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Diffstat (limited to 'arch/parisc/math-emu/fcnvff.c')
-rw-r--r-- | arch/parisc/math-emu/fcnvff.c | 309 |
1 files changed, 309 insertions, 0 deletions
diff --git a/arch/parisc/math-emu/fcnvff.c b/arch/parisc/math-emu/fcnvff.c new file mode 100644 index 000000000000..76c063f7d17c --- /dev/null +++ b/arch/parisc/math-emu/fcnvff.c | |||
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1 | /* | ||
2 | * Linux/PA-RISC Project (http://www.parisc-linux.org/) | ||
3 | * | ||
4 | * Floating-point emulation code | ||
5 | * Copyright (C) 2001 Hewlett-Packard (Paul Bame) <bame@debian.org> | ||
6 | * | ||
7 | * This program is free software; you can redistribute it and/or modify | ||
8 | * it under the terms of the GNU General Public License as published by | ||
9 | * the Free Software Foundation; either version 2, or (at your option) | ||
10 | * any later version. | ||
11 | * | ||
12 | * This program is distributed in the hope that it will be useful, | ||
13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | ||
14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | ||
15 | * GNU General Public License for more details. | ||
16 | * | ||
17 | * You should have received a copy of the GNU General Public License | ||
18 | * along with this program; if not, write to the Free Software | ||
19 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | ||
20 | */ | ||
21 | /* | ||
22 | * BEGIN_DESC | ||
23 | * | ||
24 | * File: | ||
25 | * @(#) pa/spmath/fcnvff.c $Revision: 1.1 $ | ||
26 | * | ||
27 | * Purpose: | ||
28 | * Single Floating-point to Double Floating-point | ||
29 | * Double Floating-point to Single Floating-point | ||
30 | * | ||
31 | * External Interfaces: | ||
32 | * dbl_to_sgl_fcnvff(srcptr,nullptr,dstptr,status) | ||
33 | * sgl_to_dbl_fcnvff(srcptr,nullptr,dstptr,status) | ||
34 | * | ||
35 | * Internal Interfaces: | ||
36 | * | ||
37 | * Theory: | ||
38 | * <<please update with a overview of the operation of this file>> | ||
39 | * | ||
40 | * END_DESC | ||
41 | */ | ||
42 | |||
43 | |||
44 | #include "float.h" | ||
45 | #include "sgl_float.h" | ||
46 | #include "dbl_float.h" | ||
47 | #include "cnv_float.h" | ||
48 | |||
49 | /* | ||
50 | * Single Floating-point to Double Floating-point | ||
51 | */ | ||
52 | /*ARGSUSED*/ | ||
53 | int | ||
54 | sgl_to_dbl_fcnvff( | ||
55 | sgl_floating_point *srcptr, | ||
56 | unsigned int *nullptr, | ||
57 | dbl_floating_point *dstptr, | ||
58 | unsigned int *status) | ||
59 | { | ||
60 | register unsigned int src, resultp1, resultp2; | ||
61 | register int src_exponent; | ||
62 | |||
63 | src = *srcptr; | ||
64 | src_exponent = Sgl_exponent(src); | ||
65 | Dbl_allp1(resultp1) = Sgl_all(src); /* set sign of result */ | ||
66 | /* | ||
67 | * Test for NaN or infinity | ||
68 | */ | ||
69 | if (src_exponent == SGL_INFINITY_EXPONENT) { | ||
70 | /* | ||
71 | * determine if NaN or infinity | ||
72 | */ | ||
73 | if (Sgl_iszero_mantissa(src)) { | ||
74 | /* | ||
75 | * is infinity; want to return double infinity | ||
76 | */ | ||
77 | Dbl_setinfinity_exponentmantissa(resultp1,resultp2); | ||
78 | Dbl_copytoptr(resultp1,resultp2,dstptr); | ||
79 | return(NOEXCEPTION); | ||
80 | } | ||
81 | else { | ||
82 | /* | ||
83 | * is NaN; signaling or quiet? | ||
84 | */ | ||
85 | if (Sgl_isone_signaling(src)) { | ||
86 | /* trap if INVALIDTRAP enabled */ | ||
87 | if (Is_invalidtrap_enabled()) | ||
88 | return(INVALIDEXCEPTION); | ||
89 | /* make NaN quiet */ | ||
90 | else { | ||
91 | Set_invalidflag(); | ||
92 | Sgl_set_quiet(src); | ||
93 | } | ||
94 | } | ||
95 | /* | ||
96 | * NaN is quiet, return as double NaN | ||
97 | */ | ||
98 | Dbl_setinfinity_exponent(resultp1); | ||
99 | Sgl_to_dbl_mantissa(src,resultp1,resultp2); | ||
100 | Dbl_copytoptr(resultp1,resultp2,dstptr); | ||
101 | return(NOEXCEPTION); | ||
102 | } | ||
103 | } | ||
104 | /* | ||
105 | * Test for zero or denormalized | ||
106 | */ | ||
107 | if (src_exponent == 0) { | ||
108 | /* | ||
109 | * determine if zero or denormalized | ||
110 | */ | ||
111 | if (Sgl_isnotzero_mantissa(src)) { | ||
112 | /* | ||
113 | * is denormalized; want to normalize | ||
114 | */ | ||
115 | Sgl_clear_signexponent(src); | ||
116 | Sgl_leftshiftby1(src); | ||
117 | Sgl_normalize(src,src_exponent); | ||
118 | Sgl_to_dbl_exponent(src_exponent,resultp1); | ||
119 | Sgl_to_dbl_mantissa(src,resultp1,resultp2); | ||
120 | } | ||
121 | else { | ||
122 | Dbl_setzero_exponentmantissa(resultp1,resultp2); | ||
123 | } | ||
124 | Dbl_copytoptr(resultp1,resultp2,dstptr); | ||
125 | return(NOEXCEPTION); | ||
126 | } | ||
127 | /* | ||
128 | * No special cases, just complete the conversion | ||
129 | */ | ||
130 | Sgl_to_dbl_exponent(src_exponent, resultp1); | ||
131 | Sgl_to_dbl_mantissa(Sgl_mantissa(src), resultp1,resultp2); | ||
132 | Dbl_copytoptr(resultp1,resultp2,dstptr); | ||
133 | return(NOEXCEPTION); | ||
134 | } | ||
135 | |||
136 | /* | ||
137 | * Double Floating-point to Single Floating-point | ||
138 | */ | ||
139 | /*ARGSUSED*/ | ||
140 | int | ||
141 | dbl_to_sgl_fcnvff( | ||
142 | dbl_floating_point *srcptr, | ||
143 | unsigned int *nullptr, | ||
144 | sgl_floating_point *dstptr, | ||
145 | unsigned int *status) | ||
146 | { | ||
147 | register unsigned int srcp1, srcp2, result; | ||
148 | register int src_exponent, dest_exponent, dest_mantissa; | ||
149 | register boolean inexact = FALSE, guardbit = FALSE, stickybit = FALSE; | ||
150 | register boolean lsb_odd = FALSE; | ||
151 | boolean is_tiny; | ||
152 | |||
153 | Dbl_copyfromptr(srcptr,srcp1,srcp2); | ||
154 | src_exponent = Dbl_exponent(srcp1); | ||
155 | Sgl_all(result) = Dbl_allp1(srcp1); /* set sign of result */ | ||
156 | /* | ||
157 | * Test for NaN or infinity | ||
158 | */ | ||
159 | if (src_exponent == DBL_INFINITY_EXPONENT) { | ||
160 | /* | ||
161 | * determine if NaN or infinity | ||
162 | */ | ||
163 | if (Dbl_iszero_mantissa(srcp1,srcp2)) { | ||
164 | /* | ||
165 | * is infinity; want to return single infinity | ||
166 | */ | ||
167 | Sgl_setinfinity_exponentmantissa(result); | ||
168 | *dstptr = result; | ||
169 | return(NOEXCEPTION); | ||
170 | } | ||
171 | /* | ||
172 | * is NaN; signaling or quiet? | ||
173 | */ | ||
174 | if (Dbl_isone_signaling(srcp1)) { | ||
175 | /* trap if INVALIDTRAP enabled */ | ||
176 | if (Is_invalidtrap_enabled()) return(INVALIDEXCEPTION); | ||
177 | else { | ||
178 | Set_invalidflag(); | ||
179 | /* make NaN quiet */ | ||
180 | Dbl_set_quiet(srcp1); | ||
181 | } | ||
182 | } | ||
183 | /* | ||
184 | * NaN is quiet, return as single NaN | ||
185 | */ | ||
186 | Sgl_setinfinity_exponent(result); | ||
187 | Sgl_set_mantissa(result,Dallp1(srcp1)<<3 | Dallp2(srcp2)>>29); | ||
188 | if (Sgl_iszero_mantissa(result)) Sgl_set_quiet(result); | ||
189 | *dstptr = result; | ||
190 | return(NOEXCEPTION); | ||
191 | } | ||
192 | /* | ||
193 | * Generate result | ||
194 | */ | ||
195 | Dbl_to_sgl_exponent(src_exponent,dest_exponent); | ||
196 | if (dest_exponent > 0) { | ||
197 | Dbl_to_sgl_mantissa(srcp1,srcp2,dest_mantissa,inexact,guardbit, | ||
198 | stickybit,lsb_odd); | ||
199 | } | ||
200 | else { | ||
201 | if (Dbl_iszero_exponentmantissa(srcp1,srcp2)){ | ||
202 | Sgl_setzero_exponentmantissa(result); | ||
203 | *dstptr = result; | ||
204 | return(NOEXCEPTION); | ||
205 | } | ||
206 | if (Is_underflowtrap_enabled()) { | ||
207 | Dbl_to_sgl_mantissa(srcp1,srcp2,dest_mantissa,inexact, | ||
208 | guardbit,stickybit,lsb_odd); | ||
209 | } | ||
210 | else { | ||
211 | /* compute result, determine inexact info, | ||
212 | * and set Underflowflag if appropriate | ||
213 | */ | ||
214 | Dbl_to_sgl_denormalized(srcp1,srcp2,dest_exponent, | ||
215 | dest_mantissa,inexact,guardbit,stickybit,lsb_odd, | ||
216 | is_tiny); | ||
217 | } | ||
218 | } | ||
219 | /* | ||
220 | * Now round result if not exact | ||
221 | */ | ||
222 | if (inexact) { | ||
223 | switch (Rounding_mode()) { | ||
224 | case ROUNDPLUS: | ||
225 | if (Sgl_iszero_sign(result)) dest_mantissa++; | ||
226 | break; | ||
227 | case ROUNDMINUS: | ||
228 | if (Sgl_isone_sign(result)) dest_mantissa++; | ||
229 | break; | ||
230 | case ROUNDNEAREST: | ||
231 | if (guardbit) { | ||
232 | if (stickybit || lsb_odd) dest_mantissa++; | ||
233 | } | ||
234 | } | ||
235 | } | ||
236 | Sgl_set_exponentmantissa(result,dest_mantissa); | ||
237 | |||
238 | /* | ||
239 | * check for mantissa overflow after rounding | ||
240 | */ | ||
241 | if ((dest_exponent>0 || Is_underflowtrap_enabled()) && | ||
242 | Sgl_isone_hidden(result)) dest_exponent++; | ||
243 | |||
244 | /* | ||
245 | * Test for overflow | ||
246 | */ | ||
247 | if (dest_exponent >= SGL_INFINITY_EXPONENT) { | ||
248 | /* trap if OVERFLOWTRAP enabled */ | ||
249 | if (Is_overflowtrap_enabled()) { | ||
250 | /* | ||
251 | * Check for gross overflow | ||
252 | */ | ||
253 | if (dest_exponent >= SGL_INFINITY_EXPONENT+SGL_WRAP) | ||
254 | return(UNIMPLEMENTEDEXCEPTION); | ||
255 | |||
256 | /* | ||
257 | * Adjust bias of result | ||
258 | */ | ||
259 | Sgl_setwrapped_exponent(result,dest_exponent,ovfl); | ||
260 | *dstptr = result; | ||
261 | if (inexact) | ||
262 | if (Is_inexacttrap_enabled()) | ||
263 | return(OVERFLOWEXCEPTION|INEXACTEXCEPTION); | ||
264 | else Set_inexactflag(); | ||
265 | return(OVERFLOWEXCEPTION); | ||
266 | } | ||
267 | Set_overflowflag(); | ||
268 | inexact = TRUE; | ||
269 | /* set result to infinity or largest number */ | ||
270 | Sgl_setoverflow(result); | ||
271 | } | ||
272 | /* | ||
273 | * Test for underflow | ||
274 | */ | ||
275 | else if (dest_exponent <= 0) { | ||
276 | /* trap if UNDERFLOWTRAP enabled */ | ||
277 | if (Is_underflowtrap_enabled()) { | ||
278 | /* | ||
279 | * Check for gross underflow | ||
280 | */ | ||
281 | if (dest_exponent <= -(SGL_WRAP)) | ||
282 | return(UNIMPLEMENTEDEXCEPTION); | ||
283 | /* | ||
284 | * Adjust bias of result | ||
285 | */ | ||
286 | Sgl_setwrapped_exponent(result,dest_exponent,unfl); | ||
287 | *dstptr = result; | ||
288 | if (inexact) | ||
289 | if (Is_inexacttrap_enabled()) | ||
290 | return(UNDERFLOWEXCEPTION|INEXACTEXCEPTION); | ||
291 | else Set_inexactflag(); | ||
292 | return(UNDERFLOWEXCEPTION); | ||
293 | } | ||
294 | /* | ||
295 | * result is denormalized or signed zero | ||
296 | */ | ||
297 | if (inexact && is_tiny) Set_underflowflag(); | ||
298 | |||
299 | } | ||
300 | else Sgl_set_exponent(result,dest_exponent); | ||
301 | *dstptr = result; | ||
302 | /* | ||
303 | * Trap if inexact trap is enabled | ||
304 | */ | ||
305 | if (inexact) | ||
306 | if (Is_inexacttrap_enabled()) return(INEXACTEXCEPTION); | ||
307 | else Set_inexactflag(); | ||
308 | return(NOEXCEPTION); | ||
309 | } | ||