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Comparing libecb/ecb.h (file contents):
Revision 1.4 by root, Thu May 26 17:26:03 2011 UTC vs.
Revision 1.90 by root, Tue May 29 14:09:49 2012 UTC

1/* 1/*
2 * libecb 2 * libecb - http://software.schmorp.de/pkg/libecb
3 * 3 *
4 * Copyright (©) 2009-2011 Marc Alexander Lehmann 4 * Copyright (©) 2009-2012 Marc Alexander Lehmann <libecb@schmorp.de>
5 * Copyright (©) 2011 Emanuele Giaquinta
5 * All rights reserved. 6 * All rights reserved.
6 * 7 *
7 * Redistribution and use in source and binary forms, with or without modifica- 8 * Redistribution and use in source and binary forms, with or without modifica-
8 * tion, are permitted provided that the following conditions are met: 9 * tion, are permitted provided that the following conditions are met:
9 * 10 *
27 */ 28 */
28 29
29#ifndef ECB_H 30#ifndef ECB_H
30#define ECB_H 31#define ECB_H
31 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
32#define ECB_GCC_VERSION(major,minor) (__GNUC__ > (major) || (__GNUC__ == (major) && __GNUC_MINOR__ >= (minor))) 80 #define ECB_GCC_VERSION(major,minor) (__GNUC__ > (major) || (__GNUC__ == (major) && __GNUC_MINOR__ >= (minor)))
81 #endif
82#endif
33 83
84#define ECB_C99 (__STDC_VERSION__ >= 199901L)
85#define ECB_C11 (__STDC_VERSION__ >= 201112L)
86
87/*****************************************************************************/
88
89/* ECB_NO_THREADS - ecb is not used by multiple threads, ever */
90/* ECB_NO_SMP - ecb might be used in multiple threads, but only on a single cpu */
91
92#if ECB_NO_THREADS
93# define ECB_NO_SMP 1
94#endif
95
96#if ECB_NO_THREADS || ECB_NO_SMP
97 #define ECB_MEMORY_FENCE do { } while (0)
98#endif
99
100#ifndef ECB_MEMORY_FENCE
101 #if ECB_C11 && !defined __STDC_NO_ATOMICS__
102 /* we assume that these memory fences work on all variables/all memory accesses, */
103 /* not just C11 atomics and atomic accesses */
104 #include <stdatomic.h>
105 #define ECB_MEMORY_FENCE atomic_thread_fence (memory_order_acq_rel)
106 #define ECB_MEMORY_FENCE_ACQUIRE atomic_thread_fence (memory_order_acquire)
107 #define ECB_MEMORY_FENCE_RELEASE atomic_thread_fence (memory_order_release)
108 #endif
109#endif
110
111#ifndef ECB_MEMORY_FENCE
112 #if ECB_GCC_VERSION(2,5) || defined __INTEL_COMPILER || (__llvm__ && __GNUC__) || __SUNPRO_C >= 0x5110 || __SUNPRO_CC >= 0x5110
113 #if __i386 || __i386__
114 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("lock; orb $0, -1(%%esp)" : : : "memory")
115 #define ECB_MEMORY_FENCE_ACQUIRE ECB_MEMORY_FENCE /* non-lock xchg might be enough */
116 #define ECB_MEMORY_FENCE_RELEASE do { } while (0) /* unlikely to change in future cpus */
117 #elif __amd64 || __amd64__ || __x86_64 || __x86_64__
118 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("mfence" : : : "memory")
119 #define ECB_MEMORY_FENCE_ACQUIRE __asm__ __volatile__ ("lfence" : : : "memory")
120 #define ECB_MEMORY_FENCE_RELEASE __asm__ __volatile__ ("sfence") /* play safe - not needed in any current cpu */
121 #elif __powerpc__ || __ppc__ || __powerpc64__ || __ppc64__
122 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("sync" : : : "memory")
123 #elif defined __ARM_ARCH_6__ || defined __ARM_ARCH_6J__ \
124 || defined __ARM_ARCH_6K__ || defined __ARM_ARCH_6ZK__
125 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("mcr p15,0,%0,c7,c10,5" : : "r" (0) : "memory")
126 #elif defined __ARM_ARCH_7__ || defined __ARM_ARCH_7A__ \
127 || defined __ARM_ARCH_7M__ || defined __ARM_ARCH_7R__
128 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("dmb" : : : "memory")
129 #elif __sparc || __sparc__
130 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("membar #LoadStore | #LoadLoad | #StoreStore | #StoreLoad | " : : : "memory")
131 #define ECB_MEMORY_FENCE_ACQUIRE __asm__ __volatile__ ("membar #LoadStore | #LoadLoad" : : : "memory")
132 #define ECB_MEMORY_FENCE_RELEASE __asm__ __volatile__ ("membar #LoadStore | #StoreStore")
133 #elif defined __s390__ || defined __s390x__
134 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("bcr 15,0" : : : "memory")
135 #elif defined __mips__
136 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("sync" : : : "memory")
137 #elif defined __alpha__
138 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("mb" : : : "memory")
139 #endif
140 #endif
141#endif
142
143#ifndef ECB_MEMORY_FENCE
144 #if ECB_GCC_VERSION(4,4) || defined __INTEL_COMPILER || defined __clang__
145 #define ECB_MEMORY_FENCE __sync_synchronize ()
146 /*#define ECB_MEMORY_FENCE_ACQUIRE ({ char dummy = 0; __sync_lock_test_and_set (&dummy, 1); }) */
147 /*#define ECB_MEMORY_FENCE_RELEASE ({ char dummy = 1; __sync_lock_release (&dummy ); }) */
148 #elif _MSC_VER >= 1400 /* VC++ 2005 */
149 #pragma intrinsic(_ReadBarrier,_WriteBarrier,_ReadWriteBarrier)
150 #define ECB_MEMORY_FENCE _ReadWriteBarrier ()
151 #define ECB_MEMORY_FENCE_ACQUIRE _ReadWriteBarrier () /* according to msdn, _ReadBarrier is not a load fence */
152 #define ECB_MEMORY_FENCE_RELEASE _WriteBarrier ()
153 #elif defined _WIN32
154 #include <WinNT.h>
155 #define ECB_MEMORY_FENCE MemoryBarrier () /* actually just xchg on x86... scary */
156 #elif __SUNPRO_C >= 0x5110 || __SUNPRO_CC >= 0x5110
157 #include <mbarrier.h>
158 #define ECB_MEMORY_FENCE __machine_rw_barrier ()
159 #define ECB_MEMORY_FENCE_ACQUIRE __machine_r_barrier ()
160 #define ECB_MEMORY_FENCE_RELEASE __machine_w_barrier ()
161 #elif __xlC__
162 #define ECB_MEMORY_FENCE __sync ()
163 #endif
164#endif
165
166#ifndef ECB_MEMORY_FENCE
167 #if !ECB_AVOID_PTHREADS
168 /*
169 * if you get undefined symbol references to pthread_mutex_lock,
170 * or failure to find pthread.h, then you should implement
171 * the ECB_MEMORY_FENCE operations for your cpu/compiler
172 * OR provide pthread.h and link against the posix thread library
173 * of your system.
174 */
175 #include <pthread.h>
176 #define ECB_NEEDS_PTHREADS 1
177 #define ECB_MEMORY_FENCE_NEEDS_PTHREADS 1
178
179 static pthread_mutex_t ecb_mf_lock = PTHREAD_MUTEX_INITIALIZER;
180 #define ECB_MEMORY_FENCE do { pthread_mutex_lock (&ecb_mf_lock); pthread_mutex_unlock (&ecb_mf_lock); } while (0)
181 #endif
182#endif
183
184#if !defined ECB_MEMORY_FENCE_ACQUIRE && defined ECB_MEMORY_FENCE
185 #define ECB_MEMORY_FENCE_ACQUIRE ECB_MEMORY_FENCE
186#endif
187
188#if !defined ECB_MEMORY_FENCE_RELEASE && defined ECB_MEMORY_FENCE
189 #define ECB_MEMORY_FENCE_RELEASE ECB_MEMORY_FENCE
190#endif
191
192/*****************************************************************************/
193
34#ifndef __cplusplus 194#if __cplusplus
35# if __STDC_VERSION__ >= 199901L 195 #define ecb_inline static inline
36# define ECB_INLINE inline 196#elif ECB_GCC_VERSION(2,5)
37typedef _Bool ecb_bool; 197 #define ecb_inline static __inline__
198#elif ECB_C99
199 #define ecb_inline static inline
38# else 200#else
39# define ECB_INLINE inline /* yeah! */ 201 #define ecb_inline static
202#endif
203
204#if ECB_GCC_VERSION(3,3)
205 #define ecb_restrict __restrict__
206#elif ECB_C99
207 #define ecb_restrict restrict
208#else
209 #define ecb_restrict
210#endif
211
40typedef int ecb_bool; 212typedef int ecb_bool;
41# endif
42#endif
43 213
44#define ECB_HEADER_INLINE static ECB_INLINE 214#define ECB_CONCAT_(a, b) a ## b
215#define ECB_CONCAT(a, b) ECB_CONCAT_(a, b)
216#define ECB_STRINGIFY_(a) # a
217#define ECB_STRINGIFY(a) ECB_STRINGIFY_(a)
218
219#define ecb_function_ ecb_inline
45 220
46#if ECB_GCC_VERSION(3,1) 221#if ECB_GCC_VERSION(3,1)
47# define ecb_attribute(attrlist) __attribute__(attrlist) 222 #define ecb_attribute(attrlist) __attribute__(attrlist)
48# define ecb_is_constant(c) __builtin_constant_p (c) 223 #define ecb_is_constant(expr) __builtin_constant_p (expr)
49# define ecb_expect(expr,value) __builtin_expect ((expr),(value)) 224 #define ecb_expect(expr,value) __builtin_expect ((expr),(value))
50# define ecb_prefetch(addr,rw,locality) __builtin_prefetch (addr, rw, locality) 225 #define ecb_prefetch(addr,rw,locality) __builtin_prefetch (addr, rw, locality)
51#else 226#else
52# define ecb_attribute(attrlist) 227 #define ecb_attribute(attrlist)
53# define ecb_is_constant(c) 0 228 #define ecb_is_constant(expr) 0
54# define ecb_expect(expr,value) (expr) 229 #define ecb_expect(expr,value) (expr)
55# define ecb_prefetch(addr,rw,locality) 230 #define ecb_prefetch(addr,rw,locality)
56#endif 231#endif
57 232
58/* no emulation for ecb_decltype */ 233/* no emulation for ecb_decltype */
59#if ECB_GCC_VERSION(4,5) 234#if ECB_GCC_VERSION(4,5)
60# define ecb_decltype(x) __decltype(x) 235 #define ecb_decltype(x) __decltype(x)
61#elif ECB_GCC_VERSION(3,0) 236#elif ECB_GCC_VERSION(3,0)
62# define ecb_decltype(x) typeof(x) 237 #define ecb_decltype(x) __typeof(x)
63#endif 238#endif
64 239
65#define ecb_noinline ecb_attribute ((noinline)) 240#define ecb_noinline ecb_attribute ((__noinline__))
66#define ecb_noreturn ecb_attribute ((noreturn))
67#define ecb_unused ecb_attribute ((unused)) 241#define ecb_unused ecb_attribute ((__unused__))
68#define ecb_const ecb_attribute ((const)) 242#define ecb_const ecb_attribute ((__const__))
69#define ecb_pure ecb_attribute ((pure)) 243#define ecb_pure ecb_attribute ((__pure__))
70#define ecb_hot ecb_attribute ((hot)) /* 4.3 */
71#define ecb_cold ecb_attribute ((cold)) /* 4.3 */
72 244
245#if ECB_C11
246 #define ecb_noreturn _Noreturn
247#else
248 #define ecb_noreturn ecb_attribute ((__noreturn__))
249#endif
250
73#if ECB_GCC_VERSION(4,5) 251#if ECB_GCC_VERSION(4,3)
74# define ecb_unreachable() __builtin_unreachable () 252 #define ecb_artificial ecb_attribute ((__artificial__))
253 #define ecb_hot ecb_attribute ((__hot__))
254 #define ecb_cold ecb_attribute ((__cold__))
75#else 255#else
76/* this seems to work fine, but gcc always emits a warning for it :/ */ 256 #define ecb_artificial
77ECB_HEADER_INLINE void ecb_unreachable () ecb_attribute ((noreturn)); 257 #define ecb_hot
78ECB_HEADER_INLINE void ecb_unreachable () { } 258 #define ecb_cold
79#endif 259#endif
80 260
81/* put into ifs if you are very sure that the expression */ 261/* put around conditional expressions if you are very sure that the */
82/* is mostly true or mosty false. note that these return */ 262/* expression is mostly true or mostly false. note that these return */
83/* booleans, not the expression. */ 263/* booleans, not the expression. */
84#define ecb_expect_false(expr) ecb_expect ((expr) ? 1 : 0, 0) 264#define ecb_expect_false(expr) ecb_expect (!!(expr), 0)
85#define ecb_expect_true(expr) ecb_expect ((expr) ? 1 : 0, 1) 265#define ecb_expect_true(expr) ecb_expect (!!(expr), 1)
86 266/* for compatibility to the rest of the world */
87/* try to tell the compiler that some condition is definitely true */ 267#define ecb_likely(expr) ecb_expect_true (expr)
88#define ecb_assume(cond) do { if (!(cond)) unreachable (); } while (0) 268#define ecb_unlikely(expr) ecb_expect_false (expr)
89 269
90/* count trailing zero bits and count # of one bits */ 270/* count trailing zero bits and count # of one bits */
91#if ECB_GCC_VERSION(3,4) 271#if ECB_GCC_VERSION(3,4)
92ECB_HEADER_INLINE int ecb_ctz32 (unsigned int x) { return __builtin_ctz (x); } 272 /* we assume int == 32 bit, long == 32 or 64 bit and long long == 64 bit */
93ECB_HEADER_INLINE int ecb_popcount32 (unsigned int x) { return __builtin_popcount (x); } 273 #define ecb_ld32(x) (__builtin_clz (x) ^ 31)
274 #define ecb_ld64(x) (__builtin_clzll (x) ^ 63)
275 #define ecb_ctz32(x) __builtin_ctz (x)
276 #define ecb_ctz64(x) __builtin_ctzll (x)
277 #define ecb_popcount32(x) __builtin_popcount (x)
278 /* no popcountll */
94#else 279#else
95ECB_HEADER_INLINE 280 ecb_function_ int ecb_ctz32 (uint32_t x) ecb_const;
96ecb_ctz32 (unsigned int x) ecb_const 281 ecb_function_ int
282 ecb_ctz32 (uint32_t x)
283 {
284 int r = 0;
285
286 x &= ~x + 1; /* this isolates the lowest bit */
287
288#if ECB_branchless_on_i386
289 r += !!(x & 0xaaaaaaaa) << 0;
290 r += !!(x & 0xcccccccc) << 1;
291 r += !!(x & 0xf0f0f0f0) << 2;
292 r += !!(x & 0xff00ff00) << 3;
293 r += !!(x & 0xffff0000) << 4;
294#else
295 if (x & 0xaaaaaaaa) r += 1;
296 if (x & 0xcccccccc) r += 2;
297 if (x & 0xf0f0f0f0) r += 4;
298 if (x & 0xff00ff00) r += 8;
299 if (x & 0xffff0000) r += 16;
300#endif
301
302 return r;
303 }
304
305 ecb_function_ int ecb_ctz64 (uint64_t x) ecb_const;
306 ecb_function_ int
307 ecb_ctz64 (uint64_t x)
308 {
309 int shift = x & 0xffffffffU ? 0 : 32;
310 return ecb_ctz32 (x >> shift) + shift;
311 }
312
313 ecb_function_ int ecb_popcount32 (uint32_t x) ecb_const;
314 ecb_function_ int
315 ecb_popcount32 (uint32_t x)
316 {
317 x -= (x >> 1) & 0x55555555;
318 x = ((x >> 2) & 0x33333333) + (x & 0x33333333);
319 x = ((x >> 4) + x) & 0x0f0f0f0f;
320 x *= 0x01010101;
321
322 return x >> 24;
323 }
324
325 ecb_function_ int ecb_ld32 (uint32_t x) ecb_const;
326 ecb_function_ int ecb_ld32 (uint32_t x)
327 {
328 int r = 0;
329
330 if (x >> 16) { x >>= 16; r += 16; }
331 if (x >> 8) { x >>= 8; r += 8; }
332 if (x >> 4) { x >>= 4; r += 4; }
333 if (x >> 2) { x >>= 2; r += 2; }
334 if (x >> 1) { r += 1; }
335
336 return r;
337 }
338
339 ecb_function_ int ecb_ld64 (uint64_t x) ecb_const;
340 ecb_function_ int ecb_ld64 (uint64_t x)
341 {
342 int r = 0;
343
344 if (x >> 32) { x >>= 32; r += 32; }
345
346 return r + ecb_ld32 (x);
347 }
348#endif
349
350ecb_function_ ecb_bool ecb_is_pot32 (uint32_t x) ecb_const;
351ecb_function_ ecb_bool ecb_is_pot32 (uint32_t x) { return !(x & (x - 1)); }
352ecb_function_ ecb_bool ecb_is_pot64 (uint64_t x) ecb_const;
353ecb_function_ ecb_bool ecb_is_pot64 (uint64_t x) { return !(x & (x - 1)); }
354
355ecb_function_ uint8_t ecb_bitrev8 (uint8_t x) ecb_const;
356ecb_function_ uint8_t ecb_bitrev8 (uint8_t x)
97{ 357{
98 int r = 0; 358 return ( (x * 0x0802U & 0x22110U)
99 359 | (x * 0x8020U & 0x88440U)) * 0x10101U >> 16;
100 x &= -x; /* this isolates the lowest bit */
101
102 if (x & 0xaaaaaaaa) r += 1;
103 if (x & 0xcccccccc) r += 2;
104 if (x & 0xf0f0f0f0) r += 4;
105 if (x & 0xff00ff00) r += 8;
106 if (x & 0xffff0000) r += 16;
107
108 return r;
109} 360}
110 361
111ECB_HEADER_INLINE 362ecb_function_ uint16_t ecb_bitrev16 (uint16_t x) ecb_const;
112ecb_popcount32 (unsigned int x) ecb_const 363ecb_function_ uint16_t ecb_bitrev16 (uint16_t x)
113{ 364{
114 x -= (x >> 1) & 0x55555555; 365 x = ((x >> 1) & 0x5555) | ((x & 0x5555) << 1);
115 x = ((x >> 2) & 0x33333333) + (x & 0x33333333); 366 x = ((x >> 2) & 0x3333) | ((x & 0x3333) << 2);
116 x = ((x >> 4) + x) & 0x0f0f0f0f; 367 x = ((x >> 4) & 0x0f0f) | ((x & 0x0f0f) << 4);
117 x *= 0x01010101; 368 x = ( x >> 8 ) | ( x << 8);
118 369
119 return x >> 24; 370 return x;
120} 371}
121#endif
122 372
123ECB_HEADER_INLINE unsigned char 373ecb_function_ uint32_t ecb_bitrev32 (uint32_t x) ecb_const;
374ecb_function_ uint32_t ecb_bitrev32 (uint32_t x)
375{
376 x = ((x >> 1) & 0x55555555) | ((x & 0x55555555) << 1);
377 x = ((x >> 2) & 0x33333333) | ((x & 0x33333333) << 2);
378 x = ((x >> 4) & 0x0f0f0f0f) | ((x & 0x0f0f0f0f) << 4);
379 x = ((x >> 8) & 0x00ff00ff) | ((x & 0x00ff00ff) << 8);
380 x = ( x >> 16 ) | ( x << 16);
381
382 return x;
383}
384
385/* popcount64 is only available on 64 bit cpus as gcc builtin */
386/* so for this version we are lazy */
387ecb_function_ int ecb_popcount64 (uint64_t x) ecb_const;
388ecb_function_ int
389ecb_popcount64 (uint64_t x)
390{
391 return ecb_popcount32 (x) + ecb_popcount32 (x >> 32);
392}
393
394ecb_inline uint8_t ecb_rotl8 (uint8_t x, unsigned int count) ecb_const;
395ecb_inline uint8_t ecb_rotr8 (uint8_t x, unsigned int count) ecb_const;
396ecb_inline uint16_t ecb_rotl16 (uint16_t x, unsigned int count) ecb_const;
397ecb_inline uint16_t ecb_rotr16 (uint16_t x, unsigned int count) ecb_const;
398ecb_inline uint32_t ecb_rotl32 (uint32_t x, unsigned int count) ecb_const;
399ecb_inline uint32_t ecb_rotr32 (uint32_t x, unsigned int count) ecb_const;
400ecb_inline uint64_t ecb_rotl64 (uint64_t x, unsigned int count) ecb_const;
401ecb_inline uint64_t ecb_rotr64 (uint64_t x, unsigned int count) ecb_const;
402
403ecb_inline uint8_t ecb_rotl8 (uint8_t x, unsigned int count) { return (x >> ( 8 - count)) | (x << count); }
404ecb_inline uint8_t ecb_rotr8 (uint8_t x, unsigned int count) { return (x << ( 8 - count)) | (x >> count); }
405ecb_inline uint16_t ecb_rotl16 (uint16_t x, unsigned int count) { return (x >> (16 - count)) | (x << count); }
406ecb_inline uint16_t ecb_rotr16 (uint16_t x, unsigned int count) { return (x << (16 - count)) | (x >> count); }
407ecb_inline uint32_t ecb_rotl32 (uint32_t x, unsigned int count) { return (x >> (32 - count)) | (x << count); }
408ecb_inline uint32_t ecb_rotr32 (uint32_t x, unsigned int count) { return (x << (32 - count)) | (x >> count); }
409ecb_inline uint64_t ecb_rotl64 (uint64_t x, unsigned int count) { return (x >> (64 - count)) | (x << count); }
410ecb_inline uint64_t ecb_rotr64 (uint64_t x, unsigned int count) { return (x << (64 - count)) | (x >> count); }
411
412#if ECB_GCC_VERSION(4,3)
413 #define ecb_bswap16(x) (__builtin_bswap32 (x) >> 16)
414 #define ecb_bswap32(x) __builtin_bswap32 (x)
415 #define ecb_bswap64(x) __builtin_bswap64 (x)
416#else
417 ecb_function_ uint16_t ecb_bswap16 (uint16_t x) ecb_const;
418 ecb_function_ uint16_t
419 ecb_bswap16 (uint16_t x)
420 {
421 return ecb_rotl16 (x, 8);
422 }
423
424 ecb_function_ uint32_t ecb_bswap32 (uint32_t x) ecb_const;
425 ecb_function_ uint32_t
426 ecb_bswap32 (uint32_t x)
427 {
428 return (((uint32_t)ecb_bswap16 (x)) << 16) | ecb_bswap16 (x >> 16);
429 }
430
431 ecb_function_ uint64_t ecb_bswap64 (uint64_t x) ecb_const;
432 ecb_function_ uint64_t
433 ecb_bswap64 (uint64_t x)
434 {
435 return (((uint64_t)ecb_bswap32 (x)) << 32) | ecb_bswap32 (x >> 32);
436 }
437#endif
438
439#if ECB_GCC_VERSION(4,5)
440 #define ecb_unreachable() __builtin_unreachable ()
441#else
442 /* this seems to work fine, but gcc always emits a warning for it :/ */
443 ecb_inline void ecb_unreachable (void) ecb_noreturn;
444 ecb_inline void ecb_unreachable (void) { }
445#endif
446
447/* try to tell the compiler that some condition is definitely true */
448#define ecb_assume(cond) do { if (!(cond)) ecb_unreachable (); } while (0)
449
450ecb_inline unsigned char ecb_byteorder_helper (void) ecb_const;
451ecb_inline unsigned char
124ecb_byteorder_helper () ecb_const 452ecb_byteorder_helper (void)
125{ 453{
126 const uint32_t u = 0x11223344; 454 const uint32_t u = 0x11223344;
127 return *(unsigned char *)&u; 455 return *(unsigned char *)&u;
128} 456}
129 457
458ecb_inline ecb_bool ecb_big_endian (void) ecb_const;
130ECB_HEADER_INLINE ecb_bool ecb_big_endian () ecb_const { return ecb_byteorder_helper () == 0x11; }; 459ecb_inline ecb_bool ecb_big_endian (void) { return ecb_byteorder_helper () == 0x11; }
460ecb_inline ecb_bool ecb_little_endian (void) ecb_const;
131ECB_HEADER_INLINE ecb_bool ecb_little_endian () ecb_const { return ecb_byteorder_helper () == 0x44; }; 461ecb_inline ecb_bool ecb_little_endian (void) { return ecb_byteorder_helper () == 0x44; }
132 462
463#if ECB_GCC_VERSION(3,0) || ECB_C99
464 #define ecb_mod(m,n) ((m) % (n) + ((m) % (n) < 0 ? (n) : 0))
465#else
466 #define ecb_mod(m,n) ((m) < 0 ? ((n) - 1 - ((-1 - (m)) % (n))) : ((m) % (n)))
133#endif 467#endif
134 468
469#if __cplusplus
470 template<typename T>
471 static inline T ecb_div_rd (T val, T div)
472 {
473 return val < 0 ? - ((-val + div - 1) / div) : (val ) / div;
474 }
475 template<typename T>
476 static inline T ecb_div_ru (T val, T div)
477 {
478 return val < 0 ? - ((-val ) / div) : (val + div - 1) / div;
479 }
480#else
481 #define ecb_div_rd(val,div) ((val) < 0 ? - ((-(val) + (div) - 1) / (div)) : ((val) ) / (div))
482 #define ecb_div_ru(val,div) ((val) < 0 ? - ((-(val) ) / (div)) : ((val) + (div) - 1) / (div))
483#endif
484
485#if ecb_cplusplus_does_not_suck
486 /* does not work for local types (http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2657.htm) */
487 template<typename T, int N>
488 static inline int ecb_array_length (const T (&arr)[N])
489 {
490 return N;
491 }
492#else
493 #define ecb_array_length(name) (sizeof (name) / sizeof (name [0]))
494#endif
495
496#endif
497

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