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[unix-history] / usr / src / libfpsim / fp1.s

/ fp1 -- floating point simulator

rti     = 2
bpt     = 3

m.ext = 200             / long mode bit
m.lngi = 100            / long integer mode

.globl  fptrap
.globl  ac0, ac1, ac2, ac3

fptrap:
       dec     reenter
       bge     1f
       4               / reentered!
1:
       mov     (sp)+,spc
       mov     (sp)+,sps
       mov     r0,sr0
       mov     $sr1,r0
       mov     r1,(r0)+
       mov     r2,(r0)+
       mov     r3,(r0)+
       mov     r4,(r0)+
       mov     r5,(r0)+
       mov     sp,(r0)+
       mov     (r0),r5         / pc
       mov     -(r5),r5        / trapped instruction

again:
       sub     $8,sp           / room for double push
       clr     trapins
       mov     r5,r4
       bic     $7777,r4
       cmp     r4,$170000
       beq     1f
       jmp     badins
1:
       bic     $100000,fpsr    / clear fp error
       bic     $170000,r5
       mov     r5,r4
       bit     $7000,r4
       bne     class3
       bit     $700,r4
       bne     class2
       cmp     r4,$12
       blos    1f
       jmp     badins
1:
       asl     r4
       jmp     *1f(r4)

       .data
1:
       i.cfcc          / 170000
       i.setf          / 170001
       i.seti          / 170002
       badins
       badins
       badins
       badins
       badins
       badins
       i.setd          / 170011
       i.setl          / 170012
       .text

class2:
       cmp     r5,$400
       bge     1f
       jsr     r1,fsrc; mod0rx; mod242
       br      2f
1:
       jsr     r1,fsrc; mod0f; mod24f
2:
       mov     r3,r5
       asl     r4
       asl     r4
       clrb    r4
       swab    r4
       asl     r4
       jsr     pc,*1f(r4)
       jmp     sret

       .data
1:
       badins          / 1700xx
       i.ldfps         / 1701xx
       i.stfps         / 1702xx
       badins          / 1703xx - stst
       i.clrx          / 1704xx
       i.tstx          / 1705xx
       i.absx          / 1706xx
       i.negx          / 1707xx
       .text

class3:
       cmp     r5,$5000
       blt     1f
       mov     r5,r2
       clrb    r2
       cmp     r2,$6400
       blt     2f
       sub     $1400,r2
2:
       cmp     r2,$5000
       bne     2f
       jsr     r1,fsrc; mod0rx; mod242
       br      3f
2:
       cmp     r2,$5400
       bne     2f
       jsr     r1,fsrc; mod0ra; mod24i
       br      3f
2:
       jsr     r1,fsrc; mod0f; mod24d
       br      3f
1:
       jsr     r1,fsrc; mod0f; mod24f
3:
       jsr     pc,freg
       mov     r2,r5
       clrb    r4
       swab    r4
       asl     r4
       jsr     pc,*1f(r4)
       br      sret

       .data
1:
       badins          / 1700xx
       badins          / 1704xx
       i.mulx          / 1710xx
       i.modx          / 1714xx
       i.addx          / 1720xx
       i.ldx           / 1724xx
       i.subx          / 1730xx
       i.cmpx          / 1734xx
       i.stx           / 1740xx
       i.divx          / 1744xx
       i.stexp         / 1750xx
       i.stcxj         / 1754xx
       i.stcxy         / 1760xx
       i.ldexp         / 1764xx
       i.ldcjx         / 1770xx
       i.ldcyx         / 1774xx
       .text

i.cfcc:
       mov     fpsr,r0
       bic     $!17,r0
       mov     r0,sps
       br      ret

i.setf:
       bic     $m.ext,fpsr
       br      ret

i.setd:
       bis     $m.ext,fpsr
       br      ret

i.seti:
       bic     $m.lngi,fpsr
       br      ret

i.setl:
       bis     $m.lngi,fpsr
       br      ret

badins:
       inc     trapins
       br      ret1

sret:
       mov     $fpsr,r0
       bic     $17,(r0)
       tstb    1(r5)
       bpl     1f
       bis     $10,(r0)
       br      ret
1:
       bne     ret
       bis     $4,(r0)

ret:
       mov     ssp,sp
       mov     *spc,r5
       cmp     r5,$170000
       blo     ret1
       add     $2,spc
       jbr     again                   / if another fp, save trap

ret1:
       mov     $sr1,r0
       mov     (r0)+,r1
       mov     (r0)+,r2
       mov     (r0)+,r3
       mov     (r0)+,r4
       mov     (r0)+,r5
       mov     (r0)+,sp
       mov     sr0,r0
       mov     sps,-(sp)
       mov     spc,-(sp)
       tst     trapins
       bne     1f
       inc     reenter
       rti
1:
       bpt

freg:
       mov     r5,r2
       bic     $!300,r2
       asr     r2
       asr     r2
       asr     r2
       add     $ac0,r2
       rts     pc

fsrc:
       mov     r5,r3
       bic     $!7,r3                  / register
       asl     r3
       add     $sr0,r3
       mov     r5,r0
       bic     $!70,r0                 / mode
       asr     r0
       asr     r0
       jmp     *1f(r0)

       .data
1:
       mod0
       mod1
       mod2
       mod3
       mod4
       mod5
       mod6
       mod7
       .text

mod24f:
       mov     $4,r0
       bit     $m.ext,fpsr
       beq     1f
       add     $4,r0
1:
       rts     pc

mod24d:
       mov     $8,r0
       bit     $m.ext,fpsr
       beq     1f
       sub     $4,r0
1:
       rts     pc

mod242:
       mov     $2,r0
       rts     pc

mod24i:
       mov     $2,r0
       bit     $m.lngi,fpsr
       beq     1f
       add     $2,r0
1:
       rts     pc

mod0:
       jmp     *(r1)+

mod0f:
       sub     $sr0,r3                 / get fp ac
       cmp     r3,$6*2
       bhis    badi1
       asl     r3
       asl     r3
       add     $ac0,r3
       tst     (r1)+
       rts     r1

mod0ra:
       bit     $m.lngi,fpsr
       bne     badi1

mod0r:
       cmp     r3,$ssp
       bhis    badi1
mod0rx:
       tst     (r1)+
       rts     r1

mod1:
       cmp     r3,$spc
       beq     badi1
       mov     (r3),r3
       br      check

mod2:
       mov     (r3),-(sp)
       jsr     pc,*2(r1)
       cmp     r3,$spc
       bne     1f
       mov     $2,r0
       mov     *(r3),pctmp
       mov     $pctmp,(sp)
1:
       add     r0,(r3)
       mov     (sp)+,r3
       br      check

mod3:
       mov     *(r3),-(sp)
       add     $2,(r3)
       mov     (sp)+,r3
       br      check

mod4:
       cmp     r3,$spc         / test pc
       beq     badi1
       jsr     pc,*2(r1)
       sub     r0,(r3)
       mov     (r3),r3
       br      check

mod5:
       cmp     r3,$spc
       beq     badi1
       sub     $2,(r3)
       mov     *(r3),r3
       br      check

mod6:
       mov     *spc,-(sp)
       add     $2,spc
       add     (r3),(sp)
       mov     (sp)+,r3
       br      check

mod7:
       jsr     r1,mod6; ..; ..
       mov     (r3),r3
       br      check

badi1:
       jmp     badins

check:
       bit     $1,r3
       bne     badi1
       cmp     (r1)+,(r1)+
       rts     r1

setab:
       mov     $asign,r0
       jsr     pc,seta
       mov     r3,r2
       mov     $bsign,r0

seta:
       clr     (r0)
       mov     (r2)+,r1
       mov     r1,-(sp)
       beq     1f
       blt     2f
       inc     (r0)+
       br      3f
2:
       dec     (r0)+
3:
       bic     $!177,r1
       bis     $200,r1
       br      2f
1:
       clr     (r0)+
2:
       mov     r1,(r0)+
       mov     (r2)+,(r0)+
       bit     $m.ext,fpsr
       beq     2f
       mov     (r2)+,(r0)+
       mov     (r2)+,(r0)+
       br      3f
2:
       clr     (r0)+
       clr     (r0)+
3:
       mov     (sp)+,r1
       asl     r1
       clrb    r1
       swab    r1
       sub     $200,r1
       mov     r1,(r0)+        / exp
       rts     pc

norm:
       mov     $areg,r0
       mov     (r0)+,r1
       mov     r1,-(sp)
       mov     (r0)+,r2
       bis     r2,(sp)
       mov     (r0)+,r3
       bis     r3,(sp)
       mov     (r0)+,r4
       bis     r4,(sp)+
       bne     1f
       clr     asign
       rts     pc
1:
       bit     $!377,r1
       beq     1f
       clc
       ror     r1
       ror     r2
       ror     r3
       ror     r4
       inc     (r0)
       br      1b
1:
       bit     $200,r1
       bne     1f
       asl     r4
       rol     r3
       rol     r2
       rol     r1
       dec     (r0)
       br      1b
1:
       mov     r4,-(r0)
       mov     r3,-(r0)
       mov     r2,-(r0)
       mov     r1,-(r0)
       rts     pc