2016 Update

Task/Factorial/MIPS-Assembly/factorial.mips

@@ -0,0 +1,48 @@
+##################################
+# Factorial; iterative           #
+# By Keith Stellyes :)           #
+# Targets Mars implementation    #
+# August 24, 2016                #
+##################################
+
+# This example reads an integer from user, stores in register a1
+# Then, it uses a0 as a multiplier and target, it is set to 1
+
+# Pseudocode:
+# a0 = 1
+# a1 = read_int_from_user()
+# while(a1 > 1)
+# {
+# a0 = a0*a1
+# DECREMENT a1
+# }
+# print(a0)
+
+.text ### PROGRAM BEGIN ###
+	### GET INTEGER FROM USER ###
+	li $v0, 5 #set syscall arg to READ_INTEGER
+	syscall #make the syscall
+	move $a1, $v0 #int from READ_INTEGER is returned in $v0, but we need $v0
+	              #this will be used as a counter
+
+	### SET $a1 TO INITAL VALUE OF 1 AS MULTIPLIER ###
+	li $a0,1
+
+	### Multiply our multiplier, $a1 by our counter, $a0 then store in $a1 ###
+loop:	ble $a1,1,exit # If the counter is greater than 1, go back to start
+	mul $a0,$a0,$a1 #a1 = a1*a0
+
+	subi $a1,$a1,1 # Decrement counter
+	
+	j loop # Go back to start
+	
+exit:
+	### PRINT RESULT ###
+	li $v0,1 #set syscall arg to PRINT_INTEGER
+	#NOTE: syscall 1 (PRINT_INTEGER) takes a0 as its argument. Conveniently, that
+	#      is our result.
+	syscall  #make the syscall
+
+	#exit
+	li $v0, 10 #set syscall arg to EXIT
+	syscall #make the syscall