TITLE GCD.asm



INCLUDE Irvine32.inc



PrepareMap PROTO,
    string: PTR BYTE,
    map: PTR BYTE



CharacterSearch PROTO,
        map: PTR BYTE,
        char: BYTE

.data
stringMap byte 32 dup(0)
testString byte "hello, assembly language programming!",0
msg1 byte " is not in the string.",0
msg2 byte " is in the string.",0

;Code test driver
.code
    main PROC





    INVOKE PrepareMap, addr testString, addr stringMap



    INVOKE CharacterSearch, addr stringMap, 'h'



    exit
    main ENDP




    PrepareMap PROC USES ECX EBX EAX EDX ESI EDI EBP, string: PTR BYTE, map: PTR BYTE
    mov esi, string
    mov edi, map
    mov ebp, 0

ForLoop:

    cmp ebp, 32
    JGE L9

    LeftSide:

        mov al, [esi]
        shr al, 3
        add [edi], al

    RightSide:
        mov cl, [esi]
        AND cl, 7
        mov bl, 1
        shl bl, cl

    OrStatement:
        OR [edi], bl
        inc ebp

        JMP ForLoop




    L9:
        ret
    PrepareMap Endp




    CharacterSearch PROC map: PTR BYTE, char: BYTE

    LeftSide:
        ;mov al, char
        ;call WriteChar
        mov edi, map
        mov cl, char
        shr cl, 3
        mov [edi], cl

    RightSide:
        mov cl, char
        AND cl, 7
        mov al, 1
        shl al, cl

    AndStatement:
        mov bl, [edi]
        AND bl, al


    IfStatement:
        cmp bl, 0
        JE NotIn
        mov edx, offset msg2
        call WriteString
        JMP L9


    NotIn:
        mov edx, offset msg1
        call WriteString

    L9:
    ret
    CharacterSearch endp


    END main