usr/src/cmd/as/as24.s

/
/

/ a4 -- pdp-11 assembler pass 2

oset:
        mov     r2,-(sp)
        mov     r3,-(sp)
        mov     (r5)+,r3
        mov     r1,r2
        bic     $!777,r1
        add     r3,r1
        add     $8,r1
        mov     r1,(r3)+        / next slot
        mov     r3,r1
        add     $1006,r1
        mov     r1,(r3)+        / buf max
        mov     r0,(r3)+
        mov     r2,(r3)+        / seek addr
        mov     (sp)+,r3
        mov     (sp)+,r2
        rts     r5

putw:
        mov     r1,-(sp)
        mov     r2,-(sp)
        mov     (r5)+,r2
        mov     (r2)+,r1        / slot
        cmp     r1,(r2)         / buf max
        bhis    1f
        mov     r0,(r1)+
        mov     r1,-(r2)
        br      2f
1:
        tst     (r2)+
        mov     r0,-(sp)
        jsr     r5,flush1
        mov     (sp)+,r0
        mov     r0,*(r2)+
        add     $2,-(r2)
2:
        mov     (sp)+,r2
        mov     (sp)+,r1
        rts     r5

flush:
        mov     (r5)+,r2
        cmp     (r2)+,(r2)+
flush1:
        mov     (r2)+,0f
        mov     (r2)+,r1
        mov     r1,0f+2         / seek address
        mov     fout,r0
        sys     indir; 9f
        .data
9:      sys     lseek; 0:..; ..; 0
        .text
        bic     $!777,r1
        add     r2,r1           / write address
        mov     r1,0f
        mov     r2,r0
        bis     $777,-(r2)
        add     $1,(r2)         / new seek addr
        adc     -(r2)
        cmp     -(r2),-(r2)
        sub     (r2),r1
        neg     r1
        mov     r1,0f+2         / count
        mov     r0,(r2)         / new next slot
        mov     fout,r0
        sys     indir; 9f
        jes     wrterr
        .data
9:      sys     write; 0:..; ..
        .text
        rts     r5

wrterr:
        mov     $1,r0
        sys     write; 9f; 8f-9f
        jmp     saexit
9:      <as: write error on output\n>; 8:

readop:
        mov     savop,r4
        beq     1f
        clr     savop
        rts     pc
1:
        jsr     pc,getw1
        cmp     r4,$200
        blo     1f
        cmp     r4,$4000
        blo     2f
        add     $usymtab-4000,r4
        rts     pc
2:
        add     $symtab-1000,r4
1:
        rts     pc

getw:
        mov     savop,r4
        beq     getw1
        clr     savop
        rts     pc
getw1:
        dec     ibufc
        bgt     1f
        movb    fin,r0
        sys     read; inbuf; 512.
        bes     3f
        asr     r0
        mov     r0,ibufc
        bne     2f
3:
        mov     $4,r4
        sev
        rts     pc
2:
        mov     $inbuf,ibufp
1:
        mov     *ibufp,r4
        add     $2,ibufp
        rts     pc