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Comparing libecb/ecb.h (file contents):
Revision 1.90 by root, Tue May 29 14:09:49 2012 UTC vs.
Revision 1.126 by root, Sun Jan 5 02:58:29 2014 UTC

1/* 1/*
2 * libecb - http://software.schmorp.de/pkg/libecb 2 * libecb - http://software.schmorp.de/pkg/libecb
3 * 3 *
4 * Copyright (©) 2009-2012 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:
… …
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 */ 33/* 16 bits major, 16 bits minor */
34#define ECB_VERSION 0x00010001 34#define ECB_VERSION 0x00010003
35 35
36#ifdef _WIN32 36#ifdef _WIN32
37 typedef signed char int8_t; 37 typedef signed char int8_t;
38 typedef unsigned char uint8_t; 38 typedef unsigned char uint8_t;
39 typedef signed short int16_t; 39 typedef signed short int16_t;
… …
54 #else 54 #else
55 #define ECB_PTRSIZE 4 55 #define ECB_PTRSIZE 4
56 typedef uint32_t uintptr_t; 56 typedef uint32_t uintptr_t;
57 typedef int32_t intptr_t; 57 typedef int32_t intptr_t;
58 #endif 58 #endif
59 typedef intptr_t ptrdiff_t;
60#else 59#else
61 #include <inttypes.h> 60 #include <inttypes.h>
62 #if UINTMAX_MAX > 0xffffffffU 61 #if UINTMAX_MAX > 0xffffffffU
63 #define ECB_PTRSIZE 8 62 #define ECB_PTRSIZE 8
64 #else 63 #else
65 #define ECB_PTRSIZE 4 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
66 #endif 74 #endif
67#endif 75#endif
68 76
69/* many compilers define _GNUC_ to some versions but then only implement 77/* many compilers define _GNUC_ to some versions but then only implement
70 * what their idiot authors think are the "more important" extensions, 78 * what their idiot authors think are the "more important" extensions,
… …
79 #else 87 #else
80 #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)))
81 #endif 89 #endif
82#endif 90#endif
83 91
92#define ECB_C (__STDC__+0) /* this assumes that __STDC__ is either empty or a number */
84#define ECB_C99 (__STDC_VERSION__ >= 199901L) 93#define ECB_C99 (__STDC_VERSION__ >= 199901L)
85#define ECB_C11 (__STDC_VERSION__ >= 201112L) 94#define ECB_C11 (__STDC_VERSION__ >= 201112L)
95#define ECB_CPP (__cplusplus+0)
96#define ECB_CPP11 (__cplusplus >= 201103L)
97
98#if ECB_CPP
99 #define ECB_EXTERN_C extern "C"
100 #define ECB_EXTERN_C_BEG ECB_EXTERN_C {
101 #define ECB_EXTERN_C_END }
102#else
103 #define ECB_EXTERN_C extern
104 #define ECB_EXTERN_C_BEG
105 #define ECB_EXTERN_C_END
106#endif
86 107
87/*****************************************************************************/ 108/*****************************************************************************/
88 109
89/* ECB_NO_THREADS - ecb is not used by multiple threads, ever */ 110/* ECB_NO_THREADS - ecb is not used by multiple threads, ever */
90/* ECB_NO_SMP - ecb might be used in multiple threads, but only on a single cpu */ 111/* ECB_NO_SMP - ecb might be used in multiple threads, but only on a single cpu */
91 112
92#if ECB_NO_THREADS 113#if ECB_NO_THREADS
93# define ECB_NO_SMP 1 114 #define ECB_NO_SMP 1
94#endif 115#endif
95 116
96#if ECB_NO_THREADS || ECB_NO_SMP 117#if ECB_NO_SMP
97 #define ECB_MEMORY_FENCE do { } while (0) 118 #define ECB_MEMORY_FENCE do { } while (0)
98#endif
99
100#ifndef ECB_MEMORY_FENCE
101 #if ECB_C11 && !defined __STDC_NO_ATOMICS__
102 /* we assume that these memory fences work on all variables/all memory accesses, */
103 /* not just C11 atomics and atomic accesses */
104 #include <stdatomic.h>
105 #define ECB_MEMORY_FENCE atomic_thread_fence (memory_order_acq_rel)
106 #define ECB_MEMORY_FENCE_ACQUIRE atomic_thread_fence (memory_order_acquire)
107 #define ECB_MEMORY_FENCE_RELEASE atomic_thread_fence (memory_order_release)
108 #endif
109#endif 119#endif
110 120
111#ifndef ECB_MEMORY_FENCE 121#ifndef ECB_MEMORY_FENCE
112 #if ECB_GCC_VERSION(2,5) || defined __INTEL_COMPILER || (__llvm__ && __GNUC__) || __SUNPRO_C >= 0x5110 || __SUNPRO_CC >= 0x5110 122 #if ECB_GCC_VERSION(2,5) || defined __INTEL_COMPILER || (__llvm__ && __GNUC__) || __SUNPRO_C >= 0x5110 || __SUNPRO_CC >= 0x5110
113 #if __i386 || __i386__ 123 #if __i386 || __i386__
114 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("lock; orb $0, -1(%%esp)" : : : "memory") 124 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("lock; orb $0, -1(%%esp)" : : : "memory")
115 #define ECB_MEMORY_FENCE_ACQUIRE ECB_MEMORY_FENCE /* non-lock xchg might be enough */ 125 #define ECB_MEMORY_FENCE_ACQUIRE __asm__ __volatile__ ("" : : : "memory")
116 #define ECB_MEMORY_FENCE_RELEASE do { } while (0) /* unlikely to change in future cpus */ 126 #define ECB_MEMORY_FENCE_RELEASE __asm__ __volatile__ ("")
117 #elif __amd64 || __amd64__ || __x86_64 || __x86_64__ 127 #elif __amd64 || __amd64__ || __x86_64 || __x86_64__
118 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("mfence" : : : "memory") 128 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("mfence" : : : "memory")
119 #define ECB_MEMORY_FENCE_ACQUIRE __asm__ __volatile__ ("lfence" : : : "memory") 129 #define ECB_MEMORY_FENCE_ACQUIRE __asm__ __volatile__ ("" : : : "memory")
120 #define ECB_MEMORY_FENCE_RELEASE __asm__ __volatile__ ("sfence") /* play safe - not needed in any current cpu */ 130 #define ECB_MEMORY_FENCE_RELEASE __asm__ __volatile__ ("")
121 #elif __powerpc__ || __ppc__ || __powerpc64__ || __ppc64__ 131 #elif __powerpc__ || __ppc__ || __powerpc64__ || __ppc64__
122 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("sync" : : : "memory") 132 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("sync" : : : "memory")
123 #elif defined __ARM_ARCH_6__ || defined __ARM_ARCH_6J__ \ 133 #elif defined __ARM_ARCH_6__ || defined __ARM_ARCH_6J__ \
124 || defined __ARM_ARCH_6K__ || defined __ARM_ARCH_6ZK__ 134 || defined __ARM_ARCH_6K__ || defined __ARM_ARCH_6ZK__
125 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("mcr p15,0,%0,c7,c10,5" : : "r" (0) : "memory") 135 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("mcr p15,0,%0,c7,c10,5" : : "r" (0) : "memory")
126 #elif defined __ARM_ARCH_7__ || defined __ARM_ARCH_7A__ \ 136 #elif defined __ARM_ARCH_7__ || defined __ARM_ARCH_7A__ \
127 || defined __ARM_ARCH_7M__ || defined __ARM_ARCH_7R__ 137 || defined __ARM_ARCH_7M__ || defined __ARM_ARCH_7R__
128 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("dmb" : : : "memory") 138 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("dmb" : : : "memory")
129 #elif __sparc || __sparc__ 139 #elif (__sparc || __sparc__) && !__sparcv8
130 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("membar #LoadStore | #LoadLoad | #StoreStore | #StoreLoad | " : : : "memory") 140 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("membar #LoadStore | #LoadLoad | #StoreStore | #StoreLoad" : : : "memory")
131 #define ECB_MEMORY_FENCE_ACQUIRE __asm__ __volatile__ ("membar #LoadStore | #LoadLoad" : : : "memory") 141 #define ECB_MEMORY_FENCE_ACQUIRE __asm__ __volatile__ ("membar #LoadStore | #LoadLoad" : : : "memory")
132 #define ECB_MEMORY_FENCE_RELEASE __asm__ __volatile__ ("membar #LoadStore | #StoreStore") 142 #define ECB_MEMORY_FENCE_RELEASE __asm__ __volatile__ ("membar #LoadStore | #StoreStore")
133 #elif defined __s390__ || defined __s390x__ 143 #elif defined __s390__ || defined __s390x__
134 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("bcr 15,0" : : : "memory") 144 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("bcr 15,0" : : : "memory")
135 #elif defined __mips__ 145 #elif defined __mips__
146 /* GNU/Linux emulates sync on mips1 architectures, so we force its use */
147 /* anybody else who still uses mips1 is supposed to send in their version, with detection code. */
136 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("sync" : : : "memory") 148 #define ECB_MEMORY_FENCE __asm__ __volatile__ (".set mips2; sync; .set mips0" : : : "memory")
137 #elif defined __alpha__ 149 #elif defined __alpha__
138 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("mb" : : : "memory") 150 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("mb" : : : "memory")
151 #elif defined __hppa__
152 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("" : : : "memory")
153 #define ECB_MEMORY_FENCE_RELEASE __asm__ __volatile__ ("")
154 #elif defined __ia64__
155 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("mf" : : : "memory")
156 #elif defined __m68k__
157 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("" : : : "memory")
158 #elif defined __m88k__
159 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("tb1 0,%%r0,128" : : : "memory")
160 #elif defined __sh__
161 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("" : : : "memory")
139 #endif 162 #endif
140 #endif 163 #endif
141#endif 164#endif
142 165
143#ifndef ECB_MEMORY_FENCE 166#ifndef ECB_MEMORY_FENCE
167 #if ECB_GCC_VERSION(4,7)
168 /* see comment below (stdatomic.h) about the C11 memory model. */
169 #define ECB_MEMORY_FENCE __atomic_thread_fence (__ATOMIC_SEQ_CST)
170
171 /* The __has_feature syntax from clang is so misdesigned that we cannot use it
172 * without risking compile time errors with other compilers. We *could*
173 * define our own ecb_clang_has_feature, but I just can't be bothered to work
174 * around this shit time and again.
175 * #elif defined __clang && __has_feature (cxx_atomic)
176 * // see comment below (stdatomic.h) about the C11 memory model.
177 * #define ECB_MEMORY_FENCE __c11_atomic_thread_fence (__ATOMIC_SEQ_CST)
178 */
179
144 #if ECB_GCC_VERSION(4,4) || defined __INTEL_COMPILER || defined __clang__ 180 #elif ECB_GCC_VERSION(4,4) || defined __INTEL_COMPILER || defined __clang__
145 #define ECB_MEMORY_FENCE __sync_synchronize () 181 #define ECB_MEMORY_FENCE __sync_synchronize ()
146 /*#define ECB_MEMORY_FENCE_ACQUIRE ({ char dummy = 0; __sync_lock_test_and_set (&dummy, 1); }) */ 182 #elif _MSC_VER >= 1500 /* VC++ 2008 */
147 /*#define ECB_MEMORY_FENCE_RELEASE ({ char dummy = 1; __sync_lock_release (&dummy ); }) */ 183 /* apparently, microsoft broke all the memory barrier stuff in Visual Studio 2008... */
184 #pragma intrinsic(_ReadBarrier,_WriteBarrier,_ReadWriteBarrier)
185 #define ECB_MEMORY_FENCE _ReadWriteBarrier (); MemoryBarrier()
186 #define ECB_MEMORY_FENCE_ACQUIRE _ReadWriteBarrier (); MemoryBarrier() /* according to msdn, _ReadBarrier is not a load fence */
187 #define ECB_MEMORY_FENCE_RELEASE _WriteBarrier (); MemoryBarrier()
148 #elif _MSC_VER >= 1400 /* VC++ 2005 */ 188 #elif _MSC_VER >= 1400 /* VC++ 2005 */
149 #pragma intrinsic(_ReadBarrier,_WriteBarrier,_ReadWriteBarrier) 189 #pragma intrinsic(_ReadBarrier,_WriteBarrier,_ReadWriteBarrier)
150 #define ECB_MEMORY_FENCE _ReadWriteBarrier () 190 #define ECB_MEMORY_FENCE _ReadWriteBarrier ()
151 #define ECB_MEMORY_FENCE_ACQUIRE _ReadWriteBarrier () /* according to msdn, _ReadBarrier is not a load fence */ 191 #define ECB_MEMORY_FENCE_ACQUIRE _ReadWriteBarrier () /* according to msdn, _ReadBarrier is not a load fence */
152 #define ECB_MEMORY_FENCE_RELEASE _WriteBarrier () 192 #define ECB_MEMORY_FENCE_RELEASE _WriteBarrier ()
… …
162 #define ECB_MEMORY_FENCE __sync () 202 #define ECB_MEMORY_FENCE __sync ()
163 #endif 203 #endif
164#endif 204#endif
165 205
166#ifndef ECB_MEMORY_FENCE 206#ifndef ECB_MEMORY_FENCE
207 #if ECB_C11 && !defined __STDC_NO_ATOMICS__
208 /* we assume that these memory fences work on all variables/all memory accesses, */
209 /* not just C11 atomics and atomic accesses */
210 #include <stdatomic.h>
211 /* Unfortunately, neither gcc 4.7 nor clang 3.1 generate any instructions for */
212 /* any fence other than seq_cst, which isn't very efficient for us. */
213 /* Why that is, we don't know - either the C11 memory model is quite useless */
214 /* for most usages, or gcc and clang have a bug */
215 /* I *currently* lean towards the latter, and inefficiently implement */
216 /* all three of ecb's fences as a seq_cst fence */
217 #define ECB_MEMORY_FENCE atomic_thread_fence (memory_order_seq_cst)
218 #endif
219#endif
220
221#ifndef ECB_MEMORY_FENCE
167 #if !ECB_AVOID_PTHREADS 222 #if !ECB_AVOID_PTHREADS
168 /* 223 /*
169 * if you get undefined symbol references to pthread_mutex_lock, 224 * if you get undefined symbol references to pthread_mutex_lock,
170 * or failure to find pthread.h, then you should implement 225 * or failure to find pthread.h, then you should implement
171 * the ECB_MEMORY_FENCE operations for your cpu/compiler 226 * the ECB_MEMORY_FENCE operations for your cpu/compiler
… …
443 ecb_inline void ecb_unreachable (void) ecb_noreturn; 498 ecb_inline void ecb_unreachable (void) ecb_noreturn;
444 ecb_inline void ecb_unreachable (void) { } 499 ecb_inline void ecb_unreachable (void) { }
445#endif 500#endif
446 501
447/* try to tell the compiler that some condition is definitely true */ 502/* try to tell the compiler that some condition is definitely true */
448#define ecb_assume(cond) do { if (!(cond)) ecb_unreachable (); } while (0) 503#define ecb_assume(cond) if (!(cond)) ecb_unreachable (); else 0
449 504
450ecb_inline unsigned char ecb_byteorder_helper (void) ecb_const; 505ecb_inline unsigned char ecb_byteorder_helper (void) ecb_const;
451ecb_inline unsigned char 506ecb_inline unsigned char
452ecb_byteorder_helper (void) 507ecb_byteorder_helper (void)
453{ 508{
454 const uint32_t u = 0x11223344; 509 /* the union code still generates code under pressure in gcc, */
455 return *(unsigned char *)&u; 510 /* but less than using pointers, and always seems to */
511 /* successfully return a constant. */
512 /* the reason why we have this horrible preprocessor mess */
513 /* is to avoid it in all cases, at least on common architectures */
514 /* or when using a recent enough gcc version (>= 4.6) */
515#if __i386 || __i386__ || _M_X86 || __amd64 || __amd64__ || _M_X64
516 return 0x44;
517#elif __BYTE_ORDER__ && __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
518 return 0x44;
519#elif __BYTE_ORDER__ && __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
520 return 0x11;
521#else
522 union
523 {
524 uint32_t i;
525 uint8_t c;
526 } u = { 0x11223344 };
527 return u.c;
528#endif
456} 529}
457 530
458ecb_inline ecb_bool ecb_big_endian (void) ecb_const; 531ecb_inline ecb_bool ecb_big_endian (void) ecb_const;
459ecb_inline ecb_bool ecb_big_endian (void) { return ecb_byteorder_helper () == 0x11; } 532ecb_inline ecb_bool ecb_big_endian (void) { return ecb_byteorder_helper () == 0x11; }
460ecb_inline ecb_bool ecb_little_endian (void) ecb_const; 533ecb_inline ecb_bool ecb_little_endian (void) ecb_const;
… …
491 } 564 }
492#else 565#else
493 #define ecb_array_length(name) (sizeof (name) / sizeof (name [0])) 566 #define ecb_array_length(name) (sizeof (name) / sizeof (name [0]))
494#endif 567#endif
495 568
569/*******************************************************************************/
570/* floating point stuff, can be disabled by defining ECB_NO_LIBM */
571
572/* basically, everything uses "ieee pure-endian" floating point numbers */
573/* the only noteworthy exception is ancient armle, which uses order 43218765 */
574#if 0 \
575 || __i386 || __i386__ \
576 || __amd64 || __amd64__ || __x86_64 || __x86_64__ \
577 || __powerpc__ || __ppc__ || __powerpc64__ || __ppc64__ \
578 || defined __arm__ && defined __ARM_EABI__ \
579 || defined __s390__ || defined __s390x__ \
580 || defined __mips__ \
581 || defined __alpha__ \
582 || defined __hppa__ \
583 || defined __ia64__ \
584 || defined __m68k__ \
585 || defined __m88k__ \
586 || defined __sh__ \
587 || defined _M_IX86 || defined _M_AMD64 || defined _M_IA64
588 #define ECB_STDFP 1
589 #include <string.h> /* for memcpy */
590#else
591 #define ECB_STDFP 0
592#endif
593
594#ifndef ECB_NO_LIBM
595
596 #include <math.h> /* for frexp*, ldexp*, INFINITY, NAN */
597
598 /* only the oldest of old doesn't have this one. solaris. */
599 #ifdef INFINITY
600 #define ECB_INFINITY INFINITY
601 #else
602 #define ECB_INFINITY HUGE_VAL
496#endif 603 #endif
497 604
605 #ifdef NAN
606 #define ECB_NAN NAN
607 #else
608 #define ECB_NAN ECB_INFINITY
609 #endif
610
611 /* converts an ieee half/binary16 to a float */
612 ecb_function_ float ecb_binary16_to_float (uint16_t x) ecb_const;
613 ecb_function_ float
614 ecb_binary16_to_float (uint16_t x)
615 {
616 int e = (x >> 10) & 0x1f;
617 int m = x & 0x3ff;
618 float r;
619
620 if (!e ) r = ldexpf (m , -24);
621 else if (e != 31) r = ldexpf (m + 0x400, e - 25);
622 else if (m ) r = ECB_NAN;
623 else r = ECB_INFINITY;
624
625 return x & 0x8000 ? -r : r;
626 }
627
628 /* convert a float to ieee single/binary32 */
629 ecb_function_ uint32_t ecb_float_to_binary32 (float x) ecb_const;
630 ecb_function_ uint32_t
631 ecb_float_to_binary32 (float x)
632 {
633 uint32_t r;
634
635 #if ECB_STDFP
636 memcpy (&r, &x, 4);
637 #else
638 /* slow emulation, works for anything but -0 */
639 uint32_t m;
640 int e;
641
642 if (x == 0e0f ) return 0x00000000U;
643 if (x > +3.40282346638528860e+38f) return 0x7f800000U;
644 if (x < -3.40282346638528860e+38f) return 0xff800000U;
645 if (x != x ) return 0x7fbfffffU;
646
647 m = frexpf (x, &e) * 0x1000000U;
648
649 r = m & 0x80000000U;
650
651 if (r)
652 m = -m;
653
654 if (e <= -126)
655 {
656 m &= 0xffffffU;
657 m >>= (-125 - e);
658 e = -126;
659 }
660
661 r |= (e + 126) << 23;
662 r |= m & 0x7fffffU;
663 #endif
664
665 return r;
666 }
667
668 /* converts an ieee single/binary32 to a float */
669 ecb_function_ float ecb_binary32_to_float (uint32_t x) ecb_const;
670 ecb_function_ float
671 ecb_binary32_to_float (uint32_t x)
672 {
673 float r;
674
675 #if ECB_STDFP
676 memcpy (&r, &x, 4);
677 #else
678 /* emulation, only works for normals and subnormals and +0 */
679 int neg = x >> 31;
680 int e = (x >> 23) & 0xffU;
681
682 x &= 0x7fffffU;
683
684 if (e)
685 x |= 0x800000U;
686 else
687 e = 1;
688
689 /* we distrust ldexpf a bit and do the 2**-24 scaling by an extra multiply */
690 r = ldexpf (x * (0.5f / 0x800000U), e - 126);
691
692 r = neg ? -r : r;
693 #endif
694
695 return r;
696 }
697
698 /* convert a double to ieee double/binary64 */
699 ecb_function_ uint64_t ecb_double_to_binary64 (double x) ecb_const;
700 ecb_function_ uint64_t
701 ecb_double_to_binary64 (double x)
702 {
703 uint64_t r;
704
705 #if ECB_STDFP
706 memcpy (&r, &x, 8);
707 #else
708 /* slow emulation, works for anything but -0 */
709 uint64_t m;
710 int e;
711
712 if (x == 0e0 ) return 0x0000000000000000U;
713 if (x > +1.79769313486231470e+308) return 0x7ff0000000000000U;
714 if (x < -1.79769313486231470e+308) return 0xfff0000000000000U;
715 if (x != x ) return 0X7ff7ffffffffffffU;
716
717 m = frexp (x, &e) * 0x20000000000000U;
718
719 r = m & 0x8000000000000000;;
720
721 if (r)
722 m = -m;
723
724 if (e <= -1022)
725 {
726 m &= 0x1fffffffffffffU;
727 m >>= (-1021 - e);
728 e = -1022;
729 }
730
731 r |= ((uint64_t)(e + 1022)) << 52;
732 r |= m & 0xfffffffffffffU;
733 #endif
734
735 return r;
736 }
737
738 /* converts an ieee double/binary64 to a double */
739 ecb_function_ double ecb_binary64_to_double (uint64_t x) ecb_const;
740 ecb_function_ double
741 ecb_binary64_to_double (uint64_t x)
742 {
743 double r;
744
745 #if ECB_STDFP
746 memcpy (&r, &x, 8);
747 #else
748 /* emulation, only works for normals and subnormals and +0 */
749 int neg = x >> 63;
750 int e = (x >> 52) & 0x7ffU;
751
752 x &= 0xfffffffffffffU;
753
754 if (e)
755 x |= 0x10000000000000U;
756 else
757 e = 1;
758
759 /* we distrust ldexp a bit and do the 2**-53 scaling by an extra multiply */
760 r = ldexp (x * (0.5 / 0x10000000000000U), e - 1022);
761
762 r = neg ? -r : r;
763 #endif
764
765 return r;
766 }
767
768#endif
769
770#endif
771

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