474 lines
6.7 KiB
ArmAsm
474 lines
6.7 KiB
ArmAsm
! floating point pakket voor Z80
|
|
! geimplementeerd zoals beschreven in
|
|
! Electronica top internationaal.
|
|
! September 1979
|
|
! Auteur: Hr. R. Beverdam, Zuidbroekweg 9,7642 NW Wierden
|
|
|
|
xa: .space 1
|
|
fpac:
|
|
fal: .space 1
|
|
fan: .space 1
|
|
fam: .space 1
|
|
fax: .space 1
|
|
xo: .space 1
|
|
fpop:
|
|
fol: .space 1
|
|
fon: .space 1
|
|
fom: .space 1
|
|
fox: .space 1
|
|
.errnz xa/256-fox/256
|
|
|
|
fpsub:
|
|
call fpcomp ! inverteer fpacc
|
|
fpadd:
|
|
ld de,(fam) ! d fax,e fam
|
|
ld bc,(fom) ! b fox,c fom
|
|
ld a,e ! test fpacc
|
|
or a ! 0?
|
|
jr z,movop ! ja: som=fpop dus verplaats
|
|
xor a
|
|
add a,c
|
|
ret z ! som is dus fpacc, klaar
|
|
ld a,b
|
|
sub d ! a:=fox-fax
|
|
ld l,a ! bewaar verschil exponenten
|
|
jp p,skpneg ! maak positief
|
|
neg
|
|
skpneg:
|
|
cp 0x18 ! verschil meer dan 23?
|
|
ld a,l
|
|
jp m,lineup ! spring indien binnen bereik
|
|
and a ! getallen te groot tov elkaar
|
|
ret m ! klaar als fpacc het grootst
|
|
movop:
|
|
ld hl,fol ! verplaats fpop naar fpacc
|
|
ld de,fal ! want fpop is het antwoord
|
|
ld bc,4
|
|
ldir
|
|
ret
|
|
lineup:
|
|
and a ! kijk welke groter is
|
|
jp m,shifto ! spring als fpop>fpac
|
|
inc a ! bereken sa
|
|
ld b,a ! save sa in b register
|
|
ld a,1 ! so 1
|
|
push af ! bewaar so op stapel
|
|
jr shacop ! gr schuiven
|
|
shifto:
|
|
neg ! bereken fox-fax
|
|
eqexp:
|
|
inc a ! so 1+(fox-fax)
|
|
push af ! bewaar so op stapel
|
|
ld b,1 ! sa 1
|
|
shacop:
|
|
ld hl,(fal) ! l fal,h fan
|
|
xor a ! xa 0
|
|
moracc:
|
|
sra e ! schuif fam
|
|
rr h ! fan
|
|
rr l ! fal
|
|
rra ! xa
|
|
inc d ! update voor fax
|
|
djnz moracc ! herhaal sa keer
|
|
ld (xa),a ! berg alles
|
|
ld (fal),hl ! weg in
|
|
ld (fam),de ! fpacc en xa
|
|
pop af ! haal so terug van stapel
|
|
ld b,a ! en zet in b register
|
|
xor a ! xo 0
|
|
ld hl,(fol) ! l fol,h fon
|
|
morop:
|
|
sra c ! schuif: fom
|
|
rr h ! fon
|
|
rr l !
|
|
rra ! xo
|
|
djnz morop ! herhaal so keer
|
|
ld (xo),a
|
|
ld (fol),hl
|
|
ld (fom),bc ! berg alles weg in fpop en xo
|
|
ld de,xa
|
|
ld hl,xo
|
|
ld b,4
|
|
or a ! reset carry
|
|
addmor:
|
|
ld a,(de) ! haal een byte
|
|
adc a,(hl) ! tel er een bij op
|
|
ld (de),a ! en berg de som weer op
|
|
inc e
|
|
inc l
|
|
djnz addmor ! herhaal dit 4 keer
|
|
jr fpnorm
|
|
|
|
fpmult:
|
|
call setsgn
|
|
add a,(hl) ! bereken exponent produkt
|
|
ld (hl),a ! fax exponent produkt
|
|
ld l,fom%256
|
|
ex de,hl ! gebruik de als wijzer
|
|
xor a
|
|
ld h,a
|
|
ld l,a ! hoogste 16 bits van pp worden nul
|
|
exx
|
|
ld bc,(fal)
|
|
ld de,(fam) ! haal mc in registers
|
|
ld d,a ! d:=0 tbv 16-bit add
|
|
ld h,a
|
|
ld l,a ! middelste 16 bits van pp worden nul
|
|
ld ix,0 ! laagste 16 bits ook
|
|
exx
|
|
ld c,3
|
|
mult:
|
|
ld a,(de) ! haal een byte van mr
|
|
dec e
|
|
ld b,8 ! bits in a byte
|
|
shift:
|
|
rla ! schuif vooste bit in carry
|
|
exx
|
|
jr nc,noadd ! vooste bit is 0, dan niet optellen
|
|
add ix,bc ! pp:=pp+mc
|
|
adc hl,de ! continued
|
|
noadd:
|
|
add ix,ix
|
|
adc hl,hl
|
|
exx
|
|
adc hl,hl ! dit schoof het hele partiele produkt <
|
|
djnz shift ! herhaal voor alle 8 bits
|
|
dec c
|
|
jr nz,mult ! herhaal voor 3 bytes
|
|
exx
|
|
rl l
|
|
rla
|
|
add a,h
|
|
ld (fal),a
|
|
ld a,d
|
|
exx
|
|
adc a,l
|
|
ld (fan),a ! rond getal in pp af en berg resultaat op
|
|
ld a,c
|
|
adc a,h
|
|
ld (fam),a
|
|
call fpnorm
|
|
exmldv:
|
|
ld hl,xa
|
|
ld c,(hl)
|
|
jp resign ! fix sign
|
|
|
|
fpdiv:
|
|
call setsgn
|
|
sub (hl)
|
|
ld (hl),a ! berg exponent quotient op
|
|
ld hl,(fol)
|
|
push hl
|
|
pop ix
|
|
ld de,(fal)
|
|
ld a,(fam)
|
|
or a ! fpacc = 0 ?
|
|
jr z,fperr ! fout, deling door nul
|
|
ld b,a ! b:=fam
|
|
ld a,(fom)
|
|
ld c,a
|
|
exx
|
|
ld hl,fam
|
|
ld e,3
|
|
divide:
|
|
ld b,8
|
|
mordiv:
|
|
exx
|
|
and a
|
|
sbc hl,de
|
|
sbc a,b ! probeer de aftrekking
|
|
jp m,nogo ! gaat niet
|
|
push hl
|
|
pop ix
|
|
ld c,a
|
|
ex af,af2 ! quotient in tweede accumulator
|
|
scf
|
|
jr quorot
|
|
nogo:
|
|
ex af,af2
|
|
or a
|
|
quorot:
|
|
rla ! volgende bit in quotient
|
|
ex af,af2
|
|
add ix,ix ! schuif eventueel vernieuwde
|
|
rl c ! dd naar links
|
|
push ix
|
|
pop hl
|
|
ld a,c ! zet nieuwe dd in rekenregisters
|
|
exx
|
|
djnz mordiv ! herhaal 8 keer
|
|
ex af,af2
|
|
ld (hl),a ! zet een byte van het quotient in het geheugen
|
|
dec l
|
|
ex af,af2
|
|
dec e
|
|
jr nz,divide ! herhaal 3 keer
|
|
ld bc,(fal)
|
|
ld hl,(fam) ! haal quotient terug in cpu
|
|
bit 7,l
|
|
jp z,exmldv ! als niet te groot tekenherstellen
|
|
ld a,1 ! wel te groot
|
|
add a,c ! eerst getal afronden
|
|
ld c,a
|
|
ld a,e
|
|
adc a,b
|
|
ld b,a
|
|
ld a,e
|
|
adc a,l
|
|
ld l,a
|
|
shft:
|
|
inc h ! nu getal naar rechts schuiven
|
|
rr l
|
|
rr b
|
|
rr c
|
|
or a
|
|
bit 7,l
|
|
jr nz,shft ! door afronding weer te groot
|
|
ld (fal),bc
|
|
ld (fam),hl
|
|
jr exmldv ! inspecteer teken
|
|
setsgn:
|
|
ld a,(fom) ! ******** setsgn ************
|
|
ld c,1 ! teken -1
|
|
rlca ! fpop 0 ?
|
|
jr nc,tstacc ! nee
|
|
rrc c ! ja, dus teken:=teken*(-1)
|
|
ld hl,fol ! en inverteer fpop
|
|
call complm
|
|
tstacc:
|
|
ld a,(fam)
|
|
rlca ! fpacc 0?
|
|
jr nc,init ! nee
|
|
rrc c ! ja dus teken:=teken*(-1)
|
|
call fpcomp
|
|
init:
|
|
ld hl,xa ! initialiseer nog een paar registers
|
|
ld (hl),c
|
|
ld a,(fox)
|
|
ld l,fax%256
|
|
ret
|
|
|
|
fpcif:
|
|
ld de,(fpac) ! integer to convert
|
|
xor a
|
|
sra d
|
|
rr e
|
|
rr a
|
|
ld (fan),de
|
|
ld (fal),a
|
|
ld a,16
|
|
ld (fax),a
|
|
jr fpnorm
|
|
|
|
fpcfi:
|
|
ld a,(fax)
|
|
dec a
|
|
jp m,fpzero ! really integer zero here
|
|
sub 15
|
|
jp p,fperr ! overflow
|
|
ld de,(fan)
|
|
inc a
|
|
neg
|
|
jr z,2f
|
|
ld b,a
|
|
ld a,(fal)
|
|
1:
|
|
sra d
|
|
rr e
|
|
rr a
|
|
djnz 1b
|
|
2:
|
|
bit 7,d
|
|
jr z,0f
|
|
inc de
|
|
0:
|
|
ld (fpac),de
|
|
ret
|
|
|
|
fpcdf:
|
|
ld de,(fpac)
|
|
ld bc,(fpac+2)
|
|
ld h,31
|
|
3:
|
|
ld a,b
|
|
and 0300
|
|
jr z,1f
|
|
cp 0300
|
|
jr z,1f
|
|
or a
|
|
jp p,2f
|
|
sra b
|
|
rr c
|
|
rr d
|
|
inc h
|
|
2:
|
|
ld a,h
|
|
ld (fax),a
|
|
ld (fan),bc
|
|
ld a,d
|
|
ld (fal),a
|
|
ret
|
|
1:
|
|
sla e
|
|
rl d
|
|
rl c
|
|
rl b
|
|
dec h
|
|
jr 3b
|
|
|
|
fpcfd:
|
|
ld a,(fax)
|
|
dec a
|
|
jp m,fpzero
|
|
cp 32
|
|
jp p,fperr
|
|
sub 31
|
|
cpl
|
|
ld bc,(fan)
|
|
ld de,(fal)
|
|
ld d,e
|
|
ld e,0
|
|
1:
|
|
dec a
|
|
jp m,2f
|
|
sra b
|
|
rr c
|
|
rr d
|
|
rr e
|
|
jr 1b
|
|
2:
|
|
bit 7,b
|
|
jr z,3f
|
|
sla e
|
|
rl d
|
|
rl c
|
|
rl b
|
|
3:
|
|
ld (fpac+2),bc
|
|
ld (fpac),de
|
|
ret
|
|
fpfef:
|
|
ld a,(fox)
|
|
ld (fpac),a
|
|
9:
|
|
bit 7,a
|
|
jr z,1f
|
|
ld a,0xFF
|
|
jr 2f
|
|
1:
|
|
xor a
|
|
2:
|
|
ld (fpac+1),a
|
|
xor a
|
|
ld (fox),a
|
|
ret
|
|
fpcmf:
|
|
call fpsub
|
|
ld a,(fam)
|
|
ld (fpac),a
|
|
jr 9b
|
|
fpfif:
|
|
call fpmult
|
|
ld a,(fax)
|
|
dec a
|
|
jp m,intzero
|
|
inc a
|
|
ld b,a
|
|
xor a
|
|
ld c,0200
|
|
ld d,a
|
|
ld e,a
|
|
1:
|
|
sra c
|
|
rr d
|
|
rr e
|
|
djnz 1b
|
|
ld hl,fam
|
|
ld b,(hl)
|
|
ld a,c
|
|
and b
|
|
ld (fom),a
|
|
ld a,c
|
|
xor 0177
|
|
and b
|
|
ld (hl),a
|
|
dec l
|
|
ld b,(hl)
|
|
ld a,d
|
|
and b
|
|
ld (fon),a
|
|
ld a,d
|
|
cpl
|
|
and b
|
|
ld (hl),a
|
|
dec l
|
|
ld b,(hl)
|
|
ld a,e
|
|
and b
|
|
ld (fol),a
|
|
ld a,e
|
|
cpl
|
|
and b
|
|
ld (hl),a
|
|
ld a,(fax)
|
|
ld (fox),a
|
|
jr fpnorm
|
|
intzero:
|
|
xor a
|
|
ld hl,fol
|
|
ld b,4
|
|
1: ld (hl),a
|
|
inc hl
|
|
djnz 1b
|
|
ret
|
|
|
|
fpzero:
|
|
xor a
|
|
ld h,a
|
|
ld l,a
|
|
ld (fal),hl
|
|
ld (fam),hl
|
|
ret
|
|
|
|
fpnorm:
|
|
ld a,(fam)
|
|
ld c,a
|
|
or a ! fpacc < 0 ?
|
|
call m,fpcomp ! ja -- inverteer
|
|
ld hl,(fal)
|
|
ld de,(fam)
|
|
ld a,l
|
|
or h
|
|
or e
|
|
jr z,fpzero ! als hele facc 0 is
|
|
ld a,e
|
|
mortst:
|
|
bit 6,a ! test meest significante bit
|
|
jr nz,catch ! stop als bit is 1
|
|
add hl,hl ! schuif links zolang bit = 0
|
|
adc a,a
|
|
dec d ! pas fax ook aan
|
|
jr mortst
|
|
catch:
|
|
ld e,a ! herstel nu fpacc in geheugen
|
|
ld (fal),hl
|
|
ld (fam),de
|
|
resign:
|
|
bit 7,c ! test op teken
|
|
ret z ! positief, geen actie
|
|
fpcomp:
|
|
ld hl,fal
|
|
complm:
|
|
ld b,3 ! inverteer alleen mantisse
|
|
xor a
|
|
morcom:
|
|
sbc a,(hl)
|
|
ld (hl),a
|
|
inc hl
|
|
ld a,0
|
|
djnz morcom
|
|
or a
|
|
ret
|
|
fperr:
|
|
scf
|
|
ret
|