1/* $NetBSD: g_xfmt.c,v 1.5 2019/08/01 02:27:43 riastradh Exp $ */
2
3/****************************************************************
4
5The author of this software is David M. Gay.
6
7Copyright (C) 1998 by Lucent Technologies
8All Rights Reserved
9
10Permission to use, copy, modify, and distribute this software and
11its documentation for any purpose and without fee is hereby
12granted, provided that the above copyright notice appear in all
13copies and that both that the copyright notice and this
14permission notice and warranty disclaimer appear in supporting
15documentation, and that the name of Lucent or any of its entities
16not be used in advertising or publicity pertaining to
17distribution of the software without specific, written prior
18permission.
19
20LUCENT DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
21INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS.
22IN NO EVENT SHALL LUCENT OR ANY OF ITS ENTITIES BE LIABLE FOR ANY
23SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
24WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER
25IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
26ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF
27THIS SOFTWARE.
28
29****************************************************************/
30
31/* Please send bug reports to David M. Gay (dmg at acm dot org,
32 * with " at " changed at "@" and " dot " changed to ".").	*/
33
34#include "gdtoaimp.h"
35
36#undef _0
37#undef _1
38
39/* one or the other of IEEE_BIG_ENDIAN or IEEE_LITTLE_ENDIAN should be #defined */
40
41#ifdef IEEE_BIG_ENDIAN
42#define _0 0
43#define _1 1
44#define _2 2
45#define _3 3
46#define _4 4
47#endif
48#ifdef IEEE_LITTLE_ENDIAN
49#define _0 4
50#define _1 3
51#define _2 2
52#define _3 1
53#define _4 0
54#endif
55
56 char*
57#ifdef KR_headers
58g_xfmt(buf, V, ndig, bufsize) char *buf; char *V; int ndig; size_t bufsize;
59#else
60g_xfmt(char *buf, void *V, int ndig, size_t bufsize)
61#endif
62{
63	static CONST FPI fpi0 = { 64, 1-16383-64+1, 32766 - 16383 - 64 + 1, 1, 0 };
64	char *b, *s, *se;
65	ULong bits[2], sign;
66	UShort *L;
67	int decpt, ex, i, mode;
68#ifdef Honor_FLT_ROUNDS
69#include "gdtoa_fltrnds.h"
70#else
71#define fpi &fpi0
72#endif
73
74	if (ndig < 0)
75		ndig = 0;
76	if (bufsize < ndig + 10)
77		return 0;
78
79	L = (UShort *)V;
80	sign = L[_0] & 0x8000;
81	bits[1] = (L[_1] << 16) | L[_2];
82	bits[0] = (L[_3] << 16) | L[_4];
83	if ( (ex = L[_0] & 0x7fff) !=0) {
84		if (ex == 0x7fff) {
85			/* Infinity or NaN */
86			if (bits[0] | bits[1])
87				b = strcp(buf, "NaN");
88			else {
89				b = buf;
90				if (sign)
91					*b++ = '-';
92				b = strcp(b, "Infinity");
93				}
94			return b;
95			}
96		i = STRTOG_Normal;
97		}
98	else if (bits[0] | bits[1]) {
99		i = STRTOG_Denormal;
100		ex = 1;
101		}
102	else {
103		b = buf;
104#ifndef IGNORE_ZERO_SIGN
105		if (sign)
106			*b++ = '-';
107#endif
108		*b++ = '0';
109		*b = 0;
110		return b;
111		}
112	ex -= 0x3fff + 63;
113	mode = 2;
114	if (ndig <= 0) {
115		if (bufsize < 32)
116			return 0;
117		mode = 0;
118		}
119	s = gdtoa(fpi, ex, bits, &i, mode, ndig, &decpt, &se);
120	if (s == NULL)
121		return NULL;
122	return g__fmt(buf, s, se, decpt, sign, bufsize);
123	}
124