#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 *, ...);
void main() {
  char str[50];
  int i = 0;
  printf("Enter string:");
  gets(str);
  printf("\nOutput:");
  while (str[i] != '\0') {
    printf("%c", str[i]);
    i++;
  }
  printf("\n");
}


x86 assembly (clang, -O0):
<main>:
push   %rbp
mov    %rsp,%rbp
sub    $0x50,%rsp
movl   $0x0,-0x44(%rbp)
lea    0xeca(%rip),%rdi
mov    $0x0,%al
call   1030 <printf@plt>
lea    -0x40(%rbp),%rdi
call   1040 <gets@plt>
lea    0xec1(%rip),%rdi
mov    $0x0,%al
call   1030 <printf@plt>
movslq -0x44(%rbp),%rax
movsbl -0x40(%rbp,%rax,1),%eax
cmp    $0x0,%eax
je     118b <main+0x6b>
movslq -0x44(%rbp),%rax
movsbl -0x40(%rbp,%rax,1),%esi
lea    0xea1(%rip),%rdi
mov    $0x0,%al
call   1030 <printf@plt>
mov    -0x44(%rbp),%eax
add    $0x1,%eax
mov    %eax,-0x44(%rbp)
jmp    1154 <main+0x34>
lea    0xe88(%rip),%rdi
mov    $0x0,%al
call   1030 <printf@plt>
add    $0x50,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<main>:
push   %rbx
sub    $0x40,%rsp
lea    0xec4(%rip),%rdi
xor    %eax,%eax
call   1040 <printf@plt>
mov    %rsp,%rdi
call   1050 <gets@plt>
lea    0xebc(%rip),%rdi
xor    %eax,%eax
call   1040 <printf@plt>
mov    (%rsp),%al
test   %al,%al
je     1183 <main+0x53>
lea    0x1(%rsp),%rbx
cs nopw 0x0(%rax,%rax,1)
nop
movsbl %al,%edi
call   1030 <putchar@plt>
movzbl (%rbx),%eax
add    $0x1,%rbx
test   %al,%al
jne    1170 <main+0x40>
mov    $0xa,%edi
call   1030 <putchar@plt>
add    $0x40,%rsp
pop    %rbx
ret

LLVM IR (-O0):
@.str = [14 x i8] c"Enter string:\00"
@.str.1 = [9 x i8] c"\0AOutput:\00"
@.str.2 = [3 x i8] c"%c\00"
@.str.3 = [2 x i8] c"\0A\00"
define void @main() {
%1 = alloca [50 x i8]
%2 = alloca i32
store i32 0, i32* %2
%3 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([14 x i8], [14 x i8]* @.str, i64 0, i64 0))
%4 = getelementptr inbounds [50 x i8], [50 x i8]* %1, i64 0, i64 0
%5 = call i32 @gets(i8* %4)
%6 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([9 x i8], [9 x i8]* @.str.1, i64 0, i64 0))
br label %7
7: ; preds = %14, %0
%8 = load i32, i32* %2
%9 = sext i32 %8 to i64
%10 = getelementptr inbounds [50 x i8], [50 x i8]* %1, i64 0, i64 %9
%11 = load i8, i8* %10
%12 = sext i8 %11 to i32
%13 = icmp ne i32 %12, 0
br i1 %13, label %14, label %23
14: ; preds = %7
%15 = load i32, i32* %2
%16 = sext i32 %15 to i64
%17 = getelementptr inbounds [50 x i8], [50 x i8]* %1, i64 0, i64 %16
%18 = load i8, i8* %17
%19 = sext i8 %18 to i32
%20 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str.2, i64 0, i64 0), i32 %19)
%21 = load i32, i32* %2
%22 = add nsw i32 %21, 1
store i32 %22, i32* %2
br label %7
23: ; preds = %7
%24 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([2 x i8], [2 x i8]* @.str.3, i64 0, i64 0))
ret void
}

LLVM IR (-O2):
@.str = [14 x i8] c"Enter string:\00"
@.str.1 = [9 x i8] c"\0AOutput:\00"
define void @main() {
%1 = alloca [50 x i8]
%2 = getelementptr inbounds [50 x i8], [50 x i8]* %1, i64 0, i64 0
%3 = tail call i32 (i8*, ...) @printf(i8* dereferenceable(1) getelementptr inbounds ([14 x i8], [14 x i8]* @.str, i64 0, i64 0))
%4 = call i32 @gets(i8* %2)
%5 = call i32 (i8*, ...) @printf(i8* dereferenceable(1) getelementptr inbounds ([9 x i8], [9 x i8]* @.str.1, i64 0, i64 0))
%6 = load i8, i8* %2
%7 = icmp eq i8 %6, 0
br i1 %7, label %17, label %8
8: ; preds = %0, %8
%9 = phi i64 [ %13, %8 ], [ 0, %0 ]
%10 = phi i8 [ %15, %8 ], [ %6, %0 ]
%11 = sext i8 %10 to i32
%12 = call i32 @putchar(i32 %11)
%13 = add nuw i64 %9, 1
%14 = getelementptr inbounds [50 x i8], [50 x i8]* %1, i64 0, i64 %13
%15 = load i8, i8* %14
%16 = icmp eq i8 %15, 0
br i1 %16, label %17, label %8
17: ; preds = %8, %0
%18 = call i32 @putchar(i32 10)
ret void
}