2 # $NetBSD: ilsp.s,v 1.1 2000/04/14 20:24:39 is Exp $
5 #~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
6 # MOTOROLA MICROPROCESSOR & MEMORY TECHNOLOGY GROUP
7 # M68000 Hi-Performance Microprocessor Division
8 # M68060 Software Package Production Release
10 # M68060 Software Package Copyright (C) 1993, 1994, 1995, 1996 Motorola Inc.
11 # All rights reserved.
13 # THE SOFTWARE is provided on an "AS IS" basis and without warranty.
14 # To the maximum extent permitted by applicable law,
15 # MOTOROLA DISCLAIMS ALL WARRANTIES WHETHER EXPRESS OR IMPLIED,
16 # INCLUDING IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS
17 # FOR A PARTICULAR PURPOSE and any warranty against infringement with
18 # regard to the SOFTWARE (INCLUDING ANY MODIFIED VERSIONS THEREOF)
19 # and any accompanying written materials.
21 # To the maximum extent permitted by applicable law,
22 # IN NO EVENT SHALL MOTOROLA BE LIABLE FOR ANY DAMAGES WHATSOEVER
23 # (INCLUDING WITHOUT LIMITATION, DAMAGES FOR LOSS OF BUSINESS PROFITS,
24 # BUSINESS INTERRUPTION, LOSS OF BUSINESS INFORMATION, OR OTHER PECUNIARY LOSS)
25 # ARISING OF THE USE OR INABILITY TO USE THE SOFTWARE.
27 # Motorola assumes no responsibility for the maintenance and support
30 # You are hereby granted a copyright license to use, modify, and distribute the
31 # SOFTWARE so long as this entire notice is retained without alteration
32 # in any modified and/or redistributed versions, and that such modified
33 # versions are clearly identified as such.
34 # No licenses are granted by implication, estoppel or otherwise under any
35 # patents or trademarks of Motorola, Inc.
36 #~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
40 # This file is appended to the top of the 060FPLSP package
41 # and contains the entry points into the package. The user, in
42 # effect, branches to one of the branch table entries located here.
45 bra.
l _060LSP__idivs64_
47 bra.
l _060LSP__idivu64_
50 bra.
l _060LSP__imuls64_
52 bra.
l _060LSP__imulu64_
55 bra.
l _060LSP__cmp2_Ab_
57 bra.
l _060LSP__cmp2_Aw_
59 bra.
l _060LSP__cmp2_Al_
61 bra.
l _060LSP__cmp2_Db_
63 bra.
l _060LSP__cmp2_Dw_
65 bra.
l _060LSP__cmp2_Dl_
68 # leave room for future possible aditions.
71 #########################################################################
72 # XDEF **************************************************************** #
73 # _060LSP__idivu64_(): Emulate 64-bit unsigned div instruction. #
74 # _060LSP__idivs64_(): Emulate 64-bit signed div instruction. #
76 # This is the library version which is accessed as a subroutine #
77 # and therefore does not work exactly like the 680X0 div{s,u}.l #
78 # 64-bit divide instruction. #
80 # XREF **************************************************************** #
83 # INPUT *************************************************************** #
85 # 0x8(sp) = hi(dividend) #
86 # 0xc(sp) = lo(dividend) #
87 # 0x10(sp) = pointer to location to place quotient/remainder #
89 # OUTPUT ************************************************************** #
90 # 0x10(sp) = points to location of remainder/quotient. #
91 # remainder is in first longword, quotient is in 2nd. #
93 # ALGORITHM *********************************************************** #
94 # If the operands are signed, make them unsigned and save the #
95 # sign info for later. Separate out special cases like divide-by-zero #
96 # or 32-bit divides if possible. Else, use a special math algorithm #
97 # to calculate the result. #
98 # Restore sign info if signed instruction. Set the condition #
99 # codes before performing the final "rts". If the divisor was equal to #
100 # zero, then perform a divide-by-zero using a 16-bit implemented #
101 # divide instruction. This way, the operating system can record that #
102 # the event occurred even though it may not point to the correct place. #
104 #########################################################################
117 global _060LSP__idivs64_
119 # PROLOGUE BEGIN ########################################################
121 movm.
l &0x3f00,-(%sp
) # save d2-d7
122 # fmovm.l &0x0,-(%sp) # save no fpregs
123 # PROLOGUE END ##########################################################
125 mov.w
%cc
,DIV64_CC
(%a6
)
126 st POSNEG
(%a6
) # signed operation
132 global _060LSP__idivu64_
134 # PROLOGUE BEGIN ########################################################
136 movm.
l &0x3f00,-(%sp
) # save d2-d7
137 # fmovm.l &0x0,-(%sp) # save no fpregs
138 # PROLOGUE END ##########################################################
140 mov.w
%cc
,DIV64_CC
(%a6
)
141 sf POSNEG
(%a6
) # unsigned operation
144 mov.
l 0x8(%a6
),%d7
# fetch divisor
146 beq.w ldiv64eq0
# divisor is = 0!!!
148 mov.
l 0xc(%a6
), %d5
# get dividend hi
149 mov.
l 0x10(%a6
), %d6
# get dividend lo
151 # separate signed and unsigned divide
152 tst.
b POSNEG
(%a6
) # signed or unsigned?
153 beq.
b ldspecialcases
# use positive divide
155 # save the sign of the divisor
156 # make divisor unsigned if it's negative
157 tst.
l %d7
# chk sign of divisor
158 slt NDIVISOR
(%a6
) # save sign of divisor
160 neg.l %d7
# complement negative divisor
162 # save the sign of the dividend
163 # make dividend unsigned if it's negative
165 tst.
l %d5
# chk sign of hi(dividend)
166 slt NDIVIDEND
(%a6
) # save sign of dividend
169 mov.w
&0x0, %cc
# clear 'X' cc bit
170 negx.
l %d6
# complement signed dividend
173 # extract some special cases:
174 # - is (dividend == 0) ?
175 # - is (hi(dividend) == 0 && (divisor <= lo(dividend))) ? (32-bit div)
177 tst.
l %d5
# is (hi(dividend) == 0)
178 bne.
b ldnormaldivide
# no, so try it the long way
180 tst.
l %d6
# is (lo(dividend) == 0), too
181 beq.w lddone
# yes, so (dividend == 0)
183 cmp.
l %d7
,%d6
# is (divisor <= lo(dividend))
184 bls.
b ld32bitdivide
# yes, so use 32 bit divide
186 exg
%d5
,%d6
# q = 0, r = dividend
187 bra.w ldivfinish
# can't divide, we're done.
190 tdivu.
l %d7
, %d5
:%d6
# it's only a 32/32 bit div!
196 # - is hi(dividend) >= divisor ? if yes, then overflow
198 bls.
b lddovf
# answer won't fit in 32 bits
200 # perform the divide algorithm:
201 bsr.
l ldclassical
# do int divide
203 # separate into signed and unsigned finishes.
205 tst.
b POSNEG
(%a6
) # do divs, divu separately
206 beq.
b lddone
# divu has no processing!!!
208 # it was a divs.l, so ccode setting is a little more complicated...
209 tst.
b NDIVIDEND
(%a6
) # remainder has same sign
210 beq.
b ldcc
# as dividend.
211 neg.l %d5
# sgn(rem) = sgn(dividend)
213 mov.
b NDIVISOR
(%a6
), %d0
214 eor.
b %d0
, NDIVIDEND
(%a6
) # chk if quotient is negative
215 beq.
b ldqpos
# branch to quot positive
217 # 0x80000000 is the largest number representable as a 32-bit negative
218 # number. the negative of 0x80000000 is 0x80000000.
219 cmpi.
l %d6
, &0x80000000 # will (-quot) fit in 32 bits?
222 neg.l %d6
# make (-quot) 2's comp
227 btst
&0x1f, %d6
# will (+quot) fit in 32 bits?
231 # if the register numbers are the same, only the quotient gets saved.
232 # so, if we always save the quotient second, we save ourselves a cmp&beq
233 andi.w
&0x10,DIV64_CC
(%a6
)
234 mov.w DIV64_CC
(%a6
),%cc
235 tst.
l %d6
# may set 'N' ccode bit
237 # here, the result is in d1 and d0. the current strategy is to save
238 # the values at the location pointed to by a0.
239 # use movm here to not disturb the condition codes.
241 movm.
l &0x0060,([0x14,%a6
]) # save result
243 # EPILOGUE BEGIN ########################################################
244 # fmovm.l (%sp)+,&0x0 # restore no fpregs
245 movm.
l (%sp
)+,&0x00fc # restore d2-d7
247 # EPILOGUE END ##########################################################
251 # the result should be the unchanged dividend
253 mov.
l 0xc(%a6
), %d5
# get dividend hi
254 mov.
l 0x10(%a6
), %d6
# get dividend lo
256 andi.w
&0x1c,DIV64_CC
(%a6
)
257 ori.w
&0x02,DIV64_CC
(%a6
) # set 'V' ccode bit
258 mov.w DIV64_CC
(%a6
),%cc
263 mov.
l 0xc(%a6
),([0x14,%a6
])
264 mov.
l 0x10(%a6
),([0x14,%a6
],0x4)
266 mov.w DIV64_CC
(%a6
),%cc
268 # EPILOGUE BEGIN ########################################################
269 # fmovm.l (%sp)+,&0x0 # restore no fpregs
270 movm.
l (%sp
)+,&0x00fc # restore d2-d7
272 # EPILOGUE END ##########################################################
274 divu.w
&0x0,%d0
# force a divbyzero exception
277 ###########################################################################
278 #########################################################################
279 # This routine uses the 'classical' Algorithm D from Donald Knuth's #
280 # Art of Computer Programming, vol II, Seminumerical Algorithms. #
281 # For this implementation b=2**16, and the target is U1U2U3U4/V1V2, #
282 # where U,V are words of the quadword dividend and longword divisor, #
283 # and U1, V1 are the most significant words. #
285 # The most sig. longword of the 64 bit dividend must be in %d5, least #
286 # in %d6. The divisor must be in the variable ddivisor, and the #
287 # signed/unsigned flag ddusign must be set (0=unsigned,1=signed). #
288 # The quotient is returned in %d6, remainder in %d5, unless the #
289 # v (overflow) bit is set in the saved %ccr. If overflow, the dividend #
291 #########################################################################
293 # if the divisor msw is 0, use simpler algorithm then the full blown
297 bhi.
b lddknuth
# go use D. Knuth algorithm
299 # Since the divisor is only a word (and larger than the mslw of the dividend),
300 # a simpler algorithm may be used :
301 # In the general case, four quotient words would be created by
302 # dividing the divisor word into each dividend word. In this case,
303 # the first two quotient words must be zero, or overflow would occur.
304 # Since we already checked this case above, we can treat the most significant
305 # longword of the dividend as (0) remainder (see Knuth) and merely complete
306 # the last two divisions to get a quotient longword and word remainder:
309 swap
%d5
# same as r*b if previous step rqd
310 swap
%d6
# get u3 to lsw position
311 mov.w
%d6
, %d5
# rb + u3
315 mov.w
%d5
, %d1
# first quotient word
317 mov.w
%d6
, %d5
# rb + u4
322 mov.w
%d5
, %d1
# 2nd quotient 'digit'
324 swap
%d5
# now remainder
325 mov.
l %d1
, %d6
# and quotient
330 # In this algorithm, the divisor is treated as a 2 digit (word) number
331 # which is divided into a 3 digit (word) dividend to get one quotient
332 # digit (word). After subtraction, the dividend is shifted and the
333 # process repeated. Before beginning, the divisor and quotient are
334 # 'normalized' so that the process of estimating the quotient digit
335 # will yield verifiably correct results..
337 clr.
l DDNORMAL
(%a6
) # count of shifts for normalization
338 clr.
b DDSECOND
(%a6
) # clear flag for quotient digits
339 clr.
l %d1
# %d1 will hold trial quotient
341 btst
&31, %d7
# must we normalize? first word of
342 bne.
b lddnormalized
# divisor (V1) must be >= 65536/2
343 addq.
l &0x1, DDNORMAL
(%a6
) # count normalization shifts
344 lsl.
l &0x1, %d7
# shift the divisor
345 lsl.
l &0x1, %d6
# shift u4,u3 with overflow to u2
346 roxl.
l &0x1, %d5
# shift u1,u2
350 # Now calculate an estimate of the quotient words (msw first, then lsw).
351 # The comments use subscripts for the first quotient digit determination.
352 mov.
l %d7
, %d3
# divisor
353 mov.
l %d5
, %d2
# dividend mslw
356 cmp.w
%d2
, %d3
# V1 = U1 ?
358 mov.w
&0xffff, %d1
# use max trial quotient word
363 divu.w
%d3
, %d1
# use quotient of mslw/msw
365 andi.l &0x0000ffff, %d1
# zero any remainder
368 # now test the trial quotient and adjust. This step plus the
369 # normalization assures (according to Knuth) that the trial
370 # quotient will be at worst 1 too large.
372 clr.w
%d6
# word u3 left
373 swap
%d6
# in lsw position
374 lddadj1
: mov.
l %d7
, %d3
376 mulu.w
%d7
, %d2
# V2q
378 mulu.w
%d1
, %d3
# V1q
379 mov.
l %d5
, %d4
# U1U2
380 sub.l %d3
, %d4
# U1U2 - V1q
385 mov.w
%d6
,%d4
# insert lower word (U3)
387 tst.w
%d0
# is upper word set?
390 # add.l %d6, %d4 # (U1U2 - V1q) + U3
393 bls.
b lddadjd1
# is V2q > (U1U2-V1q) + U3 ?
394 subq.
l &0x1, %d1
# yes, decrement and recheck
397 # now test the word by multiplying it by the divisor (V1V2) and comparing
398 # the 3 digit (word) result with the current dividend words
399 mov.
l %d5
, -(%sp
) # save %d5 (%d6 already saved)
401 swap
%d6
# shift answer to ms 3 words
404 mov.
l %d5
, %d2
# now %d2,%d3 are trial*divisor
406 mov.
l (%sp
)+, %d5
# restore dividend
409 subx.
l %d2
, %d5
# subtract double precision
410 bcc ldd2nd
# no carry, do next quotient digit
411 subq.
l &0x1, %d1
# q is one too large
412 # need to add back divisor longword to current ms 3 digits of dividend
413 # - according to Knuth, this is done only 2 out of 65536 times for random
414 # divisor, dividend selection.
418 clr.w
%d3
# %d3 now ls word of divisor
419 add.l %d3
, %d6
# aligned with 3rd word of dividend
422 clr.w
%d3
# %d3 now ms word of divisor
423 swap
%d3
# aligned with 2nd word of dividend
426 tst.
b DDSECOND
(%a6
) # both q words done?
428 # first quotient digit now correct. store digit and shift the
429 # (subtracted) dividend
430 mov.w
%d1
, DDQUOTIENT
(%a6
)
436 st DDSECOND
(%a6
) # second digit
439 # add 2nd word to quotient, get the remainder.
440 mov.w
%d1
, DDQUOTIENT+
2(%a6
)
441 # shift down one word/digit to renormalize remainder.
445 mov.
l DDNORMAL
(%a6
), %d7
# get norm shift count
447 subq.
l &0x1, %d7
# set for loop count
449 lsr.
l &0x1, %d5
# shift into %d6
453 mov.
l %d6
, %d5
# remainder
454 mov.
l DDQUOTIENT
(%a6
), %d6
# quotient
458 # factors for the 32X32->64 multiplication are in %d5 and %d6.
459 # returns 64 bit result in %d5 (hi) %d6(lo).
460 # destroys %d2,%d3,%d4.
462 # multiply hi,lo words of each factor to get 4 intermediate products
468 mulu.w
%d5
, %d6
# %d6 <- lsw*lsw
469 mulu.w
%d3
, %d5
# %d5 <- msw-dest*lsw-source
470 mulu.w
%d4
, %d2
# %d2 <- msw-source*lsw-dest
471 mulu.w
%d4
, %d3
# %d3 <- msw*msw
472 # now use swap and addx to consolidate to two longwords
475 add.w
%d5
, %d6
# add msw of l*l to lsw of m*l product
476 addx.w
%d4
, %d3
# add any carry to m*m product
477 add.w
%d2
, %d6
# add in lsw of other m*l product
478 addx.w
%d4
, %d3
# add any carry to m*m product
479 swap
%d6
# %d6 is low 32 bits of final product
481 clr.w
%d2
# lsw of two mixed products used,
482 swap
%d5
# now use msws of longwords
485 add.l %d3
, %d5
# %d5 now ms 32 bits of final product
488 #########################################################################
489 # XDEF **************************************************************** #
490 # _060LSP__imulu64_(): Emulate 64-bit unsigned mul instruction #
491 # _060LSP__imuls64_(): Emulate 64-bit signed mul instruction. #
493 # This is the library version which is accessed as a subroutine #
494 # and therefore does not work exactly like the 680X0 mul{s,u}.l #
495 # 64-bit multiply instruction. #
497 # XREF **************************************************************** #
500 # INPUT *************************************************************** #
501 # 0x4(sp) = multiplier #
502 # 0x8(sp) = multiplicand #
503 # 0xc(sp) = pointer to location to place 64-bit result #
505 # OUTPUT ************************************************************** #
506 # 0xc(sp) = points to location of 64-bit result #
508 # ALGORITHM *********************************************************** #
509 # Perform the multiply in pieces using 16x16->32 unsigned #
510 # multiplies and "add" instructions. #
511 # Set the condition codes as appropriate before performing an #
514 #########################################################################
518 global _060LSP__imulu64_
521 # PROLOGUE BEGIN ########################################################
523 movm.
l &0x3800,-(%sp
) # save d2-d4
524 # fmovm.l &0x0,-(%sp) # save no fpregs
525 # PROLOGUE END ##########################################################
527 mov.w
%cc
,MUL64_CC
(%a6
) # save incomming ccodes
529 mov.
l 0x8(%a6
),%d0
# store multiplier in d0
530 beq.w mulu64_zero
# handle zero separately
532 mov.
l 0xc(%a6
),%d1
# get multiplicand in d1
533 beq.w mulu64_zero
# handle zero separately
535 #########################################################################
537 # ---------------------------- #
538 # | hi(mplier) * hi(mplicand)| #
539 # ---------------------------- #
540 # ----------------------------- #
541 # | hi(mplier) * lo(mplicand) | #
542 # ----------------------------- #
543 # ----------------------------- #
544 # | lo(mplier) * hi(mplicand) | #
545 # ----------------------------- #
546 # | ----------------------------- #
547 # --|-- | lo(mplier) * lo(mplicand) | #
548 # | ----------------------------- #
549 # ======================================================== #
550 # -------------------------------------------------------- #
551 # | hi(result) | lo(result) | #
552 # -------------------------------------------------------- #
553 #########################################################################
555 # load temp registers with operands
556 mov.
l %d0
,%d2
# mr in d2
557 mov.
l %d0
,%d3
# mr in d3
558 mov.
l %d1
,%d4
# md in d4
559 swap
%d3
# hi(mr) in lo d3
560 swap
%d4
# hi(md) in lo d4
562 # complete necessary multiplies:
563 mulu.w
%d1
,%d0
# [1] lo(mr) * lo(md)
564 mulu.w
%d3
,%d1
# [2] hi(mr) * lo(md)
565 mulu.w
%d4
,%d2
# [3] lo(mr) * hi(md)
566 mulu.w
%d4
,%d3
# [4] hi(mr) * hi(md)
568 # add lo portions of [2],[3] to hi portion of [1].
569 # add carries produced from these adds to [4].
570 # lo([1]) is the final lo 16 bits of the result.
571 clr.
l %d4
# load d4 w/ zero value
572 swap
%d0
# hi([1]) <==> lo([1])
573 add.w
%d1
,%d0
# hi([1]) + lo([2])
574 addx.
l %d4
,%d3
# [4] + carry
575 add.w
%d2
,%d0
# hi([1]) + lo([3])
576 addx.
l %d4
,%d3
# [4] + carry
577 swap
%d0
# lo([1]) <==> hi([1])
579 # lo portions of [2],[3] have been added in to final result.
580 # now, clear lo, put hi in lo reg, and add to [4]
581 clr.w
%d1
# clear lo([2])
582 clr.w
%d2
# clear hi([3])
583 swap
%d1
# hi([2]) in lo d1
584 swap
%d2
# hi([3]) in lo d2
585 add.l %d2
,%d1
# [4] + hi([2])
586 add.l %d3
,%d1
# [4] + hi([3])
588 # now, grab the condition codes. only one that can be set is 'N'.
589 # 'N' CAN be set if the operation is unsigned if bit 63 is set.
590 mov.w MUL64_CC
(%a6
),%d4
591 andi.b &0x10,%d4
# keep old 'X' bit
592 tst.
l %d1
# may set 'N' bit
594 ori.
b &0x8,%d4
# set 'N' bit
598 # here, the result is in d1 and d0. the current strategy is to save
599 # the values at the location pointed to by a0.
600 # use movm here to not disturb the condition codes.
603 movm.
l &0x0003,([0x10,%a6
]) # save result
605 # EPILOGUE BEGIN ########################################################
606 # fmovm.l (%sp)+,&0x0 # restore no fpregs
607 movm.
l (%sp
)+,&0x001c # restore d2-d4
609 # EPILOGUE END ##########################################################
613 # one or both of the operands is zero so the result is also zero.
614 # save the zero result to the register file and set the 'Z' ccode bit.
619 mov.w MUL64_CC
(%a6
),%d4
622 mov.w
%d4
,%cc
# set 'Z' ccode bit
629 global _060LSP__imuls64_
632 # PROLOGUE BEGIN ########################################################
634 movm.
l &0x3c00,-(%sp
) # save d2-d5
635 # fmovm.l &0x0,-(%sp) # save no fpregs
636 # PROLOGUE END ##########################################################
638 mov.w
%cc
,MUL64_CC
(%a6
) # save incomming ccodes
640 mov.
l 0x8(%a6
),%d0
# store multiplier in d0
641 beq.
b mulu64_zero
# handle zero separately
643 mov.
l 0xc(%a6
),%d1
# get multiplicand in d1
644 beq.
b mulu64_zero
# handle zero separately
646 clr.
b %d5
# clear sign tag
647 tst.
l %d0
# is multiplier negative?
648 bge.
b muls64_chk_md_sgn
# no
649 neg.l %d0
# make multiplier positive
651 ori.
b &0x1,%d5
# save multiplier sgn
653 # the result sign is the exclusive or of the operand sign bits.
655 tst.
l %d1
# is multiplicand negative?
656 bge.
b muls64_alg
# no
657 neg.l %d1
# make multiplicand positive
659 eori.
b &0x1,%d5
# calculate correct sign
661 #########################################################################
663 # ---------------------------- #
664 # | hi(mplier) * hi(mplicand)| #
665 # ---------------------------- #
666 # ----------------------------- #
667 # | hi(mplier) * lo(mplicand) | #
668 # ----------------------------- #
669 # ----------------------------- #
670 # | lo(mplier) * hi(mplicand) | #
671 # ----------------------------- #
672 # | ----------------------------- #
673 # --|-- | lo(mplier) * lo(mplicand) | #
674 # | ----------------------------- #
675 # ======================================================== #
676 # -------------------------------------------------------- #
677 # | hi(result) | lo(result) | #
678 # -------------------------------------------------------- #
679 #########################################################################
681 # load temp registers with operands
682 mov.
l %d0
,%d2
# mr in d2
683 mov.
l %d0
,%d3
# mr in d3
684 mov.
l %d1
,%d4
# md in d4
685 swap
%d3
# hi(mr) in lo d3
686 swap
%d4
# hi(md) in lo d4
688 # complete necessary multiplies:
689 mulu.w
%d1
,%d0
# [1] lo(mr) * lo(md)
690 mulu.w
%d3
,%d1
# [2] hi(mr) * lo(md)
691 mulu.w
%d4
,%d2
# [3] lo(mr) * hi(md)
692 mulu.w
%d4
,%d3
# [4] hi(mr) * hi(md)
694 # add lo portions of [2],[3] to hi portion of [1].
695 # add carries produced from these adds to [4].
696 # lo([1]) is the final lo 16 bits of the result.
697 clr.
l %d4
# load d4 w/ zero value
698 swap
%d0
# hi([1]) <==> lo([1])
699 add.w
%d1
,%d0
# hi([1]) + lo([2])
700 addx.
l %d4
,%d3
# [4] + carry
701 add.w
%d2
,%d0
# hi([1]) + lo([3])
702 addx.
l %d4
,%d3
# [4] + carry
703 swap
%d0
# lo([1]) <==> hi([1])
705 # lo portions of [2],[3] have been added in to final result.
706 # now, clear lo, put hi in lo reg, and add to [4]
707 clr.w
%d1
# clear lo([2])
708 clr.w
%d2
# clear hi([3])
709 swap
%d1
# hi([2]) in lo d1
710 swap
%d2
# hi([3]) in lo d2
711 add.l %d2
,%d1
# [4] + hi([2])
712 add.l %d3
,%d1
# [4] + hi([3])
714 tst.
b %d5
# should result be signed?
715 beq.
b muls64_done
# no
717 # result should be a signed negative number.
718 # compute 2's complement of the unsigned number:
719 # -negate all bits and add 1
721 not.l %d0
# negate lo(result) bits
722 not.l %d1
# negate hi(result) bits
723 addq.
l &1,%d0
# add 1 to lo(result)
724 addx.
l %d4
,%d1
# add carry to hi(result)
727 mov.w MUL64_CC
(%a6
),%d4
728 andi.b &0x10,%d4
# keep old 'X' bit
729 tst.
l %d1
# may set 'N' bit
731 ori.
b &0x8,%d4
# set 'N' bit
735 # here, the result is in d1 and d0. the current strategy is to save
736 # the values at the location pointed to by a0.
737 # use movm here to not disturb the condition codes.
740 movm.
l &0x0003,([0x10,%a6
]) # save result at (a0)
742 # EPILOGUE BEGIN ########################################################
743 # fmovm.l (%sp)+,&0x0 # restore no fpregs
744 movm.
l (%sp
)+,&0x003c # restore d2-d5
746 # EPILOGUE END ##########################################################
750 # one or both of the operands is zero so the result is also zero.
751 # save the zero result to the register file and set the 'Z' ccode bit.
756 mov.w MUL64_CC
(%a6
),%d4
759 mov.w
%d4
,%cc
# set 'Z' ccode bit
763 #########################################################################
764 # XDEF **************************************************************** #
765 # _060LSP__cmp2_Ab_(): Emulate "cmp2.b An,<ea>". #
766 # _060LSP__cmp2_Aw_(): Emulate "cmp2.w An,<ea>". #
767 # _060LSP__cmp2_Al_(): Emulate "cmp2.l An,<ea>". #
768 # _060LSP__cmp2_Db_(): Emulate "cmp2.b Dn,<ea>". #
769 # _060LSP__cmp2_Dw_(): Emulate "cmp2.w Dn,<ea>". #
770 # _060LSP__cmp2_Dl_(): Emulate "cmp2.l Dn,<ea>". #
772 # This is the library version which is accessed as a subroutine #
773 # and therefore does not work exactly like the 680X0 "cmp2" #
776 # XREF **************************************************************** #
779 # INPUT *************************************************************** #
781 # 0x8(sp) = pointer to boundary pair #
783 # OUTPUT ************************************************************** #
784 # cc = condition codes are set correctly #
786 # ALGORITHM *********************************************************** #
787 # In the interest of simplicity, all operands are converted to #
788 # longword size whether the operation is byte, word, or long. The #
789 # bounds are sign extended accordingly. If Rn is a data regsiter, Rn is #
790 # also sign extended. If Rn is an address register, it need not be sign #
791 # extended since the full register is always used. #
792 # The condition codes are set correctly before the final "rts". #
794 #########################################################################
798 global _060LSP__cmp2_Ab_
801 # PROLOGUE BEGIN ########################################################
803 movm.
l &0x3800,-(%sp
) # save d2-d4
804 # fmovm.l &0x0,-(%sp) # save no fpregs
805 # PROLOGUE END ##########################################################
807 mov.w
%cc
,CMP2_CC
(%a6
)
808 mov.
l 0x8(%a6
), %d2
# get regval
810 mov.
b ([0xc,%a6
],0x0),%d0
811 mov.
b ([0xc,%a6
],0x1),%d1
813 extb.
l %d0
# sign extend lo bnd
814 extb.
l %d1
# sign extend hi bnd
815 bra.w l_cmp2_cmp
# go do the compare emulation
817 global _060LSP__cmp2_Aw_
820 # PROLOGUE BEGIN ########################################################
822 movm.
l &0x3800,-(%sp
) # save d2-d4
823 # fmovm.l &0x0,-(%sp) # save no fpregs
824 # PROLOGUE END ##########################################################
826 mov.w
%cc
,CMP2_CC
(%a6
)
827 mov.
l 0x8(%a6
), %d2
# get regval
829 mov.w
([0xc,%a6
],0x0),%d0
830 mov.w
([0xc,%a6
],0x2),%d1
832 ext.
l %d0
# sign extend lo bnd
833 ext.
l %d1
# sign extend hi bnd
834 bra.w l_cmp2_cmp
# go do the compare emulation
836 global _060LSP__cmp2_Al_
839 # PROLOGUE BEGIN ########################################################
841 movm.
l &0x3800,-(%sp
) # save d2-d4
842 # fmovm.l &0x0,-(%sp) # save no fpregs
843 # PROLOGUE END ##########################################################
845 mov.w
%cc
,CMP2_CC
(%a6
)
846 mov.
l 0x8(%a6
), %d2
# get regval
848 mov.
l ([0xc,%a6
],0x0),%d0
849 mov.
l ([0xc,%a6
],0x4),%d1
850 bra.w l_cmp2_cmp
# go do the compare emulation
852 global _060LSP__cmp2_Db_
855 # PROLOGUE BEGIN ########################################################
857 movm.
l &0x3800,-(%sp
) # save d2-d4
858 # fmovm.l &0x0,-(%sp) # save no fpregs
859 # PROLOGUE END ##########################################################
861 mov.w
%cc
,CMP2_CC
(%a6
)
862 mov.
l 0x8(%a6
), %d2
# get regval
864 mov.
b ([0xc,%a6
],0x0),%d0
865 mov.
b ([0xc,%a6
],0x1),%d1
867 extb.
l %d0
# sign extend lo bnd
868 extb.
l %d1
# sign extend hi bnd
870 # operation is a data register compare.
871 # sign extend byte to long so we can do simple longword compares.
872 extb.
l %d2
# sign extend data byte
873 bra.w l_cmp2_cmp
# go do the compare emulation
875 global _060LSP__cmp2_Dw_
878 # PROLOGUE BEGIN ########################################################
880 movm.
l &0x3800,-(%sp
) # save d2-d4
881 # fmovm.l &0x0,-(%sp) # save no fpregs
882 # PROLOGUE END ##########################################################
884 mov.w
%cc
,CMP2_CC
(%a6
)
885 mov.
l 0x8(%a6
), %d2
# get regval
887 mov.w
([0xc,%a6
],0x0),%d0
888 mov.w
([0xc,%a6
],0x2),%d1
890 ext.
l %d0
# sign extend lo bnd
891 ext.
l %d1
# sign extend hi bnd
893 # operation is a data register compare.
894 # sign extend word to long so we can do simple longword compares.
895 ext.
l %d2
# sign extend data word
896 bra.w l_cmp2_cmp
# go emulate compare
898 global _060LSP__cmp2_Dl_
901 # PROLOGUE BEGIN ########################################################
903 movm.
l &0x3800,-(%sp
) # save d2-d4
904 # fmovm.l &0x0,-(%sp) # save no fpregs
905 # PROLOGUE END ##########################################################
907 mov.w
%cc
,CMP2_CC
(%a6
)
908 mov.
l 0x8(%a6
), %d2
# get regval
910 mov.
l ([0xc,%a6
],0x0),%d0
911 mov.
l ([0xc,%a6
],0x4),%d1
914 # To set the ccodes correctly:
915 # (1) save 'Z' bit from (Rn - lo)
916 # (2) save 'Z' and 'N' bits from ((hi - lo) - (Rn - hi))
917 # (3) keep 'X', 'N', and 'V' from before instruction
921 sub.l %d0
, %d2
# (Rn - lo)
922 mov.w
%cc
, %d3
# fetch resulting ccodes
923 andi.b &0x4, %d3
# keep 'Z' bit
924 sub.l %d0
, %d1
# (hi - lo)
925 cmp.
l %d1
,%d2
# ((hi - lo) - (Rn - hi))
927 mov.w
%cc
, %d4
# fetch resulting ccodes
928 or.b %d4
, %d3
# combine w/ earlier ccodes
929 andi.b &0x5, %d3
# keep 'Z' and 'N'
931 mov.w CMP2_CC
(%a6
), %d4
# fetch old ccodes
932 andi.b &0x1a, %d4
# keep 'X','N','V' bits
933 or.b %d3
, %d4
# insert new ccodes
934 mov.w
%d4
,%cc
# save new ccodes
936 # EPILOGUE BEGIN ########################################################
937 # fmovm.l (%sp)+,&0x0 # restore no fpregs
938 movm.
l (%sp
)+,&0x001c # restore d2-d4
940 # EPILOGUE END ##########################################################