-fomit-frame-pointer 编译选项在gcc 4.8.2版本中的汇编代码研究

#include 
 
   
    
  

void fun(void) { printf("fun"); }

int main(int argc, char *argv[]){ fun(); return 0;}



$ gcc -o test_ffp test.c                                $ gcc -fomit-frame-pointer -o test_ffp test.c

-rwxr-xr-x 1 Admin 40968 Jan 23 21:14 test.exe          -rwxr-xr-x 1 Admin 40968 Jan 23 21:22 test_ffp.exe

$ gdb -q test.exe                                       $ gdb -q test_ffp.exe 

(gdb) disass main                                       (gdb) disass main   

Dump of assembler code for \

--ction main:               Dump of assembler code for \

--ction main:

   0x00401574 <+0>:     push   %ebp                        0x00401573 <+0>:     push   %ebp

   0x00401575 <+1>:     mov    %esp,%ebp                   0x00401574 <+1>:     mov    %esp,%ebp

   0x00401577 <+3>:     and    $0xfffffff0,%esp            0x00401576 <+3>:     and    $0xfffffff0,%esp

   0x0040157a <+6>:     call   0x401fb0 <__main>           0x00401579 <+6>:     call   0x401fb0 <__main>

   0x0040157f <+11>:    call   0x401560 
  
    
      0x0040157e <+11>: call 0x401560 
     
       0x00401584 <+16>: mov $0x0,%eax 0x00401583 <+16>: mov $0x0,%eax 0x00401589 <+21>: leave 0x00401588 <+21>: leave 0x0040158a <+22>: ret 0x00401589 <+22>: ret 0x0040158b <+23>: nop 0x0040158a <+23>: nop 0x0040158c <+24>: xchg %ax,%ax 0x0040158b <+24>: nop 0x0040158e <+26>: xchg %ax,%ax 0x0040158c <+25>: xchg %ax,%ax End of assembler dump. End of assembler dump. (gdb) disass fun (gdb) disass fun Dump of assembler code for \ --ction fun: Dump of assembler code for \ --ction fun: 0x00401560 <+0>: push %ebp 0x00401560 <+0>: sub $0x1c,%esp 0x00401561 <+1>: mov %esp,%ebp 0x00401563 <+3>: movl $0x404024,(%esp) 0x00401563 <+3>: sub $0x18,%esp 0x0040156a <+10>: call 0x402738 
      
        0x00401566 <+6>: movl $0x404024,(%esp) 0x0040156f <+15>: add $0x1c,%esp 0x0040156d <+13>: call 0x402738 
       
         0x00401572 <+18>: ret 0x00401572 <+18>: leave End of assembler dump. 0x00401573 <+19>: ret (gdb) End of assembler dump. (gdb) 
        
       
      
    
 
   

文件大小是一样,结果fun函数的汇编代码中 push %ebp; leave; 没有啦.