# CSCI 424, Homework 2
# switch to the Data segment
.data
# global data is defined here
# Don't forget the backslash-n (newline character)
Homework:
.asciiz "CSCI 424 Homework 2\n"
Name_1:
.asciiz "Adam\n"
Name_2:
.asciiz "Carpenter\n"
# switch to the Text segment
.text
# the program is defined here
.globl main
main:
# Whose program is this?
la $a0, Homework
jal Print_string
la $a0, Name_1
jal Print_string
la $a0, Name_2
jal Print_string
# int i, n = 2;
# for (i = 0; i <= 16; i++)
# {
# ... calculate n from i
# ... print i and n
# }
# register assignments
# $s0 i
# $s1 n
# $a0 argument to Print_integer, Print_string
# add to this list if you use any other registers
# ---My New Registers---
# $s2 bit
# $t0 temp (temporary)
# ----------------------
# initialization
li $s1, 2 # n = 2
# for (i = 0; i <= 16; i++)
li $s0, 0 # i = 0
bgt $s0, 16, bottom
top:
# calculate n from i
# Your part starts here
# ------Solution in C code--------
# n = 0;
# int bit;
# for (bit = 0; bit < 32; bit++) {
# temp = i >> bit;
# temp = temp & 1;
# n = n + temp;
# }
# --------------------------------
li $s1, 0 # n = 0
li $s2, 0 # bit = 0
bitloop:
srav $t0, $s0, $s2 # temp = i >> bit
andi $t0, $t0, 1 # temp = temp & 1
add $s1, $s1, $t0 # n = n + temp
add $s2, $s2, 1 # bit++
blt $s2, 32, bitloop # if bit < 32 goto bitloop
# Your part ends here
# print i and n
move $a0, $s0 # i
jal Print_integer
la $a0, sp # space
jal Print_string
move $a0, $s1 # n
jal Print_integer
la $a0, cr # newline
jal Print_string
# for (i = 0; i <= 16; i++)
add $s0, $s0, 1 # i++
ble $s0, 16, top # i <= 16
bottom:
la $a0, done # mark the end of the program
jal Print_string
jal Exit # end the program, no explicit return status
# switch to the Data segment
.data
# global data is defined here
sp:
.asciiz " "
cr:
.asciiz "\n"
done:
.asciiz "All done!\n"
# - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
# Wrapper functions around some of the system calls
# See P&H COD, Fig. A.9.1, for the complete list.
# switch to the Text segment
.text
.globl Print_integer
Print_integer: # print the integer in register a0
addi $v0, $zero, 1
syscall
jr $ra
.globl Print_string
Print_string: # print the string whose starting address is in register a0
addi $v0, $zero, 4
syscall
jr $ra
.globl Exit
Exit: # end the program, no explicit return status
addi $v0, $zero, 10
syscall
jr $ra
.globl Exit2
Exit2: # end the program, with return status from register a0
addi $v0, $zero, 17
syscall
jr $ra
