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.globl factorial 
 
.text 
factorial: 
        lda         $sp,-0x10($sp) 
        stq         $ra,0x8($sp) 
        stq         $s0,0x0($sp) 
        bis         $zero,$a0,$s0 
        zapnot      $s0,0xf,$a0 
        cmpule      $a0,0x1,$a0 
        bne         $a0,1f 
        br          $zero,2f 
1:      lda         $v0,0x1($zero) 
        br          $zero,3f 
2:      lda         $v0,-0x1($zero) 
        addl        $s0,$v0,$v0 
        zapnot      $v0,0xf,$a0 
        bsr         $ra,factorial 
        mull        $s0,$v0,$v0 
3:      ldq         $s0,0x0($sp) 
        ldq         $ra,0x8($sp) 
        lda         $sp,0x10($sp) 
        ret         $zero,($ra),0x1