xref: /minix/lib/libc/gdtoa/strtordd.c (revision 00b67f09)
1 /* $NetBSD: strtordd.c,v 1.3 2011/03/20 23:15:35 christos Exp $ */
2 
3 /****************************************************************
4 
5 The author of this software is David M. Gay.
6 
7 Copyright (C) 1998, 2000 by Lucent Technologies
8 All Rights Reserved
9 
10 Permission to use, copy, modify, and distribute this software and
11 its documentation for any purpose and without fee is hereby
12 granted, provided that the above copyright notice appear in all
13 copies and that both that the copyright notice and this
14 permission notice and warranty disclaimer appear in supporting
15 documentation, and that the name of Lucent or any of its entities
16 not be used in advertising or publicity pertaining to
17 distribution of the software without specific, written prior
18 permission.
19 
20 LUCENT DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
21 INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS.
22 IN NO EVENT SHALL LUCENT OR ANY OF ITS ENTITIES BE LIABLE FOR ANY
23 SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
24 WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER
25 IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
26 ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF
27 THIS 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  void
37 #ifdef KR_headers
38 ULtodd(L, bits, expt, k) ULong *L; ULong *bits; Long expt; int k;
39 #else
40 ULtodd(ULong *L, ULong *bits, Long expt, int k)
41 #endif
42 {
43 	int i, j;
44 
45 	switch(k & STRTOG_Retmask) {
46 	  case STRTOG_NoNumber:
47 	  case STRTOG_Zero:
48 		L[0] = L[1] = L[2] = L[3] = 0;
49 		break;
50 
51 	  case STRTOG_Normal:
52 		L[_1] = (bits[1] >> 21 | bits[2] << 11) & (ULong)0xffffffffL;
53 		L[_0] = (bits[2] >> 21) | (bits[3] << 11 & 0xfffff)
54 			  | ((expt + 0x3ff + 105) << 20);
55 		expt += 0x3ff + 52;
56 		if (bits[1] &= 0x1fffff) {
57 			i = hi0bits(bits[1]) - 11;
58 			if (i >= expt) {
59 				i = expt - 1;
60 				expt = 0;
61 				}
62 			else
63 				expt -= i;
64 			if (i > 0) {
65 				bits[1] = bits[1] << i | bits[0] >> (32-i);
66 				bits[0] = bits[0] << i & (ULong)0xffffffffL;
67 				}
68 			}
69 		else if (bits[0]) {
70 			i = hi0bits(bits[0]) + 21;
71 			if (i >= expt) {
72 				i = expt - 1;
73 				expt = 0;
74 				}
75 			else
76 				expt -= i;
77 			if (i < 32) {
78 				bits[1] = bits[0] >> (32 - i);
79 				bits[0] = bits[0] << i & (ULong)0xffffffffL;
80 				}
81 			else {
82 				bits[1] = bits[0] << (i - 32);
83 				bits[0] = 0;
84 				}
85 			}
86 		else {
87 			L[2] = L[3] = 0;
88 			break;
89 			}
90 		L[2+_1] = bits[0];
91 		L[2+_0] = (bits[1] & 0xfffff) | (expt << 20);
92 		break;
93 
94 	  case STRTOG_Denormal:
95 		if (bits[3])
96 			goto nearly_normal;
97 		if (bits[2])
98 			goto partly_normal;
99 		if (bits[1] & 0xffe00000)
100 			goto hardly_normal;
101 		/* completely denormal */
102 		L[2] = L[3] = 0;
103 		L[_1] = bits[0];
104 		L[_0] = bits[1];
105 		break;
106 
107 	  nearly_normal:
108 		i = hi0bits(bits[3]) - 11;	/* i >= 12 */
109 		j = 32 - i;
110 		L[_0] = ((bits[3] << i | bits[2] >> j) & 0xfffff)
111 			| ((65 - i) << 20);
112 		L[_1] = (bits[2] << i | bits[1] >> j) & 0xffffffffL;
113 		L[2+_0] = bits[1] & (((ULong)1L << j) - 1);
114 		L[2+_1] = bits[0];
115 		break;
116 
117 	  partly_normal:
118 		i = hi0bits(bits[2]) - 11;
119 		if (i < 0) {
120 			j = -i;
121 			i += 32;
122 			L[_0] = (bits[2] >> j & 0xfffff) | ((33 + j) << 20);
123 			L[_1] = (bits[2] << i | bits[1] >> j) & 0xffffffffL;
124 			L[2+_0] = bits[1] & (((ULong)1L << j) - 1);
125 			L[2+_1] = bits[0];
126 			break;
127 			}
128 		if (i == 0) {
129 			L[_0] = (bits[2] & 0xfffff) | (33 << 20);
130 			L[_1] = bits[1];
131 			L[2+_0] = 0;
132 			L[2+_1] = bits[0];
133 			break;
134 			}
135 		j = 32 - i;
136 		L[_0] = (((bits[2] << i) | (bits[1] >> j)) & 0xfffff)
137 				| ((j + 1) << 20);
138 		L[_1] = (bits[1] << i | bits[0] >> j) & 0xffffffffL;
139 		L[2+_0] = 0;
140 		L[2+_1] = bits[0] & ((1L << j) - 1);
141 		break;
142 
143 	  hardly_normal:
144 		j = 11 - hi0bits(bits[1]);
145 		i = 32 - j;
146 		L[_0] = (bits[1] >> j & 0xfffff) | ((j + 1) << 20);
147 		L[_1] = (bits[1] << i | bits[0] >> j) & 0xffffffffL;
148 		L[2+_0] = 0;
149 		L[2+_1] = bits[0] & (((ULong)1L << j) - 1);
150 		break;
151 
152 	  case STRTOG_Infinite:
153 		L[_0] = L[2+_0] = 0x7ff00000;
154 		L[_1] = L[2+_1] = 0;
155 		break;
156 
157 	  case STRTOG_NaN:
158 		L[0] = L[2] = d_QNAN0;
159 		L[1] = L[3] = d_QNAN1;
160 		break;
161 
162 	  case STRTOG_NaNbits:
163 		L[_1] = (bits[1] >> 21 | bits[2] << 11) & (ULong)0xffffffffL;
164 		L[_0] = bits[2] >> 21 | bits[3] << 11
165 			  | (ULong)0x7ff00000L;
166 		L[2+_1] = bits[0];
167 		L[2+_0] = bits[1] | (ULong)0x7ff00000L;
168 	  }
169 	if (k & STRTOG_Neg) {
170 		L[_0] |= 0x80000000L;
171 		L[2+_0] |= 0x80000000L;
172 		}
173 	}
174 
175  int
176 #ifdef KR_headers
177 strtordd(s, sp, rounding, dd) CONST char *s; char **sp; int rounding; double *dd;
178 #else
179 strtordd(CONST char *s, char **sp, int rounding, double *dd)
180 #endif
181 {
182 #ifdef Sudden_Underflow
183 	static CONST FPI fpi0 = { 106, 1-1023, 2046-1023-106+1, 1, 1 };
184 #else
185 	static CONST FPI fpi0 = { 106, 1-1023-53+1, 2046-1023-106+1, 1, 0 };
186 #endif
187 	CONST FPI *fpi;
188 	FPI fpi1;
189 	ULong bits[4];
190 	Long expt;
191 	int k;
192 
193 	fpi = &fpi0;
194 	if (rounding != FPI_Round_near) {
195 		fpi1 = fpi0;
196 		fpi1.rounding = rounding;
197 		fpi = &fpi1;
198 		}
199 	k = strtodg(s, sp, fpi, &expt, bits);
200 	if (k == STRTOG_NoMemory)
201 		return k;
202 	ULtodd((ULong*)dd, bits, expt, k);
203 	return k;
204 	}
205