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Comparing libeio/ecb.h (file contents):
Revision 1.13 by root, Sat Jun 2 20:13:26 2012 UTC vs.
Revision 1.21 by root, Fri May 16 15:15:23 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 (©) 2009-2014 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:
… …
23 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; 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, 24 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
25 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTH- 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 26 * ERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
27 * OF THE POSSIBILITY OF SUCH DAMAGE. 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.
28 */ 39 */
29 40
30#ifndef ECB_H 41#ifndef ECB_H
31#define ECB_H 42#define ECB_H
32 43
33/* 16 bits major, 16 bits minor */ 44/* 16 bits major, 16 bits minor */
34#define ECB_VERSION 0x00010001 45#define ECB_VERSION 0x00010003
35 46
36#ifdef _WIN32 47#ifdef _WIN32
37 typedef signed char int8_t; 48 typedef signed char int8_t;
38 typedef unsigned char uint8_t; 49 typedef unsigned char uint8_t;
39 typedef signed short int16_t; 50 typedef signed short int16_t;
… …
54 #else 65 #else
55 #define ECB_PTRSIZE 4 66 #define ECB_PTRSIZE 4
56 typedef uint32_t uintptr_t; 67 typedef uint32_t uintptr_t;
57 typedef int32_t intptr_t; 68 typedef int32_t intptr_t;
58 #endif 69 #endif
59 typedef intptr_t ptrdiff_t;
60#else 70#else
61 #include <inttypes.h> 71 #include <inttypes.h>
62 #if UINTMAX_MAX > 0xffffffffU 72 #if UINTMAX_MAX > 0xffffffffU
63 #define ECB_PTRSIZE 8 73 #define ECB_PTRSIZE 8
64 #else 74 #else
65 #define ECB_PTRSIZE 4 75 #define ECB_PTRSIZE 4
76 #endif
77#endif
78
79/* work around x32 idiocy by defining proper macros */
80#if __amd64 || __x86_64 || _M_AMD64 || _M_X64
81 #if _ILP32
82 #define ECB_AMD64_X32 1
83 #else
84 #define ECB_AMD64 1
66 #endif 85 #endif
67#endif 86#endif
68 87
69/* many compilers define _GNUC_ to some versions but then only implement 88/* many compilers define _GNUC_ to some versions but then only implement
70 * what their idiot authors think are the "more important" extensions, 89 * what their idiot authors think are the "more important" extensions,
… …
79 #else 98 #else
80 #define ECB_GCC_VERSION(major,minor) (__GNUC__ > (major) || (__GNUC__ == (major) && __GNUC_MINOR__ >= (minor))) 99 #define ECB_GCC_VERSION(major,minor) (__GNUC__ > (major) || (__GNUC__ == (major) && __GNUC_MINOR__ >= (minor)))
81 #endif 100 #endif
82#endif 101#endif
83 102
84#define ECB_C (__STDC__+0) /* this assumes that __STDC__ is either empty or a number */
85#define ECB_C99 (__STDC_VERSION__ >= 199901L)
86#define ECB_C11 (__STDC_VERSION__ >= 201112L)
87#define ECB_CPP (__cplusplus+0) 103#define ECB_CPP (__cplusplus+0)
88#define ECB_CPP11 (__cplusplus >= 201103L) 104#define ECB_CPP11 (__cplusplus >= 201103L)
105
106#if ECB_CPP
107 #define ECB_C 0
108 #define ECB_STDC_VERSION 0
109#else
110 #define ECB_C 1
111 #define ECB_STDC_VERSION __STDC_VERSION__
112#endif
113
114#define ECB_C99 (ECB_STDC_VERSION >= 199901L)
115#define ECB_C11 (ECB_STDC_VERSION >= 201112L)
116
117#if ECB_CPP
118 #define ECB_EXTERN_C extern "C"
119 #define ECB_EXTERN_C_BEG ECB_EXTERN_C {
120 #define ECB_EXTERN_C_END }
121#else
122 #define ECB_EXTERN_C extern
123 #define ECB_EXTERN_C_BEG
124 #define ECB_EXTERN_C_END
125#endif
89 126
90/*****************************************************************************/ 127/*****************************************************************************/
91 128
92/* ECB_NO_THREADS - ecb is not used by multiple threads, ever */ 129/* ECB_NO_THREADS - ecb is not used by multiple threads, ever */
93/* ECB_NO_SMP - ecb might be used in multiple threads, but only on a single cpu */ 130/* ECB_NO_SMP - ecb might be used in multiple threads, but only on a single cpu */
… …
116 || defined __ARM_ARCH_6K__ || defined __ARM_ARCH_6ZK__ 153 || defined __ARM_ARCH_6K__ || defined __ARM_ARCH_6ZK__
117 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("mcr p15,0,%0,c7,c10,5" : : "r" (0) : "memory") 154 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("mcr p15,0,%0,c7,c10,5" : : "r" (0) : "memory")
118 #elif defined __ARM_ARCH_7__ || defined __ARM_ARCH_7A__ \ 155 #elif defined __ARM_ARCH_7__ || defined __ARM_ARCH_7A__ \
119 || defined __ARM_ARCH_7M__ || defined __ARM_ARCH_7R__ 156 || defined __ARM_ARCH_7M__ || defined __ARM_ARCH_7R__
120 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("dmb" : : : "memory") 157 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("dmb" : : : "memory")
158 #elif __aarch64__
159 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("dmb ish" : : : "memory")
121 #elif __sparc || __sparc__ 160 #elif (__sparc || __sparc__) && !__sparcv8
122 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("membar #LoadStore | #LoadLoad | #StoreStore | #StoreLoad" : : : "memory") 161 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("membar #LoadStore | #LoadLoad | #StoreStore | #StoreLoad" : : : "memory")
123 #define ECB_MEMORY_FENCE_ACQUIRE __asm__ __volatile__ ("membar #LoadStore | #LoadLoad" : : : "memory") 162 #define ECB_MEMORY_FENCE_ACQUIRE __asm__ __volatile__ ("membar #LoadStore | #LoadLoad" : : : "memory")
124 #define ECB_MEMORY_FENCE_RELEASE __asm__ __volatile__ ("membar #LoadStore | #StoreStore") 163 #define ECB_MEMORY_FENCE_RELEASE __asm__ __volatile__ ("membar #LoadStore | #StoreStore")
125 #elif defined __s390__ || defined __s390x__ 164 #elif defined __s390__ || defined __s390x__
126 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("bcr 15,0" : : : "memory") 165 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("bcr 15,0" : : : "memory")
127 #elif defined __mips__ 166 #elif defined __mips__
167 /* GNU/Linux emulates sync on mips1 architectures, so we force its use */
168 /* anybody else who still uses mips1 is supposed to send in their version, with detection code. */
128 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("sync" : : : "memory") 169 #define ECB_MEMORY_FENCE __asm__ __volatile__ (".set mips2; sync; .set mips0" : : : "memory")
129 #elif defined __alpha__ 170 #elif defined __alpha__
130 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("mb" : : : "memory") 171 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("mb" : : : "memory")
131 #elif defined __hppa__ 172 #elif defined __hppa__
132 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("" : : : "memory") 173 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("" : : : "memory")
133 #define ECB_MEMORY_FENCE_RELEASE __asm__ __volatile__ ("") 174 #define ECB_MEMORY_FENCE_RELEASE __asm__ __volatile__ ("")
134 #elif defined __ia64__ 175 #elif defined __ia64__
135 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("mf" : : : "memory") 176 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("mf" : : : "memory")
177 #elif defined __m68k__
178 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("" : : : "memory")
179 #elif defined __m88k__
180 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("tb1 0,%%r0,128" : : : "memory")
181 #elif defined __sh__
182 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("" : : : "memory")
136 #endif 183 #endif
137 #endif 184 #endif
138#endif 185#endif
139 186
140#ifndef ECB_MEMORY_FENCE 187#ifndef ECB_MEMORY_FENCE
141 #if ECB_GCC_VERSION(4,7) 188 #if ECB_GCC_VERSION(4,7)
142 /* see comment below (stdatomic.h) about the C11 memory model. */ 189 /* see comment below (stdatomic.h) about the C11 memory model. */
143 #define ECB_MEMORY_FENCE __atomic_thread_fence (__ATOMIC_SEQ_CST) 190 #define ECB_MEMORY_FENCE __atomic_thread_fence (__ATOMIC_SEQ_CST)
191 #define ECB_MEMORY_FENCE_ACQUIRE __atomic_thread_fence (__ATOMIC_ACQUIRE)
192 #define ECB_MEMORY_FENCE_RELEASE __atomic_thread_fence (__ATOMIC_RELEASE)
193
194 /* The __has_feature syntax from clang is so misdesigned that we cannot use it
195 * without risking compile time errors with other compilers. We *could*
196 * define our own ecb_clang_has_feature, but I just can't be bothered to work
197 * around this shit time and again.
144 #elif defined __clang && __has_feature (cxx_atomic) 198 * #elif defined __clang && __has_feature (cxx_atomic)
145 /* see comment below (stdatomic.h) about the C11 memory model. */ 199 * // see comment below (stdatomic.h) about the C11 memory model.
146 #define ECB_MEMORY_FENCE __c11_atomic_thread_fence (__ATOMIC_SEQ_CST) 200 * #define ECB_MEMORY_FENCE __c11_atomic_thread_fence (__ATOMIC_SEQ_CST)
201 * #define ECB_MEMORY_FENCE_ACQUIRE __c11_atomic_thread_fence (__ATOMIC_ACQUIRE)
202 * #define ECB_MEMORY_FENCE_RELEASE __c11_atomic_thread_fence (__ATOMIC_RELEASE)
203 */
204
147 #elif ECB_GCC_VERSION(4,4) || defined __INTEL_COMPILER || defined __clang__ 205 #elif ECB_GCC_VERSION(4,4) || defined __INTEL_COMPILER || defined __clang__
148 #define ECB_MEMORY_FENCE __sync_synchronize () 206 #define ECB_MEMORY_FENCE __sync_synchronize ()
207 #elif _MSC_VER >= 1500 /* VC++ 2008 */
208 /* apparently, microsoft broke all the memory barrier stuff in Visual Studio 2008... */
209 #pragma intrinsic(_ReadBarrier,_WriteBarrier,_ReadWriteBarrier)
210 #define ECB_MEMORY_FENCE _ReadWriteBarrier (); MemoryBarrier()
211 #define ECB_MEMORY_FENCE_ACQUIRE _ReadWriteBarrier (); MemoryBarrier() /* according to msdn, _ReadBarrier is not a load fence */
212 #define ECB_MEMORY_FENCE_RELEASE _WriteBarrier (); MemoryBarrier()
149 #elif _MSC_VER >= 1400 /* VC++ 2005 */ 213 #elif _MSC_VER >= 1400 /* VC++ 2005 */
150 #pragma intrinsic(_ReadBarrier,_WriteBarrier,_ReadWriteBarrier) 214 #pragma intrinsic(_ReadBarrier,_WriteBarrier,_ReadWriteBarrier)
151 #define ECB_MEMORY_FENCE _ReadWriteBarrier () 215 #define ECB_MEMORY_FENCE _ReadWriteBarrier ()
152 #define ECB_MEMORY_FENCE_ACQUIRE _ReadWriteBarrier () /* according to msdn, _ReadBarrier is not a load fence */ 216 #define ECB_MEMORY_FENCE_ACQUIRE _ReadWriteBarrier () /* according to msdn, _ReadBarrier is not a load fence */
153 #define ECB_MEMORY_FENCE_RELEASE _WriteBarrier () 217 #define ECB_MEMORY_FENCE_RELEASE _WriteBarrier ()
… …
173 /* any fence other than seq_cst, which isn't very efficient for us. */ 237 /* any fence other than seq_cst, which isn't very efficient for us. */
174 /* Why that is, we don't know - either the C11 memory model is quite useless */ 238 /* Why that is, we don't know - either the C11 memory model is quite useless */
175 /* for most usages, or gcc and clang have a bug */ 239 /* for most usages, or gcc and clang have a bug */
176 /* I *currently* lean towards the latter, and inefficiently implement */ 240 /* I *currently* lean towards the latter, and inefficiently implement */
177 /* all three of ecb's fences as a seq_cst fence */ 241 /* all three of ecb's fences as a seq_cst fence */
242 /* Update, gcc-4.8 generates mfence for all c++ fences, but nothing */
243 /* for all __atomic_thread_fence's except seq_cst */
178 #define ECB_MEMORY_FENCE atomic_thread_fence (memory_order_seq_cst) 244 #define ECB_MEMORY_FENCE atomic_thread_fence (memory_order_seq_cst)
179 #endif 245 #endif
180#endif 246#endif
181 247
182#ifndef ECB_MEMORY_FENCE 248#ifndef ECB_MEMORY_FENCE
… …
239 #define ecb_is_constant(expr) __builtin_constant_p (expr) 305 #define ecb_is_constant(expr) __builtin_constant_p (expr)
240 #define ecb_expect(expr,value) __builtin_expect ((expr),(value)) 306 #define ecb_expect(expr,value) __builtin_expect ((expr),(value))
241 #define ecb_prefetch(addr,rw,locality) __builtin_prefetch (addr, rw, locality) 307 #define ecb_prefetch(addr,rw,locality) __builtin_prefetch (addr, rw, locality)
242#else 308#else
243 #define ecb_attribute(attrlist) 309 #define ecb_attribute(attrlist)
310
311 /* possible C11 impl for integral types
312 typedef struct ecb_is_constant_struct ecb_is_constant_struct;
313 #define ecb_is_constant(expr) _Generic ((1 ? (struct ecb_is_constant_struct *)0 : (void *)((expr) - (expr)), ecb_is_constant_struct *: 0, default: 1)) */
314
244 #define ecb_is_constant(expr) 0 315 #define ecb_is_constant(expr) 0
245 #define ecb_expect(expr,value) (expr) 316 #define ecb_expect(expr,value) (expr)
246 #define ecb_prefetch(addr,rw,locality) 317 #define ecb_prefetch(addr,rw,locality)
247#endif 318#endif
248 319
… …
459 ecb_inline void ecb_unreachable (void) ecb_noreturn; 530 ecb_inline void ecb_unreachable (void) ecb_noreturn;
460 ecb_inline void ecb_unreachable (void) { } 531 ecb_inline void ecb_unreachable (void) { }
461#endif 532#endif
462 533
463/* try to tell the compiler that some condition is definitely true */ 534/* try to tell the compiler that some condition is definitely true */
464#define ecb_assume(cond) do { if (!(cond)) ecb_unreachable (); } while (0) 535#define ecb_assume(cond) if (!(cond)) ecb_unreachable (); else 0
465 536
466ecb_inline unsigned char ecb_byteorder_helper (void) ecb_const; 537ecb_inline unsigned char ecb_byteorder_helper (void) ecb_const;
467ecb_inline unsigned char 538ecb_inline unsigned char
468ecb_byteorder_helper (void) 539ecb_byteorder_helper (void)
469{ 540{
470 const uint32_t u = 0x11223344; 541 /* the union code still generates code under pressure in gcc, */
471 return *(unsigned char *)&u; 542 /* but less than using pointers, and always seems to */
543 /* successfully return a constant. */
544 /* the reason why we have this horrible preprocessor mess */
545 /* is to avoid it in all cases, at least on common architectures */
546 /* or when using a recent enough gcc version (>= 4.6) */
547#if __i386 || __i386__ || _M_X86 || __amd64 || __amd64__ || _M_X64
548 return 0x44;
549#elif __BYTE_ORDER__ && __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
550 return 0x44;
551#elif __BYTE_ORDER__ && __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
552 return 0x11;
553#else
554 union
555 {
556 uint32_t i;
557 uint8_t c;
558 } u = { 0x11223344 };
559 return u.c;
560#endif
472} 561}
473 562
474ecb_inline ecb_bool ecb_big_endian (void) ecb_const; 563ecb_inline ecb_bool ecb_big_endian (void) ecb_const;
475ecb_inline ecb_bool ecb_big_endian (void) { return ecb_byteorder_helper () == 0x11; } 564ecb_inline ecb_bool ecb_big_endian (void) { return ecb_byteorder_helper () == 0x11; }
476ecb_inline ecb_bool ecb_little_endian (void) ecb_const; 565ecb_inline ecb_bool ecb_little_endian (void) ecb_const;
… …
507 } 596 }
508#else 597#else
509 #define ecb_array_length(name) (sizeof (name) / sizeof (name [0])) 598 #define ecb_array_length(name) (sizeof (name) / sizeof (name [0]))
510#endif 599#endif
511 600
601/*******************************************************************************/
602/* floating point stuff, can be disabled by defining ECB_NO_LIBM */
603
604/* basically, everything uses "ieee pure-endian" floating point numbers */
605/* the only noteworthy exception is ancient armle, which uses order 43218765 */
606#if 0 \
607 || __i386 || __i386__ \
608 || __amd64 || __amd64__ || __x86_64 || __x86_64__ \
609 || __powerpc__ || __ppc__ || __powerpc64__ || __ppc64__ \
610 || defined __s390__ || defined __s390x__ \
611 || defined __mips__ \
612 || defined __alpha__ \
613 || defined __hppa__ \
614 || defined __ia64__ \
615 || defined __m68k__ \
616 || defined __m88k__ \
617 || defined __sh__ \
618 || defined _M_IX86 || defined _M_AMD64 || defined _M_IA64 \
619 || (defined __arm__ && (defined __ARM_EABI__ || defined __EABI__ || defined __VFP_FP__ || defined _WIN32_WCE || defined __ANDROID__)) \
620 || defined __aarch64__
621 #define ECB_STDFP 1
622 #include <string.h> /* for memcpy */
623#else
624 #define ECB_STDFP 0
625#endif
626
627#ifndef ECB_NO_LIBM
628
629 #include <math.h> /* for frexp*, ldexp*, INFINITY, NAN */
630
631 /* only the oldest of old doesn't have this one. solaris. */
632 #ifdef INFINITY
633 #define ECB_INFINITY INFINITY
634 #else
635 #define ECB_INFINITY HUGE_VAL
512#endif 636 #endif
513 637
638 #ifdef NAN
639 #define ECB_NAN NAN
640 #else
641 #define ECB_NAN ECB_INFINITY
642 #endif
643
644 /* converts an ieee half/binary16 to a float */
645 ecb_function_ float ecb_binary16_to_float (uint16_t x) ecb_const;
646 ecb_function_ float
647 ecb_binary16_to_float (uint16_t x)
648 {
649 int e = (x >> 10) & 0x1f;
650 int m = x & 0x3ff;
651 float r;
652
653 if (!e ) r = ldexpf (m , -24);
654 else if (e != 31) r = ldexpf (m + 0x400, e - 25);
655 else if (m ) r = ECB_NAN;
656 else r = ECB_INFINITY;
657
658 return x & 0x8000 ? -r : r;
659 }
660
661 /* convert a float to ieee single/binary32 */
662 ecb_function_ uint32_t ecb_float_to_binary32 (float x) ecb_const;
663 ecb_function_ uint32_t
664 ecb_float_to_binary32 (float x)
665 {
666 uint32_t r;
667
668 #if ECB_STDFP
669 memcpy (&r, &x, 4);
670 #else
671 /* slow emulation, works for anything but -0 */
672 uint32_t m;
673 int e;
674
675 if (x == 0e0f ) return 0x00000000U;
676 if (x > +3.40282346638528860e+38f) return 0x7f800000U;
677 if (x < -3.40282346638528860e+38f) return 0xff800000U;
678 if (x != x ) return 0x7fbfffffU;
679
680 m = frexpf (x, &e) * 0x1000000U;
681
682 r = m & 0x80000000U;
683
684 if (r)
685 m = -m;
686
687 if (e <= -126)
688 {
689 m &= 0xffffffU;
690 m >>= (-125 - e);
691 e = -126;
692 }
693
694 r |= (e + 126) << 23;
695 r |= m & 0x7fffffU;
696 #endif
697
698 return r;
699 }
700
701 /* converts an ieee single/binary32 to a float */
702 ecb_function_ float ecb_binary32_to_float (uint32_t x) ecb_const;
703 ecb_function_ float
704 ecb_binary32_to_float (uint32_t x)
705 {
706 float r;
707
708 #if ECB_STDFP
709 memcpy (&r, &x, 4);
710 #else
711 /* emulation, only works for normals and subnormals and +0 */
712 int neg = x >> 31;
713 int e = (x >> 23) & 0xffU;
714
715 x &= 0x7fffffU;
716
717 if (e)
718 x |= 0x800000U;
719 else
720 e = 1;
721
722 /* we distrust ldexpf a bit and do the 2**-24 scaling by an extra multiply */
723 r = ldexpf (x * (0.5f / 0x800000U), e - 126);
724
725 r = neg ? -r : r;
726 #endif
727
728 return r;
729 }
730
731 /* convert a double to ieee double/binary64 */
732 ecb_function_ uint64_t ecb_double_to_binary64 (double x) ecb_const;
733 ecb_function_ uint64_t
734 ecb_double_to_binary64 (double x)
735 {
736 uint64_t r;
737
738 #if ECB_STDFP
739 memcpy (&r, &x, 8);
740 #else
741 /* slow emulation, works for anything but -0 */
742 uint64_t m;
743 int e;
744
745 if (x == 0e0 ) return 0x0000000000000000U;
746 if (x > +1.79769313486231470e+308) return 0x7ff0000000000000U;
747 if (x < -1.79769313486231470e+308) return 0xfff0000000000000U;
748 if (x != x ) return 0X7ff7ffffffffffffU;
749
750 m = frexp (x, &e) * 0x20000000000000U;
751
752 r = m & 0x8000000000000000;;
753
754 if (r)
755 m = -m;
756
757 if (e <= -1022)
758 {
759 m &= 0x1fffffffffffffU;
760 m >>= (-1021 - e);
761 e = -1022;
762 }
763
764 r |= ((uint64_t)(e + 1022)) << 52;
765 r |= m & 0xfffffffffffffU;
766 #endif
767
768 return r;
769 }
770
771 /* converts an ieee double/binary64 to a double */
772 ecb_function_ double ecb_binary64_to_double (uint64_t x) ecb_const;
773 ecb_function_ double
774 ecb_binary64_to_double (uint64_t x)
775 {
776 double r;
777
778 #if ECB_STDFP
779 memcpy (&r, &x, 8);
780 #else
781 /* emulation, only works for normals and subnormals and +0 */
782 int neg = x >> 63;
783 int e = (x >> 52) & 0x7ffU;
784
785 x &= 0xfffffffffffffU;
786
787 if (e)
788 x |= 0x10000000000000U;
789 else
790 e = 1;
791
792 /* we distrust ldexp a bit and do the 2**-53 scaling by an extra multiply */
793 r = ldexp (x * (0.5 / 0x10000000000000U), e - 1022);
794
795 r = neg ? -r : r;
796 #endif
797
798 return r;
799 }
800
801#endif
802
803#endif
804

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