#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*/ fprintf(int /*<<< orphan*/, char *, char *);
int /*<<< orphan*/ stderr;
int /*<<< orphan*/ *stdin;
int main(int argc, char **argv) {
  FILE *f;
  if (argc == 2) {
    f = fopen(argv[1], "r");
    if (f == NULL) {
      fprintf(stderr, "could not open %s\n", argv[1]);
      return 1;
    }
  } else
    f = stdin;
}


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)
jne    1191 <main+0x71>
mov    -0x10(%rbp),%rax
mov    0x8(%rax),%rdi
lea    0xeb1(%rip),%rsi
call   1040 <fopen@plt>
mov    %rax,-0x18(%rbp)
cmpq   $0x0,-0x18(%rbp)
jne    118c <main+0x6c>
mov    0x2e6e(%rip),%rax
mov    (%rax),%edi
mov    -0x10(%rbp),%rax
mov    0x8(%rax),%rdx
lea    0xe87(%rip),%rsi
call   1030 <fprintf@plt>
movl   $0x1,-0x4(%rbp)
jmp    119f <main+0x7f>
jmp    119f <main+0x7f>
mov    0x2e50(%rip),%rax
mov    (%rax),%rax
mov    %rax,-0x18(%rbp)
mov    -0x4(%rbp),%eax
add    $0x20,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<main>:
push   %r14
push   %rbx
push   %rax
xor    %ebx,%ebx
cmp    $0x2,%edi
jne    1161 <main+0x41>
mov    %rsi,%r14
mov    0x8(%rsi),%rdi
lea    0xec7(%rip),%rsi
call   1040 <fopen@plt>
test   %rax,%rax
jne    1161 <main+0x41>
mov    0x2e96(%rip),%rax
mov    (%rax),%edi
mov    0x8(%r14),%rdx
lea    0xeab(%rip),%rsi
call   1030 <fprintf@plt>
mov    $0x1,%ebx
mov    %ebx,%eax
add    $0x8,%rsp
pop    %rbx
pop    %r14
ret

LLVM IR (-O0):
@.str = [2 x i8] c"r\00"
@stderr = global i32 0
@.str.1 = [19 x i8] c"could not open %s\0A\00"
@stdin = global i32* null
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 eq i32 %7, 2
br i1 %8, label %9, label %23
9: ; preds = %2
%10 = load i8**, i8*** %5
%11 = getelementptr inbounds i8*, i8** %10, i64 1
%12 = load i8*, i8** %11
%13 = call i32* @fopen(i8* %12, i8* getelementptr inbounds ([2 x i8], [2 x i8]* @.str, i64 0, i64 0))
store i32* %13, i32** %6
%14 = load i32*, i32** %6
%15 = icmp eq i32* %14, null
br i1 %15, label %16, label %22
16: ; preds = %9
%17 = load i32, i32* @stderr
%18 = load i8**, i8*** %5
%19 = getelementptr inbounds i8*, i8** %18, i64 1
%20 = load i8*, i8** %19
%21 = call i32 @fprintf(i32 %17, i8* getelementptr inbounds ([19 x i8], [19 x i8]* @.str.1, i64 0, i64 0), i8* %20)
store i32 1, i32* %3
br label %25
22: ; preds = %9
br label %25
23: ; preds = %2
%24 = load i32*, i32** @stdin
store i32* %24, i32** %6
br label %25
25: ; preds = %16, %23, %22
%26 = load i32, i32* %3
ret i32 %26
}

LLVM IR (-O2):
@.str = [2 x i8] c"r\00"
@stderr = global i32 0
@.str.1 = [19 x i8] c"could not open %s\0A\00"
@stdin = global i32* null
define i32 @main(i32 %0, i8** nocapture %1) {
%3 = icmp eq i32 %0, 2
br i1 %3, label %4, label %13
4: ; preds = %2
%5 = getelementptr inbounds i8*, i8** %1, i64 1
%6 = load i8*, i8** %5
%7 = tail call i32* @fopen(i8* %6, i8* getelementptr inbounds ([2 x i8], [2 x i8]* @.str, i64 0, i64 0))
%8 = icmp eq i32* %7, null
br i1 %8, label %9, label %13
9: ; preds = %4
%10 = load i32, i32* @stderr
%11 = load i8*, i8** %5
%12 = tail call i32 @fprintf(i32 %10, i8* getelementptr inbounds ([19 x i8], [19 x i8]* @.str.1, i64 0, i64 0), i8* %11)
br label %13
13: ; preds = %4, %2, %9
%14 = phi i32 [ 1, %9 ], [ 0, %2 ], [ 0, %4 ]
ret i32 %14
}