Calling the Dist Procedure

• The factorial can be written as

  • {[N(N-1)](N-2)}(N-3) ...
  • Dist(Dist(Dist(N,N,-1),N,-2),N,-3)

addi $v0,$0,1 # Initialize

beq $a0,$0,Done # 0! = 1

add $v0,$a0,$0 # Move argument

add $s0,$a0,$0 # Save arg register

addi $s1,$0,1 # Get 1 constant

add $a1,$a0,$0 # Move N

Loop: add $a0,$v0,$0 # Move running product

sub $a2,$0,$s1 # Negate and move

jal Dist # Go to subroutine

addi $s1,$s1,1 # Bump count

bne $s1,$a1,Loop# Continue until done

Done: add $a0,$s0,$0 # Put argument back

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