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 * Eclipse Public License, Version 1.0 *
7 * by AT&T Intellectual Property *
8 * *
9 * A copy of the License is available at *
10 * http://www.eclipse.org/org/documents/epl-v10.html *
11 * (with md5 checksum b35adb5213ca9657e911e9befb180842) *
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
_sfputd(Sfio_t * f,Sfdouble_t v)30 int _sfputd(Sfio_t* f, Sfdouble_t v)
31 #else
32 int _sfputd(f,v)
33 Sfio_t* f;
34 Sfdouble_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