158 * #elif defined __clang && __has_feature (cxx_atomic)
159 * // see comment below (stdatomic.h) about the C11 memory model.
160 * #define ECB_MEMORY_FENCE __c11_atomic_thread_fence (__ATOMIC_SEQ_CST)
161 */
162
163 #elif ECB_GCC_VERSION(4,4) || defined __INTEL_COMPILER || defined __clang__
164 #define ECB_MEMORY_FENCE __sync_synchronize ()
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_C11 && !defined __STDC_NO_ATOMICS__
185 /* we assume that these memory fences work on all variables/all memory accesses, */
186 /* not just C11 atomics and atomic accesses */
187 #include <stdatomic.h>
188 /* Unfortunately, neither gcc 4.7 nor clang 3.1 generate any instructions for */
189 /* any fence other than seq_cst, which isn't very efficient for us. */
190 /* Why that is, we don't know - either the C11 memory model is quite useless */
191 /* for most usages, or gcc and clang have a bug */
192 /* I *currently* lean towards the latter, and inefficiently implement */
193 /* all three of ecb's fences as a seq_cst fence */
194 #define ECB_MEMORY_FENCE atomic_thread_fence (memory_order_seq_cst)
195 #endif
196 #endif
197
198 #ifndef ECB_MEMORY_FENCE
199 #if !ECB_AVOID_PTHREADS
200 /*
201 * if you get undefined symbol references to pthread_mutex_lock,
202 * or failure to find pthread.h, then you should implement
203 * the ECB_MEMORY_FENCE operations for your cpu/compiler
204 * OR provide pthread.h and link against the posix thread library
205 * of your system.
206 */
207 #include <pthread.h>
208 #define ECB_NEEDS_PTHREADS 1
209 #define ECB_MEMORY_FENCE_NEEDS_PTHREADS 1
210
211 static pthread_mutex_t ecb_mf_lock = PTHREAD_MUTEX_INITIALIZER;
212 #define ECB_MEMORY_FENCE do { pthread_mutex_lock (&ecb_mf_lock); pthread_mutex_unlock (&ecb_mf_lock); } while (0)
213 #endif
214 #endif
215
216 #if !defined ECB_MEMORY_FENCE_ACQUIRE && defined ECB_MEMORY_FENCE
217 #define ECB_MEMORY_FENCE_ACQUIRE ECB_MEMORY_FENCE
218 #endif
219
220 #if !defined ECB_MEMORY_FENCE_RELEASE && defined ECB_MEMORY_FENCE
221 #define ECB_MEMORY_FENCE_RELEASE ECB_MEMORY_FENCE
222 #endif
223
224 /*****************************************************************************/
225
226 #if __cplusplus
227 #define ecb_inline static inline
228 #elif ECB_GCC_VERSION(2,5)
229 #define ecb_inline static __inline__
230 #elif ECB_C99
231 #define ecb_inline static inline
232 #else
233 #define ecb_inline static
234 #endif
235
236 #if ECB_GCC_VERSION(3,3)
237 #define ecb_restrict __restrict__
238 #elif ECB_C99
239 #define ecb_restrict restrict
240 #else
241 #define ecb_restrict
242 #endif
243
244 typedef int ecb_bool;
245
246 #define ECB_CONCAT_(a, b) a ## b
247 #define ECB_CONCAT(a, b) ECB_CONCAT_(a, b)
248 #define ECB_STRINGIFY_(a) # a
249 #define ECB_STRINGIFY(a) ECB_STRINGIFY_(a)
250
251 #define ecb_function_ ecb_inline
252
253 #if ECB_GCC_VERSION(3,1)
254 #define ecb_attribute(attrlist) __attribute__(attrlist)
255 #define ecb_is_constant(expr) __builtin_constant_p (expr)
256 #define ecb_expect(expr,value) __builtin_expect ((expr),(value))
257 #define ecb_prefetch(addr,rw,locality) __builtin_prefetch (addr, rw, locality)
258 #else
259 #define ecb_attribute(attrlist)
260 #define ecb_is_constant(expr) 0
261 #define ecb_expect(expr,value) (expr)
262 #define ecb_prefetch(addr,rw,locality)
263 #endif
264
265 /* no emulation for ecb_decltype */
266 #if ECB_GCC_VERSION(4,5)
267 #define ecb_decltype(x) __decltype(x)
268 #elif ECB_GCC_VERSION(3,0)
269 #define ecb_decltype(x) __typeof(x)
270 #endif
271
272 #define ecb_noinline ecb_attribute ((__noinline__))
273 #define ecb_unused ecb_attribute ((__unused__))
274 #define ecb_const ecb_attribute ((__const__))
275 #define ecb_pure ecb_attribute ((__pure__))
276
277 #if ECB_C11
278 #define ecb_noreturn _Noreturn
279 #else
280 #define ecb_noreturn ecb_attribute ((__noreturn__))
281 #endif
282
283 #if ECB_GCC_VERSION(4,3)
284 #define ecb_artificial ecb_attribute ((__artificial__))
285 #define ecb_hot ecb_attribute ((__hot__))
286 #define ecb_cold ecb_attribute ((__cold__))
287 #else
288 #define ecb_artificial
289 #define ecb_hot
290 #define ecb_cold
291 #endif
292
293 /* put around conditional expressions if you are very sure that the */
294 /* expression is mostly true or mostly false. note that these return */
295 /* booleans, not the expression. */
296 #define ecb_expect_false(expr) ecb_expect (!!(expr), 0)
297 #define ecb_expect_true(expr) ecb_expect (!!(expr), 1)
298 /* for compatibility to the rest of the world */
299 #define ecb_likely(expr) ecb_expect_true (expr)
300 #define ecb_unlikely(expr) ecb_expect_false (expr)
301
302 /* count trailing zero bits and count # of one bits */
303 #if ECB_GCC_VERSION(3,4)
304 /* we assume int == 32 bit, long == 32 or 64 bit and long long == 64 bit */
305 #define ecb_ld32(x) (__builtin_clz (x) ^ 31)
306 #define ecb_ld64(x) (__builtin_clzll (x) ^ 63)
307 #define ecb_ctz32(x) __builtin_ctz (x)
308 #define ecb_ctz64(x) __builtin_ctzll (x)
309 #define ecb_popcount32(x) __builtin_popcount (x)
310 /* no popcountll */
311 #else
312 ecb_function_ int ecb_ctz32 (uint32_t x) ecb_const;
313 ecb_function_ int
314 ecb_ctz32 (uint32_t x)
315 {
316 int r = 0;
317
318 x &= ~x + 1; /* this isolates the lowest bit */
319
320 #if ECB_branchless_on_i386
321 r += !!(x & 0xaaaaaaaa) << 0;
322 r += !!(x & 0xcccccccc) << 1;
323 r += !!(x & 0xf0f0f0f0) << 2;
324 r += !!(x & 0xff00ff00) << 3;
325 r += !!(x & 0xffff0000) << 4;
326 #else
327 if (x & 0xaaaaaaaa) r += 1;
328 if (x & 0xcccccccc) r += 2;
329 if (x & 0xf0f0f0f0) r += 4;
330 if (x & 0xff00ff00) r += 8;
331 if (x & 0xffff0000) r += 16;
332 #endif
333
334 return r;
335 }
336
337 ecb_function_ int ecb_ctz64 (uint64_t x) ecb_const;
338 ecb_function_ int
339 ecb_ctz64 (uint64_t x)
340 {
341 int shift = x & 0xffffffffU ? 0 : 32;
342 return ecb_ctz32 (x >> shift) + shift;
343 }
344
345 ecb_function_ int ecb_popcount32 (uint32_t x) ecb_const;
346 ecb_function_ int
347 ecb_popcount32 (uint32_t x)
348 {
349 x -= (x >> 1) & 0x55555555;
350 x = ((x >> 2) & 0x33333333) + (x & 0x33333333);
351 x = ((x >> 4) + x) & 0x0f0f0f0f;
352 x *= 0x01010101;
353
354 return x >> 24;
355 }
356
357 ecb_function_ int ecb_ld32 (uint32_t x) ecb_const;
358 ecb_function_ int ecb_ld32 (uint32_t x)
359 {
360 int r = 0;
361
362 if (x >> 16) { x >>= 16; r += 16; }
363 if (x >> 8) { x >>= 8; r += 8; }
364 if (x >> 4) { x >>= 4; r += 4; }
365 if (x >> 2) { x >>= 2; r += 2; }
366 if (x >> 1) { r += 1; }
367
368 return r;
369 }
370
371 ecb_function_ int ecb_ld64 (uint64_t x) ecb_const;
372 ecb_function_ int ecb_ld64 (uint64_t x)
373 {
374 int r = 0;
375
376 if (x >> 32) { x >>= 32; r += 32; }
377
378 return r + ecb_ld32 (x);
379 }
380 #endif
381
382 ecb_function_ ecb_bool ecb_is_pot32 (uint32_t x) ecb_const;
383 ecb_function_ ecb_bool ecb_is_pot32 (uint32_t x) { return !(x & (x - 1)); }
384 ecb_function_ ecb_bool ecb_is_pot64 (uint64_t x) ecb_const;
385 ecb_function_ ecb_bool ecb_is_pot64 (uint64_t x) { return !(x & (x - 1)); }
386
387 ecb_function_ uint8_t ecb_bitrev8 (uint8_t x) ecb_const;
388 ecb_function_ uint8_t ecb_bitrev8 (uint8_t x)
389 {
390 return ( (x * 0x0802U & 0x22110U)
391 | (x * 0x8020U & 0x88440U)) * 0x10101U >> 16;
392 }
393
394 ecb_function_ uint16_t ecb_bitrev16 (uint16_t x) ecb_const;
395 ecb_function_ uint16_t ecb_bitrev16 (uint16_t x)
396 {
397 x = ((x >> 1) & 0x5555) | ((x & 0x5555) << 1);
398 x = ((x >> 2) & 0x3333) | ((x & 0x3333) << 2);
399 x = ((x >> 4) & 0x0f0f) | ((x & 0x0f0f) << 4);
400 x = ( x >> 8 ) | ( x << 8);
401
402 return x;
403 }
404
405 ecb_function_ uint32_t ecb_bitrev32 (uint32_t x) ecb_const;
406 ecb_function_ uint32_t ecb_bitrev32 (uint32_t x)
407 {
408 x = ((x >> 1) & 0x55555555) | ((x & 0x55555555) << 1);
409 x = ((x >> 2) & 0x33333333) | ((x & 0x33333333) << 2);
410 x = ((x >> 4) & 0x0f0f0f0f) | ((x & 0x0f0f0f0f) << 4);
411 x = ((x >> 8) & 0x00ff00ff) | ((x & 0x00ff00ff) << 8);
412 x = ( x >> 16 ) | ( x << 16);
413
414 return x;
415 }
416
417 /* popcount64 is only available on 64 bit cpus as gcc builtin */
418 /* so for this version we are lazy */
419 ecb_function_ int ecb_popcount64 (uint64_t x) ecb_const;
420 ecb_function_ int
421 ecb_popcount64 (uint64_t x)
422 {
423 return ecb_popcount32 (x) + ecb_popcount32 (x >> 32);
424 }
425
426 ecb_inline uint8_t ecb_rotl8 (uint8_t x, unsigned int count) ecb_const;
427 ecb_inline uint8_t ecb_rotr8 (uint8_t x, unsigned int count) ecb_const;
428 ecb_inline uint16_t ecb_rotl16 (uint16_t x, unsigned int count) ecb_const;
429 ecb_inline uint16_t ecb_rotr16 (uint16_t x, unsigned int count) ecb_const;
430 ecb_inline uint32_t ecb_rotl32 (uint32_t x, unsigned int count) ecb_const;
431 ecb_inline uint32_t ecb_rotr32 (uint32_t x, unsigned int count) ecb_const;
432 ecb_inline uint64_t ecb_rotl64 (uint64_t x, unsigned int count) ecb_const;
433 ecb_inline uint64_t ecb_rotr64 (uint64_t x, unsigned int count) ecb_const;
434
435 ecb_inline uint8_t ecb_rotl8 (uint8_t x, unsigned int count) { return (x >> ( 8 - count)) | (x << count); }
436 ecb_inline uint8_t ecb_rotr8 (uint8_t x, unsigned int count) { return (x << ( 8 - count)) | (x >> count); }
437 ecb_inline uint16_t ecb_rotl16 (uint16_t x, unsigned int count) { return (x >> (16 - count)) | (x << count); }
438 ecb_inline uint16_t ecb_rotr16 (uint16_t x, unsigned int count) { return (x << (16 - count)) | (x >> count); }
439 ecb_inline uint32_t ecb_rotl32 (uint32_t x, unsigned int count) { return (x >> (32 - count)) | (x << count); }
440 ecb_inline uint32_t ecb_rotr32 (uint32_t x, unsigned int count) { return (x << (32 - count)) | (x >> count); }
441 ecb_inline uint64_t ecb_rotl64 (uint64_t x, unsigned int count) { return (x >> (64 - count)) | (x << count); }
442 ecb_inline uint64_t ecb_rotr64 (uint64_t x, unsigned int count) { return (x << (64 - count)) | (x >> count); }
443
444 #if ECB_GCC_VERSION(4,3)
445 #define ecb_bswap16(x) (__builtin_bswap32 (x) >> 16)
446 #define ecb_bswap32(x) __builtin_bswap32 (x)
447 #define ecb_bswap64(x) __builtin_bswap64 (x)
448 #else
449 ecb_function_ uint16_t ecb_bswap16 (uint16_t x) ecb_const;
450 ecb_function_ uint16_t
451 ecb_bswap16 (uint16_t x)
452 {
453 return ecb_rotl16 (x, 8);
454 }
455
456 ecb_function_ uint32_t ecb_bswap32 (uint32_t x) ecb_const;
457 ecb_function_ uint32_t
458 ecb_bswap32 (uint32_t x)
459 {
460 return (((uint32_t)ecb_bswap16 (x)) << 16) | ecb_bswap16 (x >> 16);
461 }
462
463 ecb_function_ uint64_t ecb_bswap64 (uint64_t x) ecb_const;
464 ecb_function_ uint64_t
465 ecb_bswap64 (uint64_t x)
466 {
467 return (((uint64_t)ecb_bswap32 (x)) << 32) | ecb_bswap32 (x >> 32);
468 }
469 #endif
470
471 #if ECB_GCC_VERSION(4,5)
472 #define ecb_unreachable() __builtin_unreachable ()
473 #else
474 /* this seems to work fine, but gcc always emits a warning for it :/ */
475 ecb_inline void ecb_unreachable (void) ecb_noreturn;
476 ecb_inline void ecb_unreachable (void) { }
477 #endif
478
479 /* try to tell the compiler that some condition is definitely true */
480 #define ecb_assume(cond) if (!(cond)) ecb_unreachable (); else 0
481
482 ecb_inline unsigned char ecb_byteorder_helper (void) ecb_const;
483 ecb_inline unsigned char
484 ecb_byteorder_helper (void)
485 {
486 /* the union code still generates code under pressure in gcc, */
487 /* but less than using pointers, and always seems to */
488 /* successfully return a constant. */
489 /* the reason why we have this horrible preprocessor mess */
490 /* is to avoid it in all cases, at least on common architectures */
491 /* or when using a recent enough gcc version (>= 4.6) */
492 #if __i386 || __i386__ || _M_X86 || __amd64 || __amd64__ || _M_X64
493 return 0x44;
494 #elif __BYTE_ORDER__ && __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
495 return 0x44;
496 #elif __BYTE_ORDER__ && __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
497 retrurn 0x11;
498 #else
499 union
500 {
501 uint32_t i;
502 uint8_t c;
503 } u = { 0x11223344 };
504 return u.c;
505 #endif
506 }
507
508 ecb_inline ecb_bool ecb_big_endian (void) ecb_const;
509 ecb_inline ecb_bool ecb_big_endian (void) { return ecb_byteorder_helper () == 0x11; }
510 ecb_inline ecb_bool ecb_little_endian (void) ecb_const;
511 ecb_inline ecb_bool ecb_little_endian (void) { return ecb_byteorder_helper () == 0x44; }
512
513 #if ECB_GCC_VERSION(3,0) || ECB_C99
514 #define ecb_mod(m,n) ((m) % (n) + ((m) % (n) < 0 ? (n) : 0))
515 #else
516 #define ecb_mod(m,n) ((m) < 0 ? ((n) - 1 - ((-1 - (m)) % (n))) : ((m) % (n)))
517 #endif
518
519 #if __cplusplus
520 template<typename T>
521 static inline T ecb_div_rd (T val, T div)
522 {
523 return val < 0 ? - ((-val + div - 1) / div) : (val ) / div;
524 }
525 template<typename T>
526 static inline T ecb_div_ru (T val, T div)
527 {
528 return val < 0 ? - ((-val ) / div) : (val + div - 1) / div;
529 }
530 #else
531 #define ecb_div_rd(val,div) ((val) < 0 ? - ((-(val) + (div) - 1) / (div)) : ((val) ) / (div))
532 #define ecb_div_ru(val,div) ((val) < 0 ? - ((-(val) ) / (div)) : ((val) + (div) - 1) / (div))
533 #endif
534
535 #if ecb_cplusplus_does_not_suck
536 /* does not work for local types (http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2657.htm) */
537 template<typename T, int N>
538 static inline int ecb_array_length (const T (&arr)[N])
539 {
540 return N;
541 }
542 #else
543 #define ecb_array_length(name) (sizeof (name) / sizeof (name [0]))
544 #endif
545
546 /*******************************************************************************/
547 /* floating point stuff, can be disabled by defining ECB_NO_LIBM */
548
549 /* basically, everything uses "ieee pure-endian" floating point numbers */
550 /* the only noteworthy exception is ancient armle, which uses order 43218765 */
551 #if 0 \
552 || __i386 || __i386__ \
553 || __amd64 || __amd64__ || __x86_64 || __x86_64__ \
554 || __powerpc__ || __ppc__ || __powerpc64__ || __ppc64__ \
555 || defined __arm__ && defined __ARM_EABI__ \
556 || defined __s390__ || defined __s390x__ \
557 || defined __mips__ \
558 || defined __alpha__ \
559 || defined __hppa__ \
560 || defined __ia64__ \
561 || defined _M_IX86 || defined _M_AMD64 || defined _M_IA64
562 #define ECB_STDFP 1
563 #include <string.h> /* for memcpy */
564 #else
565 #define ECB_STDFP 0
566 #include <math.h> /* for frexp*, ldexp* */
567 #endif
568
569 #ifndef ECB_NO_LIBM
570
571 /* convert a float to ieee single/binary32 */
572 ecb_function_ uint32_t ecb_float_to_binary32 (float x) ecb_const;
573 ecb_function_ uint32_t
574 ecb_float_to_binary32 (float x)
575 {
576 uint32_t r;
577
578 #if ECB_STDFP
579 memcpy (&r, &x, 4);
580 #else
581 /* slow emulation, works for anything but -0 */
582 uint32_t m;
583 int e;
584
585 if (x == 0e0f ) return 0x00000000U;
586 if (x > +3.40282346638528860e+38f) return 0x7f800000U;
587 if (x < -3.40282346638528860e+38f) return 0xff800000U;
588 if (x != x ) return 0x7fbfffffU;
589
590 m = frexpf (x, &e) * 0x1000000U;
591
592 r = m & 0x80000000U;
593
594 if (r)
595 m = -m;
596
597 if (e <= -126)
598 {
599 m &= 0xffffffU;
600 m >>= (-125 - e);
601 e = -126;
602 }
603
604 r |= (e + 126) << 23;
605 r |= m & 0x7fffffU;
606 #endif
607
608 return r;
609 }
610
611 /* converts an ieee single/binary32 to a float */
612 ecb_function_ float ecb_binary32_to_float (uint32_t x) ecb_const;
613 ecb_function_ float
614 ecb_binary32_to_float (uint32_t x)
615 {
616 float r;
617
618 #if ECB_STDFP
619 memcpy (&r, &x, 4);
620 #else
621 /* emulation, only works for normals and subnormals and +0 */
622 int neg = x >> 31;
623 int e = (x >> 23) & 0xffU;
624
625 x &= 0x7fffffU;
626
627 if (e)
628 x |= 0x800000U;
629 else
630 e = 1;
631
632 /* we distrust ldexpf a bit and do the 2**-24 scaling by an extra multiply */
633 r = ldexpf (x * (0.5f / 0x800000U), e - 126);
634
635 r = neg ? -r : r;
636 #endif
637
638 return r;
639 }
640
641 /* convert a double to ieee double/binary64 */
642 ecb_function_ uint64_t ecb_double_to_binary64 (double x) ecb_const;
643 ecb_function_ uint64_t
644 ecb_double_to_binary64 (double x)
645 {
646 uint64_t r;
647
648 #if ECB_STDFP
649 memcpy (&r, &x, 8);
650 #else
651 /* slow emulation, works for anything but -0 */
652 uint64_t m;
653 int e;
654
655 if (x == 0e0 ) return 0x0000000000000000U;
656 if (x > +1.79769313486231470e+308) return 0x7ff0000000000000U;
657 if (x < -1.79769313486231470e+308) return 0xfff0000000000000U;
658 if (x != x ) return 0X7ff7ffffffffffffU;
659
660 m = frexp (x, &e) * 0x20000000000000U;
661
662 r = m & 0x8000000000000000;;
663
664 if (r)
665 m = -m;
666
667 if (e <= -1022)
668 {
669 m &= 0x1fffffffffffffU;
670 m >>= (-1021 - e);
671 e = -1022;
672 }
673
674 r |= ((uint64_t)(e + 1022)) << 52;
675 r |= m & 0xfffffffffffffU;
676 #endif
677
678 return r;
679 }
680
681 /* converts an ieee double/binary64 to a double */
682 ecb_function_ double ecb_binary64_to_double (uint64_t x) ecb_const;
683 ecb_function_ double
684 ecb_binary64_to_double (uint64_t x)
685 {
686 double r;
687
688 #if ECB_STDFP
689 memcpy (&r, &x, 8);
690 #else
691 /* emulation, only works for normals and subnormals and +0 */
692 int neg = x >> 63;
693 int e = (x >> 52) & 0x7ffU;
694
695 x &= 0xfffffffffffffU;
696
697 if (e)
698 x |= 0x10000000000000U;
699 else
700 e = 1;
701
702 /* we distrust ldexp a bit and do the 2**-53 scaling by an extra multiply */
703 r = ldexp (x * (0.5 / 0x10000000000000U), e - 1022);
704
705 r = neg ? -r : r;
706 #endif
707
708 return r;
709 }
710
711 #endif
712
713 #endif
714