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Comparing libecb/ecb.h (file contents):
Revision 1.1 by root, Thu May 26 16:41:12 2011 UTC vs.
Revision 1.109 by root, Fri Jun 29 14:05:50 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#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
32#define ECB_GCC_VERSION(major,minor) (__GNUC__ > (major) || (__GNUC__ == (major) && __GNUC_MINOR__ >= (minor))) 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 /*#elif defined __clang && __has_feature (cxx_atomic)*/
154 /* see comment below (stdatomic.h) about the C11 memory model. */
155 /*#define ECB_MEMORY_FENCE __c11_atomic_thread_fence (__ATOMIC_SEQ_CST)*/
156 #elif ECB_GCC_VERSION(4,4) || defined __INTEL_COMPILER || defined __clang__
157 #define ECB_MEMORY_FENCE __sync_synchronize ()
158 #elif _MSC_VER >= 1400 /* VC++ 2005 */
159 #pragma intrinsic(_ReadBarrier,_WriteBarrier,_ReadWriteBarrier)
160 #define ECB_MEMORY_FENCE _ReadWriteBarrier ()
161 #define ECB_MEMORY_FENCE_ACQUIRE _ReadWriteBarrier () /* according to msdn, _ReadBarrier is not a load fence */
162 #define ECB_MEMORY_FENCE_RELEASE _WriteBarrier ()
163 #elif defined _WIN32
164 #include <WinNT.h>
165 #define ECB_MEMORY_FENCE MemoryBarrier () /* actually just xchg on x86... scary */
166 #elif __SUNPRO_C >= 0x5110 || __SUNPRO_CC >= 0x5110
167 #include <mbarrier.h>
168 #define ECB_MEMORY_FENCE __machine_rw_barrier ()
169 #define ECB_MEMORY_FENCE_ACQUIRE __machine_r_barrier ()
170 #define ECB_MEMORY_FENCE_RELEASE __machine_w_barrier ()
171 #elif __xlC__
172 #define ECB_MEMORY_FENCE __sync ()
173 #endif
174#endif
175
176#ifndef ECB_MEMORY_FENCE
177 #if ECB_C11 && !defined __STDC_NO_ATOMICS__
178 /* we assume that these memory fences work on all variables/all memory accesses, */
179 /* not just C11 atomics and atomic accesses */
180 #include <stdatomic.h>
181 /* Unfortunately, neither gcc 4.7 nor clang 3.1 generate any instructions for */
182 /* any fence other than seq_cst, which isn't very efficient for us. */
183 /* Why that is, we don't know - either the C11 memory model is quite useless */
184 /* for most usages, or gcc and clang have a bug */
185 /* I *currently* lean towards the latter, and inefficiently implement */
186 /* all three of ecb's fences as a seq_cst fence */
187 #define ECB_MEMORY_FENCE atomic_thread_fence (memory_order_seq_cst)
188 #endif
189#endif
190
191#ifndef ECB_MEMORY_FENCE
192 #if !ECB_AVOID_PTHREADS
193 /*
194 * if you get undefined symbol references to pthread_mutex_lock,
195 * or failure to find pthread.h, then you should implement
196 * the ECB_MEMORY_FENCE operations for your cpu/compiler
197 * OR provide pthread.h and link against the posix thread library
198 * of your system.
199 */
200 #include <pthread.h>
201 #define ECB_NEEDS_PTHREADS 1
202 #define ECB_MEMORY_FENCE_NEEDS_PTHREADS 1
203
204 static pthread_mutex_t ecb_mf_lock = PTHREAD_MUTEX_INITIALIZER;
205 #define ECB_MEMORY_FENCE do { pthread_mutex_lock (&ecb_mf_lock); pthread_mutex_unlock (&ecb_mf_lock); } while (0)
206 #endif
207#endif
208
209#if !defined ECB_MEMORY_FENCE_ACQUIRE && defined ECB_MEMORY_FENCE
210 #define ECB_MEMORY_FENCE_ACQUIRE ECB_MEMORY_FENCE
211#endif
212
213#if !defined ECB_MEMORY_FENCE_RELEASE && defined ECB_MEMORY_FENCE
214 #define ECB_MEMORY_FENCE_RELEASE ECB_MEMORY_FENCE
215#endif
216
217/*****************************************************************************/
218
219#if __cplusplus
220 #define ecb_inline static inline
221#elif ECB_GCC_VERSION(2,5)
222 #define ecb_inline static __inline__
223#elif ECB_C99
224 #define ecb_inline static inline
225#else
226 #define ecb_inline static
227#endif
228
229#if ECB_GCC_VERSION(3,3)
230 #define ecb_restrict __restrict__
231#elif ECB_C99
232 #define ecb_restrict restrict
233#else
234 #define ecb_restrict
235#endif
236
237typedef int ecb_bool;
238
239#define ECB_CONCAT_(a, b) a ## b
240#define ECB_CONCAT(a, b) ECB_CONCAT_(a, b)
241#define ECB_STRINGIFY_(a) # a
242#define ECB_STRINGIFY(a) ECB_STRINGIFY_(a)
243
244#define ecb_function_ ecb_inline
33 245
34#if ECB_GCC_VERSION(3,1) 246#if ECB_GCC_VERSION(3,1)
35# define ecb_attribute(attrlist) __attribute__(attrlist) 247 #define ecb_attribute(attrlist) __attribute__(attrlist)
36# define ecb_is_constant(c) __builtin_constant_p (c) 248 #define ecb_is_constant(expr) __builtin_constant_p (expr)
37# define ecb_expect(expr,value) __builtin_expect ((expr),(value)) 249 #define ecb_expect(expr,value) __builtin_expect ((expr),(value))
38# define ecb_prefetch(addr,rw,locality) __builtin_prefetch (addr, rw, locality) 250 #define ecb_prefetch(addr,rw,locality) __builtin_prefetch (addr, rw, locality)
39#else 251#else
40# define ecb_attribute(attrlist) 252 #define ecb_attribute(attrlist)
41# define ecb_is_constant(c) 0 253 #define ecb_is_constant(expr) 0
42# define ecb_expect(expr,value) (expr) 254 #define ecb_expect(expr,value) (expr)
43# define ecb_prefetch(addr,rw,locality) 255 #define ecb_prefetch(addr,rw,locality)
44#endif 256#endif
45 257
258/* no emulation for ecb_decltype */
46#if ECB_GCC_VERSION(4,5) 259#if ECB_GCC_VERSION(4,5)
47# define ecb_decltype(x) __decltype(x) 260 #define ecb_decltype(x) __decltype(x)
48#elif ECB_GCC_VERSION(3,0) 261#elif ECB_GCC_VERSION(3,0)
49# define ecb_decltype(x) typeof(x) 262 #define ecb_decltype(x) __typeof(x)
50#endif 263#endif
51 264
52#define ecb_noinline ecb_attribute ((noinline)) 265#define ecb_noinline ecb_attribute ((__noinline__))
53#define ecb_noreturn ecb_attribute ((noreturn))
54#define ecb_unused ecb_attribute ((unused)) 266#define ecb_unused ecb_attribute ((__unused__))
55#define ecb_const ecb_attribute ((const)) 267#define ecb_const ecb_attribute ((__const__))
56#define ecb_pure ecb_attribute ((pure)) 268#define ecb_pure ecb_attribute ((__pure__))
269
270#if ECB_C11
271 #define ecb_noreturn _Noreturn
272#else
273 #define ecb_noreturn ecb_attribute ((__noreturn__))
274#endif
275
276#if ECB_GCC_VERSION(4,3)
277 #define ecb_artificial ecb_attribute ((__artificial__))
57#define ecb_hot ecb_attribute ((hot)) // 4.3 278 #define ecb_hot ecb_attribute ((__hot__))
58#define ecb_cold ecb_attribute ((cold)) // 4.3 279 #define ecb_cold ecb_attribute ((__cold__))
280#else
281 #define ecb_artificial
282 #define ecb_hot
283 #define ecb_cold
284#endif
285
286/* put around conditional expressions if you are very sure that the */
287/* expression is mostly true or mostly false. note that these return */
288/* booleans, not the expression. */
289#define ecb_expect_false(expr) ecb_expect (!!(expr), 0)
290#define ecb_expect_true(expr) ecb_expect (!!(expr), 1)
291/* for compatibility to the rest of the world */
292#define ecb_likely(expr) ecb_expect_true (expr)
293#define ecb_unlikely(expr) ecb_expect_false (expr)
294
295/* count trailing zero bits and count # of one bits */
296#if ECB_GCC_VERSION(3,4)
297 /* we assume int == 32 bit, long == 32 or 64 bit and long long == 64 bit */
298 #define ecb_ld32(x) (__builtin_clz (x) ^ 31)
299 #define ecb_ld64(x) (__builtin_clzll (x) ^ 63)
300 #define ecb_ctz32(x) __builtin_ctz (x)
301 #define ecb_ctz64(x) __builtin_ctzll (x)
302 #define ecb_popcount32(x) __builtin_popcount (x)
303 /* no popcountll */
304#else
305 ecb_function_ int ecb_ctz32 (uint32_t x) ecb_const;
306 ecb_function_ int
307 ecb_ctz32 (uint32_t x)
308 {
309 int r = 0;
310
311 x &= ~x + 1; /* this isolates the lowest bit */
312
313#if ECB_branchless_on_i386
314 r += !!(x & 0xaaaaaaaa) << 0;
315 r += !!(x & 0xcccccccc) << 1;
316 r += !!(x & 0xf0f0f0f0) << 2;
317 r += !!(x & 0xff00ff00) << 3;
318 r += !!(x & 0xffff0000) << 4;
319#else
320 if (x & 0xaaaaaaaa) r += 1;
321 if (x & 0xcccccccc) r += 2;
322 if (x & 0xf0f0f0f0) r += 4;
323 if (x & 0xff00ff00) r += 8;
324 if (x & 0xffff0000) r += 16;
325#endif
326
327 return r;
328 }
329
330 ecb_function_ int ecb_ctz64 (uint64_t x) ecb_const;
331 ecb_function_ int
332 ecb_ctz64 (uint64_t x)
333 {
334 int shift = x & 0xffffffffU ? 0 : 32;
335 return ecb_ctz32 (x >> shift) + shift;
336 }
337
338 ecb_function_ int ecb_popcount32 (uint32_t x) ecb_const;
339 ecb_function_ int
340 ecb_popcount32 (uint32_t x)
341 {
342 x -= (x >> 1) & 0x55555555;
343 x = ((x >> 2) & 0x33333333) + (x & 0x33333333);
344 x = ((x >> 4) + x) & 0x0f0f0f0f;
345 x *= 0x01010101;
346
347 return x >> 24;
348 }
349
350 ecb_function_ int ecb_ld32 (uint32_t x) ecb_const;
351 ecb_function_ int ecb_ld32 (uint32_t x)
352 {
353 int r = 0;
354
355 if (x >> 16) { x >>= 16; r += 16; }
356 if (x >> 8) { x >>= 8; r += 8; }
357 if (x >> 4) { x >>= 4; r += 4; }
358 if (x >> 2) { x >>= 2; r += 2; }
359 if (x >> 1) { r += 1; }
360
361 return r;
362 }
363
364 ecb_function_ int ecb_ld64 (uint64_t x) ecb_const;
365 ecb_function_ int ecb_ld64 (uint64_t x)
366 {
367 int r = 0;
368
369 if (x >> 32) { x >>= 32; r += 32; }
370
371 return r + ecb_ld32 (x);
372 }
373#endif
374
375ecb_function_ ecb_bool ecb_is_pot32 (uint32_t x) ecb_const;
376ecb_function_ ecb_bool ecb_is_pot32 (uint32_t x) { return !(x & (x - 1)); }
377ecb_function_ ecb_bool ecb_is_pot64 (uint64_t x) ecb_const;
378ecb_function_ ecb_bool ecb_is_pot64 (uint64_t x) { return !(x & (x - 1)); }
379
380ecb_function_ uint8_t ecb_bitrev8 (uint8_t x) ecb_const;
381ecb_function_ uint8_t ecb_bitrev8 (uint8_t x)
382{
383 return ( (x * 0x0802U & 0x22110U)
384 | (x * 0x8020U & 0x88440U)) * 0x10101U >> 16;
385}
386
387ecb_function_ uint16_t ecb_bitrev16 (uint16_t x) ecb_const;
388ecb_function_ uint16_t ecb_bitrev16 (uint16_t x)
389{
390 x = ((x >> 1) & 0x5555) | ((x & 0x5555) << 1);
391 x = ((x >> 2) & 0x3333) | ((x & 0x3333) << 2);
392 x = ((x >> 4) & 0x0f0f) | ((x & 0x0f0f) << 4);
393 x = ( x >> 8 ) | ( x << 8);
394
395 return x;
396}
397
398ecb_function_ uint32_t ecb_bitrev32 (uint32_t x) ecb_const;
399ecb_function_ uint32_t ecb_bitrev32 (uint32_t x)
400{
401 x = ((x >> 1) & 0x55555555) | ((x & 0x55555555) << 1);
402 x = ((x >> 2) & 0x33333333) | ((x & 0x33333333) << 2);
403 x = ((x >> 4) & 0x0f0f0f0f) | ((x & 0x0f0f0f0f) << 4);
404 x = ((x >> 8) & 0x00ff00ff) | ((x & 0x00ff00ff) << 8);
405 x = ( x >> 16 ) | ( x << 16);
406
407 return x;
408}
409
410/* popcount64 is only available on 64 bit cpus as gcc builtin */
411/* so for this version we are lazy */
412ecb_function_ int ecb_popcount64 (uint64_t x) ecb_const;
413ecb_function_ int
414ecb_popcount64 (uint64_t x)
415{
416 return ecb_popcount32 (x) + ecb_popcount32 (x >> 32);
417}
418
419ecb_inline uint8_t ecb_rotl8 (uint8_t x, unsigned int count) ecb_const;
420ecb_inline uint8_t ecb_rotr8 (uint8_t x, unsigned int count) ecb_const;
421ecb_inline uint16_t ecb_rotl16 (uint16_t x, unsigned int count) ecb_const;
422ecb_inline uint16_t ecb_rotr16 (uint16_t x, unsigned int count) ecb_const;
423ecb_inline uint32_t ecb_rotl32 (uint32_t x, unsigned int count) ecb_const;
424ecb_inline uint32_t ecb_rotr32 (uint32_t x, unsigned int count) ecb_const;
425ecb_inline uint64_t ecb_rotl64 (uint64_t x, unsigned int count) ecb_const;
426ecb_inline uint64_t ecb_rotr64 (uint64_t x, unsigned int count) ecb_const;
427
428ecb_inline uint8_t ecb_rotl8 (uint8_t x, unsigned int count) { return (x >> ( 8 - count)) | (x << count); }
429ecb_inline uint8_t ecb_rotr8 (uint8_t x, unsigned int count) { return (x << ( 8 - count)) | (x >> count); }
430ecb_inline uint16_t ecb_rotl16 (uint16_t x, unsigned int count) { return (x >> (16 - count)) | (x << count); }
431ecb_inline uint16_t ecb_rotr16 (uint16_t x, unsigned int count) { return (x << (16 - count)) | (x >> count); }
432ecb_inline uint32_t ecb_rotl32 (uint32_t x, unsigned int count) { return (x >> (32 - count)) | (x << count); }
433ecb_inline uint32_t ecb_rotr32 (uint32_t x, unsigned int count) { return (x << (32 - count)) | (x >> count); }
434ecb_inline uint64_t ecb_rotl64 (uint64_t x, unsigned int count) { return (x >> (64 - count)) | (x << count); }
435ecb_inline uint64_t ecb_rotr64 (uint64_t x, unsigned int count) { return (x << (64 - count)) | (x >> count); }
436
437#if ECB_GCC_VERSION(4,3)
438 #define ecb_bswap16(x) (__builtin_bswap32 (x) >> 16)
439 #define ecb_bswap32(x) __builtin_bswap32 (x)
440 #define ecb_bswap64(x) __builtin_bswap64 (x)
441#else
442 ecb_function_ uint16_t ecb_bswap16 (uint16_t x) ecb_const;
443 ecb_function_ uint16_t
444 ecb_bswap16 (uint16_t x)
445 {
446 return ecb_rotl16 (x, 8);
447 }
448
449 ecb_function_ uint32_t ecb_bswap32 (uint32_t x) ecb_const;
450 ecb_function_ uint32_t
451 ecb_bswap32 (uint32_t x)
452 {
453 return (((uint32_t)ecb_bswap16 (x)) << 16) | ecb_bswap16 (x >> 16);
454 }
455
456 ecb_function_ uint64_t ecb_bswap64 (uint64_t x) ecb_const;
457 ecb_function_ uint64_t
458 ecb_bswap64 (uint64_t x)
459 {
460 return (((uint64_t)ecb_bswap32 (x)) << 32) | ecb_bswap32 (x >> 32);
461 }
462#endif
59 463
60#if ECB_GCC_VERSION(4,5) 464#if ECB_GCC_VERSION(4,5)
61# define ecb_unreachable() __builtin_unreachable () 465 #define ecb_unreachable() __builtin_unreachable ()
62#else 466#else
63 // this seems to work fine, but gcc always emits a warning for it :/ 467 /* this seems to work fine, but gcc always emits a warning for it :/ */
64 static inline void ecb_unreachable () ecb_attribute ((noreturn)); 468 ecb_inline void ecb_unreachable (void) ecb_noreturn;
65 static inline void ecb_unreachable () { } 469 ecb_inline void ecb_unreachable (void) { }
66#endif 470#endif
67 471
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 472/* try to tell the compiler that some condition is definitely true */
75#define ecb_assume(cond) do { if (!(cond)) unreachable (); } while (0) 473#define ecb_assume(cond) if (!(cond)) ecb_unreachable (); else 0
76 474
77// count trailing zero bits and count # of one bits 475ecb_inline unsigned char ecb_byteorder_helper (void) ecb_const;
78#if ECB_GCC_VERSION(3,4) 476ecb_inline unsigned char
79static inline int ecb_ctz (unsigned int x) { return __builtin_ctz (x); } 477ecb_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{ 478{
84 int r = 0; 479 /* the union code still generates code under pressure in gcc, */
85 480 /* but less than using pointers, and always seem to */
86 x &= -x; // this isolates the lowest bit 481 /* successfully return a constant. */
87 482 /* the reason why we have this horrible preprocessor mess */
88 if (x & 0xaaaaaaaa) r += 1; 483 /* is to avoid it in all cases, at least on common architectures */
89 if (x & 0xcccccccc) r += 2; 484 /* and yes, gcc defines __BYTE_ORDER__, g++ does not */
90 if (x & 0xf0f0f0f0) r += 4; 485#if __i386 || __i386__ || _M_X86 || __amd64 || __amd64__ || _M_X64
91 if (x & 0xff00ff00) r += 8; 486 return 0x44;
92 if (x & 0xffff0000) r += 16; 487#elif __BYTE_ORDER__ && __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
93 488 return 0x44;
489#elif __BYTE_ORDER__ && __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
490 retrurn 0x11;
491#else
492 union
493 {
494 uint32_t i;
495 uint8_t c;
496 } u = { 0x11223344 };
94 return r; 497 return u.c;
498#endif
95} 499}
96 500
97static int ecb_popcount (unsigned int x) ecb_const 501ecb_inline ecb_bool ecb_big_endian (void) ecb_const;
98{ 502ecb_inline ecb_bool ecb_big_endian (void) { return ecb_byteorder_helper () == 0x11; }
99 x -= (x >> 1) & 0x55555555; 503ecb_inline ecb_bool ecb_little_endian (void) ecb_const;
100 x = ((x >> 2) & 0x33333333) + (x & 0x33333333); 504ecb_inline ecb_bool ecb_little_endian (void) { return ecb_byteorder_helper () == 0x44; }
101 x = ((x >> 4) + x) & 0x0f0f0f0f;
102 x *= 0x01010101;
103 505
104 return x >> 24; 506#if ECB_GCC_VERSION(3,0) || ECB_C99
105} 507 #define ecb_mod(m,n) ((m) % (n) + ((m) % (n) < 0 ? (n) : 0))
508#else
509 #define ecb_mod(m,n) ((m) < 0 ? ((n) - 1 - ((-1 - (m)) % (n))) : ((m) % (n)))
510#endif
511
512#if __cplusplus
513 template<typename T>
514 static inline T ecb_div_rd (T val, T div)
515 {
516 return val < 0 ? - ((-val + div - 1) / div) : (val ) / div;
517 }
518 template<typename T>
519 static inline T ecb_div_ru (T val, T div)
520 {
521 return val < 0 ? - ((-val ) / div) : (val + div - 1) / div;
522 }
523#else
524 #define ecb_div_rd(val,div) ((val) < 0 ? - ((-(val) + (div) - 1) / (div)) : ((val) ) / (div))
525 #define ecb_div_ru(val,div) ((val) < 0 ? - ((-(val) ) / (div)) : ((val) + (div) - 1) / (div))
526#endif
527
528#if ecb_cplusplus_does_not_suck
529 /* does not work for local types (http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2657.htm) */
530 template<typename T, int N>
531 static inline int ecb_array_length (const T (&arr)[N])
532 {
533 return N;
534 }
535#else
536 #define ecb_array_length(name) (sizeof (name) / sizeof (name [0]))
537#endif
538
539/*******************************************************************************/
540/* floating point stuff, can be disabled by defining ECB_NO_LIBM */
541
542/* basically, everything uses "ieee pure-endian" floating point numbers */
543/* the only noteworthy exception is ancient armle, which uses order 43218765 */
544#if 0 \
545 || __i386 || __i386__ \
546 || __amd64 || __amd64__ || __x86_64 || __x86_64__ \
547 || __powerpc__ || __ppc__ || __powerpc64__ || __ppc64__ \
548 || defined __arm__ && defined __ARM_EABI__ \
549 || defined __s390__ || defined __s390x__ \
550 || defined __mips__ \
551 || defined __alpha__ \
552 || defined __hppa__ \
553 || defined __ia64__ \
554 || defined _M_IX86 || defined _M_AMD64 || defined _M_IA64
555 #define ECB_STDFP 1
556 #include <string.h> /* for memcpy */
557#else
558 #define ECB_STDFP 0
559 #include <math.h> /* for frexp*, ldexp* */
560#endif
561
562#ifndef ECB_NO_LIBM
563
564 /* convert a float to ieee single/binary32 */
565 ecb_function_ uint32_t ecb_float_to_binary32 (float x) ecb_const;
566 ecb_function_ uint32_t
567 ecb_float_to_binary32 (float x)
568 {
569 uint32_t r;
570
571 #if ECB_STDFP
572 memcpy (&r, &x, 4);
573 #else
574 /* slow emulation, works for anything but -0 */
575 uint32_t m;
576 int e;
577
578 if (x == 0e0f ) return 0x00000000U;
579 if (x > +3.40282346638528860e+38f) return 0x7f800000U;
580 if (x < -3.40282346638528860e+38f) return 0xff800000U;
581 if (x != x ) return 0x7fbfffffU;
582
583 m = frexpf (x, &e) * 0x1000000U;
584
585 r = m & 0x80000000U;
586
587 if (r)
588 m = -m;
589
590 if (e <= -126)
591 {
592 m &= 0xffffffU;
593 m >>= (-125 - e);
594 e = -126;
595 }
596
597 r |= (e + 126) << 23;
598 r |= m & 0x7fffffU;
106#endif 599 #endif
107 600
601 return r;
602 }
603
604 /* converts an ieee single/binary32 to a float */
605 ecb_function_ float ecb_binary32_to_float (uint32_t x) ecb_const;
606 ecb_function_ float
607 ecb_binary32_to_float (uint32_t x)
608 {
609 float r;
610
611 #if ECB_STDFP
612 memcpy (&r, &x, 4);
613 #else
614 /* emulation, only works for normals and subnormals and +0 */
615 int neg = x >> 31;
616 int e = (x >> 23) & 0xffU;
617
618 x &= 0x7fffffU;
619
620 if (e)
621 x |= 0x800000U;
622 else
623 e = 1;
624
625 /* we distrust ldexpf a bit and do the 2**-24 scaling by an extra multiply */
626 r = ldexpf (x * (0.5f / 0x800000U), e - 126);
627
628 r = neg ? -r : r;
108#endif 629 #endif
109 630
631 return r;
632 }
633
634 /* convert a double to ieee double/binary64 */
635 ecb_function_ uint64_t ecb_double_to_binary64 (double x) ecb_const;
636 ecb_function_ uint64_t
637 ecb_double_to_binary64 (double x)
638 {
639 uint64_t r;
640
641 #if ECB_STDFP
642 memcpy (&r, &x, 8);
643 #else
644 /* slow emulation, works for anything but -0 */
645 uint64_t m;
646 int e;
647
648 if (x == 0e0 ) return 0x0000000000000000U;
649 if (x > +1.79769313486231470e+308) return 0x7ff0000000000000U;
650 if (x < -1.79769313486231470e+308) return 0xfff0000000000000U;
651 if (x != x ) return 0X7ff7ffffffffffffU;
652
653 m = frexp (x, &e) * 0x20000000000000U;
654
655 r = m & 0x8000000000000000;;
656
657 if (r)
658 m = -m;
659
660 if (e <= -1022)
661 {
662 m &= 0x1fffffffffffffU;
663 m >>= (-1021 - e);
664 e = -1022;
665 }
666
667 r |= ((uint64_t)(e + 1022)) << 52;
668 r |= m & 0xfffffffffffffU;
669 #endif
670
671 return r;
672 }
673
674 /* converts an ieee double/binary64 to a double */
675 ecb_function_ double ecb_binary64_to_double (uint64_t x) ecb_const;
676 ecb_function_ double
677 ecb_binary64_to_double (uint64_t x)
678 {
679 double r;
680
681 #if ECB_STDFP
682 memcpy (&r, &x, 8);
683 #else
684 /* emulation, only works for normals and subnormals and +0 */
685 int neg = x >> 63;
686 int e = (x >> 52) & 0x7ffU;
687
688 x &= 0xfffffffffffffU;
689
690 if (e)
691 x |= 0x10000000000000U;
692 else
693 e = 1;
694
695 /* we distrust ldexp a bit and do the 2**-53 scaling by an extra multiply */
696 r = ldexp (x * (0.5 / 0x10000000000000U), e - 1022);
697
698 r = neg ? -r : r;
699 #endif
700
701 return r;
702 }
703
704#endif
705
706#endif
707

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