#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 /*<<< orphan*/ showbits(unsigned int);
int main() {
  unsigned int num;
  int pos;
  printf("Enter a number:");
  scanf("%d", &num);
  showbits(num);
  printf("Enter the position of bit to set:");
  scanf("%d", &pos);
  printf("Number after setting a bit at position %d:\n", pos);
  showbits((num | (1 << pos)));
  return 0;
}


x86 assembly (clang, -O0):
<main>:
push   %rbp
mov    %rsp,%rbp
sub    $0x10,%rsp
movl   $0x0,-0x4(%rbp)
lea    0xeba(%rip),%rdi
mov    $0x0,%al
call   1040 <printf@plt>
lea    0xebc(%rip),%rdi
lea    -0x8(%rbp),%rsi
mov    $0x0,%al
call   1050 <scanf@plt>
mov    -0x8(%rbp),%edi
call   1030 <showbits@plt>
lea    0xea5(%rip),%rdi
mov    $0x0,%al
call   1040 <printf@plt>
lea    0xe94(%rip),%rdi
lea    -0xc(%rbp),%rsi
mov    $0x0,%al
call   1050 <scanf@plt>
mov    -0xc(%rbp),%esi
lea    0xea4(%rip),%rdi
mov    $0x0,%al
call   1040 <printf@plt>
mov    -0x8(%rbp),%edi
mov    -0xc(%rbp),%ecx
mov    $0x1,%eax
shl    %cl,%eax
or     %eax,%edi
call   1030 <showbits@plt>
xor    %eax,%eax
add    $0x10,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<main>:
push   %rbx
sub    $0x10,%rsp
lea    0xec4(%rip),%rdi
xor    %eax,%eax
call   1040 <printf@plt>
lea    0xec6(%rip),%rbx
lea    0xc(%rsp),%rsi
mov    %rbx,%rdi
xor    %eax,%eax
call   1050 <scanf@plt>
mov    0xc(%rsp),%edi
call   1030 <showbits@plt>
lea    0xeaa(%rip),%rdi
xor    %eax,%eax
call   1040 <printf@plt>
lea    0x8(%rsp),%rsi
mov    %rbx,%rdi
xor    %eax,%eax
call   1050 <scanf@plt>
mov    0x8(%rsp),%esi
lea    0xeab(%rip),%rdi
xor    %eax,%eax
call   1040 <printf@plt>
mov    0xc(%rsp),%edi
mov    0x8(%rsp),%al
bts    %eax,%edi
call   1030 <showbits@plt>
xor    %eax,%eax
add    $0x10,%rsp
pop    %rbx
ret

LLVM IR (-O0):
@.str = [16 x i8] c"Enter a number:\00"
@.str.1 = [3 x i8] c"%d\00"
@.str.2 = [34 x i8] c"Enter the position of bit to set:\00"
@.str.3 = [44 x i8] c"Number after setting a bit at position %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 ([16 x i8], [16 x i8]* @.str, i64 0, i64 0))
%5 = call i32 (i8*, ...) @scanf(i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str.1, i64 0, i64 0), i32* %2)
%6 = load i32, i32* %2
%7 = call i32 @showbits(i32 %6)
%8 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([34 x i8], [34 x i8]* @.str.2, i64 0, i64 0))
%9 = call i32 (i8*, ...) @scanf(i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str.1, i64 0, i64 0), i32* %3)
%10 = load i32, i32* %3
%11 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([44 x i8], [44 x i8]* @.str.3, i64 0, i64 0), i32 %10)
%12 = load i32, i32* %2
%13 = load i32, i32* %3
%14 = shl i32 1, %13
%15 = or i32 %12, %14
%16 = call i32 @showbits(i32 %15)
ret i32 0
}

LLVM IR (-O2):
@.str = [16 x i8] c"Enter a number:\00"
@.str.1 = [3 x i8] c"%d\00"
@.str.2 = [34 x i8] c"Enter the position of bit to set:\00"
@.str.3 = [44 x i8] c"Number after setting a bit at position %d:\0A\00"
define i32 @main() {
%1 = alloca i32
%2 = alloca i32
%3 = bitcast i32* %1 to i8*
%4 = bitcast i32* %2 to i8*
%5 = tail call i32 (i8*, ...) @printf(i8* dereferenceable(1) getelementptr inbounds ([16 x i8], [16 x i8]* @.str, i64 0, i64 0))
%6 = call i32 (i8*, ...) @scanf(i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str.1, i64 0, i64 0), i32* %1)
%7 = load i32, i32* %1
%8 = call i32 @showbits(i32 %7)
%9 = call i32 (i8*, ...) @printf(i8* dereferenceable(1) getelementptr inbounds ([34 x i8], [34 x i8]* @.str.2, i64 0, i64 0))
%10 = call i32 (i8*, ...) @scanf(i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str.1, i64 0, i64 0), i32* %2)
%11 = load i32, i32* %2
%12 = call i32 (i8*, ...) @printf(i8* dereferenceable(1) getelementptr inbounds ([44 x i8], [44 x i8]* @.str.3, i64 0, i64 0), i32 %11)
%13 = load i32, i32* %1
%14 = load i32, i32* %2
%15 = shl nuw i32 1, %14
%16 = or i32 %15, %13
%17 = call i32 @showbits(i32 %16)
ret i32 0
}