#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 */
typedef int uint64_t;

/* Variables and functions */
int _fac(int const);
uint64_t factorial(const uint64_t a) {
  switch (a) {
  case 1:
    return 1;
  case 2:
    return 2;
  case 3:
    return 6;
  case 4:
    return 24;
  case 5:
    return 120;
  case 6:
    return 720;
  case 7:
    return 5040;
  case 8:
    return 40320;
  case 9:
    return 362880;
  case 10:
    return 3628800;
  default:
    return _fac(a);
  }
}


x86 assembly (clang, -O0):
<factorial>:
push   %rbp
mov    %rsp,%rbp
sub    $0x10,%rsp
mov    %edi,-0x8(%rbp)
mov    -0x8(%rbp),%eax
add    $0xffffffff,%eax
mov    %eax,%ecx
mov    %rcx,-0x10(%rbp)
sub    $0x9,%eax
ja     11bc <factorial+0xac>
mov    -0x10(%rbp),%rax
lea    0xec5(%rip),%rcx
movslq (%rcx,%rax,4),%rax
add    %rcx,%rax
jmp    *%rax
movl   $0x1,-0x4(%rbp)
jmp    11c7 <factorial+0xb7>
movl   $0x2,-0x4(%rbp)
jmp    11c7 <factorial+0xb7>
movl   $0x6,-0x4(%rbp)
jmp    11c7 <factorial+0xb7>
movl   $0x18,-0x4(%rbp)
jmp    11c7 <factorial+0xb7>
movl   $0x78,-0x4(%rbp)
jmp    11c7 <factorial+0xb7>
movl   $0x2d0,-0x4(%rbp)
jmp    11c7 <factorial+0xb7>
movl   $0x13b0,-0x4(%rbp)
jmp    11c7 <factorial+0xb7>
movl   $0x9d80,-0x4(%rbp)
jmp    11c7 <factorial+0xb7>
movl   $0x58980,-0x4(%rbp)
jmp    11c7 <factorial+0xb7>
movl   $0x375f00,-0x4(%rbp)
jmp    11c7 <factorial+0xb7>
mov    -0x8(%rbp),%edi
call   1030 <_fac@plt>
mov    %eax,-0x4(%rbp)
mov    -0x4(%rbp),%eax
add    $0x10,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<factorial>:
lea    -0x1(%rdi),%eax
cmp    $0xa,%eax
jae    1125 <factorial+0x15>
cltq
lea    0xedf(%rip),%rcx
mov    (%rcx,%rax,4),%eax
ret
jmp    1030 <_fac@plt>

LLVM IR (-O0):
define i32 @factorial(i32 %0) {
%2 = alloca i32
%3 = alloca i32
store i32 %0, i32* %3
%4 = load i32, i32* %3
switch i32 %4, label %15 [
i32 1, label %5
i32 2, label %6
i32 3, label %7
i32 4, label %8
i32 5, label %9
i32 6, label %10
i32 7, label %11
i32 8, label %12
i32 9, label %13
i32 10, label %14
]
5: ; preds = %1
store i32 1, i32* %2
br label %18
6: ; preds = %1
store i32 2, i32* %2
br label %18
7: ; preds = %1
store i32 6, i32* %2
br label %18
8: ; preds = %1
store i32 24, i32* %2
br label %18
9: ; preds = %1
store i32 120, i32* %2
br label %18
10: ; preds = %1
store i32 720, i32* %2
br label %18
11: ; preds = %1
store i32 5040, i32* %2
br label %18
12: ; preds = %1
store i32 40320, i32* %2
br label %18
13: ; preds = %1
store i32 362880, i32* %2
br label %18
14: ; preds = %1
store i32 3628800, i32* %2
br label %18
15: ; preds = %1
%16 = load i32, i32* %3
%17 = call i32 @_fac(i32 %16)
store i32 %17, i32* %2
br label %18
18: ; preds = %15, %14, %13, %12, %11, %10, %9, %8, %7, %6, %5
%19 = load i32, i32* %2
ret i32 %19
}

LLVM IR (-O2):
@switch.table.factorial = [10 x i32] [i32 1, i32 2, i32 6, i32 24, i32 120, i32 720, i32 5040, i32 40320, i32 362880, i32 3628800]
define i32 @factorial(i32 %0) {
%2 = add i32 %0, -1
%3 = icmp ult i32 %2, 10
br i1 %3, label %6, label %4
4: ; preds = %1
%5 = tail call i32 @_fac(i32 %0)
br label %10
6: ; preds = %1
%7 = sext i32 %2 to i64
%8 = getelementptr inbounds [10 x i32], [10 x i32]* @switch.table.factorial, i64 0, i64 %7
%9 = load i32, i32* %8
br label %10
10: ; preds = %6, %4
%11 = phi i32 [ %5, %4 ], [ %9, %6 ]
ret i32 %11
}