strtordd.c revision 267654 
1/****************************************************************
2
3The author of this software is David M. Gay.
4
5Copyright (C) 1998, 2000 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 David M. Gay (dmg at acm dot org,
30 * with " at " changed at "@" and " dot " changed to ".").	*/
31
32#include "gdtoaimp.h"
33
34 void
35#ifdef KR_headers
36ULtodd(L, bits, exp, k) ULong *L; ULong *bits; Long exp; int k;
37#else
38ULtodd(ULong *L, ULong *bits, Long exp, int k)
39#endif
40{
41	int i, j;
42
43	switch(k & STRTOG_Retmask) {
44	  case STRTOG_NoNumber:
45	  case STRTOG_Zero:
46		L[0] = L[1] = L[2] = L[3] = 0;
47		break;
48
49	  case STRTOG_Normal:
50		L[_1] = (bits[1] >> 21 | bits[2] << 11) & (ULong)0xffffffffL;
51		L[_0] = (bits[2] >> 21) | (bits[3] << 11 & 0xfffff)
52			  | ((exp + 0x3ff + 105) << 20);
53		exp += 0x3ff + 52;
54		if (bits[1] &= 0x1fffff) {
55			i = hi0bits(bits[1]) - 11;
56			if (i >= exp) {
57				i = exp - 1;
58				exp = 0;
59				}
60			else
61				exp -= i;
62			if (i > 0) {
63				bits[1] = bits[1] << i | bits[0] >> (32-i);
64				bits[0] = bits[0] << i & (ULong)0xffffffffL;
65				}
66			}
67		else if (bits[0]) {
68			i = hi0bits(bits[0]) + 21;
69			if (i >= exp) {
70				i = exp - 1;
71				exp = 0;
72				}
73			else
74				exp -= i;
75			if (i < 32) {
76				bits[1] = bits[0] >> (32 - i);
77				bits[0] = bits[0] << i & (ULong)0xffffffffL;
78				}
79			else {
80				bits[1] = bits[0] << (i - 32);
81				bits[0] = 0;
82				}
83			}
84		else {
85			L[2] = L[3] = 0;
86			break;
87			}
88		L[2+_1] = bits[0];
89		L[2+_0] = (bits[1] & 0xfffff) | (exp << 20);
90		break;
91
92	  case STRTOG_Denormal:
93		if (bits[3])
94			goto nearly_normal;
95		if (bits[2])
96			goto partly_normal;
97		if (bits[1] & 0xffe00000)
98			goto hardly_normal;
99		/* completely denormal */
100		L[2] = L[3] = 0;
101		L[_1] = bits[0];
102		L[_0] = bits[1];
103		break;
104
105	  nearly_normal:
106		i = hi0bits(bits[3]) - 11;	/* i >= 12 */
107		j = 32 - i;
108		L[_0] = ((bits[3] << i | bits[2] >> j) & 0xfffff)
109			| ((65 - i) << 20);
110		L[_1] = (bits[2] << i | bits[1] >> j) & 0xffffffffL;
111		L[2+_0] = bits[1] & (((ULong)1L << j) - 1);
112		L[2+_1] = bits[0];
113		break;
114
115	  partly_normal:
116		i = hi0bits(bits[2]) - 11;
117		if (i < 0) {
118			j = -i;
119			i += 32;
120			L[_0] = (bits[2] >> j & 0xfffff) | ((33 + j) << 20);
121			L[_1] = (bits[2] << i | bits[1] >> j) & 0xffffffffL;
122			L[2+_0] = bits[1] & (((ULong)1L << j) - 1);
123			L[2+_1] = bits[0];
124			break;
125			}
126		if (i == 0) {
127			L[_0] = (bits[2] & 0xfffff) | (33 << 20);
128			L[_1] = bits[1];
129			L[2+_0] = 0;
130			L[2+_1] = bits[0];
131			break;
132			}
133		j = 32 - i;
134		L[_0] = (((bits[2] << i) | (bits[1] >> j)) & 0xfffff)
135				| ((j + 1) << 20);
136		L[_1] = (bits[1] << i | bits[0] >> j) & 0xffffffffL;
137		L[2+_0] = 0;
138		L[2+_1] = bits[0] & ((1L << j) - 1);
139		break;
140
141	  hardly_normal:
142		j = 11 - hi0bits(bits[1]);
143		i = 32 - j;
144		L[_0] = (bits[1] >> j & 0xfffff) | ((j + 1) << 20);
145		L[_1] = (bits[1] << i | bits[0] >> j) & 0xffffffffL;
146		L[2+_0] = 0;
147		L[2+_1] = bits[0] & (((ULong)1L << j) - 1);
148		break;
149
150	  case STRTOG_Infinite:
151		L[_0] = L[2+_0] = 0x7ff00000;
152		L[_1] = L[2+_1] = 0;
153		break;
154
155	  case STRTOG_NaN:
156		L[0] = L[2] = d_QNAN0;
157		L[1] = L[3] = d_QNAN1;
158		break;
159
160	  case STRTOG_NaNbits:
161		L[_1] = (bits[1] >> 21 | bits[2] << 11) & (ULong)0xffffffffL;
162		L[_0] = bits[2] >> 21 | bits[3] << 11
163			  | (ULong)0x7ff00000L;
164		L[2+_1] = bits[0];
165		L[2+_0] = bits[1] | (ULong)0x7ff00000L;
166	  }
167	if (k & STRTOG_Neg) {
168		L[_0] |= 0x80000000L;
169		L[2+_0] |= 0x80000000L;
170		}
171	}
172
173 int
174#ifdef KR_headers
175strtordd(s, sp, rounding, dd) CONST char *s; char **sp; int rounding; double *dd;
176#else
177strtordd(CONST char *s, char **sp, int rounding, double *dd)
178#endif
179{
180#ifdef Sudden_Underflow
181	static FPI fpi0 = { 106, 1-1023, 2046-1023-106+1, 1, 1 };
182#else
183	static FPI fpi0 = { 106, 1-1023-53+1, 2046-1023-106+1, 1, 0 };
184#endif
185	FPI *fpi, fpi1;
186	ULong bits[4];
187	Long exp;
188	int k;
189
190	fpi = &fpi0;
191	if (rounding != FPI_Round_near) {
192		fpi1 = fpi0;
193		fpi1.rounding = rounding;
194		fpi = &fpi1;
195		}
196	k = strtodg(s, sp, fpi, &exp, bits);
197	ULtodd((ULong*)dd, bits, exp, k);
198	return k;
199	}
200