00. 目录
01. if 结构一
.section .rodata
.align 2
.LC0:
.string "i > 10\n"
.LC1:
.string "i <= 10\n"
.section .text
.align 2
.global main
main:
push {lr}
mov r2, #1
cmp r2, #10
ldrgt r0, =.LC0
ldrle r0, =.LC1
bl printf
mov r0, #0
pop {pc}
02. if 结构二
.section .rodata
.align 2
.LC0:
.string "i > 10\n"
.LC1:
.string "i <= 10\n"
.section .text
.align 2
.global main
main:
push {lr}
mov r2, #1
cmp r2, #10
bgt do1
b do2
do1:
ldr r0, =.LC0
bl printf
b out
do2:
ldr r0, =.LC1
bl printf
out:
mov r0, #0
pop {pc}
03. if 结构三
.section .rodata
.align 2
.LC0:
.string "i > 10\n"
.LC1:
.string "i < 10\n"
.LC2:
.string "i == 10\n"
.section .text
.align 2
.global main
main:
push {lr}
mov r2, #1
cmp r2, #10
bgt do1
blt do2
b do3
do1:
ldr r0, =.LC0
bl printf
b out
do2:
ldr r0, =.LC1
bl printf
b out
do3:
ldr r0, =.LC2
bl printf
out:
mov r0, #0
pop {pc}
04. if 结构四
if(i > 10)
...
else if(i + j > 10)
...
else if(j < 10)
...
.section .rodata
.align 2
.LC0:
.string "i > 10\n"
.LC1:
.string "i + j > 10\n"
.LC2:
.string "j < 10\n"
.section .text
.align 2
.global main
main:
push {lr}
mov r2, #100
mov r3, #2
cmp r2, #10
bgt do1
add r1, r2, r3
cmp r1, #10
bgt do2
cmp r3, #10
blt do3
b out
do1:
ldr r0, =.LC0
bl printf
b out
do2:
ldr r0, =.LC1
bl printf
b out
do3:
ldr r0, =.LC2
bl printf
out:
mov r0, #0
pop {pc}
05. if 结构五
.section .rodata
.align 2
.LC0:
.string "i > 10 && i < 20\n"
.section .text
.align 2
.global main
main:
push {lr}
mov r2, #15
cmp r2, #10
ble out
cmp r2, #20
blt do1
b out
do1:
ldr r0, =.LC0
bl printf
out:
mov r0, #0
pop {pc}
06. switch结构
C语言代码
#include <stdio.h>
int main(void)
{
int i = 10;
char ch = 'a';
switch(i)
{
case 1:
printf("val = %d \n", i);
break;
case 345:
printf("val = %d \n", i);
break;
case 23:
printf("val = %d \n", i);
break;
case 7:
printf("val = %d \n", i);
break;
case 1234:
printf("val = %d \n", i);
break;
case 17:
printf("val = %d \n", i);
break;
case 10:
printf("val = %d \n", i);
break;
}
return 0;
}
汇编语言代码
.section .rodata
.align 2
.LC0:
.ascii "val = %d \012\000"
.text
.align 2
.global main
main:
stmfd sp!, {fp, lr}
add fp, sp, #4
sub sp, sp, #8
mov r3, #10
str r3, [fp, #-8]
mov r3, #97
strb r3, [fp, #-9]
ldr r3, [fp, #-8]
cmp r3, #17
beq .L6
cmp r3, #17
bgt .L10
cmp r3, #7
beq .L4
cmp r3, #10
beq .L5
cmp r3, #1
beq .L3
b .L2
.L10:
ldr r2, .L11
cmp r3, r2
beq .L8
ldr r2, .L11+4
cmp r3, r2
beq .L9
cmp r3, #23
beq .L7
b .L2
.L3:
ldr r3, .L11+8
mov r0, r3
ldr r1, [fp, #-8]
bl printf
b .L2
.L8:
ldr r3, .L11+8
mov r0, r3
ldr r1, [fp, #-8]
bl printf
b .L2
.L7:
ldr r3, .L11+8
mov r0, r3
ldr r1, [fp, #-8]
bl printf
b .L2
.L4:
ldr r3, .L11+8
mov r0, r3
ldr r1, [fp, #-8]
bl printf
b .L2
.L9:
ldr r3, .L11+8
mov r0, r3
ldr r1, [fp, #-8]
bl printf
b .L2
.L6:
ldr r3, .L11+8
mov r0, r3
ldr r1, [fp, #-8]
bl printf
b .L2
.L5:
ldr r3, .L11+8
mov r0, r3
ldr r1, [fp, #-8]
bl printf
mov r0, r0 @ nop
.L2:
mov r3, #0
mov r0, r3
sub sp, fp, #4
ldmfd sp!, {fp, pc}
.L12:
.align 2
.L11:
.word 345
.word 1234
.word .LC0
.size main, .-main
.ident "GCC: (ctng-1.8.1-FA) 4.5.1"
.section .note.GNU-stack,"",%progbits