#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 *, int *);
int main() {
  int n, r;
  printf("Enter a number: \n");
  scanf("%d", &n);
  r = 0;
  while (n != 0) {
    r *= 10;
    r += n % 10;
    n /= 10;
  }
  printf("%d\n", r);
  return 0;
}


x86 assembly (clang, -O0):
<main>:
push   %rbp
mov    %rsp,%rbp
sub    $0x10,%rsp
movl   $0x0,-0x4(%rbp)
lea    0xeca(%rip),%rdi
mov    $0x0,%al
call   1030 <printf@plt>
lea    0xece(%rip),%rdi
lea    -0x8(%rbp),%rsi
call   1040 <scanf@plt>
movl   $0x0,-0xc(%rbp)
cmpl   $0x0,-0x8(%rbp)
je     1189 <main+0x69>
imul   $0xa,-0xc(%rbp),%eax
mov    %eax,-0xc(%rbp)
mov    -0x8(%rbp),%eax
mov    $0xa,%ecx
cltd
idiv   %ecx
add    -0xc(%rbp),%edx
mov    %edx,-0xc(%rbp)
mov    -0x8(%rbp),%eax
mov    $0xa,%ecx
cltd
idiv   %ecx
mov    %eax,-0x8(%rbp)
jmp    1154 <main+0x34>
mov    -0xc(%rbp),%esi
lea    0xe82(%rip),%rdi
mov    $0x0,%al
call   1030 <printf@plt>
xor    %eax,%eax
add    $0x10,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<main>:
push   %rax
lea    0xecf(%rip),%rdi
call   1030 <puts@plt>
lea    0xebc(%rip),%rdi
lea    0x4(%rsp),%rsi
call   1050 <scanf@plt>
mov    0x4(%rsp),%eax
xor    %esi,%esi
test   %eax,%eax
je     1193 <main+0x63>
nopl   0x0(%rax,%rax,1)
lea    (%rsi,%rsi,4),%ecx
movslq %eax,%rdx
imul   $0x66666667,%rdx,%rax
mov    %rax,%rsi
shr    $0x3f,%rsi
sar    $0x22,%rax
add    %esi,%eax
lea    (%rax,%rax,1),%esi
lea    (%rsi,%rsi,4),%esi
mov    %edx,%edi
sub    %esi,%edi
lea    (%rdi,%rcx,2),%esi
add    $0x9,%edx
cmp    $0x12,%edx
ja     1160 <main+0x30>
mov    %eax,0x4(%rsp)
lea    0xe69(%rip),%rdi
xor    %eax,%eax
call   1040 <printf@plt>
xor    %eax,%eax
pop    %rcx
ret

LLVM IR (-O0):
@.str = [18 x i8] c"Enter a number: \0A\00"
@.str.1 = [3 x i8] c"%d\00"
@.str.2 = [4 x i8] c"%d\0A\00"
define i32 @main() {
%1 = alloca i32
%2 = alloca i32
%3 = alloca i32
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 = call i32 @scanf(i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str.1, i64 0, i64 0), i32* %2)
store i32 0, i32* %3
br label %6
6: ; preds = %9, %0
%7 = load i32, i32* %2
%8 = icmp ne i32 %7, 0
br i1 %8, label %9, label %18
9: ; preds = %6
%10 = load i32, i32* %3
%11 = mul nsw i32 %10, 10
store i32 %11, i32* %3
%12 = load i32, i32* %2
%13 = srem i32 %12, 10
%14 = load i32, i32* %3
%15 = add nsw i32 %14, %13
store i32 %15, i32* %3
%16 = load i32, i32* %2
%17 = sdiv i32 %16, 10
store i32 %17, i32* %2
br label %6
18: ; preds = %6
%19 = load i32, i32* %3
%20 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([4 x i8], [4 x i8]* @.str.2, i64 0, i64 0), i32 %19)
ret i32 0
}

LLVM IR (-O2):
@.str.1 = [3 x i8] c"%d\00"
@.str.2 = [4 x i8] c"%d\0A\00"
@str = [17 x i8] c"Enter a number: \00"
define i32 @main() {
%1 = alloca i32
%2 = bitcast i32* %1 to i8*
%3 = tail call i32 @puts(i8* dereferenceable(1) getelementptr inbounds ([17 x i8], [17 x i8]* @str, i64 0, i64 0))
%4 = call i32 @scanf(i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str.1, i64 0, i64 0), i32* %1)
%5 = load i32, i32* %1
%6 = icmp eq i32 %5, 0
br i1 %6, label %17, label %7
7: ; preds = %0, %7
%8 = phi i32 [ %12, %7 ], [ 0, %0 ]
%9 = phi i32 [ %13, %7 ], [ %5, %0 ]
%10 = mul nsw i32 %8, 10
%11 = srem i32 %9, 10
%12 = add nsw i32 %10, %11
%13 = sdiv i32 %9, 10
%14 = add i32 %9, 9
%15 = icmp ult i32 %14, 19
br i1 %15, label %16, label %7
16: ; preds = %7
store i32 %13, i32* %1
br label %17
17: ; preds = %16, %0
%18 = phi i32 [ %12, %16 ], [ 0, %0 ]
%19 = call i32 (i8*, ...) @printf(i8* dereferenceable(1) getelementptr inbounds ([4 x i8], [4 x i8]* @.str.2, i64 0, i64 0), i32 %18)
ret i32 0
}