#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 /*<<< orphan*/ O_RDONLY;
int /*<<< orphan*/ check(char *);
int /*<<< orphan*/ exit(int);
int open(char *, int /*<<< orphan*/);
int /*<<< orphan*/ perror(char *);
int /*<<< orphan*/ printf(char *, char *);
int read(int, char *, int);
int main(int argc, char *argv[]) {
  char buf[256] = {0};
  int fd;
  if (argc != 2) {
    printf("Usage: %s <file>\n", argv[0]);
    exit(-1);
  }
  if ((fd = open(argv[1], O_RDONLY)) == -1) {
    do {
      perror("open");
      exit(-1);
    } while (0);
    ;
  }
  if (read(fd, buf, 4) != 4) {
    do {
      perror("read");
      exit(-1);
    } while (0);
    ;
  }
  check(buf);
  return 0;
}


x86 assembly (clang, -O0):
<main>:
push   %rbp
mov    %rsp,%rbp
sub    $0x120,%rsp
movl   $0x0,-0x4(%rbp)
mov    %edi,-0x8(%rbp)
mov    %rsi,-0x10(%rbp)
lea    -0x110(%rbp),%rdi
xor    %esi,%esi
mov    $0x100,%edx
call   1040 <memset@plt>
cmpl   $0x2,-0x8(%rbp)
je     11c3 <main+0x53>
mov    -0x10(%rbp),%rax
mov    (%rax),%rsi
lea    0xe4c(%rip),%rdi
call   1030 <printf@plt>
mov    $0xffffffff,%edi
call   1090 <exit@plt>
mov    -0x10(%rbp),%rax
mov    0x8(%rax),%rdi
mov    0x2e16(%rip),%rax
mov    (%rax),%esi
call   1060 <open@plt>
mov    %eax,-0x114(%rbp)
cmp    $0xffffffff,%eax
jne    1203 <main+0x93>
jmp    11ed <main+0x7d>
lea    0xe1e(%rip),%rdi
call   1070 <perror@plt>
mov    $0xffffffff,%edi
call   1090 <exit@plt>
mov    -0x114(%rbp),%edi
lea    -0x110(%rbp),%rsi
mov    $0x4,%edx
call   1050 <read@plt>
cmp    $0x4,%eax
je     123e <main+0xce>
jmp    1228 <main+0xb8>
lea    0xde8(%rip),%rdi
call   1070 <perror@plt>
mov    $0xffffffff,%edi
call   1090 <exit@plt>
lea    -0x110(%rbp),%rdi
call   1080 <check@plt>
xor    %eax,%eax
add    $0x120,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<main>:
sub    $0x108,%rsp
xorps  %xmm0,%xmm0
movaps %xmm0,0xf0(%rsp)
movaps %xmm0,0xe0(%rsp)
movaps %xmm0,0xd0(%rsp)
movaps %xmm0,0xc0(%rsp)
movaps %xmm0,0xb0(%rsp)
movaps %xmm0,0xa0(%rsp)
movaps %xmm0,0x90(%rsp)
movaps %xmm0,0x80(%rsp)
movaps %xmm0,0x70(%rsp)
movaps %xmm0,0x60(%rsp)
movaps %xmm0,0x50(%rsp)
movaps %xmm0,0x40(%rsp)
movaps %xmm0,0x30(%rsp)
movaps %xmm0,0x20(%rsp)
movaps %xmm0,0x10(%rsp)
movaps %xmm0,(%rsp)
cmp    $0x2,%edi
jne    1213 <main+0xb3>
mov    0x8(%rsi),%rdi
mov    0x2e07(%rip),%rax
mov    (%rax),%esi
call   1050 <open@plt>
cmp    $0xffffffff,%eax
je     122c <main+0xcc>
mov    %rsp,%rsi
mov    %eax,%edi
mov    $0x4,%edx
call   1040 <read@plt>
cmp    $0x4,%eax
jne    1235 <main+0xd5>
mov    %rsp,%rdi
call   1070 <check@plt>
xor    %eax,%eax
add    $0x108,%rsp
ret
mov    (%rsi),%rsi
lea    0xde3(%rip),%rdi
call   1030 <printf@plt>
mov    $0xffffffff,%edi
call   1080 <exit@plt>
lea    0xddf(%rip),%rdi
jmp    123c <main+0xdc>
lea    0xddb(%rip),%rdi
call   1060 <perror@plt>
mov    $0xffffffff,%edi
call   1080 <exit@plt>

LLVM IR (-O0):
@.str = [18 x i8] c"Usage: %s <file>\0A\00"
@O_RDONLY = global i32 0
@.str.1 = [5 x i8] c"open\00"
@.str.2 = [5 x i8] c"read\00"
define i32 @main(i32 %0, i8** %1) {
%3 = alloca i32
%4 = alloca i32
%5 = alloca i8**
%6 = alloca [256 x i8]
%7 = alloca i32
store i32 0, i32* %3
store i32 %0, i32* %4
store i8** %1, i8*** %5
%8 = bitcast [256 x i8]* %6 to i8*
%9 = load i32, i32* %4
%10 = icmp ne i32 %9, 2
br i1 %10, label %11, label %17
11: ; preds = %2
%12 = load i8**, i8*** %5
%13 = getelementptr inbounds i8*, i8** %12, i64 0
%14 = load i8*, i8** %13
%15 = call i32 @printf(i8* getelementptr inbounds ([18 x i8], [18 x i8]* @.str, i64 0, i64 0), i8* %14)
%16 = call i32 @exit(i32 -1)
unreachable
17: ; preds = %2
%18 = load i8**, i8*** %5
%19 = getelementptr inbounds i8*, i8** %18, i64 1
%20 = load i8*, i8** %19
%21 = load i32, i32* @O_RDONLY
%22 = call i32 @open(i8* %20, i32 %21)
store i32 %22, i32* %7
%23 = icmp eq i32 %22, -1
br i1 %23, label %24, label %29
24: ; preds = %17
br label %25
25: ; preds = %24
%26 = call i32 @perror(i8* getelementptr inbounds ([5 x i8], [5 x i8]* @.str.1, i64 0, i64 0))
%27 = call i32 @exit(i32 -1)
unreachable
28: ; No predecessors!
br label %29
29: ; preds = %28, %17
%30 = load i32, i32* %7
%31 = getelementptr inbounds [256 x i8], [256 x i8]* %6, i64 0, i64 0
%32 = call i32 @read(i32 %30, i8* %31, i32 4)
%33 = icmp ne i32 %32, 4
br i1 %33, label %34, label %39
34: ; preds = %29
br label %35
35: ; preds = %34
%36 = call i32 @perror(i8* getelementptr inbounds ([5 x i8], [5 x i8]* @.str.2, i64 0, i64 0))
%37 = call i32 @exit(i32 -1)
unreachable
38: ; No predecessors!
br label %39
39: ; preds = %38, %29
%40 = getelementptr inbounds [256 x i8], [256 x i8]* %6, i64 0, i64 0
%41 = call i32 @check(i8* %40)
ret i32 0
}

LLVM IR (-O2):
@.str = [18 x i8] c"Usage: %s <file>\0A\00"
@O_RDONLY = global i32 0
@.str.1 = [5 x i8] c"open\00"
@.str.2 = [5 x i8] c"read\00"
define i32 @main(i32 %0, i8** nocapture %1) {
%3 = alloca [256 x i8]
%4 = getelementptr inbounds [256 x i8], [256 x i8]* %3, i64 0, i64 0
%5 = icmp eq i32 %0, 2
br i1 %5, label %10, label %6
6: ; preds = %2
%7 = load i8*, i8** %1
%8 = tail call i32 @printf(i8* getelementptr inbounds ([18 x i8], [18 x i8]* @.str, i64 0, i64 0), i8* %7)
%9 = tail call i32 @exit(i32 -1)
unreachable
10: ; preds = %2
%11 = getelementptr inbounds i8*, i8** %1, i64 1
%12 = load i8*, i8** %11
%13 = load i32, i32* @O_RDONLY
%14 = tail call i32 @open(i8* %12, i32 %13)
%15 = icmp eq i32 %14, -1
br i1 %15, label %16, label %19
16: ; preds = %10
%17 = tail call i32 @perror(i8* getelementptr inbounds ([5 x i8], [5 x i8]* @.str.1, i64 0, i64 0))
%18 = tail call i32 @exit(i32 -1)
unreachable
19: ; preds = %10
%20 = call i32 @read(i32 %14, i8* %4, i32 4)
%21 = icmp eq i32 %20, 4
br i1 %21, label %25, label %22
22: ; preds = %19
%23 = tail call i32 @perror(i8* getelementptr inbounds ([5 x i8], [5 x i8]* @.str.2, i64 0, i64 0))
%24 = tail call i32 @exit(i32 -1)
unreachable
25: ; preds = %19
%26 = call i32 @check(i8* %4)
ret i32 0
}