summaryrefslogtreecommitdiff
path: root/lib/libc/gdtoa/smisc.c
blob: d063a38db270d4ebb9a663059ec523ba310a08b3 (plain)
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
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
/****************************************************************

The author of this software is David M. Gay.

Copyright (C) 1998, 1999 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 at acm dot org,
 * with " at " changed at "@" and " dot " changed to ".").	*/

#include "gdtoaimp.h"

 Bigint *
s2b
#ifdef KR_headers
	(s, nd0, nd, y9, dplen) CONST char *s; int dplen, nd0, nd; ULong y9;
#else
	(CONST char *s, int nd0, int nd, ULong y9, int dplen)
#endif
{
	Bigint *b;
	int i, k;
	Long x, y;

	x = (nd + 8) / 9;
	for(k = 0, y = 1; x > y; y <<= 1, k++) ;
#ifdef Pack_32
	b = Balloc(k);
	if (b == NULL)
		return (NULL);
	b->x[0] = y9;
	b->wds = 1;
#else
	b = Balloc(k+1);
	if (b == NULL)
		return (NULL);
	b->x[0] = y9 & 0xffff;
	b->wds = (b->x[1] = y9 >> 16) ? 2 : 1;
#endif

	i = 9;
	if (9 < nd0) {
		s += 9;
		do {
			b = multadd(b, 10, *s++ - '0');
			if (b == NULL)
				return (NULL);
			} while(++i < nd0);
		s += dplen;
		}
	else
		s += dplen + 9;
	for(; i < nd; i++) {
		b = multadd(b, 10, *s++ - '0');
		if (b == NULL)
			return (NULL);
		}
	return b;
	}

 double
ratio
#ifdef KR_headers
	(a, b) Bigint *a, *b;
#else
	(Bigint *a, Bigint *b)
#endif
{
	U da, db;
	int k, ka, kb;

	dval(&da) = b2d(a, &ka);
	dval(&db) = b2d(b, &kb);
	k = ka - kb + ULbits*(a->wds - b->wds);
#ifdef IBM
	if (k > 0) {
		word0(&da) += (k >> 2)*Exp_msk1;
		if (k &= 3)
			dval(&da) *= 1 << k;
		}
	else {
		k = -k;
		word0(&db) += (k >> 2)*Exp_msk1;
		if (k &= 3)
			dval(&db) *= 1 << k;
		}
#else
	if (k > 0)
		word0(&da) += k*Exp_msk1;
	else {
		k = -k;
		word0(&db) += k*Exp_msk1;
		}
#endif
	return dval(&da) / dval(&db);
	}

#ifdef INFNAN_CHECK

 int
match
#ifdef KR_headers
	(sp, t) char **sp, *t;
#else
	(CONST char **sp, char *t)
#endif
{
	int c, d;
	CONST char *s = *sp;

	while( (d = *t++) !=0) {
		if ((c = *++s) >= 'A' && c <= 'Z')
			c += 'a' - 'A';
		if (c != d)
			return 0;
		}
	*sp = s + 1;
	return 1;
	}
#endif /* INFNAN_CHECK */

 void
#ifdef KR_headers
copybits(c, n, b) ULong *c; int n; Bigint *b;
#else
copybits(ULong *c, int n, Bigint *b)
#endif
{
	ULong *ce, *x, *xe;
#ifdef Pack_16
	int nw, nw1;
#endif

	ce = c + ((n-1) >> kshift) + 1;
	x = b->x;
#ifdef Pack_32
	xe = x + b->wds;
	while(x < xe)
		*c++ = *x++;
#else
	nw = b->wds;
	nw1 = nw & 1;
	for(xe = x + (nw - nw1); x < xe; x += 2)
		Storeinc(c, x[1], x[0]);
	if (nw1)
		*c++ = *x;
#endif
	while(c < ce)
		*c++ = 0;
	}

 ULong
#ifdef KR_headers
any_on(b, k) Bigint *b; int k;
#else
any_on(Bigint *b, int k)
#endif
{
	int n, nwds;
	ULong *x, *x0, x1, x2;

	x = b->x;
	nwds = b->wds;
	n = k >> kshift;
	if (n > nwds)
		n = nwds;
	else if (n < nwds && (k &= kmask)) {
		x1 = x2 = x[n];
		x1 >>= k;
		x1 <<= k;
		if (x1 != x2)
			return 1;
		}
	x0 = x;
	x += n;
	while(x > x0)
		if (*--x)
			return 1;
	return 0;
	}