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fp3.s
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1980-02-17
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4KB
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420 lines
/ fp3 -- floating simulation
i.addx:
jsr pc,setab
br 1f
i.subx:
jsr pc,setab
neg bsign
1:
tst bsign
beq reta
tst asign
beq retb
mov areg+8,r1
sub breg+8,r1
blt 1f
beq 2f
cmp r1,$56.
bge reta
mov $breg,r0
br 4f
1:
neg r1
cmp r1,$56.
bge retb
mov $areg,r0
4:
mov r1,-(sp)
mov (r0)+,r1
mov (r0)+,r2
mov (r0)+,r3
mov (r0)+,r4
add (sp),(r0)
1:
clc
ror r1
ror r2
ror r3
ror r4
dec (sp)
bgt 1b
mov r4,-(r0)
mov r3,-(r0)
mov r2,-(r0)
mov r1,-(r0)
tst (sp)+
2:
mov $areg+8,r1
mov $breg+8,r2
mov $4,r0
cmp asign,bsign
bne 4f
clc
1:
adc -(r1)
bcs 3f
add -(r2),(r1)
2:
dec r0
bne 1b
br 5f
3:
add -(r2),(r1)
sec
br 2b
br 5f
4:
clc
1:
sbc -(r1)
bcs 3f
sub -(r2),(r1)
2:
dec r0
bne 1b
br 5f
3:
sub -(r2),(r1)
sec
br 2b
saret:
mov $areg,r1
5:
tst (r1)
bge 3f
mov $areg+8,r1
mov $4,r0
clc
1:
adc -(r1)
bcs 2f
neg (r1)
2:
dec r0
bne 1b
neg -(r1)
3:
jsr pc,norm
br reta
retb:
mov $bsign,r1
mov $asign,r2
mov $6,r0
1:
mov (r1)+,(r2)+
dec r0
bne 1b
reta:
mov r5,r2
mov $asign,r0
tst (r0)
beq unflo
mov aexp,r1
cmp r1,$177
bgt ovflo
cmp r1,$-177
blt unflo
add $200,r1
swab r1
clc
ror r1
tst (r0)+
bge 1f
bis $100000,r1
1:
bic $!177,(r0)
bis (r0)+,r1
mov r1,(r2)+
mov (r0)+,(r2)+
bit $m.ext,fpsr
beq 1f
mov (r0)+,(r2)+
mov (r0)+,(r2)+
1:
rts pc
unflo:
clr (r2)+
clr (r2)+
bit $m.ext,fpsr
beq 1f
clr (r2)+
clr (r2)+
1:
rts pc
ovflo:
bis $2,fpsr / set v-bit (overflow)
jmp ret
i.mulx:
jsr pc,i.mul
br saret
i.modx:
jsr pc,i.mul
jsr pc,norm
mov $asign,r0
mov $bsign,r1
mov $6,r2
1:
mov (r0)+,(r1)+
dec r2
bne 1b
clr r0 / count
mov $200,r1 / bit
clr r2 / reg offset
1:
cmp r0,aexp
bge 2f / in fraction
bic r1,areg(r2)
br 3f
2:
bic r1,breg(r2)
3:
inc r0
clc
ror r1
bne 1b
mov $100000,r1
add $2,r2
cmp r2,$8
blt 1b
jsr pc,norm
jsr pc,reta
cmp r5,$ac1
beq 1f
cmp r5,$ac3
beq 1f
bit $200,breg
bne 2f
clr bsign
2:
add $8,r5
jsr pc,retb
sub $8,r5
1:
rts pc
i.divx:
jsr pc,setab
tst bsign
beq ovflo
sub bexp,aexp
jsr pc,xorsign
mov r5,-(sp)
mov $areg,r0
mov (r0),r1
clr (r0)+
mov (r0),r2
clr (r0)+
mov (r0),r3
clr (r0)+
mov (r0),r4
clr (r0)+
mov $areg,r5
mov $400,-(sp)
1:
mov $breg,r0
cmp (r0)+,r1
blt 2f
bgt 3f
cmp (r0)+,r2
blo 2f
bhi 3f
cmp (r0)+,r3
blo 2f
bhi 3f
cmp (r0)+,r4
bhi 3f
2:
mov $breg+10,r0
sub -(r0),r4
sbc r3
sbc r2
sbc r1
sub -(r0),r3
sbc r2
sbc r1
sub -(r0),r2
sbc r1
sub -(r0),r1
bis (sp),(r5)
3:
asl r4
rol r3
rol r2
rol r1
clc
ror (sp)
bne 1b
mov $100000,(sp)
add $2,r5
cmp r5,$areg+8
blo 1b
tst (sp)+
mov (sp)+,r5
jmp saret
i.mul:
jsr pc,setab
add bexp,aexp
dec aexp
jsr pc,xorsign
mov r5,-(sp)
mov $breg+4,r5
bit $m.ext,fpsr
bne 3f
1:
clr r0
clr r1
clr r2
clr r3
clr r4
1:
asl r0
bne 2f
inc r0
tst -(r5)
2:
cmp r0,$400
bne 2f
cmp r5,$breg
bhi 2f
mov $areg,r0
mov r1,(r0)+
mov r2,(r0)+
mov r3,(r0)+
mov r4,(r0)+
mov (sp)+,r5
rts pc
2:
clc
ror r1
ror r2
ror r3
ror r4
bit r0,(r5)
beq 1b
mov r0,-(sp)
mov $areg,r0
add (r0)+,r1
clr -(sp)
add (r0)+,r2
adc (sp)
clr -(sp)
add (r0)+,r3
adc (sp)
add (r0)+,r4
adc r3
adc (sp)
add (sp)+,r2
adc (sp)
add (sp)+,r1
mov (sp)+,r0
br 1b
3:
mov $bins,r5
mov areg,r1
mov areg+2,r2
mov areg+4,r3
mov areg+6,r4
mov r1,(r5)+
mov r2,(r5)+
mov r3,(r5)+
mov r4,(r5)+
clc
asl r4
rol r3
rol r2
rol r1
mov r1,(r5)+
mov r2,(r5)+
mov r3,(r5)+
mov r4,(r5)+
mov $areg+10,r0
jsr pc,addr
mov r1,(r5)+
mov r2,(r5)+
mov r3,(r5)+
mov r4,(r5)+
clr r1
clr r2
clr r3
clr r4
mov $breg+6,r5
mov $10,-(sp)
4:
mov (r5),r0
ror (r5)
ror (r5)
clc
ror r1
ror r2
ror r3
ror r4
clc
ror r1
ror r2
ror r3
ror r4
bic $177774,r0
beq 1f
ash $3,r0
add $bins,r0
jsr pc,addr
1:
dec (sp)
bne 4b
cmp r5,$breg+2
beq 1f
mov $10,(sp)
br 2f
1:
mov $4,(sp)
2:
tst -(r5)
cmp r5,$breg
bhis 4b
tst (sp)+
clc
ror r1
ror r2
ror r3
ror r4
mov $areg,r0
mov r1,(r0)+
mov r2,(r0)+
mov r3,(r0)+
mov r4,(r0)+
mov (sp)+,r5
rts pc
addr:
add -(r0),r4
adc r3
adc r2
adc r1
add -(r0),r3
adc r2
adc r1
add -(r0),r2
adc r1
add -(r0),r1
rts pc
xorsign:
cmp asign,bsign
beq 1f
mov $-1,asign
rts pc
1:
mov $1,asign
rts pc