#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*/ Display;

/* Variables and functions */
int /*<<< orphan*/ XCloseDisplay(int /*<<< orphan*/ *);
int /*<<< orphan*/ *XOpenDisplay(char *);
int /*<<< orphan*/ exit(int);
int /*<<< orphan*/ fprintf(int /*<<< orphan*/, char *, char *);
char *getenv(char *);
int /*<<< orphan*/ stderr;
int main(void) {
  char *display_name;
  Display *d;
  display_name = getenv("DISPLAY");
  d = XOpenDisplay(display_name);
  if (d == NULL) {
    fprintf(stderr, "Unable to open Display: %s\n", display_name);
    exit(1);
  }
  XCloseDisplay(d);
  return 0;
}


x86 assembly (clang, -O0):
<main>:
push   %rbp
mov    %rsp,%rbp
sub    $0x20,%rsp
movl   $0x0,-0x4(%rbp)
lea    0xe9a(%rip),%rdi
call   1030 <getenv@plt>
mov    %rax,-0x10(%rbp)
mov    -0x10(%rbp),%rdi
call   1040 <XOpenDisplay@plt>
mov    %rax,-0x18(%rbp)
cmpq   $0x0,-0x18(%rbp)
jne    11aa <main+0x5a>
mov    0x2e52(%rip),%rax
mov    (%rax),%edi
mov    -0x10(%rbp),%rdx
lea    0xe6d(%rip),%rsi
call   1050 <fprintf@plt>
mov    $0x1,%edi
call   1060 <exit@plt>
mov    -0x18(%rbp),%rdi
call   1070 <XCloseDisplay@plt>
xor    %eax,%eax
add    $0x20,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<main>:
push   %rbx
lea    0xea8(%rip),%rdi
call   1030 <getenv@plt>
mov    %rax,%rbx
mov    %rax,%rdi
call   1040 <XOpenDisplay@plt>
test   %rax,%rax
je     1179 <main+0x29>
mov    %rax,%rdi
call   1070 <XCloseDisplay@plt>
xor    %eax,%eax
pop    %rbx
ret
mov    0x2e60(%rip),%rax
mov    (%rax),%edi
lea    0xe7f(%rip),%rsi
mov    %rbx,%rdx
call   1050 <fprintf@plt>
mov    $0x1,%edi
call   1060 <exit@plt>

LLVM IR (-O0):
@.str = [8 x i8] c"DISPLAY\00"
@stderr = global i32 0
@.str.1 = [28 x i8] c"Unable to open Display: %s\0A\00"
define i32 @main() {
%1 = alloca i32
%2 = alloca i8*
%3 = alloca i32*
store i32 0, i32* %1
%4 = call i8* @getenv(i8* getelementptr inbounds ([8 x i8], [8 x i8]* @.str, i64 0, i64 0))
store i8* %4, i8** %2
%5 = load i8*, i8** %2
%6 = call i32* @XOpenDisplay(i8* %5)
store i32* %6, i32** %3
%7 = load i32*, i32** %3
%8 = icmp eq i32* %7, null
br i1 %8, label %9, label %14
9: ; preds = %0
%10 = load i32, i32* @stderr
%11 = load i8*, i8** %2
%12 = call i32 @fprintf(i32 %10, i8* getelementptr inbounds ([28 x i8], [28 x i8]* @.str.1, i64 0, i64 0), i8* %11)
%13 = call i32 @exit(i32 1)
unreachable
14: ; preds = %0
%15 = load i32*, i32** %3
%16 = call i32 @XCloseDisplay(i32* %15)
ret i32 0
}

LLVM IR (-O2):
@.str = [8 x i8] c"DISPLAY\00"
@stderr = global i32 0
@.str.1 = [28 x i8] c"Unable to open Display: %s\0A\00"
define i32 @main() {
%1 = tail call i8* @getenv(i8* getelementptr inbounds ([8 x i8], [8 x i8]* @.str, i64 0, i64 0))
%2 = tail call i32* @XOpenDisplay(i8* %1)
%3 = icmp eq i32* %2, null
br i1 %3, label %4, label %8
4: ; preds = %0
%5 = load i32, i32* @stderr
%6 = tail call i32 @fprintf(i32 %5, i8* getelementptr inbounds ([28 x i8], [28 x i8]* @.str.1, i64 0, i64 0), i8* %1)
%7 = tail call i32 @exit(i32 1)
unreachable
8: ; preds = %0
%9 = tail call i32 @XCloseDisplay(i32* %2)
ret i32 0
}