小编Los*_*min的帖子

我在文件中有一个C程序delay.c:

void delay(int num)
{
   volatile int i;
   for(i=0; i<num; i++);
}

然后我使用命令在ARM模拟器(更具体地说)上用gcc 4.6.3编译程序gcc -g -O1 -o delay.o delay.c.组装delay.o是:

00000000 <delay>:
   0:   e24dd008    sub sp, sp, #8
   4:   e3a03000    mov r3, #0
   8:   e58d3004    str r3, [sp, #4]
   c:   e59d3004    ldr r3, [sp, #4]
  10:   e1500003    cmp r0, r3
  14:   da000005    ble 30 <delay+0x30>
  18:   e59d3004    ldr r3, [sp, #4]
  1c:   e2833001    add r3, r3, #1
  20:   e58d3004    str r3, [sp, #4]
  24:   e59d3004 …