#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*/ printf(char *, ...);
int /*<<< orphan*/ scanf(char *, char *);
int /*<<< orphan*/ str_swap(char *, char *);
int main() {
  char str1[80], str2[80];
  printf("Input a string1: ");
  scanf("%s", str1);
  printf("Input a string2: ");
  scanf("%s", str2);
  str_swap(str1, str2);
  printf("string1: %s\n", str1);
  printf("string2: %s\n", str2);
  return 0;
}


x86 assembly (clang, -O0):
<main>:
push   %rbp
mov    %rsp,%rbp
sub    $0xb0,%rsp
movl   $0x0,-0x4(%rbp)
lea    0xeb7(%rip),%rdi
mov    $0x0,%al
call   1040 <printf@plt>
lea    -0x60(%rbp),%rsi
lea    0xeb7(%rip),%rdi
call   1050 <scanf@plt>
lea    0xeae(%rip),%rdi
mov    $0x0,%al
call   1040 <printf@plt>
lea    -0xb0(%rbp),%rsi
lea    0xe96(%rip),%rdi
call   1050 <scanf@plt>
lea    -0x60(%rbp),%rdi
lea    -0xb0(%rbp),%rsi
call   1030 <str_swap@plt>
lea    -0x60(%rbp),%rsi
lea    0xe8b(%rip),%rdi
mov    $0x0,%al
call   1040 <printf@plt>
lea    -0xb0(%rbp),%rsi
lea    0xe83(%rip),%rdi
mov    $0x0,%al
call   1040 <printf@plt>
xor    %eax,%eax
add    $0xb0,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<main>:
push   %r15
push   %r14
push   %rbx
sub    $0xa0,%rsp
lea    0xebd(%rip),%rdi
xor    %eax,%eax
call   1040 <printf@plt>
lea    0xec1(%rip),%r14
lea    0x50(%rsp),%r15
mov    %r14,%rdi
mov    %r15,%rsi
call   1050 <scanf@plt>
lea    0xead(%rip),%rdi
xor    %eax,%eax
call   1040 <printf@plt>
mov    %rsp,%rbx
mov    %r14,%rdi
mov    %rbx,%rsi
call   1050 <scanf@plt>
mov    %r15,%rdi
mov    %rbx,%rsi
call   1030 <str_swap@plt>
lea    0xe98(%rip),%rdi
mov    %r15,%rsi
xor    %eax,%eax
call   1040 <printf@plt>
lea    0xe94(%rip),%rdi
mov    %rbx,%rsi
xor    %eax,%eax
call   1040 <printf@plt>
xor    %eax,%eax
add    $0xa0,%rsp
pop    %rbx
pop    %r14
pop    %r15
ret

LLVM IR (-O0):
@.str = [18 x i8] c"Input a string1: \00"
@.str.1 = [3 x i8] c"%s\00"
@.str.2 = [18 x i8] c"Input a string2: \00"
@.str.3 = [13 x i8] c"string1: %s\0A\00"
@.str.4 = [13 x i8] c"string2: %s\0A\00"
define i32 @main() {
%1 = alloca i32
%2 = alloca [80 x i8]
%3 = alloca [80 x i8]
store i32 0, i32* %1
%4 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([18 x i8], [18 x i8]* @.str, i64 0, i64 0))
%5 = getelementptr inbounds [80 x i8], [80 x i8]* %2, i64 0, i64 0
%6 = call i32 @scanf(i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str.1, i64 0, i64 0), i8* %5)
%7 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([18 x i8], [18 x i8]* @.str.2, i64 0, i64 0))
%8 = getelementptr inbounds [80 x i8], [80 x i8]* %3, i64 0, i64 0
%9 = call i32 @scanf(i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str.1, i64 0, i64 0), i8* %8)
%10 = getelementptr inbounds [80 x i8], [80 x i8]* %2, i64 0, i64 0
%11 = getelementptr inbounds [80 x i8], [80 x i8]* %3, i64 0, i64 0
%12 = call i32 @str_swap(i8* %10, i8* %11)
%13 = getelementptr inbounds [80 x i8], [80 x i8]* %2, i64 0, i64 0
%14 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([13 x i8], [13 x i8]* @.str.3, i64 0, i64 0), i8* %13)
%15 = getelementptr inbounds [80 x i8], [80 x i8]* %3, i64 0, i64 0
%16 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([13 x i8], [13 x i8]* @.str.4, i64 0, i64 0), i8* %15)
ret i32 0
}

LLVM IR (-O2):
@.str = [18 x i8] c"Input a string1: \00"
@.str.1 = [3 x i8] c"%s\00"
@.str.2 = [18 x i8] c"Input a string2: \00"
@.str.3 = [13 x i8] c"string1: %s\0A\00"
@.str.4 = [13 x i8] c"string2: %s\0A\00"
define i32 @main() {
%1 = alloca [80 x i8]
%2 = alloca [80 x i8]
%3 = getelementptr inbounds [80 x i8], [80 x i8]* %1, i64 0, i64 0
%4 = getelementptr inbounds [80 x i8], [80 x i8]* %2, i64 0, i64 0
%5 = tail call i32 (i8*, ...) @printf(i8* dereferenceable(1) getelementptr inbounds ([18 x i8], [18 x i8]* @.str, i64 0, i64 0))
%6 = call i32 @scanf(i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str.1, i64 0, i64 0), i8* %3)
%7 = call i32 (i8*, ...) @printf(i8* dereferenceable(1) getelementptr inbounds ([18 x i8], [18 x i8]* @.str.2, i64 0, i64 0))
%8 = call i32 @scanf(i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str.1, i64 0, i64 0), i8* %4)
%9 = call i32 @str_swap(i8* %3, i8* %4)
%10 = call i32 (i8*, ...) @printf(i8* dereferenceable(1) getelementptr inbounds ([13 x i8], [13 x i8]* @.str.3, i64 0, i64 0), i8* %3)
%11 = call i32 (i8*, ...) @printf(i8* dereferenceable(1) getelementptr inbounds ([13 x i8], [13 x i8]* @.str.4, i64 0, i64 0), i8* %4)
ret i32 0
}