#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_RDWR;
int open(char *, int /*<<< orphan*/);
int /*<<< orphan*/ printf(char *, ...);
scalar_t__ strcmp(char *, char *);
int /*<<< orphan*/ write(int, int *, int);
int main(int argc, char **argv) {
  int fd;
  int val = 1;
  fd = open("/dev/xyz", O_RDWR);
  if (fd < 0) {
    printf("can't open!\n");
  }
  if (argc != 2) {
    printf("Usage :\n");
    printf("%s <on|off>\n", argv[0]);
    return 0;
  }
  if (strcmp(argv[1], "on") == 0) {
    val = 1;
  } else {
    val = 0;
  }
  write(fd, &val, 4);
  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)
movl   $0x1,-0x18(%rbp)
mov    0x2e84(%rip),%rax
mov    (%rax),%esi
lea    0xe93(%rip),%rdi
call   1060 <open@plt>
mov    %eax,-0x14(%rbp)
cmpl   $0x0,-0x14(%rbp)
jge    118d <main+0x4d>
lea    0xe83(%rip),%rdi
mov    $0x0,%al
call   1040 <printf@plt>
cmpl   $0x2,-0x8(%rbp)
je     11c6 <main+0x86>
lea    0xe78(%rip),%rdi
mov    $0x0,%al
call   1040 <printf@plt>
mov    -0x10(%rbp),%rax
mov    (%rax),%rsi
lea    0xe6c(%rip),%rdi
mov    $0x0,%al
call   1040 <printf@plt>
movl   $0x0,-0x4(%rbp)
jmp    120f <main+0xcf>
mov    -0x10(%rbp),%rax
mov    0x8(%rax),%rdi
lea    0xe57(%rip),%rsi
call   1050 <strcmp@plt>
cmp    $0x0,%rax
jne    11f0 <main+0xb0>
movl   $0x1,-0x18(%rbp)
jmp    11f7 <main+0xb7>
movl   $0x0,-0x18(%rbp)
mov    -0x14(%rbp),%edi
lea    -0x18(%rbp),%rsi
mov    $0x4,%edx
call   1030 <write@plt>
movl   $0x0,-0x4(%rbp)
mov    -0x4(%rbp),%eax
add    $0x20,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<main>:
push   %rbp
push   %r14
push   %rbx
sub    $0x10,%rsp
mov    %rsi,%r14
mov    %edi,%ebp
mov    0x2e84(%rip),%rax
mov    (%rax),%esi
lea    0xe93(%rip),%rdi
call   1070 <open@plt>
mov    %eax,%ebx
test   %eax,%eax
js     11ac <main+0x5c>
cmp    $0x2,%ebp
jne    11bd <main+0x6d>
mov    0x8(%r14),%rdi
lea    0xe8e(%rip),%rsi
call   1060 <strcmp@plt>
xor    %ecx,%ecx
test   %rax,%rax
sete   %cl
mov    %ecx,0xc(%rsp)
lea    0xc(%rsp),%rsi
mov    %ebx,%edi
mov    $0x4,%edx
call   1040 <write@plt>
jmp    11da <main+0x8a>
lea    0xe6e(%rip),%rdi
call   1030 <puts@plt>
cmp    $0x2,%ebp
je     117d <main+0x2d>
lea    0xe55(%rip),%rdi
call   1030 <puts@plt>
mov    (%r14),%rsi
lea    0xe36(%rip),%rdi
xor    %eax,%eax
call   1050 <printf@plt>
xor    %eax,%eax
add    $0x10,%rsp
pop    %rbx
pop    %r14
pop    %rbp
ret

LLVM IR (-O0):
@.str = [9 x i8] c"/dev/xyz\00"
@O_RDWR = global i32 0
@.str.1 = [13 x i8] c"can't open!\0A\00"
@.str.2 = [9 x i8] c"Usage :\0A\00"
@.str.3 = [13 x i8] c"%s <on|off>\0A\00"
@.str.4 = [3 x i8] c"on\00"
define i32 @main(i32 %0, i8** %1) {
%3 = alloca i32
%4 = alloca i32
%5 = alloca i8**
%6 = alloca i32
%7 = alloca i32
store i32 0, i32* %3
store i32 %0, i32* %4
store i8** %1, i8*** %5
store i32 1, i32* %7
%8 = load i32, i32* @O_RDWR
%9 = call i32 @open(i8* getelementptr inbounds ([9 x i8], [9 x i8]* @.str, i64 0, i64 0), i32 %8)
store i32 %9, i32* %6
%10 = load i32, i32* %6
%11 = icmp slt i32 %10, 0
br i1 %11, label %12, label %14
12: ; preds = %2
%13 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([13 x i8], [13 x i8]* @.str.1, i64 0, i64 0))
br label %14
14: ; preds = %12, %2
%15 = load i32, i32* %4
%16 = icmp ne i32 %15, 2
br i1 %16, label %17, label %23
17: ; preds = %14
%18 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([9 x i8], [9 x i8]* @.str.2, i64 0, i64 0))
%19 = load i8**, i8*** %5
%20 = getelementptr inbounds i8*, i8** %19, i64 0
%21 = load i8*, i8** %20
%22 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([13 x i8], [13 x i8]* @.str.3, i64 0, i64 0), i8* %21)
store i32 0, i32* %3
br label %34
23: ; preds = %14
%24 = load i8**, i8*** %5
%25 = getelementptr inbounds i8*, i8** %24, i64 1
%26 = load i8*, i8** %25
%27 = call i64 @strcmp(i8* %26, i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str.4, i64 0, i64 0))
%28 = icmp eq i64 %27, 0
br i1 %28, label %29, label %30
29: ; preds = %23
store i32 1, i32* %7
br label %31
30: ; preds = %23
store i32 0, i32* %7
br label %31
31: ; preds = %30, %29
%32 = load i32, i32* %6
%33 = call i32 @write(i32 %32, i32* %7, i32 4)
store i32 0, i32* %3
br label %34
34: ; preds = %31, %17
%35 = load i32, i32* %3
ret i32 %35
}

LLVM IR (-O2):
@.str = [9 x i8] c"/dev/xyz\00"
@O_RDWR = global i32 0
@.str.3 = [13 x i8] c"%s <on|off>\0A\00"
@.str.4 = [3 x i8] c"on\00"
@str = [8 x i8] c"Usage :\00"
@str.5 = [12 x i8] c"can't open!\00"
define i32 @main(i32 %0, i8** nocapture %1) {
%3 = alloca i32
%4 = bitcast i32* %3 to i8*
%5 = load i32, i32* @O_RDWR
%6 = tail call i32 @open(i8* getelementptr inbounds ([9 x i8], [9 x i8]* @.str, i64 0, i64 0), i32 %5)
%7 = icmp slt i32 %6, 0
br i1 %7, label %8, label %10
8: ; preds = %2
%9 = tail call i32 @puts(i8* dereferenceable(1) getelementptr inbounds ([12 x i8], [12 x i8]* @str.5, i64 0, i64 0))
br label %10
10: ; preds = %8, %2
%11 = icmp eq i32 %0, 2
br i1 %11, label %16, label %12
12: ; preds = %10
%13 = tail call i32 @puts(i8* dereferenceable(1) getelementptr inbounds ([8 x i8], [8 x i8]* @str, i64 0, i64 0))
%14 = load i8*, i8** %1
%15 = tail call i32 (i8*, ...) @printf(i8* dereferenceable(1) getelementptr inbounds ([13 x i8], [13 x i8]* @.str.3, i64 0, i64 0), i8* %14)
br label %23
16: ; preds = %10
%17 = getelementptr inbounds i8*, i8** %1, i64 1
%18 = load i8*, i8** %17
%19 = tail call i64 @strcmp(i8* %18, i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str.4, i64 0, i64 0))
%20 = icmp eq i64 %19, 0
%21 = zext i1 %20 to i32
store i32 %21, i32* %3
%22 = call i32 @write(i32 %6, i32* %3, i32 4)
br label %23
23: ; preds = %16, %12
ret i32 0
}