ViewVC Help
View File | Revision Log | Show Annotations | Download File
/cvs/libecb/ecb.h
(Generate patch)

Comparing libecb/ecb.h (file contents):
Revision 1.1 by root, Thu May 26 16:41:12 2011 UTC vs.
Revision 1.92 by root, Tue May 29 17:17:56 2012 UTC

1/* 1/*
2 * libecb 2 * libecb - http://software.schmorp.de/pkg/libecb
3 * 3 *
4 * Copyright (c) 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
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_THREADS || 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 #define ECB_MEMORY_FENCE atomic_thread_fence (memory_order_acq_rel)
110 #define ECB_MEMORY_FENCE_ACQUIRE atomic_thread_fence (memory_order_acquire)
111 #define ECB_MEMORY_FENCE_RELEASE atomic_thread_fence (memory_order_release)
112 #endif
113#endif
114
115#ifndef ECB_MEMORY_FENCE_RELEASE
116 #if ECB_GCC_VERSION(4,7)
117 #define ECB_MEMORY_FENCE __atomic_thread_fence (__ATOMIC_ACQ_REL)
118 #define ECB_MEMORY_FENCE_ACQUIRE __atomic_thread_fence (__ATOMIC_ACQUIRE)
119 #define ECB_MEMORY_FENCE_RELEASE __atomic_thread_fence (__ATOMIC_RELEASE)
120 #endif
121#endif
122
123#ifndef ECB_MEMORY_FENCE
124 #if ECB_GCC_VERSION(2,5) || defined __INTEL_COMPILER || (__llvm__ && __GNUC__) || __SUNPRO_C >= 0x5110 || __SUNPRO_CC >= 0x5110
125 #if __i386 || __i386__
126 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("lock; orb $0, -1(%%esp)" : : : "memory")
127 #define ECB_MEMORY_FENCE_ACQUIRE ECB_MEMORY_FENCE /* non-lock xchg might be enough */
128 #define ECB_MEMORY_FENCE_RELEASE do { } while (0) /* unlikely to change in future cpus */
129 #elif __amd64 || __amd64__ || __x86_64 || __x86_64__
130 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("mfence" : : : "memory")
131 #define ECB_MEMORY_FENCE_ACQUIRE __asm__ __volatile__ ("lfence" : : : "memory")
132 #define ECB_MEMORY_FENCE_RELEASE __asm__ __volatile__ ("sfence") /* play safe - not needed in any current cpu */
133 #elif __powerpc__ || __ppc__ || __powerpc64__ || __ppc64__
134 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("sync" : : : "memory")
135 #elif defined __ARM_ARCH_6__ || defined __ARM_ARCH_6J__ \
136 || defined __ARM_ARCH_6K__ || defined __ARM_ARCH_6ZK__
137 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("mcr p15,0,%0,c7,c10,5" : : "r" (0) : "memory")
138 #elif defined __ARM_ARCH_7__ || defined __ARM_ARCH_7A__ \
139 || defined __ARM_ARCH_7M__ || defined __ARM_ARCH_7R__
140 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("dmb" : : : "memory")
141 #elif __sparc || __sparc__
142 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("membar #LoadStore | #LoadLoad | #StoreStore | #StoreLoad | " : : : "memory")
143 #define ECB_MEMORY_FENCE_ACQUIRE __asm__ __volatile__ ("membar #LoadStore | #LoadLoad" : : : "memory")
144 #define ECB_MEMORY_FENCE_RELEASE __asm__ __volatile__ ("membar #LoadStore | #StoreStore")
145 #elif defined __s390__ || defined __s390x__
146 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("bcr 15,0" : : : "memory")
147 #elif defined __mips__
148 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("sync" : : : "memory")
149 #elif defined __alpha__
150 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("mb" : : : "memory")
151 #endif
152 #endif
153#endif
154
155#ifndef ECB_MEMORY_FENCE
156 #if ECB_GCC_VERSION(4,4) || defined __INTEL_COMPILER || defined __clang__
157 #define ECB_MEMORY_FENCE __sync_synchronize ()
158 /*#define ECB_MEMORY_FENCE_ACQUIRE ({ char dummy = 0; __sync_lock_test_and_set (&dummy, 1); }) */
159 /*#define ECB_MEMORY_FENCE_RELEASE ({ char dummy = 1; __sync_lock_release (&dummy ); }) */
160 #elif _MSC_VER >= 1400 /* VC++ 2005 */
161 #pragma intrinsic(_ReadBarrier,_WriteBarrier,_ReadWriteBarrier)
162 #define ECB_MEMORY_FENCE _ReadWriteBarrier ()
163 #define ECB_MEMORY_FENCE_ACQUIRE _ReadWriteBarrier () /* according to msdn, _ReadBarrier is not a load fence */
164 #define ECB_MEMORY_FENCE_RELEASE _WriteBarrier ()
165 #elif defined _WIN32
166 #include <WinNT.h>
167 #define ECB_MEMORY_FENCE MemoryBarrier () /* actually just xchg on x86... scary */
168 #elif __SUNPRO_C >= 0x5110 || __SUNPRO_CC >= 0x5110
169 #include <mbarrier.h>
170 #define ECB_MEMORY_FENCE __machine_rw_barrier ()
171 #define ECB_MEMORY_FENCE_ACQUIRE __machine_r_barrier ()
172 #define ECB_MEMORY_FENCE_RELEASE __machine_w_barrier ()
173 #elif __xlC__
174 #define ECB_MEMORY_FENCE __sync ()
175 #endif
176#endif
177
178#ifndef ECB_MEMORY_FENCE
179 #if !ECB_AVOID_PTHREADS
180 /*
181 * if you get undefined symbol references to pthread_mutex_lock,
182 * or failure to find pthread.h, then you should implement
183 * the ECB_MEMORY_FENCE operations for your cpu/compiler
184 * OR provide pthread.h and link against the posix thread library
185 * of your system.
186 */
187 #include <pthread.h>
188 #define ECB_NEEDS_PTHREADS 1
189 #define ECB_MEMORY_FENCE_NEEDS_PTHREADS 1
190
191 static pthread_mutex_t ecb_mf_lock = PTHREAD_MUTEX_INITIALIZER;
192 #define ECB_MEMORY_FENCE do { pthread_mutex_lock (&ecb_mf_lock); pthread_mutex_unlock (&ecb_mf_lock); } while (0)
193 #endif
194#endif
195
196#if !defined ECB_MEMORY_FENCE_ACQUIRE && defined ECB_MEMORY_FENCE
197 #define ECB_MEMORY_FENCE_ACQUIRE ECB_MEMORY_FENCE
198#endif
199
200#if !defined ECB_MEMORY_FENCE_RELEASE && defined ECB_MEMORY_FENCE
201 #define ECB_MEMORY_FENCE_RELEASE ECB_MEMORY_FENCE
202#endif
203
204/*****************************************************************************/
205
206#if __cplusplus
207 #define ecb_inline static inline
208#elif ECB_GCC_VERSION(2,5)
209 #define ecb_inline static __inline__
210#elif ECB_C99
211 #define ecb_inline static inline
212#else
213 #define ecb_inline static
214#endif
215
216#if ECB_GCC_VERSION(3,3)
217 #define ecb_restrict __restrict__
218#elif ECB_C99
219 #define ecb_restrict restrict
220#else
221 #define ecb_restrict
222#endif
223
224typedef int ecb_bool;
225
226#define ECB_CONCAT_(a, b) a ## b
227#define ECB_CONCAT(a, b) ECB_CONCAT_(a, b)
228#define ECB_STRINGIFY_(a) # a
229#define ECB_STRINGIFY(a) ECB_STRINGIFY_(a)
230
231#define ecb_function_ ecb_inline
33 232
34#if ECB_GCC_VERSION(3,1) 233#if ECB_GCC_VERSION(3,1)
35# define ecb_attribute(attrlist) __attribute__(attrlist) 234 #define ecb_attribute(attrlist) __attribute__(attrlist)
36# define ecb_is_constant(c) __builtin_constant_p (c) 235 #define ecb_is_constant(expr) __builtin_constant_p (expr)
37# define ecb_expect(expr,value) __builtin_expect ((expr),(value)) 236 #define ecb_expect(expr,value) __builtin_expect ((expr),(value))
38# define ecb_prefetch(addr,rw,locality) __builtin_prefetch (addr, rw, locality) 237 #define ecb_prefetch(addr,rw,locality) __builtin_prefetch (addr, rw, locality)
39#else 238#else
40# define ecb_attribute(attrlist) 239 #define ecb_attribute(attrlist)
41# define ecb_is_constant(c) 0 240 #define ecb_is_constant(expr) 0
42# define ecb_expect(expr,value) (expr) 241 #define ecb_expect(expr,value) (expr)
43# define ecb_prefetch(addr,rw,locality) 242 #define ecb_prefetch(addr,rw,locality)
44#endif 243#endif
45 244
245/* no emulation for ecb_decltype */
46#if ECB_GCC_VERSION(4,5) 246#if ECB_GCC_VERSION(4,5)
47# define ecb_decltype(x) __decltype(x) 247 #define ecb_decltype(x) __decltype(x)
48#elif ECB_GCC_VERSION(3,0) 248#elif ECB_GCC_VERSION(3,0)
49# define ecb_decltype(x) typeof(x) 249 #define ecb_decltype(x) __typeof(x)
50#endif 250#endif
51 251
52#define ecb_noinline ecb_attribute ((noinline)) 252#define ecb_noinline ecb_attribute ((__noinline__))
53#define ecb_noreturn ecb_attribute ((noreturn))
54#define ecb_unused ecb_attribute ((unused)) 253#define ecb_unused ecb_attribute ((__unused__))
55#define ecb_const ecb_attribute ((const)) 254#define ecb_const ecb_attribute ((__const__))
56#define ecb_pure ecb_attribute ((pure)) 255#define ecb_pure ecb_attribute ((__pure__))
256
257#if ECB_C11
258 #define ecb_noreturn _Noreturn
259#else
260 #define ecb_noreturn ecb_attribute ((__noreturn__))
261#endif
262
263#if ECB_GCC_VERSION(4,3)
264 #define ecb_artificial ecb_attribute ((__artificial__))
57#define ecb_hot ecb_attribute ((hot)) // 4.3 265 #define ecb_hot ecb_attribute ((__hot__))
58#define ecb_cold ecb_attribute ((cold)) // 4.3 266 #define ecb_cold ecb_attribute ((__cold__))
267#else
268 #define ecb_artificial
269 #define ecb_hot
270 #define ecb_cold
271#endif
272
273/* put around conditional expressions if you are very sure that the */
274/* expression is mostly true or mostly false. note that these return */
275/* booleans, not the expression. */
276#define ecb_expect_false(expr) ecb_expect (!!(expr), 0)
277#define ecb_expect_true(expr) ecb_expect (!!(expr), 1)
278/* for compatibility to the rest of the world */
279#define ecb_likely(expr) ecb_expect_true (expr)
280#define ecb_unlikely(expr) ecb_expect_false (expr)
281
282/* count trailing zero bits and count # of one bits */
283#if ECB_GCC_VERSION(3,4)
284 /* we assume int == 32 bit, long == 32 or 64 bit and long long == 64 bit */
285 #define ecb_ld32(x) (__builtin_clz (x) ^ 31)
286 #define ecb_ld64(x) (__builtin_clzll (x) ^ 63)
287 #define ecb_ctz32(x) __builtin_ctz (x)
288 #define ecb_ctz64(x) __builtin_ctzll (x)
289 #define ecb_popcount32(x) __builtin_popcount (x)
290 /* no popcountll */
291#else
292 ecb_function_ int ecb_ctz32 (uint32_t x) ecb_const;
293 ecb_function_ int
294 ecb_ctz32 (uint32_t x)
295 {
296 int r = 0;
297
298 x &= ~x + 1; /* this isolates the lowest bit */
299
300#if ECB_branchless_on_i386
301 r += !!(x & 0xaaaaaaaa) << 0;
302 r += !!(x & 0xcccccccc) << 1;
303 r += !!(x & 0xf0f0f0f0) << 2;
304 r += !!(x & 0xff00ff00) << 3;
305 r += !!(x & 0xffff0000) << 4;
306#else
307 if (x & 0xaaaaaaaa) r += 1;
308 if (x & 0xcccccccc) r += 2;
309 if (x & 0xf0f0f0f0) r += 4;
310 if (x & 0xff00ff00) r += 8;
311 if (x & 0xffff0000) r += 16;
312#endif
313
314 return r;
315 }
316
317 ecb_function_ int ecb_ctz64 (uint64_t x) ecb_const;
318 ecb_function_ int
319 ecb_ctz64 (uint64_t x)
320 {
321 int shift = x & 0xffffffffU ? 0 : 32;
322 return ecb_ctz32 (x >> shift) + shift;
323 }
324
325 ecb_function_ int ecb_popcount32 (uint32_t x) ecb_const;
326 ecb_function_ int
327 ecb_popcount32 (uint32_t x)
328 {
329 x -= (x >> 1) & 0x55555555;
330 x = ((x >> 2) & 0x33333333) + (x & 0x33333333);
331 x = ((x >> 4) + x) & 0x0f0f0f0f;
332 x *= 0x01010101;
333
334 return x >> 24;
335 }
336
337 ecb_function_ int ecb_ld32 (uint32_t x) ecb_const;
338 ecb_function_ int ecb_ld32 (uint32_t x)
339 {
340 int r = 0;
341
342 if (x >> 16) { x >>= 16; r += 16; }
343 if (x >> 8) { x >>= 8; r += 8; }
344 if (x >> 4) { x >>= 4; r += 4; }
345 if (x >> 2) { x >>= 2; r += 2; }
346 if (x >> 1) { r += 1; }
347
348 return r;
349 }
350
351 ecb_function_ int ecb_ld64 (uint64_t x) ecb_const;
352 ecb_function_ int ecb_ld64 (uint64_t x)
353 {
354 int r = 0;
355
356 if (x >> 32) { x >>= 32; r += 32; }
357
358 return r + ecb_ld32 (x);
359 }
360#endif
361
362ecb_function_ ecb_bool ecb_is_pot32 (uint32_t x) ecb_const;
363ecb_function_ ecb_bool ecb_is_pot32 (uint32_t x) { return !(x & (x - 1)); }
364ecb_function_ ecb_bool ecb_is_pot64 (uint64_t x) ecb_const;
365ecb_function_ ecb_bool ecb_is_pot64 (uint64_t x) { return !(x & (x - 1)); }
366
367ecb_function_ uint8_t ecb_bitrev8 (uint8_t x) ecb_const;
368ecb_function_ uint8_t ecb_bitrev8 (uint8_t x)
369{
370 return ( (x * 0x0802U & 0x22110U)
371 | (x * 0x8020U & 0x88440U)) * 0x10101U >> 16;
372}
373
374ecb_function_ uint16_t ecb_bitrev16 (uint16_t x) ecb_const;
375ecb_function_ uint16_t ecb_bitrev16 (uint16_t x)
376{
377 x = ((x >> 1) & 0x5555) | ((x & 0x5555) << 1);
378 x = ((x >> 2) & 0x3333) | ((x & 0x3333) << 2);
379 x = ((x >> 4) & 0x0f0f) | ((x & 0x0f0f) << 4);
380 x = ( x >> 8 ) | ( x << 8);
381
382 return x;
383}
384
385ecb_function_ uint32_t ecb_bitrev32 (uint32_t x) ecb_const;
386ecb_function_ uint32_t ecb_bitrev32 (uint32_t x)
387{
388 x = ((x >> 1) & 0x55555555) | ((x & 0x55555555) << 1);
389 x = ((x >> 2) & 0x33333333) | ((x & 0x33333333) << 2);
390 x = ((x >> 4) & 0x0f0f0f0f) | ((x & 0x0f0f0f0f) << 4);
391 x = ((x >> 8) & 0x00ff00ff) | ((x & 0x00ff00ff) << 8);
392 x = ( x >> 16 ) | ( x << 16);
393
394 return x;
395}
396
397/* popcount64 is only available on 64 bit cpus as gcc builtin */
398/* so for this version we are lazy */
399ecb_function_ int ecb_popcount64 (uint64_t x) ecb_const;
400ecb_function_ int
401ecb_popcount64 (uint64_t x)
402{
403 return ecb_popcount32 (x) + ecb_popcount32 (x >> 32);
404}
405
406ecb_inline uint8_t ecb_rotl8 (uint8_t x, unsigned int count) ecb_const;
407ecb_inline uint8_t ecb_rotr8 (uint8_t x, unsigned int count) ecb_const;
408ecb_inline uint16_t ecb_rotl16 (uint16_t x, unsigned int count) ecb_const;
409ecb_inline uint16_t ecb_rotr16 (uint16_t x, unsigned int count) ecb_const;
410ecb_inline uint32_t ecb_rotl32 (uint32_t x, unsigned int count) ecb_const;
411ecb_inline uint32_t ecb_rotr32 (uint32_t x, unsigned int count) ecb_const;
412ecb_inline uint64_t ecb_rotl64 (uint64_t x, unsigned int count) ecb_const;
413ecb_inline uint64_t ecb_rotr64 (uint64_t x, unsigned int count) ecb_const;
414
415ecb_inline uint8_t ecb_rotl8 (uint8_t x, unsigned int count) { return (x >> ( 8 - count)) | (x << count); }
416ecb_inline uint8_t ecb_rotr8 (uint8_t x, unsigned int count) { return (x << ( 8 - count)) | (x >> count); }
417ecb_inline uint16_t ecb_rotl16 (uint16_t x, unsigned int count) { return (x >> (16 - count)) | (x << count); }
418ecb_inline uint16_t ecb_rotr16 (uint16_t x, unsigned int count) { return (x << (16 - count)) | (x >> count); }
419ecb_inline uint32_t ecb_rotl32 (uint32_t x, unsigned int count) { return (x >> (32 - count)) | (x << count); }
420ecb_inline uint32_t ecb_rotr32 (uint32_t x, unsigned int count) { return (x << (32 - count)) | (x >> count); }
421ecb_inline uint64_t ecb_rotl64 (uint64_t x, unsigned int count) { return (x >> (64 - count)) | (x << count); }
422ecb_inline uint64_t ecb_rotr64 (uint64_t x, unsigned int count) { return (x << (64 - count)) | (x >> count); }
423
424#if ECB_GCC_VERSION(4,3)
425 #define ecb_bswap16(x) (__builtin_bswap32 (x) >> 16)
426 #define ecb_bswap32(x) __builtin_bswap32 (x)
427 #define ecb_bswap64(x) __builtin_bswap64 (x)
428#else
429 ecb_function_ uint16_t ecb_bswap16 (uint16_t x) ecb_const;
430 ecb_function_ uint16_t
431 ecb_bswap16 (uint16_t x)
432 {
433 return ecb_rotl16 (x, 8);
434 }
435
436 ecb_function_ uint32_t ecb_bswap32 (uint32_t x) ecb_const;
437 ecb_function_ uint32_t
438 ecb_bswap32 (uint32_t x)
439 {
440 return (((uint32_t)ecb_bswap16 (x)) << 16) | ecb_bswap16 (x >> 16);
441 }
442
443 ecb_function_ uint64_t ecb_bswap64 (uint64_t x) ecb_const;
444 ecb_function_ uint64_t
445 ecb_bswap64 (uint64_t x)
446 {
447 return (((uint64_t)ecb_bswap32 (x)) << 32) | ecb_bswap32 (x >> 32);
448 }
449#endif
59 450
60#if ECB_GCC_VERSION(4,5) 451#if ECB_GCC_VERSION(4,5)
61# define ecb_unreachable() __builtin_unreachable () 452 #define ecb_unreachable() __builtin_unreachable ()
62#else 453#else
63 // this seems to work fine, but gcc always emits a warning for it :/ 454 /* this seems to work fine, but gcc always emits a warning for it :/ */
64 static inline void ecb_unreachable () ecb_attribute ((noreturn)); 455 ecb_inline void ecb_unreachable (void) ecb_noreturn;
65 static inline void ecb_unreachable () { } 456 ecb_inline void ecb_unreachable (void) { }
66#endif 457#endif
67 458
68// put into ifs if you are very sure that the expression
69// is mostly true or mosty false. note that these return
70// booleans, not the expression.
71#define ecb_expect_false(expr) ecb_expect ((expr) ? 1 : 0, 0)
72#define ecb_expect_true(expr) ecb_expect ((expr) ? 1 : 0, 1)
73
74// try to tell the compiler that some condition is definitely true 459/* try to tell the compiler that some condition is definitely true */
75#define ecb_assume(cond) do { if (!(cond)) unreachable (); } while (0) 460#define ecb_assume(cond) do { if (!(cond)) ecb_unreachable (); } while (0)
76 461
77// count trailing zero bits and count # of one bits 462ecb_inline unsigned char ecb_byteorder_helper (void) ecb_const;
78#if ECB_GCC_VERSION(3,4) 463ecb_inline unsigned char
79static inline int ecb_ctz (unsigned int x) { return __builtin_ctz (x); } 464ecb_byteorder_helper (void)
80static inline int ecb_popcount (unsigned int x) { return __builtin_popcount (x); }
81#else
82static int ecb_ctz (unsigned int x) ecb_const
83{ 465{
84 int r = 0; 466 const uint32_t u = 0x11223344;
85 467 return *(unsigned char *)&u;
86 x &= -x; // this isolates the lowest bit
87
88 if (x & 0xaaaaaaaa) r += 1;
89 if (x & 0xcccccccc) r += 2;
90 if (x & 0xf0f0f0f0) r += 4;
91 if (x & 0xff00ff00) r += 8;
92 if (x & 0xffff0000) r += 16;
93
94 return r;
95} 468}
96 469
97static int ecb_popcount (unsigned int x) ecb_const 470ecb_inline ecb_bool ecb_big_endian (void) ecb_const;
98{ 471ecb_inline ecb_bool ecb_big_endian (void) { return ecb_byteorder_helper () == 0x11; }
99 x -= (x >> 1) & 0x55555555; 472ecb_inline ecb_bool ecb_little_endian (void) ecb_const;
100 x = ((x >> 2) & 0x33333333) + (x & 0x33333333); 473ecb_inline ecb_bool ecb_little_endian (void) { return ecb_byteorder_helper () == 0x44; }
101 x = ((x >> 4) + x) & 0x0f0f0f0f;
102 x *= 0x01010101;
103 474
104 return x >> 24; 475#if ECB_GCC_VERSION(3,0) || ECB_C99
105} 476 #define ecb_mod(m,n) ((m) % (n) + ((m) % (n) < 0 ? (n) : 0))
477#else
478 #define ecb_mod(m,n) ((m) < 0 ? ((n) - 1 - ((-1 - (m)) % (n))) : ((m) % (n)))
106#endif 479#endif
107 480
481#if __cplusplus
482 template<typename T>
483 static inline T ecb_div_rd (T val, T div)
484 {
485 return val < 0 ? - ((-val + div - 1) / div) : (val ) / div;
486 }
487 template<typename T>
488 static inline T ecb_div_ru (T val, T div)
489 {
490 return val < 0 ? - ((-val ) / div) : (val + div - 1) / div;
491 }
492#else
493 #define ecb_div_rd(val,div) ((val) < 0 ? - ((-(val) + (div) - 1) / (div)) : ((val) ) / (div))
494 #define ecb_div_ru(val,div) ((val) < 0 ? - ((-(val) ) / (div)) : ((val) + (div) - 1) / (div))
108#endif 495#endif
109 496
497#if ecb_cplusplus_does_not_suck
498 /* does not work for local types (http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2657.htm) */
499 template<typename T, int N>
500 static inline int ecb_array_length (const T (&arr)[N])
501 {
502 return N;
503 }
504#else
505 #define ecb_array_length(name) (sizeof (name) / sizeof (name [0]))
506#endif
507
508#endif
509

Diff Legend

– Removed lines
+ Added lines
< Changed lines
> Changed lines