1 /*
2  * libecb - http://software.schmorp.de/pkg/libecb
3  *
4  * Copyright (©) 2009-2015,2018-2020 Marc Alexander Lehmann <libecb@schmorp.de>
5  * Copyright (©) 2011 Emanuele Giaquinta
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without modifica-
9  * tion, are permitted provided that the following conditions are met:
10  *
11  *   1.  Redistributions of source code must retain the above copyright notice,
12  *       this list of conditions and the following disclaimer.
13  *
14  *   2.  Redistributions in binary form must reproduce the above copyright
15  *       notice, this list of conditions and the following disclaimer in the
16  *       documentation and/or other materials provided with the distribution.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
19  * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MER-
20  * CHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO
21  * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPE-
22  * CIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
23  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
24  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
25  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTH-
26  * ERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
27  * OF THE POSSIBILITY OF SUCH DAMAGE.
28  *
29  * Alternatively, the contents of this file may be used under the terms of
30  * the GNU General Public License ("GPL") version 2 or any later version,
31  * in which case the provisions of the GPL are applicable instead of
32  * the above. If you wish to allow the use of your version of this file
33  * only under the terms of the GPL and not to allow others to use your
34  * version of this file under the BSD license, indicate your decision
35  * by deleting the provisions above and replace them with the notice
36  * and other provisions required by the GPL. If you do not delete the
37  * provisions above, a recipient may use your version of this file under
38  * either the BSD or the GPL.
39  */
40 
41 #ifndef ECB_H
42 #define ECB_H
43 
44 /* 16 bits major, 16 bits minor */
45 #define ECB_VERSION 0x00010008
46 
47 #include <string.h> /* for memcpy */
48 
49 #if defined (_WIN32) && !defined (__MINGW32__)
50   typedef   signed char   int8_t;
51   typedef unsigned char  uint8_t;
52   typedef   signed char   int_fast8_t;
53   typedef unsigned char  uint_fast8_t;
54   typedef   signed short  int16_t;
55   typedef unsigned short uint16_t;
56   typedef   signed int    int_fast16_t;
57   typedef unsigned int   uint_fast16_t;
58   typedef   signed int    int32_t;
59   typedef unsigned int   uint32_t;
60   typedef   signed int    int_fast32_t;
61   typedef unsigned int   uint_fast32_t;
62   #if __GNUC__
63     typedef   signed long long int64_t;
64     typedef unsigned long long uint64_t;
65   #else /* _MSC_VER || __BORLANDC__ */
66     typedef   signed __int64   int64_t;
67     typedef unsigned __int64   uint64_t;
68   #endif
69   typedef  int64_t  int_fast64_t;
70   typedef uint64_t uint_fast64_t;
71   #ifdef _WIN64
72     #define ECB_PTRSIZE 8
73     typedef uint64_t uintptr_t;
74     typedef  int64_t  intptr_t;
75   #else
76     #define ECB_PTRSIZE 4
77     typedef uint32_t uintptr_t;
78     typedef  int32_t  intptr_t;
79   #endif
80 #else
81   #include <inttypes.h>
82   #if (defined INTPTR_MAX ? INTPTR_MAX : ULONG_MAX) > 0xffffffffU
83     #define ECB_PTRSIZE 8
84   #else
85     #define ECB_PTRSIZE 4
86   #endif
87 #endif
88 
89 #define ECB_GCC_AMD64 (__amd64 || __amd64__ || __x86_64 || __x86_64__)
90 #define ECB_MSVC_AMD64 (_M_AMD64 || _M_X64)
91 
92 #ifndef ECB_OPTIMIZE_SIZE
93   #if __OPTIMIZE_SIZE__
94     #define ECB_OPTIMIZE_SIZE 1
95   #else
96     #define ECB_OPTIMIZE_SIZE 0
97   #endif
98 #endif
99 
100 /* work around x32 idiocy by defining proper macros */
101 #if ECB_GCC_AMD64 || ECB_MSVC_AMD64
102   #if _ILP32
103     #define ECB_AMD64_X32 1
104   #else
105     #define ECB_AMD64 1
106   #endif
107 #endif
108 
109 /* many compilers define _GNUC_ to some versions but then only implement
110  * what their idiot authors think are the "more important" extensions,
111  * causing enormous grief in return for some better fake benchmark numbers.
112  * or so.
113  * we try to detect these and simply assume they are not gcc - if they have
114  * an issue with that they should have done it right in the first place.
115  */
116 #if !defined __GNUC_MINOR__ || defined __INTEL_COMPILER || defined __SUNPRO_C || defined __SUNPRO_CC || defined __llvm__ || defined __clang__
117   #define ECB_GCC_VERSION(major,minor) 0
118 #else
119   #define ECB_GCC_VERSION(major,minor) (__GNUC__ > (major) || (__GNUC__ == (major) && __GNUC_MINOR__ >= (minor)))
120 #endif
121 
122 #define ECB_CLANG_VERSION(major,minor) (__clang_major__ > (major) || (__clang_major__ == (major) && __clang_minor__ >= (minor)))
123 
124 #if __clang__ && defined __has_builtin
125   #define ECB_CLANG_BUILTIN(x) __has_builtin (x)
126 #else
127   #define ECB_CLANG_BUILTIN(x) 0
128 #endif
129 
130 #if __clang__ && defined __has_extension
131   #define ECB_CLANG_EXTENSION(x) __has_extension (x)
132 #else
133   #define ECB_CLANG_EXTENSION(x) 0
134 #endif
135 
136 #define ECB_CPP   (__cplusplus+0)
137 #define ECB_CPP11 (__cplusplus >= 201103L)
138 #define ECB_CPP14 (__cplusplus >= 201402L)
139 #define ECB_CPP17 (__cplusplus >= 201703L)
140 
141 #if ECB_CPP
142   #define ECB_C            0
143   #define ECB_STDC_VERSION 0
144 #else
145   #define ECB_C            1
146   #define ECB_STDC_VERSION __STDC_VERSION__
147 #endif
148 
149 #define ECB_C99   (ECB_STDC_VERSION >= 199901L)
150 #define ECB_C11   (ECB_STDC_VERSION >= 201112L)
151 #define ECB_C17   (ECB_STDC_VERSION >= 201710L)
152 
153 #if ECB_CPP
154   #define ECB_EXTERN_C extern "C"
155   #define ECB_EXTERN_C_BEG ECB_EXTERN_C {
156   #define ECB_EXTERN_C_END }
157 #else
158   #define ECB_EXTERN_C extern
159   #define ECB_EXTERN_C_BEG
160   #define ECB_EXTERN_C_END
161 #endif
162 
163 /*****************************************************************************/
164 
165 /* ECB_NO_THREADS - ecb is not used by multiple threads, ever */
166 /* ECB_NO_SMP     - ecb might be used in multiple threads, but only on a single cpu */
167 
168 #if ECB_NO_THREADS
169   #define ECB_NO_SMP 1
170 #endif
171 
172 #if ECB_NO_SMP
173   #define ECB_MEMORY_FENCE do { } while (0)
174 #endif
175 
176 /* http://www-01.ibm.com/support/knowledgecenter/SSGH3R_13.1.0/com.ibm.xlcpp131.aix.doc/compiler_ref/compiler_builtins.html */
177 #if __xlC__ && ECB_CPP
178   #include <builtins.h>
179 #endif
180 
181 #if 1400 <= _MSC_VER
182   #include <intrin.h> /* fence functions _ReadBarrier, also bit search functions _BitScanReverse */
183 #endif
184 
185 #ifndef ECB_MEMORY_FENCE
186   #if ECB_GCC_VERSION(2,5) || defined __INTEL_COMPILER || (__llvm__ && __GNUC__) || __SUNPRO_C >= 0x5110 || __SUNPRO_CC >= 0x5110
187     #define ECB_MEMORY_FENCE_RELAXED __asm__ __volatile__ ("" : : : "memory")
188     #if __i386 || __i386__
189       #define ECB_MEMORY_FENCE         __asm__ __volatile__ ("lock; orb $0, -1(%%esp)" : : : "memory")
190       #define ECB_MEMORY_FENCE_ACQUIRE __asm__ __volatile__ (""                        : : : "memory")
191       #define ECB_MEMORY_FENCE_RELEASE __asm__ __volatile__ (""                        : : : "memory")
192     #elif ECB_GCC_AMD64
193       #define ECB_MEMORY_FENCE         __asm__ __volatile__ ("mfence"   : : : "memory")
194       #define ECB_MEMORY_FENCE_ACQUIRE __asm__ __volatile__ (""         : : : "memory")
195       #define ECB_MEMORY_FENCE_RELEASE __asm__ __volatile__ (""         : : : "memory")
196     #elif __powerpc__ || __ppc__ || __powerpc64__ || __ppc64__
197       #define ECB_MEMORY_FENCE         __asm__ __volatile__ ("sync"     : : : "memory")
198     #elif defined __ARM_ARCH_2__ \
199       || defined __ARM_ARCH_3__  || defined __ARM_ARCH_3M__  \
200       || defined __ARM_ARCH_4__  || defined __ARM_ARCH_4T__  \
201       || defined __ARM_ARCH_5__  || defined __ARM_ARCH_5E__  \
202       || defined __ARM_ARCH_5T__ || defined __ARM_ARCH_5TE__ \
203       || defined __ARM_ARCH_5TEJ__
204       /* should not need any, unless running old code on newer cpu - arm doesn't support that */
205     #elif defined __ARM_ARCH_6__  || defined __ARM_ARCH_6J__  \
206        || defined __ARM_ARCH_6K__ || defined __ARM_ARCH_6ZK__ \
207        || defined __ARM_ARCH_6T2__
208       #define ECB_MEMORY_FENCE         __asm__ __volatile__ ("mcr p15,0,%0,c7,c10,5" : : "r" (0) : "memory")
209     #elif defined __ARM_ARCH_7__  || defined __ARM_ARCH_7A__  \
210        || defined __ARM_ARCH_7R__ || defined __ARM_ARCH_7M__
211       #define ECB_MEMORY_FENCE         __asm__ __volatile__ ("dmb"      : : : "memory")
212     #elif __aarch64__
213       #define ECB_MEMORY_FENCE         __asm__ __volatile__ ("dmb ish"  : : : "memory")
214     #elif (__sparc || __sparc__) && !(__sparc_v8__ || defined __sparcv8)
215       #define ECB_MEMORY_FENCE         __asm__ __volatile__ ("membar #LoadStore | #LoadLoad | #StoreStore | #StoreLoad" : : : "memory")
216       #define ECB_MEMORY_FENCE_ACQUIRE __asm__ __volatile__ ("membar #LoadStore | #LoadLoad"                            : : : "memory")
217       #define ECB_MEMORY_FENCE_RELEASE __asm__ __volatile__ ("membar #LoadStore             | #StoreStore")
218     #elif defined __s390__ || defined __s390x__
219       #define ECB_MEMORY_FENCE         __asm__ __volatile__ ("bcr 15,0" : : : "memory")
220     #elif defined __mips__
221       /* GNU/Linux emulates sync on mips1 architectures, so we force its use */
222       /* anybody else who still uses mips1 is supposed to send in their version, with detection code. */
223       #define ECB_MEMORY_FENCE         __asm__ __volatile__ (".set mips2; sync; .set mips0" : : : "memory")
224     #elif defined __alpha__
225       #define ECB_MEMORY_FENCE         __asm__ __volatile__ ("mb"       : : : "memory")
226     #elif defined __hppa__
227       #define ECB_MEMORY_FENCE         __asm__ __volatile__ (""         : : : "memory")
228       #define ECB_MEMORY_FENCE_RELEASE __asm__ __volatile__ ("")
229     #elif defined __ia64__
230       #define ECB_MEMORY_FENCE         __asm__ __volatile__ ("mf"       : : : "memory")
231     #elif defined __m68k__
232       #define ECB_MEMORY_FENCE         __asm__ __volatile__ (""         : : : "memory")
233     #elif defined __m88k__
234       #define ECB_MEMORY_FENCE         __asm__ __volatile__ ("tb1 0,%%r0,128" : : : "memory")
235     #elif defined __sh__
236       #define ECB_MEMORY_FENCE         __asm__ __volatile__ (""         : : : "memory")
237     #endif
238   #endif
239 #endif
240 
241 #ifndef ECB_MEMORY_FENCE
242   #if ECB_GCC_VERSION(4,7)
243     /* see comment below (stdatomic.h) about the C11 memory model. */
244     #define ECB_MEMORY_FENCE         __atomic_thread_fence (__ATOMIC_SEQ_CST)
245     #define ECB_MEMORY_FENCE_ACQUIRE __atomic_thread_fence (__ATOMIC_ACQUIRE)
246     #define ECB_MEMORY_FENCE_RELEASE __atomic_thread_fence (__ATOMIC_RELEASE)
247     #define ECB_MEMORY_FENCE_RELAXED __atomic_thread_fence (__ATOMIC_RELAXED)
248 
249   #elif ECB_CLANG_EXTENSION(c_atomic)
250     /* see comment below (stdatomic.h) about the C11 memory model. */
251     #define ECB_MEMORY_FENCE         __c11_atomic_thread_fence (__ATOMIC_SEQ_CST)
252     #define ECB_MEMORY_FENCE_ACQUIRE __c11_atomic_thread_fence (__ATOMIC_ACQUIRE)
253     #define ECB_MEMORY_FENCE_RELEASE __c11_atomic_thread_fence (__ATOMIC_RELEASE)
254     #define ECB_MEMORY_FENCE_RELAXED __c11_atomic_thread_fence (__ATOMIC_RELAXED)
255 
256   #elif ECB_GCC_VERSION(4,4) || defined __INTEL_COMPILER || defined __clang__
257     #define ECB_MEMORY_FENCE         __sync_synchronize ()
258   #elif _MSC_VER >= 1500 /* VC++ 2008 */
259     /* apparently, microsoft broke all the memory barrier stuff in Visual Studio 2008... */
260     #pragma intrinsic(_ReadBarrier,_WriteBarrier,_ReadWriteBarrier)
261     #define ECB_MEMORY_FENCE         _ReadWriteBarrier (); MemoryBarrier()
262     #define ECB_MEMORY_FENCE_ACQUIRE _ReadWriteBarrier (); MemoryBarrier() /* according to msdn, _ReadBarrier is not a load fence */
263     #define ECB_MEMORY_FENCE_RELEASE _WriteBarrier (); MemoryBarrier()
264   #elif _MSC_VER >= 1400 /* VC++ 2005 */
265     #pragma intrinsic(_ReadBarrier,_WriteBarrier,_ReadWriteBarrier)
266     #define ECB_MEMORY_FENCE         _ReadWriteBarrier ()
267     #define ECB_MEMORY_FENCE_ACQUIRE _ReadWriteBarrier () /* according to msdn, _ReadBarrier is not a load fence */
268     #define ECB_MEMORY_FENCE_RELEASE _WriteBarrier ()
269   #elif defined _WIN32
270     #include <WinNT.h>
271     #define ECB_MEMORY_FENCE         MemoryBarrier () /* actually just xchg on x86... scary */
272   #elif __SUNPRO_C >= 0x5110 || __SUNPRO_CC >= 0x5110
273     #include <mbarrier.h>
274     #define ECB_MEMORY_FENCE         __machine_rw_barrier  ()
275     #define ECB_MEMORY_FENCE_ACQUIRE __machine_acq_barrier ()
276     #define ECB_MEMORY_FENCE_RELEASE __machine_rel_barrier ()
277     #define ECB_MEMORY_FENCE_RELAXED __compiler_barrier ()
278   #elif __xlC__
279     #define ECB_MEMORY_FENCE         __sync ()
280   #endif
281 #endif
282 
283 #ifndef ECB_MEMORY_FENCE
284   #if ECB_C11 && !defined __STDC_NO_ATOMICS__
285     /* we assume that these memory fences work on all variables/all memory accesses, */
286     /* not just C11 atomics and atomic accesses */
287     #include <stdatomic.h>
288     #define ECB_MEMORY_FENCE         atomic_thread_fence (memory_order_seq_cst)
289     #define ECB_MEMORY_FENCE_ACQUIRE atomic_thread_fence (memory_order_acquire)
290     #define ECB_MEMORY_FENCE_RELEASE atomic_thread_fence (memory_order_release)
291   #endif
292 #endif
293 
294 #ifndef ECB_MEMORY_FENCE
295   #if !ECB_AVOID_PTHREADS
296     /*
297      * if you get undefined symbol references to pthread_mutex_lock,
298      * or failure to find pthread.h, then you should implement
299      * the ECB_MEMORY_FENCE operations for your cpu/compiler
300      * OR provide pthread.h and link against the posix thread library
301      * of your system.
302      */
303     #include <pthread.h>
304     #define ECB_NEEDS_PTHREADS 1
305     #define ECB_MEMORY_FENCE_NEEDS_PTHREADS 1
306 
307     static pthread_mutex_t ecb_mf_lock = PTHREAD_MUTEX_INITIALIZER;
308     #define ECB_MEMORY_FENCE do { pthread_mutex_lock (&ecb_mf_lock); pthread_mutex_unlock (&ecb_mf_lock); } while (0)
309   #endif
310 #endif
311 
312 #if !defined ECB_MEMORY_FENCE_ACQUIRE && defined ECB_MEMORY_FENCE
313   #define ECB_MEMORY_FENCE_ACQUIRE ECB_MEMORY_FENCE
314 #endif
315 
316 #if !defined ECB_MEMORY_FENCE_RELEASE && defined ECB_MEMORY_FENCE
317   #define ECB_MEMORY_FENCE_RELEASE ECB_MEMORY_FENCE
318 #endif
319 
320 #if !defined ECB_MEMORY_FENCE_RELAXED && defined ECB_MEMORY_FENCE
321   #define ECB_MEMORY_FENCE_RELAXED ECB_MEMORY_FENCE /* very heavy-handed */
322 #endif
323 
324 /*****************************************************************************/
325 
326 #if ECB_CPP
327   #define ecb_inline static inline
328 #elif ECB_GCC_VERSION(2,5)
329   #define ecb_inline static __inline__
330 #elif ECB_C99
331   #define ecb_inline static inline
332 #else
333   #define ecb_inline static
334 #endif
335 
336 #if ECB_GCC_VERSION(3,3)
337   #define ecb_restrict __restrict__
338 #elif ECB_C99
339   #define ecb_restrict restrict
340 #else
341   #define ecb_restrict
342 #endif
343 
344 typedef int ecb_bool;
345 
346 #define ECB_CONCAT_(a, b) a ## b
347 #define ECB_CONCAT(a, b) ECB_CONCAT_(a, b)
348 #define ECB_STRINGIFY_(a) # a
349 #define ECB_STRINGIFY(a) ECB_STRINGIFY_(a)
350 #define ECB_STRINGIFY_EXPR(expr) ((expr), ECB_STRINGIFY_ (expr))
351 
352 #define ecb_function_ ecb_inline
353 
354 #if ECB_GCC_VERSION(3,1) || ECB_CLANG_VERSION(2,8)
355   #define ecb_attribute(attrlist)        __attribute__ (attrlist)
356 #else
357   #define ecb_attribute(attrlist)
358 #endif
359 
360 #if ECB_GCC_VERSION(3,1) || ECB_CLANG_BUILTIN(__builtin_constant_p)
361   #define ecb_is_constant(expr)          __builtin_constant_p (expr)
362 #else
363   /* possible C11 impl for integral types
364   typedef struct ecb_is_constant_struct ecb_is_constant_struct;
365   #define ecb_is_constant(expr)          _Generic ((1 ? (struct ecb_is_constant_struct *)0 : (void *)((expr) - (expr)), ecb_is_constant_struct *: 0, default: 1)) */
366 
367   #define ecb_is_constant(expr)          0
368 #endif
369 
370 #if ECB_GCC_VERSION(3,1) || ECB_CLANG_BUILTIN(__builtin_expect)
371   #define ecb_expect(expr,value)         __builtin_expect ((expr),(value))
372 #else
373   #define ecb_expect(expr,value)         (expr)
374 #endif
375 
376 #if ECB_GCC_VERSION(3,1) || ECB_CLANG_BUILTIN(__builtin_prefetch)
377   #define ecb_prefetch(addr,rw,locality) __builtin_prefetch (addr, rw, locality)
378 #else
379   #define ecb_prefetch(addr,rw,locality)
380 #endif
381 
382 /* no emulation for ecb_decltype */
383 #if ECB_CPP11
384   // older implementations might have problems with decltype(x)::type, work around it
385   template<class T> struct ecb_decltype_t { typedef T type; };
386   #define ecb_decltype(x) ecb_decltype_t<decltype (x)>::type
387 #elif ECB_GCC_VERSION(3,0) || ECB_CLANG_VERSION(2,8)
388   #define ecb_decltype(x) __typeof__ (x)
389 #endif
390 
391 #if _MSC_VER >= 1300
392   #define ecb_deprecated __declspec (deprecated)
393 #else
394   #define ecb_deprecated ecb_attribute ((__deprecated__))
395 #endif
396 
397 #if _MSC_VER >= 1500
398   #define ecb_deprecated_message(msg) __declspec (deprecated (msg))
399 #elif ECB_GCC_VERSION(4,5)
400   #define ecb_deprecated_message(msg) ecb_attribute ((__deprecated__ (msg))
401 #else
402   #define ecb_deprecated_message(msg) ecb_deprecated
403 #endif
404 
405 #if _MSC_VER >= 1400
406   #define ecb_noinline __declspec (noinline)
407 #else
408   #define ecb_noinline ecb_attribute ((__noinline__))
409 #endif
410 
411 #define ecb_unused     ecb_attribute ((__unused__))
412 #define ecb_const      ecb_attribute ((__const__))
413 #define ecb_pure       ecb_attribute ((__pure__))
414 
415 #if ECB_C11 || __IBMC_NORETURN
416   /* http://www-01.ibm.com/support/knowledgecenter/SSGH3R_13.1.0/com.ibm.xlcpp131.aix.doc/language_ref/noreturn.html */
417   #define ecb_noreturn   _Noreturn
418 #elif ECB_CPP11
419   #define ecb_noreturn   [[noreturn]]
420 #elif _MSC_VER >= 1200
421   /* http://msdn.microsoft.com/en-us/library/k6ktzx3s.aspx */
422   #define ecb_noreturn   __declspec (noreturn)
423 #else
424   #define ecb_noreturn   ecb_attribute ((__noreturn__))
425 #endif
426 
427 #if ECB_GCC_VERSION(4,3)
428   #define ecb_artificial ecb_attribute ((__artificial__))
429   #define ecb_hot        ecb_attribute ((__hot__))
430   #define ecb_cold       ecb_attribute ((__cold__))
431 #else
432   #define ecb_artificial
433   #define ecb_hot
434   #define ecb_cold
435 #endif
436 
437 /* put around conditional expressions if you are very sure that the  */
438 /* expression is mostly true or mostly false. note that these return */
439 /* booleans, not the expression.                                     */
440 #define ecb_expect_false(expr) ecb_expect (!!(expr), 0)
441 #define ecb_expect_true(expr)  ecb_expect (!!(expr), 1)
442 /* for compatibility to the rest of the world */
443 #define ecb_likely(expr)   ecb_expect_true  (expr)
444 #define ecb_unlikely(expr) ecb_expect_false (expr)
445 
446 /* count trailing zero bits and count # of one bits */
447 #if ECB_GCC_VERSION(3,4) \
448     || (ECB_CLANG_BUILTIN(__builtin_clz) && ECB_CLANG_BUILTIN(__builtin_clzll) \
449         && ECB_CLANG_BUILTIN(__builtin_ctz) && ECB_CLANG_BUILTIN(__builtin_ctzll) \
450         && ECB_CLANG_BUILTIN(__builtin_popcount))
451   /* we assume int == 32 bit, long == 32 or 64 bit and long long == 64 bit */
452   #define ecb_ld32(x)      (__builtin_clz      (x) ^ 31)
453   #define ecb_ld64(x)      (__builtin_clzll    (x) ^ 63)
454   #define ecb_ctz32(x)      __builtin_ctz      (x)
455   #define ecb_ctz64(x)      __builtin_ctzll    (x)
456   #define ecb_popcount32(x) __builtin_popcount (x)
457   /* no popcountll */
458 #else
459   ecb_function_ ecb_const int ecb_ctz32 (uint32_t x);
460   ecb_function_ ecb_const int
ecb_ctz32(uint32_t x)461   ecb_ctz32 (uint32_t x)
462   {
463 #if 1400 <= _MSC_VER && (_M_IX86 || _M_X64 || _M_IA64 || _M_ARM)
464     unsigned long r;
465     _BitScanForward (&r, x);
466     return (int)r;
467 #else
468     int r = 0;
469 
470     x &= ~x + 1; /* this isolates the lowest bit */
471 
472 #if ECB_branchless_on_i386
473     r += !!(x & 0xaaaaaaaa) << 0;
474     r += !!(x & 0xcccccccc) << 1;
475     r += !!(x & 0xf0f0f0f0) << 2;
476     r += !!(x & 0xff00ff00) << 3;
477     r += !!(x & 0xffff0000) << 4;
478 #else
479     if (x & 0xaaaaaaaa) r +=  1;
480     if (x & 0xcccccccc) r +=  2;
481     if (x & 0xf0f0f0f0) r +=  4;
482     if (x & 0xff00ff00) r +=  8;
483     if (x & 0xffff0000) r += 16;
484 #endif
485 
486     return r;
487 #endif
488   }
489 
490   ecb_function_ ecb_const int ecb_ctz64 (uint64_t x);
491   ecb_function_ ecb_const int
ecb_ctz64(uint64_t x)492   ecb_ctz64 (uint64_t x)
493   {
494 #if 1400 <= _MSC_VER && (_M_X64 || _M_IA64 || _M_ARM)
495     unsigned long r;
496     _BitScanForward64 (&r, x);
497     return (int)r;
498 #else
499     int shift = x & 0xffffffff ? 0 : 32;
500     return ecb_ctz32 (x >> shift) + shift;
501 #endif
502   }
503 
504   ecb_function_ ecb_const int ecb_popcount32 (uint32_t x);
505   ecb_function_ ecb_const int
ecb_popcount32(uint32_t x)506   ecb_popcount32 (uint32_t x)
507   {
508     x -=  (x >> 1) & 0x55555555;
509     x  = ((x >> 2) & 0x33333333) + (x & 0x33333333);
510     x  = ((x >> 4) + x) & 0x0f0f0f0f;
511     x *= 0x01010101;
512 
513     return x >> 24;
514   }
515 
516   ecb_function_ ecb_const int ecb_ld32 (uint32_t x);
ecb_ld32(uint32_t x)517   ecb_function_ ecb_const int ecb_ld32 (uint32_t x)
518   {
519 #if 1400 <= _MSC_VER && (_M_IX86 || _M_X64 || _M_IA64 || _M_ARM)
520     unsigned long r;
521     _BitScanReverse (&r, x);
522     return (int)r;
523 #else
524     int r = 0;
525 
526     if (x >> 16) { x >>= 16; r += 16; }
527     if (x >>  8) { x >>=  8; r +=  8; }
528     if (x >>  4) { x >>=  4; r +=  4; }
529     if (x >>  2) { x >>=  2; r +=  2; }
530     if (x >>  1) {           r +=  1; }
531 
532     return r;
533 #endif
534   }
535 
536   ecb_function_ ecb_const int ecb_ld64 (uint64_t x);
ecb_ld64(uint64_t x)537   ecb_function_ ecb_const int ecb_ld64 (uint64_t x)
538   {
539 #if 1400 <= _MSC_VER && (_M_X64 || _M_IA64 || _M_ARM)
540     unsigned long r;
541     _BitScanReverse64 (&r, x);
542     return (int)r;
543 #else
544     int r = 0;
545 
546     if (x >> 32) { x >>= 32; r += 32; }
547 
548     return r + ecb_ld32 (x);
549 #endif
550   }
551 #endif
552 
553 ecb_function_ ecb_const ecb_bool ecb_is_pot32 (uint32_t x);
ecb_is_pot32(uint32_t x)554 ecb_function_ ecb_const ecb_bool ecb_is_pot32 (uint32_t x) { return !(x & (x - 1)); }
555 ecb_function_ ecb_const ecb_bool ecb_is_pot64 (uint64_t x);
ecb_is_pot64(uint64_t x)556 ecb_function_ ecb_const ecb_bool ecb_is_pot64 (uint64_t x) { return !(x & (x - 1)); }
557 
558 ecb_function_ ecb_const uint8_t  ecb_bitrev8  (uint8_t  x);
ecb_bitrev8(uint8_t x)559 ecb_function_ ecb_const uint8_t  ecb_bitrev8  (uint8_t  x)
560 {
561   return (  (x * 0x0802U & 0x22110U)
562           | (x * 0x8020U & 0x88440U)) * 0x10101U >> 16;
563 }
564 
565 ecb_function_ ecb_const uint16_t ecb_bitrev16 (uint16_t x);
ecb_bitrev16(uint16_t x)566 ecb_function_ ecb_const uint16_t ecb_bitrev16 (uint16_t x)
567 {
568   x = ((x >>  1) &     0x5555) | ((x &     0x5555) <<  1);
569   x = ((x >>  2) &     0x3333) | ((x &     0x3333) <<  2);
570   x = ((x >>  4) &     0x0f0f) | ((x &     0x0f0f) <<  4);
571   x = ( x >>  8              ) | ( x               <<  8);
572 
573   return x;
574 }
575 
576 ecb_function_ ecb_const uint32_t ecb_bitrev32 (uint32_t x);
ecb_bitrev32(uint32_t x)577 ecb_function_ ecb_const uint32_t ecb_bitrev32 (uint32_t x)
578 {
579   x = ((x >>  1) & 0x55555555) | ((x & 0x55555555) <<  1);
580   x = ((x >>  2) & 0x33333333) | ((x & 0x33333333) <<  2);
581   x = ((x >>  4) & 0x0f0f0f0f) | ((x & 0x0f0f0f0f) <<  4);
582   x = ((x >>  8) & 0x00ff00ff) | ((x & 0x00ff00ff) <<  8);
583   x = ( x >> 16              ) | ( x               << 16);
584 
585   return x;
586 }
587 
588 /* popcount64 is only available on 64 bit cpus as gcc builtin */
589 /* so for this version we are lazy */
590 ecb_function_ ecb_const int ecb_popcount64 (uint64_t x);
591 ecb_function_ ecb_const int
ecb_popcount64(uint64_t x)592 ecb_popcount64 (uint64_t x)
593 {
594   return ecb_popcount32 (x) + ecb_popcount32 (x >> 32);
595 }
596 
597 ecb_inline ecb_const uint8_t  ecb_rotl8  (uint8_t  x, unsigned int count);
598 ecb_inline ecb_const uint8_t  ecb_rotr8  (uint8_t  x, unsigned int count);
599 ecb_inline ecb_const uint16_t ecb_rotl16 (uint16_t x, unsigned int count);
600 ecb_inline ecb_const uint16_t ecb_rotr16 (uint16_t x, unsigned int count);
601 ecb_inline ecb_const uint32_t ecb_rotl32 (uint32_t x, unsigned int count);
602 ecb_inline ecb_const uint32_t ecb_rotr32 (uint32_t x, unsigned int count);
603 ecb_inline ecb_const uint64_t ecb_rotl64 (uint64_t x, unsigned int count);
604 ecb_inline ecb_const uint64_t ecb_rotr64 (uint64_t x, unsigned int count);
605 
ecb_rotl8(uint8_t x,unsigned int count)606 ecb_inline ecb_const uint8_t  ecb_rotl8  (uint8_t  x, unsigned int count) { return (x >> ( 8 - count)) | (x << count); }
ecb_rotr8(uint8_t x,unsigned int count)607 ecb_inline ecb_const uint8_t  ecb_rotr8  (uint8_t  x, unsigned int count) { return (x << ( 8 - count)) | (x >> count); }
ecb_rotl16(uint16_t x,unsigned int count)608 ecb_inline ecb_const uint16_t ecb_rotl16 (uint16_t x, unsigned int count) { return (x >> (16 - count)) | (x << count); }
ecb_rotr16(uint16_t x,unsigned int count)609 ecb_inline ecb_const uint16_t ecb_rotr16 (uint16_t x, unsigned int count) { return (x << (16 - count)) | (x >> count); }
ecb_rotl32(uint32_t x,unsigned int count)610 ecb_inline ecb_const uint32_t ecb_rotl32 (uint32_t x, unsigned int count) { return (x >> (32 - count)) | (x << count); }
ecb_rotr32(uint32_t x,unsigned int count)611 ecb_inline ecb_const uint32_t ecb_rotr32 (uint32_t x, unsigned int count) { return (x << (32 - count)) | (x >> count); }
ecb_rotl64(uint64_t x,unsigned int count)612 ecb_inline ecb_const uint64_t ecb_rotl64 (uint64_t x, unsigned int count) { return (x >> (64 - count)) | (x << count); }
ecb_rotr64(uint64_t x,unsigned int count)613 ecb_inline ecb_const uint64_t ecb_rotr64 (uint64_t x, unsigned int count) { return (x << (64 - count)) | (x >> count); }
614 
615 #if ECB_CPP
616 
ecb_ctz(uint8_t v)617 inline uint8_t  ecb_ctz (uint8_t  v) { return ecb_ctz32 (v); }
ecb_ctz(uint16_t v)618 inline uint16_t ecb_ctz (uint16_t v) { return ecb_ctz32 (v); }
ecb_ctz(uint32_t v)619 inline uint32_t ecb_ctz (uint32_t v) { return ecb_ctz32 (v); }
ecb_ctz(uint64_t v)620 inline uint64_t ecb_ctz (uint64_t v) { return ecb_ctz64 (v); }
621 
ecb_is_pot(uint8_t v)622 inline bool ecb_is_pot (uint8_t  v) { return ecb_is_pot32 (v); }
ecb_is_pot(uint16_t v)623 inline bool ecb_is_pot (uint16_t v) { return ecb_is_pot32 (v); }
ecb_is_pot(uint32_t v)624 inline bool ecb_is_pot (uint32_t v) { return ecb_is_pot32 (v); }
ecb_is_pot(uint64_t v)625 inline bool ecb_is_pot (uint64_t v) { return ecb_is_pot64 (v); }
626 
ecb_ld(uint8_t v)627 inline int ecb_ld (uint8_t  v) { return ecb_ld32 (v); }
ecb_ld(uint16_t v)628 inline int ecb_ld (uint16_t v) { return ecb_ld32 (v); }
ecb_ld(uint32_t v)629 inline int ecb_ld (uint32_t v) { return ecb_ld32 (v); }
ecb_ld(uint64_t v)630 inline int ecb_ld (uint64_t v) { return ecb_ld64 (v); }
631 
ecb_popcount(uint8_t v)632 inline int ecb_popcount (uint8_t  v) { return ecb_popcount32 (v); }
ecb_popcount(uint16_t v)633 inline int ecb_popcount (uint16_t v) { return ecb_popcount32 (v); }
ecb_popcount(uint32_t v)634 inline int ecb_popcount (uint32_t v) { return ecb_popcount32 (v); }
ecb_popcount(uint64_t v)635 inline int ecb_popcount (uint64_t v) { return ecb_popcount64 (v); }
636 
ecb_bitrev(uint8_t v)637 inline uint8_t  ecb_bitrev (uint8_t  v) { return ecb_bitrev8  (v); }
ecb_bitrev(uint16_t v)638 inline uint16_t ecb_bitrev (uint16_t v) { return ecb_bitrev16 (v); }
ecb_bitrev(uint32_t v)639 inline uint32_t ecb_bitrev (uint32_t v) { return ecb_bitrev32 (v); }
640 
ecb_rotl(uint8_t v,unsigned int count)641 inline uint8_t  ecb_rotl (uint8_t  v, unsigned int count) { return ecb_rotl8  (v, count); }
ecb_rotl(uint16_t v,unsigned int count)642 inline uint16_t ecb_rotl (uint16_t v, unsigned int count) { return ecb_rotl16 (v, count); }
ecb_rotl(uint32_t v,unsigned int count)643 inline uint32_t ecb_rotl (uint32_t v, unsigned int count) { return ecb_rotl32 (v, count); }
ecb_rotl(uint64_t v,unsigned int count)644 inline uint64_t ecb_rotl (uint64_t v, unsigned int count) { return ecb_rotl64 (v, count); }
645 
ecb_rotr(uint8_t v,unsigned int count)646 inline uint8_t  ecb_rotr (uint8_t  v, unsigned int count) { return ecb_rotr8  (v, count); }
ecb_rotr(uint16_t v,unsigned int count)647 inline uint16_t ecb_rotr (uint16_t v, unsigned int count) { return ecb_rotr16 (v, count); }
ecb_rotr(uint32_t v,unsigned int count)648 inline uint32_t ecb_rotr (uint32_t v, unsigned int count) { return ecb_rotr32 (v, count); }
ecb_rotr(uint64_t v,unsigned int count)649 inline uint64_t ecb_rotr (uint64_t v, unsigned int count) { return ecb_rotr64 (v, count); }
650 
651 #endif
652 
653 #if ECB_GCC_VERSION(4,3) || (ECB_CLANG_BUILTIN(__builtin_bswap32) && ECB_CLANG_BUILTIN(__builtin_bswap64))
654   #if ECB_GCC_VERSION(4,8) || ECB_CLANG_BUILTIN(__builtin_bswap16)
655   #define ecb_bswap16(x)  __builtin_bswap16 (x)
656   #else
657   #define ecb_bswap16(x) (__builtin_bswap32 (x) >> 16)
658   #endif
659   #define ecb_bswap32(x)  __builtin_bswap32 (x)
660   #define ecb_bswap64(x)  __builtin_bswap64 (x)
661 #elif _MSC_VER
662   #include <stdlib.h>
663   #define ecb_bswap16(x) ((uint16_t)_byteswap_ushort ((uint16_t)(x)))
664   #define ecb_bswap32(x) ((uint32_t)_byteswap_ulong  ((uint32_t)(x)))
665   #define ecb_bswap64(x) ((uint64_t)_byteswap_uint64 ((uint64_t)(x)))
666 #else
667   ecb_function_ ecb_const uint16_t ecb_bswap16 (uint16_t x);
668   ecb_function_ ecb_const uint16_t
ecb_bswap16(uint16_t x)669   ecb_bswap16 (uint16_t x)
670   {
671     return ecb_rotl16 (x, 8);
672   }
673 
674   ecb_function_ ecb_const uint32_t ecb_bswap32 (uint32_t x);
675   ecb_function_ ecb_const uint32_t
ecb_bswap32(uint32_t x)676   ecb_bswap32 (uint32_t x)
677   {
678     return (((uint32_t)ecb_bswap16 (x)) << 16) | ecb_bswap16 (x >> 16);
679   }
680 
681   ecb_function_ ecb_const uint64_t ecb_bswap64 (uint64_t x);
682   ecb_function_ ecb_const uint64_t
ecb_bswap64(uint64_t x)683   ecb_bswap64 (uint64_t x)
684   {
685     return (((uint64_t)ecb_bswap32 (x)) << 32) | ecb_bswap32 (x >> 32);
686   }
687 #endif
688 
689 #if ECB_GCC_VERSION(4,5) || ECB_CLANG_BUILTIN(__builtin_unreachable)
690   #define ecb_unreachable() __builtin_unreachable ()
691 #else
692   /* this seems to work fine, but gcc always emits a warning for it :/ */
693   ecb_inline ecb_noreturn void ecb_unreachable (void);
ecb_unreachable(void)694   ecb_inline ecb_noreturn void ecb_unreachable (void) { }
695 #endif
696 
697 /* try to tell the compiler that some condition is definitely true */
698 #define ecb_assume(cond) if (!(cond)) ecb_unreachable (); else 0
699 
700 ecb_inline ecb_const uint32_t ecb_byteorder_helper (void);
701 ecb_inline ecb_const uint32_t
ecb_byteorder_helper(void)702 ecb_byteorder_helper (void)
703 {
704   /* the union code still generates code under pressure in gcc, */
705   /* but less than using pointers, and always seems to */
706   /* successfully return a constant. */
707   /* the reason why we have this horrible preprocessor mess */
708   /* is to avoid it in all cases, at least on common architectures */
709   /* or when using a recent enough gcc version (>= 4.6) */
710 #if (defined __BYTE_ORDER__ && __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__) \
711     || ((__i386 || __i386__ || _M_IX86 || ECB_GCC_AMD64 || ECB_MSVC_AMD64) && !__VOS__)
712   #define ECB_LITTLE_ENDIAN 1
713   return 0x44332211;
714 #elif (defined __BYTE_ORDER__ && __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__) \
715       || ((__AARCH64EB__ || __MIPSEB__ || __ARMEB__) && !__VOS__)
716   #define ECB_BIG_ENDIAN 1
717   return 0x11223344;
718 #else
719   union
720   {
721     uint8_t c[4];
722     uint32_t u;
723   } u = { 0x11, 0x22, 0x33, 0x44 };
724   return u.u;
725 #endif
726 }
727 
728 ecb_inline ecb_const ecb_bool ecb_big_endian    (void);
ecb_big_endian(void)729 ecb_inline ecb_const ecb_bool ecb_big_endian    (void) { return ecb_byteorder_helper () == 0x11223344; }
730 ecb_inline ecb_const ecb_bool ecb_little_endian (void);
ecb_little_endian(void)731 ecb_inline ecb_const ecb_bool ecb_little_endian (void) { return ecb_byteorder_helper () == 0x44332211; }
732 
733 /*****************************************************************************/
734 /* unaligned load/store */
735 
ecb_be_u16_to_host(uint_fast16_t v)736 ecb_inline uint_fast16_t ecb_be_u16_to_host (uint_fast16_t v) { return ecb_little_endian () ? ecb_bswap16 (v) : v; }
ecb_be_u32_to_host(uint_fast32_t v)737 ecb_inline uint_fast32_t ecb_be_u32_to_host (uint_fast32_t v) { return ecb_little_endian () ? ecb_bswap32 (v) : v; }
ecb_be_u64_to_host(uint_fast64_t v)738 ecb_inline uint_fast64_t ecb_be_u64_to_host (uint_fast64_t v) { return ecb_little_endian () ? ecb_bswap64 (v) : v; }
739 
ecb_le_u16_to_host(uint_fast16_t v)740 ecb_inline uint_fast16_t ecb_le_u16_to_host (uint_fast16_t v) { return ecb_big_endian    () ? ecb_bswap16 (v) : v; }
ecb_le_u32_to_host(uint_fast32_t v)741 ecb_inline uint_fast32_t ecb_le_u32_to_host (uint_fast32_t v) { return ecb_big_endian    () ? ecb_bswap32 (v) : v; }
ecb_le_u64_to_host(uint_fast64_t v)742 ecb_inline uint_fast64_t ecb_le_u64_to_host (uint_fast64_t v) { return ecb_big_endian    () ? ecb_bswap64 (v) : v; }
743 
ecb_peek_u16_u(const void * ptr)744 ecb_inline uint_fast16_t ecb_peek_u16_u (const void *ptr) { uint16_t v; memcpy (&v, ptr, sizeof (v)); return v; }
ecb_peek_u32_u(const void * ptr)745 ecb_inline uint_fast32_t ecb_peek_u32_u (const void *ptr) { uint32_t v; memcpy (&v, ptr, sizeof (v)); return v; }
ecb_peek_u64_u(const void * ptr)746 ecb_inline uint_fast64_t ecb_peek_u64_u (const void *ptr) { uint64_t v; memcpy (&v, ptr, sizeof (v)); return v; }
747 
ecb_peek_be_u16_u(const void * ptr)748 ecb_inline uint_fast16_t ecb_peek_be_u16_u (const void *ptr) { return ecb_be_u16_to_host (ecb_peek_u16_u (ptr)); }
ecb_peek_be_u32_u(const void * ptr)749 ecb_inline uint_fast32_t ecb_peek_be_u32_u (const void *ptr) { return ecb_be_u32_to_host (ecb_peek_u32_u (ptr)); }
ecb_peek_be_u64_u(const void * ptr)750 ecb_inline uint_fast64_t ecb_peek_be_u64_u (const void *ptr) { return ecb_be_u64_to_host (ecb_peek_u64_u (ptr)); }
751 
ecb_peek_le_u16_u(const void * ptr)752 ecb_inline uint_fast16_t ecb_peek_le_u16_u (const void *ptr) { return ecb_le_u16_to_host (ecb_peek_u16_u (ptr)); }
ecb_peek_le_u32_u(const void * ptr)753 ecb_inline uint_fast32_t ecb_peek_le_u32_u (const void *ptr) { return ecb_le_u32_to_host (ecb_peek_u32_u (ptr)); }
ecb_peek_le_u64_u(const void * ptr)754 ecb_inline uint_fast64_t ecb_peek_le_u64_u (const void *ptr) { return ecb_le_u64_to_host (ecb_peek_u64_u (ptr)); }
755 
ecb_host_to_be_u16(uint_fast16_t v)756 ecb_inline uint_fast16_t ecb_host_to_be_u16 (uint_fast16_t v) { return ecb_little_endian () ? ecb_bswap16 (v) : v; }
ecb_host_to_be_u32(uint_fast32_t v)757 ecb_inline uint_fast32_t ecb_host_to_be_u32 (uint_fast32_t v) { return ecb_little_endian () ? ecb_bswap32 (v) : v; }
ecb_host_to_be_u64(uint_fast64_t v)758 ecb_inline uint_fast64_t ecb_host_to_be_u64 (uint_fast64_t v) { return ecb_little_endian () ? ecb_bswap64 (v) : v; }
759 
ecb_host_to_le_u16(uint_fast16_t v)760 ecb_inline uint_fast16_t ecb_host_to_le_u16 (uint_fast16_t v) { return ecb_big_endian    () ? ecb_bswap16 (v) : v; }
ecb_host_to_le_u32(uint_fast32_t v)761 ecb_inline uint_fast32_t ecb_host_to_le_u32 (uint_fast32_t v) { return ecb_big_endian    () ? ecb_bswap32 (v) : v; }
ecb_host_to_le_u64(uint_fast64_t v)762 ecb_inline uint_fast64_t ecb_host_to_le_u64 (uint_fast64_t v) { return ecb_big_endian    () ? ecb_bswap64 (v) : v; }
763 
ecb_poke_u16_u(void * ptr,uint16_t v)764 ecb_inline void ecb_poke_u16_u (void *ptr, uint16_t v) { memcpy (ptr, &v, sizeof (v)); }
ecb_poke_u32_u(void * ptr,uint32_t v)765 ecb_inline void ecb_poke_u32_u (void *ptr, uint32_t v) { memcpy (ptr, &v, sizeof (v)); }
ecb_poke_u64_u(void * ptr,uint64_t v)766 ecb_inline void ecb_poke_u64_u (void *ptr, uint64_t v) { memcpy (ptr, &v, sizeof (v)); }
767 
ecb_poke_be_u16_u(void * ptr,uint_fast16_t v)768 ecb_inline void ecb_poke_be_u16_u (void *ptr, uint_fast16_t v) { ecb_poke_u16_u (ptr, ecb_host_to_be_u16 (v)); }
ecb_poke_be_u32_u(void * ptr,uint_fast32_t v)769 ecb_inline void ecb_poke_be_u32_u (void *ptr, uint_fast32_t v) { ecb_poke_u32_u (ptr, ecb_host_to_be_u32 (v)); }
ecb_poke_be_u64_u(void * ptr,uint_fast64_t v)770 ecb_inline void ecb_poke_be_u64_u (void *ptr, uint_fast64_t v) { ecb_poke_u64_u (ptr, ecb_host_to_be_u64 (v)); }
771 
ecb_poke_le_u16_u(void * ptr,uint_fast16_t v)772 ecb_inline void ecb_poke_le_u16_u (void *ptr, uint_fast16_t v) { ecb_poke_u16_u (ptr, ecb_host_to_le_u16 (v)); }
ecb_poke_le_u32_u(void * ptr,uint_fast32_t v)773 ecb_inline void ecb_poke_le_u32_u (void *ptr, uint_fast32_t v) { ecb_poke_u32_u (ptr, ecb_host_to_le_u32 (v)); }
ecb_poke_le_u64_u(void * ptr,uint_fast64_t v)774 ecb_inline void ecb_poke_le_u64_u (void *ptr, uint_fast64_t v) { ecb_poke_u64_u (ptr, ecb_host_to_le_u64 (v)); }
775 
776 #if ECB_CPP
777 
ecb_bswap(uint8_t v)778 inline uint8_t  ecb_bswap (uint8_t  v) { return v; }
ecb_bswap(uint16_t v)779 inline uint16_t ecb_bswap (uint16_t v) { return ecb_bswap16 (v); }
ecb_bswap(uint32_t v)780 inline uint32_t ecb_bswap (uint32_t v) { return ecb_bswap32 (v); }
ecb_bswap(uint64_t v)781 inline uint64_t ecb_bswap (uint64_t v) { return ecb_bswap64 (v); }
782 
ecb_be_to_host(T v)783 template<typename T> inline T ecb_be_to_host (T v) { return ecb_little_endian () ? ecb_bswap (v) : v; }
ecb_le_to_host(T v)784 template<typename T> inline T ecb_le_to_host (T v) { return ecb_big_endian    () ? ecb_bswap (v) : v; }
ecb_peek(const void * ptr)785 template<typename T> inline T ecb_peek       (const void *ptr) { return *(const T *)ptr; }
ecb_peek_be(const void * ptr)786 template<typename T> inline T ecb_peek_be    (const void *ptr) { return ecb_be_to_host (ecb_peek  <T> (ptr)); }
ecb_peek_le(const void * ptr)787 template<typename T> inline T ecb_peek_le    (const void *ptr) { return ecb_le_to_host (ecb_peek  <T> (ptr)); }
ecb_peek_u(const void * ptr)788 template<typename T> inline T ecb_peek_u     (const void *ptr) { T v; memcpy (&v, ptr, sizeof (v)); return v; }
ecb_peek_be_u(const void * ptr)789 template<typename T> inline T ecb_peek_be_u  (const void *ptr) { return ecb_be_to_host (ecb_peek_u<T> (ptr)); }
ecb_peek_le_u(const void * ptr)790 template<typename T> inline T ecb_peek_le_u  (const void *ptr) { return ecb_le_to_host (ecb_peek_u<T> (ptr)); }
791 
ecb_host_to_be(T v)792 template<typename T> inline T ecb_host_to_be (T v) { return ecb_little_endian () ? ecb_bswap (v) : v; }
ecb_host_to_le(T v)793 template<typename T> inline T ecb_host_to_le (T v) { return ecb_big_endian    () ? ecb_bswap (v) : v; }
ecb_poke(void * ptr,T v)794 template<typename T> inline void ecb_poke      (void *ptr, T v) { *(T *)ptr = v; }
ecb_poke_be(void * ptr,T v)795 template<typename T> inline void ecb_poke_be   (void *ptr, T v) { return ecb_poke  <T> (ptr, ecb_host_to_be (v)); }
ecb_poke_le(void * ptr,T v)796 template<typename T> inline void ecb_poke_le   (void *ptr, T v) { return ecb_poke  <T> (ptr, ecb_host_to_le (v)); }
ecb_poke_u(void * ptr,T v)797 template<typename T> inline void ecb_poke_u    (void *ptr, T v) { memcpy (ptr, &v, sizeof (v)); }
ecb_poke_be_u(void * ptr,T v)798 template<typename T> inline void ecb_poke_be_u (void *ptr, T v) { return ecb_poke_u<T> (ptr, ecb_host_to_be (v)); }
ecb_poke_le_u(void * ptr,T v)799 template<typename T> inline void ecb_poke_le_u (void *ptr, T v) { return ecb_poke_u<T> (ptr, ecb_host_to_le (v)); }
800 
801 #endif
802 
803 /*****************************************************************************/
804 
805 #if ECB_GCC_VERSION(3,0) || ECB_C99
806   #define ecb_mod(m,n) ((m) % (n) + ((m) % (n) < 0 ? (n) : 0))
807 #else
808   #define ecb_mod(m,n) ((m) < 0 ? ((n) - 1 - ((-1 - (m)) % (n))) : ((m) % (n)))
809 #endif
810 
811 #if ECB_CPP
812   template<typename T>
ecb_div_rd(T val,T div)813   static inline T ecb_div_rd (T val, T div)
814   {
815     return val < 0 ? - ((-val + div - 1) / div) : (val          ) / div;
816   }
817   template<typename T>
ecb_div_ru(T val,T div)818   static inline T ecb_div_ru (T val, T div)
819   {
820     return val < 0 ? - ((-val          ) / div) : (val + div - 1) / div;
821   }
822 #else
823   #define ecb_div_rd(val,div) ((val) < 0 ? - ((-(val) + (div) - 1) / (div)) : ((val)            ) / (div))
824   #define ecb_div_ru(val,div) ((val) < 0 ? - ((-(val)            ) / (div)) : ((val) + (div) - 1) / (div))
825 #endif
826 
827 #if ecb_cplusplus_does_not_suck
828   /* does not work for local types (http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2657.htm) */
829   template<typename T, int N>
ecb_array_length(const T (& arr)[N])830   static inline int ecb_array_length (const T (&arr)[N])
831   {
832     return N;
833   }
834 #else
835   #define ecb_array_length(name) (sizeof (name) / sizeof (name [0]))
836 #endif
837 
838 /*****************************************************************************/
839 
840 ecb_function_ ecb_const uint32_t ecb_binary16_to_binary32 (uint32_t x);
841 ecb_function_ ecb_const uint32_t
ecb_binary16_to_binary32(uint32_t x)842 ecb_binary16_to_binary32 (uint32_t x)
843 {
844   unsigned int s = (x & 0x8000) << (31 - 15);
845   int          e = (x >> 10) & 0x001f;
846   unsigned int m =  x        & 0x03ff;
847 
848   if (ecb_expect_false (e == 31))
849     /* infinity or NaN */
850     e = 255 - (127 - 15);
851   else if (ecb_expect_false (!e))
852     {
853       if (ecb_expect_true (!m))
854         /* zero, handled by code below by forcing e to 0 */
855         e = 0 - (127 - 15);
856       else
857         {
858           /* subnormal, renormalise */
859           unsigned int s = 10 - ecb_ld32 (m);
860 
861           m = (m << s) & 0x3ff; /* mask implicit bit */
862           e -= s - 1;
863         }
864     }
865 
866   /* e and m now are normalised, or zero, (or inf or nan) */
867   e += 127 - 15;
868 
869   return s | (e << 23) | (m << (23 - 10));
870 }
871 
872 ecb_function_ ecb_const uint16_t ecb_binary32_to_binary16 (uint32_t x);
873 ecb_function_ ecb_const uint16_t
ecb_binary32_to_binary16(uint32_t x)874 ecb_binary32_to_binary16 (uint32_t x)
875 {
876   unsigned int s =  (x >> 16) & 0x00008000; /* sign bit, the easy part */
877   unsigned int e = ((x >> 23) & 0x000000ff) - (127 - 15); /* the desired exponent */
878   unsigned int m =   x        & 0x007fffff;
879 
880   x &= 0x7fffffff;
881 
882   /* if it's within range of binary16 normals, use fast path */
883   if (ecb_expect_true (0x38800000 <= x && x <= 0x477fefff))
884     {
885       /* mantissa round-to-even */
886       m += 0x00000fff + ((m >> (23 - 10)) & 1);
887 
888       /* handle overflow */
889       if (ecb_expect_false (m >= 0x00800000))
890         {
891           m >>= 1;
892           e +=  1;
893         }
894 
895       return s | (e << 10) | (m >> (23 - 10));
896     }
897 
898   /* handle large numbers and infinity */
899   if (ecb_expect_true (0x477fefff < x && x <= 0x7f800000))
900     return s | 0x7c00;
901 
902   /* handle zero, subnormals and small numbers */
903   if (ecb_expect_true (x < 0x38800000))
904     {
905       /* zero */
906       if (ecb_expect_true (!x))
907         return s;
908 
909       /* handle subnormals */
910 
911       /* too small, will be zero */
912       if (e < (14 - 24)) /* might not be sharp, but is good enough */
913         return s;
914 
915       m |= 0x00800000; /* make implicit bit explicit */
916 
917       /* very tricky - we need to round to the nearest e (+10) bit value */
918       {
919         unsigned int bits = 14 - e;
920         unsigned int half = (1 << (bits - 1)) - 1;
921         unsigned int even = (m >> bits) & 1;
922 
923         /* if this overflows, we will end up with a normalised number */
924         m = (m + half + even) >> bits;
925       }
926 
927       return s | m;
928     }
929 
930   /* handle NaNs, preserve leftmost nan bits, but make sure we don't turn them into infinities */
931   m >>= 13;
932 
933   return s | 0x7c00 | m | !m;
934 }
935 
936 /*******************************************************************************/
937 /* floating point stuff, can be disabled by defining ECB_NO_LIBM */
938 
939 /* basically, everything uses "ieee pure-endian" floating point numbers */
940 /* the only noteworthy exception is ancient armle, which uses order 43218765 */
941 #if 0 \
942     || __i386 || __i386__ \
943     || ECB_GCC_AMD64 \
944     || __powerpc__ || __ppc__ || __powerpc64__ || __ppc64__ \
945     || defined __s390__ || defined __s390x__ \
946     || defined __mips__ \
947     || defined __alpha__ \
948     || defined __hppa__ \
949     || defined __ia64__ \
950     || defined __m68k__ \
951     || defined __m88k__ \
952     || defined __sh__ \
953     || defined _M_IX86 || defined ECB_MSVC_AMD64 || defined _M_IA64 \
954     || (defined __arm__ && (defined __ARM_EABI__ || defined __EABI__ || defined __VFP_FP__ || defined _WIN32_WCE || defined __ANDROID__)) \
955     || defined __aarch64__
956   #define ECB_STDFP 1
957 #else
958   #define ECB_STDFP 0
959 #endif
960 
961 #ifndef ECB_NO_LIBM
962 
963   #include <math.h> /* for frexp*, ldexp*, INFINITY, NAN */
964 
965   /* only the oldest of old doesn't have this one. solaris. */
966   #ifdef INFINITY
967     #define ECB_INFINITY INFINITY
968   #else
969     #define ECB_INFINITY HUGE_VAL
970   #endif
971 
972   #ifdef NAN
973     #define ECB_NAN NAN
974   #else
975     #define ECB_NAN ECB_INFINITY
976   #endif
977 
978   #if ECB_C99 || _XOPEN_VERSION >= 600 || _POSIX_VERSION >= 200112L
979     #define ecb_ldexpf(x,e) ldexpf ((x), (e))
980     #define ecb_frexpf(x,e) frexpf ((x), (e))
981   #else
982     #define ecb_ldexpf(x,e) (float) ldexp ((double) (x), (e))
983     #define ecb_frexpf(x,e) (float) frexp ((double) (x), (e))
984   #endif
985 
986   /* convert a float to ieee single/binary32 */
987   ecb_function_ ecb_const uint32_t ecb_float_to_binary32 (float x);
988   ecb_function_ ecb_const uint32_t
ecb_float_to_binary32(float x)989   ecb_float_to_binary32 (float x)
990   {
991     uint32_t r;
992 
993     #if ECB_STDFP
994       memcpy (&r, &x, 4);
995     #else
996       /* slow emulation, works for anything but -0 */
997       uint32_t m;
998       int e;
999 
1000       if (x == 0e0f                    ) return 0x00000000U;
1001       if (x > +3.40282346638528860e+38f) return 0x7f800000U;
1002       if (x < -3.40282346638528860e+38f) return 0xff800000U;
1003       if (x != x                       ) return 0x7fbfffffU;
1004 
1005       m = ecb_frexpf (x, &e) * 0x1000000U;
1006 
1007       r = m & 0x80000000U;
1008 
1009       if (r)
1010         m = -m;
1011 
1012       if (e <= -126)
1013         {
1014           m &= 0xffffffU;
1015           m >>= (-125 - e);
1016           e = -126;
1017         }
1018 
1019       r |= (e + 126) << 23;
1020       r |= m & 0x7fffffU;
1021     #endif
1022 
1023     return r;
1024   }
1025 
1026   /* converts an ieee single/binary32 to a float */
1027   ecb_function_ ecb_const float ecb_binary32_to_float (uint32_t x);
1028   ecb_function_ ecb_const float
ecb_binary32_to_float(uint32_t x)1029   ecb_binary32_to_float (uint32_t x)
1030   {
1031     float r;
1032 
1033     #if ECB_STDFP
1034       memcpy (&r, &x, 4);
1035     #else
1036       /* emulation, only works for normals and subnormals and +0 */
1037       int neg = x >> 31;
1038       int e = (x >> 23) & 0xffU;
1039 
1040       x &= 0x7fffffU;
1041 
1042       if (e)
1043         x |= 0x800000U;
1044       else
1045         e = 1;
1046 
1047       /* we distrust ldexpf a bit and do the 2**-24 scaling by an extra multiply */
1048       r = ecb_ldexpf (x * (0.5f / 0x800000U), e - 126);
1049 
1050       r = neg ? -r : r;
1051     #endif
1052 
1053     return r;
1054   }
1055 
1056   /* convert a double to ieee double/binary64 */
1057   ecb_function_ ecb_const uint64_t ecb_double_to_binary64 (double x);
1058   ecb_function_ ecb_const uint64_t
ecb_double_to_binary64(double x)1059   ecb_double_to_binary64 (double x)
1060   {
1061     uint64_t r;
1062 
1063     #if ECB_STDFP
1064       memcpy (&r, &x, 8);
1065     #else
1066       /* slow emulation, works for anything but -0 */
1067       uint64_t m;
1068       int e;
1069 
1070       if (x == 0e0                     ) return 0x0000000000000000U;
1071       if (x > +1.79769313486231470e+308) return 0x7ff0000000000000U;
1072       if (x < -1.79769313486231470e+308) return 0xfff0000000000000U;
1073       if (x != x                       ) return 0X7ff7ffffffffffffU;
1074 
1075       m = frexp (x, &e) * 0x20000000000000U;
1076 
1077       r = m & 0x8000000000000000;;
1078 
1079       if (r)
1080         m = -m;
1081 
1082       if (e <= -1022)
1083         {
1084           m &= 0x1fffffffffffffU;
1085           m >>= (-1021 - e);
1086           e = -1022;
1087         }
1088 
1089       r |= ((uint64_t)(e + 1022)) << 52;
1090       r |= m & 0xfffffffffffffU;
1091     #endif
1092 
1093     return r;
1094   }
1095 
1096   /* converts an ieee double/binary64 to a double */
1097   ecb_function_ ecb_const double ecb_binary64_to_double (uint64_t x);
1098   ecb_function_ ecb_const double
ecb_binary64_to_double(uint64_t x)1099   ecb_binary64_to_double (uint64_t x)
1100   {
1101     double r;
1102 
1103     #if ECB_STDFP
1104       memcpy (&r, &x, 8);
1105     #else
1106       /* emulation, only works for normals and subnormals and +0 */
1107       int neg = x >> 63;
1108       int e = (x >> 52) & 0x7ffU;
1109 
1110       x &= 0xfffffffffffffU;
1111 
1112       if (e)
1113         x |= 0x10000000000000U;
1114       else
1115         e = 1;
1116 
1117       /* we distrust ldexp a bit and do the 2**-53 scaling by an extra multiply */
1118       r = ldexp (x * (0.5 / 0x10000000000000U), e - 1022);
1119 
1120       r = neg ? -r : r;
1121     #endif
1122 
1123     return r;
1124   }
1125 
1126   /* convert a float to ieee half/binary16 */
1127   ecb_function_ ecb_const uint16_t ecb_float_to_binary16 (float x);
1128   ecb_function_ ecb_const uint16_t
ecb_float_to_binary16(float x)1129   ecb_float_to_binary16 (float x)
1130   {
1131     return ecb_binary32_to_binary16 (ecb_float_to_binary32 (x));
1132   }
1133 
1134   /* convert an ieee half/binary16 to float */
1135   ecb_function_ ecb_const float ecb_binary16_to_float (uint16_t x);
1136   ecb_function_ ecb_const float
ecb_binary16_to_float(uint16_t x)1137   ecb_binary16_to_float (uint16_t x)
1138   {
1139     return ecb_binary32_to_float (ecb_binary16_to_binary32 (x));
1140   }
1141 
1142 #endif
1143 
1144 #endif
1145 
1146