/* ARM assembly AARCH64 Raspberry PI 3B */
/*  program numfibo64.s   */

/*******************************************/
/* Constantes                              */
/*******************************************/
/* for this file see task include a file in language AArch64 assembly*/
.include "../includeConstantesARM64.inc"

/*********************************/
/* Initialized data              */
/*********************************/
.data
szMessDebutPgm:    .asciz "Program 64 bits start. \n"
szCarriageReturn:  .asciz "\n"
szMessFinOK:       .asciz "Program normal end. \n"
szMessErreur:      .asciz "Error  !!!\n"
szMessFibo:        .asciz "\nFibonaci numbers :\n"

.align 4
/*********************************/
/* UnInitialized data            */
/*********************************/
.bss
sZoneConv:               .skip 24
.align 4

/*********************************/
/*  code section                 */
/*********************************/
.text
.global main
main:
    ldr x0,qAdrszMessDebutPgm
    bl affichageMess            // start message

    ldr x0,qAdrszMessFibo
    bl affichageMess
    mov x0,#0                   // rank
    mov x1,#0                   // L(0)  or L(n-2)
    mov x2,#1                   // L(1)  or L(n-1)
    mov x3,#20                  // maxi
    bl genererFibo

    ldr x0,qAdrszMessFinOK
    bl affichageMess
    b 100f
99:
    ldr x0,qAdrszMessErreur        // error
    bl affichageMess
    mov x0, #1                     // return code error
    b 100f
100:
    mov x8,EXIT
    svc #0                         // system call
qAdrszMessDebutPgm:          .quad szMessDebutPgm
qAdrszMessFinOK:             .quad szMessFinOK
qAdrszMessErreur:            .quad szMessErreur
qAdrsZoneConv:               .quad sZoneConv
qAdrszMessFibo:              .quad szMessFibo
/***************************************************/
/*   Generation Fibonacci number                 */
/***************************************************/
/* x0 contains n     */
/* x1 contains L(0)  */
/* x2 contains L(1)  */
/* x3 contains limit number */
genererFibo:
    stp x4,lr,[sp,-16]!
    stp x5,x6,[sp,-16]!
    mov x4,x0
    cmp x3,#0                    // end compute ?
    ble 100f
    cmp x0,#0                    // L(0) ?
    bne 1f
    mov x0,x1
    bl displayNumber
    add x0,x4,#1                // increment rank
    sub x3,x3,#1                // decrement counter
    bl genererFibo
    b 100f
1:
    cmp x0,#1                   // L(1) ?
    bne 2f
    mov x0,x2
    bl displayNumber
    add x0,x4,#1
    sub x3,x3,#1
    bl genererFibo
    b 100f
2:
    add x5,x2,x1                // add L(n-2) L(n-1)
    mov x0,x5
    bl displayNumber
    add x0,x4,#1
    sub x3,x3,#1
    mov x1,x2                   // L(n-1) -> L(n-2)
    mov x2,x5                   // number -> L(n-1)
    bl genererFibo
    b 100f

100:
    ldp x5,x6,[sp],16
    ldp x4,lr,[sp],16         // TODO: a completer
    ret
/***************************************************/
/*   display number                  */
/***************************************************/
/* x0 contains number  */
displayNumber:
    stp x1,lr,[sp,-16]!       // TODO: a completer
    ldr x1,qAdrsZoneConv
    bl conversion10
    ldr x0,qAdrsZoneConv
    bl affichageMess
    ldr x0,qAdrszCarriageReturn
    bl affichageMess
100:
    ldp x1,lr,[sp],16         // TODO: a completer
    ret
qAdrszCarriageReturn:         .quad szCarriageReturn


/***************************************************/
/*      ROUTINES INCLUDE                 */
/***************************************************/
/* for this file see task include a file in language AArch64 assembly*/
.include "../includeARM64.inc"