#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 */
unsigned long long f(unsigned int);
int /*<<< orphan*/ printf(char *, unsigned long long);
int /*<<< orphan*/ puts(char *);
int /*<<< orphan*/ scanf(char *, unsigned int *);
int main(void) {
  unsigned int n;
  unsigned long long result;
  puts("the positive n.");
  scanf("%u", &n);
  result = f(n);
  switch (result) {
  case 0:
    puts("Overflow.");
    break;
  default:
    printf("Result: %lld.\n", result);
    break;
  }
  return 0;
}


x86 assembly (clang, -O0):
<main>:
push   %rbp
mov    %rsp,%rbp
sub    $0x10,%rsp
movl   $0x0,-0x4(%rbp)
lea    0xeaa(%rip),%rdi
call   1030 <puts@plt>
lea    0xeae(%rip),%rdi
lea    -0x8(%rbp),%rsi
call   1060 <scanf@plt>
mov    -0x8(%rbp),%edi
call   1040 <f@plt>
mov    %rax,-0x10(%rbp)
mov    -0x10(%rbp),%rax
test   %rax,%rax
jne    119a <main+0x5a>
jmp    1189 <main+0x49>
lea    0xe83(%rip),%rdi
call   1030 <puts@plt>
jmp    11aa <main+0x6a>
mov    -0x10(%rbp),%rsi
lea    0xe78(%rip),%rdi
call   1050 <printf@plt>
xor    %eax,%eax
add    $0x10,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<main>:
push   %rax
lea    0xeb8(%rip),%rdi
call   1030 <puts@plt>
lea    0xebc(%rip),%rdi
lea    0x4(%rsp),%rsi
call   1060 <scanf@plt>
mov    0x4(%rsp),%edi
call   1040 <f@plt>
test   %rax,%rax
je     117d <main+0x3d>
lea    0xeaa(%rip),%rdi
mov    %rax,%rsi
call   1050 <printf@plt>
jmp    1189 <main+0x49>
lea    0xe8f(%rip),%rdi
call   1030 <puts@plt>
xor    %eax,%eax
pop    %rcx
ret

LLVM IR (-O0):
@.str = [16 x i8] c"the positive n.\00"
@.str.1 = [3 x i8] c"%u\00"
@.str.2 = [10 x i8] c"Overflow.\00"
@.str.3 = [15 x i8] c"Result: %lld.\0A\00"
define i32 @main() {
%1 = alloca i32
%2 = alloca i32
%3 = alloca i64
store i32 0, i32* %1
%4 = call i32 @puts(i8* getelementptr inbounds ([16 x i8], [16 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)
%6 = load i32, i32* %2
%7 = call i64 @f(i32 %6)
store i64 %7, i64* %3
%8 = load i64, i64* %3
switch i64 %8, label %11 [
i64 0, label %9
]
9: ; preds = %0
%10 = call i32 @puts(i8* getelementptr inbounds ([10 x i8], [10 x i8]* @.str.2, i64 0, i64 0))
br label %14
11: ; preds = %0
%12 = load i64, i64* %3
%13 = call i32 @printf(i8* getelementptr inbounds ([15 x i8], [15 x i8]* @.str.3, i64 0, i64 0), i64 %12)
br label %14
14: ; preds = %11, %9
ret i32 0
}

LLVM IR (-O2):
@.str = [16 x i8] c"the positive n.\00"
@.str.1 = [3 x i8] c"%u\00"
@.str.2 = [10 x i8] c"Overflow.\00"
@.str.3 = [15 x i8] c"Result: %lld.\0A\00"
define i32 @main() {
%1 = alloca i32
%2 = bitcast i32* %1 to i8*
%3 = tail call i32 @puts(i8* dereferenceable(1) getelementptr inbounds ([16 x i8], [16 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 = call i64 @f(i32 %5)
%7 = icmp eq i64 %6, 0
br i1 %7, label %8, label %10
8: ; preds = %0
%9 = call i32 @puts(i8* dereferenceable(1) getelementptr inbounds ([10 x i8], [10 x i8]* @.str.2, i64 0, i64 0))
br label %12
10: ; preds = %0
%11 = call i32 @printf(i8* getelementptr inbounds ([15 x i8], [15 x i8]* @.str.3, i64 0, i64 0), i64 %6)
br label %12
12: ; preds = %10, %8
ret i32 0
}