| blob | 5441ec8a7aca9f45ccb6a58ea555a3371e05487a |
1 * $NetBSD: res_func.sa,v 1.5 2001/09/16 16:34:32 wiz Exp $
3 * MOTOROLA MICROPROCESSOR & MEMORY TECHNOLOGY GROUP
4 * M68000 Hi-Performance Microprocessor Division
5 * M68040 Software Package
6 *
7 * M68040 Software Package Copyright (c) 1993, 1994 Motorola Inc.
8 * All rights reserved.
9 *
10 * THE SOFTWARE is provided on an "AS IS" basis and without warranty.
11 * To the maximum extent permitted by applicable law,
12 * MOTOROLA DISCLAIMS ALL WARRANTIES WHETHER EXPRESS OR IMPLIED,
13 * INCLUDING IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A
14 * PARTICULAR PURPOSE and any warranty against infringement with
15 * regard to the SOFTWARE (INCLUDING ANY MODIFIED VERSIONS THEREOF)
16 * and any accompanying written materials.
17 *
18 * To the maximum extent permitted by applicable law,
19 * IN NO EVENT SHALL MOTOROLA BE LIABLE FOR ANY DAMAGES WHATSOEVER
20 * (INCLUDING WITHOUT LIMITATION, DAMAGES FOR LOSS OF BUSINESS
21 * PROFITS, BUSINESS INTERRUPTION, LOSS OF BUSINESS INFORMATION, OR
22 * OTHER PECUNIARY LOSS) ARISING OF THE USE OR INABILITY TO USE THE
23 * SOFTWARE. Motorola assumes no responsibility for the maintenance
24 * and support of the SOFTWARE.
25 *
26 * You are hereby granted a copyright license to use, modify, and
27 * distribute the SOFTWARE so long as this entire notice is retained
28 * without alteration in any modified and/or redistributed versions,
29 * and that such modified versions are clearly identified as such.
30 * No licenses are granted by implication, estoppel or otherwise
31 * under any patents or trademarks of Motorola, Inc.
33 *
34 * res_func.sa 3.9 7/29/91
35 *
36 * Normalizes denormalized numbers if necessary and updates the
37 * stack frame. The function is then restored back into the
38 * machine and the 040 completes the operation. This routine
39 * is only used by the unsupported data type/format handler.
40 * (Exception vector 55).
41 *
42 * For packed move out (fmove.p fpm,<ea>) the operation is
43 * completed here; data is packed and moved to user memory.
44 * The stack is restored to the 040 only in the case of a
45 * reportable exception in the conversion.
46 *
48 RES_FUNC IDNT 2,1 Motorola 040 Floating Point Software Package
50 section 8
52 include fpsp.h
54 sp_bnds: dc.w $3f81,$407e
55 dc.w $3f6a,$0000
56 dp_bnds: dc.w $3c01,$43fe
57 dc.w $3bcd,$0000
59 xref mem_write
60 xref bindec
61 xref get_fline
62 xref round
63 xref denorm
64 xref dest_ext
65 xref dest_dbl
66 xref dest_sgl
67 xref unf_sub
68 xref nrm_set
69 xref dnrm_lp
70 xref ovf_res
71 xref reg_dest
72 xref t_ovfl
73 xref t_unfl
75 xdef res_func
76 xdef p_move
78 res_func:
79 clr.b DNRM_FLG(a6)
80 clr.b RES_FLG(a6)
81 clr.b CU_ONLY(a6)
82 tst.b DY_MO_FLG(a6)
83 beq.b monadic
84 dyadic:
85 btst.b #7,DTAG(a6) ;if dop = norm=000, zero=001,
86 * ;inf=010 or nan=011
87 beq.b monadic ;then branch
88 * ;else denorm
89 * HANDLE DESTINATION DENORM HERE
90 * ;set dtag to norm
91 * ;write the tag & fpte15 to the fstack
92 lea.l FPTEMP(a6),a0
94 bclr.b #sign_bit,LOCAL_EX(a0)
95 sne LOCAL_SGN(a0)
97 bsr nrm_set ;normalize number (exp will go negative)
98 bclr.b #sign_bit,LOCAL_EX(a0) ;get rid of false sign
99 bfclr LOCAL_SGN(a0){0:8} ;change back to IEEE ext format
100 beq.b dpos
101 bset.b #sign_bit,LOCAL_EX(a0)
102 dpos:
103 bfclr DTAG(a6){0:4} ;set tag to normalized, FPTE15 = 0
104 bset.b #4,DTAG(a6) ;set FPTE15
105 or.b #$0f,DNRM_FLG(a6)
106 monadic:
107 lea.l ETEMP(a6),a0
108 btst.b #direction_bit,CMDREG1B(a6) ;check direction
109 bne.w opclass3 ;it is a mv out
110 *
111 * At this point, only oplcass 0 and 2 possible
112 *
113 btst.b #7,STAG(a6) ;if sop = norm=000, zero=001,
114 * ;inf=010 or nan=011
115 bne.w mon_dnrm ;else denorm
116 tst.b DY_MO_FLG(a6) ;all cases of dyadic instructions would
117 bne.w normal ;require normalization of denorm
119 * At this point:
120 * monadic instructions: fabs = $18 fneg = $1a ftst = $3a
121 * fmove = $00 fsmove = $40 fdmove = $44
122 * fsqrt = $05* fssqrt = $41 fdsqrt = $45
123 * (*fsqrt reencoded to $05)
124 *
125 move.w CMDREG1B(a6),d0 ;get command register
126 andi.l #$7f,d0 ;strip to only command word
127 *
128 * At this point, fabs, fneg, fsmove, fdmove, ftst, fsqrt, fssqrt, and
129 * fdsqrt are possible.
130 * For cases fabs, fneg, fsmove, and fdmove goto spos (do not normalize)
131 * For cases fsqrt, fssqrt, and fdsqrt goto nrm_src (do normalize)
132 *
133 btst.l #0,d0
134 bne.w normal ;weed out fsqrt instructions
135 *
136 * cu_norm handles fmove in instructions with normalized inputs.
137 * The routine round is used to correctly round the input for the
138 * destination precision and mode.
139 *
140 cu_norm:
141 st CU_ONLY(a6) ;set cu-only inst flag
142 move.w CMDREG1B(a6),d0
143 andi.b #$3b,d0 ;isolate bits to select inst
144 tst.b d0
145 beq.l cu_nmove ;if zero, it is an fmove
146 cmpi.b #$18,d0
147 beq.l cu_nabs ;if $18, it is fabs
148 cmpi.b #$1a,d0
149 beq.l cu_nneg ;if $1a, it is fneg
150 *
151 * Inst is ftst. Check the source operand and set the cc's accordingly.
152 * No write is done, so simply rts.
153 *
154 cu_ntst:
155 move.w LOCAL_EX(a0),d0
156 bclr.l #15,d0
157 sne LOCAL_SGN(a0)
158 beq.b cu_ntpo
159 or.l #neg_mask,USER_FPSR(a6) ;set N
160 cu_ntpo:
161 cmpi.w #$7fff,d0 ;test for inf/nan
162 bne.b cu_ntcz
163 tst.l LOCAL_HI(a0)
164 bne.b cu_ntn
165 tst.l LOCAL_LO(a0)
166 bne.b cu_ntn
167 or.l #inf_mask,USER_FPSR(a6)
168 rts
169 cu_ntn:
170 or.l #nan_mask,USER_FPSR(a6)
171 move.l ETEMP_EX(a6),FPTEMP_EX(a6) ;set up fptemp sign for
172 * ;snan handler
174 rts
175 cu_ntcz:
176 tst.l LOCAL_HI(a0)
177 bne.l cu_ntsx
178 tst.l LOCAL_LO(a0)
179 bne.l cu_ntsx
180 or.l #z_mask,USER_FPSR(a6)
181 cu_ntsx:
182 rts
183 *
184 * Inst is fabs. Execute the absolute value function on the input.
185 * Branch to the fmove code. If the operand is NaN, do nothing.
186 *
187 cu_nabs:
188 move.b STAG(a6),d0
189 btst.l #5,d0 ;test for NaN or zero
190 bne wr_etemp ;if either, simply write it
191 bclr.b #7,LOCAL_EX(a0) ;do abs
192 bra.b cu_nmove ;fmove code will finish
193 *
194 * Inst is fneg. Execute the negate value function on the input.
195 * Fall though to the fmove code. If the operand is NaN, do nothing.
196 *
197 cu_nneg:
198 move.b STAG(a6),d0
199 btst.l #5,d0 ;test for NaN or zero
200 bne wr_etemp ;if either, simply write it
201 bchg.b #7,LOCAL_EX(a0) ;do neg
202 *
203 * Inst is fmove. This code also handles all result writes.
204 * If bit 2 is set, round is forced to double. If it is clear,
205 * and bit 6 is set, round is forced to single. If both are clear,
206 * the round precision is found in the fpcr. If the rounding precision
207 * is double or single, round the result before the write.
208 *
209 cu_nmove:
210 move.b STAG(a6),d0
211 andi.b #$e0,d0 ;isolate stag bits
212 bne wr_etemp ;if not norm, simply write it
213 btst.b #2,CMDREG1B+1(a6) ;check for rd
214 bne cu_nmrd
215 btst.b #6,CMDREG1B+1(a6) ;check for rs
216 bne cu_nmrs
217 *
218 * The move or operation is not with forced precision. Test for
219 * nan or inf as the input; if so, simply write it to FPn. Use the
220 * FPCR_MODE byte to get rounding on norms and zeros.
221 *
222 cu_nmnr:
223 bfextu FPCR_MODE(a6){0:2},d0
224 tst.b d0 ;check for extended
225 beq cu_wrexn ;if so, just write result
226 cmpi.b #1,d0 ;check for single
227 beq cu_nmrs ;fall through to double
228 *
229 * The move is fdmove or round precision is double.
230 *
231 cu_nmrd:
232 move.l #2,d0 ;set up the size for denorm
233 move.w LOCAL_EX(a0),d1 ;compare exponent to double threshold
234 and.w #$7fff,d1
235 cmp.w #$3c01,d1
236 bls cu_nunfl
237 bfextu FPCR_MODE(a6){2:2},d1 ;get rmode
238 or.l #$00020000,d1 ;or in rprec (double)
239 clr.l d0 ;clear g,r,s for round
240 bclr.b #sign_bit,LOCAL_EX(a0) ;convert to internal format
241 sne LOCAL_SGN(a0)
242 bsr.l round
243 bfclr LOCAL_SGN(a0){0:8}
244 beq.b cu_nmrdc
245 bset.b #sign_bit,LOCAL_EX(a0)
246 cu_nmrdc:
247 move.w LOCAL_EX(a0),d1 ;check for overflow
248 and.w #$7fff,d1
249 cmp.w #$43ff,d1
250 bge cu_novfl ;take care of overflow case
251 bra.w cu_wrexn
252 *
253 * The move is fsmove or round precision is single.
254 *
255 cu_nmrs:
256 move.l #1,d0
257 move.w LOCAL_EX(a0),d1
258 and.w #$7fff,d1
259 cmp.w #$3f81,d1
260 bls cu_nunfl
261 bfextu FPCR_MODE(a6){2:2},d1
262 or.l #$00010000,d1
263 clr.l d0
264 bclr.b #sign_bit,LOCAL_EX(a0)
265 sne LOCAL_SGN(a0)
266 bsr.l round
267 bfclr LOCAL_SGN(a0){0:8}
268 beq.b cu_nmrsc
269 bset.b #sign_bit,LOCAL_EX(a0)
270 cu_nmrsc:
271 move.w LOCAL_EX(a0),d1
272 and.w #$7FFF,d1
273 cmp.w #$407f,d1
274 blt cu_wrexn
275 *
276 * The operand is above precision boundaries. Use t_ovfl to
277 * generate the correct value.
278 *
279 cu_novfl:
280 bsr t_ovfl
281 bra cu_wrexn
282 *
283 * The operand is below precision boundaries. Use denorm to
284 * generate the correct value.
285 *
286 cu_nunfl:
287 bclr.b #sign_bit,LOCAL_EX(a0)
288 sne LOCAL_SGN(a0)
289 bsr denorm
290 bfclr LOCAL_SGN(a0){0:8} ;change back to IEEE ext format
291 beq.b cu_nucont
292 bset.b #sign_bit,LOCAL_EX(a0)
293 cu_nucont:
294 bfextu FPCR_MODE(a6){2:2},d1
295 btst.b #2,CMDREG1B+1(a6) ;check for rd
296 bne inst_d
297 btst.b #6,CMDREG1B+1(a6) ;check for rs
298 bne inst_s
299 swap d1
300 move.b FPCR_MODE(a6),d1
301 lsr.b #6,d1
302 swap d1
303 bra inst_sd
304 inst_d:
305 or.l #$00020000,d1
306 bra inst_sd
307 inst_s:
308 or.l #$00010000,d1
309 inst_sd:
310 bclr.b #sign_bit,LOCAL_EX(a0)
311 sne LOCAL_SGN(a0)
312 bsr.l round
313 bfclr LOCAL_SGN(a0){0:8}
314 beq.b cu_nuflp
315 bset.b #sign_bit,LOCAL_EX(a0)
316 cu_nuflp:
317 btst.b #inex2_bit,FPSR_EXCEPT(a6)
318 beq.b cu_nuninx
319 or.l #aunfl_mask,USER_FPSR(a6) ;if the round was inex, set AUNFL
320 cu_nuninx:
321 tst.l LOCAL_HI(a0) ;test for zero
322 bne.b cu_nunzro
323 tst.l LOCAL_LO(a0)
324 bne.b cu_nunzro
325 *
326 * The mantissa is zero from the denorm loop. Check sign and rmode
327 * to see if rounding should have occurred which would leave the lsb.
328 *
329 move.l USER_FPCR(a6),d0
330 andi.l #$30,d0 ;isolate rmode
331 cmpi.l #$20,d0
332 blt.b cu_nzro
333 bne.b cu_nrp
334 cu_nrm:
335 tst.w LOCAL_EX(a0) ;if positive, set lsb
336 bge.b cu_nzro
337 btst.b #7,FPCR_MODE(a6) ;check for double
338 beq.b cu_nincs
339 bra.b cu_nincd
340 cu_nrp:
341 tst.w LOCAL_EX(a0) ;if positive, set lsb
342 blt.b cu_nzro
343 btst.b #7,FPCR_MODE(a6) ;check for double
344 beq.b cu_nincs
345 cu_nincd:
346 or.l #$800,LOCAL_LO(a0) ;inc for double
347 bra cu_nunzro
348 cu_nincs:
349 or.l #$100,LOCAL_HI(a0) ;inc for single
350 bra cu_nunzro
351 cu_nzro:
352 or.l #z_mask,USER_FPSR(a6)
353 move.b STAG(a6),d0
354 andi.b #$e0,d0
355 cmpi.b #$40,d0 ;check if input was tagged zero
356 beq.b cu_numv
357 cu_nunzro:
358 or.l #unfl_mask,USER_FPSR(a6) ;set unfl
359 cu_numv:
360 move.l (a0),ETEMP(a6)
361 move.l 4(a0),ETEMP_HI(a6)
362 move.l 8(a0),ETEMP_LO(a6)
363 *
364 * Write the result to memory, setting the fpsr cc bits. NaN and Inf
365 * bypass cu_wrexn.
366 *
367 cu_wrexn:
368 tst.w LOCAL_EX(a0) ;test for zero
369 beq.b cu_wrzero
370 cmp.w #$8000,LOCAL_EX(a0) ;test for zero
371 bne.b cu_wreon
372 cu_wrzero:
373 or.l #z_mask,USER_FPSR(a6) ;set Z bit
374 cu_wreon:
375 tst.w LOCAL_EX(a0)
376 bpl wr_etemp
377 or.l #neg_mask,USER_FPSR(a6)
378 bra wr_etemp
380 *
381 * HANDLE SOURCE DENORM HERE
382 *
383 * ;clear denorm stag to norm
384 * ;write the new tag & ete15 to the fstack
385 mon_dnrm:
386 *
387 * At this point, check for the cases in which normalizing the
388 * denorm produces incorrect results.
389 *
390 tst.b DY_MO_FLG(a6) ;all cases of dyadic instructions would
391 bne.b nrm_src ;require normalization of denorm
393 * At this point:
394 * monadic instructions: fabs = $18 fneg = $1a ftst = $3a
395 * fmove = $00 fsmove = $40 fdmove = $44
396 * fsqrt = $05* fssqrt = $41 fdsqrt = $45
397 * (*fsqrt reencoded to $05)
398 *
399 move.w CMDREG1B(a6),d0 ;get command register
400 andi.l #$7f,d0 ;strip to only command word
401 *
402 * At this point, fabs, fneg, fsmove, fdmove, ftst, fsqrt, fssqrt, and
403 * fdsqrt are possible.
404 * For cases fabs, fneg, fsmove, and fdmove goto spos (do not normalize)
405 * For cases fsqrt, fssqrt, and fdsqrt goto nrm_src (do normalize)
406 *
407 btst.l #0,d0
408 bne.b nrm_src ;weed out fsqrt instructions
409 st CU_ONLY(a6) ;set cu-only inst flag
410 bra cu_dnrm ;fmove, fabs, fneg, ftst
411 * ;cases go to cu_dnrm
412 nrm_src:
413 bclr.b #sign_bit,LOCAL_EX(a0)
414 sne LOCAL_SGN(a0)
415 bsr nrm_set ;normalize number (exponent will go
416 * ; negative)
417 bclr.b #sign_bit,LOCAL_EX(a0) ;get rid of false sign
419 bfclr LOCAL_SGN(a0){0:8} ;change back to IEEE ext format
420 beq.b spos
421 bset.b #sign_bit,LOCAL_EX(a0)
422 spos:
423 bfclr STAG(a6){0:4} ;set tag to normalized, FPTE15 = 0
424 bset.b #4,STAG(a6) ;set ETE15
425 or.b #$f0,DNRM_FLG(a6)
426 normal:
427 tst.b DNRM_FLG(a6) ;check if any of the ops were denorms
428 bne ck_wrap ;if so, check if it is a potential
429 * ;wrap-around case
430 fix_stk:
431 move.b #$fe,CU_SAVEPC(a6)
432 bclr.b #E1,E_BYTE(a6)
434 clr.w NMNEXC(a6)
436 st.b RES_FLG(a6) ;indicate that a restore is needed
437 rts
439 *
440 * cu_dnrm handles all cu-only instructions (fmove, fabs, fneg, and
441 * ftst) completly in software without an frestore to the 040.
442 *
443 cu_dnrm:
444 st.b CU_ONLY(a6)
445 move.w CMDREG1B(a6),d0
446 andi.b #$3b,d0 ;isolate bits to select inst
447 tst.b d0
448 beq.l cu_dmove ;if zero, it is an fmove
449 cmpi.b #$18,d0
450 beq.l cu_dabs ;if $18, it is fabs
451 cmpi.b #$1a,d0
452 beq.l cu_dneg ;if $1a, it is fneg
453 *
454 * Inst is ftst. Check the source operand and set the cc's accordingly.
455 * No write is done, so simply rts.
456 *
457 cu_dtst:
458 move.w LOCAL_EX(a0),d0
459 bclr.l #15,d0
460 sne LOCAL_SGN(a0)
461 beq.b cu_dtpo
462 or.l #neg_mask,USER_FPSR(a6) ;set N
463 cu_dtpo:
464 cmpi.w #$7fff,d0 ;test for inf/nan
465 bne.b cu_dtcz
466 tst.l LOCAL_HI(a0)
467 bne.b cu_dtn
468 tst.l LOCAL_LO(a0)
469 bne.b cu_dtn
470 or.l #inf_mask,USER_FPSR(a6)
471 rts
472 cu_dtn:
473 or.l #nan_mask,USER_FPSR(a6)
474 move.l ETEMP_EX(a6),FPTEMP_EX(a6) ;set up fptemp sign for
475 * ;snan handler
476 rts
477 cu_dtcz:
478 tst.l LOCAL_HI(a0)
479 bne.l cu_dtsx
480 tst.l LOCAL_LO(a0)
481 bne.l cu_dtsx
482 or.l #z_mask,USER_FPSR(a6)
483 cu_dtsx:
484 rts
485 *
486 * Inst is fabs. Execute the absolute value function on the input.
487 * Branch to the fmove code.
488 *
489 cu_dabs:
490 bclr.b #7,LOCAL_EX(a0) ;do abs
491 bra.b cu_dmove ;fmove code will finish
492 *
493 * Inst is fneg. Execute the negate value function on the input.
494 * Fall though to the fmove code.
495 *
496 cu_dneg:
497 bchg.b #7,LOCAL_EX(a0) ;do neg
498 *
499 * Inst is fmove. This code also handles all result writes.
500 * If bit 2 is set, round is forced to double. If it is clear,
501 * and bit 6 is set, round is forced to single. If both are clear,
502 * the round precision is found in the fpcr. If the rounding precision
503 * is double or single, the result is zero, and the mode is checked
504 * to determine if the lsb of the result should be set.
505 *
506 cu_dmove:
507 btst.b #2,CMDREG1B+1(a6) ;check for rd
508 bne cu_dmrd
509 btst.b #6,CMDREG1B+1(a6) ;check for rs
510 bne cu_dmrs
511 *
512 * The move or operation is not with forced precision. Use the
513 * FPCR_MODE byte to get rounding.
514 *
515 cu_dmnr:
516 bfextu FPCR_MODE(a6){0:2},d0
517 tst.b d0 ;check for extended
518 beq cu_wrexd ;if so, just write result
519 cmpi.b #1,d0 ;check for single
520 beq cu_dmrs ;fall through to double
521 *
522 * The move is fdmove or round precision is double. Result is zero.
523 * Check rmode for rp or rm and set lsb accordingly.
524 *
525 cu_dmrd:
526 bfextu FPCR_MODE(a6){2:2},d1 ;get rmode
527 tst.w LOCAL_EX(a0) ;check sign
528 blt.b cu_dmdn
529 cmpi.b #3,d1 ;check for rp
530 bne cu_dpd ;load double pos zero
531 bra cu_dpdr ;load double pos zero w/lsb
532 cu_dmdn:
533 cmpi.b #2,d1 ;check for rm
534 bne cu_dnd ;load double neg zero
535 bra cu_dndr ;load double neg zero w/lsb
536 *
537 * The move is fsmove or round precision is single. Result is zero.
538 * Check for rp or rm and set lsb accordingly.
539 *
540 cu_dmrs:
541 bfextu FPCR_MODE(a6){2:2},d1 ;get rmode
542 tst.w LOCAL_EX(a0) ;check sign
543 blt.b cu_dmsn
544 cmpi.b #3,d1 ;check for rp
545 bne cu_spd ;load single pos zero
546 bra cu_spdr ;load single pos zero w/lsb
547 cu_dmsn:
548 cmpi.b #2,d1 ;check for rm
549 bne cu_snd ;load single neg zero
550 bra cu_sndr ;load single neg zero w/lsb
551 *
552 * The precision is extended, so the result in etemp is correct.
553 * Simply set unfl (not inex2 or aunfl) and write the result to
554 * the correct fp register.
555 cu_wrexd:
556 or.l #unfl_mask,USER_FPSR(a6)
557 tst.w LOCAL_EX(a0)
558 beq wr_etemp
559 or.l #neg_mask,USER_FPSR(a6)
560 bra wr_etemp
561 *
562 * These routines write +/- zero in double format. The routines
563 * cu_dpdr and cu_dndr set the double lsb.
564 *
565 cu_dpd:
566 move.l #$3c010000,LOCAL_EX(a0) ;force pos double zero
567 clr.l LOCAL_HI(a0)
568 clr.l LOCAL_LO(a0)
569 or.l #z_mask,USER_FPSR(a6)
570 or.l #unfinx_mask,USER_FPSR(a6)
571 bra wr_etemp
572 cu_dpdr:
573 move.l #$3c010000,LOCAL_EX(a0) ;force pos double zero
574 clr.l LOCAL_HI(a0)
575 move.l #$800,LOCAL_LO(a0) ;with lsb set
576 or.l #unfinx_mask,USER_FPSR(a6)
577 bra wr_etemp
578 cu_dnd:
579 move.l #$bc010000,LOCAL_EX(a0) ;force pos double zero
580 clr.l LOCAL_HI(a0)
581 clr.l LOCAL_LO(a0)
582 or.l #z_mask,USER_FPSR(a6)
583 or.l #neg_mask,USER_FPSR(a6)
584 or.l #unfinx_mask,USER_FPSR(a6)
585 bra wr_etemp
586 cu_dndr:
587 move.l #$bc010000,LOCAL_EX(a0) ;force pos double zero
588 clr.l LOCAL_HI(a0)
589 move.l #$800,LOCAL_LO(a0) ;with lsb set
590 or.l #neg_mask,USER_FPSR(a6)
591 or.l #unfinx_mask,USER_FPSR(a6)
592 bra wr_etemp
593 *
594 * These routines write +/- zero in single format. The routines
595 * cu_dpdr and cu_dndr set the single lsb.
596 *
597 cu_spd:
598 move.l #$3f810000,LOCAL_EX(a0) ;force pos single zero
599 clr.l LOCAL_HI(a0)
600 clr.l LOCAL_LO(a0)
601 or.l #z_mask,USER_FPSR(a6)
602 or.l #unfinx_mask,USER_FPSR(a6)
603 bra wr_etemp
604 cu_spdr:
605 move.l #$3f810000,LOCAL_EX(a0) ;force pos single zero
606 move.l #$100,LOCAL_HI(a0) ;with lsb set
607 clr.l LOCAL_LO(a0)
608 or.l #unfinx_mask,USER_FPSR(a6)
609 bra wr_etemp
610 cu_snd:
611 move.l #$bf810000,LOCAL_EX(a0) ;force pos single zero
612 clr.l LOCAL_HI(a0)
613 clr.l LOCAL_LO(a0)
614 or.l #z_mask,USER_FPSR(a6)
615 or.l #neg_mask,USER_FPSR(a6)
616 or.l #unfinx_mask,USER_FPSR(a6)
617 bra wr_etemp
618 cu_sndr:
619 move.l #$bf810000,LOCAL_EX(a0) ;force pos single zero
620 move.l #$100,LOCAL_HI(a0) ;with lsb set
621 clr.l LOCAL_LO(a0)
622 or.l #neg_mask,USER_FPSR(a6)
623 or.l #unfinx_mask,USER_FPSR(a6)
624 bra wr_etemp
626 *
627 * This code checks for 16-bit overflow conditions on dyadic
628 * operations which are not restorable into the floating-point
629 * unit and must be completed in software. Basically, this
630 * condition exists with a very large norm and a denorm. One
631 * of the operands must be denormalized to enter this code.
632 *
633 * Flags used:
634 * DY_MO_FLG contains 0 for monadic op, $ff for dyadic
635 * DNRM_FLG contains $00 for neither op denormalized
636 * $0f for the destination op denormalized
637 * $f0 for the source op denormalized
638 * $ff for both ops denormalzed
639 *
640 * The wrap-around condition occurs for add, sub, div, and cmp
641 * when
642 *
643 * abs(dest_exp - src_exp) >= $8000
644 *
645 * and for mul when
646 *
647 * (dest_exp + src_exp) < $0
648 *
649 * we must process the operation here if this case is true.
650 *
651 * The rts following the frcfpn routine is the exit from res_func
652 * for this condition. The restore flag (RES_FLG) is left clear.
653 * No frestore is done unless an exception is to be reported.
654 *
655 * For fadd:
656 * if(sign_of(dest) != sign_of(src))
657 * replace exponent of src with $3fff (keep sign)
658 * use fpu to perform dest+new_src (user's rmode and X)
659 * clr sticky
660 * else
661 * set sticky
662 * call round with user's precision and mode
663 * move result to fpn and wbtemp
664 *
665 * For fsub:
666 * if(sign_of(dest) == sign_of(src))
667 * replace exponent of src with $3fff (keep sign)
668 * use fpu to perform dest+new_src (user's rmode and X)
669 * clr sticky
670 * else
671 * set sticky
672 * call round with user's precision and mode
673 * move result to fpn and wbtemp
674 *
675 * For fdiv/fsgldiv:
676 * if(both operands are denorm)
677 * restore_to_fpu;
678 * if(dest is norm)
679 * force_ovf;
680 * else(dest is denorm)
681 * force_unf:
682 *
683 * For fcmp:
684 * if(dest is norm)
685 * N = sign_of(dest);
686 * else(dest is denorm)
687 * N = sign_of(src);
688 *
689 * For fmul:
690 * if(both operands are denorm)
691 * force_unf;
692 * if((dest_exp + src_exp) < 0)
693 * force_unf:
694 * else
695 * restore_to_fpu;
696 *
697 * local equates:
698 addcode equ $22
699 subcode equ $28
700 mulcode equ $23
701 divcode equ $20
702 cmpcode equ $38
703 ck_wrap:
704 tst.b DY_MO_FLG(a6) ;check for fsqrt
705 beq fix_stk ;if zero, it is fsqrt
706 move.w CMDREG1B(a6),d0
707 andi.w #$3b,d0 ;strip to command bits
708 cmpi.w #addcode,d0
709 beq wrap_add
710 cmpi.w #subcode,d0
711 beq wrap_sub
712 cmpi.w #mulcode,d0
713 beq wrap_mul
714 cmpi.w #cmpcode,d0
715 beq wrap_cmp
716 *
717 * Inst is fdiv.
718 *
719 wrap_div:
720 cmp.b #$ff,DNRM_FLG(a6) ;if both ops denorm,
721 beq fix_stk ;restore to fpu
722 *
723 * One of the ops is denormalized. Test for wrap condition
724 * and force the result.
725 *
726 cmp.b #$0f,DNRM_FLG(a6) ;check for dest denorm
727 bne.b div_srcd
728 div_destd:
729 bsr.l ckinf_ns
730 bne fix_stk
731 bfextu ETEMP_EX(a6){1:15},d0 ;get src exp (always pos)
732 bfexts FPTEMP_EX(a6){1:15},d1 ;get dest exp (always neg)
733 sub.l d1,d0 ;subtract dest from src
734 cmp.l #$7fff,d0
735 blt fix_stk ;if less, not wrap case
736 clr.b WBTEMP_SGN(a6)
737 move.w ETEMP_EX(a6),d0 ;find the sign of the result
738 move.w FPTEMP_EX(a6),d1
739 eor.w d1,d0
740 andi.w #$8000,d0
741 beq force_unf
742 st.b WBTEMP_SGN(a6)
743 bra force_unf
745 ckinf_ns:
746 move.b STAG(a6),d0 ;check source tag for inf or nan
747 bra ck_in_com
748 ckinf_nd:
749 move.b DTAG(a6),d0 ;check destination tag for inf or nan
750 ck_in_com:
751 andi.b #$60,d0 ;isolate tag bits
752 cmp.b #$40,d0 ;is it inf?
753 beq nan_or_inf ;not wrap case
754 cmp.b #$60,d0 ;is it nan?
755 beq nan_or_inf ;yes, not wrap case?
756 cmp.b #$20,d0 ;is it a zero?
757 beq nan_or_inf ;yes
758 clr.l d0
759 rts ;then it is either a zero of norm,
760 * ;check wrap case
761 nan_or_inf:
762 moveq.l #-1,d0
763 rts
767 div_srcd:
768 bsr.l ckinf_nd
769 bne fix_stk
770 bfextu FPTEMP_EX(a6){1:15},d0 ;get dest exp (always pos)
771 bfexts ETEMP_EX(a6){1:15},d1 ;get src exp (always neg)
772 sub.l d1,d0 ;subtract src from dest
773 cmp.l #$8000,d0
774 blt fix_stk ;if less, not wrap case
775 clr.b WBTEMP_SGN(a6)
776 move.w ETEMP_EX(a6),d0 ;find the sign of the result
777 move.w FPTEMP_EX(a6),d1
778 eor.w d1,d0
779 andi.w #$8000,d0
780 beq.b force_ovf
781 st.b WBTEMP_SGN(a6)
782 *
783 * This code handles the case of the instruction resulting in
784 * an overflow condition.
785 *
786 force_ovf:
787 bclr.b #E1,E_BYTE(a6)
788 or.l #ovfl_inx_mask,USER_FPSR(a6)
789 clr.w NMNEXC(a6)
790 lea.l WBTEMP(a6),a0 ;point a0 to memory location
791 move.w CMDREG1B(a6),d0
792 btst.l #6,d0 ;test for forced precision
793 beq.b frcovf_fpcr
794 btst.l #2,d0 ;check for double
795 bne.b frcovf_dbl
796 move.l #$1,d0 ;inst is forced single
797 bra.b frcovf_rnd
798 frcovf_dbl:
799 move.l #$2,d0 ;inst is forced double
800 bra.b frcovf_rnd
801 frcovf_fpcr:
802 bfextu FPCR_MODE(a6){0:2},d0 ;inst not forced - use fpcr prec
803 frcovf_rnd:
805 * The 881/882 does not set inex2 for the following case, so the
806 * line is commented out to be compatible with 881/882
807 * tst.b d0
808 * beq.b frcovf_x
809 * or.l #inex2_mask,USER_FPSR(a6) ;if prec is s or d, set inex2
811 *frcovf_x:
812 bsr.l ovf_res ;get correct result based on
813 * ;round precision/mode. This
814 * ;sets FPSR_CC correctly
815 * ;returns in external format
816 bfclr WBTEMP_SGN(a6){0:8}
817 beq frcfpn
818 bset.b #sign_bit,WBTEMP_EX(a6)
819 bra frcfpn
820 *
821 * Inst is fadd.
822 *
823 wrap_add:
824 cmp.b #$ff,DNRM_FLG(a6) ;if both ops denorm,
825 beq fix_stk ;restore to fpu
826 *
827 * One of the ops is denormalized. Test for wrap condition
828 * and complete the instruction.
829 *
830 cmp.b #$0f,DNRM_FLG(a6) ;check for dest denorm
831 bne.b add_srcd
832 add_destd:
833 bsr.l ckinf_ns
834 bne fix_stk
835 bfextu ETEMP_EX(a6){1:15},d0 ;get src exp (always pos)
836 bfexts FPTEMP_EX(a6){1:15},d1 ;get dest exp (always neg)
837 sub.l d1,d0 ;subtract dest from src
838 cmp.l #$8000,d0
839 blt fix_stk ;if less, not wrap case
840 bra add_wrap
841 add_srcd:
842 bsr.l ckinf_nd
843 bne fix_stk
844 bfextu FPTEMP_EX(a6){1:15},d0 ;get dest exp (always pos)
845 bfexts ETEMP_EX(a6){1:15},d1 ;get src exp (always neg)
846 sub.l d1,d0 ;subtract src from dest
847 cmp.l #$8000,d0
848 blt fix_stk ;if less, not wrap case
849 *
850 * Check the signs of the operands. If they are unlike, the fpu
851 * can be used to add the norm and 1.0 with the sign of the
852 * denorm and it will correctly generate the result in extended
853 * precision. We can then call round with no sticky and the result
854 * will be correct for the user's rounding mode and precision. If
855 * the signs are the same, we call round with the sticky bit set
856 * and the result will be correctfor the user's rounding mode and
857 * precision.
858 *
859 add_wrap:
860 move.w ETEMP_EX(a6),d0
861 move.w FPTEMP_EX(a6),d1
862 eor.w d1,d0
863 andi.w #$8000,d0
864 beq add_same
865 *
866 * The signs are unlike.
867 *
868 cmp.b #$0f,DNRM_FLG(a6) ;is dest the denorm?
869 bne.b add_u_srcd
870 move.w FPTEMP_EX(a6),d0
871 andi.w #$8000,d0
872 or.w #$3fff,d0 ;force the exponent to +/- 1
873 move.w d0,FPTEMP_EX(a6) ;in the denorm
874 move.l USER_FPCR(a6),d0
875 andi.l #$30,d0
876 fmove.l d0,fpcr ;set up users rmode and X
877 fmove.x ETEMP(a6),fp0
878 fadd.x FPTEMP(a6),fp0
879 lea.l WBTEMP(a6),a0 ;point a0 to wbtemp in frame
880 fmove.l fpsr,d1
881 or.l d1,USER_FPSR(a6) ;capture cc's and inex from fadd
882 fmove.x fp0,WBTEMP(a6) ;write result to memory
883 lsr.l #4,d0 ;put rmode in lower 2 bits
884 move.l USER_FPCR(a6),d1
885 andi.l #$c0,d1
886 lsr.l #6,d1 ;put precision in upper word
887 swap d1
888 or.l d0,d1 ;set up for round call
889 clr.l d0 ;force sticky to zero
890 bclr.b #sign_bit,WBTEMP_EX(a6)
891 sne WBTEMP_SGN(a6)
892 bsr.l round ;round result to users rmode & prec
893 bfclr WBTEMP_SGN(a6){0:8} ;convert back to IEEE ext format
894 beq frcfpnr
895 bset.b #sign_bit,WBTEMP_EX(a6)
896 bra frcfpnr
897 add_u_srcd:
898 move.w ETEMP_EX(a6),d0
899 andi.w #$8000,d0
900 or.w #$3fff,d0 ;force the exponent to +/- 1
901 move.w d0,ETEMP_EX(a6) ;in the denorm
902 move.l USER_FPCR(a6),d0
903 andi.l #$30,d0
904 fmove.l d0,fpcr ;set up users rmode and X
905 fmove.x ETEMP(a6),fp0
906 fadd.x FPTEMP(a6),fp0
907 fmove.l fpsr,d1
908 or.l d1,USER_FPSR(a6) ;capture cc's and inex from fadd
909 lea.l WBTEMP(a6),a0 ;point a0 to wbtemp in frame
910 fmove.x fp0,WBTEMP(a6) ;write result to memory
911 lsr.l #4,d0 ;put rmode in lower 2 bits
912 move.l USER_FPCR(a6),d1
913 andi.l #$c0,d1
914 lsr.l #6,d1 ;put precision in upper word
915 swap d1
916 or.l d0,d1 ;set up for round call
917 clr.l d0 ;force sticky to zero
918 bclr.b #sign_bit,WBTEMP_EX(a6)
919 sne WBTEMP_SGN(a6) ;use internal format for round
920 bsr.l round ;round result to users rmode & prec
921 bfclr WBTEMP_SGN(a6){0:8} ;convert back to IEEE ext format
922 beq frcfpnr
923 bset.b #sign_bit,WBTEMP_EX(a6)
924 bra frcfpnr
925 *
926 * Signs are alike:
927 *
928 add_same:
929 cmp.b #$0f,DNRM_FLG(a6) ;is dest the denorm?
930 bne.b add_s_srcd
931 add_s_destd:
932 lea.l ETEMP(a6),a0
933 move.l USER_FPCR(a6),d0
934 andi.l #$30,d0
935 lsr.l #4,d0 ;put rmode in lower 2 bits
936 move.l USER_FPCR(a6),d1
937 andi.l #$c0,d1
938 lsr.l #6,d1 ;put precision in upper word
939 swap d1
940 or.l d0,d1 ;set up for round call
941 move.l #$20000000,d0 ;set sticky for round
942 bclr.b #sign_bit,ETEMP_EX(a6)
943 sne ETEMP_SGN(a6)
944 bsr.l round ;round result to users rmode & prec
945 bfclr ETEMP_SGN(a6){0:8} ;convert back to IEEE ext format
946 beq.b add_s_dclr
947 bset.b #sign_bit,ETEMP_EX(a6)
948 add_s_dclr:
949 lea.l WBTEMP(a6),a0
950 move.l ETEMP(a6),(a0) ;write result to wbtemp
951 move.l ETEMP_HI(a6),4(a0)
952 move.l ETEMP_LO(a6),8(a0)
953 tst.w ETEMP_EX(a6)
954 bgt add_ckovf
955 or.l #neg_mask,USER_FPSR(a6)
956 bra add_ckovf
957 add_s_srcd:
958 lea.l FPTEMP(a6),a0
959 move.l USER_FPCR(a6),d0
960 andi.l #$30,d0
961 lsr.l #4,d0 ;put rmode in lower 2 bits
962 move.l USER_FPCR(a6),d1
963 andi.l #$c0,d1
964 lsr.l #6,d1 ;put precision in upper word
965 swap d1
966 or.l d0,d1 ;set up for round call
967 move.l #$20000000,d0 ;set sticky for round
968 bclr.b #sign_bit,FPTEMP_EX(a6)
969 sne FPTEMP_SGN(a6)
970 bsr.l round ;round result to users rmode & prec
971 bfclr FPTEMP_SGN(a6){0:8} ;convert back to IEEE ext format
972 beq.b add_s_sclr
973 bset.b #sign_bit,FPTEMP_EX(a6)
974 add_s_sclr:
975 lea.l WBTEMP(a6),a0
976 move.l FPTEMP(a6),(a0) ;write result to wbtemp
977 move.l FPTEMP_HI(a6),4(a0)
978 move.l FPTEMP_LO(a6),8(a0)
979 tst.w FPTEMP_EX(a6)
980 bgt add_ckovf
981 or.l #neg_mask,USER_FPSR(a6)
982 add_ckovf:
983 move.w WBTEMP_EX(a6),d0
984 andi.w #$7fff,d0
985 cmpi.w #$7fff,d0
986 bne frcfpnr
987 *
988 * The result has overflowed to $7fff exponent. Set I, ovfl,
989 * and aovfl, and clr the mantissa (incorrectly set by the
990 * round routine.)
991 *
992 or.l #inf_mask+ovfl_inx_mask,USER_FPSR(a6)
993 clr.l 4(a0)
994 bra frcfpnr
995 *
996 * Inst is fsub.
997 *
998 wrap_sub:
999 cmp.b #$ff,DNRM_FLG(a6) ;if both ops denorm,
1000 beq fix_stk ;restore to fpu
1001 *
1002 * One of the ops is denormalized. Test for wrap condition
1003 * and complete the instruction.
1004 *
1005 cmp.b #$0f,DNRM_FLG(a6) ;check for dest denorm
1006 bne.b sub_srcd
1007 sub_destd:
1008 bsr.l ckinf_ns
1009 bne fix_stk
1010 bfextu ETEMP_EX(a6){1:15},d0 ;get src exp (always pos)
1011 bfexts FPTEMP_EX(a6){1:15},d1 ;get dest exp (always neg)
1012 sub.l d1,d0 ;subtract src from dest
1013 cmp.l #$8000,d0
1014 blt fix_stk ;if less, not wrap case
1015 bra sub_wrap
1016 sub_srcd:
1017 bsr.l ckinf_nd
1018 bne fix_stk
1019 bfextu FPTEMP_EX(a6){1:15},d0 ;get dest exp (always pos)
1020 bfexts ETEMP_EX(a6){1:15},d1 ;get src exp (always neg)
1021 sub.l d1,d0 ;subtract dest from src
1022 cmp.l #$8000,d0
1023 blt fix_stk ;if less, not wrap case
1024 *
1025 * Check the signs of the operands. If they are alike, the fpu
1026 * can be used to subtract from the norm 1.0 with the sign of the
1027 * denorm and it will correctly generate the result in extended
1028 * precision. We can then call round with no sticky and the result
1029 * will be correct for the user's rounding mode and precision. If
1030 * the signs are unlike, we call round with the sticky bit set
1031 * and the result will be correctfor the user's rounding mode and
1032 * precision.
1033 *
1034 sub_wrap:
1035 move.w ETEMP_EX(a6),d0
1036 move.w FPTEMP_EX(a6),d1
1037 eor.w d1,d0
1038 andi.w #$8000,d0
1039 bne sub_diff
1040 *
1041 * The signs are alike.
1042 *
1043 cmp.b #$0f,DNRM_FLG(a6) ;is dest the denorm?
1044 bne.b sub_u_srcd
1045 move.w FPTEMP_EX(a6),d0
1046 andi.w #$8000,d0
1047 or.w #$3fff,d0 ;force the exponent to +/- 1
1048 move.w d0,FPTEMP_EX(a6) ;in the denorm
1049 move.l USER_FPCR(a6),d0
1050 andi.l #$30,d0
1051 fmove.l d0,fpcr ;set up users rmode and X
1052 fmove.x FPTEMP(a6),fp0
1053 fsub.x ETEMP(a6),fp0
1054 fmove.l fpsr,d1
1055 or.l d1,USER_FPSR(a6) ;capture cc's and inex from fadd
1056 lea.l WBTEMP(a6),a0 ;point a0 to wbtemp in frame
1057 fmove.x fp0,WBTEMP(a6) ;write result to memory
1058 lsr.l #4,d0 ;put rmode in lower 2 bits
1059 move.l USER_FPCR(a6),d1
1060 andi.l #$c0,d1
1061 lsr.l #6,d1 ;put precision in upper word
1062 swap d1
1063 or.l d0,d1 ;set up for round call
1064 clr.l d0 ;force sticky to zero
1065 bclr.b #sign_bit,WBTEMP_EX(a6)
1066 sne WBTEMP_SGN(a6)
1067 bsr.l round ;round result to users rmode & prec
1068 bfclr WBTEMP_SGN(a6){0:8} ;convert back to IEEE ext format
1069 beq frcfpnr
1070 bset.b #sign_bit,WBTEMP_EX(a6)
1071 bra frcfpnr
1072 sub_u_srcd:
1073 move.w ETEMP_EX(a6),d0
1074 andi.w #$8000,d0
1075 or.w #$3fff,d0 ;force the exponent to +/- 1
1076 move.w d0,ETEMP_EX(a6) ;in the denorm
1077 move.l USER_FPCR(a6),d0
1078 andi.l #$30,d0
1079 fmove.l d0,fpcr ;set up users rmode and X
1080 fmove.x FPTEMP(a6),fp0
1081 fsub.x ETEMP(a6),fp0
1082 fmove.l fpsr,d1
1083 or.l d1,USER_FPSR(a6) ;capture cc's and inex from fadd
1084 lea.l WBTEMP(a6),a0 ;point a0 to wbtemp in frame
1085 fmove.x fp0,WBTEMP(a6) ;write result to memory
1086 lsr.l #4,d0 ;put rmode in lower 2 bits
1087 move.l USER_FPCR(a6),d1
1088 andi.l #$c0,d1
1089 lsr.l #6,d1 ;put precision in upper word
1090 swap d1
1091 or.l d0,d1 ;set up for round call
1092 clr.l d0 ;force sticky to zero
1093 bclr.b #sign_bit,WBTEMP_EX(a6)
1094 sne WBTEMP_SGN(a6)
1095 bsr.l round ;round result to users rmode & prec
1096 bfclr WBTEMP_SGN(a6){0:8} ;convert back to IEEE ext format
1097 beq frcfpnr
1098 bset.b #sign_bit,WBTEMP_EX(a6)
1099 bra frcfpnr
1100 *
1101 * Signs are unlike:
1102 *
1103 sub_diff:
1104 cmp.b #$0f,DNRM_FLG(a6) ;is dest the denorm?
1105 bne.b sub_s_srcd
1106 sub_s_destd:
1107 lea.l ETEMP(a6),a0
1108 move.l USER_FPCR(a6),d0
1109 andi.l #$30,d0
1110 lsr.l #4,d0 ;put rmode in lower 2 bits
1111 move.l USER_FPCR(a6),d1
1112 andi.l #$c0,d1
1113 lsr.l #6,d1 ;put precision in upper word
1114 swap d1
1115 or.l d0,d1 ;set up for round call
1116 move.l #$20000000,d0 ;set sticky for round
1117 *
1118 * Since the dest is the denorm, the sign is the opposite of the
1119 * norm sign.
1120 *
1121 eori.w #$8000,ETEMP_EX(a6) ;flip sign on result
1122 tst.w ETEMP_EX(a6)
1123 bgt.b sub_s_dwr
1124 or.l #neg_mask,USER_FPSR(a6)
1125 sub_s_dwr:
1126 bclr.b #sign_bit,ETEMP_EX(a6)
1127 sne ETEMP_SGN(a6)
1128 bsr.l round ;round result to users rmode & prec
1129 bfclr ETEMP_SGN(a6){0:8} ;convert back to IEEE ext format
1130 beq.b sub_s_dclr
1131 bset.b #sign_bit,ETEMP_EX(a6)
1132 sub_s_dclr:
1133 lea.l WBTEMP(a6),a0
1134 move.l ETEMP(a6),(a0) ;write result to wbtemp
1135 move.l ETEMP_HI(a6),4(a0)
1136 move.l ETEMP_LO(a6),8(a0)
1137 bra sub_ckovf
1138 sub_s_srcd:
1139 lea.l FPTEMP(a6),a0
1140 move.l USER_FPCR(a6),d0
1141 andi.l #$30,d0
1142 lsr.l #4,d0 ;put rmode in lower 2 bits
1143 move.l USER_FPCR(a6),d1
1144 andi.l #$c0,d1
1145 lsr.l #6,d1 ;put precision in upper word
1146 swap d1
1147 or.l d0,d1 ;set up for round call
1148 move.l #$20000000,d0 ;set sticky for round
1149 bclr.b #sign_bit,FPTEMP_EX(a6)
1150 sne FPTEMP_SGN(a6)
1151 bsr.l round ;round result to users rmode & prec
1152 bfclr FPTEMP_SGN(a6){0:8} ;convert back to IEEE ext format
1153 beq.b sub_s_sclr
1154 bset.b #sign_bit,FPTEMP_EX(a6)
1155 sub_s_sclr:
1156 lea.l WBTEMP(a6),a0
1157 move.l FPTEMP(a6),(a0) ;write result to wbtemp
1158 move.l FPTEMP_HI(a6),4(a0)
1159 move.l FPTEMP_LO(a6),8(a0)
1160 tst.w FPTEMP_EX(a6)
1161 bgt sub_ckovf
1162 or.l #neg_mask,USER_FPSR(a6)
1163 sub_ckovf:
1164 move.w WBTEMP_EX(a6),d0
1165 andi.w #$7fff,d0
1166 cmpi.w #$7fff,d0
1167 bne frcfpnr
1168 *
1169 * The result has overflowed to $7fff exponent. Set I, ovfl,
1170 * and aovfl, and clr the mantissa (incorrectly set by the
1171 * round routine.)
1172 *
1173 or.l #inf_mask+ovfl_inx_mask,USER_FPSR(a6)
1174 clr.l 4(a0)
1175 bra frcfpnr
1176 *
1177 * Inst is fcmp.
1178 *
1179 wrap_cmp:
1180 cmp.b #$ff,DNRM_FLG(a6) ;if both ops denorm,
1181 beq fix_stk ;restore to fpu
1182 *
1183 * One of the ops is denormalized. Test for wrap condition
1184 * and complete the instruction.
1185 *
1186 cmp.b #$0f,DNRM_FLG(a6) ;check for dest denorm
1187 bne.b cmp_srcd
1188 cmp_destd:
1189 bsr.l ckinf_ns
1190 bne fix_stk
1191 bfextu ETEMP_EX(a6){1:15},d0 ;get src exp (always pos)
1192 bfexts FPTEMP_EX(a6){1:15},d1 ;get dest exp (always neg)
1193 sub.l d1,d0 ;subtract dest from src
1194 cmp.l #$8000,d0
1195 blt fix_stk ;if less, not wrap case
1196 tst.w ETEMP_EX(a6) ;set N to ~sign_of(src)
1197 bge cmp_setn
1198 rts
1199 cmp_srcd:
1200 bsr.l ckinf_nd
1201 bne fix_stk
1202 bfextu FPTEMP_EX(a6){1:15},d0 ;get dest exp (always pos)
1203 bfexts ETEMP_EX(a6){1:15},d1 ;get src exp (always neg)
1204 sub.l d1,d0 ;subtract src from dest
1205 cmp.l #$8000,d0
1206 blt fix_stk ;if less, not wrap case
1207 tst.w FPTEMP_EX(a6) ;set N to sign_of(dest)
1208 blt cmp_setn
1209 rts
1210 cmp_setn:
1211 or.l #neg_mask,USER_FPSR(a6)
1212 rts
1214 *
1215 * Inst is fmul.
1216 *
1217 wrap_mul:
1218 cmp.b #$ff,DNRM_FLG(a6) ;if both ops denorm,
1219 beq force_unf ;force an underflow (really!)
1220 *
1221 * One of the ops is denormalized. Test for wrap condition
1222 * and complete the instruction.
1223 *
1224 cmp.b #$0f,DNRM_FLG(a6) ;check for dest denorm
1225 bne.b mul_srcd
1226 mul_destd:
1227 bsr.l ckinf_ns
1228 bne fix_stk
1229 bfextu ETEMP_EX(a6){1:15},d0 ;get src exp (always pos)
1230 bfexts FPTEMP_EX(a6){1:15},d1 ;get dest exp (always neg)
1231 add.l d1,d0 ;subtract dest from src
1232 bgt fix_stk
1233 bra force_unf
1234 mul_srcd:
1235 bsr.l ckinf_nd
1236 bne fix_stk
1237 bfextu FPTEMP_EX(a6){1:15},d0 ;get dest exp (always pos)
1238 bfexts ETEMP_EX(a6){1:15},d1 ;get src exp (always neg)
1239 add.l d1,d0 ;subtract src from dest
1240 bgt fix_stk
1242 *
1243 * This code handles the case of the instruction resulting in
1244 * an underflow condition.
1245 *
1246 force_unf:
1247 bclr.b #E1,E_BYTE(a6)
1248 or.l #unfinx_mask,USER_FPSR(a6)
1249 clr.w NMNEXC(a6)
1250 clr.b WBTEMP_SGN(a6)
1251 move.w ETEMP_EX(a6),d0 ;find the sign of the result
1252 move.w FPTEMP_EX(a6),d1
1253 eor.w d1,d0
1254 andi.w #$8000,d0
1255 beq.b frcunfcont
1256 st.b WBTEMP_SGN(a6)
1257 frcunfcont:
1258 lea WBTEMP(a6),a0 ;point a0 to memory location
1259 move.w CMDREG1B(a6),d0
1260 btst.l #6,d0 ;test for forced precision
1261 beq.b frcunf_fpcr
1262 btst.l #2,d0 ;check for double
1263 bne.b frcunf_dbl
1264 move.l #$1,d0 ;inst is forced single
1265 bra.b frcunf_rnd
1266 frcunf_dbl:
1267 move.l #$2,d0 ;inst is forced double
1268 bra.b frcunf_rnd
1269 frcunf_fpcr:
1270 bfextu FPCR_MODE(a6){0:2},d0 ;inst not forced - use fpcr prec
1271 frcunf_rnd:
1272 bsr.l unf_sub ;get correct result based on
1273 * ;round precision/mode. This
1274 * ;sets FPSR_CC correctly
1275 bfclr WBTEMP_SGN(a6){0:8} ;convert back to IEEE ext format
1276 beq.b frcfpn
1277 bset.b #sign_bit,WBTEMP_EX(a6)
1278 bra frcfpn
1280 *
1281 * Write the result to the user's fpn. All results must be HUGE to be
1282 * written; otherwise the results would have overflowed or underflowed.
1283 * If the rounding precision is single or double, the ovf_res routine
1284 * is needed to correctly supply the max value.
1285 *
1286 frcfpnr:
1287 move.w CMDREG1B(a6),d0
1288 btst.l #6,d0 ;test for forced precision
1289 beq.b frcfpn_fpcr
1290 btst.l #2,d0 ;check for double
1291 bne.b frcfpn_dbl
1292 move.l #$1,d0 ;inst is forced single
1293 bra.b frcfpn_rnd
1294 frcfpn_dbl:
1295 move.l #$2,d0 ;inst is forced double
1296 bra.b frcfpn_rnd
1297 frcfpn_fpcr:
1298 bfextu FPCR_MODE(a6){0:2},d0 ;inst not forced - use fpcr prec
1299 tst.b d0
1300 beq.b frcfpn ;if extended, write what you got
1301 frcfpn_rnd:
1302 bclr.b #sign_bit,WBTEMP_EX(a6)
1303 sne WBTEMP_SGN(a6)
1304 bsr.l ovf_res ;get correct result based on
1305 * ;round precision/mode. This
1306 * ;sets FPSR_CC correctly
1307 bfclr WBTEMP_SGN(a6){0:8} ;convert back to IEEE ext format
1308 beq.b frcfpn_clr
1309 bset.b #sign_bit,WBTEMP_EX(a6)
1310 frcfpn_clr:
1311 or.l #ovfinx_mask,USER_FPSR(a6)
1312 *
1313 * Perform the write.
1314 *
1315 frcfpn:
1316 bfextu CMDREG1B(a6){6:3},d0 ;extract fp destination register
1317 cmpi.b #3,d0
1318 ble.b frc0123 ;check if dest is fp0-fp3
1319 move.l #7,d1
1320 sub.l d0,d1
1321 clr.l d0
1322 bset.l d1,d0
1323 fmovem.x WBTEMP(a6),d0
1324 rts
1325 frc0123:
1326 tst.b d0
1327 beq.b frc0_dst
1328 cmpi.b #1,d0
1329 beq.b frc1_dst
1330 cmpi.b #2,d0
1331 beq.b frc2_dst
1332 frc3_dst:
1333 move.l WBTEMP_EX(a6),USER_FP3(a6)
1334 move.l WBTEMP_HI(a6),USER_FP3+4(a6)
1335 move.l WBTEMP_LO(a6),USER_FP3+8(a6)
1336 rts
1337 frc2_dst:
1338 move.l WBTEMP_EX(a6),USER_FP2(a6)
1339 move.l WBTEMP_HI(a6),USER_FP2+4(a6)
1340 move.l WBTEMP_LO(a6),USER_FP2+8(a6)
1341 rts
1342 frc1_dst:
1343 move.l WBTEMP_EX(a6),USER_FP1(a6)
1344 move.l WBTEMP_HI(a6),USER_FP1+4(a6)
1345 move.l WBTEMP_LO(a6),USER_FP1+8(a6)
1346 rts
1347 frc0_dst:
1348 move.l WBTEMP_EX(a6),USER_FP0(a6)
1349 move.l WBTEMP_HI(a6),USER_FP0+4(a6)
1350 move.l WBTEMP_LO(a6),USER_FP0+8(a6)
1351 rts
1353 *
1354 * Write etemp to fpn.
1355 * A check is made on enabled and signalled snan exceptions,
1356 * and the destination is not overwritten if this condition exists.
1357 * This code is designed to make fmoveins of unsupported data types
1358 * faster.
1359 *
1360 wr_etemp:
1361 btst.b #snan_bit,FPSR_EXCEPT(a6) ;if snan is set, and
1362 beq.b fmoveinc ;enabled, force restore
1363 btst.b #snan_bit,FPCR_ENABLE(a6) ;and don't overwrite
1364 beq.b fmoveinc ;the dest
1365 move.l ETEMP_EX(a6),FPTEMP_EX(a6) ;set up fptemp sign for
1366 * ;snan handler
1367 tst.b ETEMP(a6) ;check for negative
1368 blt.b snan_neg
1369 rts
1370 snan_neg:
1371 or.l #neg_bit,USER_FPSR(a6) ;snan is negative; set N
1372 rts
1373 fmoveinc:
1374 clr.w NMNEXC(a6)
1375 bclr.b #E1,E_BYTE(a6)
1376 move.b STAG(a6),d0 ;check if stag is inf
1377 andi.b #$e0,d0
1378 cmpi.b #$40,d0
1379 bne.b fminc_cnan
1380 or.l #inf_mask,USER_FPSR(a6) ;if inf, nothing yet has set I
1381 tst.w LOCAL_EX(a0) ;check sign
1382 bge.b fminc_con
1383 or.l #neg_mask,USER_FPSR(a6)
1384 bra fminc_con
1385 fminc_cnan:
1386 cmpi.b #$60,d0 ;check if stag is NaN
1387 bne.b fminc_czero
1388 or.l #nan_mask,USER_FPSR(a6) ;if nan, nothing yet has set NaN
1389 move.l ETEMP_EX(a6),FPTEMP_EX(a6) ;set up fptemp sign for
1390 * ;snan handler
1391 tst.w LOCAL_EX(a0) ;check sign
1392 bge.b fminc_con
1393 or.l #neg_mask,USER_FPSR(a6)
1394 bra fminc_con
1395 fminc_czero:
1396 cmpi.b #$20,d0 ;check if zero
1397 bne.b fminc_con
1398 or.l #z_mask,USER_FPSR(a6) ;if zero, set Z
1399 tst.w LOCAL_EX(a0) ;check sign
1400 bge.b fminc_con
1401 or.l #neg_mask,USER_FPSR(a6)
1402 fminc_con:
1403 bfextu CMDREG1B(a6){6:3},d0 ;extract fp destination register
1404 cmpi.b #3,d0
1405 ble.b fp0123 ;check if dest is fp0-fp3
1406 move.l #7,d1
1407 sub.l d0,d1
1408 clr.l d0
1409 bset.l d1,d0
1410 fmovem.x ETEMP(a6),d0
1411 rts
1413 fp0123:
1414 tst.b d0
1415 beq.b fp0_dst
1416 cmpi.b #1,d0
1417 beq.b fp1_dst
1418 cmpi.b #2,d0
1419 beq.b fp2_dst
1420 fp3_dst:
1421 move.l ETEMP_EX(a6),USER_FP3(a6)
1422 move.l ETEMP_HI(a6),USER_FP3+4(a6)
1423 move.l ETEMP_LO(a6),USER_FP3+8(a6)
1424 rts
1425 fp2_dst:
1426 move.l ETEMP_EX(a6),USER_FP2(a6)
1427 move.l ETEMP_HI(a6),USER_FP2+4(a6)
1428 move.l ETEMP_LO(a6),USER_FP2+8(a6)
1429 rts
1430 fp1_dst:
1431 move.l ETEMP_EX(a6),USER_FP1(a6)
1432 move.l ETEMP_HI(a6),USER_FP1+4(a6)
1433 move.l ETEMP_LO(a6),USER_FP1+8(a6)
1434 rts
1435 fp0_dst:
1436 move.l ETEMP_EX(a6),USER_FP0(a6)
1437 move.l ETEMP_HI(a6),USER_FP0+4(a6)
1438 move.l ETEMP_LO(a6),USER_FP0+8(a6)
1439 rts
1441 opclass3:
1442 st.b CU_ONLY(a6)
1443 move.w CMDREG1B(a6),d0 ;check if packed moveout
1444 andi.w #$0c00,d0 ;isolate last 2 bits of size field
1445 cmpi.w #$0c00,d0 ;if size is 011 or 111, it is packed
1446 beq.w pack_out ;else it is norm or denorm
1447 bra.w mv_out
1450 *
1451 * MOVE OUT
1452 *
1454 mv_tbl:
1455 dc.l li
1456 dc.l sgp
1457 dc.l xp
1458 dc.l mvout_end ;should never be taken
1459 dc.l wi
1460 dc.l dp
1461 dc.l bi
1462 dc.l mvout_end ;should never be taken
1463 mv_out:
1464 bfextu CMDREG1B(a6){3:3},d1 ;put source specifier in d1
1465 lea.l mv_tbl,a0
1466 move.l (a0,d1*4),a0
1467 jmp (a0)
1469 *
1470 * This exit is for move-out to memory. The aunfl bit is
1471 * set if the result is inex and unfl is signalled.
1472 *
1473 mvout_end:
1474 btst.b #inex2_bit,FPSR_EXCEPT(a6)
1475 beq.b no_aufl
1476 btst.b #unfl_bit,FPSR_EXCEPT(a6)
1477 beq.b no_aufl
1478 bset.b #aunfl_bit,FPSR_AEXCEPT(a6)
1479 no_aufl:
1480 clr.w NMNEXC(a6)
1481 bclr.b #E1,E_BYTE(a6)
1482 fmove.l #0,FPSR ;clear any cc bits from res_func
1483 *
1484 * Return ETEMP to extended format from internal extended format so
1485 * that gen_except will have a correctly signed value for ovfl/unfl
1486 * handlers.
1487 *
1488 bfclr ETEMP_SGN(a6){0:8}
1489 beq.b mvout_con
1490 bset.b #sign_bit,ETEMP_EX(a6)
1491 mvout_con:
1492 rts
1493 *
1494 * This exit is for move-out to int register. The aunfl bit is
1495 * not set in any case for this move.
1496 *
1497 mvouti_end:
1498 clr.w NMNEXC(a6)
1499 bclr.b #E1,E_BYTE(a6)
1500 fmove.l #0,FPSR ;clear any cc bits from res_func
1501 *
1502 * Return ETEMP to extended format from internal extended format so
1503 * that gen_except will have a correctly signed value for ovfl/unfl
1504 * handlers.
1505 *
1506 bfclr ETEMP_SGN(a6){0:8}
1507 beq.b mvouti_con
1508 bset.b #sign_bit,ETEMP_EX(a6)
1509 mvouti_con:
1510 rts
1511 *
1512 * li is used to handle a long integer source specifier
1513 *
1515 li:
1516 moveq.l #4,d0 ;set byte count
1518 btst.b #7,STAG(a6) ;check for extended denorm
1519 bne.w int_dnrm ;if so, branch
1521 fmovem.x ETEMP(a6),fp0
1522 fcmp.d #:41dfffffffc00000,fp0
1523 * 41dfffffffc00000 in dbl prec = 401d0000fffffffe00000000 in ext prec
1524 fbge.w lo_plrg
1525 fcmp.d #:c1e0000000000000,fp0
1526 * c1e0000000000000 in dbl prec = c01e00008000000000000000 in ext prec
1527 fble.w lo_nlrg
1528 *
1529 * at this point, the answer is between the largest pos and neg values
1530 *
1531 move.l USER_FPCR(a6),d1 ;use user's rounding mode
1532 andi.l #$30,d1
1533 fmove.l d1,fpcr
1534 fmove.l fp0,L_SCR1(a6) ;let the 040 perform conversion
1535 fmove.l fpsr,d1
1536 or.l d1,USER_FPSR(a6) ;capture inex2/ainex if set
1537 bra.w int_wrt
1540 lo_plrg:
1541 move.l #$7fffffff,L_SCR1(a6) ;answer is largest positive int
1542 fbeq.w int_wrt ;exact answer
1543 fcmp.d #:41dfffffffe00000,fp0
1544 * 41dfffffffe00000 in dbl prec = 401d0000ffffffff00000000 in ext prec
1545 fbge.w int_operr ;set operr
1546 bra.w int_inx ;set inexact
1548 lo_nlrg:
1549 move.l #$80000000,L_SCR1(a6)
1550 fbeq.w int_wrt ;exact answer
1551 fcmp.d #:c1e0000000100000,fp0
1552 * c1e0000000100000 in dbl prec = c01e00008000000080000000 in ext prec
1553 fblt.w int_operr ;set operr
1554 bra.w int_inx ;set inexact
1556 *
1557 * wi is used to handle a word integer source specifier
1558 *
1560 wi:
1561 moveq.l #2,d0 ;set byte count
1563 btst.b #7,STAG(a6) ;check for extended denorm
1564 bne.w int_dnrm ;branch if so
1566 fmovem.x ETEMP(a6),fp0
1567 fcmp.s #:46fffe00,fp0
1568 * 46fffe00 in sgl prec = 400d0000fffe000000000000 in ext prec
1569 fbge.w wo_plrg
1570 fcmp.s #:c7000000,fp0
1571 * c7000000 in sgl prec = c00e00008000000000000000 in ext prec
1572 fble.w wo_nlrg
1574 *
1575 * at this point, the answer is between the largest pos and neg values
1576 *
1577 move.l USER_FPCR(a6),d1 ;use user's rounding mode
1578 andi.l #$30,d1
1579 fmove.l d1,fpcr
1580 fmove.w fp0,L_SCR1(a6) ;let the 040 perform conversion
1581 fmove.l fpsr,d1
1582 or.l d1,USER_FPSR(a6) ;capture inex2/ainex if set
1583 bra.w int_wrt
1585 wo_plrg:
1586 move.w #$7fff,L_SCR1(a6) ;answer is largest positive int
1587 fbeq.w int_wrt ;exact answer
1588 fcmp.s #:46ffff00,fp0
1589 * 46ffff00 in sgl prec = 400d0000ffff000000000000 in ext prec
1590 fbge.w int_operr ;set operr
1591 bra.w int_inx ;set inexact
1593 wo_nlrg:
1594 move.w #$8000,L_SCR1(a6)
1595 fbeq.w int_wrt ;exact answer
1596 fcmp.s #:c7000080,fp0
1597 * c7000080 in sgl prec = c00e00008000800000000000 in ext prec
1598 fblt.w int_operr ;set operr
1599 bra.w int_inx ;set inexact
1601 *
1602 * bi is used to handle a byte integer source specifier
1603 *
1605 bi:
1606 moveq.l #1,d0 ;set byte count
1608 btst.b #7,STAG(a6) ;check for extended denorm
1609 bne.w int_dnrm ;branch if so
1611 fmovem.x ETEMP(a6),fp0
1612 fcmp.s #:42fe0000,fp0
1613 * 42fe0000 in sgl prec = 40050000fe00000000000000 in ext prec
1614 fbge.w by_plrg
1615 fcmp.s #:c3000000,fp0
1616 * c3000000 in sgl prec = c00600008000000000000000 in ext prec
1617 fble.w by_nlrg
1619 *
1620 * at this point, the answer is between the largest pos and neg values
1621 *
1622 move.l USER_FPCR(a6),d1 ;use user's rounding mode
1623 andi.l #$30,d1
1624 fmove.l d1,fpcr
1625 fmove.b fp0,L_SCR1(a6) ;let the 040 perform conversion
1626 fmove.l fpsr,d1
1627 or.l d1,USER_FPSR(a6) ;capture inex2/ainex if set
1628 bra.w int_wrt
1630 by_plrg:
1631 move.b #$7f,L_SCR1(a6) ;answer is largest positive int
1632 fbeq.w int_wrt ;exact answer
1633 fcmp.s #:42ff0000,fp0
1634 * 42ff0000 in sgl prec = 40050000ff00000000000000 in ext prec
1635 fbge.w int_operr ;set operr
1636 bra.w int_inx ;set inexact
1638 by_nlrg:
1639 move.b #$80,L_SCR1(a6)
1640 fbeq.w int_wrt ;exact answer
1641 fcmp.s #:c3008000,fp0
1642 * c3008000 in sgl prec = c00600008080000000000000 in ext prec
1643 fblt.w int_operr ;set operr
1644 bra.w int_inx ;set inexact
1646 *
1647 * Common integer routines
1648 *
1649 * int_drnrm---account for possible nonzero result for round up with positive
1650 * operand and round down for negative answer. In the first case (result = 1)
1651 * byte-width (store in d0) of result must be honored. In the second case,
1652 * -1 in L_SCR1(a6) will cover all contingencies (FMOVE.B/W/L out).
1654 int_dnrm:
1655 clr.l L_SCR1(a6) ; initialize result to 0
1656 bfextu FPCR_MODE(a6){2:2},d1 ; d1 is the rounding mode
1657 cmp.b #2,d1
1658 bmi.b int_inx ; if RN or RZ, done
1659 bne.b int_rp ; if RP, continue below
1660 tst.w ETEMP(a6) ; RM: store -1 in L_SCR1 if src is negative
1661 bpl.b int_inx ; otherwise result is 0
1662 move.l #-1,L_SCR1(a6)
1663 bra.b int_inx
1664 int_rp:
1665 tst.w ETEMP(a6) ; RP: store +1 of proper width in L_SCR1 if
1666 * ; source is greater than 0
1667 bmi.b int_inx ; otherwise, result is 0
1668 lea L_SCR1(a6),a1 ; a1 is address of L_SCR1
1669 adda.l d0,a1 ; offset by destination width -1
1670 suba.l #1,a1
1671 bset.b #0,(a1) ; set low bit at a1 address
1672 int_inx:
1673 ori.l #inx2a_mask,USER_FPSR(a6)
1674 bra.b int_wrt
1675 int_operr:
1676 fmovem.x fp0,FPTEMP(a6) ;FPTEMP must contain the extended
1677 * ;precision source that needs to be
1678 * ;converted to integer this is required
1679 * ;if the operr exception is enabled.
1680 * ;set operr/aiop (no inex2 on int ovfl)
1682 ori.l #opaop_mask,USER_FPSR(a6)
1683 * ;fall through to perform int_wrt
1684 int_wrt:
1685 move.l EXC_EA(a6),a1 ;load destination address
1686 tst.l a1 ;check to see if it is a dest register
1687 beq.b wrt_dn ;write data register
1688 lea L_SCR1(a6),a0 ;point to supervisor source address
1689 bsr.l mem_write
1690 bra.w mvouti_end
1692 wrt_dn:
1693 move.l d0,-(sp) ;d0 currently contains the size to write
1694 bsr.l get_fline ;get_fline returns Dn in d0
1695 andi.w #$7,d0 ;isolate register
1696 move.l (sp)+,d1 ;get size
1697 cmpi.l #4,d1 ;most frequent case
1698 beq.b sz_long
1699 cmpi.l #2,d1
1700 bne.b sz_con
1701 or.l #8,d0 ;add 'word' size to register#
1702 bra.b sz_con
1703 sz_long:
1704 or.l #$10,d0 ;add 'long' size to register#
1705 sz_con:
1706 move.l d0,d1 ;reg_dest expects size:reg in d1
1707 bsr.l reg_dest ;load proper data register
1708 bra.w mvouti_end
1709 xp:
1710 lea ETEMP(a6),a0
1711 bclr.b #sign_bit,LOCAL_EX(a0)
1712 sne LOCAL_SGN(a0)
1713 btst.b #7,STAG(a6) ;check for extended denorm
1714 bne.w xdnrm
1715 clr.l d0
1716 bra.b do_fp ;do normal case
1717 sgp:
1718 lea ETEMP(a6),a0
1719 bclr.b #sign_bit,LOCAL_EX(a0)
1720 sne LOCAL_SGN(a0)
1721 btst.b #7,STAG(a6) ;check for extended denorm
1722 bne.w sp_catas ;branch if so
1723 move.w LOCAL_EX(a0),d0
1724 lea sp_bnds,a1
1725 cmp.w (a1),d0
1726 blt.w sp_under
1727 cmp.w 2(a1),d0
1728 bgt.w sp_over
1729 move.l #1,d0 ;set destination format to single
1730 bra.b do_fp ;do normal case
1731 dp:
1732 lea ETEMP(a6),a0
1733 bclr.b #sign_bit,LOCAL_EX(a0)
1734 sne LOCAL_SGN(a0)
1736 btst.b #7,STAG(a6) ;check for extended denorm
1737 bne.w dp_catas ;branch if so
1739 move.w LOCAL_EX(a0),d0
1740 lea dp_bnds,a1
1742 cmp.w (a1),d0
1743 blt.w dp_under
1744 cmp.w 2(a1),d0
1745 bgt.w dp_over
1747 move.l #2,d0 ;set destination format to double
1748 * ;fall through to do_fp
1749 *
1750 do_fp:
1751 bfextu FPCR_MODE(a6){2:2},d1 ;rnd mode in d1
1752 swap d0 ;rnd prec in upper word
1753 add.l d0,d1 ;d1 has PREC/MODE info
1755 clr.l d0 ;clear g,r,s
1757 bsr.l round ;round
1759 move.l a0,a1
1760 move.l EXC_EA(a6),a0
1762 bfextu CMDREG1B(a6){3:3},d1 ;extract destination format
1763 * ;at this point only the dest
1764 * ;formats sgl, dbl, ext are
1765 * ;possible
1766 cmp.b #2,d1
1767 bgt.b ddbl ;double=5, extended=2, single=1
1768 bne.b dsgl
1769 * ;fall through to dext
1770 dext:
1771 bsr.l dest_ext
1772 bra.w mvout_end
1773 dsgl:
1774 bsr.l dest_sgl
1775 bra.w mvout_end
1776 ddbl:
1777 bsr.l dest_dbl
1778 bra.w mvout_end
1780 *
1781 * Handle possible denorm or catastrophic underflow cases here
1782 *
1783 xdnrm:
1784 bsr.w set_xop ;initialize WBTEMP
1785 bset.b #wbtemp15_bit,WB_BYTE(a6) ;set wbtemp15
1787 move.l a0,a1
1788 move.l EXC_EA(a6),a0 ;a0 has the destination pointer
1789 bsr.l dest_ext ;store to memory
1790 bset.b #unfl_bit,FPSR_EXCEPT(a6)
1791 bra.w mvout_end
1793 sp_under:
1794 bset.b #etemp15_bit,STAG(a6)
1796 cmp.w 4(a1),d0
1797 blt.b sp_catas ;catastrophic underflow case
1799 move.l #1,d0 ;load in round precision
1800 move.l #sgl_thresh,d1 ;load in single denorm threshold
1801 bsr.l dpspdnrm ;expects d1 to have the proper
1802 * ;denorm threshold
1803 bsr.l dest_sgl ;stores value to destination
1804 bset.b #unfl_bit,FPSR_EXCEPT(a6)
1805 bra.w mvout_end ;exit
1807 dp_under:
1808 bset.b #etemp15_bit,STAG(a6)
1810 cmp.w 4(a1),d0
1811 blt.b dp_catas ;catastrophic underflow case
1813 move.l #dbl_thresh,d1 ;load in double precision threshold
1814 move.l #2,d0
1815 bsr.l dpspdnrm ;expects d1 to have proper
1816 * ;denorm threshold
1817 * ;expects d0 to have round precision
1818 bsr.l dest_dbl ;store value to destination
1819 bset.b #unfl_bit,FPSR_EXCEPT(a6)
1820 bra.w mvout_end ;exit
1822 *
1823 * Handle catastrophic underflow cases here
1824 *
1825 sp_catas:
1826 * Temp fix for z bit set in unf_sub
1827 move.l USER_FPSR(a6),-(a7)
1829 move.l #1,d0 ;set round precision to sgl
1831 bsr.l unf_sub ;a0 points to result
1833 move.l (a7)+,USER_FPSR(a6)
1835 move.l #1,d0
1836 sub.w d0,LOCAL_EX(a0) ;account for difference between
1837 * ;denorm/norm bias
1839 move.l a0,a1 ;a1 has the operand input
1840 move.l EXC_EA(a6),a0 ;a0 has the destination pointer
1842 bsr.l dest_sgl ;store the result
1843 ori.l #unfinx_mask,USER_FPSR(a6)
1844 bra.w mvout_end
1846 dp_catas:
1847 * Temp fix for z bit set in unf_sub
1848 move.l USER_FPSR(a6),-(a7)
1850 move.l #2,d0 ;set round precision to dbl
1851 bsr.l unf_sub ;a0 points to result
1853 move.l (a7)+,USER_FPSR(a6)
1855 move.l #1,d0
1856 sub.w d0,LOCAL_EX(a0) ;account for difference between
1857 * ;denorm/norm bias
1859 move.l a0,a1 ;a1 has the operand input
1860 move.l EXC_EA(a6),a0 ;a0 has the destination pointer
1862 bsr.l dest_dbl ;store the result
1863 ori.l #unfinx_mask,USER_FPSR(a6)
1864 bra.w mvout_end
1866 *
1867 * Handle catastrophic overflow cases here
1868 *
1869 sp_over:
1870 * Temp fix for z bit set in unf_sub
1871 move.l USER_FPSR(a6),-(a7)
1873 move.l #1,d0
1874 lea.l FP_SCR1(a6),a0 ;use FP_SCR1 for creating result
1875 move.l ETEMP_EX(a6),(a0)
1876 move.l ETEMP_HI(a6),4(a0)
1877 move.l ETEMP_LO(a6),8(a0)
1878 bsr.l ovf_res
1880 move.l (a7)+,USER_FPSR(a6)
1882 move.l a0,a1
1883 move.l EXC_EA(a6),a0
1884 bsr.l dest_sgl
1885 or.l #ovfinx_mask,USER_FPSR(a6)
1886 bra.w mvout_end
1888 dp_over:
1889 * Temp fix for z bit set in ovf_res
1890 move.l USER_FPSR(a6),-(a7)
1892 move.l #2,d0
1893 lea.l FP_SCR1(a6),a0 ;use FP_SCR1 for creating result
1894 move.l ETEMP_EX(a6),(a0)
1895 move.l ETEMP_HI(a6),4(a0)
1896 move.l ETEMP_LO(a6),8(a0)
1897 bsr.l ovf_res
1899 move.l (a7)+,USER_FPSR(a6)
1901 move.l a0,a1
1902 move.l EXC_EA(a6),a0
1903 bsr.l dest_dbl
1904 or.l #ovfinx_mask,USER_FPSR(a6)
1905 bra.w mvout_end
1907 *
1908 * DPSPDNRM
1909 *
1910 * This subroutine takes an extended normalized number and denormalizes
1911 * it to the given round precision. This subroutine also decrements
1912 * the input operand's exponent by 1 to account for the fact that
1913 * dest_sgl or dest_dbl expects a normalized number's bias.
1914 *
1915 * Input: a0 points to a normalized number in internal extended format
1916 * d0 is the round precision (=1 for sgl; =2 for dbl)
1917 * d1 is the single precision or double precision
1918 * denorm threshold
1919 *
1920 * Output: (In the format for dest_sgl or dest_dbl)
1921 * a0 points to the destination
1922 * a1 points to the operand
1923 *
1924 * Exceptions: Reports inexact 2 exception by setting USER_FPSR bits
1925 *
1926 dpspdnrm:
1927 move.l d0,-(a7) ;save round precision
1928 clr.l d0 ;clear initial g,r,s
1929 bsr.l dnrm_lp ;careful with d0, it's needed by round
1931 bfextu FPCR_MODE(a6){2:2},d1 ;get rounding mode
1932 swap d1
1933 move.w 2(a7),d1 ;set rounding precision
1934 swap d1 ;at this point d1 has PREC/MODE info
1935 bsr.l round ;round result, sets the inex bit in
1936 * ;USER_FPSR if needed
1938 move.w #1,d0
1939 sub.w d0,LOCAL_EX(a0) ;account for difference in denorm
1940 * ;vs norm bias
1942 move.l a0,a1 ;a1 has the operand input
1943 move.l EXC_EA(a6),a0 ;a0 has the destination pointer
1944 addq.l #4,a7 ;pop stack
1945 rts
1946 *
1947 * SET_XOP initialized WBTEMP with the value pointed to by a0
1948 * input: a0 points to input operand in the internal extended format
1949 *
1950 set_xop:
1951 move.l LOCAL_EX(a0),WBTEMP_EX(a6)
1952 move.l LOCAL_HI(a0),WBTEMP_HI(a6)
1953 move.l LOCAL_LO(a0),WBTEMP_LO(a6)
1954 bfclr WBTEMP_SGN(a6){0:8}
1955 beq.b sxop
1956 bset.b #sign_bit,WBTEMP_EX(a6)
1957 sxop:
1958 bfclr STAG(a6){5:4} ;clear wbtm66,wbtm1,wbtm0,sbit
1959 rts
1960 *
1961 * P_MOVE
1962 *
1963 p_movet:
1964 dc.l p_move
1965 dc.l p_movez
1966 dc.l p_movei
1967 dc.l p_moven
1968 dc.l p_move
1969 p_regd:
1970 dc.l p_dyd0
1971 dc.l p_dyd1
1972 dc.l p_dyd2
1973 dc.l p_dyd3
1974 dc.l p_dyd4
1975 dc.l p_dyd5
1976 dc.l p_dyd6
1977 dc.l p_dyd7
1979 pack_out:
1980 lea.l p_movet,a0 ;load jmp table address
1981 move.w STAG(a6),d0 ;get source tag
1982 bfextu d0{16:3},d0 ;isolate source bits
1983 move.l (a0,d0.w*4),a0 ;load a0 with routine label for tag
1984 jmp (a0) ;go to the routine
1986 p_write:
1987 move.l #$0c,d0 ;get byte count
1988 move.l EXC_EA(a6),a1 ;get the destination address
1989 bsr mem_write ;write the user's destination
1990 clr.b CU_SAVEPC(a6) ;set the cu save pc to all 0's
1992 *
1993 * Also note that the dtag must be set to norm here - this is because
1994 * the 040 uses the dtag to execute the correct microcode.
1995 *
1996 bfclr DTAG(a6){0:3} ;set dtag to norm
1998 rts
2000 * Notes on handling of special case (zero, inf, and nan) inputs:
2001 * 1. Operr is not signalled if the k-factor is greater than 18.
2002 * 2. Per the manual, status bits are not set.
2003 *
2005 p_move:
2006 move.w CMDREG1B(a6),d0
2007 btst.l #kfact_bit,d0 ;test for dynamic k-factor
2008 beq.b statick ;if clear, k-factor is static
2009 dynamick:
2010 bfextu d0{25:3},d0 ;isolate register for dynamic k-factor
2011 lea p_regd,a0
2012 move.l (a0,d0*4),a0
2013 jmp (a0)
2014 statick:
2015 andi.w #$007f,d0 ;get k-factor
2016 bfexts d0{25:7},d0 ;sign extend d0 for bindec
2017 lea.l ETEMP(a6),a0 ;a0 will point to the packed decimal
2018 bsr.l bindec ;perform the convert; data at a6
2019 lea.l FP_SCR1(a6),a0 ;load a0 with result address
2020 bra.l p_write
2021 p_movez:
2022 lea.l ETEMP(a6),a0 ;a0 will point to the packed decimal
2023 clr.w 2(a0) ;clear lower word of exp
2024 clr.l 4(a0) ;load second lword of ZERO
2025 clr.l 8(a0) ;load third lword of ZERO
2026 bra.w p_write ;go write results
2027 p_movei:
2028 fmove.l #0,FPSR ;clear aiop
2029 lea.l ETEMP(a6),a0 ;a0 will point to the packed decimal
2030 clr.w 2(a0) ;clear lower word of exp
2031 bra.w p_write ;go write the result
2032 p_moven:
2033 lea.l ETEMP(a6),a0 ;a0 will point to the packed decimal
2034 clr.w 2(a0) ;clear lower word of exp
2035 bra.w p_write ;go write the result
2037 *
2038 * Routines to read the dynamic k-factor from Dn.
2039 *
2040 p_dyd0:
2041 move.l USER_D0(a6),d0
2042 bra.b statick
2043 p_dyd1:
2044 move.l USER_D1(a6),d0
2045 bra.b statick
2046 p_dyd2:
2047 move.l d2,d0
2048 bra.b statick
2049 p_dyd3:
2050 move.l d3,d0
2051 bra.b statick
2052 p_dyd4:
2053 move.l d4,d0
2054 bra.b statick
2055 p_dyd5:
2056 move.l d5,d0
2057 bra.b statick
2058 p_dyd6:
2059 move.l d6,d0
2060 bra.w statick
2061 p_dyd7:
2062 move.l d7,d0
2063 bra.w statick
2065 end