#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(void) {
  int fd;
  fd = open("test.txt", O_RDONLY);
  if (fd == -1) {
    printf("open error!\n");
    return -1;
  }
  printf("fd = %d\n", fd);
  close(fd);
  return 0;
}


x86 assembly (clang, -O0):
<main>:
push   %rbp
mov    %rsp,%rbp
sub    $0x10,%rsp
movl   $0x0,-0x4(%rbp)
mov    0x2ea2(%rip),%rax
mov    (%rax),%esi
lea    0xeb1(%rip),%rdi
call   1050 <open@plt>
mov    %eax,-0x8(%rbp)
cmpl   $0xffffffff,-0x8(%rbp)
jne    117b <main+0x4b>
lea    0xea1(%rip),%rdi
mov    $0x0,%al
call   1030 <printf@plt>
movl   $0xffffffff,-0x4(%rbp)
jmp    119b <main+0x6b>
mov    -0x8(%rbp),%esi
lea    0xe91(%rip),%rdi
mov    $0x0,%al
call   1030 <printf@plt>
mov    -0x8(%rbp),%edi
call   1040 <close@plt>
movl   $0x0,-0x4(%rbp)
mov    -0x4(%rbp),%eax
add    $0x10,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<main>:
push   %rbp
push   %rbx
push   %rax
mov    0x2e9e(%rip),%rax
mov    (%rax),%esi
lea    0xead(%rip),%rdi
call   1060 <open@plt>
cmp    $0xffffffff,%eax
je     117a <main+0x3a>
mov    %eax,%ebp
lea    0xea3(%rip),%rdi
xor    %ebx,%ebx
mov    %eax,%esi
xor    %eax,%eax
call   1040 <printf@plt>
mov    %ebp,%edi
call   1050 <close@plt>
jmp    118b <main+0x4b>
lea    0xe91(%rip),%rdi
call   1030 <puts@plt>
mov    $0xffffffff,%ebx
mov    %ebx,%eax
add    $0x8,%rsp
pop    %rbx
pop    %rbp
ret

LLVM IR (-O0):
@.str = [9 x i8] c"test.txt\00"
@O_RDONLY = global i32 0
@.str.1 = [13 x i8] c"open error!\0A\00"
@.str.2 = [9 x i8] c"fd = %d\0A\00"
define i32 @main() {
%1 = alloca i32
%2 = alloca i32
store i32 0, i32* %1
%3 = load i32, i32* @O_RDONLY
%4 = call i32 @open(i8* getelementptr inbounds ([9 x i8], [9 x i8]* @.str, i64 0, i64 0), i32 %3)
store i32 %4, i32* %2
%5 = load i32, i32* %2
%6 = icmp eq i32 %5, -1
br i1 %6, label %7, label %9
7: ; preds = %0
%8 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([13 x i8], [13 x i8]* @.str.1, i64 0, i64 0))
store i32 -1, i32* %1
br label %14
9: ; preds = %0
%10 = load i32, i32* %2
%11 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([9 x i8], [9 x i8]* @.str.2, i64 0, i64 0), i32 %10)
%12 = load i32, i32* %2
%13 = call i32 @close(i32 %12)
store i32 0, i32* %1
br label %14
14: ; preds = %9, %7
%15 = load i32, i32* %1
ret i32 %15
}

LLVM IR (-O2):
@.str = [9 x i8] c"test.txt\00"
@O_RDONLY = global i32 0
@.str.2 = [9 x i8] c"fd = %d\0A\00"
@str = [12 x i8] c"open error!\00"
define i32 @main() {
%1 = load i32, i32* @O_RDONLY
%2 = tail call i32 @open(i8* getelementptr inbounds ([9 x i8], [9 x i8]* @.str, i64 0, i64 0), i32 %1)
%3 = icmp eq i32 %2, -1
br i1 %3, label %4, label %6
4: ; preds = %0
%5 = tail call i32 @puts(i8* dereferenceable(1) getelementptr inbounds ([12 x i8], [12 x i8]* @str, i64 0, i64 0))
br label %9
6: ; preds = %0
%7 = tail call i32 (i8*, ...) @printf(i8* dereferenceable(1) getelementptr inbounds ([9 x i8], [9 x i8]* @.str.2, i64 0, i64 0), i32 %2)
%8 = tail call i32 @close(i32 %2)
br label %9
9: ; preds = %6, %4
%10 = phi i32 [ -1, %4 ], [ 0, %6 ]
ret i32 %10
}