YAPC::EU 2018 Glasgow Update!

Task/Factorial/MIPS-Assembly/factorial-2.mips

@@ -0,0 +1,42 @@
+#reference code
+#int factorialRec(int n){
+#    if(n<2){return 1;}
+#    else{ return n*factorial(n-1);}
+#}
+.data
+	n:	.word 5
+	result:	.word
+.text
+main:
+	la	$t0, n
+	lw	$a0, 0($t0)
+	jal	factorialRec
+	la	$t0, result
+	sw	$v0, 0($t0)
+	addi	$v0, $0, 10
+	syscall	
+	
+factorialRec:
+	addi	$sp, $sp, -8	#calling convention
+	sw	$a0, 0($sp)
+	sw	$ra, 4($sp)
+	
+	addi	$t0, $0, 2	#if (n < 2) do return 1
+	slt	$t0, $a0, $t0	#else return n*factorialRec(n-1)
+	beqz	$t0, anotherCall
+	
+	lw	$ra, 4($sp)	#recursive anchor
+	lw	$a0, 0($sp)
+	addi	$sp, $sp, 8
+	addi	$v0, $0, 1
+	jr	$ra
+	
+anotherCall:
+	addi	$a0, $a0, -1
+	jal	factorialRec
+
+	lw	$ra, 4($sp)
+	lw	$a0, 0($sp)
+	addi	$sp, $sp, 8
+	mul	$v0, $a0, $v0
+	jr	$ra