#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, b;
  printf("Enter a number: ");
  scanf("%d", &n);
  r = 0;
  b = n;
  while (b != 0) {
    r = r * 10 + b % 10;
    b /= 10;
  }
  if (r == n)
    printf("It is a palindrome.\n");
  else
    printf("It's not  a palindrome.");
  return 0;
}


x86 assembly (clang, -O0):
<main>:
push   %rbp
mov    %rsp,%rbp
sub    $0x20,%rsp
movl   $0x0,-0x4(%rbp)
lea    0xeca(%rip),%rdi
call   1030 <printf@plt>
lea    0xecf(%rip),%rdi
lea    -0x8(%rbp),%rsi
call   1040 <scanf@plt>
movl   $0x0,-0xc(%rbp)
mov    -0x8(%rbp),%eax
mov    %eax,-0x10(%rbp)
cmpl   $0x0,-0x10(%rbp)
je     118f <main+0x6f>
imul   $0xa,-0xc(%rbp),%eax
mov    %eax,-0x14(%rbp)
mov    -0x10(%rbp),%eax
mov    $0xa,%ecx
cltd
idiv   %ecx
mov    -0x14(%rbp),%eax
add    %edx,%eax
mov    %eax,-0xc(%rbp)
mov    -0x10(%rbp),%eax
mov    $0xa,%ecx
cltd
idiv   %ecx
mov    %eax,-0x10(%rbp)
jmp    1158 <main+0x38>
mov    -0xc(%rbp),%eax
cmp    -0x8(%rbp),%eax
jne    11ac <main+0x8c>
lea    0xe72(%rip),%rdi
call   1030 <printf@plt>
jmp    11b8 <main+0x98>
lea    0xe76(%rip),%rdi
call   1030 <printf@plt>
xor    %eax,%eax
add    $0x20,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<main>:
push   %rax
lea    0xec8(%rip),%rdi
call   1040 <printf@plt>
lea    0xecd(%rip),%rdi
lea    0x4(%rsp),%rsi
call   1050 <scanf@plt>
mov    0x4(%rsp),%r8d
xor    %edx,%edx
test   %r8d,%r8d
je     118f <main+0x5f>
mov    %r8d,%ecx
nopl   (%rax)
lea    (%rdx,%rdx,4),%edx
movslq %ecx,%rax
imul   $0x66666667,%rax,%rcx
mov    %rcx,%rdi
shr    $0x3f,%rdi
sar    $0x22,%rcx
add    %edi,%ecx
lea    (%rcx,%rcx,1),%edi
lea    (%rdi,%rdi,4),%edi
mov    %eax,%esi
sub    %edi,%esi
lea    (%rsi,%rdx,2),%edx
add    $0x9,%eax
cmp    $0x12,%eax
ja     1160 <main+0x30>
cmp    %r8d,%edx
jne    11a2 <main+0x72>
lea    0xe91(%rip),%rdi
call   1030 <puts@plt>
jmp    11ae <main+0x7e>
lea    0xe6b(%rip),%rdi
call   1040 <printf@plt>
xor    %eax,%eax
pop    %rcx
ret

LLVM IR (-O0):
@.str = [17 x i8] c"Enter a number: \00"
@.str.1 = [3 x i8] c"%d\00"
@.str.2 = [21 x i8] c"It is a palindrome.\0A\00"
@.str.3 = [24 x i8] c"It's not a palindrome.\00"
define i32 @main() {
%1 = alloca i32
%2 = alloca i32
%3 = alloca i32
%4 = alloca i32
store i32 0, i32* %1
%5 = call i32 @printf(i8* getelementptr inbounds ([17 x i8], [17 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), i32* %2)
store i32 0, i32* %3
%7 = load i32, i32* %2
store i32 %7, i32* %4
br label %8
8: ; preds = %11, %0
%9 = load i32, i32* %4
%10 = icmp ne i32 %9, 0
br i1 %10, label %11, label %19
11: ; preds = %8
%12 = load i32, i32* %3
%13 = mul nsw i32 %12, 10
%14 = load i32, i32* %4
%15 = srem i32 %14, 10
%16 = add nsw i32 %13, %15
store i32 %16, i32* %3
%17 = load i32, i32* %4
%18 = sdiv i32 %17, 10
store i32 %18, i32* %4
br label %8
19: ; preds = %8
%20 = load i32, i32* %3
%21 = load i32, i32* %2
%22 = icmp eq i32 %20, %21
br i1 %22, label %23, label %25
23: ; preds = %19
%24 = call i32 @printf(i8* getelementptr inbounds ([21 x i8], [21 x i8]* @.str.2, i64 0, i64 0))
br label %27
25: ; preds = %19
%26 = call i32 @printf(i8* getelementptr inbounds ([24 x i8], [24 x i8]* @.str.3, i64 0, i64 0))
br label %27
27: ; preds = %25, %23
ret i32 0
}

LLVM IR (-O2):
@.str = [17 x i8] c"Enter a number: \00"
@.str.1 = [3 x i8] c"%d\00"
@.str.3 = [24 x i8] c"It's not a palindrome.\00"
@str = [20 x i8] c"It is a palindrome.\00"
define i32 @main() {
%1 = alloca i32
%2 = bitcast i32* %1 to i8*
%3 = tail call i32 @printf(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 %16, label %7
7: ; preds = %0, %7
%8 = phi i32 [ %13, %7 ], [ %5, %0 ]
%9 = phi i32 [ %12, %7 ], [ 0, %0 ]
%10 = mul nsw i32 %9, 10
%11 = srem i32 %8, 10
%12 = add nsw i32 %11, %10
%13 = sdiv i32 %8, 10
%14 = add i32 %8, 9
%15 = icmp ult i32 %14, 19
br i1 %15, label %16, label %7
16: ; preds = %7, %0
%17 = phi i32 [ 0, %0 ], [ %12, %7 ]
%18 = icmp eq i32 %17, %5
br i1 %18, label %19, label %21
19: ; preds = %16
%20 = call i32 @puts(i8* dereferenceable(1) getelementptr inbounds ([20 x i8], [20 x i8]* @str, i64 0, i64 0))
br label %23
21: ; preds = %16
%22 = call i32 @printf(i8* dereferenceable(1) getelementptr inbounds ([24 x i8], [24 x i8]* @.str.3, i64 0, i64 0))
br label %23
23: ; preds = %21, %19
ret i32 0
}