# fact0.mips
# Calculate 4! (4 factorial).
#
# Register Usage:
# $1 - Accumulates result
# $2 - Counter of current value to multiply

.globl main

main:   addi $2, $0, 4     # Place the number 4 in $2
        addi $1, $0, 1     # Initialize result to 1
        beq $0, $2, done   # If none left, finish
loop:   mult $1, $2        # Multiply result by counter
        mflo $1            # Get product from Lo register
        addi $2, $2, -1    # Decrement counter
        bne $0, $2, loop   # If more to do, loop
done:   add $4, $0, $1     # Copy result (24) to $4
        trap 10            # Exit program