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1da177e4 LT |
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/fcnvfx.c $Revision: 1.1 $ | |
26 | * | |
27 | * Purpose: | |
28 | * Single Floating-point to Single Fixed-point | |
29 | * Single Floating-point to Double Fixed-point | |
30 | * Double Floating-point to Single Fixed-point | |
31 | * Double Floating-point to Double Fixed-point | |
32 | * | |
33 | * External Interfaces: | |
34 | * dbl_to_dbl_fcnvfx(srcptr,nullptr,dstptr,status) | |
35 | * dbl_to_sgl_fcnvfx(srcptr,nullptr,dstptr,status) | |
36 | * sgl_to_dbl_fcnvfx(srcptr,nullptr,dstptr,status) | |
37 | * sgl_to_sgl_fcnvfx(srcptr,nullptr,dstptr,status) | |
38 | * | |
39 | * Internal Interfaces: | |
40 | * | |
41 | * Theory: | |
42 | * <<please update with a overview of the operation of this file>> | |
43 | * | |
44 | * END_DESC | |
45 | */ | |
46 | ||
47 | ||
48 | #include "float.h" | |
49 | #include "sgl_float.h" | |
50 | #include "dbl_float.h" | |
51 | #include "cnv_float.h" | |
52 | ||
53 | /* | |
54 | * Single Floating-point to Single Fixed-point | |
55 | */ | |
56 | /*ARGSUSED*/ | |
57 | int | |
58 | sgl_to_sgl_fcnvfx( | |
59 | sgl_floating_point *srcptr, | |
60 | sgl_floating_point *nullptr, | |
61 | int *dstptr, | |
62 | sgl_floating_point *status) | |
63 | { | |
64 | register unsigned int src, temp; | |
65 | register int src_exponent, result; | |
66 | register boolean inexact = FALSE; | |
67 | ||
68 | src = *srcptr; | |
69 | src_exponent = Sgl_exponent(src) - SGL_BIAS; | |
70 | ||
71 | /* | |
72 | * Test for overflow | |
73 | */ | |
74 | if (src_exponent > SGL_FX_MAX_EXP) { | |
75 | /* check for MININT */ | |
76 | if ((src_exponent > SGL_FX_MAX_EXP + 1) || | |
77 | Sgl_isnotzero_mantissa(src) || Sgl_iszero_sign(src)) { | |
78 | if (Sgl_iszero_sign(src)) result = 0x7fffffff; | |
79 | else result = 0x80000000; | |
80 | ||
81 | if (Is_invalidtrap_enabled()) { | |
82 | return(INVALIDEXCEPTION); | |
83 | } | |
84 | Set_invalidflag(); | |
85 | *dstptr = result; | |
86 | return(NOEXCEPTION); | |
87 | } | |
88 | } | |
89 | /* | |
90 | * Generate result | |
91 | */ | |
92 | if (src_exponent >= 0) { | |
93 | temp = src; | |
94 | Sgl_clear_signexponent_set_hidden(temp); | |
95 | Int_from_sgl_mantissa(temp,src_exponent); | |
96 | if (Sgl_isone_sign(src)) result = -Sgl_all(temp); | |
97 | else result = Sgl_all(temp); | |
98 | ||
99 | /* check for inexact */ | |
100 | if (Sgl_isinexact_to_fix(src,src_exponent)) { | |
101 | inexact = TRUE; | |
102 | /* round result */ | |
103 | switch (Rounding_mode()) { | |
104 | case ROUNDPLUS: | |
105 | if (Sgl_iszero_sign(src)) result++; | |
106 | break; | |
107 | case ROUNDMINUS: | |
108 | if (Sgl_isone_sign(src)) result--; | |
109 | break; | |
110 | case ROUNDNEAREST: | |
111 | if (Sgl_isone_roundbit(src,src_exponent)) { | |
112 | if (Sgl_isone_stickybit(src,src_exponent) | |
113 | || (Sgl_isone_lowmantissa(temp))) | |
114 | if (Sgl_iszero_sign(src)) result++; | |
115 | else result--; | |
116 | } | |
117 | } | |
118 | } | |
119 | } | |
120 | else { | |
121 | result = 0; | |
122 | ||
123 | /* check for inexact */ | |
124 | if (Sgl_isnotzero_exponentmantissa(src)) { | |
125 | inexact = TRUE; | |
126 | /* round result */ | |
127 | switch (Rounding_mode()) { | |
128 | case ROUNDPLUS: | |
129 | if (Sgl_iszero_sign(src)) result++; | |
130 | break; | |
131 | case ROUNDMINUS: | |
132 | if (Sgl_isone_sign(src)) result--; | |
133 | break; | |
134 | case ROUNDNEAREST: | |
135 | if (src_exponent == -1) | |
136 | if (Sgl_isnotzero_mantissa(src)) | |
137 | if (Sgl_iszero_sign(src)) result++; | |
138 | else result--; | |
139 | } | |
140 | } | |
141 | } | |
142 | *dstptr = result; | |
143 | if (inexact) { | |
144 | if (Is_inexacttrap_enabled()) return(INEXACTEXCEPTION); | |
145 | else Set_inexactflag(); | |
146 | } | |
147 | return(NOEXCEPTION); | |
148 | } | |
149 | ||
150 | /* | |
151 | * Single Floating-point to Double Fixed-point | |
152 | */ | |
153 | /*ARGSUSED*/ | |
154 | int | |
155 | sgl_to_dbl_fcnvfx( | |
156 | sgl_floating_point *srcptr, | |
157 | unsigned int *nullptr, | |
158 | dbl_integer *dstptr, | |
159 | unsigned int *status) | |
160 | { | |
161 | register int src_exponent, resultp1; | |
162 | register unsigned int src, temp, resultp2; | |
163 | register boolean inexact = FALSE; | |
164 | ||
165 | src = *srcptr; | |
166 | src_exponent = Sgl_exponent(src) - SGL_BIAS; | |
167 | ||
168 | /* | |
169 | * Test for overflow | |
170 | */ | |
171 | if (src_exponent > DBL_FX_MAX_EXP) { | |
172 | /* check for MININT */ | |
173 | if ((src_exponent > DBL_FX_MAX_EXP + 1) || | |
174 | Sgl_isnotzero_mantissa(src) || Sgl_iszero_sign(src)) { | |
175 | if (Sgl_iszero_sign(src)) { | |
176 | resultp1 = 0x7fffffff; | |
177 | resultp2 = 0xffffffff; | |
178 | } | |
179 | else { | |
180 | resultp1 = 0x80000000; | |
181 | resultp2 = 0; | |
182 | } | |
183 | if (Is_invalidtrap_enabled()) { | |
184 | return(INVALIDEXCEPTION); | |
185 | } | |
186 | Set_invalidflag(); | |
187 | Dint_copytoptr(resultp1,resultp2,dstptr); | |
188 | return(NOEXCEPTION); | |
189 | } | |
190 | Dint_set_minint(resultp1,resultp2); | |
191 | Dint_copytoptr(resultp1,resultp2,dstptr); | |
192 | return(NOEXCEPTION); | |
193 | } | |
194 | /* | |
195 | * Generate result | |
196 | */ | |
197 | if (src_exponent >= 0) { | |
198 | temp = src; | |
199 | Sgl_clear_signexponent_set_hidden(temp); | |
200 | Dint_from_sgl_mantissa(temp,src_exponent,resultp1,resultp2); | |
201 | if (Sgl_isone_sign(src)) { | |
202 | Dint_setone_sign(resultp1,resultp2); | |
203 | } | |
204 | ||
205 | /* check for inexact */ | |
206 | if (Sgl_isinexact_to_fix(src,src_exponent)) { | |
207 | inexact = TRUE; | |
208 | /* round result */ | |
209 | switch (Rounding_mode()) { | |
210 | case ROUNDPLUS: | |
211 | if (Sgl_iszero_sign(src)) { | |
212 | Dint_increment(resultp1,resultp2); | |
213 | } | |
214 | break; | |
215 | case ROUNDMINUS: | |
216 | if (Sgl_isone_sign(src)) { | |
217 | Dint_decrement(resultp1,resultp2); | |
218 | } | |
219 | break; | |
220 | case ROUNDNEAREST: | |
221 | if (Sgl_isone_roundbit(src,src_exponent)) | |
222 | if (Sgl_isone_stickybit(src,src_exponent) || | |
223 | (Dint_isone_lowp2(resultp2))) | |
224 | if (Sgl_iszero_sign(src)) { | |
225 | Dint_increment(resultp1,resultp2); | |
226 | } | |
227 | else { | |
228 | Dint_decrement(resultp1,resultp2); | |
229 | } | |
230 | } | |
231 | } | |
232 | } | |
233 | else { | |
234 | Dint_setzero(resultp1,resultp2); | |
235 | ||
236 | /* check for inexact */ | |
237 | if (Sgl_isnotzero_exponentmantissa(src)) { | |
238 | inexact = TRUE; | |
239 | /* round result */ | |
240 | switch (Rounding_mode()) { | |
241 | case ROUNDPLUS: | |
242 | if (Sgl_iszero_sign(src)) { | |
243 | Dint_increment(resultp1,resultp2); | |
244 | } | |
245 | break; | |
246 | case ROUNDMINUS: | |
247 | if (Sgl_isone_sign(src)) { | |
248 | Dint_decrement(resultp1,resultp2); | |
249 | } | |
250 | break; | |
251 | case ROUNDNEAREST: | |
252 | if (src_exponent == -1) | |
253 | if (Sgl_isnotzero_mantissa(src)) | |
254 | if (Sgl_iszero_sign(src)) { | |
255 | Dint_increment(resultp1,resultp2); | |
256 | } | |
257 | else { | |
258 | Dint_decrement(resultp1,resultp2); | |
259 | } | |
260 | } | |
261 | } | |
262 | } | |
263 | Dint_copytoptr(resultp1,resultp2,dstptr); | |
264 | if (inexact) { | |
265 | if (Is_inexacttrap_enabled()) return(INEXACTEXCEPTION); | |
266 | else Set_inexactflag(); | |
267 | } | |
268 | return(NOEXCEPTION); | |
269 | } | |
270 | ||
271 | /* | |
272 | * Double Floating-point to Single Fixed-point | |
273 | */ | |
274 | /*ARGSUSED*/ | |
275 | int | |
276 | dbl_to_sgl_fcnvfx( | |
277 | dbl_floating_point *srcptr, | |
278 | unsigned int *nullptr, | |
279 | int *dstptr, | |
280 | unsigned int *status) | |
281 | { | |
282 | register unsigned int srcp1,srcp2, tempp1,tempp2; | |
283 | register int src_exponent, result; | |
284 | register boolean inexact = FALSE; | |
285 | ||
286 | Dbl_copyfromptr(srcptr,srcp1,srcp2); | |
287 | src_exponent = Dbl_exponent(srcp1) - DBL_BIAS; | |
288 | ||
289 | /* | |
290 | * Test for overflow | |
291 | */ | |
292 | if (src_exponent > SGL_FX_MAX_EXP) { | |
293 | /* check for MININT */ | |
294 | if (Dbl_isoverflow_to_int(src_exponent,srcp1,srcp2)) { | |
295 | if (Dbl_iszero_sign(srcp1)) result = 0x7fffffff; | |
296 | else result = 0x80000000; | |
297 | ||
298 | if (Is_invalidtrap_enabled()) { | |
299 | return(INVALIDEXCEPTION); | |
300 | } | |
301 | Set_invalidflag(); | |
302 | *dstptr = result; | |
303 | return(NOEXCEPTION); | |
304 | } | |
305 | } | |
306 | /* | |
307 | * Generate result | |
308 | */ | |
309 | if (src_exponent >= 0) { | |
310 | tempp1 = srcp1; | |
311 | tempp2 = srcp2; | |
312 | Dbl_clear_signexponent_set_hidden(tempp1); | |
313 | Int_from_dbl_mantissa(tempp1,tempp2,src_exponent); | |
314 | if (Dbl_isone_sign(srcp1) && (src_exponent <= SGL_FX_MAX_EXP)) | |
315 | result = -Dbl_allp1(tempp1); | |
316 | else result = Dbl_allp1(tempp1); | |
317 | ||
318 | /* check for inexact */ | |
319 | if (Dbl_isinexact_to_fix(srcp1,srcp2,src_exponent)) { | |
320 | inexact = TRUE; | |
321 | /* round result */ | |
322 | switch (Rounding_mode()) { | |
323 | case ROUNDPLUS: | |
324 | if (Dbl_iszero_sign(srcp1)) result++; | |
325 | break; | |
326 | case ROUNDMINUS: | |
327 | if (Dbl_isone_sign(srcp1)) result--; | |
328 | break; | |
329 | case ROUNDNEAREST: | |
330 | if (Dbl_isone_roundbit(srcp1,srcp2,src_exponent)) | |
331 | if (Dbl_isone_stickybit(srcp1,srcp2,src_exponent) || | |
332 | (Dbl_isone_lowmantissap1(tempp1))) | |
333 | if (Dbl_iszero_sign(srcp1)) result++; | |
334 | else result--; | |
335 | } | |
336 | /* check for overflow */ | |
337 | if ((Dbl_iszero_sign(srcp1) && result < 0) || | |
338 | (Dbl_isone_sign(srcp1) && result > 0)) { | |
339 | ||
340 | if (Dbl_iszero_sign(srcp1)) result = 0x7fffffff; | |
341 | else result = 0x80000000; | |
342 | ||
343 | if (Is_invalidtrap_enabled()) { | |
344 | return(INVALIDEXCEPTION); | |
345 | } | |
346 | Set_invalidflag(); | |
347 | *dstptr = result; | |
348 | return(NOEXCEPTION); | |
349 | } | |
350 | } | |
351 | } | |
352 | else { | |
353 | result = 0; | |
354 | ||
355 | /* check for inexact */ | |
356 | if (Dbl_isnotzero_exponentmantissa(srcp1,srcp2)) { | |
357 | inexact = TRUE; | |
358 | /* round result */ | |
359 | switch (Rounding_mode()) { | |
360 | case ROUNDPLUS: | |
361 | if (Dbl_iszero_sign(srcp1)) result++; | |
362 | break; | |
363 | case ROUNDMINUS: | |
364 | if (Dbl_isone_sign(srcp1)) result--; | |
365 | break; | |
366 | case ROUNDNEAREST: | |
367 | if (src_exponent == -1) | |
368 | if (Dbl_isnotzero_mantissa(srcp1,srcp2)) | |
369 | if (Dbl_iszero_sign(srcp1)) result++; | |
370 | else result--; | |
371 | } | |
372 | } | |
373 | } | |
374 | *dstptr = result; | |
375 | if (inexact) { | |
376 | if (Is_inexacttrap_enabled()) return(INEXACTEXCEPTION); | |
377 | else Set_inexactflag(); | |
378 | } | |
379 | return(NOEXCEPTION); | |
380 | } | |
381 | ||
382 | /* | |
383 | * Double Floating-point to Double Fixed-point | |
384 | */ | |
385 | /*ARGSUSED*/ | |
386 | int | |
387 | dbl_to_dbl_fcnvfx( | |
388 | dbl_floating_point *srcptr, | |
389 | unsigned int *nullptr, | |
390 | dbl_integer *dstptr, | |
391 | unsigned int *status) | |
392 | { | |
393 | register int src_exponent, resultp1; | |
394 | register unsigned int srcp1, srcp2, tempp1, tempp2, resultp2; | |
395 | register boolean inexact = FALSE; | |
396 | ||
397 | Dbl_copyfromptr(srcptr,srcp1,srcp2); | |
398 | src_exponent = Dbl_exponent(srcp1) - DBL_BIAS; | |
399 | ||
400 | /* | |
401 | * Test for overflow | |
402 | */ | |
403 | if (src_exponent > DBL_FX_MAX_EXP) { | |
404 | /* check for MININT */ | |
405 | if ((src_exponent > DBL_FX_MAX_EXP + 1) || | |
406 | Dbl_isnotzero_mantissa(srcp1,srcp2) || Dbl_iszero_sign(srcp1)) { | |
407 | if (Dbl_iszero_sign(srcp1)) { | |
408 | resultp1 = 0x7fffffff; | |
409 | resultp2 = 0xffffffff; | |
410 | } | |
411 | else { | |
412 | resultp1 = 0x80000000; | |
413 | resultp2 = 0; | |
414 | } | |
415 | if (Is_invalidtrap_enabled()) { | |
416 | return(INVALIDEXCEPTION); | |
417 | } | |
418 | Set_invalidflag(); | |
419 | Dint_copytoptr(resultp1,resultp2,dstptr); | |
420 | return(NOEXCEPTION); | |
421 | } | |
422 | } | |
423 | ||
424 | /* | |
425 | * Generate result | |
426 | */ | |
427 | if (src_exponent >= 0) { | |
428 | tempp1 = srcp1; | |
429 | tempp2 = srcp2; | |
430 | Dbl_clear_signexponent_set_hidden(tempp1); | |
431 | Dint_from_dbl_mantissa(tempp1,tempp2,src_exponent,resultp1, | |
432 | resultp2); | |
433 | if (Dbl_isone_sign(srcp1)) { | |
434 | Dint_setone_sign(resultp1,resultp2); | |
435 | } | |
436 | ||
437 | /* check for inexact */ | |
438 | if (Dbl_isinexact_to_fix(srcp1,srcp2,src_exponent)) { | |
439 | inexact = TRUE; | |
440 | /* round result */ | |
441 | switch (Rounding_mode()) { | |
442 | case ROUNDPLUS: | |
443 | if (Dbl_iszero_sign(srcp1)) { | |
444 | Dint_increment(resultp1,resultp2); | |
445 | } | |
446 | break; | |
447 | case ROUNDMINUS: | |
448 | if (Dbl_isone_sign(srcp1)) { | |
449 | Dint_decrement(resultp1,resultp2); | |
450 | } | |
451 | break; | |
452 | case ROUNDNEAREST: | |
453 | if (Dbl_isone_roundbit(srcp1,srcp2,src_exponent)) | |
454 | if (Dbl_isone_stickybit(srcp1,srcp2,src_exponent) || | |
455 | (Dint_isone_lowp2(resultp2))) | |
456 | if (Dbl_iszero_sign(srcp1)) { | |
457 | Dint_increment(resultp1,resultp2); | |
458 | } | |
459 | else { | |
460 | Dint_decrement(resultp1,resultp2); | |
461 | } | |
462 | } | |
463 | } | |
464 | } | |
465 | else { | |
466 | Dint_setzero(resultp1,resultp2); | |
467 | ||
468 | /* check for inexact */ | |
469 | if (Dbl_isnotzero_exponentmantissa(srcp1,srcp2)) { | |
470 | inexact = TRUE; | |
471 | /* round result */ | |
472 | switch (Rounding_mode()) { | |
473 | case ROUNDPLUS: | |
474 | if (Dbl_iszero_sign(srcp1)) { | |
475 | Dint_increment(resultp1,resultp2); | |
476 | } | |
477 | break; | |
478 | case ROUNDMINUS: | |
479 | if (Dbl_isone_sign(srcp1)) { | |
480 | Dint_decrement(resultp1,resultp2); | |
481 | } | |
482 | break; | |
483 | case ROUNDNEAREST: | |
484 | if (src_exponent == -1) | |
485 | if (Dbl_isnotzero_mantissa(srcp1,srcp2)) | |
486 | if (Dbl_iszero_sign(srcp1)) { | |
487 | Dint_increment(resultp1,resultp2); | |
488 | } | |
489 | else { | |
490 | Dint_decrement(resultp1,resultp2); | |
491 | } | |
492 | } | |
493 | } | |
494 | } | |
495 | Dint_copytoptr(resultp1,resultp2,dstptr); | |
496 | if (inexact) { | |
497 | if (Is_inexacttrap_enabled()) return(INEXACTEXCEPTION); | |
498 | else Set_inexactflag(); | |
499 | } | |
500 | return(NOEXCEPTION); | |
501 | } |