fcnvfxt.c revision 1.1 1 1.1 fredette /* $NetBSD: fcnvfxt.c,v 1.1 2002/06/05 01:04:25 fredette 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 1.1 fredette
44 1.1 fredette #include "../spmath/float.h"
45 1.1 fredette #include "../spmath/sgl_float.h"
46 1.1 fredette #include "../spmath/dbl_float.h"
47 1.1 fredette #include "../spmath/cnv_float.h"
48 1.1 fredette
49 1.1 fredette /*
50 1.1 fredette * Convert single floating-point to single fixed-point format
51 1.1 fredette * with truncated result
52 1.1 fredette */
53 1.1 fredette /*ARGSUSED*/
54 1.1 fredette int
55 1.1 fredette sgl_to_sgl_fcnvfxt(srcptr,dstptr,status)
56 1.1 fredette
57 1.1 fredette sgl_floating_point *srcptr;
58 1.1 fredette int *dstptr;
59 1.1 fredette unsigned int *status;
60 1.1 fredette {
61 1.1 fredette register unsigned int src, temp;
62 1.1 fredette register int src_exponent, result;
63 1.1 fredette
64 1.1 fredette src = *srcptr;
65 1.1 fredette src_exponent = Sgl_exponent(src) - SGL_BIAS;
66 1.1 fredette
67 1.1 fredette /*
68 1.1 fredette * Test for overflow
69 1.1 fredette */
70 1.1 fredette if (src_exponent > SGL_FX_MAX_EXP) {
71 1.1 fredette /* check for MININT */
72 1.1 fredette if ((src_exponent > SGL_FX_MAX_EXP + 1) ||
73 1.1 fredette Sgl_isnotzero_mantissa(src) || Sgl_iszero_sign(src)) {
74 1.1 fredette /*
75 1.1 fredette * Since source is a number which cannot be
76 1.1 fredette * represented in fixed-point format, return
77 1.1 fredette * largest (or smallest) fixed-point number.
78 1.1 fredette */
79 1.1 fredette Sgl_return_overflow(src,dstptr);
80 1.1 fredette }
81 1.1 fredette }
82 1.1 fredette /*
83 1.1 fredette * Generate result
84 1.1 fredette */
85 1.1 fredette if (src_exponent >= 0) {
86 1.1 fredette temp = src;
87 1.1 fredette Sgl_clear_signexponent_set_hidden(temp);
88 1.1 fredette Int_from_sgl_mantissa(temp,src_exponent);
89 1.1 fredette if (Sgl_isone_sign(src)) result = -Sgl_all(temp);
90 1.1 fredette else result = Sgl_all(temp);
91 1.1 fredette *dstptr = result;
92 1.1 fredette
93 1.1 fredette /* check for inexact */
94 1.1 fredette if (Sgl_isinexact_to_fix(src,src_exponent)) {
95 1.1 fredette if (Is_inexacttrap_enabled()) return(INEXACTEXCEPTION);
96 1.1 fredette else Set_inexactflag();
97 1.1 fredette }
98 1.1 fredette }
99 1.1 fredette else {
100 1.1 fredette *dstptr = 0;
101 1.1 fredette
102 1.1 fredette /* check for inexact */
103 1.1 fredette if (Sgl_isnotzero_exponentmantissa(src)) {
104 1.1 fredette if (Is_inexacttrap_enabled()) return(INEXACTEXCEPTION);
105 1.1 fredette else Set_inexactflag();
106 1.1 fredette }
107 1.1 fredette }
108 1.1 fredette return(NOEXCEPTION);
109 1.1 fredette }
110 1.1 fredette
111 1.1 fredette /*
112 1.1 fredette * Single Floating-point to Double Fixed-point
113 1.1 fredette */
114 1.1 fredette /*ARGSUSED*/
115 1.1 fredette int
116 1.1 fredette sgl_to_dbl_fcnvfxt(srcptr,dstptr,status)
117 1.1 fredette
118 1.1 fredette sgl_floating_point *srcptr;
119 1.1 fredette dbl_integer *dstptr;
120 1.1 fredette unsigned int *status;
121 1.1 fredette {
122 1.1 fredette register int src_exponent, resultp1;
123 1.1 fredette register unsigned int src, temp, resultp2;
124 1.1 fredette
125 1.1 fredette src = *srcptr;
126 1.1 fredette src_exponent = Sgl_exponent(src) - SGL_BIAS;
127 1.1 fredette
128 1.1 fredette /*
129 1.1 fredette * Test for overflow
130 1.1 fredette */
131 1.1 fredette if (src_exponent > DBL_FX_MAX_EXP) {
132 1.1 fredette /* check for MININT */
133 1.1 fredette if ((src_exponent > DBL_FX_MAX_EXP + 1) ||
134 1.1 fredette Sgl_isnotzero_mantissa(src) || Sgl_iszero_sign(src)) {
135 1.1 fredette /*
136 1.1 fredette * Since source is a number which cannot be
137 1.1 fredette * represented in fixed-point format, return
138 1.1 fredette * largest (or smallest) fixed-point number.
139 1.1 fredette */
140 1.1 fredette Sgl_return_overflow_dbl(src,dstptr);
141 1.1 fredette }
142 1.1 fredette Dint_set_minint(resultp1,resultp2);
143 1.1 fredette Dint_copytoptr(resultp1,resultp2,dstptr);
144 1.1 fredette return(NOEXCEPTION);
145 1.1 fredette }
146 1.1 fredette /*
147 1.1 fredette * Generate result
148 1.1 fredette */
149 1.1 fredette if (src_exponent >= 0) {
150 1.1 fredette temp = src;
151 1.1 fredette Sgl_clear_signexponent_set_hidden(temp);
152 1.1 fredette Dint_from_sgl_mantissa(temp,src_exponent,resultp1,resultp2);
153 1.1 fredette if (Sgl_isone_sign(src)) {
154 1.1 fredette Dint_setone_sign(resultp1,resultp2);
155 1.1 fredette }
156 1.1 fredette Dint_copytoptr(resultp1,resultp2,dstptr);
157 1.1 fredette
158 1.1 fredette /* check for inexact */
159 1.1 fredette if (Sgl_isinexact_to_fix(src,src_exponent)) {
160 1.1 fredette if (Is_inexacttrap_enabled()) return(INEXACTEXCEPTION);
161 1.1 fredette else Set_inexactflag();
162 1.1 fredette }
163 1.1 fredette }
164 1.1 fredette else {
165 1.1 fredette Dint_setzero(resultp1,resultp2);
166 1.1 fredette Dint_copytoptr(resultp1,resultp2,dstptr);
167 1.1 fredette
168 1.1 fredette /* check for inexact */
169 1.1 fredette if (Sgl_isnotzero_exponentmantissa(src)) {
170 1.1 fredette if (Is_inexacttrap_enabled()) return(INEXACTEXCEPTION);
171 1.1 fredette else Set_inexactflag();
172 1.1 fredette }
173 1.1 fredette }
174 1.1 fredette return(NOEXCEPTION);
175 1.1 fredette }
176 1.1 fredette
177 1.1 fredette /*
178 1.1 fredette * Double Floating-point to Single Fixed-point
179 1.1 fredette */
180 1.1 fredette /*ARGSUSED*/
181 1.1 fredette int
182 1.1 fredette dbl_to_sgl_fcnvfxt(srcptr,dstptr,status)
183 1.1 fredette
184 1.1 fredette dbl_floating_point *srcptr;
185 1.1 fredette int *dstptr;
186 1.1 fredette unsigned int *status;
187 1.1 fredette {
188 1.1 fredette register unsigned int srcp1, srcp2, tempp1, tempp2;
189 1.1 fredette register int src_exponent, result;
190 1.1 fredette
191 1.1 fredette Dbl_copyfromptr(srcptr,srcp1,srcp2);
192 1.1 fredette src_exponent = Dbl_exponent(srcp1) - DBL_BIAS;
193 1.1 fredette
194 1.1 fredette /*
195 1.1 fredette * Test for overflow
196 1.1 fredette */
197 1.1 fredette if (src_exponent > SGL_FX_MAX_EXP) {
198 1.1 fredette /* check for MININT */
199 1.1 fredette if (Dbl_isoverflow_to_int(src_exponent,srcp1,srcp2)) {
200 1.1 fredette Dbl_return_overflow(srcp1,srcp2,dstptr);
201 1.1 fredette }
202 1.1 fredette }
203 1.1 fredette /*
204 1.1 fredette * Generate result
205 1.1 fredette */
206 1.1 fredette if (src_exponent >= 0) {
207 1.1 fredette tempp1 = srcp1;
208 1.1 fredette tempp2 = srcp2;
209 1.1 fredette Dbl_clear_signexponent_set_hidden(tempp1);
210 1.1 fredette Int_from_dbl_mantissa(tempp1,tempp2,src_exponent);
211 1.1 fredette if (Dbl_isone_sign(srcp1) && (src_exponent <= SGL_FX_MAX_EXP))
212 1.1 fredette result = -Dbl_allp1(tempp1);
213 1.1 fredette else result = Dbl_allp1(tempp1);
214 1.1 fredette *dstptr = result;
215 1.1 fredette
216 1.1 fredette /* check for inexact */
217 1.1 fredette if (Dbl_isinexact_to_fix(srcp1,srcp2,src_exponent)) {
218 1.1 fredette if (Is_inexacttrap_enabled()) return(INEXACTEXCEPTION);
219 1.1 fredette else Set_inexactflag();
220 1.1 fredette }
221 1.1 fredette }
222 1.1 fredette else {
223 1.1 fredette *dstptr = 0;
224 1.1 fredette
225 1.1 fredette /* check for inexact */
226 1.1 fredette if (Dbl_isnotzero_exponentmantissa(srcp1,srcp2)) {
227 1.1 fredette if (Is_inexacttrap_enabled()) return(INEXACTEXCEPTION);
228 1.1 fredette else Set_inexactflag();
229 1.1 fredette }
230 1.1 fredette }
231 1.1 fredette return(NOEXCEPTION);
232 1.1 fredette }
233 1.1 fredette
234 1.1 fredette /*
235 1.1 fredette * Double Floating-point to Double Fixed-point
236 1.1 fredette */
237 1.1 fredette /*ARGSUSED*/
238 1.1 fredette int
239 1.1 fredette dbl_to_dbl_fcnvfxt(srcptr,dstptr,status)
240 1.1 fredette
241 1.1 fredette dbl_floating_point *srcptr;
242 1.1 fredette dbl_integer *dstptr;
243 1.1 fredette unsigned int *status;
244 1.1 fredette {
245 1.1 fredette register int src_exponent, resultp1;
246 1.1 fredette register unsigned int srcp1, srcp2, tempp1, tempp2, resultp2;
247 1.1 fredette
248 1.1 fredette Dbl_copyfromptr(srcptr,srcp1,srcp2);
249 1.1 fredette src_exponent = Dbl_exponent(srcp1) - DBL_BIAS;
250 1.1 fredette
251 1.1 fredette /*
252 1.1 fredette * Test for overflow
253 1.1 fredette */
254 1.1 fredette if (src_exponent > DBL_FX_MAX_EXP) {
255 1.1 fredette /* check for MININT */
256 1.1 fredette if ((src_exponent > DBL_FX_MAX_EXP + 1) ||
257 1.1 fredette Dbl_isnotzero_mantissa(srcp1,srcp2) || Dbl_iszero_sign(srcp1)) {
258 1.1 fredette /*
259 1.1 fredette * Since source is a number which cannot be
260 1.1 fredette * represented in fixed-point format, return
261 1.1 fredette * largest (or smallest) fixed-point number.
262 1.1 fredette */
263 1.1 fredette Dbl_return_overflow_dbl(srcp1,srcp2,dstptr);
264 1.1 fredette }
265 1.1 fredette }
266 1.1 fredette /*
267 1.1 fredette * Generate result
268 1.1 fredette */
269 1.1 fredette if (src_exponent >= 0) {
270 1.1 fredette tempp1 = srcp1;
271 1.1 fredette tempp2 = srcp2;
272 1.1 fredette Dbl_clear_signexponent_set_hidden(tempp1);
273 1.1 fredette Dint_from_dbl_mantissa(tempp1,tempp2,src_exponent,
274 1.1 fredette resultp1,resultp2);
275 1.1 fredette if (Dbl_isone_sign(srcp1)) {
276 1.1 fredette Dint_setone_sign(resultp1,resultp2);
277 1.1 fredette }
278 1.1 fredette Dint_copytoptr(resultp1,resultp2,dstptr);
279 1.1 fredette
280 1.1 fredette /* check for inexact */
281 1.1 fredette if (Dbl_isinexact_to_fix(srcp1,srcp2,src_exponent)) {
282 1.1 fredette if (Is_inexacttrap_enabled()) return(INEXACTEXCEPTION);
283 1.1 fredette else Set_inexactflag();
284 1.1 fredette }
285 1.1 fredette }
286 1.1 fredette else {
287 1.1 fredette Dint_setzero(resultp1,resultp2);
288 1.1 fredette Dint_copytoptr(resultp1,resultp2,dstptr);
289 1.1 fredette
290 1.1 fredette /* check for inexact */
291 1.1 fredette if (Dbl_isnotzero_exponentmantissa(srcp1,srcp2)) {
292 1.1 fredette if (Is_inexacttrap_enabled()) return(INEXACTEXCEPTION);
293 1.1 fredette else Set_inexactflag();
294 1.1 fredette }
295 1.1 fredette }
296 1.1 fredette return(NOEXCEPTION);
297 1.1 fredette }
298