#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 */
char *lookup(char *);
int /*<<< orphan*/ printf(char *, ...);
int main(int argc, char *argv[]) {
  if (argc != 2) {
    printf("Usage: ./file_extension-1 [extension]\n");
    return 1;
  }
  char *extension = argv[1];
  const char *type = lookup(extension);
  if (type == NULL) {
    printf("NULL\n");
    return 1;
  }
  printf("%s\n", type);
}


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     115a <main+0x3a>
lea    0xeb9(%rip),%rdi
mov    $0x0,%al
call   1030 <printf@plt>
movl   $0x1,-0x4(%rbp)
jmp    11aa <main+0x8a>
mov    -0x10(%rbp),%rax
mov    0x8(%rax),%rax
mov    %rax,-0x18(%rbp)
mov    -0x18(%rbp),%rdi
call   1040 <lookup@plt>
mov    %rax,-0x20(%rbp)
cmpq   $0x0,-0x20(%rbp)
jne    1198 <main+0x78>
lea    0xea2(%rip),%rdi
mov    $0x0,%al
call   1030 <printf@plt>
movl   $0x1,-0x4(%rbp)
jmp    11aa <main+0x8a>
mov    -0x20(%rbp),%rsi
lea    0xe8a(%rip),%rdi
mov    $0x0,%al
call   1030 <printf@plt>
mov    -0x4(%rbp),%eax
add    $0x20,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<main>:
push   %rax
cmp    $0x2,%edi
jne    1140 <main+0x20>
mov    0x8(%rsi),%rdi
call   1040 <lookup@plt>
test   %rax,%rax
je     1149 <main+0x29>
mov    %rax,%rdi
call   1030 <puts@plt>
xor    %eax,%eax
pop    %rcx
ret
lea    0xebe(%rip),%rdi
jmp    1150 <main+0x30>
lea    0xeb0(%rip),%rdi
call   1030 <puts@plt>
mov    $0x1,%eax
pop    %rcx
ret

LLVM IR (-O0):
@.str = [39 x i8] c"Usage: ./file_extension-1 [extension]\0A\00"
@.str.1 = [6 x i8] c"NULL\0A\00"
@.str.2 = [4 x i8] c"%s\0A\00"
define i32 @main(i32 %0, i8** %1) {
%3 = alloca i32
%4 = alloca i32
%5 = alloca i8**
%6 = alloca i8*
%7 = alloca i8*
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 ([39 x i8], [39 x i8]* @.str, i64 0, i64 0))
store i32 1, i32* %3
br label %25
12: ; preds = %2
%13 = load i8**, i8*** %5
%14 = getelementptr inbounds i8*, i8** %13, i64 1
%15 = load i8*, i8** %14
store i8* %15, i8** %6
%16 = load i8*, i8** %6
%17 = call i8* @lookup(i8* %16)
store i8* %17, i8** %7
%18 = load i8*, i8** %7
%19 = icmp eq i8* %18, null
br i1 %19, label %20, label %22
20: ; preds = %12
%21 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([6 x i8], [6 x i8]* @.str.1, i64 0, i64 0))
store i32 1, i32* %3
br label %25
22: ; preds = %12
%23 = load i8*, i8** %7
%24 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([4 x i8], [4 x i8]* @.str.2, i64 0, i64 0), i8* %23)
br label %25
25: ; preds = %22, %20, %10
%26 = load i32, i32* %3
ret i32 %26
}

LLVM IR (-O2):
@str = [5 x i8] c"NULL\00"
@str.3 = [38 x i8] c"Usage: ./file_extension-1 [extension]\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 ([38 x i8], [38 x i8]* @str.3, i64 0, i64 0))
br label %15
6: ; preds = %2
%7 = getelementptr inbounds i8*, i8** %1, i64 1
%8 = load i8*, i8** %7
%9 = tail call i8* @lookup(i8* %8)
%10 = icmp eq i8* %9, null
br i1 %10, label %11, label %13
11: ; preds = %6
%12 = tail call i32 @puts(i8* dereferenceable(1) getelementptr inbounds ([5 x i8], [5 x i8]* @str, i64 0, i64 0))
br label %15
13: ; preds = %6
%14 = tail call i32 @puts(i8* %9)
br label %15
15: ; preds = %11, %13, %4
%16 = phi i32 [ 1, %4 ], [ 1, %11 ], [ 0, %13 ]
ret i32 %16
}