CS641 String Processing Example 1/31/11

Model for hw1 problem 1

countstring.s

# countstring.s: count chars in a string in data

# registers:

# t0 - pointer to string

# t1 - count of chars

# t2 - current char

.globl main

.globl str2count

main: la $t0, str2count # point to string

li $t1, 0 # count = 0

loop: lb $t2, 0($t0) # load byte of string

beq $t2, $0, done # check if byte = 0

addi $t1,$t1,1 # inc count

addi $t0, $t0, 1 # inc pointer

j loop # loop back

done: move $a0, $t1 # count to print

li $v0, 1 # print int

syscall

jr $ra # return

.data

str2count: .asciiz "abcdefg"