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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/m68k/ifpsp060/src/ilsp.S
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
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+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+MOTOROLA MICROPROCESSOR & MEMORY TECHNOLOGY GROUP
+M68000 Hi-Performance Microprocessor Division
+M68060 Software Package
+Production Release P1.00 -- October 10, 1994
+
+M68060 Software Package Copyright 1993, 1994 Motorola Inc. All rights reserved.
+
+THE SOFTWARE is provided on an "AS IS" basis and without warranty.
+To the maximum extent permitted by applicable law,
+MOTOROLA DISCLAIMS ALL WARRANTIES WHETHER EXPRESS OR IMPLIED,
+INCLUDING IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE
+and any warranty against infringement with regard to the SOFTWARE
+(INCLUDING ANY MODIFIED VERSIONS THEREOF) and any accompanying written materials.
+
+To the maximum extent permitted by applicable law,
+IN NO EVENT SHALL MOTOROLA BE LIABLE FOR ANY DAMAGES WHATSOEVER
+(INCLUDING WITHOUT LIMITATION, DAMAGES FOR LOSS OF BUSINESS PROFITS,
+BUSINESS INTERRUPTION, LOSS OF BUSINESS INFORMATION, OR OTHER PECUNIARY LOSS)
+ARISING OF THE USE OR INABILITY TO USE THE SOFTWARE.
+Motorola assumes no responsibility for the maintenance and support of the SOFTWARE.
+
+You are hereby granted a copyright license to use, modify, and distribute the SOFTWARE
+so long as this entire notice is retained without alteration in any modified and/or
+redistributed versions, and that such modified versions are clearly identified as such.
+No licenses are granted by implication, estoppel or otherwise under any patents
+or trademarks of Motorola, Inc.
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+# litop.s:
+# This file is appended to the top of the 060FPLSP package
+# and contains the entry points into the package. The user, in
+# effect, branches to one of the branch table entries located here.
+#
+
+ bra.l _060LSP__idivs64_
+ short 0x0000
+ bra.l _060LSP__idivu64_
+ short 0x0000
+
+ bra.l _060LSP__imuls64_
+ short 0x0000
+ bra.l _060LSP__imulu64_
+ short 0x0000
+
+ bra.l _060LSP__cmp2_Ab_
+ short 0x0000
+ bra.l _060LSP__cmp2_Aw_
+ short 0x0000
+ bra.l _060LSP__cmp2_Al_
+ short 0x0000
+ bra.l _060LSP__cmp2_Db_
+ short 0x0000
+ bra.l _060LSP__cmp2_Dw_
+ short 0x0000
+ bra.l _060LSP__cmp2_Dl_
+ short 0x0000
+
+# leave room for future possible aditions.
+ align 0x200
+
+#########################################################################
+# XDEF **************************************************************** #
+# _060LSP__idivu64_(): Emulate 64-bit unsigned div instruction. #
+# _060LSP__idivs64_(): Emulate 64-bit signed div instruction. #
+# #
+# This is the library version which is accessed as a subroutine #
+# and therefore does not work exactly like the 680X0 div{s,u}.l #
+# 64-bit divide instruction. #
+# #
+# XREF **************************************************************** #
+# None. #
+# #
+# INPUT *************************************************************** #
+# 0x4(sp) = divisor #
+# 0x8(sp) = hi(dividend) #
+# 0xc(sp) = lo(dividend) #
+# 0x10(sp) = pointer to location to place quotient/remainder #
+# #
+# OUTPUT ************************************************************** #
+# 0x10(sp) = points to location of remainder/quotient. #
+# remainder is in first longword, quotient is in 2nd. #
+# #
+# ALGORITHM *********************************************************** #
+# If the operands are signed, make them unsigned and save the #
+# sign info for later. Separate out special cases like divide-by-zero #
+# or 32-bit divides if possible. Else, use a special math algorithm #
+# to calculate the result. #
+# Restore sign info if signed instruction. Set the condition #
+# codes before performing the final "rts". If the divisor was equal to #
+# zero, then perform a divide-by-zero using a 16-bit implemented #
+# divide instruction. This way, the operating system can record that #
+# the event occurred even though it may not point to the correct place. #
+# #
+#########################################################################
+
+set POSNEG, -1
+set NDIVISOR, -2
+set NDIVIDEND, -3
+set DDSECOND, -4
+set DDNORMAL, -8
+set DDQUOTIENT, -12
+set DIV64_CC, -16
+
+##########
+# divs.l #
+##########
+ global _060LSP__idivs64_
+_060LSP__idivs64_:
+# PROLOGUE BEGIN ########################################################
+ link.w %a6,&-16
+ movm.l &0x3f00,-(%sp) # save d2-d7
+# fmovm.l &0x0,-(%sp) # save no fpregs
+# PROLOGUE END ##########################################################
+
+ mov.w %cc,DIV64_CC(%a6)
+ st POSNEG(%a6) # signed operation
+ bra.b ldiv64_cont
+
+##########
+# divu.l #
+##########
+ global _060LSP__idivu64_
+_060LSP__idivu64_:
+# PROLOGUE BEGIN ########################################################
+ link.w %a6,&-16
+ movm.l &0x3f00,-(%sp) # save d2-d7
+# fmovm.l &0x0,-(%sp) # save no fpregs
+# PROLOGUE END ##########################################################
+
+ mov.w %cc,DIV64_CC(%a6)
+ sf POSNEG(%a6) # unsigned operation
+
+ldiv64_cont:
+ mov.l 0x8(%a6),%d7 # fetch divisor
+
+ beq.w ldiv64eq0 # divisor is = 0!!!
+
+ mov.l 0xc(%a6), %d5 # get dividend hi
+ mov.l 0x10(%a6), %d6 # get dividend lo
+
+# separate signed and unsigned divide
+ tst.b POSNEG(%a6) # signed or unsigned?
+ beq.b ldspecialcases # use positive divide
+
+# save the sign of the divisor
+# make divisor unsigned if it's negative
+ tst.l %d7 # chk sign of divisor
+ slt NDIVISOR(%a6) # save sign of divisor
+ bpl.b ldsgndividend
+ neg.l %d7 # complement negative divisor
+
+# save the sign of the dividend
+# make dividend unsigned if it's negative
+ldsgndividend:
+ tst.l %d5 # chk sign of hi(dividend)
+ slt NDIVIDEND(%a6) # save sign of dividend
+ bpl.b ldspecialcases
+
+ mov.w &0x0, %cc # clear 'X' cc bit
+ negx.l %d6 # complement signed dividend
+ negx.l %d5
+
+# extract some special cases:
+# - is (dividend == 0) ?
+# - is (hi(dividend) == 0 && (divisor <= lo(dividend))) ? (32-bit div)
+ldspecialcases:
+ tst.l %d5 # is (hi(dividend) == 0)
+ bne.b ldnormaldivide # no, so try it the long way
+
+ tst.l %d6 # is (lo(dividend) == 0), too
+ beq.w lddone # yes, so (dividend == 0)
+
+ cmp.l %d7,%d6 # is (divisor <= lo(dividend))
+ bls.b ld32bitdivide # yes, so use 32 bit divide
+
+ exg %d5,%d6 # q = 0, r = dividend
+ bra.w ldivfinish # can't divide, we're done.
+
+ld32bitdivide:
+ tdivu.l %d7, %d5:%d6 # it's only a 32/32 bit div!
+
+ bra.b ldivfinish
+
+ldnormaldivide:
+# last special case:
+# - is hi(dividend) >= divisor ? if yes, then overflow
+ cmp.l %d7,%d5
+ bls.b lddovf # answer won't fit in 32 bits
+
+# perform the divide algorithm:
+ bsr.l ldclassical # do int divide
+
+# separate into signed and unsigned finishes.
+ldivfinish:
+ tst.b POSNEG(%a6) # do divs, divu separately
+ beq.b lddone # divu has no processing!!!
+
+# it was a divs.l, so ccode setting is a little more complicated...
+ tst.b NDIVIDEND(%a6) # remainder has same sign
+ beq.b ldcc # as dividend.
+ neg.l %d5 # sgn(rem) = sgn(dividend)
+ldcc:
+ mov.b NDIVISOR(%a6), %d0
+ eor.b %d0, NDIVIDEND(%a6) # chk if quotient is negative
+ beq.b ldqpos # branch to quot positive
+
+# 0x80000000 is the largest number representable as a 32-bit negative
+# number. the negative of 0x80000000 is 0x80000000.
+ cmpi.l %d6, &0x80000000 # will (-quot) fit in 32 bits?
+ bhi.b lddovf
+
+ neg.l %d6 # make (-quot) 2's comp
+
+ bra.b lddone
+
+ldqpos:
+ btst &0x1f, %d6 # will (+quot) fit in 32 bits?
+ bne.b lddovf
+
+lddone:
+# if the register numbers are the same, only the quotient gets saved.
+# so, if we always save the quotient second, we save ourselves a cmp&beq
+ andi.w &0x10,DIV64_CC(%a6)
+ mov.w DIV64_CC(%a6),%cc
+ tst.l %d6 # may set 'N' ccode bit
+
+# here, the result is in d1 and d0. the current strategy is to save
+# the values at the location pointed to by a0.
+# use movm here to not disturb the condition codes.
+ldexit:
+ movm.l &0x0060,([0x14,%a6]) # save result
+
+# EPILOGUE BEGIN ########################################################
+# fmovm.l (%sp)+,&0x0 # restore no fpregs
+ movm.l (%sp)+,&0x00fc # restore d2-d7
+ unlk %a6
+# EPILOGUE END ##########################################################
+
+ rts
+
+# the result should be the unchanged dividend
+lddovf:
+ mov.l 0xc(%a6), %d5 # get dividend hi
+ mov.l 0x10(%a6), %d6 # get dividend lo
+
+ andi.w &0x1c,DIV64_CC(%a6)
+ ori.w &0x02,DIV64_CC(%a6) # set 'V' ccode bit
+ mov.w DIV64_CC(%a6),%cc
+
+ bra.b ldexit
+
+ldiv64eq0:
+ mov.l 0xc(%a6),([0x14,%a6])
+ mov.l 0x10(%a6),([0x14,%a6],0x4)
+
+ mov.w DIV64_CC(%a6),%cc
+
+# EPILOGUE BEGIN ########################################################
+# fmovm.l (%sp)+,&0x0 # restore no fpregs
+ movm.l (%sp)+,&0x00fc # restore d2-d7
+ unlk %a6
+# EPILOGUE END ##########################################################
+
+ divu.w &0x0,%d0 # force a divbyzero exception
+ rts
+
+###########################################################################
+#########################################################################
+# This routine uses the 'classical' Algorithm D from Donald Knuth's #
+# Art of Computer Programming, vol II, Seminumerical Algorithms. #
+# For this implementation b=2**16, and the target is U1U2U3U4/V1V2, #
+# where U,V are words of the quadword dividend and longword divisor, #
+# and U1, V1 are the most significant words. #
+# #
+# The most sig. longword of the 64 bit dividend must be in %d5, least #
+# in %d6. The divisor must be in the variable ddivisor, and the #
+# signed/unsigned flag ddusign must be set (0=unsigned,1=signed). #
+# The quotient is returned in %d6, remainder in %d5, unless the #
+# v (overflow) bit is set in the saved %ccr. If overflow, the dividend #
+# is unchanged. #
+#########################################################################
+ldclassical:
+# if the divisor msw is 0, use simpler algorithm then the full blown
+# one at ddknuth:
+
+ cmpi.l %d7, &0xffff
+ bhi.b lddknuth # go use D. Knuth algorithm
+
+# Since the divisor is only a word (and larger than the mslw of the dividend),
+# a simpler algorithm may be used :
+# In the general case, four quotient words would be created by
+# dividing the divisor word into each dividend word. In this case,
+# the first two quotient words must be zero, or overflow would occur.
+# Since we already checked this case above, we can treat the most significant
+# longword of the dividend as (0) remainder (see Knuth) and merely complete
+# the last two divisions to get a quotient longword and word remainder:
+
+ clr.l %d1
+ swap %d5 # same as r*b if previous step rqd
+ swap %d6 # get u3 to lsw position
+ mov.w %d6, %d5 # rb + u3
+
+ divu.w %d7, %d5
+
+ mov.w %d5, %d1 # first quotient word
+ swap %d6 # get u4
+ mov.w %d6, %d5 # rb + u4
+
+ divu.w %d7, %d5
+
+ swap %d1
+ mov.w %d5, %d1 # 2nd quotient 'digit'
+ clr.w %d5
+ swap %d5 # now remainder
+ mov.l %d1, %d6 # and quotient
+
+ rts
+
+lddknuth:
+# In this algorithm, the divisor is treated as a 2 digit (word) number
+# which is divided into a 3 digit (word) dividend to get one quotient
+# digit (word). After subtraction, the dividend is shifted and the
+# process repeated. Before beginning, the divisor and quotient are
+# 'normalized' so that the process of estimating the quotient digit
+# will yield verifiably correct results..
+
+ clr.l DDNORMAL(%a6) # count of shifts for normalization
+ clr.b DDSECOND(%a6) # clear flag for quotient digits
+ clr.l %d1 # %d1 will hold trial quotient
+lddnchk:
+ btst &31, %d7 # must we normalize? first word of
+ bne.b lddnormalized # divisor (V1) must be >= 65536/2
+ addq.l &0x1, DDNORMAL(%a6) # count normalization shifts
+ lsl.l &0x1, %d7 # shift the divisor
+ lsl.l &0x1, %d6 # shift u4,u3 with overflow to u2
+ roxl.l &0x1, %d5 # shift u1,u2
+ bra.w lddnchk
+lddnormalized:
+
+# Now calculate an estimate of the quotient words (msw first, then lsw).
+# The comments use subscripts for the first quotient digit determination.
+ mov.l %d7, %d3 # divisor
+ mov.l %d5, %d2 # dividend mslw
+ swap %d2
+ swap %d3
+ cmp.w %d2, %d3 # V1 = U1 ?
+ bne.b lddqcalc1
+ mov.w &0xffff, %d1 # use max trial quotient word
+ bra.b lddadj0
+lddqcalc1:
+ mov.l %d5, %d1
+
+ divu.w %d3, %d1 # use quotient of mslw/msw
+
+ andi.l &0x0000ffff, %d1 # zero any remainder
+lddadj0:
+
+# now test the trial quotient and adjust. This step plus the
+# normalization assures (according to Knuth) that the trial
+# quotient will be at worst 1 too large.
+ mov.l %d6, -(%sp)
+ clr.w %d6 # word u3 left
+ swap %d6 # in lsw position
+lddadj1: mov.l %d7, %d3
+ mov.l %d1, %d2
+ mulu.w %d7, %d2 # V2q
+ swap %d3
+ mulu.w %d1, %d3 # V1q
+ mov.l %d5, %d4 # U1U2
+ sub.l %d3, %d4 # U1U2 - V1q
+
+ swap %d4
+
+ mov.w %d4,%d0
+ mov.w %d6,%d4 # insert lower word (U3)
+
+ tst.w %d0 # is upper word set?
+ bne.w lddadjd1
+
+# add.l %d6, %d4 # (U1U2 - V1q) + U3
+
+ cmp.l %d2, %d4
+ bls.b lddadjd1 # is V2q > (U1U2-V1q) + U3 ?
+ subq.l &0x1, %d1 # yes, decrement and recheck
+ bra.b lddadj1
+lddadjd1:
+# now test the word by multiplying it by the divisor (V1V2) and comparing
+# the 3 digit (word) result with the current dividend words
+ mov.l %d5, -(%sp) # save %d5 (%d6 already saved)
+ mov.l %d1, %d6
+ swap %d6 # shift answer to ms 3 words
+ mov.l %d7, %d5
+ bsr.l ldmm2
+ mov.l %d5, %d2 # now %d2,%d3 are trial*divisor
+ mov.l %d6, %d3
+ mov.l (%sp)+, %d5 # restore dividend
+ mov.l (%sp)+, %d6
+ sub.l %d3, %d6
+ subx.l %d2, %d5 # subtract double precision
+ bcc ldd2nd # no carry, do next quotient digit
+ subq.l &0x1, %d1 # q is one too large
+# need to add back divisor longword to current ms 3 digits of dividend
+# - according to Knuth, this is done only 2 out of 65536 times for random
+# divisor, dividend selection.
+ clr.l %d2
+ mov.l %d7, %d3
+ swap %d3
+ clr.w %d3 # %d3 now ls word of divisor
+ add.l %d3, %d6 # aligned with 3rd word of dividend
+ addx.l %d2, %d5
+ mov.l %d7, %d3
+ clr.w %d3 # %d3 now ms word of divisor
+ swap %d3 # aligned with 2nd word of dividend
+ add.l %d3, %d5
+ldd2nd:
+ tst.b DDSECOND(%a6) # both q words done?
+ bne.b lddremain
+# first quotient digit now correct. store digit and shift the
+# (subtracted) dividend
+ mov.w %d1, DDQUOTIENT(%a6)
+ clr.l %d1
+ swap %d5
+ swap %d6
+ mov.w %d6, %d5
+ clr.w %d6
+ st DDSECOND(%a6) # second digit
+ bra.w lddnormalized
+lddremain:
+# add 2nd word to quotient, get the remainder.
+ mov.w %d1, DDQUOTIENT+2(%a6)
+# shift down one word/digit to renormalize remainder.
+ mov.w %d5, %d6
+ swap %d6
+ swap %d5
+ mov.l DDNORMAL(%a6), %d7 # get norm shift count
+ beq.b lddrn
+ subq.l &0x1, %d7 # set for loop count
+lddnlp:
+ lsr.l &0x1, %d5 # shift into %d6
+ roxr.l &0x1, %d6
+ dbf %d7, lddnlp
+lddrn:
+ mov.l %d6, %d5 # remainder
+ mov.l DDQUOTIENT(%a6), %d6 # quotient
+
+ rts
+ldmm2:
+# factors for the 32X32->64 multiplication are in %d5 and %d6.
+# returns 64 bit result in %d5 (hi) %d6(lo).
+# destroys %d2,%d3,%d4.
+
+# multiply hi,lo words of each factor to get 4 intermediate products
+ mov.l %d6, %d2
+ mov.l %d6, %d3
+ mov.l %d5, %d4
+ swap %d3
+ swap %d4
+ mulu.w %d5, %d6 # %d6 <- lsw*lsw
+ mulu.w %d3, %d5 # %d5 <- msw-dest*lsw-source
+ mulu.w %d4, %d2 # %d2 <- msw-source*lsw-dest
+ mulu.w %d4, %d3 # %d3 <- msw*msw
+# now use swap and addx to consolidate to two longwords
+ clr.l %d4
+ swap %d6
+ add.w %d5, %d6 # add msw of l*l to lsw of m*l product
+ addx.w %d4, %d3 # add any carry to m*m product
+ add.w %d2, %d6 # add in lsw of other m*l product
+ addx.w %d4, %d3 # add any carry to m*m product
+ swap %d6 # %d6 is low 32 bits of final product
+ clr.w %d5
+ clr.w %d2 # lsw of two mixed products used,
+ swap %d5 # now use msws of longwords
+ swap %d2
+ add.l %d2, %d5
+ add.l %d3, %d5 # %d5 now ms 32 bits of final product
+ rts
+
+#########################################################################
+# XDEF **************************************************************** #
+# _060LSP__imulu64_(): Emulate 64-bit unsigned mul instruction #
+# _060LSP__imuls64_(): Emulate 64-bit signed mul instruction. #
+# #
+# This is the library version which is accessed as a subroutine #
+# and therefore does not work exactly like the 680X0 mul{s,u}.l #
+# 64-bit multiply instruction. #
+# #
+# XREF **************************************************************** #
+# None #
+# #
+# INPUT *************************************************************** #
+# 0x4(sp) = multiplier #
+# 0x8(sp) = multiplicand #
+# 0xc(sp) = pointer to location to place 64-bit result #
+# #
+# OUTPUT ************************************************************** #
+# 0xc(sp) = points to location of 64-bit result #
+# #
+# ALGORITHM *********************************************************** #
+# Perform the multiply in pieces using 16x16->32 unsigned #
+# multiplies and "add" instructions. #
+# Set the condition codes as appropriate before performing an #
+# "rts". #
+# #
+#########################################################################
+
+set MUL64_CC, -4
+
+ global _060LSP__imulu64_
+_060LSP__imulu64_:
+
+# PROLOGUE BEGIN ########################################################
+ link.w %a6,&-4
+ movm.l &0x3800,-(%sp) # save d2-d4
+# fmovm.l &0x0,-(%sp) # save no fpregs
+# PROLOGUE END ##########################################################
+
+ mov.w %cc,MUL64_CC(%a6) # save incoming ccodes
+
+ mov.l 0x8(%a6),%d0 # store multiplier in d0
+ beq.w mulu64_zero # handle zero separately
+
+ mov.l 0xc(%a6),%d1 # get multiplicand in d1
+ beq.w mulu64_zero # handle zero separately
+
+#########################################################################
+# 63 32 0 #
+# ---------------------------- #
+# | hi(mplier) * hi(mplicand)| #
+# ---------------------------- #
+# ----------------------------- #
+# | hi(mplier) * lo(mplicand) | #
+# ----------------------------- #
+# ----------------------------- #
+# | lo(mplier) * hi(mplicand) | #
+# ----------------------------- #
+# | ----------------------------- #
+# --|-- | lo(mplier) * lo(mplicand) | #
+# | ----------------------------- #
+# ======================================================== #
+# -------------------------------------------------------- #
+# | hi(result) | lo(result) | #
+# -------------------------------------------------------- #
+#########################################################################
+mulu64_alg:
+# load temp registers with operands
+ mov.l %d0,%d2 # mr in d2
+ mov.l %d0,%d3 # mr in d3
+ mov.l %d1,%d4 # md in d4
+ swap %d3 # hi(mr) in lo d3
+ swap %d4 # hi(md) in lo d4
+
+# complete necessary multiplies:
+ mulu.w %d1,%d0 # [1] lo(mr) * lo(md)
+ mulu.w %d3,%d1 # [2] hi(mr) * lo(md)
+ mulu.w %d4,%d2 # [3] lo(mr) * hi(md)
+ mulu.w %d4,%d3 # [4] hi(mr) * hi(md)
+
+# add lo portions of [2],[3] to hi portion of [1].
+# add carries produced from these adds to [4].
+# lo([1]) is the final lo 16 bits of the result.
+ clr.l %d4 # load d4 w/ zero value
+ swap %d0 # hi([1]) <==> lo([1])
+ add.w %d1,%d0 # hi([1]) + lo([2])
+ addx.l %d4,%d3 # [4] + carry
+ add.w %d2,%d0 # hi([1]) + lo([3])
+ addx.l %d4,%d3 # [4] + carry
+ swap %d0 # lo([1]) <==> hi([1])
+
+# lo portions of [2],[3] have been added in to final result.
+# now, clear lo, put hi in lo reg, and add to [4]
+ clr.w %d1 # clear lo([2])
+ clr.w %d2 # clear hi([3])
+ swap %d1 # hi([2]) in lo d1
+ swap %d2 # hi([3]) in lo d2
+ add.l %d2,%d1 # [4] + hi([2])
+ add.l %d3,%d1 # [4] + hi([3])
+
+# now, grab the condition codes. only one that can be set is 'N'.
+# 'N' CAN be set if the operation is unsigned if bit 63 is set.
+ mov.w MUL64_CC(%a6),%d4
+ andi.b &0x10,%d4 # keep old 'X' bit
+ tst.l %d1 # may set 'N' bit
+ bpl.b mulu64_ddone
+ ori.b &0x8,%d4 # set 'N' bit
+mulu64_ddone:
+ mov.w %d4,%cc
+
+# here, the result is in d1 and d0. the current strategy is to save
+# the values at the location pointed to by a0.
+# use movm here to not disturb the condition codes.
+mulu64_end:
+ exg %d1,%d0
+ movm.l &0x0003,([0x10,%a6]) # save result
+
+# EPILOGUE BEGIN ########################################################
+# fmovm.l (%sp)+,&0x0 # restore no fpregs
+ movm.l (%sp)+,&0x001c # restore d2-d4
+ unlk %a6
+# EPILOGUE END ##########################################################
+
+ rts
+
+# one or both of the operands is zero so the result is also zero.
+# save the zero result to the register file and set the 'Z' ccode bit.
+mulu64_zero:
+ clr.l %d0
+ clr.l %d1
+
+ mov.w MUL64_CC(%a6),%d4
+ andi.b &0x10,%d4
+ ori.b &0x4,%d4
+ mov.w %d4,%cc # set 'Z' ccode bit
+
+ bra.b mulu64_end
+
+##########
+# muls.l #
+##########
+ global _060LSP__imuls64_
+_060LSP__imuls64_:
+
+# PROLOGUE BEGIN ########################################################
+ link.w %a6,&-4
+ movm.l &0x3c00,-(%sp) # save d2-d5
+# fmovm.l &0x0,-(%sp) # save no fpregs
+# PROLOGUE END ##########################################################
+
+ mov.w %cc,MUL64_CC(%a6) # save incoming ccodes
+
+ mov.l 0x8(%a6),%d0 # store multiplier in d0
+ beq.b mulu64_zero # handle zero separately
+
+ mov.l 0xc(%a6),%d1 # get multiplicand in d1
+ beq.b mulu64_zero # handle zero separately
+
+ clr.b %d5 # clear sign tag
+ tst.l %d0 # is multiplier negative?
+ bge.b muls64_chk_md_sgn # no
+ neg.l %d0 # make multiplier positive
+
+ ori.b &0x1,%d5 # save multiplier sgn
+
+# the result sign is the exclusive or of the operand sign bits.
+muls64_chk_md_sgn:
+ tst.l %d1 # is multiplicand negative?
+ bge.b muls64_alg # no
+ neg.l %d1 # make multiplicand positive
+
+ eori.b &0x1,%d5 # calculate correct sign
+
+#########################################################################
+# 63 32 0 #
+# ---------------------------- #
+# | hi(mplier) * hi(mplicand)| #
+# ---------------------------- #
+# ----------------------------- #
+# | hi(mplier) * lo(mplicand) | #
+# ----------------------------- #
+# ----------------------------- #
+# | lo(mplier) * hi(mplicand) | #
+# ----------------------------- #
+# | ----------------------------- #
+# --|-- | lo(mplier) * lo(mplicand) | #
+# | ----------------------------- #
+# ======================================================== #
+# -------------------------------------------------------- #
+# | hi(result) | lo(result) | #
+# -------------------------------------------------------- #
+#########################################################################
+muls64_alg:
+# load temp registers with operands
+ mov.l %d0,%d2 # mr in d2
+ mov.l %d0,%d3 # mr in d3
+ mov.l %d1,%d4 # md in d4
+ swap %d3 # hi(mr) in lo d3
+ swap %d4 # hi(md) in lo d4
+
+# complete necessary multiplies:
+ mulu.w %d1,%d0 # [1] lo(mr) * lo(md)
+ mulu.w %d3,%d1 # [2] hi(mr) * lo(md)
+ mulu.w %d4,%d2 # [3] lo(mr) * hi(md)
+ mulu.w %d4,%d3 # [4] hi(mr) * hi(md)
+
+# add lo portions of [2],[3] to hi portion of [1].
+# add carries produced from these adds to [4].
+# lo([1]) is the final lo 16 bits of the result.
+ clr.l %d4 # load d4 w/ zero value
+ swap %d0 # hi([1]) <==> lo([1])
+ add.w %d1,%d0 # hi([1]) + lo([2])
+ addx.l %d4,%d3 # [4] + carry
+ add.w %d2,%d0 # hi([1]) + lo([3])
+ addx.l %d4,%d3 # [4] + carry
+ swap %d0 # lo([1]) <==> hi([1])
+
+# lo portions of [2],[3] have been added in to final result.
+# now, clear lo, put hi in lo reg, and add to [4]
+ clr.w %d1 # clear lo([2])
+ clr.w %d2 # clear hi([3])
+ swap %d1 # hi([2]) in lo d1
+ swap %d2 # hi([3]) in lo d2
+ add.l %d2,%d1 # [4] + hi([2])
+ add.l %d3,%d1 # [4] + hi([3])
+
+ tst.b %d5 # should result be signed?
+ beq.b muls64_done # no
+
+# result should be a signed negative number.
+# compute 2's complement of the unsigned number:
+# -negate all bits and add 1
+muls64_neg:
+ not.l %d0 # negate lo(result) bits
+ not.l %d1 # negate hi(result) bits
+ addq.l &1,%d0 # add 1 to lo(result)
+ addx.l %d4,%d1 # add carry to hi(result)
+
+muls64_done:
+ mov.w MUL64_CC(%a6),%d4
+ andi.b &0x10,%d4 # keep old 'X' bit
+ tst.l %d1 # may set 'N' bit
+ bpl.b muls64_ddone
+ ori.b &0x8,%d4 # set 'N' bit
+muls64_ddone:
+ mov.w %d4,%cc
+
+# here, the result is in d1 and d0. the current strategy is to save
+# the values at the location pointed to by a0.
+# use movm here to not disturb the condition codes.
+muls64_end:
+ exg %d1,%d0
+ movm.l &0x0003,([0x10,%a6]) # save result at (a0)
+
+# EPILOGUE BEGIN ########################################################
+# fmovm.l (%sp)+,&0x0 # restore no fpregs
+ movm.l (%sp)+,&0x003c # restore d2-d5
+ unlk %a6
+# EPILOGUE END ##########################################################
+
+ rts
+
+# one or both of the operands is zero so the result is also zero.
+# save the zero result to the register file and set the 'Z' ccode bit.
+muls64_zero:
+ clr.l %d0
+ clr.l %d1
+
+ mov.w MUL64_CC(%a6),%d4
+ andi.b &0x10,%d4
+ ori.b &0x4,%d4
+ mov.w %d4,%cc # set 'Z' ccode bit
+
+ bra.b muls64_end
+
+#########################################################################
+# XDEF **************************************************************** #
+# _060LSP__cmp2_Ab_(): Emulate "cmp2.b An,<ea>". #
+# _060LSP__cmp2_Aw_(): Emulate "cmp2.w An,<ea>". #
+# _060LSP__cmp2_Al_(): Emulate "cmp2.l An,<ea>". #
+# _060LSP__cmp2_Db_(): Emulate "cmp2.b Dn,<ea>". #
+# _060LSP__cmp2_Dw_(): Emulate "cmp2.w Dn,<ea>". #
+# _060LSP__cmp2_Dl_(): Emulate "cmp2.l Dn,<ea>". #
+# #
+# This is the library version which is accessed as a subroutine #
+# and therefore does not work exactly like the 680X0 "cmp2" #
+# instruction. #
+# #
+# XREF **************************************************************** #
+# None #
+# #
+# INPUT *************************************************************** #
+# 0x4(sp) = Rn #
+# 0x8(sp) = pointer to boundary pair #
+# #
+# OUTPUT ************************************************************** #
+# cc = condition codes are set correctly #
+# #
+# ALGORITHM *********************************************************** #
+# In the interest of simplicity, all operands are converted to #
+# longword size whether the operation is byte, word, or long. The #
+# bounds are sign extended accordingly. If Rn is a data regsiter, Rn is #
+# also sign extended. If Rn is an address register, it need not be sign #
+# extended since the full register is always used. #
+# The condition codes are set correctly before the final "rts". #
+# #
+#########################################################################
+
+set CMP2_CC, -4
+
+ global _060LSP__cmp2_Ab_
+_060LSP__cmp2_Ab_:
+
+# PROLOGUE BEGIN ########################################################
+ link.w %a6,&-4
+ movm.l &0x3800,-(%sp) # save d2-d4
+# fmovm.l &0x0,-(%sp) # save no fpregs
+# PROLOGUE END ##########################################################
+
+ mov.w %cc,CMP2_CC(%a6)
+ mov.l 0x8(%a6), %d2 # get regval
+
+ mov.b ([0xc,%a6],0x0),%d0
+ mov.b ([0xc,%a6],0x1),%d1
+
+ extb.l %d0 # sign extend lo bnd
+ extb.l %d1 # sign extend hi bnd
+ bra.w l_cmp2_cmp # go do the compare emulation
+
+ global _060LSP__cmp2_Aw_
+_060LSP__cmp2_Aw_:
+
+# PROLOGUE BEGIN ########################################################
+ link.w %a6,&-4
+ movm.l &0x3800,-(%sp) # save d2-d4
+# fmovm.l &0x0,-(%sp) # save no fpregs
+# PROLOGUE END ##########################################################
+
+ mov.w %cc,CMP2_CC(%a6)
+ mov.l 0x8(%a6), %d2 # get regval
+
+ mov.w ([0xc,%a6],0x0),%d0
+ mov.w ([0xc,%a6],0x2),%d1
+
+ ext.l %d0 # sign extend lo bnd
+ ext.l %d1 # sign extend hi bnd
+ bra.w l_cmp2_cmp # go do the compare emulation
+
+ global _060LSP__cmp2_Al_
+_060LSP__cmp2_Al_:
+
+# PROLOGUE BEGIN ########################################################
+ link.w %a6,&-4
+ movm.l &0x3800,-(%sp) # save d2-d4
+# fmovm.l &0x0,-(%sp) # save no fpregs
+# PROLOGUE END ##########################################################
+
+ mov.w %cc,CMP2_CC(%a6)
+ mov.l 0x8(%a6), %d2 # get regval
+
+ mov.l ([0xc,%a6],0x0),%d0
+ mov.l ([0xc,%a6],0x4),%d1
+ bra.w l_cmp2_cmp # go do the compare emulation
+
+ global _060LSP__cmp2_Db_
+_060LSP__cmp2_Db_:
+
+# PROLOGUE BEGIN ########################################################
+ link.w %a6,&-4
+ movm.l &0x3800,-(%sp) # save d2-d4
+# fmovm.l &0x0,-(%sp) # save no fpregs
+# PROLOGUE END ##########################################################
+
+ mov.w %cc,CMP2_CC(%a6)
+ mov.l 0x8(%a6), %d2 # get regval
+
+ mov.b ([0xc,%a6],0x0),%d0
+ mov.b ([0xc,%a6],0x1),%d1
+
+ extb.l %d0 # sign extend lo bnd
+ extb.l %d1 # sign extend hi bnd
+
+# operation is a data register compare.
+# sign extend byte to long so we can do simple longword compares.
+ extb.l %d2 # sign extend data byte
+ bra.w l_cmp2_cmp # go do the compare emulation
+
+ global _060LSP__cmp2_Dw_
+_060LSP__cmp2_Dw_:
+
+# PROLOGUE BEGIN ########################################################
+ link.w %a6,&-4
+ movm.l &0x3800,-(%sp) # save d2-d4
+# fmovm.l &0x0,-(%sp) # save no fpregs
+# PROLOGUE END ##########################################################
+
+ mov.w %cc,CMP2_CC(%a6)
+ mov.l 0x8(%a6), %d2 # get regval
+
+ mov.w ([0xc,%a6],0x0),%d0
+ mov.w ([0xc,%a6],0x2),%d1
+
+ ext.l %d0 # sign extend lo bnd
+ ext.l %d1 # sign extend hi bnd
+
+# operation is a data register compare.
+# sign extend word to long so we can do simple longword compares.
+ ext.l %d2 # sign extend data word
+ bra.w l_cmp2_cmp # go emulate compare
+
+ global _060LSP__cmp2_Dl_
+_060LSP__cmp2_Dl_:
+
+# PROLOGUE BEGIN ########################################################
+ link.w %a6,&-4
+ movm.l &0x3800,-(%sp) # save d2-d4
+# fmovm.l &0x0,-(%sp) # save no fpregs
+# PROLOGUE END ##########################################################
+
+ mov.w %cc,CMP2_CC(%a6)
+ mov.l 0x8(%a6), %d2 # get regval
+
+ mov.l ([0xc,%a6],0x0),%d0
+ mov.l ([0xc,%a6],0x4),%d1
+
+#
+# To set the ccodes correctly:
+# (1) save 'Z' bit from (Rn - lo)
+# (2) save 'Z' and 'N' bits from ((hi - lo) - (Rn - hi))
+# (3) keep 'X', 'N', and 'V' from before instruction
+# (4) combine ccodes
+#
+l_cmp2_cmp:
+ sub.l %d0, %d2 # (Rn - lo)
+ mov.w %cc, %d3 # fetch resulting ccodes
+ andi.b &0x4, %d3 # keep 'Z' bit
+ sub.l %d0, %d1 # (hi - lo)
+ cmp.l %d1,%d2 # ((hi - lo) - (Rn - hi))
+
+ mov.w %cc, %d4 # fetch resulting ccodes
+ or.b %d4, %d3 # combine w/ earlier ccodes
+ andi.b &0x5, %d3 # keep 'Z' and 'N'
+
+ mov.w CMP2_CC(%a6), %d4 # fetch old ccodes
+ andi.b &0x1a, %d4 # keep 'X','N','V' bits
+ or.b %d3, %d4 # insert new ccodes
+ mov.w %d4,%cc # save new ccodes
+
+# EPILOGUE BEGIN ########################################################
+# fmovm.l (%sp)+,&0x0 # restore no fpregs
+ movm.l (%sp)+,&0x001c # restore d2-d4
+ unlk %a6
+# EPILOGUE END ##########################################################
+
+ rts

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