;; File:        leftshift.asm
;; Description: ... fill this in
;; Author:      ... fill this in
;; Date:        ... fill this in


                .ORIG     x3000
                BR MAIN

;; Input variables
TOSHIFT         .BLKW         1               ; Input word to left shift
A               .BLKW         1               ; Input variable A, A >= B
B               .BLKW         1               ; Input variable B, B <= A
LS_AMOUNT       .BLKW         1               ; Input to subroutine LEFT_SHIFT
;
;; Output variables
SHIFTED         .BLKW         1               ; Result after shifiting left
R_DIFF          .BLKW         1               ; Result computed by COMPUTE_DIFF

;; Function:     main
;; ... fill in description

MAIN            AND R1,R1,#0                  ; R1 = 0
                JSR COMPUTE_DIFF              ; Call subroutine COMPUTE_DIFF
                ; ... load value of R_DIFF and store in LS_AMOUNT
                JSR LEFT_SHIFT                ; Call subroutine LEFT_SHIFT
                HALT                          ; Program complete
;
;; Subroutine: COMPUTE_DIFF
;; Input: A, B
COMPUTE_DIFF    ;.... complete rest
                RET                           ; return from subroutine
;
;; Subroutine:  LEFT_SHIFT
;; Input:       TOSHIFT, LS_AMOUNT
LEFT_SHIFT    ;.... complete rest
                RET                           ; return from subroutine
;
                .END