1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
|
/****************************************************************
The author of this software is David M. Gay.
Copyright (C) 1998 by Lucent Technologies
All Rights Reserved
Permission to use, copy, modify, and distribute this software and
its documentation for any purpose and without fee is hereby
granted, provided that the above copyright notice appear in all
copies and that both that the copyright notice and this
permission notice and warranty disclaimer appear in supporting
documentation, and that the name of Lucent or any of its entities
not be used in advertising or publicity pertaining to
distribution of the software without specific, written prior
permission.
LUCENT DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS.
IN NO EVENT SHALL LUCENT OR ANY OF ITS ENTITIES BE LIABLE FOR ANY
SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER
IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF
THIS SOFTWARE.
****************************************************************/
/* Please send bug reports to David M. Gay (dmg@acm.org). */
#include "gdtoaimp.h"
#include <string.h>
char *
#ifdef KR_headers
g_ddfmt(buf, dd, ndig, bufsize) char *buf; double *dd; int ndig; unsigned bufsize;
#else
g_ddfmt(char *buf, double *dd, int ndig, unsigned bufsize)
#endif
{
FPI fpi;
char *b, *s, *se;
ULong *L, bits0[4], *bits, *zx;
int bx, by, decpt, ex, ey, i, j, mode;
Bigint *x, *y, *z;
double ddx[2];
if (bufsize < 10 || bufsize < ndig + 8)
return 0;
L = (ULong*)dd;
if ((L[_0] & 0x7ff00000L) == 0x7ff00000L) {
/* Infinity or NaN */
if (L[_0] & 0xfffff || L[_1]) {
nanret:
return strcp(buf, "NaN");
}
if ((L[2+_0] & 0x7ff00000) == 0x7ff00000) {
if (L[2+_0] & 0xfffff || L[2+_1])
goto nanret;
if ((L[_0] ^ L[2+_0]) & 0x80000000L)
goto nanret; /* Infinity - Infinity */
}
infret:
b = buf;
if (L[_0] & 0x80000000L)
*b++ = '-';
return strcp(b, "Infinity");
}
if ((L[2+_0] & 0x7ff00000) == 0x7ff00000) {
L += 2;
if (L[_0] & 0xfffff || L[_1])
goto nanret;
goto infret;
}
if (dd[0] + dd[1] == 0.) {
b = buf;
#ifndef IGNORE_ZERO_SIGN
if (L[_0] & L[2+_0] & 0x80000000L)
*b++ = '-';
#endif
*b++ = '0';
*b = 0;
return b;
}
if ((L[_0] & 0x7ff00000L) < (L[2+_0] & 0x7ff00000L)) {
ddx[1] = dd[0];
ddx[0] = dd[1];
dd = ddx;
L = (ULong*)dd;
}
z = d2b(dd[0], &ex, &bx);
if (dd[1] == 0.)
goto no_y;
x = z;
y = d2b(dd[1], &ey, &by);
if ( (i = ex - ey) !=0) {
if (i > 0) {
x = lshift(x, i);
ex = ey;
}
else
y = lshift(y, -i);
}
if ((L[_0] ^ L[2+_0]) & 0x80000000L) {
z = diff(x, y);
if (L[_0] & 0x80000000L)
z->sign = 1 - z->sign;
}
else {
z = sum(x, y);
if (L[_0] & 0x80000000L)
z->sign = 1;
}
Bfree(x);
Bfree(y);
no_y:
bits = zx = z->x;
for(i = 0; !*zx; zx++)
i += 32;
i += lo0bits(zx);
if (i) {
rshift(z, i);
ex += i;
}
fpi.nbits = z->wds * 32 - hi0bits(z->x[j = z->wds-1]);
if (fpi.nbits < 106) {
fpi.nbits = 106;
if (j < 3) {
for(i = 0; i <= j; i++)
bits0[i] = bits[i];
while(i < 4)
bits0[i++] = 0;
bits = bits0;
}
}
mode = 2;
if (ndig <= 0) {
if (bufsize < (int)(fpi.nbits * .301029995664) + 10) {
Bfree(z);
return 0;
}
mode = 0;
}
fpi.emin = 1-1023-53+1;
fpi.emax = 2046-1023-106+1;
fpi.rounding = FPI_Round_near;
fpi.sudden_underflow = 0;
i = STRTOG_Normal;
s = gdtoa(&fpi, ex, bits, &i, mode, ndig, &decpt, &se);
b = g__fmt(buf, s, se, decpt, z->sign);
Bfree(z);
return b;
}
|
