今天总算看明白了网上一段mips汇编代码,感觉很爽阿,呵呵,只是让大虾见笑了。原文章(包含该代码)在如下网址:http://www.xtrj.org/mips/, 题目是MIPS体系结构剖析,编程与实践(作者:张福新,陈怀临, 2002)
C代码如下:
~/ vi Hello.c
"Hello.c" [New file]
int addFunc(int,int);
int subFunc(int);
void main()
{
int x,y,z;
x= 1;
y=2;
z = addFunc(x,y);
}
int addFunc(int x,int y)
{
int value1 = 5;
int value2;
value2 = subFunc(value1);
return (x+y+value2);
}
int subFunc(int value)
{
return value--;
}
反汇编代码后的代码:
0000000000000000
:
0: 27bdfff8 addiu $sp,$sp,-8
4: afbf0000 sw $ra,0($sp)
8: 0c000000 jal 0
c: 00000000 nop
10: 24040001 li $a0,1
14: 0c00000a jal 28
18: 24050002 li $a1,2
1c: 8fbf0000 lw $ra,0($sp)
20: 03e00008 jr $ra
24: 27bd0008 addiu $sp,$sp,8
0000000000000028 :
28: 27bdfff0 addiu $sp,$sp,-16
2c: afbf0008 sw $ra,8($sp)
30: afb10004 sw $s1,4($sp)
34: afb00000 sw $s0,0($sp)
38: 0080802d move $s0,$a0
3c: 00a0882d move $s1,$a1
40: 0c000019 jal 64
44: 24040005 li $a0,5
48: 02118021 addu $s0,$s0,$s1
4c: 02021021 addu $v0,$s0,$v0
50: 8fbf0008 lw $ra,8($sp)
54: 8fb10004 lw $s1,4($sp)
58: 8fb00000 lw $s0,0($sp)
5c: 03e00008 jr $ra
60: 27bd0010 addiu $sp,$sp,16
0000000000000064 :
64: 03e00008 jr $ra
/* Taking advantage of the mips delay slot, filling the
* result reg v0 by simply assigning the v0 as the value
*of a0. This is a bug from my c source
* codes--"value--". I should write my codes
* like "--value", instead.
68: 0080102d move $v0,$a0
为便于察看,我已经将指令全部高亮为蓝色。如果对MIPS指令不熟,看起来还是比较废劲的哦。我是对着指令解释,并画图,废了九牛二虎之力阿。搞懂后,有种毛塞顿开,总算打开门之感,颇为爽!.^_^偶正致力于往底层驱动发展,此番进步亦算是鼓励了。忘高手或者有心往此方面发展的朋友,多多交流哦。