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Revision: 1.14
Committed: Sun Jun 17 17:07:25 2012 UTC (11 years, 11 months ago) by root
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Branch: MAIN
Changes since 1.13: +21 -3 lines
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# User Rev Content
1 root 1.1 /*
2     * libecb - http://software.schmorp.de/pkg/libecb
3     *
4 root 1.11 * Copyright (©) 2009-2012 Marc Alexander Lehmann <libecb@schmorp.de>
5 root 1.1 * 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 root 1.12 /* 16 bits major, 16 bits minor */
34     #define ECB_VERSION 0x00010001
35    
36 root 1.2 #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 1.3 #else /* _MSC_VER || __BORLANDC__ */
47 root 1.2 typedef signed __int64 int64_t;
48     typedef unsigned __int64 uint64_t;
49     #endif
50 root 1.12 #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 root 1.2 #else
61     #include <inttypes.h>
62 root 1.12 #if UINTMAX_MAX > 0xffffffffU
63     #define ECB_PTRSIZE 8
64     #else
65     #define ECB_PTRSIZE 4
66     #endif
67 root 1.2 #endif
68 root 1.1
69     /* many compilers define _GNUC_ to some versions but then only implement
70     * what their idiot authors think are the "more important" extensions,
71 root 1.8 * causing enormous grief in return for some better fake benchmark numbers.
72 root 1.1 * 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 root 1.11 #if !defined __GNUC_MINOR__ || defined __INTEL_COMPILER || defined __SUNPRO_C || defined __SUNPRO_CC || defined __llvm__ || defined __clang__
78 root 1.2 #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 root 1.1 #endif
83    
84 root 1.13 #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_CPP11 (__cplusplus >= 201103L)
89    
90 root 1.4 /*****************************************************************************/
91    
92 root 1.8 /* ECB_NO_THREADS - ecb is not used by multiple threads, ever */
93     /* ECB_NO_SMP - ecb might be used in multiple threads, but only on a single cpu */
94    
95 root 1.11 #if ECB_NO_THREADS
96 root 1.13 #define ECB_NO_SMP 1
97 root 1.11 #endif
98    
99 root 1.13 #if ECB_NO_SMP
100 root 1.8 #define ECB_MEMORY_FENCE do { } while (0)
101     #endif
102    
103 root 1.4 #ifndef ECB_MEMORY_FENCE
104 root 1.11 #if ECB_GCC_VERSION(2,5) || defined __INTEL_COMPILER || (__llvm__ && __GNUC__) || __SUNPRO_C >= 0x5110 || __SUNPRO_CC >= 0x5110
105     #if __i386 || __i386__
106 root 1.5 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("lock; orb $0, -1(%%esp)" : : : "memory")
107 root 1.13 #define ECB_MEMORY_FENCE_ACQUIRE __asm__ __volatile__ ("" : : : "memory")
108     #define ECB_MEMORY_FENCE_RELEASE __asm__ __volatile__ ("")
109 root 1.11 #elif __amd64 || __amd64__ || __x86_64 || __x86_64__
110 root 1.13 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("mfence" : : : "memory")
111     #define ECB_MEMORY_FENCE_ACQUIRE __asm__ __volatile__ ("" : : : "memory")
112     #define ECB_MEMORY_FENCE_RELEASE __asm__ __volatile__ ("")
113 root 1.8 #elif __powerpc__ || __ppc__ || __powerpc64__ || __ppc64__
114 root 1.13 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("sync" : : : "memory")
115 root 1.11 #elif defined __ARM_ARCH_6__ || defined __ARM_ARCH_6J__ \
116     || defined __ARM_ARCH_6K__ || defined __ARM_ARCH_6ZK__
117     #define ECB_MEMORY_FENCE __asm__ __volatile__ ("mcr p15,0,%0,c7,c10,5" : : "r" (0) : "memory")
118     #elif defined __ARM_ARCH_7__ || defined __ARM_ARCH_7A__ \
119 root 1.13 || defined __ARM_ARCH_7M__ || defined __ARM_ARCH_7R__
120     #define ECB_MEMORY_FENCE __asm__ __volatile__ ("dmb" : : : "memory")
121 root 1.11 #elif __sparc || __sparc__
122 root 1.13 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("membar #LoadStore | #LoadLoad | #StoreStore | #StoreLoad" : : : "memory")
123     #define ECB_MEMORY_FENCE_ACQUIRE __asm__ __volatile__ ("membar #LoadStore | #LoadLoad" : : : "memory")
124     #define ECB_MEMORY_FENCE_RELEASE __asm__ __volatile__ ("membar #LoadStore | #StoreStore")
125 root 1.11 #elif defined __s390__ || defined __s390x__
126     #define ECB_MEMORY_FENCE __asm__ __volatile__ ("bcr 15,0" : : : "memory")
127     #elif defined __mips__
128 root 1.13 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("sync" : : : "memory")
129 root 1.11 #elif defined __alpha__
130 root 1.13 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("mb" : : : "memory")
131     #elif defined __hppa__
132     #define ECB_MEMORY_FENCE __asm__ __volatile__ ("" : : : "memory")
133     #define ECB_MEMORY_FENCE_RELEASE __asm__ __volatile__ ("")
134     #elif defined __ia64__
135     #define ECB_MEMORY_FENCE __asm__ __volatile__ ("mf" : : : "memory")
136 root 1.4 #endif
137     #endif
138     #endif
139    
140     #ifndef ECB_MEMORY_FENCE
141 root 1.13 #if ECB_GCC_VERSION(4,7)
142     /* see comment below (stdatomic.h) about the C11 memory model. */
143     #define ECB_MEMORY_FENCE __atomic_thread_fence (__ATOMIC_SEQ_CST)
144     #elif defined __clang && __has_feature (cxx_atomic)
145     /* see comment below (stdatomic.h) about the C11 memory model. */
146     #define ECB_MEMORY_FENCE __c11_atomic_thread_fence (__ATOMIC_SEQ_CST)
147     #elif ECB_GCC_VERSION(4,4) || defined __INTEL_COMPILER || defined __clang__
148 root 1.4 #define ECB_MEMORY_FENCE __sync_synchronize ()
149 root 1.7 #elif _MSC_VER >= 1400 /* VC++ 2005 */
150     #pragma intrinsic(_ReadBarrier,_WriteBarrier,_ReadWriteBarrier)
151     #define ECB_MEMORY_FENCE _ReadWriteBarrier ()
152     #define ECB_MEMORY_FENCE_ACQUIRE _ReadWriteBarrier () /* according to msdn, _ReadBarrier is not a load fence */
153     #define ECB_MEMORY_FENCE_RELEASE _WriteBarrier ()
154 root 1.11 #elif defined _WIN32
155 root 1.6 #include <WinNT.h>
156 root 1.7 #define ECB_MEMORY_FENCE MemoryBarrier () /* actually just xchg on x86... scary */
157 root 1.11 #elif __SUNPRO_C >= 0x5110 || __SUNPRO_CC >= 0x5110
158     #include <mbarrier.h>
159     #define ECB_MEMORY_FENCE __machine_rw_barrier ()
160     #define ECB_MEMORY_FENCE_ACQUIRE __machine_r_barrier ()
161     #define ECB_MEMORY_FENCE_RELEASE __machine_w_barrier ()
162     #elif __xlC__
163     #define ECB_MEMORY_FENCE __sync ()
164 root 1.4 #endif
165     #endif
166    
167     #ifndef ECB_MEMORY_FENCE
168 root 1.13 #if ECB_C11 && !defined __STDC_NO_ATOMICS__
169     /* we assume that these memory fences work on all variables/all memory accesses, */
170     /* not just C11 atomics and atomic accesses */
171     #include <stdatomic.h>
172     /* Unfortunately, neither gcc 4.7 nor clang 3.1 generate any instructions for */
173     /* any fence other than seq_cst, which isn't very efficient for us. */
174     /* Why that is, we don't know - either the C11 memory model is quite useless */
175     /* for most usages, or gcc and clang have a bug */
176     /* I *currently* lean towards the latter, and inefficiently implement */
177     /* all three of ecb's fences as a seq_cst fence */
178     #define ECB_MEMORY_FENCE atomic_thread_fence (memory_order_seq_cst)
179     #endif
180     #endif
181    
182     #ifndef ECB_MEMORY_FENCE
183 root 1.8 #if !ECB_AVOID_PTHREADS
184     /*
185     * if you get undefined symbol references to pthread_mutex_lock,
186     * or failure to find pthread.h, then you should implement
187     * the ECB_MEMORY_FENCE operations for your cpu/compiler
188     * OR provide pthread.h and link against the posix thread library
189     * of your system.
190     */
191     #include <pthread.h>
192     #define ECB_NEEDS_PTHREADS 1
193     #define ECB_MEMORY_FENCE_NEEDS_PTHREADS 1
194    
195     static pthread_mutex_t ecb_mf_lock = PTHREAD_MUTEX_INITIALIZER;
196     #define ECB_MEMORY_FENCE do { pthread_mutex_lock (&ecb_mf_lock); pthread_mutex_unlock (&ecb_mf_lock); } while (0)
197     #endif
198     #endif
199 root 1.4
200 root 1.11 #if !defined ECB_MEMORY_FENCE_ACQUIRE && defined ECB_MEMORY_FENCE
201 root 1.4 #define ECB_MEMORY_FENCE_ACQUIRE ECB_MEMORY_FENCE
202 root 1.8 #endif
203    
204 root 1.11 #if !defined ECB_MEMORY_FENCE_RELEASE && defined ECB_MEMORY_FENCE
205 root 1.4 #define ECB_MEMORY_FENCE_RELEASE ECB_MEMORY_FENCE
206     #endif
207    
208     /*****************************************************************************/
209    
210 root 1.2 #if __cplusplus
211     #define ecb_inline static inline
212     #elif ECB_GCC_VERSION(2,5)
213     #define ecb_inline static __inline__
214     #elif ECB_C99
215     #define ecb_inline static inline
216     #else
217     #define ecb_inline static
218     #endif
219    
220     #if ECB_GCC_VERSION(3,3)
221     #define ecb_restrict __restrict__
222     #elif ECB_C99
223     #define ecb_restrict restrict
224 root 1.1 #else
225 root 1.2 #define ecb_restrict
226 root 1.1 #endif
227    
228 root 1.2 typedef int ecb_bool;
229    
230 root 1.1 #define ECB_CONCAT_(a, b) a ## b
231     #define ECB_CONCAT(a, b) ECB_CONCAT_(a, b)
232     #define ECB_STRINGIFY_(a) # a
233     #define ECB_STRINGIFY(a) ECB_STRINGIFY_(a)
234    
235 root 1.2 #define ecb_function_ ecb_inline
236 root 1.1
237     #if ECB_GCC_VERSION(3,1)
238 root 1.2 #define ecb_attribute(attrlist) __attribute__(attrlist)
239     #define ecb_is_constant(expr) __builtin_constant_p (expr)
240     #define ecb_expect(expr,value) __builtin_expect ((expr),(value))
241     #define ecb_prefetch(addr,rw,locality) __builtin_prefetch (addr, rw, locality)
242     #else
243     #define ecb_attribute(attrlist)
244     #define ecb_is_constant(expr) 0
245     #define ecb_expect(expr,value) (expr)
246     #define ecb_prefetch(addr,rw,locality)
247 root 1.1 #endif
248    
249     /* no emulation for ecb_decltype */
250     #if ECB_GCC_VERSION(4,5)
251 root 1.2 #define ecb_decltype(x) __decltype(x)
252 root 1.1 #elif ECB_GCC_VERSION(3,0)
253 root 1.2 #define ecb_decltype(x) __typeof(x)
254 root 1.1 #endif
255    
256     #define ecb_noinline ecb_attribute ((__noinline__))
257     #define ecb_unused ecb_attribute ((__unused__))
258     #define ecb_const ecb_attribute ((__const__))
259     #define ecb_pure ecb_attribute ((__pure__))
260    
261 root 1.13 #if ECB_C11
262     #define ecb_noreturn _Noreturn
263     #else
264     #define ecb_noreturn ecb_attribute ((__noreturn__))
265     #endif
266    
267 root 1.2 #if ECB_GCC_VERSION(4,3)
268     #define ecb_artificial ecb_attribute ((__artificial__))
269     #define ecb_hot ecb_attribute ((__hot__))
270     #define ecb_cold ecb_attribute ((__cold__))
271     #else
272     #define ecb_artificial
273     #define ecb_hot
274     #define ecb_cold
275     #endif
276    
277     /* put around conditional expressions if you are very sure that the */
278     /* expression is mostly true or mostly false. note that these return */
279     /* booleans, not the expression. */
280 root 1.1 #define ecb_expect_false(expr) ecb_expect (!!(expr), 0)
281     #define ecb_expect_true(expr) ecb_expect (!!(expr), 1)
282 root 1.2 /* for compatibility to the rest of the world */
283 root 1.1 #define ecb_likely(expr) ecb_expect_true (expr)
284     #define ecb_unlikely(expr) ecb_expect_false (expr)
285    
286     /* count trailing zero bits and count # of one bits */
287     #if ECB_GCC_VERSION(3,4)
288 root 1.2 /* we assume int == 32 bit, long == 32 or 64 bit and long long == 64 bit */
289     #define ecb_ld32(x) (__builtin_clz (x) ^ 31)
290     #define ecb_ld64(x) (__builtin_clzll (x) ^ 63)
291     #define ecb_ctz32(x) __builtin_ctz (x)
292     #define ecb_ctz64(x) __builtin_ctzll (x)
293     #define ecb_popcount32(x) __builtin_popcount (x)
294     /* no popcountll */
295 root 1.1 #else
296 root 1.2 ecb_function_ int ecb_ctz32 (uint32_t x) ecb_const;
297     ecb_function_ int
298     ecb_ctz32 (uint32_t x)
299     {
300     int r = 0;
301    
302     x &= ~x + 1; /* this isolates the lowest bit */
303    
304 root 1.3 #if ECB_branchless_on_i386
305     r += !!(x & 0xaaaaaaaa) << 0;
306     r += !!(x & 0xcccccccc) << 1;
307     r += !!(x & 0xf0f0f0f0) << 2;
308     r += !!(x & 0xff00ff00) << 3;
309     r += !!(x & 0xffff0000) << 4;
310     #else
311 root 1.2 if (x & 0xaaaaaaaa) r += 1;
312     if (x & 0xcccccccc) r += 2;
313     if (x & 0xf0f0f0f0) r += 4;
314     if (x & 0xff00ff00) r += 8;
315     if (x & 0xffff0000) r += 16;
316 root 1.3 #endif
317 root 1.2
318     return r;
319     }
320    
321     ecb_function_ int ecb_ctz64 (uint64_t x) ecb_const;
322     ecb_function_ int
323     ecb_ctz64 (uint64_t x)
324     {
325     int shift = x & 0xffffffffU ? 0 : 32;
326 root 1.3 return ecb_ctz32 (x >> shift) + shift;
327 root 1.2 }
328    
329     ecb_function_ int ecb_popcount32 (uint32_t x) ecb_const;
330     ecb_function_ int
331     ecb_popcount32 (uint32_t x)
332     {
333     x -= (x >> 1) & 0x55555555;
334     x = ((x >> 2) & 0x33333333) + (x & 0x33333333);
335     x = ((x >> 4) + x) & 0x0f0f0f0f;
336     x *= 0x01010101;
337    
338     return x >> 24;
339     }
340    
341     ecb_function_ int ecb_ld32 (uint32_t x) ecb_const;
342     ecb_function_ int ecb_ld32 (uint32_t x)
343     {
344 root 1.3 int r = 0;
345 root 1.2
346 root 1.3 if (x >> 16) { x >>= 16; r += 16; }
347     if (x >> 8) { x >>= 8; r += 8; }
348     if (x >> 4) { x >>= 4; r += 4; }
349     if (x >> 2) { x >>= 2; r += 2; }
350     if (x >> 1) { r += 1; }
351 root 1.2
352     return r;
353     }
354    
355     ecb_function_ int ecb_ld64 (uint64_t x) ecb_const;
356     ecb_function_ int ecb_ld64 (uint64_t x)
357     {
358 root 1.3 int r = 0;
359 root 1.2
360 root 1.3 if (x >> 32) { x >>= 32; r += 32; }
361 root 1.1
362 root 1.3 return r + ecb_ld32 (x);
363 root 1.2 }
364     #endif
365 root 1.1
366 root 1.12 ecb_function_ ecb_bool ecb_is_pot32 (uint32_t x) ecb_const;
367     ecb_function_ ecb_bool ecb_is_pot32 (uint32_t x) { return !(x & (x - 1)); }
368     ecb_function_ ecb_bool ecb_is_pot64 (uint64_t x) ecb_const;
369     ecb_function_ ecb_bool ecb_is_pot64 (uint64_t x) { return !(x & (x - 1)); }
370    
371 root 1.11 ecb_function_ uint8_t ecb_bitrev8 (uint8_t x) ecb_const;
372     ecb_function_ uint8_t ecb_bitrev8 (uint8_t x)
373     {
374     return ( (x * 0x0802U & 0x22110U)
375     | (x * 0x8020U & 0x88440U)) * 0x10101U >> 16;
376     }
377    
378     ecb_function_ uint16_t ecb_bitrev16 (uint16_t x) ecb_const;
379     ecb_function_ uint16_t ecb_bitrev16 (uint16_t x)
380     {
381     x = ((x >> 1) & 0x5555) | ((x & 0x5555) << 1);
382     x = ((x >> 2) & 0x3333) | ((x & 0x3333) << 2);
383     x = ((x >> 4) & 0x0f0f) | ((x & 0x0f0f) << 4);
384     x = ( x >> 8 ) | ( x << 8);
385    
386     return x;
387     }
388    
389     ecb_function_ uint32_t ecb_bitrev32 (uint32_t x) ecb_const;
390     ecb_function_ uint32_t ecb_bitrev32 (uint32_t x)
391     {
392     x = ((x >> 1) & 0x55555555) | ((x & 0x55555555) << 1);
393     x = ((x >> 2) & 0x33333333) | ((x & 0x33333333) << 2);
394     x = ((x >> 4) & 0x0f0f0f0f) | ((x & 0x0f0f0f0f) << 4);
395     x = ((x >> 8) & 0x00ff00ff) | ((x & 0x00ff00ff) << 8);
396     x = ( x >> 16 ) | ( x << 16);
397    
398     return x;
399     }
400    
401 root 1.2 /* popcount64 is only available on 64 bit cpus as gcc builtin */
402     /* so for this version we are lazy */
403     ecb_function_ int ecb_popcount64 (uint64_t x) ecb_const;
404     ecb_function_ int
405     ecb_popcount64 (uint64_t x)
406 root 1.1 {
407 root 1.2 return ecb_popcount32 (x) + ecb_popcount32 (x >> 32);
408 root 1.1 }
409    
410 root 1.3 ecb_inline uint8_t ecb_rotl8 (uint8_t x, unsigned int count) ecb_const;
411     ecb_inline uint8_t ecb_rotr8 (uint8_t x, unsigned int count) ecb_const;
412     ecb_inline uint16_t ecb_rotl16 (uint16_t x, unsigned int count) ecb_const;
413     ecb_inline uint16_t ecb_rotr16 (uint16_t x, unsigned int count) ecb_const;
414     ecb_inline uint32_t ecb_rotl32 (uint32_t x, unsigned int count) ecb_const;
415     ecb_inline uint32_t ecb_rotr32 (uint32_t x, unsigned int count) ecb_const;
416     ecb_inline uint64_t ecb_rotl64 (uint64_t x, unsigned int count) ecb_const;
417     ecb_inline uint64_t ecb_rotr64 (uint64_t x, unsigned int count) ecb_const;
418    
419     ecb_inline uint8_t ecb_rotl8 (uint8_t x, unsigned int count) { return (x >> ( 8 - count)) | (x << count); }
420     ecb_inline uint8_t ecb_rotr8 (uint8_t x, unsigned int count) { return (x << ( 8 - count)) | (x >> count); }
421     ecb_inline uint16_t ecb_rotl16 (uint16_t x, unsigned int count) { return (x >> (16 - count)) | (x << count); }
422     ecb_inline uint16_t ecb_rotr16 (uint16_t x, unsigned int count) { return (x << (16 - count)) | (x >> count); }
423     ecb_inline uint32_t ecb_rotl32 (uint32_t x, unsigned int count) { return (x >> (32 - count)) | (x << count); }
424     ecb_inline uint32_t ecb_rotr32 (uint32_t x, unsigned int count) { return (x << (32 - count)) | (x >> count); }
425     ecb_inline uint64_t ecb_rotl64 (uint64_t x, unsigned int count) { return (x >> (64 - count)) | (x << count); }
426     ecb_inline uint64_t ecb_rotr64 (uint64_t x, unsigned int count) { return (x << (64 - count)) | (x >> count); }
427    
428 root 1.1 #if ECB_GCC_VERSION(4,3)
429 root 1.2 #define ecb_bswap16(x) (__builtin_bswap32 (x) >> 16)
430     #define ecb_bswap32(x) __builtin_bswap32 (x)
431     #define ecb_bswap64(x) __builtin_bswap64 (x)
432 root 1.1 #else
433 root 1.3 ecb_function_ uint16_t ecb_bswap16 (uint16_t x) ecb_const;
434     ecb_function_ uint16_t
435     ecb_bswap16 (uint16_t x)
436 root 1.2 {
437 root 1.3 return ecb_rotl16 (x, 8);
438 root 1.2 }
439    
440     ecb_function_ uint32_t ecb_bswap32 (uint32_t x) ecb_const;
441     ecb_function_ uint32_t
442     ecb_bswap32 (uint32_t x)
443     {
444 root 1.3 return (((uint32_t)ecb_bswap16 (x)) << 16) | ecb_bswap16 (x >> 16);
445 root 1.2 }
446    
447     ecb_function_ uint64_t ecb_bswap64 (uint64_t x) ecb_const;
448     ecb_function_ uint64_t
449     ecb_bswap64 (uint64_t x)
450     {
451 root 1.3 return (((uint64_t)ecb_bswap32 (x)) << 32) | ecb_bswap32 (x >> 32);
452 root 1.2 }
453 root 1.1 #endif
454    
455     #if ECB_GCC_VERSION(4,5)
456 root 1.2 #define ecb_unreachable() __builtin_unreachable ()
457 root 1.1 #else
458 root 1.2 /* this seems to work fine, but gcc always emits a warning for it :/ */
459 root 1.11 ecb_inline void ecb_unreachable (void) ecb_noreturn;
460     ecb_inline void ecb_unreachable (void) { }
461 root 1.1 #endif
462    
463 root 1.2 /* try to tell the compiler that some condition is definitely true */
464 root 1.14 #define ecb_assume(cond) if (!(cond)) ecb_unreachable (); else 0
465 root 1.2
466 root 1.11 ecb_inline unsigned char ecb_byteorder_helper (void) ecb_const;
467     ecb_inline unsigned char
468 root 1.1 ecb_byteorder_helper (void)
469     {
470 root 1.14 /* the union code still generates code under pressure in gcc, */
471     /* but less than using pointers, and always seem to */
472     /* successfully return a constant. */
473     /* the reason why we have this horrible preprocessor mess */
474     /* is to avoid it in all cases, at least on common architectures */
475     /* and yes, gcc defines __BYTE_ORDER__, g++ does not */
476     #if __i386 || __i386__ || _M_X86 || __amd64 || __amd64__ || _M_X64
477     return 0x44;
478     #elif __BYTE_ORDER__ && __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
479     return 0x44;
480     #elif __BYTE_ORDER__ && __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
481     retrurn 0x11;
482     #else
483     union
484     {
485     uint32_t i;
486     uint8_t c;
487     } u = { 0x11223344 };
488     return u.c;
489     #endif
490 root 1.1 }
491    
492 root 1.11 ecb_inline ecb_bool ecb_big_endian (void) ecb_const;
493     ecb_inline ecb_bool ecb_big_endian (void) { return ecb_byteorder_helper () == 0x11; }
494     ecb_inline ecb_bool ecb_little_endian (void) ecb_const;
495     ecb_inline ecb_bool ecb_little_endian (void) { return ecb_byteorder_helper () == 0x44; }
496 root 1.1
497 root 1.2 #if ECB_GCC_VERSION(3,0) || ECB_C99
498     #define ecb_mod(m,n) ((m) % (n) + ((m) % (n) < 0 ? (n) : 0))
499 root 1.1 #else
500 root 1.2 #define ecb_mod(m,n) ((m) < 0 ? ((n) - 1 - ((-1 - (m)) % (n))) : ((m) % (n)))
501 root 1.1 #endif
502    
503 root 1.10 #if __cplusplus
504     template<typename T>
505     static inline T ecb_div_rd (T val, T div)
506     {
507     return val < 0 ? - ((-val + div - 1) / div) : (val ) / div;
508     }
509     template<typename T>
510     static inline T ecb_div_ru (T val, T div)
511     {
512     return val < 0 ? - ((-val ) / div) : (val + div - 1) / div;
513     }
514     #else
515     #define ecb_div_rd(val,div) ((val) < 0 ? - ((-(val) + (div) - 1) / (div)) : ((val) ) / (div))
516     #define ecb_div_ru(val,div) ((val) < 0 ? - ((-(val) ) / (div)) : ((val) + (div) - 1) / (div))
517     #endif
518    
519 root 1.1 #if ecb_cplusplus_does_not_suck
520 root 1.2 /* does not work for local types (http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2657.htm) */
521     template<typename T, int N>
522     static inline int ecb_array_length (const T (&arr)[N])
523     {
524     return N;
525     }
526 root 1.1 #else
527 root 1.2 #define ecb_array_length(name) (sizeof (name) / sizeof (name [0]))
528 root 1.1 #endif
529    
530     #endif
531