# Sum an array of integers.  
# Leave the result in Sum.
# place the value in r4 to be printed

# Registers
#   $t1 -- true if done
#   $t2 -- current address in array
#   $t3 -- last address of array
#   $t4 -- running sum	
#   $t5 -- temp to get value from memory
.text
.globl main

main:   add     $t4, $0, $0      # Initialize $t4
        la      $t2, First       # get first address
        la	    $t3, Last        # get last address
        
loop:   slt     $t1, $t3, $t2      # test if done
        bne     $t1, $0, done    # if yes, branch
        lw      $t5, 0($t2)       # load array value 
        add     $t4, $t4, $t5      # add to sum
        addi    $t2, $t2, 4       # inc array pointer
        j       loop            # do it again

done:   
        sw      $t4, Sum
	  lw      $a0, Sum
        li      $v0, 1          # print contents of $t4 (This will be the sum)
	  syscall
        li      $v0, 10         # Quit
	  syscall
# Data
.data
First:  .word   10
        .word   20
        .word    1
        .word   15
        .word    3
        .word   10
Last:   .word    5
Sum:    .word    0     # should be 64