1|
2| util.sa 3.7 7/29/91
3|
4| This file contains routines used by other programs.
5|
6| ovf_res: used by overflow to force the correct
7| result. ovf_r_k, ovf_r_x2, ovf_r_x3 are
8| derivatives of this routine.
9| get_fline: get user's opcode word
10| g_dfmtou: returns the destination format.
11| g_opcls: returns the opclass of the float instruction.
12| g_rndpr: returns the rounding precision.
13| reg_dest: write byte, word, or long data to Dn
14|
15|
16| Copyright (C) Motorola, Inc. 1990
17| All Rights Reserved
18|
19| For details on the license for this file, please see the
20| file, README, in this same directory.
21
22|UTIL idnt 2,1 | Motorola 040 Floating Point Software Package
23
24 |section 8
25
26#include "fpsp.h"
27
28 |xref mem_read
29
30 .global g_dfmtou
31 .global g_opcls
32 .global g_rndpr
33 .global get_fline
34 .global reg_dest
35
36|
37| Final result table for ovf_res. Note that the negative counterparts
38| are unnecessary as ovf_res always returns the sign separately from
39| the exponent.
40| ;+inf
41EXT_PINF: .long 0x7fff0000,0x00000000,0x00000000,0x00000000
42| ;largest +ext
43EXT_PLRG: .long 0x7ffe0000,0xffffffff,0xffffffff,0x00000000
44| ;largest magnitude +sgl in ext
45SGL_PLRG: .long 0x407e0000,0xffffff00,0x00000000,0x00000000
46| ;largest magnitude +dbl in ext
47DBL_PLRG: .long 0x43fe0000,0xffffffff,0xfffff800,0x00000000
48| ;largest -ext
49
50tblovfl:
51 .long EXT_RN
52 .long EXT_RZ
53 .long EXT_RM
54 .long EXT_RP
55 .long SGL_RN
56 .long SGL_RZ
57 .long SGL_RM
58 .long SGL_RP
59 .long DBL_RN
60 .long DBL_RZ
61 .long DBL_RM
62 .long DBL_RP
63 .long error
64 .long error
65 .long error
66 .long error
67
68
69|
70| ovf_r_k --- overflow result calculation
71|
72| This entry point is used by kernel_ex.
73|
74| This forces the destination precision to be extended
75|
76| Input: operand in ETEMP
77| Output: a result is in ETEMP (internal extended format)
78|
79 .global ovf_r_k
80ovf_r_k:
81 lea ETEMP(%a6),%a0 |a0 points to source operand
82 bclrb
83 sne ETEMP_SGN(%a6) |convert to internal IEEE format
84
85|
86| ovf_r_x2 --- overflow result calculation
87|
88| This entry point used by x_ovfl. (opclass 0 and 2)
89|
90| Input a0 points to an operand in the internal extended format
91| Output a0 points to the result in the internal extended format
92|
93| This sets the round precision according to the user's FPCR unless the
94| instruction is fsgldiv or fsglmul or fsadd, fdadd, fsub, fdsub, fsmul,
95| fdmul, fsdiv, fddiv, fssqrt, fsmove, fdmove, fsabs, fdabs, fsneg, fdneg.
96| If the instruction is fsgldiv of fsglmul, the rounding precision must be
97| extended. If the instruction is not fsgldiv or fsglmul but a force-
98| precision instruction, the rounding precision is then set to the force
99| precision.
100
101 .global ovf_r_x2
102ovf_r_x2:
103 btstb
104 beql ovf_e1_exc |it is cu exception
105ovf_e3_exc:
106 movew CMDREG3B(%a6),%d0 |get the command word
107 andiw
108 cmpil
109 beql ovff_sgl |force precision is single
110 cmpil
111 beql ovff_dbl |force precision is double
112 movew CMDREG3B(%a6),%d0 |get the command word again
113 andil
114 cmpil
115 beql ovf_fsgl |fsglmul or fsgldiv
116 cmpil
117 beql ovf_fsgl
118 bra ovf_fpcr |instruction is none of the above
119| ;use FPCR
120ovf_e1_exc:
121 movew CMDREG1B(%a6),%d0 |get command word
122 andil
123 cmpil
124 beql ovff_sgl |the instruction is force single
125 cmpil
126 beql ovff_dbl |the instruction is force double
127 movew CMDREG1B(%a6),%d0 |again get the command word
128 andil
129 cmpil
130 beql ovf_fsgl |fsglmul
131 cmpil
132 beql ovf_fsgl |fsgldiv
133 bra ovf_fpcr |none of the above, use FPCR
134|
135|
136| Inst is either fsgldiv or fsglmul. Force extended precision.
137|
138ovf_fsgl:
139 clrl %d0
140 bra ovf_res
141
142ovff_sgl:
143 movel
144 bra ovf_res
145ovff_dbl:
146 movel
147 bra ovf_res
148|
149| The precision is in the fpcr.
150|
151ovf_fpcr:
152 bfextu FPCR_MODE(%a6){
153 bra ovf_res
154
155|
156|
157| ovf_r_x3 --- overflow result calculation
158|
159| This entry point used by x_ovfl. (opclass 3 only)
160|
161| Input a0 points to an operand in the internal extended format
162| Output a0 points to the result in the internal extended format
163|
164| This sets the round precision according to the destination size.
165|
166 .global ovf_r_x3
167ovf_r_x3:
168 bsr g_dfmtou |get dest fmt in d0{1:0}
169| ;for fmovout, the destination format
170| ;is the rounding precision
171
172|
173| ovf_res --- overflow result calculation
174|
175| Input:
176| a0 points to operand in internal extended format
177| Output:
178| a0 points to result in internal extended format
179|
180 .global ovf_res
181ovf_res:
182 lsll
183 bfextu FPCR_MODE(%a6){
184 orl %d1,%d0 |index is fmt:mode in d0{3:0}
185 leal tblovfl,%a1 |load a1 with table address
186 movel %a1@(%d0:l:4),%a1 |use d0 as index to the table
187 jmp (%a1) |go to the correct routine
188|
189|case DEST_FMT = EXT
190|
191EXT_RN:
192 leal EXT_PINF,%a1 |answer is +/- infinity
193 bsetb
194 bra set_sign |now go set the sign
195EXT_RZ:
196 leal EXT_PLRG,%a1 |answer is +/- large number
197 bra set_sign |now go set the sign
198EXT_RM:
199 tstb LOCAL_SGN(%a0) |if negative overflow
200 beqs e_rm_pos
201e_rm_neg:
202 leal EXT_PINF,%a1 |answer is negative infinity
203 orl
204 bra end_ovfr
205e_rm_pos:
206 leal EXT_PLRG,%a1 |answer is large positive number
207 bra end_ovfr
208EXT_RP:
209 tstb LOCAL_SGN(%a0) |if negative overflow
210 beqs e_rp_pos
211e_rp_neg:
212 leal EXT_PLRG,%a1 |answer is large negative number
213 bsetb
214 bra end_ovfr
215e_rp_pos:
216 leal EXT_PINF,%a1 |answer is positive infinity
217 bsetb
218 bra end_ovfr
219|
220|case DEST_FMT = DBL
221|
222DBL_RN:
223 leal EXT_PINF,%a1 |answer is +/- infinity
224 bsetb
225 bra set_sign
226DBL_RZ:
227 leal DBL_PLRG,%a1 |answer is +/- large number
228 bra set_sign |now go set the sign
229DBL_RM:
230 tstb LOCAL_SGN(%a0) |if negative overflow
231 beqs d_rm_pos
232d_rm_neg:
233 leal EXT_PINF,%a1 |answer is negative infinity
234 orl
235 bra end_ovfr |inf is same for all precisions (ext,dbl,sgl)
236d_rm_pos:
237 leal DBL_PLRG,%a1 |answer is large positive number
238 bra end_ovfr
239DBL_RP:
240 tstb LOCAL_SGN(%a0) |if negative overflow
241 beqs d_rp_pos
242d_rp_neg:
243 leal DBL_PLRG,%a1 |answer is large negative number
244 bsetb
245 bra end_ovfr
246d_rp_pos:
247 leal EXT_PINF,%a1 |answer is positive infinity
248 bsetb
249 bra end_ovfr
250|
251|case DEST_FMT = SGL
252|
253SGL_RN:
254 leal EXT_PINF,%a1 |answer is +/- infinity
255 bsetb
256 bras set_sign
257SGL_RZ:
258 leal SGL_PLRG,%a1 |answer is +/- large number
259 bras set_sign
260SGL_RM:
261 tstb LOCAL_SGN(%a0) |if negative overflow
262 beqs s_rm_pos
263s_rm_neg:
264 leal EXT_PINF,%a1 |answer is negative infinity
265 orl
266 bras end_ovfr
267s_rm_pos:
268 leal SGL_PLRG,%a1 |answer is large positive number
269 bras end_ovfr
270SGL_RP:
271 tstb LOCAL_SGN(%a0) |if negative overflow
272 beqs s_rp_pos
273s_rp_neg:
274 leal SGL_PLRG,%a1 |answer is large negative number
275 bsetb
276 bras end_ovfr
277s_rp_pos:
278 leal EXT_PINF,%a1 |answer is positive infinity
279 bsetb
280 bras end_ovfr
281
282set_sign:
283 tstb LOCAL_SGN(%a0) |if negative overflow
284 beqs end_ovfr
285neg_sign:
286 bsetb
287
288end_ovfr:
289 movew LOCAL_EX(%a1),LOCAL_EX(%a0) |do not overwrite sign
290 movel LOCAL_HI(%a1),LOCAL_HI(%a0)
291 movel LOCAL_LO(%a1),LOCAL_LO(%a0)
292 rts
293
294
295|
296| ERROR
297|
298error:
299 rts
300|
301| get_fline --- get f-line opcode of interrupted instruction
302|
303| Returns opcode in the low word of d0.
304|
305get_fline:
306 movel USER_FPIAR(%a6),%a0 |opcode address
307 movel
308 leal 2(%a7),%a1 |point to low word of temporary
309 movel
310 bsrl mem_read
311 movel (%a7)+,%d0
312 rts
313|
314| g_rndpr --- put rounding precision in d0{1:0}
315|
316| valid return codes are:
317| 00 - extended
318| 01 - single
319| 10 - double
320|
321| begin
322| get rounding precision (cmdreg3b{6:5})
323| begin
324| case opclass = 011 (move out)
325| get destination format - this is the also the rounding precision
326|
327| case opclass = 0x0
328| if E3
329| *case RndPr(from cmdreg3b{6:5} = 11 then RND_PREC = DBL
330| *case RndPr(from cmdreg3b{6:5} = 10 then RND_PREC = SGL
331| case RndPr(from cmdreg3b{6:5} = 00 | 01
332| use precision from FPCR{7:6}
333| case 00 then RND_PREC = EXT
334| case 01 then RND_PREC = SGL
335| case 10 then RND_PREC = DBL
336| else E1
337| use precision in FPCR{7:6}
338| case 00 then RND_PREC = EXT
339| case 01 then RND_PREC = SGL
340| case 10 then RND_PREC = DBL
341| end
342|
343g_rndpr:
344 bsr g_opcls |get opclass in d0{2:0}
345 cmpw
346 bnes op_0x0
347
348|
349| For move out instructions (opclass 011) the destination format
350| is the same as the rounding precision. Pass results from g_dfmtou.
351|
352 bsr g_dfmtou
353 rts
354op_0x0:
355 btstb
356 beql unf_e1_exc |branch to e1 underflow
357unf_e3_exc:
358 movel CMDREG3B(%a6),%d0 |rounding precision in d0{10:9}
359 bfextu %d0{
360 cmpil
361 beql unff_sgl |force precision is single
362 cmpil
363 beql unff_dbl
364 movew CMDREG3B(%a6),%d0 |get the command word again
365 andil
366 cmpil
367 beql unf_fsgl |fsglmul or fsgldiv
368 cmpil
369 beql unf_fsgl |fsgldiv or fsglmul
370 bra unf_fpcr
371unf_e1_exc:
372 movel CMDREG1B(%a6),%d0 |get 32 bits off the stack, 1st 16 bits
373| ;are the command word
374 andil
375 cmpil
376 beql unff_sgl |force single
377 cmpil
378 beql unff_dbl
379 movel CMDREG1B(%a6),%d0 |get the command word again
380 andil
381 cmpil
382 beql unf_fsgl |fsglmul
383 cmpil
384 beql unf_fsgl |fsgldiv
385 bra unf_fpcr
386
387|
388| Convert to return format. The values from cmdreg3b and the return
389| values are:
390| cmdreg3b return precision
391| -------- ------ ---------
392| 00,01 0 ext
393| 10 1 sgl
394| 11 2 dbl
395| Force single
396|
397unff_sgl:
398 movel
399 rts
400|
401| Force double
402|
403unff_dbl:
404 movel
405 rts
406|
407| Force extended
408|
409unf_fsgl:
410 movel
411 rts
412|
413| Get rounding precision set in FPCR{7:6}.
414|
415unf_fpcr:
416 movel USER_FPCR(%a6),%d0 |rounding precision bits in d0{7:6}
417 bfextu %d0{
418 rts
419|
420| g_opcls --- put opclass in d0{2:0}
421|
422g_opcls:
423 btstb
424 beqs opc_1b |if set, go to cmdreg1b
425opc_3b:
426 clrl %d0 |if E3, only opclass 0x0 is possible
427 rts
428opc_1b:
429 movel CMDREG1B(%a6),%d0
430 bfextu %d0{
431 rts
432|
433| g_dfmtou --- put destination format in d0{1:0}
434|
435| If E1, the format is from cmdreg1b{12:10}
436| If E3, the format is extended.
437|
438| Dest. Fmt.
439| extended 010 -> 00
440| single 001 -> 01
441| double 101 -> 10
442|
443g_dfmtou:
444 btstb
445 beqs op011
446 clrl %d0 |if E1, size is always ext
447 rts
448op011:
449 movel CMDREG1B(%a6),%d0
450 bfextu %d0{
451 cmpb
452 bnes not_sgl
453 movel
454 rts
455not_sgl:
456 cmpb
457 bnes not_dbl
458 movel
459 rts
460not_dbl:
461 clrl %d0 |must be extended
462 rts
463
464|
465|
466| Final result table for unf_sub. Note that the negative counterparts
467| are unnecessary as unf_sub always returns the sign separately from
468| the exponent.
469| ;+zero
470EXT_PZRO: .long 0x00000000,0x00000000,0x00000000,0x00000000
471| ;+zero
472SGL_PZRO: .long 0x3f810000,0x00000000,0x00000000,0x00000000
473| ;+zero
474DBL_PZRO: .long 0x3c010000,0x00000000,0x00000000,0x00000000
475| ;smallest +ext denorm
476EXT_PSML: .long 0x00000000,0x00000000,0x00000001,0x00000000
477| ;smallest +sgl denorm
478SGL_PSML: .long 0x3f810000,0x00000100,0x00000000,0x00000000
479| ;smallest +dbl denorm
480DBL_PSML: .long 0x3c010000,0x00000000,0x00000800,0x00000000
481|
482| UNF_SUB --- underflow result calculation
483|
484| Input:
485| d0 contains round precision
486| a0 points to input operand in the internal extended format
487|
488| Output:
489| a0 points to correct internal extended precision result.
490|
491
492tblunf:
493 .long uEXT_RN
494 .long uEXT_RZ
495 .long uEXT_RM
496 .long uEXT_RP
497 .long uSGL_RN
498 .long uSGL_RZ
499 .long uSGL_RM
500 .long uSGL_RP
501 .long uDBL_RN
502 .long uDBL_RZ
503 .long uDBL_RM
504 .long uDBL_RP
505 .long uDBL_RN
506 .long uDBL_RZ
507 .long uDBL_RM
508 .long uDBL_RP
509
510 .global unf_sub
511unf_sub:
512 lsll
513 bfextu FPCR_MODE(%a6){
514 orl %d1,%d0 |index is fmt:mode in d0{3:0}
515 leal tblunf,%a1 |load a1 with table address
516 movel %a1@(%d0:l:4),%a1 |use d0 as index to the table
517 jmp (%a1) |go to the correct routine
518|
519|case DEST_FMT = EXT
520|
521uEXT_RN:
522 leal EXT_PZRO,%a1 |answer is +/- zero
523 bsetb
524 bra uset_sign |now go set the sign
525uEXT_RZ:
526 leal EXT_PZRO,%a1 |answer is +/- zero
527 bsetb
528 bra uset_sign |now go set the sign
529uEXT_RM:
530 tstb LOCAL_SGN(%a0) |if negative underflow
531 beqs ue_rm_pos
532ue_rm_neg:
533 leal EXT_PSML,%a1 |answer is negative smallest denorm
534 bsetb
535 bra end_unfr
536ue_rm_pos:
537 leal EXT_PZRO,%a1 |answer is positive zero
538 bsetb
539 bra end_unfr
540uEXT_RP:
541 tstb LOCAL_SGN(%a0) |if negative underflow
542 beqs ue_rp_pos
543ue_rp_neg:
544 leal EXT_PZRO,%a1 |answer is negative zero
545 oril
546 bra end_unfr
547ue_rp_pos:
548 leal EXT_PSML,%a1 |answer is positive smallest denorm
549 bra end_unfr
550|
551|case DEST_FMT = DBL
552|
553uDBL_RN:
554 leal DBL_PZRO,%a1 |answer is +/- zero
555 bsetb
556 bra uset_sign
557uDBL_RZ:
558 leal DBL_PZRO,%a1 |answer is +/- zero
559 bsetb
560 bra uset_sign |now go set the sign
561uDBL_RM:
562 tstb LOCAL_SGN(%a0) |if negative overflow
563 beqs ud_rm_pos
564ud_rm_neg:
565 leal DBL_PSML,%a1 |answer is smallest denormalized negative
566 bsetb
567 bra end_unfr
568ud_rm_pos:
569 leal DBL_PZRO,%a1 |answer is positive zero
570 bsetb
571 bra end_unfr
572uDBL_RP:
573 tstb LOCAL_SGN(%a0) |if negative overflow
574 beqs ud_rp_pos
575ud_rp_neg:
576 leal DBL_PZRO,%a1 |answer is negative zero
577 oril
578 bra end_unfr
579ud_rp_pos:
580 leal DBL_PSML,%a1 |answer is smallest denormalized negative
581 bra end_unfr
582|
583|case DEST_FMT = SGL
584|
585uSGL_RN:
586 leal SGL_PZRO,%a1 |answer is +/- zero
587 bsetb
588 bras uset_sign
589uSGL_RZ:
590 leal SGL_PZRO,%a1 |answer is +/- zero
591 bsetb
592 bras uset_sign
593uSGL_RM:
594 tstb LOCAL_SGN(%a0) |if negative overflow
595 beqs us_rm_pos
596us_rm_neg:
597 leal SGL_PSML,%a1 |answer is smallest denormalized negative
598 bsetb
599 bras end_unfr
600us_rm_pos:
601 leal SGL_PZRO,%a1 |answer is positive zero
602 bsetb
603 bras end_unfr
604uSGL_RP:
605 tstb LOCAL_SGN(%a0) |if negative overflow
606 beqs us_rp_pos
607us_rp_neg:
608 leal SGL_PZRO,%a1 |answer is negative zero
609 oril
610 bras end_unfr
611us_rp_pos:
612 leal SGL_PSML,%a1 |answer is smallest denormalized positive
613 bras end_unfr
614
615uset_sign:
616 tstb LOCAL_SGN(%a0) |if negative overflow
617 beqs end_unfr
618uneg_sign:
619 bsetb
620
621end_unfr:
622 movew LOCAL_EX(%a1),LOCAL_EX(%a0) |be careful not to overwrite sign
623 movel LOCAL_HI(%a1),LOCAL_HI(%a0)
624 movel LOCAL_LO(%a1),LOCAL_LO(%a0)
625 rts
626|
627| reg_dest --- write byte, word, or long data to Dn
628|
629|
630| Input:
631| L_SCR1: Data
632| d1: data size and dest register number formatted as:
633|
634| 32 5 4 3 2 1 0
635| -----------------------------------------------
636| | 0 | Size | Dest Reg
637| -----------------------------------------------
638|
639| Size is:
640| 0 - Byte
641| 1 - Word
642| 2 - Long/Single
643|
644pregdst:
645 .long byte_d0
646 .long byte_d1
647 .long byte_d2
648 .long byte_d3
649 .long byte_d4
650 .long byte_d5
651 .long byte_d6
652 .long byte_d7
653 .long word_d0
654 .long word_d1
655 .long word_d2
656 .long word_d3
657 .long word_d4
658 .long word_d5
659 .long word_d6
660 .long word_d7
661 .long long_d0
662 .long long_d1
663 .long long_d2
664 .long long_d3
665 .long long_d4
666 .long long_d5
667 .long long_d6
668 .long long_d7
669
670reg_dest:
671 leal pregdst,%a0
672 movel %a0@(%d1:l:4),%a0
673 jmp (%a0)
674
675byte_d0:
676 moveb L_SCR1(%a6),USER_D0+3(%a6)
677 rts
678byte_d1:
679 moveb L_SCR1(%a6),USER_D1+3(%a6)
680 rts
681byte_d2:
682 moveb L_SCR1(%a6),%d2
683 rts
684byte_d3:
685 moveb L_SCR1(%a6),%d3
686 rts
687byte_d4:
688 moveb L_SCR1(%a6),%d4
689 rts
690byte_d5:
691 moveb L_SCR1(%a6),%d5
692 rts
693byte_d6:
694 moveb L_SCR1(%a6),%d6
695 rts
696byte_d7:
697 moveb L_SCR1(%a6),%d7
698 rts
699word_d0:
700 movew L_SCR1(%a6),USER_D0+2(%a6)
701 rts
702word_d1:
703 movew L_SCR1(%a6),USER_D1+2(%a6)
704 rts
705word_d2:
706 movew L_SCR1(%a6),%d2
707 rts
708word_d3:
709 movew L_SCR1(%a6),%d3
710 rts
711word_d4:
712 movew L_SCR1(%a6),%d4
713 rts
714word_d5:
715 movew L_SCR1(%a6),%d5
716 rts
717word_d6:
718 movew L_SCR1(%a6),%d6
719 rts
720word_d7:
721 movew L_SCR1(%a6),%d7
722 rts
723long_d0:
724 movel L_SCR1(%a6),USER_D0(%a6)
725 rts
726long_d1:
727 movel L_SCR1(%a6),USER_D1(%a6)
728 rts
729long_d2:
730 movel L_SCR1(%a6),%d2
731 rts
732long_d3:
733 movel L_SCR1(%a6),%d3
734 rts
735long_d4:
736 movel L_SCR1(%a6),%d4
737 rts
738long_d5:
739 movel L_SCR1(%a6),%d5
740 rts
741long_d6:
742 movel L_SCR1(%a6),%d6
743 rts
744long_d7:
745 movel L_SCR1(%a6),%d7
746 rts
747 |end
748
