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;* SubLong - Subtracts a double-word (long) integer from another.
;*
;* Shows:   Instructions -  sub     sbb
;*
;* Params:  Long1 - First integer
;*          Long2 - Second integer
;*
;* Return:  Difference as long integer
 
SubLong PROC,
        Long1:SDWORD, Long2:SDWORD
 
        mov     ax, WORD PTR Long1[0]   ; AX = low word, long1
        mov     dx, WORD PTR Long1[2]   ; DX = high word, long1
        sub     ax, WORD PTR Long2[0]   ; Subtract low word, long2
        sbb     dx, WORD PTR Long2[2]   ; Subtract high word, long2
        ret                             ; Result returned as DX:AX
 
SubLong ENDP
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