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Comparing libecb/ecb.h (file contents):
Revision 1.102 by root, Thu Jun 28 17:23:58 2012 UTC vs.
Revision 1.130 by root, Fri Mar 21 16:40:45 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:
… …
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;
… …
63 #else 63 #else
64 #define ECB_PTRSIZE 4 64 #define ECB_PTRSIZE 4
65 #endif 65 #endif
66#endif 66#endif
67 67
68/* work around x32 idiocy by defining proper macros */
69#if __amd64 || __x86_64 || _M_AMD64 || _M_X64
70 #if _ILP32
71 #define ECB_AMD64_X32 1
72 #else
73 #define ECB_AMD64 1
74 #endif
75#endif
76
68/* many compilers define _GNUC_ to some versions but then only implement 77/* many compilers define _GNUC_ to some versions but then only implement
69 * what their idiot authors think are the "more important" extensions, 78 * what their idiot authors think are the "more important" extensions,
70 * causing enormous grief in return for some better fake benchmark numbers. 79 * causing enormous grief in return for some better fake benchmark numbers.
71 * or so. 80 * or so.
72 * we try to detect these and simply assume they are not gcc - if they have 81 * we try to detect these and simply assume they are not gcc - if they have
… …
78 #else 87 #else
79 #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)))
80 #endif 89 #endif
81#endif 90#endif
82 91
83#define ECB_C (__STDC__+0) /* this assumes that __STDC__ is either empty or a number */
84#define ECB_C99 (__STDC_VERSION__ >= 199901L)
85#define ECB_C11 (__STDC_VERSION__ >= 201112L)
86#define ECB_CPP (__cplusplus+0) 92#define ECB_CPP (__cplusplus+0)
87#define ECB_CPP11 (__cplusplus >= 201103L) 93#define ECB_CPP11 (__cplusplus >= 201103L)
94
95#if ECB_CPP
96 #define ECB_C 0
97 #define ECB_STDC_VERSION 0
98#else
99 #define ECB_C 1
100 #define ECB_STDC_VERSION __STDC_VERSION__
101#endif
102
103#define ECB_C99 (ECB_STDC_VERSION >= 199901L)
104#define ECB_C11 (ECB_STDC_VERSION >= 201112L)
88 105
89#if ECB_CPP 106#if ECB_CPP
90 #define ECB_EXTERN_C extern "C" 107 #define ECB_EXTERN_C extern "C"
91 #define ECB_EXTERN_C_BEG ECB_EXTERN_C { 108 #define ECB_EXTERN_C_BEG ECB_EXTERN_C {
92 #define ECB_EXTERN_C_END } 109 #define ECB_EXTERN_C_END }
… …
125 || defined __ARM_ARCH_6K__ || defined __ARM_ARCH_6ZK__ 142 || defined __ARM_ARCH_6K__ || defined __ARM_ARCH_6ZK__
126 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("mcr p15,0,%0,c7,c10,5" : : "r" (0) : "memory") 143 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("mcr p15,0,%0,c7,c10,5" : : "r" (0) : "memory")
127 #elif defined __ARM_ARCH_7__ || defined __ARM_ARCH_7A__ \ 144 #elif defined __ARM_ARCH_7__ || defined __ARM_ARCH_7A__ \
128 || defined __ARM_ARCH_7M__ || defined __ARM_ARCH_7R__ 145 || defined __ARM_ARCH_7M__ || defined __ARM_ARCH_7R__
129 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("dmb" : : : "memory") 146 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("dmb" : : : "memory")
147 #elif __aarch64__
148 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("dmb ish" : : : "memory")
130 #elif __sparc || __sparc__ 149 #elif (__sparc || __sparc__) && !__sparcv8
131 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("membar #LoadStore | #LoadLoad | #StoreStore | #StoreLoad" : : : "memory") 150 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("membar #LoadStore | #LoadLoad | #StoreStore | #StoreLoad" : : : "memory")
132 #define ECB_MEMORY_FENCE_ACQUIRE __asm__ __volatile__ ("membar #LoadStore | #LoadLoad" : : : "memory") 151 #define ECB_MEMORY_FENCE_ACQUIRE __asm__ __volatile__ ("membar #LoadStore | #LoadLoad" : : : "memory")
133 #define ECB_MEMORY_FENCE_RELEASE __asm__ __volatile__ ("membar #LoadStore | #StoreStore") 152 #define ECB_MEMORY_FENCE_RELEASE __asm__ __volatile__ ("membar #LoadStore | #StoreStore")
134 #elif defined __s390__ || defined __s390x__ 153 #elif defined __s390__ || defined __s390x__
135 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("bcr 15,0" : : : "memory") 154 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("bcr 15,0" : : : "memory")
136 #elif defined __mips__ 155 #elif defined __mips__
156 /* GNU/Linux emulates sync on mips1 architectures, so we force its use */
157 /* anybody else who still uses mips1 is supposed to send in their version, with detection code. */
137 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("sync" : : : "memory") 158 #define ECB_MEMORY_FENCE __asm__ __volatile__ (".set mips2; sync; .set mips0" : : : "memory")
138 #elif defined __alpha__ 159 #elif defined __alpha__
139 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("mb" : : : "memory") 160 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("mb" : : : "memory")
140 #elif defined __hppa__ 161 #elif defined __hppa__
141 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("" : : : "memory") 162 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("" : : : "memory")
142 #define ECB_MEMORY_FENCE_RELEASE __asm__ __volatile__ ("") 163 #define ECB_MEMORY_FENCE_RELEASE __asm__ __volatile__ ("")
143 #elif defined __ia64__ 164 #elif defined __ia64__
144 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("mf" : : : "memory") 165 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("mf" : : : "memory")
166 #elif defined __m68k__
167 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("" : : : "memory")
168 #elif defined __m88k__
169 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("tb1 0,%%r0,128" : : : "memory")
170 #elif defined __sh__
171 #define ECB_MEMORY_FENCE __asm__ __volatile__ ("" : : : "memory")
145 #endif 172 #endif
146 #endif 173 #endif
147#endif 174#endif
148 175
149#ifndef ECB_MEMORY_FENCE 176#ifndef ECB_MEMORY_FENCE
150 #if ECB_GCC_VERSION(4,7) 177 #if ECB_GCC_VERSION(4,7)
151 /* see comment below (stdatomic.h) about the C11 memory model. */ 178 /* see comment below (stdatomic.h) about the C11 memory model. */
152 #define ECB_MEMORY_FENCE __atomic_thread_fence (__ATOMIC_SEQ_CST) 179 #define ECB_MEMORY_FENCE __atomic_thread_fence (__ATOMIC_SEQ_CST)
180 #define ECB_MEMORY_FENCE_ACQUIRE __atomic_thread_fence (__ATOMIC_ACQUIRE)
181 #define ECB_MEMORY_FENCE_RELEASE __atomic_thread_fence (__ATOMIC_RELEASE)
182
183 /* The __has_feature syntax from clang is so misdesigned that we cannot use it
184 * without risking compile time errors with other compilers. We *could*
185 * define our own ecb_clang_has_feature, but I just can't be bothered to work
186 * around this shit time and again.
153 /*#elif defined __clang && __has_feature (cxx_atomic)*/ 187 * #elif defined __clang && __has_feature (cxx_atomic)
154 /* see comment below (stdatomic.h) about the C11 memory model. */ 188 * // see comment below (stdatomic.h) about the C11 memory model.
155 /*#define ECB_MEMORY_FENCE __c11_atomic_thread_fence (__ATOMIC_SEQ_CST)*/ 189 * #define ECB_MEMORY_FENCE __c11_atomic_thread_fence (__ATOMIC_SEQ_CST)
190 * #define ECB_MEMORY_FENCE_ACQUIRE __c11_atomic_thread_fence (__ATOMIC_ACQUIRE)
191 * #define ECB_MEMORY_FENCE_RELEASE __c11_atomic_thread_fence (__ATOMIC_RELEASE)
192 */
193
156 #elif ECB_GCC_VERSION(4,4) || defined __INTEL_COMPILER || defined __clang__ 194 #elif ECB_GCC_VERSION(4,4) || defined __INTEL_COMPILER || defined __clang__
157 #define ECB_MEMORY_FENCE __sync_synchronize () 195 #define ECB_MEMORY_FENCE __sync_synchronize ()
196 #elif _MSC_VER >= 1500 /* VC++ 2008 */
197 /* apparently, microsoft broke all the memory barrier stuff in Visual Studio 2008... */
198 #pragma intrinsic(_ReadBarrier,_WriteBarrier,_ReadWriteBarrier)
199 #define ECB_MEMORY_FENCE _ReadWriteBarrier (); MemoryBarrier()
200 #define ECB_MEMORY_FENCE_ACQUIRE _ReadWriteBarrier (); MemoryBarrier() /* according to msdn, _ReadBarrier is not a load fence */
201 #define ECB_MEMORY_FENCE_RELEASE _WriteBarrier (); MemoryBarrier()
158 #elif _MSC_VER >= 1400 /* VC++ 2005 */ 202 #elif _MSC_VER >= 1400 /* VC++ 2005 */
159 #pragma intrinsic(_ReadBarrier,_WriteBarrier,_ReadWriteBarrier) 203 #pragma intrinsic(_ReadBarrier,_WriteBarrier,_ReadWriteBarrier)
160 #define ECB_MEMORY_FENCE _ReadWriteBarrier () 204 #define ECB_MEMORY_FENCE _ReadWriteBarrier ()
161 #define ECB_MEMORY_FENCE_ACQUIRE _ReadWriteBarrier () /* according to msdn, _ReadBarrier is not a load fence */ 205 #define ECB_MEMORY_FENCE_ACQUIRE _ReadWriteBarrier () /* according to msdn, _ReadBarrier is not a load fence */
162 #define ECB_MEMORY_FENCE_RELEASE _WriteBarrier () 206 #define ECB_MEMORY_FENCE_RELEASE _WriteBarrier ()
… …
182 /* any fence other than seq_cst, which isn't very efficient for us. */ 226 /* any fence other than seq_cst, which isn't very efficient for us. */
183 /* Why that is, we don't know - either the C11 memory model is quite useless */ 227 /* Why that is, we don't know - either the C11 memory model is quite useless */
184 /* for most usages, or gcc and clang have a bug */ 228 /* for most usages, or gcc and clang have a bug */
185 /* I *currently* lean towards the latter, and inefficiently implement */ 229 /* I *currently* lean towards the latter, and inefficiently implement */
186 /* all three of ecb's fences as a seq_cst fence */ 230 /* all three of ecb's fences as a seq_cst fence */
231 /* Update, gcc-4.8 generates mfence for all c++ fences, but nothing */
232 /* for all __atomic_thread_fence's except seq_cst */
187 #define ECB_MEMORY_FENCE atomic_thread_fence (memory_order_seq_cst) 233 #define ECB_MEMORY_FENCE atomic_thread_fence (memory_order_seq_cst)
188 #endif 234 #endif
189#endif 235#endif
190 236
191#ifndef ECB_MEMORY_FENCE 237#ifndef ECB_MEMORY_FENCE
… …
248 #define ecb_is_constant(expr) __builtin_constant_p (expr) 294 #define ecb_is_constant(expr) __builtin_constant_p (expr)
249 #define ecb_expect(expr,value) __builtin_expect ((expr),(value)) 295 #define ecb_expect(expr,value) __builtin_expect ((expr),(value))
250 #define ecb_prefetch(addr,rw,locality) __builtin_prefetch (addr, rw, locality) 296 #define ecb_prefetch(addr,rw,locality) __builtin_prefetch (addr, rw, locality)
251#else 297#else
252 #define ecb_attribute(attrlist) 298 #define ecb_attribute(attrlist)
299
300 /* possible C11 impl for integral types
301 typedef struct ecb_is_constant_struct ecb_is_constant_struct;
302 #define ecb_is_constant(expr) _Generic ((1 ? (struct ecb_is_constant_struct *)0 : (void *)((expr) - (expr)), ecb_is_constant_struct *: 0, default: 1)) */
303
253 #define ecb_is_constant(expr) 0 304 #define ecb_is_constant(expr) 0
254 #define ecb_expect(expr,value) (expr) 305 #define ecb_expect(expr,value) (expr)
255 #define ecb_prefetch(addr,rw,locality) 306 #define ecb_prefetch(addr,rw,locality)
256#endif 307#endif
257 308
… …
475ecb_inline unsigned char ecb_byteorder_helper (void) ecb_const; 526ecb_inline unsigned char ecb_byteorder_helper (void) ecb_const;
476ecb_inline unsigned char 527ecb_inline unsigned char
477ecb_byteorder_helper (void) 528ecb_byteorder_helper (void)
478{ 529{
479 /* the union code still generates code under pressure in gcc, */ 530 /* the union code still generates code under pressure in gcc, */
480 /* but less than using pointers, and always seem to */ 531 /* but less than using pointers, and always seems to */
481 /* successfully return a constant. */ 532 /* successfully return a constant. */
482 /* the reason why we have this horrible preprocessor mess */ 533 /* the reason why we have this horrible preprocessor mess */
483 /* is to avoid it in all cases, at least on common architectures */ 534 /* is to avoid it in all cases, at least on common architectures */
484 /* and yes, gcc defines __BYTE_ORDER__, g++ does not */ 535 /* or when using a recent enough gcc version (>= 4.6) */
485#if __i386 || __i386__ || _M_X86 || __amd64 || __amd64__ || _M_X64 536#if __i386 || __i386__ || _M_X86 || __amd64 || __amd64__ || _M_X64
486 return 0x44; 537 return 0x44;
487#elif __BYTE_ORDER__ && __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__ 538#elif __BYTE_ORDER__ && __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
488 return 0x44; 539 return 0x44;
489#elif __BYTE_ORDER__ && __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__ 540#elif __BYTE_ORDER__ && __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
490 retrurn 0x11; 541 return 0x11;
491#else 542#else
492 union 543 union
493 { 544 {
494 uint32_t i; 545 uint32_t i;
495 uint8_t c; 546 uint8_t c;
… …
534 } 585 }
535#else 586#else
536 #define ecb_array_length(name) (sizeof (name) / sizeof (name [0])) 587 #define ecb_array_length(name) (sizeof (name) / sizeof (name [0]))
537#endif 588#endif
538 589
539#if __STDC_IEC_559__ 590/*******************************************************************************/
540 // we assume this is defined for most C and many C++ compilers 591/* floating point stuff, can be disabled by defining ECB_NO_LIBM */
541 ecb_inline ecb_bool ecb_float_ieee (void) ecb_const; 592
542 ecb_inline ecb_bool ecb_float_ieee (void) { return 1; } 593/* basically, everything uses "ieee pure-endian" floating point numbers */
543 ecb_inline ecb_bool ecb_double_ieee (void) ecb_const; 594/* the only noteworthy exception is ancient armle, which uses order 43218765 */
544 ecb_inline ecb_bool ecb_double_ieee (void) { return 1; } 595#if 0 \
545#elif ECB_CPP 596 || __i386 || __i386__ \
546 #include <limits> 597 || __amd64 || __amd64__ || __x86_64 || __x86_64__ \
547 ecb_inline ecb_bool ecb_float_ieee (void) ecb_const; 598 || __powerpc__ || __ppc__ || __powerpc64__ || __ppc64__ \
548 ecb_inline ecb_bool ecb_float_ieee (void) { return std::numeric_limits<float >::is_iec559; } 599 || defined __arm__ && defined __ARM_EABI__ \
549 ecb_inline ecb_bool ecb_double_ieee (void) ecb_const; 600 || defined __s390__ || defined __s390x__ \
550 ecb_inline ecb_bool ecb_double_ieee (void) { return std::numeric_limits<double>::is_iec559; } 601 || defined __mips__ \
602 || defined __alpha__ \
603 || defined __hppa__ \
604 || defined __ia64__ \
605 || defined __m68k__ \
606 || defined __m88k__ \
607 || defined __sh__ \
608 || defined _M_IX86 || defined _M_AMD64 || defined _M_IA64 \
609 || (defined __arm__ && (defined __ARM_EABI__ || defined __EABI__ || defined __VFP_FP__ || defined _WIN32_WCE || defined __ANDROID__))
610 #define ECB_STDFP 1
611 #include <string.h> /* for memcpy */
612#else
613 #define ECB_STDFP 0
614#endif
615
616#ifndef ECB_NO_LIBM
617
618 #include <math.h> /* for frexp*, ldexp*, INFINITY, NAN */
619
620 /* only the oldest of old doesn't have this one. solaris. */
621 #ifdef INFINITY
622 #define ECB_INFINITY INFINITY
551#else 623 #else
552 ecb_inline ecb_bool ecb_float_ieee (void) ecb_const; 624 #define ECB_INFINITY HUGE_VAL
553 ecb_inline ecb_bool ecb_float_ieee (void) { return 0; }
554 ecb_inline ecb_bool ecb_double_ieee (void) ecb_const;
555 ecb_inline ecb_bool ecb_double_ieee (void) { return 0; }
556#endif 625 #endif
557 626
627 #ifdef NAN
628 #define ECB_NAN NAN
629 #else
630 #define ECB_NAN ECB_INFINITY
631 #endif
632
633 /* converts an ieee half/binary16 to a float */
634 ecb_function_ float ecb_binary16_to_float (uint16_t x) ecb_const;
635 ecb_function_ float
636 ecb_binary16_to_float (uint16_t x)
637 {
638 int e = (x >> 10) & 0x1f;
639 int m = x & 0x3ff;
640 float r;
641
642 if (!e ) r = ldexpf (m , -24);
643 else if (e != 31) r = ldexpf (m + 0x400, e - 25);
644 else if (m ) r = ECB_NAN;
645 else r = ECB_INFINITY;
646
647 return x & 0x8000 ? -r : r;
648 }
649
558// convert a float to ieee single/binary32 650 /* convert a float to ieee single/binary32 */
559ecb_function_ uint32_t ecb_float_to_binary32 (float x) ecb_const; 651 ecb_function_ uint32_t ecb_float_to_binary32 (float x) ecb_const;
560ecb_function_ uint32_t 652 ecb_function_ uint32_t
561ecb_float_to_binary32 (float x) 653 ecb_float_to_binary32 (float x)
562{ 654 {
655 uint32_t r;
656
657 #if ECB_STDFP
658 memcpy (&r, &x, 4);
659 #else
563 /* slow emulation, works for anything but nan's and -0 */ 660 /* slow emulation, works for anything but -0 */
564 ECB_EXTERN_C float frexpf (float v, int *e);
565 uint32_t r, m; 661 uint32_t m;
566 int e; 662 int e;
567 663
568 if (x == 0e0f ) return 0; 664 if (x == 0e0f ) return 0x00000000U;
569 if (x > +3.40282346638528860e+38f) return 0x7f800000U; 665 if (x > +3.40282346638528860e+38f) return 0x7f800000U;
570 if (x < -3.40282346638528860e+38f) return 0xff800000U; 666 if (x < -3.40282346638528860e+38f) return 0xff800000U;
667 if (x != x ) return 0x7fbfffffU;
571 668
572 m = frexpf (x, &e) * 0x1000000U; 669 m = frexpf (x, &e) * 0x1000000U;
573 670
574 r = m & 0x80000000U; 671 r = m & 0x80000000U;
575 672
576 if (r) 673 if (r)
577 m = -m; 674 m = -m;
578 675
579 if (e < -125) 676 if (e <= -126)
580 { 677 {
581 m &= 0xffffffU; 678 m &= 0xffffffU;
582 m >>= (-125 - e); 679 m >>= (-125 - e);
583 e = -126; 680 e = -126;
584 } 681 }
585 682
586 r |= (e + 126) << 23; 683 r |= (e + 126) << 23;
587 r |= m & 0x7fffffU; 684 r |= m & 0x7fffffU;
685 #endif
588 686
589 return r; 687 return r;
590} 688 }
591 689
592// converts a ieee single/binary32 to a float 690 /* converts an ieee single/binary32 to a float */
593ecb_function_ float ecb_binary32_to_float (uint32_t x) ecb_const; 691 ecb_function_ float ecb_binary32_to_float (uint32_t x) ecb_const;
594ecb_function_ float 692 ecb_function_ float
595ecb_binary32_to_float (uint32_t x) 693 ecb_binary32_to_float (uint32_t x)
596{ 694 {
695 float r;
696
697 #if ECB_STDFP
698 memcpy (&r, &x, 4);
699 #else
597 /* emulation, only works for normals and subnormals and +0 */ 700 /* emulation, only works for normals and subnormals and +0 */
598 ECB_EXTERN_C float ldexpf (float x, int e);
599
600 int neg = x >> 31; 701 int neg = x >> 31;
601 int e = (x >> 23) & 0xffU; 702 int e = (x >> 23) & 0xffU;
602 float r;
603 703
604 x &= 0x7fffffU; 704 x &= 0x7fffffU;
605 705
606 if (e) 706 if (e)
607 x |= 0x800000U; 707 x |= 0x800000U;
708 else
709 e = 1;
608 710
609 /* we distrust ldexpf a bit and do the 2**-24 scaling by an extra multiply */ 711 /* we distrust ldexpf a bit and do the 2**-24 scaling by an extra multiply */
610 r = ldexpf (x * (1.f / 0x1000000U), e - 126); 712 r = ldexpf (x * (0.5f / 0x800000U), e - 126);
611 713
612 return neg ? -r : r; 714 r = neg ? -r : r;
613} 715 #endif
614 716
717 return r;
718 }
719
720 /* convert a double to ieee double/binary64 */
615ecb_function_ uint64_t ecb_double_to_binary64 (double x) ecb_const; 721 ecb_function_ uint64_t ecb_double_to_binary64 (double x) ecb_const;
616ecb_function_ uint64_t 722 ecb_function_ uint64_t
617ecb_double_to_binary64 (double x) 723 ecb_double_to_binary64 (double x)
618{ 724 {
619} 725 uint64_t r;
620 726
727 #if ECB_STDFP
728 memcpy (&r, &x, 8);
729 #else
730 /* slow emulation, works for anything but -0 */
731 uint64_t m;
732 int e;
733
734 if (x == 0e0 ) return 0x0000000000000000U;
735 if (x > +1.79769313486231470e+308) return 0x7ff0000000000000U;
736 if (x < -1.79769313486231470e+308) return 0xfff0000000000000U;
737 if (x != x ) return 0X7ff7ffffffffffffU;
738
739 m = frexp (x, &e) * 0x20000000000000U;
740
741 r = m & 0x8000000000000000;;
742
743 if (r)
744 m = -m;
745
746 if (e <= -1022)
747 {
748 m &= 0x1fffffffffffffU;
749 m >>= (-1021 - e);
750 e = -1022;
751 }
752
753 r |= ((uint64_t)(e + 1022)) << 52;
754 r |= m & 0xfffffffffffffU;
621#endif 755 #endif
622 756
757 return r;
758 }
759
760 /* converts an ieee double/binary64 to a double */
761 ecb_function_ double ecb_binary64_to_double (uint64_t x) ecb_const;
762 ecb_function_ double
763 ecb_binary64_to_double (uint64_t x)
764 {
765 double r;
766
767 #if ECB_STDFP
768 memcpy (&r, &x, 8);
769 #else
770 /* emulation, only works for normals and subnormals and +0 */
771 int neg = x >> 63;
772 int e = (x >> 52) & 0x7ffU;
773
774 x &= 0xfffffffffffffU;
775
776 if (e)
777 x |= 0x10000000000000U;
778 else
779 e = 1;
780
781 /* we distrust ldexp a bit and do the 2**-53 scaling by an extra multiply */
782 r = ldexp (x * (0.5 / 0x10000000000000U), e - 1022);
783
784 r = neg ? -r : r;
785 #endif
786
787 return r;
788 }
789
790#endif
791
792#endif
793

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