/* ARM assembly AARCH64 Raspberry PI 3B */
/*  program Strip comments from a string   */

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

/*******************************************/
/* macros                             */
/*******************************************/
//.include "../../ficmacros64.inc"            // for developper debugging

/*********************************/
/* Initialized data              */
/*********************************/
.data
szMessDebutPgm:       .asciz "Program 64 bits start. \n"
szCarriageReturn:     .asciz "\n"
szMessFinOK:          .asciz "Program normal end. \n"

szString1:            .asciz "apples, pears # and bananas"
szString2:            .asciz "apples, pears ; and bananas"
.align 4
/*********************************/
/* UnInitialized data            */
/*********************************/
.bss
.align 4

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

    ldr x0,qAdrszString1
    mov x1,#'#'
    bl suppComment
    ldr x0,qAdrszString1
    bl affichageMess
    ldr x0,qAdrszCarriageReturn
    bl affichageMess

    ldr x0,qAdrszString2
    mov x1,#';'
    bl suppComment
    ldr x0,qAdrszString1
    bl affichageMess
    ldr x0,qAdrszCarriageReturn
    bl affichageMess

    ldr x0,qAdrszMessFinOK
    bl affichageMess

100:
   mov x8,EXIT
    svc #0                      // system call
qAdrszMessDebutPgm:          .quad szMessDebutPgm
qAdrszMessFinOK:             .quad szMessFinOK
qAdrszCarriageReturn:        .quad szCarriageReturn
qAdrszString1:               .quad szString1
qAdrszString2:               .quad szString2

/******************************************************************/
/*            strip comment string                                        */
/******************************************************************/
/* x0 contains string address  */
/* x1 contains comment markers */
/* x0 returns length of string */
suppComment:
    stp x1,lr,[sp,-16]!
    stp x2,x3,[sp,-16]!
    mov x2,#0              // indice string
1:
    ldrb w3,[x0,x2]
    cmp x3,#0             // end string
    csel x0,x2,x0,eq
    beq 100f
    cmp x3,x1
    cinc x2,x2,ne
    bne 1b
    mov x3,#0
    strb w3,[x0,x2]
    mov x0,x2
100:
    ldp x2,x3,[sp],16
    ldp x1,lr,[sp],16
    ret

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