# File:        hmwk02-1-soln.asm
# Written by:  Archana Chidanandan, Dec. 16, 2003
#
# Given two values "a" and "b" in memory, to obtain the product "c", without
# using MIPS mult, multu, mul, mulo or muluo instructions. The program must use
# a loop. The product must be calculated using a procedure.
#
	 	.text
		.globl main
main:
		la	$s0,  A		
		lw 	$s0, 0($s0)	# Read the value of “A” from memory

		la	$t1, B
		lw	$s1, 0($t1)	# Read the value of “B” from memory.

		move	$a0, $s0 	# Copy the arguments "A" and "B" into the argument 					# registers
		move	$a1, $s1
		jal 	Product		# Call procedure "Product"
		move 	$t4, $v0	# Store return value "c" in temporary register.	

		la	$t3, C
		sw	$t4, 0($t3)	# Store the value of “c” in memory

		li 	$v0, 10
		syscall			# Ready to quit


Product:				# Procedure to determine the product
		move	$t0, $a0	# Move the paraments into temporary registers.
		move	$t1, $a1

		li	$t3, 0		#  i = 0 (to keep track of the value “b”
		li	$t4, 0		#  c = 0 (initialize the result to 0)

loop:
		beq	$t3, $t1, done  # while (i is not equal to b ) continue adding
					# a to c.
		add	$t4, $t4, $t0	# c= c + a;
		addi	$t3, $t3, 1	# i = i + 1
		j loop

done:
		move	$v0, $t4	# Move return value "c" to the return value 							# register.
		jr 	$ra		# Return to the calling procedure
		
		
		.data
A:	.word	5
B:	.word	20
C:	.word	0