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Revision: 1.88
Committed: Mon May 28 08:40:25 2012 UTC (12 years ago) by root
Content type: text/plain
Branch: MAIN
Changes since 1.87: +5 -0 lines
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# User Rev Content
1 root 1.1 /*
2 root 1.17 * libecb - http://software.schmorp.de/pkg/libecb
3 root 1.1 *
4 root 1.72 * Copyright (©) 2009-2012 Marc Alexander Lehmann <libecb@schmorp.de>
5 root 1.7 * Copyright (©) 2011 Emanuele Giaquinta
6 root 1.1 * 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 root 1.87 /* 16 bits major, 16 bits minor */
34     #define ECB_VERSION 0x00010001
35    
36 root 1.44 #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 root 1.51 #else /* _MSC_VER || __BORLANDC__ */
47 root 1.44 typedef signed __int64 int64_t;
48     typedef unsigned __int64 uint64_t;
49     #endif
50 root 1.87 #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 root 1.44 #else
60     #include <inttypes.h>
61 root 1.87 #if UINTMAX_MAX > 0xffffffffU
62     #define ECB_PTRSIZE 8
63     #else
64     #define ECB_PTRSIZE 4
65     #endif
66 root 1.44 #endif
67 root 1.6
68 root 1.12 /* many compilers define _GNUC_ to some versions but then only implement
69     * what their idiot authors think are the "more important" extensions,
70 sf-exg 1.59 * causing enormous grief in return for some better fake benchmark numbers.
71 root 1.18 * or so.
72 root 1.12 * 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 root 1.14 #ifndef ECB_GCC_VERSION
76 root 1.85 #if !defined __GNUC_MINOR__ || defined __INTEL_COMPILER || defined __SUNPRO_C || defined __SUNPRO_CC || defined __llvm__ || defined __clang__
77 root 1.37 #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 root 1.12 #endif
82 root 1.1
83 root 1.52 /*****************************************************************************/
84    
85 root 1.58 /* ECB_NO_THREADS - ecb is not used by multiple threads, ever */
86     /* ECB_NO_SMP - ecb might be used in multiple threads, but only on a single cpu */
87    
88 root 1.79 #if ECB_NO_THREADS
89     # define ECB_NO_SMP 1
90     #endif
91    
92 root 1.58 #if ECB_NO_THREADS || ECB_NO_SMP
93 root 1.64 #define ECB_MEMORY_FENCE do { } while (0)
94 root 1.58 #endif
95    
96 root 1.52 #ifndef ECB_MEMORY_FENCE
97 root 1.85 #if ECB_GCC_VERSION(2,5) || defined __INTEL_COMPILER || (__llvm__ && __GNUC__) || __SUNPRO_C >= 0x5110 || __SUNPRO_CC >= 0x5110
98 root 1.73 #if __i386 || __i386__
99 root 1.54 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("lock; orb $0, -1(%%esp)" : : : "memory")
100 root 1.57 #define ECB_MEMORY_FENCE_ACQUIRE ECB_MEMORY_FENCE /* non-lock xchg might be enough */
101     #define ECB_MEMORY_FENCE_RELEASE do { } while (0) /* unlikely to change in future cpus */
102 root 1.73 #elif __amd64 || __amd64__ || __x86_64 || __x86_64__
103 root 1.52 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("mfence" : : : "memory")
104     #define ECB_MEMORY_FENCE_ACQUIRE __asm__ __volatile__ ("lfence" : : : "memory")
105 root 1.57 #define ECB_MEMORY_FENCE_RELEASE __asm__ __volatile__ ("sfence") /* play safe - not needed in any current cpu */
106 root 1.63 #elif __powerpc__ || __ppc__ || __powerpc64__ || __ppc64__
107     #define ECB_MEMORY_FENCE __asm__ __volatile__ ("sync" : : : "memory")
108 root 1.85 #elif defined __ARM_ARCH_6__ || defined __ARM_ARCH_6J__ \
109     || defined __ARM_ARCH_6K__ || defined __ARM_ARCH_6ZK__
110 root 1.84 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("mcr p15,0,%0,c7,c10,5" : : "r" (0) : "memory")
111 root 1.85 #elif defined __ARM_ARCH_7__ || defined __ARM_ARCH_7A__ \
112     || defined __ARM_ARCH_7M__ || defined __ARM_ARCH_7R__
113 root 1.65 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("dmb" : : : "memory")
114 root 1.73 #elif __sparc || __sparc__
115 root 1.74 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("membar #LoadStore | #LoadLoad | #StoreStore | #StoreLoad | " : : : "memory")
116 root 1.77 #define ECB_MEMORY_FENCE_ACQUIRE __asm__ __volatile__ ("membar #LoadStore | #LoadLoad" : : : "memory")
117 root 1.74 #define ECB_MEMORY_FENCE_RELEASE __asm__ __volatile__ ("membar #LoadStore | #StoreStore")
118 root 1.85 #elif defined __s390__ || defined __s390x__
119 root 1.77 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("bcr 15,0" : : : "memory")
120 root 1.85 #elif defined __mips__
121 root 1.80 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("sync" : : : "memory")
122 root 1.86 #elif defined __alpha__
123     #define ECB_MEMORY_FENCE __asm__ __volatile__ ("mb" : : : "memory")
124 root 1.52 #endif
125     #endif
126     #endif
127    
128     #ifndef ECB_MEMORY_FENCE
129 root 1.85 #if ECB_GCC_VERSION(4,4) || defined __INTEL_COMPILER || defined __clang__
130 root 1.52 #define ECB_MEMORY_FENCE __sync_synchronize ()
131 root 1.62 /*#define ECB_MEMORY_FENCE_ACQUIRE ({ char dummy = 0; __sync_lock_test_and_set (&dummy, 1); }) */
132     /*#define ECB_MEMORY_FENCE_RELEASE ({ char dummy = 1; __sync_lock_release (&dummy ); }) */
133 root 1.57 #elif _MSC_VER >= 1400 /* VC++ 2005 */
134     #pragma intrinsic(_ReadBarrier,_WriteBarrier,_ReadWriteBarrier)
135     #define ECB_MEMORY_FENCE _ReadWriteBarrier ()
136     #define ECB_MEMORY_FENCE_ACQUIRE _ReadWriteBarrier () /* according to msdn, _ReadBarrier is not a load fence */
137     #define ECB_MEMORY_FENCE_RELEASE _WriteBarrier ()
138 root 1.85 #elif defined _WIN32
139 root 1.55 #include <WinNT.h>
140 root 1.57 #define ECB_MEMORY_FENCE MemoryBarrier () /* actually just xchg on x86... scary */
141 root 1.72 #elif __SUNPRO_C >= 0x5110 || __SUNPRO_CC >= 0x5110
142     #include <mbarrier.h>
143     #define ECB_MEMORY_FENCE __machine_rw_barrier ()
144     #define ECB_MEMORY_FENCE_ACQUIRE __machine_r_barrier ()
145     #define ECB_MEMORY_FENCE_RELEASE __machine_w_barrier ()
146 root 1.82 #elif __xlC__
147 root 1.83 #define ECB_MEMORY_FENCE __sync ()
148 root 1.52 #endif
149     #endif
150    
151 root 1.53 #ifndef ECB_MEMORY_FENCE
152 root 1.62 #if !ECB_AVOID_PTHREADS
153     /*
154     * if you get undefined symbol references to pthread_mutex_lock,
155     * or failure to find pthread.h, then you should implement
156     * the ECB_MEMORY_FENCE operations for your cpu/compiler
157     * OR provide pthread.h and link against the posix thread library
158     * of your system.
159     */
160     #include <pthread.h>
161     #define ECB_NEEDS_PTHREADS 1
162     #define ECB_MEMORY_FENCE_NEEDS_PTHREADS 1
163 root 1.52
164 root 1.62 static pthread_mutex_t ecb_mf_lock = PTHREAD_MUTEX_INITIALIZER;
165     #define ECB_MEMORY_FENCE do { pthread_mutex_lock (&ecb_mf_lock); pthread_mutex_unlock (&ecb_mf_lock); } while (0)
166     #endif
167     #endif
168    
169 root 1.85 #if !defined ECB_MEMORY_FENCE_ACQUIRE && defined ECB_MEMORY_FENCE
170 root 1.52 #define ECB_MEMORY_FENCE_ACQUIRE ECB_MEMORY_FENCE
171 root 1.62 #endif
172    
173 root 1.85 #if !defined ECB_MEMORY_FENCE_RELEASE && defined ECB_MEMORY_FENCE
174 root 1.52 #define ECB_MEMORY_FENCE_RELEASE ECB_MEMORY_FENCE
175     #endif
176    
177     /*****************************************************************************/
178    
179 root 1.39 #define ECB_C99 (__STDC_VERSION__ >= 199901L)
180    
181     #if __cplusplus
182 root 1.46 #define ecb_inline static inline
183 root 1.38 #elif ECB_GCC_VERSION(2,5)
184 root 1.46 #define ecb_inline static __inline__
185 root 1.39 #elif ECB_C99
186 root 1.46 #define ecb_inline static inline
187 root 1.29 #else
188 root 1.46 #define ecb_inline static
189 root 1.38 #endif
190    
191     #if ECB_GCC_VERSION(3,3)
192     #define ecb_restrict __restrict__
193 root 1.39 #elif ECB_C99
194 root 1.38 #define ecb_restrict restrict
195     #else
196     #define ecb_restrict
197 root 1.4 #endif
198    
199 root 1.38 typedef int ecb_bool;
200    
201 root 1.8 #define ECB_CONCAT_(a, b) a ## b
202     #define ECB_CONCAT(a, b) ECB_CONCAT_(a, b)
203     #define ECB_STRINGIFY_(a) # a
204     #define ECB_STRINGIFY(a) ECB_STRINGIFY_(a)
205    
206 root 1.46 #define ecb_function_ ecb_inline
207 root 1.3
208 root 1.1 #if ECB_GCC_VERSION(3,1)
209 root 1.37 #define ecb_attribute(attrlist) __attribute__(attrlist)
210     #define ecb_is_constant(expr) __builtin_constant_p (expr)
211     #define ecb_expect(expr,value) __builtin_expect ((expr),(value))
212     #define ecb_prefetch(addr,rw,locality) __builtin_prefetch (addr, rw, locality)
213     #else
214     #define ecb_attribute(attrlist)
215     #define ecb_is_constant(expr) 0
216     #define ecb_expect(expr,value) (expr)
217     #define ecb_prefetch(addr,rw,locality)
218 root 1.1 #endif
219    
220 root 1.2 /* no emulation for ecb_decltype */
221 root 1.1 #if ECB_GCC_VERSION(4,5)
222 root 1.37 #define ecb_decltype(x) __decltype(x)
223 root 1.1 #elif ECB_GCC_VERSION(3,0)
224 root 1.39 #define ecb_decltype(x) __typeof(x)
225 root 1.1 #endif
226    
227 root 1.24 #define ecb_noinline ecb_attribute ((__noinline__))
228     #define ecb_noreturn ecb_attribute ((__noreturn__))
229     #define ecb_unused ecb_attribute ((__unused__))
230     #define ecb_const ecb_attribute ((__const__))
231     #define ecb_pure ecb_attribute ((__pure__))
232 root 1.35
233     #if ECB_GCC_VERSION(4,3)
234 root 1.39 #define ecb_artificial ecb_attribute ((__artificial__))
235     #define ecb_hot ecb_attribute ((__hot__))
236     #define ecb_cold ecb_attribute ((__cold__))
237 root 1.35 #else
238     #define ecb_artificial
239     #define ecb_hot
240     #define ecb_cold
241     #endif
242 root 1.1
243 root 1.39 /* put around conditional expressions if you are very sure that the */
244     /* expression is mostly true or mostly false. note that these return */
245     /* booleans, not the expression. */
246 root 1.33 #define ecb_expect_false(expr) ecb_expect (!!(expr), 0)
247     #define ecb_expect_true(expr) ecb_expect (!!(expr), 1)
248 root 1.36 /* for compatibility to the rest of the world */
249 root 1.33 #define ecb_likely(expr) ecb_expect_true (expr)
250     #define ecb_unlikely(expr) ecb_expect_false (expr)
251 root 1.1
252 root 1.3 /* count trailing zero bits and count # of one bits */
253 root 1.1 #if ECB_GCC_VERSION(3,4)
254 root 1.49 /* we assume int == 32 bit, long == 32 or 64 bit and long long == 64 bit */
255     #define ecb_ld32(x) (__builtin_clz (x) ^ 31)
256     #define ecb_ld64(x) (__builtin_clzll (x) ^ 63)
257 root 1.35 #define ecb_ctz32(x) __builtin_ctz (x)
258 root 1.49 #define ecb_ctz64(x) __builtin_ctzll (x)
259 root 1.35 #define ecb_popcount32(x) __builtin_popcount (x)
260 root 1.49 /* no popcountll */
261 root 1.1 #else
262 root 1.39 ecb_function_ int ecb_ctz32 (uint32_t x) ecb_const;
263     ecb_function_ int
264 root 1.35 ecb_ctz32 (uint32_t x)
265     {
266     int r = 0;
267    
268 root 1.48 x &= ~x + 1; /* this isolates the lowest bit */
269 root 1.35
270 root 1.50 #if ECB_branchless_on_i386
271     r += !!(x & 0xaaaaaaaa) << 0;
272     r += !!(x & 0xcccccccc) << 1;
273     r += !!(x & 0xf0f0f0f0) << 2;
274     r += !!(x & 0xff00ff00) << 3;
275     r += !!(x & 0xffff0000) << 4;
276     #else
277 root 1.35 if (x & 0xaaaaaaaa) r += 1;
278     if (x & 0xcccccccc) r += 2;
279     if (x & 0xf0f0f0f0) r += 4;
280     if (x & 0xff00ff00) r += 8;
281     if (x & 0xffff0000) r += 16;
282 root 1.50 #endif
283 root 1.35
284     return r;
285     }
286    
287 root 1.49 ecb_function_ int ecb_ctz64 (uint64_t x) ecb_const;
288     ecb_function_ int
289     ecb_ctz64 (uint64_t x)
290     {
291     int shift = x & 0xffffffffU ? 0 : 32;
292 root 1.50 return ecb_ctz32 (x >> shift) + shift;
293 root 1.49 }
294    
295 root 1.39 ecb_function_ int ecb_popcount32 (uint32_t x) ecb_const;
296     ecb_function_ int
297 root 1.35 ecb_popcount32 (uint32_t x)
298     {
299     x -= (x >> 1) & 0x55555555;
300     x = ((x >> 2) & 0x33333333) + (x & 0x33333333);
301     x = ((x >> 4) + x) & 0x0f0f0f0f;
302     x *= 0x01010101;
303 root 1.1
304 root 1.35 return x >> 24;
305     }
306 root 1.49
307     ecb_function_ int ecb_ld32 (uint32_t x) ecb_const;
308     ecb_function_ int ecb_ld32 (uint32_t x)
309     {
310 root 1.50 int r = 0;
311 root 1.49
312 root 1.50 if (x >> 16) { x >>= 16; r += 16; }
313     if (x >> 8) { x >>= 8; r += 8; }
314     if (x >> 4) { x >>= 4; r += 4; }
315     if (x >> 2) { x >>= 2; r += 2; }
316     if (x >> 1) { r += 1; }
317 root 1.49
318     return r;
319     }
320    
321     ecb_function_ int ecb_ld64 (uint64_t x) ecb_const;
322     ecb_function_ int ecb_ld64 (uint64_t x)
323     {
324 root 1.50 int r = 0;
325 root 1.49
326 root 1.50 if (x >> 32) { x >>= 32; r += 32; }
327 root 1.49
328 root 1.50 return r + ecb_ld32 (x);
329 root 1.49 }
330 root 1.1 #endif
331    
332 root 1.88 ecb_function_ ecb_bool ecb_is_pot32 (uint32_t x) ecb_const;
333     ecb_function_ ecb_bool ecb_is_pot32 (uint32_t x) { return !(x & (x - 1)); }
334     ecb_function_ ecb_bool ecb_is_pot64 (uint64_t x) ecb_const;
335     ecb_function_ ecb_bool ecb_is_pot64 (uint64_t x) { return !(x & (x - 1)); }
336    
337 root 1.71 ecb_function_ uint8_t ecb_bitrev8 (uint8_t x) ecb_const;
338 root 1.70 ecb_function_ uint8_t ecb_bitrev8 (uint8_t x)
339     {
340     return ( (x * 0x0802U & 0x22110U)
341     | (x * 0x8020U & 0x88440U)) * 0x10101U >> 16;
342     }
343    
344 root 1.71 ecb_function_ uint16_t ecb_bitrev16 (uint16_t x) ecb_const;
345 root 1.70 ecb_function_ uint16_t ecb_bitrev16 (uint16_t x)
346     {
347     x = ((x >> 1) & 0x5555) | ((x & 0x5555) << 1);
348     x = ((x >> 2) & 0x3333) | ((x & 0x3333) << 2);
349     x = ((x >> 4) & 0x0f0f) | ((x & 0x0f0f) << 4);
350     x = ( x >> 8 ) | ( x << 8);
351    
352     return x;
353     }
354    
355 root 1.71 ecb_function_ uint32_t ecb_bitrev32 (uint32_t x) ecb_const;
356 root 1.70 ecb_function_ uint32_t ecb_bitrev32 (uint32_t x)
357     {
358     x = ((x >> 1) & 0x55555555) | ((x & 0x55555555) << 1);
359     x = ((x >> 2) & 0x33333333) | ((x & 0x33333333) << 2);
360     x = ((x >> 4) & 0x0f0f0f0f) | ((x & 0x0f0f0f0f) << 4);
361     x = ((x >> 8) & 0x00ff00ff) | ((x & 0x00ff00ff) << 8);
362     x = ( x >> 16 ) | ( x << 16);
363    
364     return x;
365     }
366    
367 root 1.49 /* popcount64 is only available on 64 bit cpus as gcc builtin */
368     /* so for this version we are lazy */
369     ecb_function_ int ecb_popcount64 (uint64_t x) ecb_const;
370     ecb_function_ int
371     ecb_popcount64 (uint64_t x)
372     {
373     return ecb_popcount32 (x) + ecb_popcount32 (x >> 32);
374     }
375    
376 root 1.50 ecb_inline uint8_t ecb_rotl8 (uint8_t x, unsigned int count) ecb_const;
377     ecb_inline uint8_t ecb_rotr8 (uint8_t x, unsigned int count) ecb_const;
378     ecb_inline uint16_t ecb_rotl16 (uint16_t x, unsigned int count) ecb_const;
379     ecb_inline uint16_t ecb_rotr16 (uint16_t x, unsigned int count) ecb_const;
380     ecb_inline uint32_t ecb_rotl32 (uint32_t x, unsigned int count) ecb_const;
381     ecb_inline uint32_t ecb_rotr32 (uint32_t x, unsigned int count) ecb_const;
382     ecb_inline uint64_t ecb_rotl64 (uint64_t x, unsigned int count) ecb_const;
383     ecb_inline uint64_t ecb_rotr64 (uint64_t x, unsigned int count) ecb_const;
384    
385     ecb_inline uint8_t ecb_rotl8 (uint8_t x, unsigned int count) { return (x >> ( 8 - count)) | (x << count); }
386     ecb_inline uint8_t ecb_rotr8 (uint8_t x, unsigned int count) { return (x << ( 8 - count)) | (x >> count); }
387     ecb_inline uint16_t ecb_rotl16 (uint16_t x, unsigned int count) { return (x >> (16 - count)) | (x << count); }
388     ecb_inline uint16_t ecb_rotr16 (uint16_t x, unsigned int count) { return (x << (16 - count)) | (x >> count); }
389     ecb_inline uint32_t ecb_rotl32 (uint32_t x, unsigned int count) { return (x >> (32 - count)) | (x << count); }
390     ecb_inline uint32_t ecb_rotr32 (uint32_t x, unsigned int count) { return (x << (32 - count)) | (x >> count); }
391     ecb_inline uint64_t ecb_rotl64 (uint64_t x, unsigned int count) { return (x >> (64 - count)) | (x << count); }
392     ecb_inline uint64_t ecb_rotr64 (uint64_t x, unsigned int count) { return (x << (64 - count)) | (x >> count); }
393    
394 root 1.13 #if ECB_GCC_VERSION(4,3)
395 root 1.49 #define ecb_bswap16(x) (__builtin_bswap32 (x) >> 16)
396     #define ecb_bswap32(x) __builtin_bswap32 (x)
397     #define ecb_bswap64(x) __builtin_bswap64 (x)
398 root 1.13 #else
399 root 1.50 ecb_function_ uint16_t ecb_bswap16 (uint16_t x) ecb_const;
400     ecb_function_ uint16_t
401     ecb_bswap16 (uint16_t x)
402 root 1.49 {
403 root 1.50 return ecb_rotl16 (x, 8);
404 root 1.49 }
405    
406 root 1.39 ecb_function_ uint32_t ecb_bswap32 (uint32_t x) ecb_const;
407     ecb_function_ uint32_t
408 root 1.35 ecb_bswap32 (uint32_t x)
409     {
410 root 1.50 return (((uint32_t)ecb_bswap16 (x)) << 16) | ecb_bswap16 (x >> 16);
411 root 1.35 }
412    
413 root 1.49 ecb_function_ uint64_t ecb_bswap64 (uint64_t x) ecb_const;
414     ecb_function_ uint64_t
415     ecb_bswap64 (uint64_t x)
416 root 1.35 {
417 root 1.50 return (((uint64_t)ecb_bswap32 (x)) << 32) | ecb_bswap32 (x >> 32);
418 root 1.35 }
419 root 1.13 #endif
420    
421     #if ECB_GCC_VERSION(4,5)
422 root 1.35 #define ecb_unreachable() __builtin_unreachable ()
423 root 1.13 #else
424 root 1.35 /* this seems to work fine, but gcc always emits a warning for it :/ */
425 root 1.75 ecb_inline void ecb_unreachable (void) ecb_noreturn;
426     ecb_inline void ecb_unreachable (void) { }
427 root 1.13 #endif
428    
429 root 1.41 /* try to tell the compiler that some condition is definitely true */
430     #define ecb_assume(cond) do { if (!(cond)) ecb_unreachable (); } while (0)
431    
432 root 1.76 ecb_inline unsigned char ecb_byteorder_helper (void) ecb_const;
433     ecb_inline unsigned char
434 root 1.23 ecb_byteorder_helper (void)
435 root 1.3 {
436     const uint32_t u = 0x11223344;
437     return *(unsigned char *)&u;
438     }
439    
440 root 1.76 ecb_inline ecb_bool ecb_big_endian (void) ecb_const;
441     ecb_inline ecb_bool ecb_big_endian (void) { return ecb_byteorder_helper () == 0x11; }
442     ecb_inline ecb_bool ecb_little_endian (void) ecb_const;
443     ecb_inline ecb_bool ecb_little_endian (void) { return ecb_byteorder_helper () == 0x44; }
444 root 1.3
445 root 1.39 #if ECB_GCC_VERSION(3,0) || ECB_C99
446 root 1.35 #define ecb_mod(m,n) ((m) % (n) + ((m) % (n) < 0 ? (n) : 0))
447 root 1.31 #else
448 root 1.35 #define ecb_mod(m,n) ((m) < 0 ? ((n) - 1 - ((-1 - (m)) % (n))) : ((m) % (n)))
449 root 1.31 #endif
450 root 1.21
451 sf-exg 1.68 #if __cplusplus
452     template<typename T>
453     static inline T ecb_div_rd (T val, T div)
454     {
455     return val < 0 ? - ((-val + div - 1) / div) : (val ) / div;
456     }
457     template<typename T>
458     static inline T ecb_div_ru (T val, T div)
459     {
460     return val < 0 ? - ((-val ) / div) : (val + div - 1) / div;
461     }
462     #else
463     #define ecb_div_rd(val,div) ((val) < 0 ? - ((-(val) + (div) - 1) / (div)) : ((val) ) / (div))
464     #define ecb_div_ru(val,div) ((val) < 0 ? - ((-(val) ) / (div)) : ((val) + (div) - 1) / (div))
465     #endif
466 sf-exg 1.67
467 root 1.5 #if ecb_cplusplus_does_not_suck
468 root 1.40 /* does not work for local types (http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2657.htm) */
469 root 1.35 template<typename T, int N>
470     static inline int ecb_array_length (const T (&arr)[N])
471     {
472     return N;
473     }
474 root 1.5 #else
475 root 1.35 #define ecb_array_length(name) (sizeof (name) / sizeof (name [0]))
476 root 1.5 #endif
477    
478 root 1.1 #endif
479