#define NULL ((void *)0)
typedef unsigned long size_t; // Customize by platform.
typedef long intptr_t;
typedef unsigned long uintptr_t;
typedef long scalar_t__; // Either arithmetic or pointer type.
/* By default, we understand bool (as a convenience). */
typedef int bool;
#define false 0
#define true 1

/* Forward declarations */

/* Type definitions */

/* Variables and functions */
int /*<<< orphan*/ gets(char *);
int /*<<< orphan*/ printf(char *, ...);
int /*<<< orphan*/ strcpy(char *, char *);
int main() {
  char string[100];
  char backup[100];
  printf("请输入字符串 ==> ");
  gets(string);
  strcpy(backup, string);
  printf("初始字符串 %s \n", string);
  printf("备份字符串 %s \n", backup);
  return 0;
}


x86 assembly (clang, -O0):
<main>:
push   %rbp
mov    %rsp,%rbp
sub    $0xe0,%rsp
movl   $0x0,-0x4(%rbp)
lea    0xeb7(%rip),%rdi
mov    $0x0,%al
call   1040 <printf@plt>
lea    -0x70(%rbp),%rdi
call   1050 <gets@plt>
lea    -0xe0(%rbp),%rdi
lea    -0x70(%rbp),%rsi
call   1030 <strcpy@plt>
lea    -0x70(%rbp),%rsi
lea    0xea4(%rip),%rdi
mov    $0x0,%al
call   1040 <printf@plt>
lea    -0xe0(%rbp),%rsi
lea    0xea4(%rip),%rdi
mov    $0x0,%al
call   1040 <printf@plt>
xor    %eax,%eax
add    $0xe0,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<main>:
push   %r14
push   %rbx
sub    $0xd8,%rsp
lea    0xebf(%rip),%rdi
xor    %eax,%eax
call   1040 <printf@plt>
lea    0x70(%rsp),%rbx
mov    %rbx,%rdi
call   1050 <gets@plt>
mov    %rsp,%r14
mov    %r14,%rdi
mov    %rbx,%rsi
call   1030 <strcpy@plt>
lea    0xeae(%rip),%rdi
mov    %rbx,%rsi
xor    %eax,%eax
call   1040 <printf@plt>
lea    0xeb2(%rip),%rdi
mov    %r14,%rsi
xor    %eax,%eax
call   1040 <printf@plt>
xor    %eax,%eax
add    $0xd8,%rsp
pop    %rbx
pop    %r14
ret

LLVM IR (-O0):
@.str = [24 x i8] c"\E8\AF\B7\E8\BE\93\E5\85\A5\E5\AD\97\E7\AC\A6\E4\B8\B2 ==> \00"
@.str.1 = [21 x i8] c"\E5\88\9D\E5\A7\8B\E5\AD\97\E7\AC\A6\E4\B8\B2 %s \0A\00"
@.str.2 = [21 x i8] c"\E5\A4\87\E4\BB\BD\E5\AD\97\E7\AC\A6\E4\B8\B2 %s \0A\00"
define i32 @main() {
%1 = alloca i32
%2 = alloca [100 x i8]
%3 = alloca [100 x i8]
store i32 0, i32* %1
%4 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([24 x i8], [24 x i8]* @.str, i64 0, i64 0))
%5 = getelementptr inbounds [100 x i8], [100 x i8]* %2, i64 0, i64 0
%6 = call i32 @gets(i8* %5)
%7 = getelementptr inbounds [100 x i8], [100 x i8]* %3, i64 0, i64 0
%8 = getelementptr inbounds [100 x i8], [100 x i8]* %2, i64 0, i64 0
%9 = call i32 @strcpy(i8* %7, i8* %8)
%10 = getelementptr inbounds [100 x i8], [100 x i8]* %2, i64 0, i64 0
%11 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([21 x i8], [21 x i8]* @.str.1, i64 0, i64 0), i8* %10)
%12 = getelementptr inbounds [100 x i8], [100 x i8]* %3, i64 0, i64 0
%13 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([21 x i8], [21 x i8]* @.str.2, i64 0, i64 0), i8* %12)
ret i32 0
}

LLVM IR (-O2):
@.str = [24 x i8] c"\E8\AF\B7\E8\BE\93\E5\85\A5\E5\AD\97\E7\AC\A6\E4\B8\B2 ==> \00"
@.str.1 = [21 x i8] c"\E5\88\9D\E5\A7\8B\E5\AD\97\E7\AC\A6\E4\B8\B2 %s \0A\00"
@.str.2 = [21 x i8] c"\E5\A4\87\E4\BB\BD\E5\AD\97\E7\AC\A6\E4\B8\B2 %s \0A\00"
define i32 @main() {
%1 = alloca [100 x i8]
%2 = alloca [100 x i8]
%3 = getelementptr inbounds [100 x i8], [100 x i8]* %1, i64 0, i64 0
%4 = getelementptr inbounds [100 x i8], [100 x i8]* %2, i64 0, i64 0
%5 = tail call i32 (i8*, ...) @printf(i8* dereferenceable(1) getelementptr inbounds ([24 x i8], [24 x i8]* @.str, i64 0, i64 0))
%6 = call i32 @gets(i8* %3)
%7 = call i32 @strcpy(i8* %4, i8* %3)
%8 = call i32 (i8*, ...) @printf(i8* dereferenceable(1) getelementptr inbounds ([21 x i8], [21 x i8]* @.str.1, i64 0, i64 0), i8* %3)
%9 = call i32 (i8*, ...) @printf(i8* dereferenceable(1) getelementptr inbounds ([21 x i8], [21 x i8]* @.str.2, i64 0, i64 0), i8* %4)
ret i32 0
}