fcnvfxt.c revision 1.3 1 1.3 christos /* $NetBSD: fcnvfxt.c,v 1.3 2005/12/11 12:17:40 christos Exp $ */
2 1.1 fredette
3 1.1 fredette /* $OpenBSD: fcnvfxt.c,v 1.5 2001/03/29 03:58:18 mickey Exp $ */
4 1.1 fredette
5 1.1 fredette /*
6 1.1 fredette * Copyright 1996 1995 by Open Software Foundation, Inc.
7 1.1 fredette * All Rights Reserved
8 1.1 fredette *
9 1.1 fredette * Permission to use, copy, modify, and distribute this software and
10 1.1 fredette * its documentation for any purpose and without fee is hereby granted,
11 1.1 fredette * provided that the above copyright notice appears in all copies and
12 1.1 fredette * that both the copyright notice and this permission notice appear in
13 1.1 fredette * supporting documentation.
14 1.1 fredette *
15 1.1 fredette * OSF DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE
16 1.1 fredette * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
17 1.1 fredette * FOR A PARTICULAR PURPOSE.
18 1.1 fredette *
19 1.1 fredette * IN NO EVENT SHALL OSF BE LIABLE FOR ANY SPECIAL, INDIRECT, OR
20 1.1 fredette * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
21 1.1 fredette * LOSS OF USE, DATA OR PROFITS, WHETHER IN ACTION OF CONTRACT,
22 1.1 fredette * NEGLIGENCE, OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
23 1.1 fredette * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
24 1.1 fredette *
25 1.1 fredette */
26 1.1 fredette /*
27 1.1 fredette * pmk1.1
28 1.1 fredette */
29 1.1 fredette /*
30 1.1 fredette * (c) Copyright 1986 HEWLETT-PACKARD COMPANY
31 1.1 fredette *
32 1.1 fredette * To anyone who acknowledges that this file is provided "AS IS"
33 1.1 fredette * without any express or implied warranty:
34 1.1 fredette * permission to use, copy, modify, and distribute this file
35 1.1 fredette * for any purpose is hereby granted without fee, provided that
36 1.1 fredette * the above copyright notice and this notice appears in all
37 1.1 fredette * copies, and that the name of Hewlett-Packard Company not be
38 1.1 fredette * used in advertising or publicity pertaining to distribution
39 1.1 fredette * of the software without specific, written prior permission.
40 1.1 fredette * Hewlett-Packard Company makes no representations about the
41 1.1 fredette * suitability of this software for any purpose.
42 1.1 fredette */
43 1.2 lukem
44 1.2 lukem #include <sys/cdefs.h>
45 1.3 christos __KERNEL_RCSID(0, "$NetBSD: fcnvfxt.c,v 1.3 2005/12/11 12:17:40 christos Exp $");
46 1.1 fredette
47 1.1 fredette #include "../spmath/float.h"
48 1.1 fredette #include "../spmath/sgl_float.h"
49 1.1 fredette #include "../spmath/dbl_float.h"
50 1.1 fredette #include "../spmath/cnv_float.h"
51 1.1 fredette
52 1.1 fredette /*
53 1.1 fredette * Convert single floating-point to single fixed-point format
54 1.1 fredette * with truncated result
55 1.1 fredette */
56 1.1 fredette /*ARGSUSED*/
57 1.1 fredette int
58 1.1 fredette sgl_to_sgl_fcnvfxt(srcptr,dstptr,status)
59 1.1 fredette
60 1.1 fredette sgl_floating_point *srcptr;
61 1.1 fredette int *dstptr;
62 1.1 fredette unsigned int *status;
63 1.1 fredette {
64 1.1 fredette register unsigned int src, temp;
65 1.1 fredette register int src_exponent, result;
66 1.1 fredette
67 1.1 fredette src = *srcptr;
68 1.1 fredette src_exponent = Sgl_exponent(src) - SGL_BIAS;
69 1.1 fredette
70 1.1 fredette /*
71 1.1 fredette * Test for overflow
72 1.1 fredette */
73 1.1 fredette if (src_exponent > SGL_FX_MAX_EXP) {
74 1.1 fredette /* check for MININT */
75 1.1 fredette if ((src_exponent > SGL_FX_MAX_EXP + 1) ||
76 1.1 fredette Sgl_isnotzero_mantissa(src) || Sgl_iszero_sign(src)) {
77 1.1 fredette /*
78 1.1 fredette * Since source is a number which cannot be
79 1.1 fredette * represented in fixed-point format, return
80 1.1 fredette * largest (or smallest) fixed-point number.
81 1.1 fredette */
82 1.1 fredette Sgl_return_overflow(src,dstptr);
83 1.1 fredette }
84 1.1 fredette }
85 1.1 fredette /*
86 1.1 fredette * Generate result
87 1.1 fredette */
88 1.1 fredette if (src_exponent >= 0) {
89 1.1 fredette temp = src;
90 1.1 fredette Sgl_clear_signexponent_set_hidden(temp);
91 1.1 fredette Int_from_sgl_mantissa(temp,src_exponent);
92 1.1 fredette if (Sgl_isone_sign(src)) result = -Sgl_all(temp);
93 1.1 fredette else result = Sgl_all(temp);
94 1.1 fredette *dstptr = result;
95 1.1 fredette
96 1.1 fredette /* check for inexact */
97 1.1 fredette if (Sgl_isinexact_to_fix(src,src_exponent)) {
98 1.1 fredette if (Is_inexacttrap_enabled()) return(INEXACTEXCEPTION);
99 1.1 fredette else Set_inexactflag();
100 1.1 fredette }
101 1.1 fredette }
102 1.1 fredette else {
103 1.1 fredette *dstptr = 0;
104 1.1 fredette
105 1.1 fredette /* check for inexact */
106 1.1 fredette if (Sgl_isnotzero_exponentmantissa(src)) {
107 1.1 fredette if (Is_inexacttrap_enabled()) return(INEXACTEXCEPTION);
108 1.1 fredette else Set_inexactflag();
109 1.1 fredette }
110 1.1 fredette }
111 1.1 fredette return(NOEXCEPTION);
112 1.1 fredette }
113 1.1 fredette
114 1.1 fredette /*
115 1.1 fredette * Single Floating-point to Double Fixed-point
116 1.1 fredette */
117 1.1 fredette /*ARGSUSED*/
118 1.1 fredette int
119 1.1 fredette sgl_to_dbl_fcnvfxt(srcptr,dstptr,status)
120 1.1 fredette
121 1.1 fredette sgl_floating_point *srcptr;
122 1.1 fredette dbl_integer *dstptr;
123 1.1 fredette unsigned int *status;
124 1.1 fredette {
125 1.1 fredette register int src_exponent, resultp1;
126 1.1 fredette register unsigned int src, temp, resultp2;
127 1.1 fredette
128 1.1 fredette src = *srcptr;
129 1.1 fredette src_exponent = Sgl_exponent(src) - SGL_BIAS;
130 1.1 fredette
131 1.1 fredette /*
132 1.1 fredette * Test for overflow
133 1.1 fredette */
134 1.1 fredette if (src_exponent > DBL_FX_MAX_EXP) {
135 1.1 fredette /* check for MININT */
136 1.1 fredette if ((src_exponent > DBL_FX_MAX_EXP + 1) ||
137 1.1 fredette Sgl_isnotzero_mantissa(src) || Sgl_iszero_sign(src)) {
138 1.1 fredette /*
139 1.1 fredette * Since source is a number which cannot be
140 1.1 fredette * represented in fixed-point format, return
141 1.1 fredette * largest (or smallest) fixed-point number.
142 1.1 fredette */
143 1.1 fredette Sgl_return_overflow_dbl(src,dstptr);
144 1.1 fredette }
145 1.1 fredette Dint_set_minint(resultp1,resultp2);
146 1.1 fredette Dint_copytoptr(resultp1,resultp2,dstptr);
147 1.1 fredette return(NOEXCEPTION);
148 1.1 fredette }
149 1.1 fredette /*
150 1.1 fredette * Generate result
151 1.1 fredette */
152 1.1 fredette if (src_exponent >= 0) {
153 1.1 fredette temp = src;
154 1.1 fredette Sgl_clear_signexponent_set_hidden(temp);
155 1.1 fredette Dint_from_sgl_mantissa(temp,src_exponent,resultp1,resultp2);
156 1.1 fredette if (Sgl_isone_sign(src)) {
157 1.1 fredette Dint_setone_sign(resultp1,resultp2);
158 1.1 fredette }
159 1.1 fredette Dint_copytoptr(resultp1,resultp2,dstptr);
160 1.1 fredette
161 1.1 fredette /* check for inexact */
162 1.1 fredette if (Sgl_isinexact_to_fix(src,src_exponent)) {
163 1.1 fredette if (Is_inexacttrap_enabled()) return(INEXACTEXCEPTION);
164 1.1 fredette else Set_inexactflag();
165 1.1 fredette }
166 1.1 fredette }
167 1.1 fredette else {
168 1.1 fredette Dint_setzero(resultp1,resultp2);
169 1.1 fredette Dint_copytoptr(resultp1,resultp2,dstptr);
170 1.1 fredette
171 1.1 fredette /* check for inexact */
172 1.1 fredette if (Sgl_isnotzero_exponentmantissa(src)) {
173 1.1 fredette if (Is_inexacttrap_enabled()) return(INEXACTEXCEPTION);
174 1.1 fredette else Set_inexactflag();
175 1.1 fredette }
176 1.1 fredette }
177 1.1 fredette return(NOEXCEPTION);
178 1.1 fredette }
179 1.1 fredette
180 1.1 fredette /*
181 1.1 fredette * Double Floating-point to Single Fixed-point
182 1.1 fredette */
183 1.1 fredette /*ARGSUSED*/
184 1.1 fredette int
185 1.1 fredette dbl_to_sgl_fcnvfxt(srcptr,dstptr,status)
186 1.1 fredette
187 1.1 fredette dbl_floating_point *srcptr;
188 1.1 fredette int *dstptr;
189 1.1 fredette unsigned int *status;
190 1.1 fredette {
191 1.1 fredette register unsigned int srcp1, srcp2, tempp1, tempp2;
192 1.1 fredette register int src_exponent, result;
193 1.1 fredette
194 1.1 fredette Dbl_copyfromptr(srcptr,srcp1,srcp2);
195 1.1 fredette src_exponent = Dbl_exponent(srcp1) - DBL_BIAS;
196 1.1 fredette
197 1.1 fredette /*
198 1.1 fredette * Test for overflow
199 1.1 fredette */
200 1.1 fredette if (src_exponent > SGL_FX_MAX_EXP) {
201 1.1 fredette /* check for MININT */
202 1.1 fredette if (Dbl_isoverflow_to_int(src_exponent,srcp1,srcp2)) {
203 1.1 fredette Dbl_return_overflow(srcp1,srcp2,dstptr);
204 1.1 fredette }
205 1.1 fredette }
206 1.1 fredette /*
207 1.1 fredette * Generate result
208 1.1 fredette */
209 1.1 fredette if (src_exponent >= 0) {
210 1.1 fredette tempp1 = srcp1;
211 1.1 fredette tempp2 = srcp2;
212 1.1 fredette Dbl_clear_signexponent_set_hidden(tempp1);
213 1.1 fredette Int_from_dbl_mantissa(tempp1,tempp2,src_exponent);
214 1.1 fredette if (Dbl_isone_sign(srcp1) && (src_exponent <= SGL_FX_MAX_EXP))
215 1.1 fredette result = -Dbl_allp1(tempp1);
216 1.1 fredette else result = Dbl_allp1(tempp1);
217 1.1 fredette *dstptr = result;
218 1.1 fredette
219 1.1 fredette /* check for inexact */
220 1.1 fredette if (Dbl_isinexact_to_fix(srcp1,srcp2,src_exponent)) {
221 1.1 fredette if (Is_inexacttrap_enabled()) return(INEXACTEXCEPTION);
222 1.1 fredette else Set_inexactflag();
223 1.1 fredette }
224 1.1 fredette }
225 1.1 fredette else {
226 1.1 fredette *dstptr = 0;
227 1.1 fredette
228 1.1 fredette /* check for inexact */
229 1.1 fredette if (Dbl_isnotzero_exponentmantissa(srcp1,srcp2)) {
230 1.1 fredette if (Is_inexacttrap_enabled()) return(INEXACTEXCEPTION);
231 1.1 fredette else Set_inexactflag();
232 1.1 fredette }
233 1.1 fredette }
234 1.1 fredette return(NOEXCEPTION);
235 1.1 fredette }
236 1.1 fredette
237 1.1 fredette /*
238 1.1 fredette * Double Floating-point to Double Fixed-point
239 1.1 fredette */
240 1.1 fredette /*ARGSUSED*/
241 1.1 fredette int
242 1.1 fredette dbl_to_dbl_fcnvfxt(srcptr,dstptr,status)
243 1.1 fredette
244 1.1 fredette dbl_floating_point *srcptr;
245 1.1 fredette dbl_integer *dstptr;
246 1.1 fredette unsigned int *status;
247 1.1 fredette {
248 1.1 fredette register int src_exponent, resultp1;
249 1.1 fredette register unsigned int srcp1, srcp2, tempp1, tempp2, resultp2;
250 1.1 fredette
251 1.1 fredette Dbl_copyfromptr(srcptr,srcp1,srcp2);
252 1.1 fredette src_exponent = Dbl_exponent(srcp1) - DBL_BIAS;
253 1.1 fredette
254 1.1 fredette /*
255 1.1 fredette * Test for overflow
256 1.1 fredette */
257 1.1 fredette if (src_exponent > DBL_FX_MAX_EXP) {
258 1.1 fredette /* check for MININT */
259 1.1 fredette if ((src_exponent > DBL_FX_MAX_EXP + 1) ||
260 1.1 fredette Dbl_isnotzero_mantissa(srcp1,srcp2) || Dbl_iszero_sign(srcp1)) {
261 1.1 fredette /*
262 1.1 fredette * Since source is a number which cannot be
263 1.1 fredette * represented in fixed-point format, return
264 1.1 fredette * largest (or smallest) fixed-point number.
265 1.1 fredette */
266 1.1 fredette Dbl_return_overflow_dbl(srcp1,srcp2,dstptr);
267 1.1 fredette }
268 1.1 fredette }
269 1.1 fredette /*
270 1.1 fredette * Generate result
271 1.1 fredette */
272 1.1 fredette if (src_exponent >= 0) {
273 1.1 fredette tempp1 = srcp1;
274 1.1 fredette tempp2 = srcp2;
275 1.1 fredette Dbl_clear_signexponent_set_hidden(tempp1);
276 1.1 fredette Dint_from_dbl_mantissa(tempp1,tempp2,src_exponent,
277 1.1 fredette resultp1,resultp2);
278 1.1 fredette if (Dbl_isone_sign(srcp1)) {
279 1.1 fredette Dint_setone_sign(resultp1,resultp2);
280 1.1 fredette }
281 1.1 fredette Dint_copytoptr(resultp1,resultp2,dstptr);
282 1.1 fredette
283 1.1 fredette /* check for inexact */
284 1.1 fredette if (Dbl_isinexact_to_fix(srcp1,srcp2,src_exponent)) {
285 1.1 fredette if (Is_inexacttrap_enabled()) return(INEXACTEXCEPTION);
286 1.1 fredette else Set_inexactflag();
287 1.1 fredette }
288 1.1 fredette }
289 1.1 fredette else {
290 1.1 fredette Dint_setzero(resultp1,resultp2);
291 1.1 fredette Dint_copytoptr(resultp1,resultp2,dstptr);
292 1.1 fredette
293 1.1 fredette /* check for inexact */
294 1.1 fredette if (Dbl_isnotzero_exponentmantissa(srcp1,srcp2)) {
295 1.1 fredette if (Is_inexacttrap_enabled()) return(INEXACTEXCEPTION);
296 1.1 fredette else Set_inexactflag();
297 1.1 fredette }
298 1.1 fredette }
299 1.1 fredette return(NOEXCEPTION);
300 1.1 fredette }
301