minnie.tuhs.org/unixen.tar/unixen/PDP-11/Trees/V6/usr/source/as/as16.s

Text File | 1975-07-17 | 2.8 KB | 292 lines

/
/

/ a6 -- pdp-11 assembler pass 1

opline:
    mov    r4,r0
    jsr    r5,betwen; 0; 200
        br    1f
    cmp    r0,$'<
    bne    xpr
    jmp    opl17
xpr:
    jsr    pc,expres
    add    $2,dot
    rts    pc
1:
    movb    (r4),r0
    cmp    r0,$24
    beq    xpr
    jsr    r5,betwen; 5; 36
        br xpr
    mov    r0,-(sp)
    jsr    pc,readop
    mov    (sp)+,r0
    asl    r0
    jmp    *1f-12(r0)

1:
    opl13    / map fop freg,fdst to double
    opl6
    opl7
    opl10
    opl11
    opl13    / map fld/fst to double
    opl13
    opl13    / map fop fsrc,freg to double
    opl15
    opl16
    opl17
    opl20
    opl21
    opl22
    opl23
    xpr
    opl25
    opl26
    opl27
    opl13  / map mul s,r to double
    opl31
    opl32
    xpr
    xpr
    opl35
    opl36

/ jbr
opl35:
    mov    $4,-(sp)
    br    1f

/ jeq, etc
opl36:
    mov    $6,-(sp)
1:
    jsr    pc,expres
    cmp    r3,dotrel
    bne    1f
    sub    dot,r2
    bge    1f
    cmp    r2,$-376
    blt    1f
    mov    $2,(sp)
1:
    add    (sp)+,dot
    rts    pc

/double
opl13:
opl7:
    jsr    pc,addres
op2:
    cmp    r4,$',
    beq    1f
    jsr    pc,errora
    rts    pc
1:
    jsr    pc,readop
opl15:   / single operand
    jsr    pc,addres
    add    $2,dot
    rts    pc

opl31:    / sob
    jsr    pc,expres
    cmp    r4,$',
    beq    1f
    jsr    pc,errora
1:
    jsr    pc,readop

/branch
opl6:
opl10:
opl11:
    jsr    pc,expres
    add    $2,dot
    rts    pc

/ .byte
opl16:
    jsr    pc,expres
    inc    dot
    cmp    r4,$',
    bne    1f
    jsr    pc,readop
    br    opl16
1:
    rts    pc

/ < (.ascii)
opl17:
    add    numval,dot
    jsr    pc,readop
    rts    pc

/.even
opl20:
    inc    dot
    bic    $1,dot
    rts    pc

/.if
opl21:
    jsr    pc,expres
    tst    r3
    bne    1f
    jsr    r5,error; 'U
1:
    tst    r2
    bne    opl22
    inc    ifflg
opl22:    /endif
    rts    pc

/.globl
opl23:
    cmp    r4,$200
    blo    1f
    bisb    $40,(r4)
    jsr    pc,readop
    cmp    r4,$',
    bne    1f
    jsr    pc,readop
    br    opl23
1:
    rts    pc

opl25:
opl26:
opl27:
    mov    dotrel,r1
    asl    r1
    mov    dot,savdot-4(r1)
    mov    savdot-[2*25](r0),dot
    asr    r0
    sub    $25-2,r0
    mov    r0,dotrel
    rts    pc

/ .common
opl32:
    cmp    r4,$200
    blo    1f
    bis    $40,(r4)
    jsr    pc,readop
    cmp    r4,$',
    bne    1f
    jsr    pc,readop
    jsr    pc,expres
    rts    pc
1:
    jsr    r5,error; 'x
    rts    pc

addres:
    cmp    r4,$'(
    beq    alp
    cmp    r4,$'-
    beq    amin
    cmp    r4,$'$
    beq    adoll
    cmp    r4,$'*
    beq    astar
getx:
    jsr    pc,expres
    cmp    r4,$'(
    bne    2f
    jsr    pc,readop
    jsr    pc,expres
    jsr    pc,checkreg
    jsr    pc,checkrp
    add    $2,dot
    clr    r0
    rts    pc
2:
    cmp    r3,$24        / register type
    bne    1f
    jsr    pc,checkreg
    clr    r0
    rts    pc
1:
    add    $2,dot
    clr    r0
    rts    pc

alp:
    jsr    pc,readop
    jsr    pc,expres
    jsr    pc,checkrp
    jsr    pc,checkreg
    cmp    r4,$'+
    bne    1f
    jsr    pc,readop
    clr    r0
    rts    pc
1:
    mov    $2,r0
    rts    pc

amin:
    jsr    pc,readop
    cmp    r4,$'(
    beq    1f
    mov    r4,savop
    mov    $'-,r4
    br    getx
1:
    jsr    pc,readop
    jsr    pc,expres
    jsr    pc,checkrp
    jsr    pc,checkreg
    clr    r0
    rts    pc

adoll:
    jsr    pc,readop
    jsr    pc,expres
    add    $2,dot
    clr    r0
    rts    pc

astar:
    jsr    pc,readop
    cmp    r4,$'*
    bne    1f
    jsr    r5,error; '*
1:
    jsr    pc,addres
    add    r0,dot
    rts    pc

errora:
    jsr    r5,error; 'a
    rts    pc

checkreg:
    cmp    r2,$7
    bhi    1f
    cmp    r3,$1
    beq    2f
    cmp    r3,$4
    bhi    2f
1:
    jsr    pc,errora
2:
    rts    pc

errore:
    jsr    r5,error; 'e
    rts    pc

checkrp:
    cmp    r4,$')
    beq    1f
    jsr    r5,error; ')
    rts    pc
1:
    jsr    pc,readop
    rts    pc