math_expression.asm

%include "rw32-2017.inc"
 
section .data
    a dw -5;5
    b dw -2;2
    c dw 10;10
    
    d dw 0
 
section .text   
main:
    mov ebp, esp; for correct debugging
    ;mov edx, 0
    ;mov eax, 0
    
    ;mov bl, -3200
    ;mov al, 4
 
    ;imul bl; vysledek po provedeni teto instrukce bude v registrech EDX:EAX tzn. EDX:EAX=EBX*EAX  
    
    ;xor dx, dx ;vynuluje registr edx, protoze delenec bude pouze v registru eax
    ;mov ax, 20 ; delenec v eax
    ;mov bx, 3; delitel
    ;div bx; celociselny vysledek se ulozi do registru AX a zbytek po deleni do registru DX
    
    ; d = (4*a + 100*b) / c
    
    mov ax, [a]
    mov bx, word 4
    imul bx ; a * 4
    
    add [d], ax ; d += a * 4
    
    mov ax, [b]
    mov bx, word 100
    imul bx ; b * 100
    
    add [d], ax ; d += b * 100
    
    mov ax, [d]
    cwd
    mov bx, [c]
    idiv bx ; d /= c
    
    mov [d], ax
    
ret