Question

Write a macro for calculating the dot product of two vectors in 80x86 assy language

; computes the dot product of two vectors
dot_product MACRO x1, y1, z1, x2, y2, z2

ENDM

Answer 1

dot_product MACRO x1,y1,z1,x2,y2,z2

push cx # ax and cx is pushed to the stack so that its value in the main program is not altered

push ax

mov al,x1

mov cl,x2

mul cl

add bx,ax #register bx is used to store the sum

mov al,y1

mov cl,y2

mul cl

add bx,ax

mov al,z1

mov cl,z2

mul cl

add bx,ax

dis

pop cx #initial values of ax and cx are brought back

pop ax

ENDM

dis MACRO #This MACRO is to display the result on the screen

mov ax,bx

add ax,3030h #3030h is added so the the ascii value of the number is obtained

mov cx,ax

mov dl,ah

mov ah,2h #interrupt to print a value on the screen

int 21h

mov dl,cl

mov ah,2h

int 21h

ENDM