; WINDLX Ex.3: Factorial
; (c) 1991 Guenther Raidl
; Modified: 1992 Maziar Khosravipour
; Program begin at symbol main
; requires module INPUT
; read a number from stdin and calculate the factorial (type: double)
; the result is written to stdout
;---
 .data
Prompt: .asciiz "An integer value >1 : "
PrintfFormat: .asciiz "Factorial = %g\n\n"
 .align 2
PrintfPar: .word PrintfFormat
PrintfValue:.space 8
 .text
 .global main
main:
 ;--- Read value from stdin into R1
 addi r1,r0,Prompt
 jal InputUnsigned
 ;--- init values
 movi2fp f10,r1 ;R1 -> D0 D0..Count register
 cvti2d f0,f10
 addi r2,r0,1 ;1 -> D2 D2..result
 movi2fp f11,r2
 cvti2d f2,f11
 movd f4,f2 ;1-> D4 D4..Constant 1
 ;--- Break loop if D0 = 1
Loop: led f0,f4 ;D0<=1 ?
 bfpt Finish
 ;--- Multiplication and next loop
 multd f2,f2,f0
 subd f0,f0,f4
 j Loop
Finish: ;--- write result to stdout
 sd PrintfValue,f2
 addi r14,r0,PrintfPar
 trap 5
 ;--- end
 trap 0