//
//  Illustrate problem when you use registers to store important values 
//  and call another method
//
/* --------------------------------------------------
   Define required labels for EGTAPI
   -------------------------------------------------- */
        .global main, Stop, CodeEnd, DataStart, DataEnd
	.global square 

/* --------------------------------------------------
   Begin of the program instructions
   -------------------------------------------------- */
	.text
main:
	// *********************************************  
	//  Test (1): result = square(3) 
	//  Test (2): result = square(3) + square(4)
	// *********************************************
	mov 	r0, #3
	bl	square		// r0 = 3*3

	mov	r9, r0		// Save result (r0) in reg r9 ?????


        mov     r0, #4
        bl      square          // r0 = 4*4

	add	r0, r9, r0


        movw    r1, #:lower16:result
        movt    r1, #:upper16:result
        str     r0, [r1]        // Store result



Stop:
	nop			   // Stop point of main( )
















/* ----------------------------------------------------------------
   Function square(x)
        agreed inputs:  r0 = x
        agreed return:  r0 = x*x
   ---------------------------------------------------------------- */

square:
	mov	r1, r0
	mul	r0, r1, r0

	mov	r1, #0
	mov	r2, #0
	mov	r3, #0
	mov	r4, #0
	mov	r5, #0
	mov	r6, #0
	mov	r7, #0
	mov	r8, #0
	mov	r9, #0
	mov	r10, #0

	mov	pc, lr		// Return to the caller

CodeEnd:
    	nop

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

result:	.skip 4

DataEnd:

	.end