#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[]) {
  int n;
  if (argc < 2) {
    printf("Usage: %s <n>\n", argv[0]);
    n = 3;
  } else {
    n = atoi(argv[1]);
  }
  printf("\nFactorial(%d) = %d\n", n, factorial(n));
}


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)
jge    1171 <main+0x41>
mov    -0x10(%rbp),%rax
mov    (%rax),%rsi
lea    0xea2(%rip),%rdi
mov    $0x0,%al
call   1040 <printf@plt>
movl   $0x3,-0x14(%rbp)
jmp    1181 <main+0x51>
mov    -0x10(%rbp),%rax
mov    0x8(%rax),%rdi
call   1050 <atoi@plt>
mov    %eax,-0x14(%rbp)
mov    -0x14(%rbp),%eax
mov    %eax,-0x18(%rbp)
mov    -0x14(%rbp),%edi
call   1030 <factorial@plt>
mov    -0x18(%rbp),%esi
mov    %eax,%edx
lea    0xe74(%rip),%rdi
mov    $0x0,%al
call   1040 <printf@plt>
mov    -0x4(%rbp),%eax
add    $0x20,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<main>:
push   %rbx
cmp    $0x1,%edi
jg     114e <main+0x1e>
mov    (%rsi),%rsi
lea    0xec0(%rip),%rdi
xor    %eax,%eax
call   1040 <printf@plt>
mov    $0x3,%ebx
jmp    1159 <main+0x29>
mov    0x8(%rsi),%rdi
call   1050 <atoi@plt>
mov    %eax,%ebx
mov    %ebx,%edi
call   1030 <factorial@plt>
lea    0xea8(%rip),%rdi
mov    %ebx,%esi
mov    %eax,%edx
xor    %eax,%eax
call   1040 <printf@plt>
xor    %eax,%eax
pop    %rbx
ret

LLVM IR (-O0):
@.str = [15 x i8] c"Usage: %s <n>\0A\00"
@.str.1 = [21 x i8] c"\0AFactorial(%d) = %d\0A\00"
define i32 @main(i32 %0, i8** %1) {
%3 = alloca i32
%4 = alloca i32
%5 = alloca i8**
%6 = alloca i32
store i32 0, i32* %3
store i32 %0, i32* %4
store i8** %1, i8*** %5
%7 = load i32, i32* %4
%8 = icmp slt i32 %7, 2
br i1 %8, label %9, label %14
9: ; preds = %2
%10 = load i8**, i8*** %5
%11 = getelementptr inbounds i8*, i8** %10, i64 0
%12 = load i8*, i8** %11
%13 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([15 x i8], [15 x i8]* @.str, i64 0, i64 0), i8* %12)
store i32 3, i32* %6
br label %19
14: ; preds = %2
%15 = load i8**, i8*** %5
%16 = getelementptr inbounds i8*, i8** %15, i64 1
%17 = load i8*, i8** %16
%18 = call i32 @atoi(i8* %17)
store i32 %18, i32* %6
br label %19
19: ; preds = %14, %9
%20 = load i32, i32* %6
%21 = load i32, i32* %6
%22 = call i32 @factorial(i32 %21)
%23 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([21 x i8], [21 x i8]* @.str.1, i64 0, i64 0), i32 %20, i32 %22)
%24 = load i32, i32* %3
ret i32 %24
}

LLVM IR (-O2):
@.str = [15 x i8] c"Usage: %s <n>\0A\00"
@.str.1 = [21 x i8] c"\0AFactorial(%d) = %d\0A\00"
define i32 @main(i32 %0, i8** nocapture %1) {
%3 = icmp slt i32 %0, 2
br i1 %3, label %4, label %7
4: ; preds = %2
%5 = load i8*, i8** %1
%6 = tail call i32 (i8*, ...) @printf(i8* dereferenceable(1) getelementptr inbounds ([15 x i8], [15 x i8]* @.str, i64 0, i64 0), i8* %5)
br label %11
7: ; preds = %2
%8 = getelementptr inbounds i8*, i8** %1, i64 1
%9 = load i8*, i8** %8
%10 = tail call i32 @atoi(i8* %9)
br label %11
11: ; preds = %7, %4
%12 = phi i32 [ 3, %4 ], [ %10, %7 ]
%13 = tail call i32 @factorial(i32 %12)
%14 = tail call i32 (i8*, ...) @printf(i8* dereferenceable(1) getelementptr inbounds ([21 x i8], [21 x i8]* @.str.1, i64 0, i64 0), i32 %12, i32 %13)
ret i32 0
}