/* --------------------------------------------------
   Demo file for sumSquares function
   -------------------------------------------------- */
        .global main, Stop, CodeEnd, DataStart, DataEnd

	.global Pause, sumSquares

/* --------------------------------------------------
   Begin of the program instructions
   -------------------------------------------------- */
	.text
main:
        /* =====================================================
           Statement: z = sumSquares(4,7)
           ===================================================== */
        /* -------------------------------------------------
	   Pass parameters in regs r0 and r1
           ------------------------------------------------- */

        /* -----------------------------------------------------------------
	   Save return value (in r0) to variable z (z = sumSquares(..))
           ----------------------------------------------------------------- */

Pause:
        /* =====================================================
           Statement: z = sumSquares(4,7)
           ===================================================== */
        /* -------------------------------------------------
	   Pass parameters 4 and 7 in regs r0 and r1
           ------------------------------------------------- */

        /* -----------------------------------------------------------------
	   Save return value (in r0) to variable z (z = sumSquares(..))
           ----------------------------------------------------------------- */


Stop:
	nop			   // Stop point of main( )


/* ----------------------------------------------------------------
   Function sumSquares(a,b): 
        agreed inputs:  r0 = a, r1 = b
        agreed return:  r0 = return value
   ---------------------------------------------------------------- */

sumSquares:

	// When  sumSquares begin, we will have: r0 = a, r1 = b

	mul	r2, r0, r0	// r2 = a*a
	mul	r3, r1, r1	// r3 = b*b

	add	r0, r2, r3	// r0 = a*a + b*b
				// The result value is now in r0

	mov	pc, lr		// Return to the caller

CodeEnd:
    	nop

/* --------------------------------------------------
   Begin of the permanent program variables
   -------------------------------------------------- */
	.data
DataStart:

x:	.4byte	3
y:	.4byte	4
z:	.4byte	-1

DataEnd:

	.end