MASM assembly language(x86) macros (CBW,LOOP, PTR)

Question

Suppose your assembler does not have the operations CBW, LOOP and PTR, how can you design a macro for each of theses?

Example:

    MCBW macro
    move AX,0
    div AX,CH
    endm

Answer 1

Loop macro:

;//---------------------------------------------------------------------------
myLoop MACRO myLabel:REQ
;//---------------------------------------------------------------------------

    dec ecx
    jnz myLabel

ENDM

in proc example:

mov ecx, 5
mov eax, 0
ANY_LOOP:
   inc eax
myLoop ANY_LOOP

CBW macro:

;//---------------------------------------------------------------------------
myCBW MACRO
;//---------------------------------------------------------------------------
    mov ebx, eax
    and eax, 080h
    shl ax, 1
    xchg ah, al
    mov ecx, 0FFFFh
    mul ecx
    mov al, bl

ENDM

in proc example:

mov eax, 8Fh
myCBW

PTR macro:

;//---------------------------------------------------------------------------
myPointer MACRO source:REQ
;//---------------------------------------------------------------------------
    exitm <[source]>

ENDM

in proc example:

.data
    number  DWORD 5

.code
    main PROC

    mov eax, myPointer(number)