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Comparing libeio/ecb.h (file contents):
Revision 1.11 by root, Tue Apr 24 18:47:50 2012 UTC vs.
Revision 1.17 by root, Fri Dec 28 07:33:41 2012 UTC

… …
28 */ 28 */
29 29
30#ifndef ECB_H 30#ifndef ECB_H
31#define ECB_H 31#define ECB_H
32 32
33/* 16 bits major, 16 bits minor */
34#define ECB_VERSION 0x00010003
35
33#ifdef _WIN32 36#ifdef _WIN32
34 typedef signed char int8_t; 37 typedef signed char int8_t;
35 typedef unsigned char uint8_t; 38 typedef unsigned char uint8_t;
36 typedef signed short int16_t; 39 typedef signed short int16_t;
37 typedef unsigned short uint16_t; 40 typedef unsigned short uint16_t;
… …
42 typedef unsigned long long uint64_t; 45 typedef unsigned long long uint64_t;
43 #else /* _MSC_VER || __BORLANDC__ */ 46 #else /* _MSC_VER || __BORLANDC__ */
44 typedef signed __int64 int64_t; 47 typedef signed __int64 int64_t;
45 typedef unsigned __int64 uint64_t; 48 typedef unsigned __int64 uint64_t;
46 #endif 49 #endif
50 #ifdef _WIN64
51 #define ECB_PTRSIZE 8
52 typedef uint64_t uintptr_t;
53 typedef int64_t intptr_t;
54 #else
55 #define ECB_PTRSIZE 4
56 typedef uint32_t uintptr_t;
57 typedef int32_t intptr_t;
58 #endif
47#else 59#else
48 #include <inttypes.h> 60 #include <inttypes.h>
61 #if UINTMAX_MAX > 0xffffffffU
62 #define ECB_PTRSIZE 8
63 #else
64 #define ECB_PTRSIZE 4
65 #endif
66#endif
67
68/* work around x32 idiocy by defining proper macros */
69#if __x86_64 || _M_AMD64
70 #if __ILP32
71 #define ECB_AMD64_X32 1
72 #else
73 #define ECB_AMD64 1
74 #endif
49#endif 75#endif
50 76
51/* many compilers define _GNUC_ to some versions but then only implement 77/* many compilers define _GNUC_ to some versions but then only implement
52 * what their idiot authors think are the "more important" extensions, 78 * what their idiot authors think are the "more important" extensions,
53 * causing enormous grief in return for some better fake benchmark numbers. 79 * causing enormous grief in return for some better fake benchmark numbers.
… …
61 #else 87 #else
62 #define ECB_GCC_VERSION(major,minor) (__GNUC__ > (major) || (__GNUC__ == (major) && __GNUC_MINOR__ >= (minor))) 88 #define ECB_GCC_VERSION(major,minor) (__GNUC__ > (major) || (__GNUC__ == (major) && __GNUC_MINOR__ >= (minor)))
63 #endif 89 #endif
64#endif 90#endif
65 91
92#define ECB_C (__STDC__+0) /* this assumes that __STDC__ is either empty or a number */
93#define ECB_C99 (__STDC_VERSION__ >= 199901L)
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
107
66/*****************************************************************************/ 108/*****************************************************************************/
67 109
68/* ECB_NO_THREADS - ecb is not used by multiple threads, ever */ 110/* ECB_NO_THREADS - ecb is not used by multiple threads, ever */
69/* 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 */
70 112
71#if ECB_NO_THREADS 113#if ECB_NO_THREADS
72# define ECB_NO_SMP 1 114 #define ECB_NO_SMP 1
73#endif 115#endif
74 116
75#if ECB_NO_THREADS || ECB_NO_SMP 117#if ECB_NO_SMP
76 #define ECB_MEMORY_FENCE do { } while (0) 118 #define ECB_MEMORY_FENCE do { } while (0)
77#endif 119#endif
78 120
79#ifndef ECB_MEMORY_FENCE 121#ifndef ECB_MEMORY_FENCE
80 #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
81 #if __i386 || __i386__ 123 #if __i386 || __i386__
82 #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")
83 #define ECB_MEMORY_FENCE_ACQUIRE ECB_MEMORY_FENCE /* non-lock xchg might be enough */ 125 #define ECB_MEMORY_FENCE_ACQUIRE __asm__ __volatile__ ("" : : : "memory")
84 #define ECB_MEMORY_FENCE_RELEASE do { } while (0) /* unlikely to change in future cpus */ 126 #define ECB_MEMORY_FENCE_RELEASE __asm__ __volatile__ ("")
85 #elif __amd64 || __amd64__ || __x86_64 || __x86_64__ 127 #elif __amd64 || __amd64__ || __x86_64 || __x86_64__
86 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("mfence" : : : "memory") 128 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("mfence" : : : "memory")
87 #define ECB_MEMORY_FENCE_ACQUIRE __asm__ __volatile__ ("lfence" : : : "memory") 129 #define ECB_MEMORY_FENCE_ACQUIRE __asm__ __volatile__ ("" : : : "memory")
88 #define ECB_MEMORY_FENCE_RELEASE __asm__ __volatile__ ("sfence") /* play safe - not needed in any current cpu */ 130 #define ECB_MEMORY_FENCE_RELEASE __asm__ __volatile__ ("")
89 #elif __powerpc__ || __ppc__ || __powerpc64__ || __ppc64__ 131 #elif __powerpc__ || __ppc__ || __powerpc64__ || __ppc64__
90 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("sync" : : : "memory") 132 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("sync" : : : "memory")
91 #elif defined __ARM_ARCH_6__ || defined __ARM_ARCH_6J__ \ 133 #elif defined __ARM_ARCH_6__ || defined __ARM_ARCH_6J__ \
92 || defined __ARM_ARCH_6K__ || defined __ARM_ARCH_6ZK__ 134 || defined __ARM_ARCH_6K__ || defined __ARM_ARCH_6ZK__
93 #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")
94 #elif defined __ARM_ARCH_7__ || defined __ARM_ARCH_7A__ \ 136 #elif defined __ARM_ARCH_7__ || defined __ARM_ARCH_7A__ \
95 || defined __ARM_ARCH_7M__ || defined __ARM_ARCH_7R__ 137 || defined __ARM_ARCH_7M__ || defined __ARM_ARCH_7R__
96 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("dmb" : : : "memory") 138 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("dmb" : : : "memory")
97 #elif __sparc || __sparc__ 139 #elif __sparc || __sparc__
98 #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")
99 #define ECB_MEMORY_FENCE_ACQUIRE __asm__ __volatile__ ("membar #LoadStore | #LoadLoad" : : : "memory") 141 #define ECB_MEMORY_FENCE_ACQUIRE __asm__ __volatile__ ("membar #LoadStore | #LoadLoad" : : : "memory")
100 #define ECB_MEMORY_FENCE_RELEASE __asm__ __volatile__ ("membar #LoadStore | #StoreStore") 142 #define ECB_MEMORY_FENCE_RELEASE __asm__ __volatile__ ("membar #LoadStore | #StoreStore")
101 #elif defined __s390__ || defined __s390x__ 143 #elif defined __s390__ || defined __s390x__
102 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("bcr 15,0" : : : "memory") 144 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("bcr 15,0" : : : "memory")
103 #elif defined __mips__ 145 #elif defined __mips__
104 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("sync" : : : "memory") 146 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("sync" : : : "memory")
105 #elif defined __alpha__ 147 #elif defined __alpha__
106 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("mb" : : : "memory") 148 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("mb" : : : "memory")
149 #elif defined __hppa__
150 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("" : : : "memory")
151 #define ECB_MEMORY_FENCE_RELEASE __asm__ __volatile__ ("")
152 #elif defined __ia64__
153 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("mf" : : : "memory")
107 #endif 154 #endif
108 #endif 155 #endif
109#endif 156#endif
110 157
111#ifndef ECB_MEMORY_FENCE 158#ifndef ECB_MEMORY_FENCE
159 #if ECB_GCC_VERSION(4,7)
160 /* see comment below (stdatomic.h) about the C11 memory model. */
161 #define ECB_MEMORY_FENCE __atomic_thread_fence (__ATOMIC_SEQ_CST)
162
163 /* The __has_feature syntax from clang is so misdesigned that we cannot use it
164 * without risking compile time errors with other compilers. We *could*
165 * define our own ecb_clang_has_feature, but I just can't be bothered to work
166 * around this shit time and again.
167 * #elif defined __clang && __has_feature (cxx_atomic)
168 * // see comment below (stdatomic.h) about the C11 memory model.
169 * #define ECB_MEMORY_FENCE __c11_atomic_thread_fence (__ATOMIC_SEQ_CST)
170 */
171
112 #if ECB_GCC_VERSION(4,4) || defined __INTEL_COMPILER || defined __clang__ 172 #elif ECB_GCC_VERSION(4,4) || defined __INTEL_COMPILER || defined __clang__
113 #define ECB_MEMORY_FENCE __sync_synchronize () 173 #define ECB_MEMORY_FENCE __sync_synchronize ()
114 /*#define ECB_MEMORY_FENCE_ACQUIRE ({ char dummy = 0; __sync_lock_test_and_set (&dummy, 1); }) */
115 /*#define ECB_MEMORY_FENCE_RELEASE ({ char dummy = 1; __sync_lock_release (&dummy ); }) */
116 #elif _MSC_VER >= 1400 /* VC++ 2005 */ 174 #elif _MSC_VER >= 1400 /* VC++ 2005 */
117 #pragma intrinsic(_ReadBarrier,_WriteBarrier,_ReadWriteBarrier) 175 #pragma intrinsic(_ReadBarrier,_WriteBarrier,_ReadWriteBarrier)
118 #define ECB_MEMORY_FENCE _ReadWriteBarrier () 176 #define ECB_MEMORY_FENCE _ReadWriteBarrier ()
119 #define ECB_MEMORY_FENCE_ACQUIRE _ReadWriteBarrier () /* according to msdn, _ReadBarrier is not a load fence */ 177 #define ECB_MEMORY_FENCE_ACQUIRE _ReadWriteBarrier () /* according to msdn, _ReadBarrier is not a load fence */
120 #define ECB_MEMORY_FENCE_RELEASE _WriteBarrier () 178 #define ECB_MEMORY_FENCE_RELEASE _WriteBarrier ()
… …
130 #define ECB_MEMORY_FENCE __sync () 188 #define ECB_MEMORY_FENCE __sync ()
131 #endif 189 #endif
132#endif 190#endif
133 191
134#ifndef ECB_MEMORY_FENCE 192#ifndef ECB_MEMORY_FENCE
193 #if ECB_C11 && !defined __STDC_NO_ATOMICS__
194 /* we assume that these memory fences work on all variables/all memory accesses, */
195 /* not just C11 atomics and atomic accesses */
196 #include <stdatomic.h>
197 /* Unfortunately, neither gcc 4.7 nor clang 3.1 generate any instructions for */
198 /* any fence other than seq_cst, which isn't very efficient for us. */
199 /* Why that is, we don't know - either the C11 memory model is quite useless */
200 /* for most usages, or gcc and clang have a bug */
201 /* I *currently* lean towards the latter, and inefficiently implement */
202 /* all three of ecb's fences as a seq_cst fence */
203 #define ECB_MEMORY_FENCE atomic_thread_fence (memory_order_seq_cst)
204 #endif
205#endif
206
207#ifndef ECB_MEMORY_FENCE
135 #if !ECB_AVOID_PTHREADS 208 #if !ECB_AVOID_PTHREADS
136 /* 209 /*
137 * if you get undefined symbol references to pthread_mutex_lock, 210 * if you get undefined symbol references to pthread_mutex_lock,
138 * or failure to find pthread.h, then you should implement 211 * or failure to find pthread.h, then you should implement
139 * the ECB_MEMORY_FENCE operations for your cpu/compiler 212 * the ECB_MEMORY_FENCE operations for your cpu/compiler
… …
157 #define ECB_MEMORY_FENCE_RELEASE ECB_MEMORY_FENCE 230 #define ECB_MEMORY_FENCE_RELEASE ECB_MEMORY_FENCE
158#endif 231#endif
159 232
160/*****************************************************************************/ 233/*****************************************************************************/
161 234
162#define ECB_C99 (__STDC_VERSION__ >= 199901L)
163
164#if __cplusplus 235#if __cplusplus
165 #define ecb_inline static inline 236 #define ecb_inline static inline
166#elif ECB_GCC_VERSION(2,5) 237#elif ECB_GCC_VERSION(2,5)
167 #define ecb_inline static __inline__ 238 #define ecb_inline static __inline__
168#elif ECB_C99 239#elif ECB_C99
… …
206#elif ECB_GCC_VERSION(3,0) 277#elif ECB_GCC_VERSION(3,0)
207 #define ecb_decltype(x) __typeof(x) 278 #define ecb_decltype(x) __typeof(x)
208#endif 279#endif
209 280
210#define ecb_noinline ecb_attribute ((__noinline__)) 281#define ecb_noinline ecb_attribute ((__noinline__))
211#define ecb_noreturn ecb_attribute ((__noreturn__))
212#define ecb_unused ecb_attribute ((__unused__)) 282#define ecb_unused ecb_attribute ((__unused__))
213#define ecb_const ecb_attribute ((__const__)) 283#define ecb_const ecb_attribute ((__const__))
214#define ecb_pure ecb_attribute ((__pure__)) 284#define ecb_pure ecb_attribute ((__pure__))
285
286#if ECB_C11
287 #define ecb_noreturn _Noreturn
288#else
289 #define ecb_noreturn ecb_attribute ((__noreturn__))
290#endif
215 291
216#if ECB_GCC_VERSION(4,3) 292#if ECB_GCC_VERSION(4,3)
217 #define ecb_artificial ecb_attribute ((__artificial__)) 293 #define ecb_artificial ecb_attribute ((__artificial__))
218 #define ecb_hot ecb_attribute ((__hot__)) 294 #define ecb_hot ecb_attribute ((__hot__))
219 #define ecb_cold ecb_attribute ((__cold__)) 295 #define ecb_cold ecb_attribute ((__cold__))
… …
310 386
311 return r + ecb_ld32 (x); 387 return r + ecb_ld32 (x);
312 } 388 }
313#endif 389#endif
314 390
391ecb_function_ ecb_bool ecb_is_pot32 (uint32_t x) ecb_const;
392ecb_function_ ecb_bool ecb_is_pot32 (uint32_t x) { return !(x & (x - 1)); }
393ecb_function_ ecb_bool ecb_is_pot64 (uint64_t x) ecb_const;
394ecb_function_ ecb_bool ecb_is_pot64 (uint64_t x) { return !(x & (x - 1)); }
395
315ecb_function_ uint8_t ecb_bitrev8 (uint8_t x) ecb_const; 396ecb_function_ uint8_t ecb_bitrev8 (uint8_t x) ecb_const;
316ecb_function_ uint8_t ecb_bitrev8 (uint8_t x) 397ecb_function_ uint8_t ecb_bitrev8 (uint8_t x)
317{ 398{
318 return ( (x * 0x0802U & 0x22110U) 399 return ( (x * 0x0802U & 0x22110U)
319 | (x * 0x8020U & 0x88440U)) * 0x10101U >> 16; 400 | (x * 0x8020U & 0x88440U)) * 0x10101U >> 16;
… …
403 ecb_inline void ecb_unreachable (void) ecb_noreturn; 484 ecb_inline void ecb_unreachable (void) ecb_noreturn;
404 ecb_inline void ecb_unreachable (void) { } 485 ecb_inline void ecb_unreachable (void) { }
405#endif 486#endif
406 487
407/* try to tell the compiler that some condition is definitely true */ 488/* try to tell the compiler that some condition is definitely true */
408#define ecb_assume(cond) do { if (!(cond)) ecb_unreachable (); } while (0) 489#define ecb_assume(cond) if (!(cond)) ecb_unreachable (); else 0
409 490
410ecb_inline unsigned char ecb_byteorder_helper (void) ecb_const; 491ecb_inline unsigned char ecb_byteorder_helper (void) ecb_const;
411ecb_inline unsigned char 492ecb_inline unsigned char
412ecb_byteorder_helper (void) 493ecb_byteorder_helper (void)
413{ 494{
414 const uint32_t u = 0x11223344; 495 /* the union code still generates code under pressure in gcc, */
415 return *(unsigned char *)&u; 496 /* but less than using pointers, and always seems to */
497 /* successfully return a constant. */
498 /* the reason why we have this horrible preprocessor mess */
499 /* is to avoid it in all cases, at least on common architectures */
500 /* or when using a recent enough gcc version (>= 4.6) */
501#if __i386 || __i386__ || _M_X86 || __amd64 || __amd64__ || _M_X64
502 return 0x44;
503#elif __BYTE_ORDER__ && __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
504 return 0x44;
505#elif __BYTE_ORDER__ && __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
506 return 0x11;
507#else
508 union
509 {
510 uint32_t i;
511 uint8_t c;
512 } u = { 0x11223344 };
513 return u.c;
514#endif
416} 515}
417 516
418ecb_inline ecb_bool ecb_big_endian (void) ecb_const; 517ecb_inline ecb_bool ecb_big_endian (void) ecb_const;
419ecb_inline ecb_bool ecb_big_endian (void) { return ecb_byteorder_helper () == 0x11; } 518ecb_inline ecb_bool ecb_big_endian (void) { return ecb_byteorder_helper () == 0x11; }
420ecb_inline ecb_bool ecb_little_endian (void) ecb_const; 519ecb_inline ecb_bool ecb_little_endian (void) ecb_const;
… …
451 } 550 }
452#else 551#else
453 #define ecb_array_length(name) (sizeof (name) / sizeof (name [0])) 552 #define ecb_array_length(name) (sizeof (name) / sizeof (name [0]))
454#endif 553#endif
455 554
555/*******************************************************************************/
556/* floating point stuff, can be disabled by defining ECB_NO_LIBM */
557
558/* basically, everything uses "ieee pure-endian" floating point numbers */
559/* the only noteworthy exception is ancient armle, which uses order 43218765 */
560#if 0 \
561 || __i386 || __i386__ \
562 || __amd64 || __amd64__ || __x86_64 || __x86_64__ \
563 || __powerpc__ || __ppc__ || __powerpc64__ || __ppc64__ \
564 || defined __arm__ && defined __ARM_EABI__ \
565 || defined __s390__ || defined __s390x__ \
566 || defined __mips__ \
567 || defined __alpha__ \
568 || defined __hppa__ \
569 || defined __ia64__ \
570 || defined _M_IX86 || defined _M_AMD64 || defined _M_IA64
571 #define ECB_STDFP 1
572 #include <string.h> /* for memcpy */
573#else
574 #define ECB_STDFP 0
575 #include <math.h> /* for frexp*, ldexp* */
576#endif
577
578#ifndef ECB_NO_LIBM
579
580 /* convert a float to ieee single/binary32 */
581 ecb_function_ uint32_t ecb_float_to_binary32 (float x) ecb_const;
582 ecb_function_ uint32_t
583 ecb_float_to_binary32 (float x)
584 {
585 uint32_t r;
586
587 #if ECB_STDFP
588 memcpy (&r, &x, 4);
589 #else
590 /* slow emulation, works for anything but -0 */
591 uint32_t m;
592 int e;
593
594 if (x == 0e0f ) return 0x00000000U;
595 if (x > +3.40282346638528860e+38f) return 0x7f800000U;
596 if (x < -3.40282346638528860e+38f) return 0xff800000U;
597 if (x != x ) return 0x7fbfffffU;
598
599 m = frexpf (x, &e) * 0x1000000U;
600
601 r = m & 0x80000000U;
602
603 if (r)
604 m = -m;
605
606 if (e <= -126)
607 {
608 m &= 0xffffffU;
609 m >>= (-125 - e);
610 e = -126;
611 }
612
613 r |= (e + 126) << 23;
614 r |= m & 0x7fffffU;
456#endif 615 #endif
457 616
617 return r;
618 }
619
620 /* converts an ieee single/binary32 to a float */
621 ecb_function_ float ecb_binary32_to_float (uint32_t x) ecb_const;
622 ecb_function_ float
623 ecb_binary32_to_float (uint32_t x)
624 {
625 float r;
626
627 #if ECB_STDFP
628 memcpy (&r, &x, 4);
629 #else
630 /* emulation, only works for normals and subnormals and +0 */
631 int neg = x >> 31;
632 int e = (x >> 23) & 0xffU;
633
634 x &= 0x7fffffU;
635
636 if (e)
637 x |= 0x800000U;
638 else
639 e = 1;
640
641 /* we distrust ldexpf a bit and do the 2**-24 scaling by an extra multiply */
642 r = ldexpf (x * (0.5f / 0x800000U), e - 126);
643
644 r = neg ? -r : r;
645 #endif
646
647 return r;
648 }
649
650 /* convert a double to ieee double/binary64 */
651 ecb_function_ uint64_t ecb_double_to_binary64 (double x) ecb_const;
652 ecb_function_ uint64_t
653 ecb_double_to_binary64 (double x)
654 {
655 uint64_t r;
656
657 #if ECB_STDFP
658 memcpy (&r, &x, 8);
659 #else
660 /* slow emulation, works for anything but -0 */
661 uint64_t m;
662 int e;
663
664 if (x == 0e0 ) return 0x0000000000000000U;
665 if (x > +1.79769313486231470e+308) return 0x7ff0000000000000U;
666 if (x < -1.79769313486231470e+308) return 0xfff0000000000000U;
667 if (x != x ) return 0X7ff7ffffffffffffU;
668
669 m = frexp (x, &e) * 0x20000000000000U;
670
671 r = m & 0x8000000000000000;;
672
673 if (r)
674 m = -m;
675
676 if (e <= -1022)
677 {
678 m &= 0x1fffffffffffffU;
679 m >>= (-1021 - e);
680 e = -1022;
681 }
682
683 r |= ((uint64_t)(e + 1022)) << 52;
684 r |= m & 0xfffffffffffffU;
685 #endif
686
687 return r;
688 }
689
690 /* converts an ieee double/binary64 to a double */
691 ecb_function_ double ecb_binary64_to_double (uint64_t x) ecb_const;
692 ecb_function_ double
693 ecb_binary64_to_double (uint64_t x)
694 {
695 double r;
696
697 #if ECB_STDFP
698 memcpy (&r, &x, 8);
699 #else
700 /* emulation, only works for normals and subnormals and +0 */
701 int neg = x >> 63;
702 int e = (x >> 52) & 0x7ffU;
703
704 x &= 0xfffffffffffffU;
705
706 if (e)
707 x |= 0x10000000000000U;
708 else
709 e = 1;
710
711 /* we distrust ldexp a bit and do the 2**-53 scaling by an extra multiply */
712 r = ldexp (x * (0.5 / 0x10000000000000U), e - 1022);
713
714 r = neg ? -r : r;
715 #endif
716
717 return r;
718 }
719
720#endif
721
722#endif
723

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