1/***********************************************************************
2*                                                                      *
3*               This software is part of the ast package               *
4*          Copyright (c) 1985-2011 AT&T Intellectual Property          *
5*                      and is licensed under the                       *
6*                  Common Public License, Version 1.0                  *
7*                    by AT&T Intellectual Property                     *
8*                                                                      *
9*                A copy of the License is available at                 *
10*            http://www.opensource.org/licenses/cpl1.0.txt             *
11*         (with md5 checksum 059e8cd6165cb4c31e351f2b69388fd9)         *
12*                                                                      *
13*              Information and Software Systems Research               *
14*                            AT&T Research                             *
15*                           Florham Park NJ                            *
16*                                                                      *
17*                 Glenn Fowler <gsf@research.att.com>                  *
18*                  David Korn <dgk@research.att.com>                   *
19*                   Phong Vo <kpv@research.att.com>                    *
20*                                                                      *
21***********************************************************************/
22#include	"sfhdr.h"
23
24/*	Write out a floating point value in a portable format
25**
26**	Written by Kiem-Phong Vo.
27*/
28
29#if __STD_C
30int _sfputd(Sfio_t* f, Sfdouble_t v)
31#else
32int _sfputd(f,v)
33Sfio_t*		f;
34Sfdouble_t	v;
35#endif
36{
37#define N_ARRAY		(16*sizeof(Sfdouble_t))
38	reg ssize_t	n, w;
39	reg uchar	*s, *ends;
40	int		exp;
41	uchar		c[N_ARRAY];
42	Sfdouble_t	x;
43	SFMTXDECL(f);
44
45	SFMTXENTER(f,-1);
46
47	if(f->mode != SF_WRITE && _sfmode(f,SF_WRITE,0) < 0)
48		SFMTXRETURN(f, -1);
49	SFLOCK(f,0);
50
51	/* get the sign of v */
52	if(v < 0.)
53	{	v = -v;
54		n = 1;
55	}
56	else	n = 0;
57
58	/* make the magnitude of v < 1 */
59	if(v != 0.)
60		v = frexpl(v,&exp);
61	else	exp = 0;
62
63	/* code the sign of v and exp */
64	if((w = exp) < 0)
65	{	n |= 02;
66		w = -w;
67	}
68
69	/* write out the signs and the exp */
70	SFOPEN(f,0);
71	if(sfputc(f,n) < 0 || (w = sfputu(f,w)) < 0)
72		SFMTXRETURN(f, -1);
73	SFLOCK(f,0);
74	w += 1;
75
76	s = (ends = &c[0])+sizeof(c);
77	while(s > ends)
78	{	/* get 2^SF_PRECIS precision at a time */
79		n = (int)(x = ldexpl(v,SF_PRECIS));
80		*--s = n|SF_MORE;
81		v = x-n;
82		if(v <= 0.)
83			break;
84	}
85
86	/* last byte is not SF_MORE */
87	ends = &c[0] + sizeof(c) -1;
88	*ends &= ~SF_MORE;
89
90	/* write out coded bytes */
91	n = ends - s + 1;
92	w = SFWRITE(f,(Void_t*)s,n) == n ? w+n : -1;
93
94	SFOPEN(f,0);
95	SFMTXRETURN(f,w);
96}
97