Order two numerical lists: Difference between revisions

=={{header|ARM Assembly}}==

{{works with|as|Raspberry Pi}}

<lang ARM Assembly>

/* ARM assembly Raspberry PI */

/* program orderlist.s */

/* Constantes */

.equ STDOUT, 1 @ Linux output console

.equ EXIT, 1 @ Linux syscall

.equ WRITE, 4 @ Linux syscall

/*********************************/

/* Initialized data */

/*********************************/

.data

szMessResult1: .asciz "List1 < List2 \n" @ message result

szMessResult2: .asciz "List1 => List2 \n" @ message result

szCarriageReturn: .asciz "\n"

iTabList1: .int 1,2,3,4,5

.equ NBELEMENTS1, (. - iTabList1) /4

iTabList2: .int 1,2,1,5,2,2

.equ NBELEMENTS2, (. - iTabList2) /4

iTabList3: .int 1,2,3,4,5

.equ NBELEMENTS3, (. - iTabList3) /4

iTabList4: .int 1,2,3,4,5,6

.equ NBELEMENTS4, (. - iTabList4) /4

/*********************************/

/* UnInitialized data */

/*********************************/

.bss

/*********************************/

/* code section */

/*********************************/

.text

.global main

main: @ entry of program

ldr r0,iAdriTabList1

mov r1,#NBELEMENTS1

ldr r2,iAdriTabList2

mov r3,#NBELEMENTS2

bl listeOrder

cmp r0,#0 @ false ?

beq 1f @ yes

ldr r0,iAdrszMessResult1 @ list 1 < list 2

bl affichageMess @ display message

b 2f

1:

ldr r0,iAdrszMessResult2

bl affichageMess @ display message

2:

ldr r0,iAdriTabList1

mov r1,#NBELEMENTS1

ldr r2,iAdriTabList3

mov r3,#NBELEMENTS3

bl listeOrder

cmp r0,#0 @ false ?

beq 3f @ yes

ldr r0,iAdrszMessResult1 @ list 1 < list 2

bl affichageMess @ display message

b 4f

3:

ldr r0,iAdrszMessResult2

bl affichageMess @ display message

4:

ldr r0,iAdriTabList1

mov r1,#NBELEMENTS1

ldr r2,iAdriTabList4

mov r3,#NBELEMENTS4

bl listeOrder

cmp r0,#0 @ false ?

beq 5f @ yes

ldr r0,iAdrszMessResult1 @ list 1 < list 2

bl affichageMess @ display message

b 6f

5:

ldr r0,iAdrszMessResult2

bl affichageMess @ display message

6:

100: @ standard end of the program

mov r0, #0 @ return code

mov r7, #EXIT @ request to exit program

svc #0 @ perform the system call

iAdriTabList1: .int iTabList1

iAdriTabList2: .int iTabList2

iAdriTabList3: .int iTabList3

iAdriTabList4: .int iTabList4

iAdrszMessResult1: .int szMessResult1

iAdrszMessResult2: .int szMessResult2

iAdrszCarriageReturn: .int szCarriageReturn

/******************************************************************/

/* display text with size calculation */

/******************************************************************/

/* r0 contains the address of list 1 */

/* r1 contains list 1 size */

/* r2 contains the address of list 2 */

/* r3 contains list 2 size */

/* r0 returns 1 if list1 < list2 */

/* r0 returns 0 else */

listeOrder:

push {r1-r7,lr} @ save registres

cmp r1,#0 @ list 1 size = zero ?

moveq r0,#-1 @ yes -> error

beq 100f

cmp r3,#0 @ list 2 size = zero ?

moveq r0,#-2 @ yes -> error

beq 100f

mov r4,#0 @ index list 1

mov r5,#0 @ index list 2

1:

ldr r6,[r0,r4,lsl #2] @ load list 1 element

ldr r7,[r2,r5,lsl #2] @ load list 2 element

cmp r6,r7 @ compar

movgt r0,#0 @ list 1 > list 2 ?

bgt 100f

beq 2f @ list 1 = list 2

add r4,#1 @ increment index 1

cmp r4,r1 @ end list ?

movge r0,#1 @ yes -> ok list 1 < list 2

bge 100f

b 1b @ else loop

2:

add r4,#1 @ increment index 1

cmp r4,r1 @ end list ?

bge 3f @ yes -> verif size

add r5,#1 @ else increment index 2

cmp r5,r3 @ end list 2 ?

movge r0,#0 @ yes -> list 2 < list 1

bge 100f

b 1b @ else loop

3:

cmp r1,r3 @ compar size

movge r0,#0 @ list 2 < list 1

movlt r0,#1 @ list 1 < list 2

100:

pop {r1-r7,lr} @ restaur registers

bx lr @ return

/******************************************************************/

/* display text with size calculation */

/******************************************************************/

/* r0 contains the address of the message */

affichageMess:

push {r0,r1,r2,r7,lr} @ save registres

mov r2,#0 @ counter length

1: @ loop length calculation

ldrb r1,[r0,r2] @ read octet start position + index

cmp r1,#0 @ if 0 its over

addne r2,r2,#1 @ else add 1 in the length

bne 1b @ and loop

@ so here r2 contains the length of the message

mov r1,r0 @ address message in r1

mov r0,#STDOUT @ code to write to the standard output Linux

mov r7, #WRITE @ code call system "write"

svc #0 @ call systeme

pop {r0,r1,r2,r7,lr} @ restaur registers */

bx lr @ return

</lang>