# fact4main.mips
# Read a number n from standard input, then print n!
# (n factorial) on standard output.  Uses fact4
# to calculate the factorial.

.globl main

main:   trap 5            # Get integer n into $2

        addi $30, $30, -4 # Allocate space on stack
        sw $2, 0($30)     # Push parameter on stack from $2
        jal fact4         # Calculate n! in $1
        addi $30, $30, 4  # De-allocate space on stack.
                          # Not actually needed in this
                          # context, but usually mandatory

        add $4, $0, $1    # Copy result from $1 to $4
        trap 1            # Print result (in $4)

        addi $4, $0, 10        
        trap 101          # Print newline character

        trap 10           # Quit program