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Length: 1536 (0x600)
Types: TextFile
Names: »MPNORM.SRC«
└─⟦c9df7130d⟧ Bits:30005915 Pascal MT+ Release 5.2 (Jet-80)
└─ ⟦this⟧ »MPNORM.SRC«
;MULT.PRECISION ADD AND SUB. AND NORMALIZE A FLOATING POINT NUMBER ; NAME MPNORM ENTRY MPADD,MPSUB,FNORM EXT FPERR INCLG ; ; CONSET : A SUBROUTINE THAT SETS THE RELEVANT BIT(S) IN A SET TO INDICATE ; THE PRESENCE OF THAT ELEMENT IN THE SET. (hl) -> (de) ; mpadd: xra a ;clear carry push b ;save b mvi b,fracln ;add all bytes mpadd1: ldax d ;get byte from op1 adc m ;add byte from op2 stax d ;store it inx h ;bump pointers inx d djnz mpadd1 ;any more? pop b ;restore b ret ;no, return mpsub: xra a ;clear carry push b ;save b mvi b,fracln mpsub1: ldax d ;get byte from op1 sbb m ;subtract byte from op2 stax d ;store it inx h ;bump pointers inx d djnz mpsub1 ;any more? pop b ;restore b ret ;no, return ; ; normalize a floating point number ; fnorm: xra a ;clear acc mov scr1(x),a ;set sign indicator to +ve num bit sign,msb(y) ;test sign of number jrz posit ;it's positive inr scr1(x) ;negative...set sign indicator res sign,msb(y) ;and negate fraction posit: zchk y ;check number = 0 jrnz fpanz ;..fpacc <> 0 mvi exp(y),0 ;set exp = 0 ret fpanz: bit sign-1,msb(y) ;check msb jrnz allrot ;all rotated rotate y,left ;rotate left until msb is a one dcr exp(y) ;adjust exponent jv fperr ;floating point error jr fpanz ;try again allrot: dcr scr1(x) ;check sign indicator rnz ;positive number, return bset sign,msb(y) ;negate number and return ret ; «eof»