#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 atoi(char *);
int factorial(int);
int /*<<< orphan*/ printf(char *, ...);
int main(int argc, char **argv) {
  if (argc != 2) {
    printf("Error: exactly one parameter is required!\n");
    return 1;
  }
  int n = atoi(argv[1]);
  int fact = factorial(n);
  printf(" fact(%i) = %i\n", n, fact);
  return 0;
}


x86 assembly (clang, -O0):
<main>:
push   %rbp
mov    %rsp,%rbp
sub    $0x20,%rsp
movl   $0x0,-0x4(%rbp)
mov    %edi,-0x8(%rbp)
mov    %rsi,-0x10(%rbp)
cmpl   $0x2,-0x8(%rbp)
je     116a <main+0x3a>
lea    0xea9(%rip),%rdi
mov    $0x0,%al
call   1040 <printf@plt>
movl   $0x1,-0x4(%rbp)
jmp    11a0 <main+0x70>
mov    -0x10(%rbp),%rax
mov    0x8(%rax),%rdi
call   1050 <atoi@plt>
mov    %eax,-0x14(%rbp)
mov    -0x14(%rbp),%edi
call   1030 <factorial@plt>
mov    %eax,-0x18(%rbp)
mov    -0x14(%rbp),%esi
mov    -0x18(%rbp),%edx
lea    0xe99(%rip),%rdi
mov    $0x0,%al
call   1040 <printf@plt>
movl   $0x0,-0x4(%rbp)
mov    -0x4(%rbp),%eax
add    $0x20,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<main>:
push   %rbp
push   %rbx
push   %rax
cmp    $0x2,%edi
jne    1170 <main+0x30>
mov    0x8(%rsi),%rdi
call   1060 <atoi@plt>
mov    %eax,%ebp
mov    %eax,%edi
call   1040 <factorial@plt>
lea    0xe9f(%rip),%rdi
xor    %ebx,%ebx
mov    %ebp,%esi
mov    %eax,%edx
xor    %eax,%eax
call   1050 <printf@plt>
jmp    1181 <main+0x41>
lea    0xe99(%rip),%rdi
call   1030 <puts@plt>
mov    $0x1,%ebx
mov    %ebx,%eax
add    $0x8,%rsp
pop    %rbx
pop    %rbp
ret

LLVM IR (-O0):
@.str = [43 x i8] c"Error: exactly one parameter is required!\0A\00"
@.str.1 = [16 x i8] c" fact(%i) = %i\0A\00"
define i32 @main(i32 %0, i8** %1) {
%3 = alloca i32
%4 = alloca i32
%5 = alloca i8**
%6 = alloca i32
%7 = alloca i32
store i32 0, i32* %3
store i32 %0, i32* %4
store i8** %1, i8*** %5
%8 = load i32, i32* %4
%9 = icmp ne i32 %8, 2
br i1 %9, label %10, label %12
10: ; preds = %2
%11 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([43 x i8], [43 x i8]* @.str, i64 0, i64 0))
store i32 1, i32* %3
br label %22
12: ; preds = %2
%13 = load i8**, i8*** %5
%14 = getelementptr inbounds i8*, i8** %13, i64 1
%15 = load i8*, i8** %14
%16 = call i32 @atoi(i8* %15)
store i32 %16, i32* %6
%17 = load i32, i32* %6
%18 = call i32 @factorial(i32 %17)
store i32 %18, i32* %7
%19 = load i32, i32* %6
%20 = load i32, i32* %7
%21 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([16 x i8], [16 x i8]* @.str.1, i64 0, i64 0), i32 %19, i32 %20)
store i32 0, i32* %3
br label %22
22: ; preds = %12, %10
%23 = load i32, i32* %3
ret i32 %23
}

LLVM IR (-O2):
@.str.1 = [16 x i8] c" fact(%i) = %i\0A\00"
@str = [42 x i8] c"Error: exactly one parameter is required!\00"
define i32 @main(i32 %0, i8** nocapture %1) {
%3 = icmp eq i32 %0, 2
br i1 %3, label %6, label %4
4: ; preds = %2
%5 = tail call i32 @puts(i8* dereferenceable(1) getelementptr inbounds ([42 x i8], [42 x i8]* @str, i64 0, i64 0))
br label %12
6: ; preds = %2
%7 = getelementptr inbounds i8*, i8** %1, i64 1
%8 = load i8*, i8** %7
%9 = tail call i32 @atoi(i8* %8)
%10 = tail call i32 @factorial(i32 %9)
%11 = tail call i32 (i8*, ...) @printf(i8* dereferenceable(1) getelementptr inbounds ([16 x i8], [16 x i8]* @.str.1, i64 0, i64 0), i32 %9, i32 %10)
br label %12
12: ; preds = %6, %4
%13 = phi i32 [ 1, %4 ], [ 0, %6 ]
ret i32 %13
}