#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_RDONLY;
int /*<<< orphan*/ close(int);
int open(char *, int /*<<< orphan*/);
int /*<<< orphan*/ printf(char *, ...);
int main(int argc, char *argv[]) {
  if (argc != 2) {
    printf("arg is wrong\n");
    return -1;
  }
  int fd = open(argv[1], O_RDONLY);
  if (fd < 0) {
    printf("can't open %s\n", argv[1]);
    return -1;
  }
  close(fd);
  printf("finished poking, use dmesg to check the result\n");
  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     116a <main+0x3a>
lea    0xea9(%rip),%rdi
mov    $0x0,%al
call   1030 <printf@plt>
movl   $0xffffffff,-0x4(%rbp)
jmp    11cc <main+0x9c>
mov    -0x10(%rbp),%rax
mov    0x8(%rax),%rdi
mov    0x2e6f(%rip),%rax
mov    (%rax),%esi
call   1050 <open@plt>
mov    %eax,-0x14(%rbp)
cmpl   $0x0,-0x14(%rbp)
jge    11af <main+0x7f>
mov    -0x10(%rbp),%rax
mov    0x8(%rax),%rsi
lea    0xe72(%rip),%rdi
mov    $0x0,%al
call   1030 <printf@plt>
movl   $0xffffffff,-0x4(%rbp)
jmp    11cc <main+0x9c>
mov    -0x14(%rbp),%edi
call   1040 <close@plt>
lea    0xe5f(%rip),%rdi
mov    $0x0,%al
call   1030 <printf@plt>
movl   $0x0,-0x4(%rbp)
mov    -0x4(%rbp),%eax
add    $0x20,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<main>:
push   %rbx
cmp    $0x2,%edi
jne    1176 <main+0x36>
mov    %rsi,%rbx
mov    0x8(%rsi),%rdi
mov    0x2e94(%rip),%rax
mov    (%rax),%esi
call   1060 <open@plt>
test   %eax,%eax
js     1184 <main+0x44>
mov    %eax,%edi
call   1050 <close@plt>
lea    0xea2(%rip),%rdi
call   1030 <puts@plt>
xor    %eax,%eax
pop    %rbx
ret
lea    0xec1(%rip),%rdi
call   1030 <puts@plt>
jmp    1196 <main+0x56>
mov    0x8(%rbx),%rsi
lea    0xe71(%rip),%rdi
xor    %eax,%eax
call   1040 <printf@plt>
mov    $0xffffffff,%eax
pop    %rbx
ret

LLVM IR (-O0):
@.str = [14 x i8] c"arg is wrong\0A\00"
@O_RDONLY = global i32 0
@.str.1 = [15 x i8] c"can't open %s\0A\00"
@.str.2 = [48 x i8] c"finished poking, use dmesg to check the result\0A\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 (i8*, ...) @printf(i8* getelementptr inbounds ([14 x i8], [14 x i8]* @.str, i64 0, i64 0))
store i32 -1, i32* %3
br label %28
11: ; preds = %2
%12 = load i8**, i8*** %5
%13 = getelementptr inbounds i8*, i8** %12, i64 1
%14 = load i8*, i8** %13
%15 = load i32, i32* @O_RDONLY
%16 = call i32 @open(i8* %14, i32 %15)
store i32 %16, i32* %6
%17 = load i32, i32* %6
%18 = icmp slt i32 %17, 0
br i1 %18, label %19, label %24
19: ; preds = %11
%20 = load i8**, i8*** %5
%21 = getelementptr inbounds i8*, i8** %20, i64 1
%22 = load i8*, i8** %21
%23 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([15 x i8], [15 x i8]* @.str.1, i64 0, i64 0), i8* %22)
store i32 -1, i32* %3
br label %28
24: ; preds = %11
%25 = load i32, i32* %6
%26 = call i32 @close(i32 %25)
%27 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([48 x i8], [48 x i8]* @.str.2, i64 0, i64 0))
store i32 0, i32* %3
br label %28
28: ; preds = %24, %19, %9
%29 = load i32, i32* %3
ret i32 %29
}

LLVM IR (-O2):
@O_RDONLY = global i32 0
@.str.1 = [15 x i8] c"can't open %s\0A\00"
@str = [47 x i8] c"finished poking, use dmesg to check the result\00"
@str.3 = [13 x i8] c"arg is wrong\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 ([13 x i8], [13 x i8]* @str.3, i64 0, i64 0))
br label %18
6: ; preds = %2
%7 = getelementptr inbounds i8*, i8** %1, i64 1
%8 = load i8*, i8** %7
%9 = load i32, i32* @O_RDONLY
%10 = tail call i32 @open(i8* %8, i32 %9)
%11 = icmp slt i32 %10, 0
br i1 %11, label %12, label %15
12: ; preds = %6
%13 = load i8*, i8** %7
%14 = tail call i32 (i8*, ...) @printf(i8* dereferenceable(1) getelementptr inbounds ([15 x i8], [15 x i8]* @.str.1, i64 0, i64 0), i8* %13)
br label %18
15: ; preds = %6
%16 = tail call i32 @close(i32 %10)
%17 = tail call i32 @puts(i8* dereferenceable(1) getelementptr inbounds ([47 x i8], [47 x i8]* @str, i64 0, i64 0))
br label %18
18: ; preds = %12, %15, %4
%19 = phi i32 [ -1, %4 ], [ -1, %12 ], [ 0, %15 ]
ret i32 %19
}