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Comparing libeio/ecb.h (file contents):
Revision 1.7 by root, Wed Aug 3 15:25:38 2011 UTC vs.
Revision 1.19 by root, Fri Jan 24 23:46:17 2014 UTC

1/* 1/*
2 * libecb - http://software.schmorp.de/pkg/libecb 2 * libecb - http://software.schmorp.de/pkg/libecb
3 * 3 *
4 * Copyright (©) 2009-2011 Marc Alexander Lehmann <libecb@schmorp.de> 4 * Copyright (©) 2009-2013 Marc Alexander Lehmann <libecb@schmorp.de>
5 * Copyright (©) 2011 Emanuele Giaquinta 5 * Copyright (©) 2011 Emanuele Giaquinta
6 * All rights reserved. 6 * All rights reserved.
7 * 7 *
8 * 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-
9 * tion, are permitted provided that the following conditions are met: 9 * tion, are permitted provided that the following conditions are met:
28 */ 28 */
29 29
30#ifndef ECB_H 30#ifndef ECB_H
31#define ECB_H 31#define ECB_H
32 32
33/* 16 bits major, 16 bits minor */
34#define ECB_VERSION 0x00010003
35
33#ifdef _WIN32 36#ifdef _WIN32
34 typedef signed char int8_t; 37 typedef signed char int8_t;
35 typedef unsigned char uint8_t; 38 typedef unsigned char uint8_t;
36 typedef signed short int16_t; 39 typedef signed short int16_t;
37 typedef unsigned short uint16_t; 40 typedef unsigned short uint16_t;
42 typedef unsigned long long uint64_t; 45 typedef unsigned long long uint64_t;
43 #else /* _MSC_VER || __BORLANDC__ */ 46 #else /* _MSC_VER || __BORLANDC__ */
44 typedef signed __int64 int64_t; 47 typedef signed __int64 int64_t;
45 typedef unsigned __int64 uint64_t; 48 typedef unsigned __int64 uint64_t;
46 #endif 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
47#else 59#else
48 #include <inttypes.h> 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/* work around x32 idiocy by defining proper macros */
69#if __amd64 || __x86_64 || _M_AMD64 || _M_X64
70 #if _ILP32
71 #define ECB_AMD64_X32 1
72 #else
73 #define ECB_AMD64 1
74 #endif
49#endif 75#endif
50 76
51/* many compilers define _GNUC_ to some versions but then only implement 77/* many compilers define _GNUC_ to some versions but then only implement
52 * what their idiot authors think are the "more important" extensions, 78 * what their idiot authors think are the "more important" extensions,
53 * causing enourmous grief in return for some better fake benchmark numbers. 79 * causing enormous grief in return for some better fake benchmark numbers.
54 * or so. 80 * or so.
55 * we try to detect these and simply assume they are not gcc - if they have 81 * we try to detect these and simply assume they are not gcc - if they have
56 * an issue with that they should have done it right in the first place. 82 * an issue with that they should have done it right in the first place.
57 */ 83 */
58#ifndef ECB_GCC_VERSION 84#ifndef ECB_GCC_VERSION
59 #if !defined(__GNUC_MINOR__) || defined(__INTEL_COMPILER) || defined(__SUNPRO_C) || defined(__SUNPRO_CC) || defined(__llvm__) || defined(__clang__) 85 #if !defined __GNUC_MINOR__ || defined __INTEL_COMPILER || defined __SUNPRO_C || defined __SUNPRO_CC || defined __llvm__ || defined __clang__
60 #define ECB_GCC_VERSION(major,minor) 0 86 #define ECB_GCC_VERSION(major,minor) 0
61 #else 87 #else
62 #define ECB_GCC_VERSION(major,minor) (__GNUC__ > (major) || (__GNUC__ == (major) && __GNUC_MINOR__ >= (minor))) 88 #define ECB_GCC_VERSION(major,minor) (__GNUC__ > (major) || (__GNUC__ == (major) && __GNUC_MINOR__ >= (minor)))
63 #endif 89 #endif
64#endif 90#endif
65 91
92#define ECB_CPP (__cplusplus+0)
93#define ECB_CPP11 (__cplusplus >= 201103L)
94
95#if ECB_CPP
96 #define ECB_C 0
97 #define ECB_STDC_VERSION 0
98#else
99 #define ECB_C 1
100 #define ECB_STDC_VERSION __STDC_VERSION__
101#endif
102
103#define ECB_C99 (ECB_STDC_VERSION >= 199901L)
104#define ECB_C11 (ECB_STDC_VERSION >= 201112L)
105
106#if ECB_CPP
107 #define ECB_EXTERN_C extern "C"
108 #define ECB_EXTERN_C_BEG ECB_EXTERN_C {
109 #define ECB_EXTERN_C_END }
110#else
111 #define ECB_EXTERN_C extern
112 #define ECB_EXTERN_C_BEG
113 #define ECB_EXTERN_C_END
114#endif
115
66/*****************************************************************************/ 116/*****************************************************************************/
67 117
118/* ECB_NO_THREADS - ecb is not used by multiple threads, ever */
119/* ECB_NO_SMP - ecb might be used in multiple threads, but only on a single cpu */
120
121#if ECB_NO_THREADS
122 #define ECB_NO_SMP 1
123#endif
124
125#if ECB_NO_SMP
126 #define ECB_MEMORY_FENCE do { } while (0)
127#endif
128
68#ifndef ECB_MEMORY_FENCE 129#ifndef ECB_MEMORY_FENCE
69 #if ECB_GCC_VERSION(2,5) 130 #if ECB_GCC_VERSION(2,5) || defined __INTEL_COMPILER || (__llvm__ && __GNUC__) || __SUNPRO_C >= 0x5110 || __SUNPRO_CC >= 0x5110
70 #if __x86 131 #if __i386 || __i386__
71 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("lock; orb $0, -1(%%esp)" : : : "memory") 132 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("lock; orb $0, -1(%%esp)" : : : "memory")
72 #define ECB_MEMORY_FENCE_ACQUIRE ECB_MEMORY_FENCE /* non-lock xchg might be enough */ 133 #define ECB_MEMORY_FENCE_ACQUIRE __asm__ __volatile__ ("" : : : "memory")
73 #define ECB_MEMORY_FENCE_RELEASE do { } while (0) /* unlikely to change in future cpus */ 134 #define ECB_MEMORY_FENCE_RELEASE __asm__ __volatile__ ("")
74 #elif __amd64 135 #elif __amd64 || __amd64__ || __x86_64 || __x86_64__
75 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("mfence" : : : "memory") 136 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("mfence" : : : "memory")
76 #define ECB_MEMORY_FENCE_ACQUIRE __asm__ __volatile__ ("lfence" : : : "memory") 137 #define ECB_MEMORY_FENCE_ACQUIRE __asm__ __volatile__ ("" : : : "memory")
77 #define ECB_MEMORY_FENCE_RELEASE __asm__ __volatile__ ("sfence") /* play safe - not needed in any current cpu */ 138 #define ECB_MEMORY_FENCE_RELEASE __asm__ __volatile__ ("")
139 #elif __powerpc__ || __ppc__ || __powerpc64__ || __ppc64__
140 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("sync" : : : "memory")
141 #elif defined __ARM_ARCH_6__ || defined __ARM_ARCH_6J__ \
142 || defined __ARM_ARCH_6K__ || defined __ARM_ARCH_6ZK__
143 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("mcr p15,0,%0,c7,c10,5" : : "r" (0) : "memory")
144 #elif defined __ARM_ARCH_7__ || defined __ARM_ARCH_7A__ \
145 || defined __ARM_ARCH_7M__ || defined __ARM_ARCH_7R__
146 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("dmb" : : : "memory")
147 #elif (__sparc || __sparc__) && !__sparcv8
148 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("membar #LoadStore | #LoadLoad | #StoreStore | #StoreLoad" : : : "memory")
149 #define ECB_MEMORY_FENCE_ACQUIRE __asm__ __volatile__ ("membar #LoadStore | #LoadLoad" : : : "memory")
150 #define ECB_MEMORY_FENCE_RELEASE __asm__ __volatile__ ("membar #LoadStore | #StoreStore")
151 #elif defined __s390__ || defined __s390x__
152 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("bcr 15,0" : : : "memory")
153 #elif defined __mips__
154 /* GNU/Linux emulates sync on mips1 architectures, so we force its use */
155 /* anybody else who still uses mips1 is supposed to send in their version, with detection code. */
156 #define ECB_MEMORY_FENCE __asm__ __volatile__ (".set mips2; sync; .set mips0" : : : "memory")
157 #elif defined __alpha__
158 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("mb" : : : "memory")
159 #elif defined __hppa__
160 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("" : : : "memory")
161 #define ECB_MEMORY_FENCE_RELEASE __asm__ __volatile__ ("")
162 #elif defined __ia64__
163 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("mf" : : : "memory")
164 #elif defined __m68k__
165 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("" : : : "memory")
166 #elif defined __m88k__
167 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("tb1 0,%%r0,128" : : : "memory")
168 #elif defined __sh__
169 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("" : : : "memory")
78 #endif 170 #endif
79 #endif 171 #endif
80#endif 172#endif
81 173
82#ifndef ECB_MEMORY_FENCE 174#ifndef ECB_MEMORY_FENCE
83 #if ECB_GCC_VERSION(4,4) 175 #if ECB_GCC_VERSION(4,7)
176 /* see comment below (stdatomic.h) about the C11 memory model. */
177 #define ECB_MEMORY_FENCE __atomic_thread_fence (__ATOMIC_SEQ_CST)
178 #define ECB_MEMORY_FENCE_ACQUIRE __atomic_thread_fence (__ATOMIC_ACQUIRE)
179 #define ECB_MEMORY_FENCE_RELEASE __atomic_thread_fence (__ATOMIC_RELEASE)
180
181 /* The __has_feature syntax from clang is so misdesigned that we cannot use it
182 * without risking compile time errors with other compilers. We *could*
183 * define our own ecb_clang_has_feature, but I just can't be bothered to work
184 * around this shit time and again.
185 * #elif defined __clang && __has_feature (cxx_atomic)
186 * // see comment below (stdatomic.h) about the C11 memory model.
187 * #define ECB_MEMORY_FENCE __c11_atomic_thread_fence (__ATOMIC_SEQ_CST)
188 * #define ECB_MEMORY_FENCE_ACQUIRE __c11_atomic_thread_fence (__ATOMIC_ACQUIRE)
189 * #define ECB_MEMORY_FENCE_RELEASE __c11_atomic_thread_fence (__ATOMIC_RELEASE)
190 */
191
192 #elif ECB_GCC_VERSION(4,4) || defined __INTEL_COMPILER || defined __clang__
84 #define ECB_MEMORY_FENCE __sync_synchronize () 193 #define ECB_MEMORY_FENCE __sync_synchronize ()
85 #define ECB_MEMORY_FENCE_ACQUIRE ({ char dummy = 0; __sync_lock_test_and_set (&dummy, 1); }) 194 #elif _MSC_VER >= 1500 /* VC++ 2008 */
86 #define ECB_MEMORY_FENCE_RELEASE ({ char dummy = 1; __sync_lock_release (&dummy ); }) 195 /* apparently, microsoft broke all the memory barrier stuff in Visual Studio 2008... */
196 #pragma intrinsic(_ReadBarrier,_WriteBarrier,_ReadWriteBarrier)
197 #define ECB_MEMORY_FENCE _ReadWriteBarrier (); MemoryBarrier()
198 #define ECB_MEMORY_FENCE_ACQUIRE _ReadWriteBarrier (); MemoryBarrier() /* according to msdn, _ReadBarrier is not a load fence */
199 #define ECB_MEMORY_FENCE_RELEASE _WriteBarrier (); MemoryBarrier()
87 #elif _MSC_VER >= 1400 /* VC++ 2005 */ 200 #elif _MSC_VER >= 1400 /* VC++ 2005 */
88 #pragma intrinsic(_ReadBarrier,_WriteBarrier,_ReadWriteBarrier) 201 #pragma intrinsic(_ReadBarrier,_WriteBarrier,_ReadWriteBarrier)
89 #define ECB_MEMORY_FENCE _ReadWriteBarrier () 202 #define ECB_MEMORY_FENCE _ReadWriteBarrier ()
90 #define ECB_MEMORY_FENCE_ACQUIRE _ReadWriteBarrier () /* according to msdn, _ReadBarrier is not a load fence */ 203 #define ECB_MEMORY_FENCE_ACQUIRE _ReadWriteBarrier () /* according to msdn, _ReadBarrier is not a load fence */
91 #define ECB_MEMORY_FENCE_RELEASE _WriteBarrier () 204 #define ECB_MEMORY_FENCE_RELEASE _WriteBarrier ()
92 #elif defined(_WIN32) 205 #elif defined _WIN32
93 #include <WinNT.h> 206 #include <WinNT.h>
94 #define ECB_MEMORY_FENCE MemoryBarrier () /* actually just xchg on x86... scary */ 207 #define ECB_MEMORY_FENCE MemoryBarrier () /* actually just xchg on x86... scary */
95 #define ECB_MEMORY_FENCE_ACQUIRE ECB_MEMORY_FENCE 208 #elif __SUNPRO_C >= 0x5110 || __SUNPRO_CC >= 0x5110
96 #define ECB_MEMORY_FENCE_RELEASE ECB_MEMORY_FENCE 209 #include <mbarrier.h>
210 #define ECB_MEMORY_FENCE __machine_rw_barrier ()
211 #define ECB_MEMORY_FENCE_ACQUIRE __machine_r_barrier ()
212 #define ECB_MEMORY_FENCE_RELEASE __machine_w_barrier ()
213 #elif __xlC__
214 #define ECB_MEMORY_FENCE __sync ()
97 #endif 215 #endif
98#endif 216#endif
99 217
100#ifndef ECB_MEMORY_FENCE 218#ifndef ECB_MEMORY_FENCE
219 #if ECB_C11 && !defined __STDC_NO_ATOMICS__
220 /* we assume that these memory fences work on all variables/all memory accesses, */
221 /* not just C11 atomics and atomic accesses */
222 #include <stdatomic.h>
223 /* Unfortunately, neither gcc 4.7 nor clang 3.1 generate any instructions for */
224 /* any fence other than seq_cst, which isn't very efficient for us. */
225 /* Why that is, we don't know - either the C11 memory model is quite useless */
226 /* for most usages, or gcc and clang have a bug */
227 /* I *currently* lean towards the latter, and inefficiently implement */
228 /* all three of ecb's fences as a seq_cst fence */
229 /* Update, gcc-4.8 generates mfence for all c++ fences, but nothing */
230 /* for all __atomic_thread_fence's except seq_cst */
231 #define ECB_MEMORY_FENCE atomic_thread_fence (memory_order_seq_cst)
232 #endif
233#endif
234
235#ifndef ECB_MEMORY_FENCE
236 #if !ECB_AVOID_PTHREADS
101 /* 237 /*
102 * if you get undefined symbol references to pthread_mutex_lock, 238 * if you get undefined symbol references to pthread_mutex_lock,
103 * or failure to find pthread.h, then you should implement 239 * or failure to find pthread.h, then you should implement
104 * the ECB_MEMORY_FENCE operations for your cpu/compiler 240 * the ECB_MEMORY_FENCE operations for your cpu/compiler
105 * OR proide pthread.h and link against the posix thread library 241 * OR provide pthread.h and link against the posix thread library
106 * of your system. 242 * of your system.
107 */ 243 */
108 #include <pthread.h> 244 #include <pthread.h>
245 #define ECB_NEEDS_PTHREADS 1
246 #define ECB_MEMORY_FENCE_NEEDS_PTHREADS 1
109 247
110 static pthread_mutex_t ecb_mf_lock = PTHREAD_MUTEX_INITIALIZER; 248 static pthread_mutex_t ecb_mf_lock = PTHREAD_MUTEX_INITIALIZER;
111 #define ECB_MEMORY_FENCE do { pthread_mutex_lock (&ecb_mf_lock); pthread_mutex_unlock (&ecb_mf_lock); } while (0) 249 #define ECB_MEMORY_FENCE do { pthread_mutex_lock (&ecb_mf_lock); pthread_mutex_unlock (&ecb_mf_lock); } while (0)
250 #endif
251#endif
252
253#if !defined ECB_MEMORY_FENCE_ACQUIRE && defined ECB_MEMORY_FENCE
112 #define ECB_MEMORY_FENCE_ACQUIRE ECB_MEMORY_FENCE 254 #define ECB_MEMORY_FENCE_ACQUIRE ECB_MEMORY_FENCE
255#endif
256
257#if !defined ECB_MEMORY_FENCE_RELEASE && defined ECB_MEMORY_FENCE
113 #define ECB_MEMORY_FENCE_RELEASE ECB_MEMORY_FENCE 258 #define ECB_MEMORY_FENCE_RELEASE ECB_MEMORY_FENCE
114#endif 259#endif
115 260
116/*****************************************************************************/ 261/*****************************************************************************/
117
118#define ECB_C99 (__STDC_VERSION__ >= 199901L)
119 262
120#if __cplusplus 263#if __cplusplus
121 #define ecb_inline static inline 264 #define ecb_inline static inline
122#elif ECB_GCC_VERSION(2,5) 265#elif ECB_GCC_VERSION(2,5)
123 #define ecb_inline static __inline__ 266 #define ecb_inline static __inline__
149 #define ecb_is_constant(expr) __builtin_constant_p (expr) 292 #define ecb_is_constant(expr) __builtin_constant_p (expr)
150 #define ecb_expect(expr,value) __builtin_expect ((expr),(value)) 293 #define ecb_expect(expr,value) __builtin_expect ((expr),(value))
151 #define ecb_prefetch(addr,rw,locality) __builtin_prefetch (addr, rw, locality) 294 #define ecb_prefetch(addr,rw,locality) __builtin_prefetch (addr, rw, locality)
152#else 295#else
153 #define ecb_attribute(attrlist) 296 #define ecb_attribute(attrlist)
297
298 /* possible C11 impl for integral types
299 typedef struct ecb_is_constant_struct ecb_is_constant_struct;
300 #define ecb_is_constant(expr) _Generic ((1 ? (struct ecb_is_constant_struct *)0 : (void *)((expr) - (expr)), ecb_is_constant_struct *: 0, default: 1)) */
301
154 #define ecb_is_constant(expr) 0 302 #define ecb_is_constant(expr) 0
155 #define ecb_expect(expr,value) (expr) 303 #define ecb_expect(expr,value) (expr)
156 #define ecb_prefetch(addr,rw,locality) 304 #define ecb_prefetch(addr,rw,locality)
157#endif 305#endif
158 306
162#elif ECB_GCC_VERSION(3,0) 310#elif ECB_GCC_VERSION(3,0)
163 #define ecb_decltype(x) __typeof(x) 311 #define ecb_decltype(x) __typeof(x)
164#endif 312#endif
165 313
166#define ecb_noinline ecb_attribute ((__noinline__)) 314#define ecb_noinline ecb_attribute ((__noinline__))
167#define ecb_noreturn ecb_attribute ((__noreturn__))
168#define ecb_unused ecb_attribute ((__unused__)) 315#define ecb_unused ecb_attribute ((__unused__))
169#define ecb_const ecb_attribute ((__const__)) 316#define ecb_const ecb_attribute ((__const__))
170#define ecb_pure ecb_attribute ((__pure__)) 317#define ecb_pure ecb_attribute ((__pure__))
318
319#if ECB_C11
320 #define ecb_noreturn _Noreturn
321#else
322 #define ecb_noreturn ecb_attribute ((__noreturn__))
323#endif
171 324
172#if ECB_GCC_VERSION(4,3) 325#if ECB_GCC_VERSION(4,3)
173 #define ecb_artificial ecb_attribute ((__artificial__)) 326 #define ecb_artificial ecb_attribute ((__artificial__))
174 #define ecb_hot ecb_attribute ((__hot__)) 327 #define ecb_hot ecb_attribute ((__hot__))
175 #define ecb_cold ecb_attribute ((__cold__)) 328 #define ecb_cold ecb_attribute ((__cold__))
241 x *= 0x01010101; 394 x *= 0x01010101;
242 395
243 return x >> 24; 396 return x >> 24;
244 } 397 }
245 398
246 /* you have the choice beetween something with a table lookup, */
247 /* something using lots of bit arithmetic and a simple loop */
248 /* we went for the loop */
249 ecb_function_ int ecb_ld32 (uint32_t x) ecb_const; 399 ecb_function_ int ecb_ld32 (uint32_t x) ecb_const;
250 ecb_function_ int ecb_ld32 (uint32_t x) 400 ecb_function_ int ecb_ld32 (uint32_t x)
251 { 401 {
252 int r = 0; 402 int r = 0;
253 403
268 if (x >> 32) { x >>= 32; r += 32; } 418 if (x >> 32) { x >>= 32; r += 32; }
269 419
270 return r + ecb_ld32 (x); 420 return r + ecb_ld32 (x);
271 } 421 }
272#endif 422#endif
423
424ecb_function_ ecb_bool ecb_is_pot32 (uint32_t x) ecb_const;
425ecb_function_ ecb_bool ecb_is_pot32 (uint32_t x) { return !(x & (x - 1)); }
426ecb_function_ ecb_bool ecb_is_pot64 (uint64_t x) ecb_const;
427ecb_function_ ecb_bool ecb_is_pot64 (uint64_t x) { return !(x & (x - 1)); }
428
429ecb_function_ uint8_t ecb_bitrev8 (uint8_t x) ecb_const;
430ecb_function_ uint8_t ecb_bitrev8 (uint8_t x)
431{
432 return ( (x * 0x0802U & 0x22110U)
433 | (x * 0x8020U & 0x88440U)) * 0x10101U >> 16;
434}
435
436ecb_function_ uint16_t ecb_bitrev16 (uint16_t x) ecb_const;
437ecb_function_ uint16_t ecb_bitrev16 (uint16_t x)
438{
439 x = ((x >> 1) & 0x5555) | ((x & 0x5555) << 1);
440 x = ((x >> 2) & 0x3333) | ((x & 0x3333) << 2);
441 x = ((x >> 4) & 0x0f0f) | ((x & 0x0f0f) << 4);
442 x = ( x >> 8 ) | ( x << 8);
443
444 return x;
445}
446
447ecb_function_ uint32_t ecb_bitrev32 (uint32_t x) ecb_const;
448ecb_function_ uint32_t ecb_bitrev32 (uint32_t x)
449{
450 x = ((x >> 1) & 0x55555555) | ((x & 0x55555555) << 1);
451 x = ((x >> 2) & 0x33333333) | ((x & 0x33333333) << 2);
452 x = ((x >> 4) & 0x0f0f0f0f) | ((x & 0x0f0f0f0f) << 4);
453 x = ((x >> 8) & 0x00ff00ff) | ((x & 0x00ff00ff) << 8);
454 x = ( x >> 16 ) | ( x << 16);
455
456 return x;
457}
273 458
274/* popcount64 is only available on 64 bit cpus as gcc builtin */ 459/* popcount64 is only available on 64 bit cpus as gcc builtin */
275/* so for this version we are lazy */ 460/* so for this version we are lazy */
276ecb_function_ int ecb_popcount64 (uint64_t x) ecb_const; 461ecb_function_ int ecb_popcount64 (uint64_t x) ecb_const;
277ecb_function_ int 462ecb_function_ int
327 512
328#if ECB_GCC_VERSION(4,5) 513#if ECB_GCC_VERSION(4,5)
329 #define ecb_unreachable() __builtin_unreachable () 514 #define ecb_unreachable() __builtin_unreachable ()
330#else 515#else
331 /* this seems to work fine, but gcc always emits a warning for it :/ */ 516 /* this seems to work fine, but gcc always emits a warning for it :/ */
332 ecb_function_ void ecb_unreachable (void) ecb_noreturn; 517 ecb_inline void ecb_unreachable (void) ecb_noreturn;
333 ecb_function_ void ecb_unreachable (void) { } 518 ecb_inline void ecb_unreachable (void) { }
334#endif 519#endif
335 520
336/* try to tell the compiler that some condition is definitely true */ 521/* try to tell the compiler that some condition is definitely true */
337#define ecb_assume(cond) do { if (!(cond)) ecb_unreachable (); } while (0) 522#define ecb_assume(cond) if (!(cond)) ecb_unreachable (); else 0
338 523
339ecb_function_ unsigned char ecb_byteorder_helper (void) ecb_const; 524ecb_inline unsigned char ecb_byteorder_helper (void) ecb_const;
340ecb_function_ unsigned char 525ecb_inline unsigned char
341ecb_byteorder_helper (void) 526ecb_byteorder_helper (void)
342{ 527{
343 const uint32_t u = 0x11223344; 528 /* the union code still generates code under pressure in gcc, */
344 return *(unsigned char *)&u; 529 /* but less than using pointers, and always seems to */
530 /* successfully return a constant. */
531 /* the reason why we have this horrible preprocessor mess */
532 /* is to avoid it in all cases, at least on common architectures */
533 /* or when using a recent enough gcc version (>= 4.6) */
534#if __i386 || __i386__ || _M_X86 || __amd64 || __amd64__ || _M_X64
535 return 0x44;
536#elif __BYTE_ORDER__ && __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
537 return 0x44;
538#elif __BYTE_ORDER__ && __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
539 return 0x11;
540#else
541 union
542 {
543 uint32_t i;
544 uint8_t c;
545 } u = { 0x11223344 };
546 return u.c;
547#endif
345} 548}
346 549
347ecb_function_ ecb_bool ecb_big_endian (void) ecb_const; 550ecb_inline ecb_bool ecb_big_endian (void) ecb_const;
348ecb_function_ ecb_bool ecb_big_endian (void) { return ecb_byteorder_helper () == 0x11; } 551ecb_inline ecb_bool ecb_big_endian (void) { return ecb_byteorder_helper () == 0x11; }
349ecb_function_ ecb_bool ecb_little_endian (void) ecb_const; 552ecb_inline ecb_bool ecb_little_endian (void) ecb_const;
350ecb_function_ ecb_bool ecb_little_endian (void) { return ecb_byteorder_helper () == 0x44; } 553ecb_inline ecb_bool ecb_little_endian (void) { return ecb_byteorder_helper () == 0x44; }
351 554
352#if ECB_GCC_VERSION(3,0) || ECB_C99 555#if ECB_GCC_VERSION(3,0) || ECB_C99
353 #define ecb_mod(m,n) ((m) % (n) + ((m) % (n) < 0 ? (n) : 0)) 556 #define ecb_mod(m,n) ((m) % (n) + ((m) % (n) < 0 ? (n) : 0))
354#else 557#else
355 #define ecb_mod(m,n) ((m) < 0 ? ((n) - 1 - ((-1 - (m)) % (n))) : ((m) % (n))) 558 #define ecb_mod(m,n) ((m) < 0 ? ((n) - 1 - ((-1 - (m)) % (n))) : ((m) % (n)))
559#endif
560
561#if __cplusplus
562 template<typename T>
563 static inline T ecb_div_rd (T val, T div)
564 {
565 return val < 0 ? - ((-val + div - 1) / div) : (val ) / div;
566 }
567 template<typename T>
568 static inline T ecb_div_ru (T val, T div)
569 {
570 return val < 0 ? - ((-val ) / div) : (val + div - 1) / div;
571 }
572#else
573 #define ecb_div_rd(val,div) ((val) < 0 ? - ((-(val) + (div) - 1) / (div)) : ((val) ) / (div))
574 #define ecb_div_ru(val,div) ((val) < 0 ? - ((-(val) ) / (div)) : ((val) + (div) - 1) / (div))
356#endif 575#endif
357 576
358#if ecb_cplusplus_does_not_suck 577#if ecb_cplusplus_does_not_suck
359 /* does not work for local types (http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2657.htm) */ 578 /* does not work for local types (http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2657.htm) */
360 template<typename T, int N> 579 template<typename T, int N>
364 } 583 }
365#else 584#else
366 #define ecb_array_length(name) (sizeof (name) / sizeof (name [0])) 585 #define ecb_array_length(name) (sizeof (name) / sizeof (name [0]))
367#endif 586#endif
368 587
588/*******************************************************************************/
589/* floating point stuff, can be disabled by defining ECB_NO_LIBM */
590
591/* basically, everything uses "ieee pure-endian" floating point numbers */
592/* the only noteworthy exception is ancient armle, which uses order 43218765 */
593#if 0 \
594 || __i386 || __i386__ \
595 || __amd64 || __amd64__ || __x86_64 || __x86_64__ \
596 || __powerpc__ || __ppc__ || __powerpc64__ || __ppc64__ \
597 || defined __arm__ && defined __ARM_EABI__ \
598 || defined __s390__ || defined __s390x__ \
599 || defined __mips__ \
600 || defined __alpha__ \
601 || defined __hppa__ \
602 || defined __ia64__ \
603 || defined __m68k__ \
604 || defined __m88k__ \
605 || defined __sh__ \
606 || defined _M_IX86 || defined _M_AMD64 || defined _M_IA64
607 #define ECB_STDFP 1
608 #include <string.h> /* for memcpy */
609#else
610 #define ECB_STDFP 0
611#endif
612
613#ifndef ECB_NO_LIBM
614
615 #include <math.h> /* for frexp*, ldexp*, INFINITY, NAN */
616
617 /* only the oldest of old doesn't have this one. solaris. */
618 #ifdef INFINITY
619 #define ECB_INFINITY INFINITY
620 #else
621 #define ECB_INFINITY HUGE_VAL
369#endif 622 #endif
370 623
624 #ifdef NAN
625 #define ECB_NAN NAN
626 #else
627 #define ECB_NAN ECB_INFINITY
628 #endif
629
630 /* converts an ieee half/binary16 to a float */
631 ecb_function_ float ecb_binary16_to_float (uint16_t x) ecb_const;
632 ecb_function_ float
633 ecb_binary16_to_float (uint16_t x)
634 {
635 int e = (x >> 10) & 0x1f;
636 int m = x & 0x3ff;
637 float r;
638
639 if (!e ) r = ldexpf (m , -24);
640 else if (e != 31) r = ldexpf (m + 0x400, e - 25);
641 else if (m ) r = ECB_NAN;
642 else r = ECB_INFINITY;
643
644 return x & 0x8000 ? -r : r;
645 }
646
647 /* convert a float to ieee single/binary32 */
648 ecb_function_ uint32_t ecb_float_to_binary32 (float x) ecb_const;
649 ecb_function_ uint32_t
650 ecb_float_to_binary32 (float x)
651 {
652 uint32_t r;
653
654 #if ECB_STDFP
655 memcpy (&r, &x, 4);
656 #else
657 /* slow emulation, works for anything but -0 */
658 uint32_t m;
659 int e;
660
661 if (x == 0e0f ) return 0x00000000U;
662 if (x > +3.40282346638528860e+38f) return 0x7f800000U;
663 if (x < -3.40282346638528860e+38f) return 0xff800000U;
664 if (x != x ) return 0x7fbfffffU;
665
666 m = frexpf (x, &e) * 0x1000000U;
667
668 r = m & 0x80000000U;
669
670 if (r)
671 m = -m;
672
673 if (e <= -126)
674 {
675 m &= 0xffffffU;
676 m >>= (-125 - e);
677 e = -126;
678 }
679
680 r |= (e + 126) << 23;
681 r |= m & 0x7fffffU;
682 #endif
683
684 return r;
685 }
686
687 /* converts an ieee single/binary32 to a float */
688 ecb_function_ float ecb_binary32_to_float (uint32_t x) ecb_const;
689 ecb_function_ float
690 ecb_binary32_to_float (uint32_t x)
691 {
692 float r;
693
694 #if ECB_STDFP
695 memcpy (&r, &x, 4);
696 #else
697 /* emulation, only works for normals and subnormals and +0 */
698 int neg = x >> 31;
699 int e = (x >> 23) & 0xffU;
700
701 x &= 0x7fffffU;
702
703 if (e)
704 x |= 0x800000U;
705 else
706 e = 1;
707
708 /* we distrust ldexpf a bit and do the 2**-24 scaling by an extra multiply */
709 r = ldexpf (x * (0.5f / 0x800000U), e - 126);
710
711 r = neg ? -r : r;
712 #endif
713
714 return r;
715 }
716
717 /* convert a double to ieee double/binary64 */
718 ecb_function_ uint64_t ecb_double_to_binary64 (double x) ecb_const;
719 ecb_function_ uint64_t
720 ecb_double_to_binary64 (double x)
721 {
722 uint64_t r;
723
724 #if ECB_STDFP
725 memcpy (&r, &x, 8);
726 #else
727 /* slow emulation, works for anything but -0 */
728 uint64_t m;
729 int e;
730
731 if (x == 0e0 ) return 0x0000000000000000U;
732 if (x > +1.79769313486231470e+308) return 0x7ff0000000000000U;
733 if (x < -1.79769313486231470e+308) return 0xfff0000000000000U;
734 if (x != x ) return 0X7ff7ffffffffffffU;
735
736 m = frexp (x, &e) * 0x20000000000000U;
737
738 r = m & 0x8000000000000000;;
739
740 if (r)
741 m = -m;
742
743 if (e <= -1022)
744 {
745 m &= 0x1fffffffffffffU;
746 m >>= (-1021 - e);
747 e = -1022;
748 }
749
750 r |= ((uint64_t)(e + 1022)) << 52;
751 r |= m & 0xfffffffffffffU;
752 #endif
753
754 return r;
755 }
756
757 /* converts an ieee double/binary64 to a double */
758 ecb_function_ double ecb_binary64_to_double (uint64_t x) ecb_const;
759 ecb_function_ double
760 ecb_binary64_to_double (uint64_t x)
761 {
762 double r;
763
764 #if ECB_STDFP
765 memcpy (&r, &x, 8);
766 #else
767 /* emulation, only works for normals and subnormals and +0 */
768 int neg = x >> 63;
769 int e = (x >> 52) & 0x7ffU;
770
771 x &= 0xfffffffffffffU;
772
773 if (e)
774 x |= 0x10000000000000U;
775 else
776 e = 1;
777
778 /* we distrust ldexp a bit and do the 2**-53 scaling by an extra multiply */
779 r = ldexp (x * (0.5 / 0x10000000000000U), e - 1022);
780
781 r = neg ? -r : r;
782 #endif
783
784 return r;
785 }
786
787#endif
788
789#endif
790

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