| blob | 7356a4a5580e5fa67b5d1895a8d5d6437b294fc0 |
1 /*
2 * fp_util.S
3 *
4 * Copyright Roman Zippel, 1997. All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, and the entire permission notice in its entirety,
11 * including the disclaimer of warranties.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. The name of the author may not be used to endorse or promote
16 * products derived from this software without specific prior
17 * written permission.
18 *
19 * ALTERNATIVELY, this product may be distributed under the terms of
20 * the GNU Public License, in which case the provisions of the GPL are
21 * required INSTEAD OF the above restrictions. (This clause is
22 * necessary due to a potential bad interaction between the GPL and
23 * the restrictions contained in a BSD-style copyright.)
24 *
25 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
26 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
27 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
28 * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
29 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
30 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
31 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
32 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
33 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
34 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
35 * OF THE POSSIBILITY OF SUCH DAMAGE.
36 */
38 #include "fp_emu.h"
40 /*
41 * Here are lots of conversion and normalization functions mainly
42 * used by fp_scan.S
43 * Note that these functions are optimized for "normal" numbers,
44 * these are handled first and exit as fast as possible, this is
45 * especially important for fp_normalize_ext/fp_conv_ext2ext, as
46 * it's called very often.
47 * The register usage is optimized for fp_scan.S and which register
48 * is currently at that time unused, be careful if you want change
49 * something here. %d0 and %d1 is always usable, sometimes %d2 (or
50 * only the lower half) most function have to return the %a0
51 * unmodified, so that the caller can immediatly reuse it.
52 */
54 .globl fp_ill, fp_end
56 | exits from fp_scan:
57 | illegal instruction
58 fp_ill:
59 printf ,"fp_illegal\n"
60 rts
61 | completed instruction
62 fp_end:
63 tst.l (TASK_MM-8,%a2)
64 jmi 1f
65 tst.l (TASK_MM-4,%a2)
66 jmi 1f
67 tst.l (TASK_MM,%a2)
68 jpl 2f
69 1: printf ,"oops:%p,%p,%p\n",3,%a2@(TASK_MM-8),%a2@(TASK_MM-4),%a2@(TASK_MM)
70 2: clr.l %d0
71 rts
73 .globl fp_conv_long2ext, fp_conv_single2ext
74 .globl fp_conv_double2ext, fp_conv_ext2ext
75 .globl fp_normalize_ext, fp_normalize_double
76 .globl fp_normalize_single, fp_normalize_single_fast
77 .globl fp_conv_ext2double, fp_conv_ext2single
78 .globl fp_conv_ext2long, fp_conv_ext2short
79 .globl fp_conv_ext2byte
80 .globl fp_finalrounding_single, fp_finalrounding_single_fast
81 .globl fp_finalrounding_double
82 .globl fp_finalrounding, fp_finaltest, fp_final
84 /*
85 * First several conversion functions from a source operand
86 * into the extended format. Note, that only fp_conv_ext2ext
87 * normalizes the number and is always called after the other
88 * conversion functions, which only move the information into
89 * fp_ext structure.
90 */
92 | fp_conv_long2ext:
93 |
94 | args: %d0 = source (32-bit long)
95 | %a0 = destination (ptr to struct fp_ext)
97 fp_conv_long2ext:
98 printf PCONV,"l2e: %p -> %p(",2,%d0,%a0
99 clr.l %d1 | sign defaults to zero
100 tst.l %d0
101 jeq fp_l2e_zero | is source zero?
102 jpl 1f | positive?
103 moveq #1,%d1
104 neg.l %d0
105 1: swap %d1
106 move.w #0x3fff+31,%d1
107 move.l %d1,(%a0)+ | set sign / exp
108 move.l %d0,(%a0)+ | set mantissa
109 clr.l (%a0)
110 subq.l #8,%a0 | restore %a0
111 printx PCONV,%a0@
112 printf PCONV,")\n"
113 rts
114 | source is zero
115 fp_l2e_zero:
116 clr.l (%a0)+
117 clr.l (%a0)+
118 clr.l (%a0)
119 subq.l #8,%a0
120 printx PCONV,%a0@
121 printf PCONV,")\n"
122 rts
124 | fp_conv_single2ext
125 | args: %d0 = source (single-precision fp value)
126 | %a0 = dest (struct fp_ext *)
128 fp_conv_single2ext:
129 printf PCONV,"s2e: %p -> %p(",2,%d0,%a0
130 move.l %d0,%d1
131 lsl.l #8,%d0 | shift mantissa
132 lsr.l #8,%d1 | exponent / sign
133 lsr.l #7,%d1
134 lsr.w #8,%d1
135 jeq fp_s2e_small | zero / denormal?
136 cmp.w #0xff,%d1 | NaN / Inf?
137 jeq fp_s2e_large
138 bset #31,%d0 | set explizit bit
139 add.w #0x3fff-0x7f,%d1 | re-bias the exponent.
140 9: move.l %d1,(%a0)+ | fp_ext.sign, fp_ext.exp
141 move.l %d0,(%a0)+ | high lword of fp_ext.mant
142 clr.l (%a0) | low lword = 0
143 subq.l #8,%a0
144 printx PCONV,%a0@
145 printf PCONV,")\n"
146 rts
147 | zeros and denormalized
148 fp_s2e_small:
149 | exponent is zero, so explizit bit is already zero too
150 tst.l %d0
151 jeq 9b
152 move.w #0x4000-0x7f,%d1
153 jra 9b
154 | infinities and NAN
155 fp_s2e_large:
156 bclr #31,%d0 | clear explizit bit
157 move.w #0x7fff,%d1
158 jra 9b
160 fp_conv_double2ext:
161 #ifdef FPU_EMU_DEBUG
162 getuser.l %a1@(0),%d0,fp_err_ua2,%a1
163 getuser.l %a1@(4),%d1,fp_err_ua2,%a1
164 printf PCONV,"d2e: %p%p -> %p(",3,%d0,%d1,%a0
165 #endif
166 getuser.l (%a1)+,%d0,fp_err_ua2,%a1
167 move.l %d0,%d1
168 lsl.l #8,%d0 | shift high mantissa
169 lsl.l #3,%d0
170 lsr.l #8,%d1 | exponent / sign
171 lsr.l #7,%d1
172 lsr.w #5,%d1
173 jeq fp_d2e_small | zero / denormal?
174 cmp.w #0x7ff,%d1 | NaN / Inf?
175 jeq fp_d2e_large
176 bset #31,%d0 | set explizit bit
177 add.w #0x3fff-0x3ff,%d1 | re-bias the exponent.
178 9: move.l %d1,(%a0)+ | fp_ext.sign, fp_ext.exp
179 move.l %d0,(%a0)+
180 getuser.l (%a1)+,%d0,fp_err_ua2,%a1
181 move.l %d0,%d1
182 lsl.l #8,%d0
183 lsl.l #3,%d0
184 move.l %d0,(%a0)
185 moveq #21,%d0
186 lsr.l %d0,%d1
187 or.l %d1,-(%a0)
188 subq.l #4,%a0
189 printx PCONV,%a0@
190 printf PCONV,")\n"
191 rts
192 | zeros and denormalized
193 fp_d2e_small:
194 | exponent is zero, so explizit bit is already zero too
195 tst.l %d0
196 jeq 9b
197 move.w #0x4000-0x3ff,%d1
198 jra 9b
199 | infinities and NAN
200 fp_d2e_large:
201 bclr #31,%d0 | clear explizit bit
202 move.w #0x7fff,%d1
203 jra 9b
205 | fp_conv_ext2ext:
206 | originally used to get longdouble from userspace, now it's
207 | called before arithmetic operations to make sure the number
208 | is normalized [maybe rename it?].
209 | args: %a0 = dest (struct fp_ext *)
210 | returns 0 in %d0 for a NaN, otherwise 1
212 fp_conv_ext2ext:
213 printf PCONV,"e2e: %p(",1,%a0
214 printx PCONV,%a0@
215 printf PCONV,"), "
216 move.l (%a0)+,%d0
217 cmp.w #0x7fff,%d0 | Inf / NaN?
218 jeq fp_e2e_large
219 move.l (%a0),%d0
220 jpl fp_e2e_small | zero / denorm?
221 | The high bit is set, so normalization is irrelevant.
222 fp_e2e_checkround:
223 subq.l #4,%a0
224 #ifdef CONFIG_M68KFPU_EMU_EXTRAPREC
225 move.b (%a0),%d0
226 jne fp_e2e_round
227 #endif
228 printf PCONV,"%p(",1,%a0
229 printx PCONV,%a0@
230 printf PCONV,")\n"
231 moveq #1,%d0
232 rts
233 #ifdef CONFIG_M68KFPU_EMU_EXTRAPREC
234 fp_e2e_round:
235 fp_set_sr FPSR_EXC_INEX2
236 clr.b (%a0)
237 move.w (FPD_RND,FPDATA),%d2
238 jne fp_e2e_roundother | %d2 == 0, round to nearest
239 tst.b %d0 | test guard bit
240 jpl 9f | zero is closer
241 btst #0,(11,%a0) | test lsb bit
242 jne fp_e2e_doroundup | round to infinity
243 lsl.b #1,%d0 | check low bits
244 jeq 9f | round to zero
245 fp_e2e_doroundup:
246 addq.l #1,(8,%a0)
247 jcc 9f
248 addq.l #1,(4,%a0)
249 jcc 9f
250 move.w #0x8000,(4,%a0)
251 addq.w #1,(2,%a0)
252 9: printf PNORM,"%p(",1,%a0
253 printx PNORM,%a0@
254 printf PNORM,")\n"
255 rts
256 fp_e2e_roundother:
257 subq.w #2,%d2
258 jcs 9b | %d2 < 2, round to zero
259 jhi 1f | %d2 > 2, round to +infinity
260 tst.b (1,%a0) | to -inf
261 jne fp_e2e_doroundup | negative, round to infinity
262 jra 9b | positive, round to zero
263 1: tst.b (1,%a0) | to +inf
264 jeq fp_e2e_doroundup | positive, round to infinity
265 jra 9b | negative, round to zero
266 #endif
267 | zeros and subnormals:
268 | try to normalize these anyway.
269 fp_e2e_small:
270 jne fp_e2e_small1 | high lword zero?
271 move.l (4,%a0),%d0
272 jne fp_e2e_small2
273 #ifdef CONFIG_M68KFPU_EMU_EXTRAPREC
274 clr.l %d0
275 move.b (-4,%a0),%d0
276 jne fp_e2e_small3
277 #endif
278 | Genuine zero.
279 clr.w -(%a0)
280 subq.l #2,%a0
281 printf PNORM,"%p(",1,%a0
282 printx PNORM,%a0@
283 printf PNORM,")\n"
284 moveq #1,%d0
285 rts
286 | definitely subnormal, need to shift all 64 bits
287 fp_e2e_small1:
288 bfffo %d0{#0,#32},%d1
289 move.w -(%a0),%d2
290 sub.w %d1,%d2
291 jcc 1f
292 | Pathologically small, denormalize.
293 add.w %d2,%d1
294 clr.w %d2
295 1: move.w %d2,(%a0)+
296 move.w %d1,%d2
297 jeq fp_e2e_checkround
298 | fancy 64-bit double-shift begins here
299 lsl.l %d2,%d0
300 move.l %d0,(%a0)+
301 move.l (%a0),%d0
302 move.l %d0,%d1
303 lsl.l %d2,%d0
304 move.l %d0,(%a0)
305 neg.w %d2
306 and.w #0x1f,%d2
307 lsr.l %d2,%d1
308 or.l %d1,-(%a0)
309 #ifdef CONFIG_M68KFPU_EMU_EXTRAPREC
310 fp_e2e_extra1:
311 clr.l %d0
312 move.b (-4,%a0),%d0
313 neg.w %d2
314 add.w #24,%d2
315 jcc 1f
316 clr.b (-4,%a0)
317 lsl.l %d2,%d0
318 or.l %d0,(4,%a0)
319 jra fp_e2e_checkround
320 1: addq.w #8,%d2
321 lsl.l %d2,%d0
322 move.b %d0,(-4,%a0)
323 lsr.l #8,%d0
324 or.l %d0,(4,%a0)
325 #endif
326 jra fp_e2e_checkround
327 | pathologically small subnormal
328 fp_e2e_small2:
329 bfffo %d0{#0,#32},%d1
330 add.w #32,%d1
331 move.w -(%a0),%d2
332 sub.w %d1,%d2
333 jcc 1f
334 | Beyond pathologically small, denormalize.
335 add.w %d2,%d1
336 clr.w %d2
337 1: move.w %d2,(%a0)+
338 ext.l %d1
339 jeq fp_e2e_checkround
340 clr.l (4,%a0)
341 sub.w #32,%d2
342 jcs 1f
343 lsl.l %d1,%d0 | lower lword needs only to be shifted
344 move.l %d0,(%a0) | into the higher lword
345 #ifdef CONFIG_M68KFPU_EMU_EXTRAPREC
346 clr.l %d0
347 move.b (-4,%a0),%d0
348 clr.b (-4,%a0)
349 neg.w %d1
350 add.w #32,%d1
351 bfins %d0,(%a0){%d1,#8}
352 #endif
353 jra fp_e2e_checkround
354 1: neg.w %d1 | lower lword is splitted between
355 bfins %d0,(%a0){%d1,#32} | higher and lower lword
356 #ifndef CONFIG_M68KFPU_EMU_EXTRAPREC
357 jra fp_e2e_checkround
358 #else
359 move.w %d1,%d2
360 jra fp_e2e_extra1
361 | These are extremely small numbers, that will mostly end up as zero
362 | anyway, so this is only important for correct rounding.
363 fp_e2e_small3:
364 bfffo %d0{#24,#8},%d1
365 add.w #40,%d1
366 move.w -(%a0),%d2
367 sub.w %d1,%d2
368 jcc 1f
369 | Pathologically small, denormalize.
370 add.w %d2,%d1
371 clr.w %d2
372 1: move.w %d2,(%a0)+
373 ext.l %d1
374 jeq fp_e2e_checkround
375 cmp.w #8,%d1
376 jcs 2f
377 1: clr.b (-4,%a0)
378 sub.w #64,%d1
379 jcs 1f
380 add.w #24,%d1
381 lsl.l %d1,%d0
382 move.l %d0,(%a0)
383 jra fp_e2e_checkround
384 1: neg.w %d1
385 bfins %d0,(%a0){%d1,#8}
386 jra fp_e2e_checkround
387 2: lsl.l %d1,%d0
388 move.b %d0,(-4,%a0)
389 lsr.l #8,%d0
390 move.b %d0,(7,%a0)
391 jra fp_e2e_checkround
392 #endif
393 1: move.l %d0,%d1 | lower lword is splitted between
394 lsl.l %d2,%d0 | higher and lower lword
395 move.l %d0,(%a0)
396 move.l %d1,%d0
397 neg.w %d2
398 add.w #32,%d2
399 lsr.l %d2,%d0
400 move.l %d0,-(%a0)
401 jra fp_e2e_checkround
402 | Infinities and NaNs
403 fp_e2e_large:
404 move.l (%a0)+,%d0
405 jne 3f
406 1: tst.l (%a0)
407 jne 4f
408 moveq #1,%d0
409 2: subq.l #8,%a0
410 printf PCONV,"%p(",1,%a0
411 printx PCONV,%a0@
412 printf PCONV,")\n"
413 rts
414 | we have maybe a NaN, shift off the highest bit
415 3: lsl.l #1,%d0
416 jeq 1b
417 | we have a NaN, clear the return value
418 4: clrl %d0
419 jra 2b
422 /*
423 * Normalization functions. Call these on the output of general
424 * FP operators, and before any conversion into the destination
425 * formats. fp_normalize_ext has always to be called first, the
426 * following conversion functions expect an already normalized
427 * number.
428 */
430 | fp_normalize_ext:
431 | normalize an extended in extended (unpacked) format, basically
432 | it does the same as fp_conv_ext2ext, additionally it also does
433 | the necessary postprocessing checks.
434 | args: %a0 (struct fp_ext *)
435 | NOTE: it does _not_ modify %a0/%a1 and the upper word of %d2
437 fp_normalize_ext:
438 printf PNORM,"ne: %p(",1,%a0
439 printx PNORM,%a0@
440 printf PNORM,"), "
441 move.l (%a0)+,%d0
442 cmp.w #0x7fff,%d0 | Inf / NaN?
443 jeq fp_ne_large
444 move.l (%a0),%d0
445 jpl fp_ne_small | zero / denorm?
446 | The high bit is set, so normalization is irrelevant.
447 fp_ne_checkround:
448 subq.l #4,%a0
449 #ifdef CONFIG_M68KFPU_EMU_EXTRAPREC
450 move.b (%a0),%d0
451 jne fp_ne_round
452 #endif
453 printf PNORM,"%p(",1,%a0
454 printx PNORM,%a0@
455 printf PNORM,")\n"
456 rts
457 #ifdef CONFIG_M68KFPU_EMU_EXTRAPREC
458 fp_ne_round:
459 fp_set_sr FPSR_EXC_INEX2
460 clr.b (%a0)
461 move.w (FPD_RND,FPDATA),%d2
462 jne fp_ne_roundother | %d2 == 0, round to nearest
463 tst.b %d0 | test guard bit
464 jpl 9f | zero is closer
465 btst #0,(11,%a0) | test lsb bit
466 jne fp_ne_doroundup | round to infinity
467 lsl.b #1,%d0 | check low bits
468 jeq 9f | round to zero
469 fp_ne_doroundup:
470 addq.l #1,(8,%a0)
471 jcc 9f
472 addq.l #1,(4,%a0)
473 jcc 9f
474 addq.w #1,(2,%a0)
475 move.w #0x8000,(4,%a0)
476 9: printf PNORM,"%p(",1,%a0
477 printx PNORM,%a0@
478 printf PNORM,")\n"
479 rts
480 fp_ne_roundother:
481 subq.w #2,%d2
482 jcs 9b | %d2 < 2, round to zero
483 jhi 1f | %d2 > 2, round to +infinity
484 tst.b (1,%a0) | to -inf
485 jne fp_ne_doroundup | negative, round to infinity
486 jra 9b | positive, round to zero
487 1: tst.b (1,%a0) | to +inf
488 jeq fp_ne_doroundup | positive, round to infinity
489 jra 9b | negative, round to zero
490 #endif
491 | Zeros and subnormal numbers
492 | These are probably merely subnormal, rather than "denormalized"
493 | numbers, so we will try to make them normal again.
494 fp_ne_small:
495 jne fp_ne_small1 | high lword zero?
496 move.l (4,%a0),%d0
497 jne fp_ne_small2
498 #ifdef CONFIG_M68KFPU_EMU_EXTRAPREC
499 clr.l %d0
500 move.b (-4,%a0),%d0
501 jne fp_ne_small3
502 #endif
503 | Genuine zero.
504 clr.w -(%a0)
505 subq.l #2,%a0
506 printf PNORM,"%p(",1,%a0
507 printx PNORM,%a0@
508 printf PNORM,")\n"
509 rts
510 | Subnormal.
511 fp_ne_small1:
512 bfffo %d0{#0,#32},%d1
513 move.w -(%a0),%d2
514 sub.w %d1,%d2
515 jcc 1f
516 | Pathologically small, denormalize.
517 add.w %d2,%d1
518 clr.w %d2
519 fp_set_sr FPSR_EXC_UNFL
520 1: move.w %d2,(%a0)+
521 move.w %d1,%d2
522 jeq fp_ne_checkround
523 | This is exactly the same 64-bit double shift as seen above.
524 lsl.l %d2,%d0
525 move.l %d0,(%a0)+
526 move.l (%a0),%d0
527 move.l %d0,%d1
528 lsl.l %d2,%d0
529 move.l %d0,(%a0)
530 neg.w %d2
531 and.w #0x1f,%d2
532 lsr.l %d2,%d1
533 or.l %d1,-(%a0)
534 #ifdef CONFIG_M68KFPU_EMU_EXTRAPREC
535 fp_ne_extra1:
536 clr.l %d0
537 move.b (-4,%a0),%d0
538 neg.w %d2
539 add.w #24,%d2
540 jcc 1f
541 clr.b (-4,%a0)
542 lsl.l %d2,%d0
543 or.l %d0,(4,%a0)
544 jra fp_ne_checkround
545 1: addq.w #8,%d2
546 lsl.l %d2,%d0
547 move.b %d0,(-4,%a0)
548 lsr.l #8,%d0
549 or.l %d0,(4,%a0)
550 #endif
551 jra fp_ne_checkround
552 | May or may not be subnormal, if so, only 32 bits to shift.
553 fp_ne_small2:
554 bfffo %d0{#0,#32},%d1
555 add.w #32,%d1
556 move.w -(%a0),%d2
557 sub.w %d1,%d2
558 jcc 1f
559 | Beyond pathologically small, denormalize.
560 add.w %d2,%d1
561 clr.w %d2
562 fp_set_sr FPSR_EXC_UNFL
563 1: move.w %d2,(%a0)+
564 ext.l %d1
565 jeq fp_ne_checkround
566 clr.l (4,%a0)
567 sub.w #32,%d1
568 jcs 1f
569 lsl.l %d1,%d0 | lower lword needs only to be shifted
570 move.l %d0,(%a0) | into the higher lword
571 #ifdef CONFIG_M68KFPU_EMU_EXTRAPREC
572 clr.l %d0
573 move.b (-4,%a0),%d0
574 clr.b (-4,%a0)
575 neg.w %d1
576 add.w #32,%d1
577 bfins %d0,(%a0){%d1,#8}
578 #endif
579 jra fp_ne_checkround
580 1: neg.w %d1 | lower lword is splitted between
581 bfins %d0,(%a0){%d1,#32} | higher and lower lword
582 #ifndef CONFIG_M68KFPU_EMU_EXTRAPREC
583 jra fp_ne_checkround
584 #else
585 move.w %d1,%d2
586 jra fp_ne_extra1
587 | These are extremely small numbers, that will mostly end up as zero
588 | anyway, so this is only important for correct rounding.
589 fp_ne_small3:
590 bfffo %d0{#24,#8},%d1
591 add.w #40,%d1
592 move.w -(%a0),%d2
593 sub.w %d1,%d2
594 jcc 1f
595 | Pathologically small, denormalize.
596 add.w %d2,%d1
597 clr.w %d2
598 1: move.w %d2,(%a0)+
599 ext.l %d1
600 jeq fp_ne_checkround
601 cmp.w #8,%d1
602 jcs 2f
603 1: clr.b (-4,%a0)
604 sub.w #64,%d1
605 jcs 1f
606 add.w #24,%d1
607 lsl.l %d1,%d0
608 move.l %d0,(%a0)
609 jra fp_ne_checkround
610 1: neg.w %d1
611 bfins %d0,(%a0){%d1,#8}
612 jra fp_ne_checkround
613 2: lsl.l %d1,%d0
614 move.b %d0,(-4,%a0)
615 lsr.l #8,%d0
616 move.b %d0,(7,%a0)
617 jra fp_ne_checkround
618 #endif
619 | Infinities and NaNs, again, same as above.
620 fp_ne_large:
621 move.l (%a0)+,%d0
622 jne 3f
623 1: tst.l (%a0)
624 jne 4f
625 2: subq.l #8,%a0
626 printf PNORM,"%p(",1,%a0
627 printx PNORM,%a0@
628 printf PNORM,")\n"
629 rts
630 | we have maybe a NaN, shift off the highest bit
631 3: move.l %d0,%d1
632 lsl.l #1,%d1
633 jne 4f
634 clr.l (-4,%a0)
635 jra 1b
636 | we have a NaN, test if it is signaling
637 4: bset #30,%d0
638 jne 2b
639 fp_set_sr FPSR_EXC_SNAN
640 move.l %d0,(-4,%a0)
641 jra 2b
643 | these next two do rounding as per the IEEE standard.
644 | values for the rounding modes appear to be:
645 | 0: Round to nearest
646 | 1: Round to zero
647 | 2: Round to -Infinity
648 | 3: Round to +Infinity
649 | both functions expect that fp_normalize was already
650 | called (and extended argument is already normalized
651 | as far as possible), these are used if there is different
652 | rounding precision is selected and before converting
653 | into single/double
655 | fp_normalize_double:
656 | normalize an extended with double (52-bit) precision
657 | args: %a0 (struct fp_ext *)
659 fp_normalize_double:
660 printf PNORM,"nd: %p(",1,%a0
661 printx PNORM,%a0@
662 printf PNORM,"), "
663 move.l (%a0)+,%d2
664 tst.w %d2
665 jeq fp_nd_zero | zero / denormalized
666 cmp.w #0x7fff,%d2
667 jeq fp_nd_huge | NaN / infinitive.
668 sub.w #0x4000-0x3ff,%d2 | will the exponent fit?
669 jcs fp_nd_small | too small.
670 cmp.w #0x7fe,%d2
671 jcc fp_nd_large | too big.
672 addq.l #4,%a0
673 move.l (%a0),%d0 | low lword of mantissa
674 | now, round off the low 11 bits.
675 fp_nd_round:
676 moveq #21,%d1
677 lsl.l %d1,%d0 | keep 11 low bits.
678 jne fp_nd_checkround | Are they non-zero?
679 | nothing to do here
680 9: subq.l #8,%a0
681 printf PNORM,"%p(",1,%a0
682 printx PNORM,%a0@
683 printf PNORM,")\n"
684 rts
685 | Be careful with the X bit! It contains the lsb
686 | from the shift above, it is needed for round to nearest.
687 fp_nd_checkround:
688 fp_set_sr FPSR_EXC_INEX2 | INEX2 bit
689 and.w #0xf800,(2,%a0) | clear bits 0-10
690 move.w (FPD_RND,FPDATA),%d2 | rounding mode
691 jne 2f | %d2 == 0, round to nearest
692 tst.l %d0 | test guard bit
693 jpl 9b | zero is closer
694 | here we test the X bit by adding it to %d2
695 clr.w %d2 | first set z bit, addx only clears it
696 addx.w %d2,%d2 | test lsb bit
697 | IEEE754-specified "round to even" behaviour. If the guard
698 | bit is set, then the number is odd, so rounding works like
699 | in grade-school arithmetic (i.e. 1.5 rounds to 2.0)
700 | Otherwise, an equal distance rounds towards zero, so as not
701 | to produce an odd number. This is strange, but it is what
702 | the standard says.
703 jne fp_nd_doroundup | round to infinity
704 lsl.l #1,%d0 | check low bits
705 jeq 9b | round to zero
706 fp_nd_doroundup:
707 | round (the mantissa, that is) towards infinity
708 add.l #0x800,(%a0)
709 jcc 9b | no overflow, good.
710 addq.l #1,-(%a0) | extend to high lword
711 jcc 1f | no overflow, good.
712 | Yow! we have managed to overflow the mantissa. Since this
713 | only happens when %d1 was 0xfffff800, it is now zero, so
714 | reset the high bit, and increment the exponent.
715 move.w #0x8000,(%a0)
716 addq.w #1,-(%a0)
717 cmp.w #0x43ff,(%a0)+ | exponent now overflown?
718 jeq fp_nd_large | yes, so make it infinity.
719 1: subq.l #4,%a0
720 printf PNORM,"%p(",1,%a0
721 printx PNORM,%a0@
722 printf PNORM,")\n"
723 rts
724 2: subq.w #2,%d2
725 jcs 9b | %d2 < 2, round to zero
726 jhi 3f | %d2 > 2, round to +infinity
727 | Round to +Inf or -Inf. High word of %d2 contains the
728 | sign of the number, by the way.
729 swap %d2 | to -inf
730 tst.b %d2
731 jne fp_nd_doroundup | negative, round to infinity
732 jra 9b | positive, round to zero
733 3: swap %d2 | to +inf
734 tst.b %d2
735 jeq fp_nd_doroundup | positive, round to infinity
736 jra 9b | negative, round to zero
737 | Exponent underflow. Try to make a denormal, and set it to
738 | the smallest possible fraction if this fails.
739 fp_nd_small:
740 fp_set_sr FPSR_EXC_UNFL | set UNFL bit
741 move.w #0x3c01,(-2,%a0) | 2**-1022
742 neg.w %d2 | degree of underflow
743 cmp.w #32,%d2 | single or double shift?
744 jcc 1f
745 | Again, another 64-bit double shift.
746 move.l (%a0),%d0
747 move.l %d0,%d1
748 lsr.l %d2,%d0
749 move.l %d0,(%a0)+
750 move.l (%a0),%d0
751 lsr.l %d2,%d0
752 neg.w %d2
753 add.w #32,%d2
754 lsl.l %d2,%d1
755 or.l %d1,%d0
756 move.l (%a0),%d1
757 move.l %d0,(%a0)
758 | Check to see if we shifted off any significant bits
759 lsl.l %d2,%d1
760 jeq fp_nd_round | Nope, round.
761 bset #0,%d0 | Yes, so set the "sticky bit".
762 jra fp_nd_round | Now, round.
763 | Another 64-bit single shift and store
764 1: sub.w #32,%d2
765 cmp.w #32,%d2 | Do we really need to shift?
766 jcc 2f | No, the number is too small.
767 move.l (%a0),%d0
768 clr.l (%a0)+
769 move.l %d0,%d1
770 lsr.l %d2,%d0
771 neg.w %d2
772 add.w #32,%d2
773 | Again, check to see if we shifted off any significant bits.
774 tst.l (%a0)
775 jeq 1f
776 bset #0,%d0 | Sticky bit.
777 1: move.l %d0,(%a0)
778 lsl.l %d2,%d1
779 jeq fp_nd_round
780 bset #0,%d0
781 jra fp_nd_round
782 | Sorry, the number is just too small.
783 2: clr.l (%a0)+
784 clr.l (%a0)
785 moveq #1,%d0 | Smallest possible fraction,
786 jra fp_nd_round | round as desired.
787 | zero and denormalized
788 fp_nd_zero:
789 tst.l (%a0)+
790 jne 1f
791 tst.l (%a0)
792 jne 1f
793 subq.l #8,%a0
794 printf PNORM,"%p(",1,%a0
795 printx PNORM,%a0@
796 printf PNORM,")\n"
797 rts | zero. nothing to do.
798 | These are not merely subnormal numbers, but true denormals,
799 | i.e. pathologically small (exponent is 2**-16383) numbers.
800 | It is clearly impossible for even a normal extended number
801 | with that exponent to fit into double precision, so just
802 | write these ones off as "too darn small".
803 1: fp_set_sr FPSR_EXC_UNFL | Set UNFL bit
804 clr.l (%a0)
805 clr.l -(%a0)
806 move.w #0x3c01,-(%a0) | i.e. 2**-1022
807 addq.l #6,%a0
808 moveq #1,%d0
809 jra fp_nd_round | round.
810 | Exponent overflow. Just call it infinity.
811 fp_nd_large:
812 move.w #0x7ff,%d0
813 and.w (6,%a0),%d0
814 jeq 1f
815 fp_set_sr FPSR_EXC_INEX2
816 1: fp_set_sr FPSR_EXC_OVFL
817 move.w (FPD_RND,FPDATA),%d2
818 jne 3f | %d2 = 0 round to nearest
819 1: move.w #0x7fff,(-2,%a0)
820 clr.l (%a0)+
821 clr.l (%a0)
822 2: subq.l #8,%a0
823 printf PNORM,"%p(",1,%a0
824 printx PNORM,%a0@
825 printf PNORM,")\n"
826 rts
827 3: subq.w #2,%d2
828 jcs 5f | %d2 < 2, round to zero
829 jhi 4f | %d2 > 2, round to +infinity
830 tst.b (-3,%a0) | to -inf
831 jne 1b
832 jra 5f
833 4: tst.b (-3,%a0) | to +inf
834 jeq 1b
835 5: move.w #0x43fe,(-2,%a0)
836 moveq #-1,%d0
837 move.l %d0,(%a0)+
838 move.w #0xf800,%d0
839 move.l %d0,(%a0)
840 jra 2b
841 | Infinities or NaNs
842 fp_nd_huge:
843 subq.l #4,%a0
844 printf PNORM,"%p(",1,%a0
845 printx PNORM,%a0@
846 printf PNORM,")\n"
847 rts
849 | fp_normalize_single:
850 | normalize an extended with single (23-bit) precision
851 | args: %a0 (struct fp_ext *)
853 fp_normalize_single:
854 printf PNORM,"ns: %p(",1,%a0
855 printx PNORM,%a0@
856 printf PNORM,") "
857 addq.l #2,%a0
858 move.w (%a0)+,%d2
859 jeq fp_ns_zero | zero / denormalized
860 cmp.w #0x7fff,%d2
861 jeq fp_ns_huge | NaN / infinitive.
862 sub.w #0x4000-0x7f,%d2 | will the exponent fit?
863 jcs fp_ns_small | too small.
864 cmp.w #0xfe,%d2
865 jcc fp_ns_large | too big.
866 move.l (%a0)+,%d0 | get high lword of mantissa
867 fp_ns_round:
868 tst.l (%a0) | check the low lword
869 jeq 1f
870 | Set a sticky bit if it is non-zero. This should only
871 | affect the rounding in what would otherwise be equal-
872 | distance situations, which is what we want it to do.
873 bset #0,%d0
874 1: clr.l (%a0) | zap it from memory.
875 | now, round off the low 8 bits of the hi lword.
876 tst.b %d0 | 8 low bits.
877 jne fp_ns_checkround | Are they non-zero?
878 | nothing to do here
879 subq.l #8,%a0
880 printf PNORM,"%p(",1,%a0
881 printx PNORM,%a0@
882 printf PNORM,")\n"
883 rts
884 fp_ns_checkround:
885 fp_set_sr FPSR_EXC_INEX2 | INEX2 bit
886 clr.b -(%a0) | clear low byte of high lword
887 subq.l #3,%a0
888 move.w (FPD_RND,FPDATA),%d2 | rounding mode
889 jne 2f | %d2 == 0, round to nearest
890 tst.b %d0 | test guard bit
891 jpl 9f | zero is closer
892 btst #8,%d0 | test lsb bit
893 | round to even behaviour, see above.
894 jne fp_ns_doroundup | round to infinity
895 lsl.b #1,%d0 | check low bits
896 jeq 9f | round to zero
897 fp_ns_doroundup:
898 | round (the mantissa, that is) towards infinity
899 add.l #0x100,(%a0)
900 jcc 9f | no overflow, good.
901 | Overflow. This means that the %d1 was 0xffffff00, so it
902 | is now zero. We will set the mantissa to reflect this, and
903 | increment the exponent (checking for overflow there too)
904 move.w #0x8000,(%a0)
905 addq.w #1,-(%a0)
906 cmp.w #0x407f,(%a0)+ | exponent now overflown?
907 jeq fp_ns_large | yes, so make it infinity.
908 9: subq.l #4,%a0
909 printf PNORM,"%p(",1,%a0
910 printx PNORM,%a0@
911 printf PNORM,")\n"
912 rts
913 | check nondefault rounding modes
914 2: subq.w #2,%d2
915 jcs 9b | %d2 < 2, round to zero
916 jhi 3f | %d2 > 2, round to +infinity
917 tst.b (-3,%a0) | to -inf
918 jne fp_ns_doroundup | negative, round to infinity
919 jra 9b | positive, round to zero
920 3: tst.b (-3,%a0) | to +inf
921 jeq fp_ns_doroundup | positive, round to infinity
922 jra 9b | negative, round to zero
923 | Exponent underflow. Try to make a denormal, and set it to
924 | the smallest possible fraction if this fails.
925 fp_ns_small:
926 fp_set_sr FPSR_EXC_UNFL | set UNFL bit
927 move.w #0x3f81,(-2,%a0) | 2**-126
928 neg.w %d2 | degree of underflow
929 cmp.w #32,%d2 | single or double shift?
930 jcc 2f
931 | a 32-bit shift.
932 move.l (%a0),%d0
933 move.l %d0,%d1
934 lsr.l %d2,%d0
935 move.l %d0,(%a0)+
936 | Check to see if we shifted off any significant bits.
937 neg.w %d2
938 add.w #32,%d2
939 lsl.l %d2,%d1
940 jeq 1f
941 bset #0,%d0 | Sticky bit.
942 | Check the lower lword
943 1: tst.l (%a0)
944 jeq fp_ns_round
945 clr (%a0)
946 bset #0,%d0 | Sticky bit.
947 jra fp_ns_round
948 | Sorry, the number is just too small.
949 2: clr.l (%a0)+
950 clr.l (%a0)
951 moveq #1,%d0 | Smallest possible fraction,
952 jra fp_ns_round | round as desired.
953 | Exponent overflow. Just call it infinity.
954 fp_ns_large:
955 tst.b (3,%a0)
956 jeq 1f
957 fp_set_sr FPSR_EXC_INEX2
958 1: fp_set_sr FPSR_EXC_OVFL
959 move.w (FPD_RND,FPDATA),%d2
960 jne 3f | %d2 = 0 round to nearest
961 1: move.w #0x7fff,(-2,%a0)
962 clr.l (%a0)+
963 clr.l (%a0)
964 2: subq.l #8,%a0
965 printf PNORM,"%p(",1,%a0
966 printx PNORM,%a0@
967 printf PNORM,")\n"
968 rts
969 3: subq.w #2,%d2
970 jcs 5f | %d2 < 2, round to zero
971 jhi 4f | %d2 > 2, round to +infinity
972 tst.b (-3,%a0) | to -inf
973 jne 1b
974 jra 5f
975 4: tst.b (-3,%a0) | to +inf
976 jeq 1b
977 5: move.w #0x407e,(-2,%a0)
978 move.l #0xffffff00,(%a0)+
979 clr.l (%a0)
980 jra 2b
981 | zero and denormalized
982 fp_ns_zero:
983 tst.l (%a0)+
984 jne 1f
985 tst.l (%a0)
986 jne 1f
987 subq.l #8,%a0
988 printf PNORM,"%p(",1,%a0
989 printx PNORM,%a0@
990 printf PNORM,")\n"
991 rts | zero. nothing to do.
992 | These are not merely subnormal numbers, but true denormals,
993 | i.e. pathologically small (exponent is 2**-16383) numbers.
994 | It is clearly impossible for even a normal extended number
995 | with that exponent to fit into single precision, so just
996 | write these ones off as "too darn small".
997 1: fp_set_sr FPSR_EXC_UNFL | Set UNFL bit
998 clr.l (%a0)
999 clr.l -(%a0)
1000 move.w #0x3f81,-(%a0) | i.e. 2**-126
1001 addq.l #6,%a0
1002 moveq #1,%d0
1003 jra fp_ns_round | round.
1004 | Infinities or NaNs
1005 fp_ns_huge:
1006 subq.l #4,%a0
1007 printf PNORM,"%p(",1,%a0
1008 printx PNORM,%a0@
1009 printf PNORM,")\n"
1010 rts
1012 | fp_normalize_single_fast:
1013 | normalize an extended with single (23-bit) precision
1014 | this is only used by fsgldiv/fsgdlmul, where the
1015 | operand is not completly normalized.
1016 | args: %a0 (struct fp_ext *)
1018 fp_normalize_single_fast:
1019 printf PNORM,"nsf: %p(",1,%a0
1020 printx PNORM,%a0@
1021 printf PNORM,") "
1022 addq.l #2,%a0
1023 move.w (%a0)+,%d2
1024 cmp.w #0x7fff,%d2
1025 jeq fp_nsf_huge | NaN / infinitive.
1026 move.l (%a0)+,%d0 | get high lword of mantissa
1027 fp_nsf_round:
1028 tst.l (%a0) | check the low lword
1029 jeq 1f
1030 | Set a sticky bit if it is non-zero. This should only
1031 | affect the rounding in what would otherwise be equal-
1032 | distance situations, which is what we want it to do.
1033 bset #0,%d0
1034 1: clr.l (%a0) | zap it from memory.
1035 | now, round off the low 8 bits of the hi lword.
1036 tst.b %d0 | 8 low bits.
1037 jne fp_nsf_checkround | Are they non-zero?
1038 | nothing to do here
1039 subq.l #8,%a0
1040 printf PNORM,"%p(",1,%a0
1041 printx PNORM,%a0@
1042 printf PNORM,")\n"
1043 rts
1044 fp_nsf_checkround:
1045 fp_set_sr FPSR_EXC_INEX2 | INEX2 bit
1046 clr.b -(%a0) | clear low byte of high lword
1047 subq.l #3,%a0
1048 move.w (FPD_RND,FPDATA),%d2 | rounding mode
1049 jne 2f | %d2 == 0, round to nearest
1050 tst.b %d0 | test guard bit
1051 jpl 9f | zero is closer
1052 btst #8,%d0 | test lsb bit
1053 | round to even behaviour, see above.
1054 jne fp_nsf_doroundup | round to infinity
1055 lsl.b #1,%d0 | check low bits
1056 jeq 9f | round to zero
1057 fp_nsf_doroundup:
1058 | round (the mantissa, that is) towards infinity
1059 add.l #0x100,(%a0)
1060 jcc 9f | no overflow, good.
1061 | Overflow. This means that the %d1 was 0xffffff00, so it
1062 | is now zero. We will set the mantissa to reflect this, and
1063 | increment the exponent (checking for overflow there too)
1064 move.w #0x8000,(%a0)
1065 addq.w #1,-(%a0)
1066 cmp.w #0x407f,(%a0)+ | exponent now overflown?
1067 jeq fp_nsf_large | yes, so make it infinity.
1068 9: subq.l #4,%a0
1069 printf PNORM,"%p(",1,%a0
1070 printx PNORM,%a0@
1071 printf PNORM,")\n"
1072 rts
1073 | check nondefault rounding modes
1074 2: subq.w #2,%d2
1075 jcs 9b | %d2 < 2, round to zero
1076 jhi 3f | %d2 > 2, round to +infinity
1077 tst.b (-3,%a0) | to -inf
1078 jne fp_nsf_doroundup | negative, round to infinity
1079 jra 9b | positive, round to zero
1080 3: tst.b (-3,%a0) | to +inf
1081 jeq fp_nsf_doroundup | positive, round to infinity
1082 jra 9b | negative, round to zero
1083 | Exponent overflow. Just call it infinity.
1084 fp_nsf_large:
1085 tst.b (3,%a0)
1086 jeq 1f
1087 fp_set_sr FPSR_EXC_INEX2
1088 1: fp_set_sr FPSR_EXC_OVFL
1089 move.w (FPD_RND,FPDATA),%d2
1090 jne 3f | %d2 = 0 round to nearest
1091 1: move.w #0x7fff,(-2,%a0)
1092 clr.l (%a0)+
1093 clr.l (%a0)
1094 2: subq.l #8,%a0
1095 printf PNORM,"%p(",1,%a0
1096 printx PNORM,%a0@
1097 printf PNORM,")\n"
1098 rts
1099 3: subq.w #2,%d2
1100 jcs 5f | %d2 < 2, round to zero
1101 jhi 4f | %d2 > 2, round to +infinity
1102 tst.b (-3,%a0) | to -inf
1103 jne 1b
1104 jra 5f
1105 4: tst.b (-3,%a0) | to +inf
1106 jeq 1b
1107 5: move.w #0x407e,(-2,%a0)
1108 move.l #0xffffff00,(%a0)+
1109 clr.l (%a0)
1110 jra 2b
1111 | Infinities or NaNs
1112 fp_nsf_huge:
1113 subq.l #4,%a0
1114 printf PNORM,"%p(",1,%a0
1115 printx PNORM,%a0@
1116 printf PNORM,")\n"
1117 rts
1119 | conv_ext2int (macro):
1120 | Generates a subroutine that converts an extended value to an
1121 | integer of a given size, again, with the appropriate type of
1122 | rounding.
1124 | Macro arguments:
1125 | s: size, as given in an assembly instruction.
1126 | b: number of bits in that size.
1128 | Subroutine arguments:
1129 | %a0: source (struct fp_ext *)
1131 | Returns the integer in %d0 (like it should)
1133 .macro conv_ext2int s,b
1134 .set inf,(1<<(\b-1))-1 | i.e. MAXINT
1135 printf PCONV,"e2i%d: %p(",2,#\b,%a0
1136 printx PCONV,%a0@
1137 printf PCONV,") "
1138 addq.l #2,%a0
1139 move.w (%a0)+,%d2 | exponent
1140 jeq fp_e2i_zero\b | zero / denorm (== 0, here)
1141 cmp.w #0x7fff,%d2
1142 jeq fp_e2i_huge\b | Inf / NaN
1143 sub.w #0x3ffe,%d2
1144 jcs fp_e2i_small\b
1145 cmp.w #\b,%d2
1146 jhi fp_e2i_large\b
1147 move.l (%a0),%d0
1148 move.l %d0,%d1
1149 lsl.l %d2,%d1
1150 jne fp_e2i_round\b
1151 tst.l (4,%a0)
1152 jne fp_e2i_round\b
1153 neg.w %d2
1154 add.w #32,%d2
1155 lsr.l %d2,%d0
1156 9: tst.w (-4,%a0)
1157 jne 1f
1158 tst.\s %d0
1159 jmi fp_e2i_large\b
1160 printf PCONV,"-> %p\n",1,%d0
1161 rts
1162 1: neg.\s %d0
1163 jeq 1f
1164 jpl fp_e2i_large\b
1165 1: printf PCONV,"-> %p\n",1,%d0
1166 rts
1167 fp_e2i_round\b:
1168 fp_set_sr FPSR_EXC_INEX2 | INEX2 bit
1169 neg.w %d2
1170 add.w #32,%d2
1171 .if \b>16
1172 jeq 5f
1173 .endif
1174 lsr.l %d2,%d0
1175 move.w (FPD_RND,FPDATA),%d2 | rounding mode
1176 jne 2f | %d2 == 0, round to nearest
1177 tst.l %d1 | test guard bit
1178 jpl 9b | zero is closer
1179 btst %d2,%d0 | test lsb bit (%d2 still 0)
1180 jne fp_e2i_doroundup\b
1181 lsl.l #1,%d1 | check low bits
1182 jne fp_e2i_doroundup\b
1183 tst.l (4,%a0)
1184 jeq 9b
1185 fp_e2i_doroundup\b:
1186 addq.l #1,%d0
1187 jra 9b
1188 | check nondefault rounding modes
1189 2: subq.w #2,%d2
1190 jcs 9b | %d2 < 2, round to zero
1191 jhi 3f | %d2 > 2, round to +infinity
1192 tst.w (-4,%a0) | to -inf
1193 jne fp_e2i_doroundup\b | negative, round to infinity
1194 jra 9b | positive, round to zero
1195 3: tst.w (-4,%a0) | to +inf
1196 jeq fp_e2i_doroundup\b | positive, round to infinity
1197 jra 9b | negative, round to zero
1198 | we are only want -2**127 get correctly rounded here,
1199 | since the guard bit is in the lower lword.
1200 | everything else ends up anyway as overflow.
1201 .if \b>16
1202 5: move.w (FPD_RND,FPDATA),%d2 | rounding mode
1203 jne 2b | %d2 == 0, round to nearest
1204 move.l (4,%a0),%d1 | test guard bit
1205 jpl 9b | zero is closer
1206 lsl.l #1,%d1 | check low bits
1207 jne fp_e2i_doroundup\b
1208 jra 9b
1209 .endif
1210 fp_e2i_zero\b:
1211 clr.l %d0
1212 tst.l (%a0)+
1213 jne 1f
1214 tst.l (%a0)
1215 jeq 3f
1216 1: subq.l #4,%a0
1217 fp_clr_sr FPSR_EXC_UNFL | fp_normalize_ext has set this bit
1218 fp_e2i_small\b:
1219 fp_set_sr FPSR_EXC_INEX2
1220 clr.l %d0
1221 move.w (FPD_RND,FPDATA),%d2 | rounding mode
1222 subq.w #2,%d2
1223 jcs 3f | %d2 < 2, round to nearest/zero
1224 jhi 2f | %d2 > 2, round to +infinity
1225 tst.w (-4,%a0) | to -inf
1226 jeq 3f
1227 subq.\s #1,%d0
1228 jra 3f
1229 2: tst.w (-4,%a0) | to +inf
1230 jne 3f
1231 addq.\s #1,%d0
1232 3: printf PCONV,"-> %p\n",1,%d0
1233 rts
1234 fp_e2i_large\b:
1235 fp_set_sr FPSR_EXC_OPERR
1236 move.\s #inf,%d0
1237 tst.w (-4,%a0)
1238 jeq 1f
1239 addq.\s #1,%d0
1240 1: printf PCONV,"-> %p\n",1,%d0
1241 rts
1242 fp_e2i_huge\b:
1243 move.\s (%a0),%d0
1244 tst.l (%a0)
1245 jne 1f
1246 tst.l (%a0)
1247 jeq fp_e2i_large\b
1248 | fp_normalize_ext has set this bit already
1249 | and made the number nonsignaling
1250 1: fp_tst_sr FPSR_EXC_SNAN
1251 jne 1f
1252 fp_set_sr FPSR_EXC_OPERR
1253 1: printf PCONV,"-> %p\n",1,%d0
1254 rts
1255 .endm
1257 fp_conv_ext2long:
1258 conv_ext2int l,32
1260 fp_conv_ext2short:
1261 conv_ext2int w,16
1263 fp_conv_ext2byte:
1264 conv_ext2int b,8
1266 fp_conv_ext2double:
1267 jsr fp_normalize_double
1268 printf PCONV,"e2d: %p(",1,%a0
1269 printx PCONV,%a0@
1270 printf PCONV,"), "
1271 move.l (%a0)+,%d2
1272 cmp.w #0x7fff,%d2
1273 jne 1f
1274 move.w #0x7ff,%d2
1275 move.l (%a0)+,%d0
1276 jra 2f
1277 1: sub.w #0x3fff-0x3ff,%d2
1278 move.l (%a0)+,%d0
1279 jmi 2f
1280 clr.w %d2
1281 2: lsl.w #5,%d2
1282 lsl.l #7,%d2
1283 lsl.l #8,%d2
1284 move.l %d0,%d1
1285 lsl.l #1,%d0
1286 lsr.l #4,%d0
1287 lsr.l #8,%d0
1288 or.l %d2,%d0
1289 putuser.l %d0,(%a1)+,fp_err_ua2,%a1
1290 moveq #21,%d0
1291 lsl.l %d0,%d1
1292 move.l (%a0),%d0
1293 lsr.l #4,%d0
1294 lsr.l #7,%d0
1295 or.l %d1,%d0
1296 putuser.l %d0,(%a1),fp_err_ua2,%a1
1297 #ifdef FPU_EMU_DEBUG
1298 getuser.l %a1@(-4),%d0,fp_err_ua2,%a1
1299 getuser.l %a1@(0),%d1,fp_err_ua2,%a1
1300 printf PCONV,"%p(%08x%08x)\n",3,%a1,%d0,%d1
1301 #endif
1302 rts
1304 fp_conv_ext2single:
1305 jsr fp_normalize_single
1306 printf PCONV,"e2s: %p(",1,%a0
1307 printx PCONV,%a0@
1308 printf PCONV,"), "
1309 move.l (%a0)+,%d1
1310 cmp.w #0x7fff,%d1
1311 jne 1f
1312 move.w #0xff,%d1
1313 move.l (%a0)+,%d0
1314 jra 2f
1315 1: sub.w #0x3fff-0x7f,%d1
1316 move.l (%a0)+,%d0
1317 jmi 2f
1318 clr.w %d1
1319 2: lsl.w #8,%d1
1320 lsl.l #7,%d1
1321 lsl.l #8,%d1
1322 bclr #31,%d0
1323 lsr.l #8,%d0
1324 or.l %d1,%d0
1325 printf PCONV,"%08x\n",1,%d0
1326 rts
1328 | special return addresses for instr that
1329 | encode the rounding precision in the opcode
1330 | (e.g. fsmove,fdmove)
1332 fp_finalrounding_single:
1333 addq.l #8,%sp
1334 jsr fp_normalize_ext
1335 jsr fp_normalize_single
1336 jra fp_finaltest
1338 fp_finalrounding_single_fast:
1339 addq.l #8,%sp
1340 jsr fp_normalize_ext
1341 jsr fp_normalize_single_fast
1342 jra fp_finaltest
1344 fp_finalrounding_double:
1345 addq.l #8,%sp
1346 jsr fp_normalize_ext
1347 jsr fp_normalize_double
1348 jra fp_finaltest
1350 | fp_finaltest:
1351 | set the emulated status register based on the outcome of an
1352 | emulated instruction.
1354 fp_finalrounding:
1355 addq.l #8,%sp
1356 | printf ,"f: %p\n",1,%a0
1357 jsr fp_normalize_ext
1358 move.w (FPD_PREC,FPDATA),%d0
1359 subq.w #1,%d0
1360 jcs fp_finaltest
1361 jne 1f
1362 jsr fp_normalize_single
1363 jra 2f
1364 1: jsr fp_normalize_double
1365 2:| printf ,"f: %p\n",1,%a0
1366 fp_finaltest:
1367 | First, we do some of the obvious tests for the exception
1368 | status byte and condition code bytes of fp_sr here, so that
1369 | they do not have to be handled individually by every
1370 | emulated instruction.
1371 clr.l %d0
1372 addq.l #1,%a0
1373 tst.b (%a0)+ | sign
1374 jeq 1f
1375 bset #FPSR_CC_NEG-24,%d0 | N bit
1376 1: cmp.w #0x7fff,(%a0)+ | exponent
1377 jeq 2f
1378 | test for zero
1379 moveq #FPSR_CC_Z-24,%d1
1380 tst.l (%a0)+
1381 jne 9f
1382 tst.l (%a0)
1383 jne 9f
1384 jra 8f
1385 | infinitiv and NAN
1386 2: moveq #FPSR_CC_NAN-24,%d1
1387 move.l (%a0)+,%d2
1388 lsl.l #1,%d2 | ignore high bit
1389 jne 8f
1390 tst.l (%a0)
1391 jne 8f
1392 moveq #FPSR_CC_INF-24,%d1
1393 8: bset %d1,%d0
1394 9: move.b %d0,(FPD_FPSR+0,FPDATA) | set condition test result
1395 | move instructions enter here
1396 | Here, we test things in the exception status byte, and set
1397 | other things in the accrued exception byte accordingly.
1398 | Emulated instructions can set various things in the former,
1399 | as defined in fp_emu.h.
1400 fp_final:
1401 move.l (FPD_FPSR,FPDATA),%d0
1402 #if 0
1403 btst #FPSR_EXC_SNAN,%d0 | EXC_SNAN
1404 jne 1f
1405 btst #FPSR_EXC_OPERR,%d0 | EXC_OPERR
1406 jeq 2f
1407 1: bset #FPSR_AEXC_IOP,%d0 | set IOP bit
1408 2: btst #FPSR_EXC_OVFL,%d0 | EXC_OVFL
1409 jeq 1f
1410 bset #FPSR_AEXC_OVFL,%d0 | set OVFL bit
1411 1: btst #FPSR_EXC_UNFL,%d0 | EXC_UNFL
1412 jeq 1f
1413 btst #FPSR_EXC_INEX2,%d0 | EXC_INEX2
1414 jeq 1f
1415 bset #FPSR_AEXC_UNFL,%d0 | set UNFL bit
1416 1: btst #FPSR_EXC_DZ,%d0 | EXC_INEX1
1417 jeq 1f
1418 bset #FPSR_AEXC_DZ,%d0 | set DZ bit
1419 1: btst #FPSR_EXC_OVFL,%d0 | EXC_OVFL
1420 jne 1f
1421 btst #FPSR_EXC_INEX2,%d0 | EXC_INEX2
1422 jne 1f
1423 btst #FPSR_EXC_INEX1,%d0 | EXC_INEX1
1424 jeq 2f
1425 1: bset #FPSR_AEXC_INEX,%d0 | set INEX bit
1426 2: move.l %d0,(FPD_FPSR,FPDATA)
1427 #else
1428 | same as above, greatly optimized, but untested (yet)
1429 move.l %d0,%d2
1430 lsr.l #5,%d0
1431 move.l %d0,%d1
1432 lsr.l #4,%d1
1433 or.l %d0,%d1
1434 and.b #0x08,%d1
1435 move.l %d2,%d0
1436 lsr.l #6,%d0
1437 or.l %d1,%d0
1438 move.l %d2,%d1
1439 lsr.l #4,%d1
1440 or.b #0xdf,%d1
1441 and.b %d1,%d0
1442 move.l %d2,%d1
1443 lsr.l #7,%d1
1444 and.b #0x80,%d1
1445 or.b %d1,%d0
1446 and.b #0xf8,%d0
1447 or.b %d0,%d2
1448 move.l %d2,(FPD_FPSR,FPDATA)
1449 #endif
1450 move.b (FPD_FPSR+2,FPDATA),%d0
1451 and.b (FPD_FPCR+2,FPDATA),%d0
1452 jeq 1f
1453 printf ,"send signal!!!\n"
1454 1: jra fp_end