#include <stdio.h>
int func2(int a){
int ret;
ret = a + 1;
return ret;
}
int func1(int a){
int ret;
ret = a + 1;
return func2(ret);
}
int main(){
int a = 1;
int ret;
ret = func1(a);
}
func2:
pushq %rbp
movq %rsp, %rbp
movl %edi, -20(%rbp)
movl -20(%rbp), %eax
addl $1, %eax
movl %eax, -4(%rbp)
movl -4(%rbp), %eax
popq %rbp
ret
func1:
pushq %rbp
movq %rsp, %rbp
subq $24, %rsp
movl %edi, -20(%rbp)
movl -20(%rbp), %eax
addl $1, %eax
movl %eax, -4(%rbp)
movl -4(%rbp), %eax
movl %eax, %edi
call func2
leave
ret
main:
pushq %rbp
movq %rsp, %rbp
subq $16, %rsp
movl $1, -4(%rbp)
movl -4(%rbp), %eax
movl %eax, %edi
call func1
movl %eax, -8(%rbp)
movl $0, %eax
leave
ret
leave 指令等价于:
movl %rbp, %rsp
popl rbp
#include <stdio.h>
void func2(int *a){
*a = 3;
}
void func1(int *a){
*a = 2;
func2(a);
}
int main(){
int a = 1;
func1(&a);
}
func2:
pushq %rbp
movq %rsp, %rbp
movq %rdi, -8(%rbp)
movq -8(%rbp), %rax
movl $3, (%rax)
nop
popq %rbp
ret
func1:
pushq %rbp
movq %rsp, %rbp
subq $8, %rsp
movq %rdi, -8(%rbp)
movq -8(%rbp), %rax
movl $2, (%rax)
movq -8(%rbp), %rax
movq %rax, %rdi
call func2
nop
leave
ret
main:
pushq %rbp
movq %rsp, %rbp
subq $16, %rsp
movl $1, -4(%rbp)
leaq -4(%rbp), %rax
movq %rax, %rdi
call func1
movl $0, %eax
leave
ret
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