I am new to programming in MIPS and have been having trouble with one problem. I am working to solve the equation f = 5 - a[3] + g * h
For:g=3,
h=5, and
a[0]= 10, a[1]= 8, a[2]= 6, a[3]=4 .... a[4]=2
Here is the code I already have:
.data
g: .word 3 #
h: .word 5
a: .word 10,8,6,4,2,0
f: .space 4
mes1: .ascii "Problem 3:"
newL: .ascii "\n"
.text
main:
lw $t0, g #t0= g
lw $t1, h #t1= h
mul $t2, $t0, $t1 #t2= g *h
add $t3, $zero, 4 #t3= 4
mul $t4, $t0, $t3 #t4= 3 * 4
lw $t5, 0($t4)
add $t5, $t5, $t2 #t5= a[3] + (g * h)
sub $t5, $t0, $t5 #t5= 5 - [a[3] + g * h]
sw $t5, f #f= t5
la $a0, mes1 #loads addr for label in a0
li $v0, 4 #prepares to output as a string
syscall #prints label
la $a1, f #loads addr for a in a1
li $v0, 1 #prepares to output as an int
syscall #prints a
li $v0, 10 #call to terminate program
syscall #terminates program
When run with spim I get the following output:
spim -file problem3.asm
SPIM Version 8.0 of January 8, 2010
Copyright 1990-2010, James R. Larus.
All Rights Reserved.
See the file README for a full copyright notice.
Loaded: /usr/lib/spim/exceptions.s
Exception occurred at PC=0x00400040
Bad address in data/stack read: 0x0000000c
Exception 7 [Bad data address] occurred and ignored
Problem 3:
268501028
I currently get a bad data address exception and a random large number as output. It would be great if someone from SO could tell me what I am doing wrong, why I am getting junk output and what I need to change. Thanks in advance