#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 /*<<< orphan*/ FILE;

/* Variables and functions */
int /*<<< orphan*/ *fopen(char *, char *);
int /*<<< orphan*/ perror(char *);
int /*<<< orphan*/ printf(char *);
int main(int argc, char *argv[]) {
  if (argc != 2) {
    printf("enter file name\n");
    return 1;
  }
  FILE *mystream = fopen(argv[1], "r");
  if (mystream == NULL) {
    perror("open file");
    return 1;
  }
  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     1168 <main+0x38>
lea    0xea9(%rip),%rdi
call   1030 <printf@plt>
movl   $0x1,-0x4(%rbp)
jmp    11aa <main+0x7a>
mov    -0x10(%rbp),%rax
mov    0x8(%rax),%rdi
lea    0xe9a(%rip),%rsi
call   1040 <fopen@plt>
mov    %rax,-0x18(%rbp)
cmpq   $0x0,-0x18(%rbp)
jne    11a3 <main+0x73>
lea    0xe81(%rip),%rdi
call   1050 <perror@plt>
movl   $0x1,-0x4(%rbp)
jmp    11aa <main+0x7a>
movl   $0x0,-0x4(%rbp)
mov    -0x4(%rbp),%eax
add    $0x20,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<main>:
push   %rax
cmp    $0x2,%edi
jne    1152 <main+0x22>
mov    0x8(%rsi),%rdi
lea    0xebf(%rip),%rsi
call   1040 <fopen@plt>
mov    %rax,%rcx
xor    %eax,%eax
test   %rcx,%rcx
je     1165 <main+0x35>
pop    %rcx
ret
lea    0xeb3(%rip),%rdi
call   1030 <puts@plt>
mov    $0x1,%eax
pop    %rcx
ret
lea    0xe96(%rip),%rdi
call   1050 <perror@plt>
jmp    115e <main+0x2e>

LLVM IR (-O0):
@.str = [17 x i8] c"enter file name\0A\00"
@.str.1 = [2 x i8] c"r\00"
@.str.2 = [10 x i8] c"open file\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 ne i32 %7, 2
br i1 %8, label %9, label %11
9: ; preds = %2
%10 = call i32 @printf(i8* getelementptr inbounds ([17 x i8], [17 x i8]* @.str, i64 0, i64 0))
store i32 1, i32* %3
br label %21
11: ; preds = %2
%12 = load i8**, i8*** %5
%13 = getelementptr inbounds i8*, i8** %12, i64 1
%14 = load i8*, i8** %13
%15 = call i32* @fopen(i8* %14, i8* getelementptr inbounds ([2 x i8], [2 x i8]* @.str.1, i64 0, i64 0))
store i32* %15, i32** %6
%16 = load i32*, i32** %6
%17 = icmp eq i32* %16, null
br i1 %17, label %18, label %20
18: ; preds = %11
%19 = call i32 @perror(i8* getelementptr inbounds ([10 x i8], [10 x i8]* @.str.2, i64 0, i64 0))
store i32 1, i32* %3
br label %21
20: ; preds = %11
store i32 0, i32* %3
br label %21
21: ; preds = %20, %18, %9
%22 = load i32, i32* %3
ret i32 %22
}

LLVM IR (-O2):
@.str.1 = [2 x i8] c"r\00"
@.str.2 = [10 x i8] c"open file\00"
@str = [16 x i8] c"enter file name\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 ([16 x i8], [16 x i8]* @str, i64 0, i64 0))
br label %13
6: ; preds = %2
%7 = getelementptr inbounds i8*, i8** %1, i64 1
%8 = load i8*, i8** %7
%9 = tail call i32* @fopen(i8* %8, i8* getelementptr inbounds ([2 x i8], [2 x i8]* @.str.1, i64 0, i64 0))
%10 = icmp eq i32* %9, null
br i1 %10, label %11, label %13
11: ; preds = %6
%12 = tail call i32 @perror(i8* getelementptr inbounds ([10 x i8], [10 x i8]* @.str.2, i64 0, i64 0))
br label %13
13: ; preds = %11, %6, %4
%14 = phi i32 [ 1, %4 ], [ 1, %11 ], [ 0, %6 ]
ret i32 %14
}