179 lines
6.9 KiB
Plaintext
179 lines
6.9 KiB
Plaintext
/* ARM assembly Raspberry PI */
|
|
/* program quickSelection.s */
|
|
/* look pseudo code in wikipedia quickselect */
|
|
|
|
/************************************/
|
|
/* Constantes */
|
|
/************************************/
|
|
/* for constantes see task include a file in arm assembly */
|
|
.include "../constantes.inc"
|
|
|
|
/*********************************/
|
|
/* Initialized data */
|
|
/*********************************/
|
|
.data
|
|
szMessResultIndex: .asciz "index : "
|
|
szMessResultValue: .asciz " value : "
|
|
szCarriageReturn: .asciz "\n"
|
|
|
|
.align 4
|
|
TableNumber: .int 9, 8, 7, 6, 5, 0, 1, 2, 3, 4
|
|
.equ NBELEMENTS, (. - TableNumber) / 4
|
|
/*********************************/
|
|
/* UnInitialized data */
|
|
/*********************************/
|
|
.bss
|
|
sZoneConv: .skip 24
|
|
sZoneConv1: .skip 24
|
|
/*********************************/
|
|
/* code section */
|
|
/*********************************/
|
|
.text
|
|
.global main
|
|
main: @ entry of program
|
|
mov r5,#0
|
|
1:
|
|
ldr r0,iAdrTableNumber @ address number table
|
|
mov r1,#0 @ index first item
|
|
mov r2,#NBELEMENTS -1 @ index last item
|
|
mov r3,r5 @ search index
|
|
bl select @ call selection
|
|
ldr r1,iAdrsZoneConv
|
|
bl conversion10 @ convert result to decimal
|
|
mov r0,r5
|
|
ldr r1,iAdrsZoneConv1
|
|
bl conversion10 @ convert index to decimal
|
|
mov r0,#5 @ and display result
|
|
ldr r1,iAdrszMessResultIndex
|
|
ldr r2,iAdrsZoneConv1
|
|
ldr r3,iAdrszMessResultValue
|
|
ldr r4,iAdrsZoneConv
|
|
push {r4}
|
|
ldr r4,iAdrszCarriageReturn
|
|
push {r4}
|
|
bl displayStrings
|
|
add sp,sp,#8 @ stack alignement (2 push)
|
|
add r5,r5,#1
|
|
cmp r5,#NBELEMENTS
|
|
blt 1b
|
|
|
|
100: @ standard end of the program
|
|
mov r0, #0 @ return code
|
|
mov r7, #EXIT @ request to exit program
|
|
svc #0 @ perform the system call
|
|
|
|
iAdrszCarriageReturn: .int szCarriageReturn
|
|
iAdrTableNumber: .int TableNumber
|
|
iAdrsZoneConv: .int sZoneConv
|
|
iAdrsZoneConv1: .int sZoneConv1
|
|
iAdrszMessResultIndex: .int szMessResultIndex
|
|
iAdrszMessResultValue: .int szMessResultValue
|
|
|
|
/***************************************************/
|
|
/* Appel récursif selection */
|
|
/***************************************************/
|
|
/* r0 contains the address of table */
|
|
/* r1 contains index of first item */
|
|
/* r2 contains index of last item */
|
|
/* r3 contains search index */
|
|
select:
|
|
push {r1-r6,lr} @ save registers
|
|
mov r6,r3 @ save search index
|
|
cmp r1,r2 @ first = last ?
|
|
ldreq r0,[r0,r1,lsl #2] @ return value of first index
|
|
beq 100f @ yes -> end
|
|
add r3,r1,r2
|
|
lsr r3,r3,#1 @ compute median pivot
|
|
mov r4,r0 @ save r0
|
|
mov r5,r2 @ save r2
|
|
bl partition @ cutting into 2 parts
|
|
cmp r6,r0 @ pivot is ok ?
|
|
ldreq r0,[r4,r0,lsl #2] @ return value
|
|
beq 100f
|
|
bgt 1f
|
|
sub r2,r0,#1 @ index partition - 1
|
|
mov r0,r4 @ array address
|
|
mov r3,r6 @ search index
|
|
bl select @ select lower part
|
|
b 100f
|
|
1:
|
|
add r1,r0,#1 @ index begin = index partition + 1
|
|
mov r0,r4 @ array address
|
|
mov r2,r5 @ last item
|
|
mov r3,r6 @ search index
|
|
bl select @ select higter part
|
|
100: @ end function
|
|
pop {r1-r6,pc} @ restaur register
|
|
/******************************************************************/
|
|
/* Partition table elements */
|
|
/******************************************************************/
|
|
/* r0 contains the address of table */
|
|
/* r1 contains index of first item */
|
|
/* r2 contains index of last item */
|
|
/* r3 contains index of pivot */
|
|
partition:
|
|
push {r1-r6,lr} @ save registers
|
|
ldr r4,[r0,r3,lsl #2] @ load value of pivot
|
|
ldr r5,[r0,r2,lsl #2] @ load value last index
|
|
str r5,[r0,r3,lsl #2] @ swap value of pivot
|
|
str r4,[r0,r2,lsl #2] @ and value last index
|
|
mov r3,r1 @ init with first index
|
|
1: @ begin loop
|
|
ldr r6,[r0,r3,lsl #2] @ load value
|
|
cmp r6,r4 @ compare loop value and pivot value
|
|
ldrlt r5,[r0,r1,lsl #2] @ if < swap value table
|
|
strlt r6,[r0,r1,lsl #2]
|
|
strlt r5,[r0,r3,lsl #2]
|
|
addlt r1,#1 @ and increment index 1
|
|
add r3,#1 @ increment index 2
|
|
cmp r3,r2 @ end ?
|
|
blt 1b @ no loop
|
|
ldr r5,[r0,r1,lsl #2] @ swap value
|
|
str r4,[r0,r1,lsl #2]
|
|
str r5,[r0,r2,lsl #2]
|
|
mov r0,r1 @ return index partition
|
|
100:
|
|
pop {r1-r6,pc}
|
|
|
|
/***************************************************/
|
|
/* display multi strings */
|
|
/***************************************************/
|
|
/* r0 contains number strings address */
|
|
/* r1 address string1 */
|
|
/* r2 address string2 */
|
|
/* r3 address string3 */
|
|
/* other address on the stack */
|
|
/* thinck to add number other address * 4 to add to the stack */
|
|
displayStrings: @ INFO: displayStrings
|
|
push {r1-r4,fp,lr} @ save des registres
|
|
add fp,sp,#24 @ save paraméters address (6 registers saved * 4 bytes)
|
|
mov r4,r0 @ save strings number
|
|
cmp r4,#0 @ 0 string -> end
|
|
ble 100f
|
|
mov r0,r1 @ string 1
|
|
bl affichageMess
|
|
cmp r4,#1 @ number > 1
|
|
ble 100f
|
|
mov r0,r2
|
|
bl affichageMess
|
|
cmp r4,#2
|
|
ble 100f
|
|
mov r0,r3
|
|
bl affichageMess
|
|
cmp r4,#3
|
|
ble 100f
|
|
mov r3,#3
|
|
sub r2,r4,#4
|
|
1: @ loop extract address string on stack
|
|
ldr r0,[fp,r2,lsl #2]
|
|
bl affichageMess
|
|
subs r2,#1
|
|
bge 1b
|
|
100:
|
|
pop {r1-r4,fp,pc}
|
|
/***************************************************/
|
|
/* ROUTINES INCLUDE */
|
|
/***************************************************/
|
|
/* for this file see task include a file in language ARM assembly*/
|
|
.include "../affichage.inc"
|