Question

Assembly Language

Given the following psuedocode, write the appropriate prolog in assembly for the method mysub usin frame-based linkage. main) 9) int a; a = mysub( 6 ); print( a ); int mysub( int arg) int b,c; b= arg*2; c=b+7; return c

Answer 1

9)

1 .text 2 add Ste,zero,6 // unction 3 jal mySub //call function 4 move $a0,St1 //store return value to ae 5 li Sve,1 //call print int method 6 syscall 7 li Sve,10 //stop execution 8 syscall 9 mySub //function 10 mul Ss0,$tø,2 // b-arg 2 11 add St1,Ss0,7 //cb+7l 12 jr śra /set parameter for f

OUTPUT: 19

Source code ::

.text
add $t0,$zero,6 //set parameter for function
jal mySub //call function
move $a0,$t1 //store return value to a0
li $v0,1 //call print int method
syscall  
li $v0,10 //stop execution
syscall
mySub : //function
mul $s0,$t0,2 // b = arg*2
add $t1,$s0,7 //c = b+7
jr $ra