00. 目录
文章目录
01. 循环结构-死循环
第一种方式：死循环
.section .rodata
.align 2
.LC0:
.string "val = %p\n"
.section .text
.align 2
.global main
main:
push {lr}
loop:
b loop
mov r0, #0
pop {pc}
第二种方式：死循环
.section .rodata
.align 2
.LC0:
.string "val = %p\n"
.section .text
.align 2
.global main
main:
push {lr}
b .
mov r0, #0
pop {pc}
第三种方式：死循环
.section .rodata
.align 2
.LC0:
.string "val = %p\n"
.section .text
.align 2
.global main
main:
push {lr}
sub pc, pc, #8
mov r0, #0
pop {pc}
02. 循环结构-累加和
输出1 + 2 + 3 + … + 10的和:
.section .rodata
.align 2
.LC0:
.string "val = %d\n"
.section .text
.align 2
.global main
main:
push {lr}
mov r1, #0
loop:
add r1, r1, #1
cmp r1, #10
blt loop
ldr r0, =.LC0
bl printf
mov r0, #0
pop {pc}
03. 循环结构-循环输出
方式一：输出1到10之间的数据
.section .rodata
.align 2
.LC0:
.string "val = %d\n"
.section .text
.align 2
.global main
main:
push {lr}
mov r4, #1
loop:
ldr r0, =.LC0
mov r1, r4
bl printf
add r4, r4, #1
cmp r4, #10
ble loop
mov r0, #0
pop {pc}
方式二：输出1到10之间的数据
.section .rodata
.align 2
.LC0:
.string "val = %d\n"
.section .text
.align 2
.global main
main:
push {lr}
mov r1, #1
loop:
ldr r0, =.LC0
push {r1}
bl printf
pop {r1}
add r1, r1, #1
cmp r1, #10
ble loop
mov r0, #0
pop {pc}
04. 循环结构-循环输出
方式一：输出1到100之内的所有奇数
.section .rodata
.align 2
.LC0:
.string "val = %d\n"
.section .text
.align 2
.global main
main:
push {lr}
mov r4, #1
loop:
mov r1, r4
ldr r0, =.LC0
bl printf
add r4, r4, #2
cmp r4, #100
ble loop
mov r0, #0
pop {pc}
方式二：输出1到100之内的所有奇数
.section .rodata
.align 2
.LC0:
.string "val = %d\n"
.section .text
.align 2
.global main
main:
push {lr}
mov r4, #1
loop:
mov r1, r4
ldr r0, =.LC0
ands r2, r4, #1
cmp r2, #0
blne printf
add r4, r4, #2
cmp r4, #100
ble loop
mov r0, #0
pop {pc}
方式三：输出1到100之内的所有奇数
.section .rodata
.align 2
.LC0:
.string "val = %d\n"
.section .text
.align 2
.global main
main:
push {lr}
mov r4, #1
loop:
mov r1, r4
ldr r0, =.LC0
@ands r2, r4, #1
@cmp r2, #0
tst r4, #1
blne printf
add r4, r4, #2
@cmp r4, #100
subs r1, r4, #100
ble loop
mov r0, #0
pop {pc}
05. 随机数
产生100个随机数,输出其中的奇数
.section .rodata
.align 2
.LC0:
.string "val = %d\n"
.section .text
.align 2
.global main
main:
push {lr}
bl getpid
bl srandom
mov r4, #1
loop:
bl random
mov r1, r0
tst r1, #1
ldr r0, =.LC0
blne printf
add r4, r4, #1
cmp r4, #100
ble loop
mov r0, #0
pop {pc}
产生100个0-255间的随机数,输出其中的奇数
.section .rodata
.align 2
.LC0:
.string "val = %d\n"
.section .text
.align 2
.global main
main:
push {lr}
bl getpid
bl srandom
mov r4, #1
loop:
bl random
mov r1, r0
and r1, #0xff
tst r1, #1
ldr r0, =.LC0
blne printf
add r4, r4, #1
cmp r4, #100
ble loop
mov r0, #0
pop {pc}
06. 综合应用一
输出九九乘法表
.section .rodata
.align 2
.LC0:
.string "%2d*%2d=%2d "
.LC1:
.string "\n"
.section .text
.align 2
.global main
main:
push {lr}
mov r4, #1
loop:
mov r5, #1
loop2:
ldr r0, =.LC0
mov r1, r5
mov r2, r4
mul r3, r4, r5
bl printf
add r5, r5, #1
cmp r5, r4
ble loop2
ldr r0, =.LC1
bl printf
add r4, r4, #1
cmp r4, #9
ble loop
mov r0, #0
pop {pc}
07. 综合应用二
输出棱形
.section .rodata
.align 2
.LC0:
.string " "
.LC1:
.string "*"
.LC2:
.string "\n"
.section .text
.align 2
.global main
main:
push {lr}
mov r4, #0
loop:
cmp r4, #10
bge out1
mov r5, #0
loop1:
rsb r6, r4, #9
cmp r5, r6
bge out2
ldr r0, =.LC0
bl printf
add r5, r5, #1
cmp r5, r6
blt loop1
out2:
mov r5, #0
loop2:
mov r7, #2
mul r6, r4, r7
add r6, r6, #1
cmp r5, r6
bgt out3
ldr r0, =.LC1
bl printf
add r5, r5, #1
cmp r5, r6
blt loop2
out3:
ldr r0, =.LC2
bl printf
add r4, r4, #1
cmp r4, #10
blt loop
out1:
@for (i = 0; i < 9; i++)
mov r4, #0
loop3:
cmp r4, #9
bge out4
mov r5, #0
loop4:
cmp r5, r4
bgt out5
ldr r0, =.LC0
bl printf
add r5, r5, #1
cmp r5, r5
ble loop4
out5:
mov r5, #0
loop5:
rsb r7, r4, #9
mov r8, #2
mul r6, r7, r8
sub r6, r6, #1
cmp r5, r6
bge out6
ldr r0, =.LC1
bl printf
add r5, r5, #1
cmp r5, r6
blt loop5
out6:
ldr r0, =.LC2
bl printf
add r4, r4, #1
cmp r4, #9
blt loop3
out4:
mov r0, #0
pop {pc}
执行结果
[root@itcast 2nd]# ./a.out
*
***
*****
*******
*********
***********
*************
***************
*****************
*******************
*****************
***************
*************
***********
*********
*******
*****
***
*
[root@itcast 2nd]#
08. 综合应用三
输出棱形
.section .rodata
.align 2
.LC0:
.string " "
.LC1:
.string "*"
.LC2:
.string "\n"
.section .text
.align 2
.global main
main:
push {lr}
mov r4, #0
2:
cmp r4, #10
bge 2f
mov r5, #0
1:
rsb r6, r4, #9
cmp r5, r6
bge 1f
ldr r0, =.LC0
bl printf
add r5, r5, #1
cmp r5, r6
blt 1b
1:
mov r5, #0
1:
mov r7, #2
mul r6, r4, r7
add r6, r6, #1
cmp r5, r6
bgt 1f
ldr r0, =.LC1
bl printf
add r5, r5, #1
cmp r5, r6
blt 1b
1:
ldr r0, =.LC2
bl printf
add r4, r4, #1
cmp r4, #10
blt 2b
2:
@for (i = 0; i < 9; i++)
mov r4, #0
2:
cmp r4, #9
bge 2f
mov r5, #0
1:
cmp r5, r4
bgt 1f
ldr r0, =.LC0
bl printf
add r5, r5, #1
cmp r5, r5
ble 1b
1:
mov r5, #0
1:
rsb r7, r4, #9
mov r8, #2
mul r6, r7, r8
sub r6, r6, #1
cmp r5, r6
bge 1f
ldr r0, =.LC1
bl printf
add r5, r5, #1
cmp r5, r6
blt 1b
1:
ldr r0, =.LC2
bl printf
add r4, r4, #1
cmp r4, #9
blt 2b
2:
mov r0, #0
pop {pc}
执行结果
[root@itcast 2nd]# ./a.out
*
***
*****
*******
*********
***********
*************
***************
*****************
*******************
*****************
***************
*************
***********
*********
*******
*****
***
*
[root@itcast 2nd]#