Body of `fact()`

#  int fact( int n )
#  {
#    if ( n<=1)
#      return 1;
#    else
#      return n*fact(n-1);
#  }
         .text
         .globl  fact
fact:
                                  # prolog        
         . . . . . .
                                  # body of subroutine
         move    $s1,$a0          # save argument in $s1
         li      $t1,1            # get a 1
         bgt     $s1,$t1,recurse  # if ( n<=1)
         li      $v0,1            #   return 1
         
         b        

recurse:                          # else
                                  #   return n*fact(n-1);
         . . . . . . 
epilog:                           # epilog
                                  #   1. Return value is already in $v0        
         . . . . . .
         jr      $ra              #

The argument in $a0 is saved in register $s1 because later on $a0 may be altered. (Since this subroutine uses $s1 the contents of $s1 is saved on the stack in the prolog).

The if statement checks if the argument (in $a0) is 1 or less. If so, it loads register $v0 with the value to return to the caller, one. Otherwise, the other branch is taken and the recursive call is performed.

Answer:

Body of `fact()`

QUESTION 25:

Answer:

Body of fact()

QUESTION 25:

Body of `fact()`