Category : Assembly Language Source Code
Archive   : ASM_SUBR.ZIP
Filename : FPTMUL

;-------------------------fptmul routine begins--------------------------+
; from BLUEBOOK OF ASSEMBLY ROUTINES FOR IBM PC & XT.
; page : 85
;
; NAME FPTMUL
; ROUTINE FOR MULTPLICATION OF TEMPORARY FLOATING POINT NUMBER BY 10
;
; FUNCTION: This routine multiplies a temporary binary floating point
; number by 10. The result is not normalized.
;
; INPUT: Upon entry DS:DI points to a temporary binary floating point
; number.
;
; OUTPUT: Upon exit DS:DI points to a temporary binary floating
; point number. This number is not normalized.
;
; REGISTERS USED: AX, CX, DX and DI are modified. DI must point to
; the input.
;
; SEGMENTS REFERENCED: The data segment must contain the temporary
; floating point number.
;
; ROUTINES CALLED: None
; SPECIAL NOTES: This is a near procedure needed by FPIN.
;
; ROUTINE TO MULTIPLY TEMP FLOATING POINT NUMBER BY 10
;
fptmul proc near
;
mov cx,5 ; for a count of five
mov dx,0 ; carry of zero
;
fptmul1:
push cx ; save count
mov ax,dx ; previous carry
xchg ax,[di] ; switch with 16-bit digit
mov cx,10 ; multiplier of 10
mul cx ; multiply
add [di],ax ; add into carry in place
add di,2 ; next 16-bit digit
pop cx ; restore count
loop fptmul1
;
ret ; return
;
fptmul endp
;-------------------------fptmul routine ends---------------------------+