Hello, All:
There is a simple program printf.c
#include <stdio.h>
int main()
{
printf("%d\n",5);
printf("%f\n",4.0);
return 1;
}
When I compile it using "gcc -S printf.c", I get as follows.
1 .file "print.c"
2 .section .rodata
3 .LC0:
4 .string "%d\n"
5 .LC1:
6 .string "%f\n"
7 .text
8 .globl main
9 .type main,@function
10 main:
11 pushl %ebp
12 movl %esp, %ebp
13 subl $8, %esp
14 andl $-16, %esp
15 movl $0, %eax
16 subl %eax, %esp
17 subl $8, %esp
18 pushl $5
19 pushl $.LC0
20 call printf
21 addl $16, %esp
22 subl $4, %esp
23 pushl $1074790400
24 pushl $0
25 pushl $.LC1
26 call printf
27 addl $16, %esp
28 movl $1, %eax
29 leave
30 ret
31 .Lfe1:
32 .size main,.Lfe1-main
33 .ident "GCC: (GNU) 3.2.2 20030222 (Red Hat Linux 3.2.2-5)"
The colored lines show that gcc has aligned the stack to 16-bytes. Why is that?
Regards,
Kevin
>From Southeast University, China
