在Unix 和 Linux 系统中,汇编语言格式采用的较多的是 AT&T 格式。
C程序:
int g(int x)
{
return x + 27;
}
int f(int x)
{
return g(x);
}
int main(void)
{
return f(2016) + 2;
}
.file "main.c"
.text
.globl g
.type g, @function
g:
.LFB0:
.cfi_startproc
pushq %rbp
.cfi_def_cfa_offset 16
.cfi_offset 6, -16
movq %rsp, %rbp
.cfi_def_cfa_register 6
movl %edi, -4(%rbp)
movl -4(%rbp), %eax
addl $27, %eax
popq %rbp
.cfi_def_cfa 7, 8
ret
.cfi_endproc
.LFE0:
.size g, .-g
.globl f
.type f, @function
f:
.LFB1:
.cfi_startproc
pushq %rbp
.cfi_def_cfa_offset 16
.cfi_offset 6, -16
movq %rsp, %rbp
.cfi_def_cfa_register 6
subq $8, %rsp
movl %edi, -4(%rbp)
movl -4(%rbp), %eax
movl %eax, %edi
call g
leave
.cfi_def_cfa 7, 8
ret
.cfi_endproc
.LFE1:
.size f, .-f
.globl main
.type main, @function
main:
.LFB2:
.cfi_startproc
pushq %rbp
.cfi_def_cfa_offset 16
.cfi_offset 6, -16
movq %rsp, %rbp
.cfi_def_cfa_register 6
movl $2016, %edi
call f
addl $2, %eax
popq %rbp
.cfi_def_cfa 7, 8
ret
.cfi_endproc
.LFE2:
.size main, .-main
.ident "GCC: (Ubuntu 4.8.4-2ubuntu1~14.04) 4.8.4"
.section .note.GNU-stack,"",@progbits
去掉用于链接和版本信息后的计算机会执行的汇编代码:
g:
pushq %rbp
movq %rsp, %rbp
movl %edi, -4(%rbp)
movl -4(%rbp), %eax
addl $27, %eax
popq %rbp
ret
f:
pushq %rbp
movq %rsp, %rbp
subq $8, %rsp
movl %edi, -4(%rbp)
movl -4(%rbp), %eax
movl %eax, %edi
call g
leave
ret
main:
pushq %rbp
movq %rsp, %rbp
movl $2016, %edi
call f
addl $2, %eax
popq %rbp
ret
实验截图:
作者:冯峰
原创作品转载请注明出处
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