g_xfmt.c revision 112158 
1/****************************************************************
2
3The author of this software is David M. Gay.
4
5Copyright (C) 1998 by Lucent Technologies
6All Rights Reserved
7
8Permission to use, copy, modify, and distribute this software and
9its documentation for any purpose and without fee is hereby
10granted, provided that the above copyright notice appear in all
11copies and that both that the copyright notice and this
12permission notice and warranty disclaimer appear in supporting
13documentation, and that the name of Lucent or any of its entities
14not be used in advertising or publicity pertaining to
15distribution of the software without specific, written prior
16permission.
17
18LUCENT DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
19INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS.
20IN NO EVENT SHALL LUCENT OR ANY OF ITS ENTITIES BE LIABLE FOR ANY
21SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
22WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER
23IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
24ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF
25THIS SOFTWARE.
26
27****************************************************************/
28
29/* Please send bug reports to
30	David M. Gay
31	Bell Laboratories, Room 2C-463
32	600 Mountain Avenue
33	Murray Hill, NJ 07974-0636
34	U.S.A.
35	dmg@bell-labs.com
36 */
37
38#include "gdtoaimp.h"
39
40#undef _0
41#undef _1
42
43/* one or the other of IEEE_MC68k or IEEE_8087 should be #defined */
44
45#ifdef IEEE_MC68k
46#define _0 0
47#define _1 1
48#define _2 2
49#define _3 3
50#define _4 4
51#endif
52#ifdef IEEE_8087
53#define _0 4
54#define _1 3
55#define _2 2
56#define _3 1
57#define _4 0
58#endif
59
60 char*
61#ifdef KR_headers
62g_xfmt(buf, V, ndig, bufsize) char *buf; char *V; int ndig; unsigned bufsize;
63#else
64g_xfmt(char *buf, void *V, int ndig, unsigned bufsize)
65#endif
66{
67	static FPI fpi = { 64, 1-16383-64+1, 32766 - 16383 - 64 + 1, 1, 0 };
68	char *b, *s, *se;
69	ULong bits[2], sign;
70	UShort *L;
71	int decpt, ex, i, mode;
72
73	if (ndig < 0)
74		ndig = 0;
75	if (bufsize < ndig + 10)
76		return 0;
77
78	L = (UShort *)V;
79	sign = L[_0] & 0x8000;
80	bits[1] = (L[_1] << 16) | L[_2];
81	bits[0] = (L[_3] << 16) | L[_4];
82	if ( (ex = L[_0] & 0x7fff) !=0) {
83		if (ex == 0x7fff) {
84			/* Infinity or NaN */
85			if (bits[0] | bits[1])
86				b = strcp(buf, "NaN");
87			else {
88				b = buf;
89				if (sign)
90					*b++ = '-';
91				b = strcp(b, "Infinity");
92				}
93			return b;
94			}
95		i = STRTOG_Normal;
96		}
97	else if (bits[0] | bits[1]) {
98		i = STRTOG_Denormal;
99		}
100	else {
101		b = buf;
102#ifndef IGNORE_ZERO_SIGN
103		if (sign)
104			*b++ = '-';
105#endif
106		*b++ = '0';
107		*b = 0;
108		return b;
109		}
110	ex -= 0x3fff + 63;
111	mode = 2;
112	if (ndig <= 0) {
113		if (bufsize < 32)
114			return 0;
115		mode = 0;
116		}
117	s = gdtoa(&fpi, ex, bits, &i, mode, ndig, &decpt, &se);
118	return g__fmt(buf, s, se, decpt, sign);
119	}
120