#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 */
long factorial(int);
int /*<<< orphan*/ printf(char *, ...);
int /*<<< orphan*/ scanf(char *, int *);
int main() {
  int n;
  long f;
  printf("inserisci un numero per trovarne il fattoriale\n");
  scanf("%d", &n);
  if (n < 0)
    printf("solo interi positivi.\n");
  else {
    f = factorial(n);
    printf("%d! = %ld\n", n, f);
  }
  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    0xedc(%rip),%rdi
lea    -0x8(%rbp),%rsi
call   1050 <scanf@plt>
cmpl   $0x0,-0x8(%rbp)
jge    117a <main+0x4a>
lea    0xec5(%rip),%rdi
mov    $0x0,%al
call   1040 <printf@plt>
jmp    119b <main+0x6b>
mov    -0x8(%rbp),%edi
call   1030 <factorial@plt>
mov    %rax,-0x10(%rbp)
mov    -0x8(%rbp),%esi
mov    -0x10(%rbp),%rdx
lea    0xeb6(%rip),%rdi
mov    $0x0,%al
call   1040 <printf@plt>
xor    %eax,%eax
add    $0x10,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<main>:
push   %rax
lea    0xec6(%rip),%rdi
call   1030 <puts@plt>
lea    0xeac(%rip),%rdi
lea    0x4(%rsp),%rsi
call   1060 <scanf@plt>
mov    0x4(%rsp),%edi
test   %edi,%edi
js     1182 <main+0x42>
call   1040 <factorial@plt>
mov    0x4(%rsp),%esi
lea    0xe8d(%rip),%rdi
mov    %rax,%rdx
xor    %eax,%eax
call   1050 <printf@plt>
jmp    118e <main+0x4e>
lea    0xeb4(%rip),%rdi
call   1030 <puts@plt>
xor    %eax,%eax
pop    %rcx
ret

LLVM IR (-O0):
@.str = [48 x i8] c"inserisci un numero per trovarne il fattoriale\0A\00"
@.str.1 = [3 x i8] c"%d\00"
@.str.2 = [23 x i8] c"solo interi positivi.\0A\00"
@.str.3 = [11 x i8] c"%d! = %ld\0A\00"
define i32 @main() {
%1 = alloca i32
%2 = alloca i32
%3 = alloca i64
store i32 0, i32* %1
%4 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([48 x i8], [48 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 = icmp slt i32 %6, 0
br i1 %7, label %8, label %10
8: ; preds = %0
%9 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([23 x i8], [23 x i8]* @.str.2, i64 0, i64 0))
br label %16
10: ; preds = %0
%11 = load i32, i32* %2
%12 = call i64 @factorial(i32 %11)
store i64 %12, i64* %3
%13 = load i32, i32* %2
%14 = load i64, i64* %3
%15 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([11 x i8], [11 x i8]* @.str.3, i64 0, i64 0), i32 %13, i64 %14)
br label %16
16: ; preds = %10, %8
ret i32 0
}

LLVM IR (-O2):
@.str.1 = [3 x i8] c"%d\00"
@.str.3 = [11 x i8] c"%d! = %ld\0A\00"
@str = [47 x i8] c"inserisci un numero per trovarne il fattoriale\00"
@str.4 = [22 x i8] c"solo interi positivi.\00"
define i32 @main() {
%1 = alloca i32
%2 = bitcast i32* %1 to i8*
%3 = tail call i32 @puts(i8* dereferenceable(1) getelementptr inbounds ([47 x i8], [47 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 slt i32 %5, 0
br i1 %6, label %7, label %9
7: ; preds = %0
%8 = call i32 @puts(i8* dereferenceable(1) getelementptr inbounds ([22 x i8], [22 x i8]* @str.4, i64 0, i64 0))
br label %13
9: ; preds = %0
%10 = call i64 @factorial(i32 %5)
%11 = load i32, i32* %1
%12 = call i32 (i8*, ...) @printf(i8* dereferenceable(1) getelementptr inbounds ([11 x i8], [11 x i8]* @.str.3, i64 0, i64 0), i32 %11, i64 %10)
br label %13
13: ; preds = %9, %7
ret i32 0
}