#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*/ exit(int);
int /*<<< orphan*/ *fopen(char *, char *);
int /*<<< orphan*/ fprintf(int /*<<< orphan*/, char *, char *);
int /*<<< orphan*/ perror(char *);
int /*<<< orphan*/ stderr;
FILE *openWrite(char *filename) {
  FILE *fp;
  fp = fopen(filename, "w");
  if (!fp) {
    fprintf(stderr, "%s could not be open for writing\n", filename);
    perror("weighbor::io::openWrite");
    exit(1);
  }
  return (fp);
}


x86 assembly (clang, -O0):
<openWrite>:
push   %rbp
mov    %rsp,%rbp
sub    $0x10,%rsp
mov    %rdi,-0x8(%rbp)
mov    -0x8(%rbp),%rdi
lea    0xea9(%rip),%rsi
call   1040 <fopen@plt>
mov    %rax,-0x10(%rbp)
cmpq   $0x0,-0x10(%rbp)
jne    119a <openWrite+0x5a>
mov    0x2e6e(%rip),%rax
mov    (%rax),%edi
mov    -0x8(%rbp),%rdx
lea    0xe83(%rip),%rsi
call   1030 <fprintf@plt>
lea    0xe99(%rip),%rdi
call   1050 <perror@plt>
mov    $0x1,%edi
call   1060 <exit@plt>
mov    -0x10(%rbp),%rax
add    $0x10,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<openWrite>:
push   %rbx
mov    %rdi,%rbx
lea    0xeb5(%rip),%rsi
call   1040 <fopen@plt>
test   %rax,%rax
je     1157 <openWrite+0x17>
pop    %rbx
ret
mov    0x2e82(%rip),%rax
mov    (%rax),%edi
lea    0xe9b(%rip),%rsi
mov    %rbx,%rdx
call   1030 <fprintf@plt>
lea    0xeae(%rip),%rdi
call   1050 <perror@plt>
mov    $0x1,%edi
call   1060 <exit@plt>

LLVM IR (-O0):
@.str = [2 x i8] c"w\00"
@stderr = global i32 0
@.str.1 = [34 x i8] c"%s could not be open for writing\0A\00"
@.str.2 = [24 x i8] c"weighbor::io::openWrite\00"
define i32* @openWrite(i8* %0) {
%2 = alloca i8*
%3 = alloca i32*
store i8* %0, i8** %2
%4 = load i8*, i8** %2
%5 = call i32* @fopen(i8* %4, i8* getelementptr inbounds ([2 x i8], [2 x i8]* @.str, i64 0, i64 0))
store i32* %5, i32** %3
%6 = load i32*, i32** %3
%7 = icmp ne i32* %6, null
br i1 %7, label %14, label %8
8: ; preds = %1
%9 = load i32, i32* @stderr
%10 = load i8*, i8** %2
%11 = call i32 @fprintf(i32 %9, i8* getelementptr inbounds ([34 x i8], [34 x i8]* @.str.1, i64 0, i64 0), i8* %10)
%12 = call i32 @perror(i8* getelementptr inbounds ([24 x i8], [24 x i8]* @.str.2, i64 0, i64 0))
%13 = call i32 @exit(i32 1)
unreachable
14: ; preds = %1
%15 = load i32*, i32** %3
ret i32* %15
}

LLVM IR (-O2):
@.str = [2 x i8] c"w\00"
@stderr = global i32 0
@.str.1 = [34 x i8] c"%s could not be open for writing\0A\00"
@.str.2 = [24 x i8] c"weighbor::io::openWrite\00"
define noalias i32* @openWrite(i8* %0) {
%2 = tail call i32* @fopen(i8* %0, i8* getelementptr inbounds ([2 x i8], [2 x i8]* @.str, i64 0, i64 0))
%3 = icmp eq i32* %2, null
br i1 %3, label %4, label %9
4: ; preds = %1
%5 = load i32, i32* @stderr
%6 = tail call i32 @fprintf(i32 %5, i8* getelementptr inbounds ([34 x i8], [34 x i8]* @.str.1, i64 0, i64 0), i8* %0)
%7 = tail call i32 @perror(i8* getelementptr inbounds ([24 x i8], [24 x i8]* @.str.2, i64 0, i64 0))
%8 = tail call i32 @exit(i32 1)
unreachable
9: ; preds = %1
ret i32* %2
}