source: vendor/FreeBSD-libc/current/gdtoa/strtordd.c

Last change on this file was 1862, checked in by bird, 21 years ago

Initial revision
  • Property cvs2svn:cvs-rev set to 1.1
  • Property svn:eol-style set to native
  • Property svn:executable set to *
File size: 4.9 KB
Line 
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
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 void
41#ifdef KR_headers
42ULtodd(L, bits, exp, k) ULong *L; ULong *bits; Long exp; int k;
43#else
44ULtodd(ULong *L, ULong *bits, Long exp, int k)
45#endif
46{
47 int i, j;
48
49 switch(k & STRTOG_Retmask) {
50 case STRTOG_NoNumber:
51 case STRTOG_Zero:
52 L[0] = L[1] = L[2] = L[3] = 0;
53 break;
54
55 case STRTOG_Normal:
56 L[_1] = (bits[1] >> 21 | bits[2] << 11) & (ULong)0xffffffffL;
57 L[_0] = bits[2] >> 21 | bits[3] << 11 & 0xfffff
58 | exp + 0x3ff + 105 << 20;
59 exp += 0x3ff + 52;
60 if (bits[1] &= 0x1fffff) {
61 i = hi0bits(bits[1]) - 11;
62 if (i >= exp) {
63 i = exp - 1;
64 exp = 0;
65 }
66 else
67 exp -= i;
68 if (i > 0) {
69 bits[1] = bits[1] << i | bits[0] >> 32-i;
70 bits[0] = bits[0] << i & (ULong)0xffffffffL;
71 }
72 }
73 else if (bits[0]) {
74 i = hi0bits(bits[0]) + 21;
75 if (i >= exp) {
76 i = exp - 1;
77 exp = 0;
78 }
79 else
80 exp -= i;
81 if (i < 32) {
82 bits[1] = bits[0] >> 32 - i;
83 bits[0] = bits[0] << i & (ULong)0xffffffffL;
84 }
85 else {
86 bits[1] = bits[0] << i - 32;
87 bits[0] = 0;
88 }
89 }
90 else {
91 L[2] = L[3] = 0;
92 break;
93 }
94 L[2+_1] = bits[0];
95 L[2+_0] = bits[1] & 0xfffff | exp << 20;
96 break;
97
98 case STRTOG_Denormal:
99 if (bits[3])
100 goto nearly_normal;
101 if (bits[2])
102 goto partly_normal;
103 if (bits[1] & 0xffe00000)
104 goto hardly_normal;
105 /* completely denormal */
106 L[2] = L[3] = 0;
107 L[_1] = bits[0];
108 L[_0] = bits[1];
109 break;
110
111 nearly_normal:
112 i = hi0bits(bits[3]) - 11; /* i >= 12 */
113 j = 32 - i;
114 L[_0] = (bits[3] << i | bits[2] >> j) & 0xfffff
115 | 65 - i << 20;
116 L[_1] = (bits[2] << i | bits[1] >> j) & 0xffffffffL;
117 L[2+_0] = bits[1] & ((ULong)1L << j) - 1;
118 L[2+_1] = bits[0];
119 break;
120
121 partly_normal:
122 i = hi0bits(bits[2]) - 11;
123 if (i < 0) {
124 j = -i;
125 i += 32;
126 L[_0] = bits[2] >> j & 0xfffff | (33 + j) << 20;
127 L[_1] = (bits[2] << i | bits[1] >> j) & 0xffffffffL;
128 L[2+_0] = bits[1] & ((ULong)1L << j) - 1;
129 L[2+_1] = bits[0];
130 break;
131 }
132 if (i == 0) {
133 L[_0] = bits[2] & 0xfffff | 33 << 20;
134 L[_1] = bits[1];
135 L[2+_0] = 0;
136 L[2+_1] = bits[0];
137 break;
138 }
139 j = 32 - i;
140 L[_0] = (bits[2] << i | bits[1] >> j) & 0xfffff
141 | j + 1 << 20;
142 L[_1] = (bits[1] << i | bits[0] >> j) & 0xffffffffL;
143 L[2+_0] = 0;
144 L[2+_1] = bits[0] & (1L << j) - 1;
145 break;
146
147 hardly_normal:
148 j = 11 - hi0bits(bits[1]);
149 i = 32 - j;
150 L[_0] = bits[1] >> j & 0xfffff | j + 1 << 20;
151 L[_1] = (bits[1] << i | bits[0] >> j) & 0xffffffffL;
152 L[2+_0] = 0;
153 L[2+_1] = bits[0] & ((ULong)1L << j) - 1;
154 break;
155
156 case STRTOG_Infinite:
157 L[_0] = L[2+_0] = 0x7ff00000;
158 L[_1] = L[2+_1] = 0;
159 break;
160
161 case STRTOG_NaN:
162 L[_0] = L[2+_0] = 0x7fffffff;
163 L[_1] = L[2+_1] = (ULong)-1;
164 break;
165
166 case STRTOG_NaNbits:
167 L[_1] = (bits[1] >> 21 | bits[2] << 11) & (ULong)0xffffffffL;
168 L[_0] = bits[2] >> 21 | bits[3] << 11
169 | (ULong)0x7ff00000L;
170 L[2+_1] = bits[0];
171 L[2+_0] = bits[1] | (ULong)0x7ff00000L;
172 }
173 if (k & STRTOG_Neg) {
174 L[_0] |= 0x80000000L;
175 L[2+_0] |= 0x80000000L;
176 }
177 }
178
179 int
180#ifdef KR_headers
181strtordd(s, sp, rounding, dd) CONST char *s; char **sp; int rounding; double *dd;
182#else
183strtordd(CONST char *s, char **sp, int rounding, double *dd)
184#endif
185{
186#ifdef Sudden_Underflow
187 static FPI fpi0 = { 106, 1-1023, 2046-1023-106+1, 1, 1 };
188#else
189 static FPI fpi0 = { 106, 1-1023-53+1, 2046-1023-106+1, 1, 0 };
190#endif
191 FPI *fpi, fpi1;
192 ULong bits[4];
193 Long exp;
194 int k;
195
196 fpi = &fpi0;
197 if (rounding != FPI_Round_near) {
198 fpi1 = fpi0;
199 fpi1.rounding = rounding;
200 fpi = &fpi1;
201 }
202 k = strtodg(s, sp, fpi, &exp, bits);
203 ULtodd((ULong*)dd, bits, exp, k);
204 return k;
205 }
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