Creating (and accessing) an array in MIPS

Question!

I'm trying to create an array in MIPS Assembly, and then add all the elements together. However, when I try to assemble the following, it says

Error in read_array line 1 position 7: ".word" directive cannot appear in text segment Assemble: operation completed with errors.

Here's my assembly:

list: .word 3, 2, 1, 0, 1, 2
li $t0, 0x00000000  #initialize a loop counter to $t0
li $t4, 0x00000005  #last index of array
li $t3, 0x00000000  #this will hold our final sum
la $t1, list  #the address of list[0] is in $t1

loop: addi $t0, $t0, 0x00000001 #index++
  add $t5, $t0, $t0 #array index X2
  add $t5, $t0, $t0 #array index X2 again
  add $t6, $t5, $t1 #4x array index in $t6

  lw $t2, 0($t6)   #load list[index] into $t2
  add $t3, $t3, $t2 #$t3 = $t3 + $t2
  beq $t0, $t4, end
  j loop

end:

Thanks!

By : hodgesmr


Answers

The error is telling you you can't put data (.word 3, 2) in the code segment. "Text segment" is an old style term meaning "code segment" http://en.wikipedia.org/wiki/Code_segment

The assembler wants you to declare a data segment and put the array there. I've never done Mips assembler, but I would expect it to be something like this

.data
list: .word 3, 2, 1, 0, 1, 2

.text
start:
li $t0, 0x00000000  #initialize a loop counter to $t0
li $t4, 0x00000005  #last index of array
li $t3, 0x00000000  #this will hold our final sum
la $t1, list  #the address o


You have to put this line:

list: .word 3, 2, 1, 0, 1, 2

Into the .data section. Check this quick tutorial.



This video can help you solving your question :)
By: admin