# 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