#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*/ buf;

/* Variables and functions */
int O_NONBLOCK;
int O_RDONLY;
int open(char *, int);
int /*<<< orphan*/ perror(char *);
int /*<<< orphan*/ snprintf(char *, int, char *, unsigned int);
int gpio_fd_open(unsigned int gpio) {
  int fd;
  char buf[64];
  snprintf(buf, sizeof(buf),
           "/sys/class/gpio"
           "/gpio%d/value",
           gpio);
  fd = open(buf, O_RDONLY | O_NONBLOCK);
  if (fd < 0) {
    perror("gpio/fd_open");
  }
  return fd;
}


x86 assembly (clang, -O0):
<gpio_fd_open>:
push   %rbp
mov    %rsp,%rbp
sub    $0x50,%rsp
mov    %edi,-0x4(%rbp)
lea    -0x50(%rbp),%rdi
mov    -0x4(%rbp),%ecx
mov    $0x40,%esi
lea    0xeb2(%rip),%rdx
call   1030 <snprintf@plt>
lea    -0x50(%rbp),%rdi
mov    0x2e82(%rip),%rax
mov    (%rax),%esi
mov    0x2e81(%rip),%rax
or     (%rax),%esi
call   1040 <open@plt>
mov    %eax,-0x8(%rbp)
cmpl   $0x0,-0x8(%rbp)
jge    1187 <gpio_fd_open+0x57>
lea    0xe9b(%rip),%rdi
call   1050 <perror@plt>
mov    -0x8(%rbp),%eax
add    $0x50,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<gpio_fd_open>:
push   %rbx
sub    $0x40,%rsp
mov    %edi,%ecx
lea    0xec2(%rip),%rdx
mov    %rsp,%rbx
mov    %rbx,%rdi
mov    $0x40,%esi
call   1030 <snprintf@plt>
mov    0x2e8b(%rip),%rax
mov    0x2e8c(%rip),%rcx
mov    (%rcx),%esi
or     (%rax),%esi
mov    %rbx,%rdi
call   1040 <open@plt>
mov    %eax,%ebx
test   %eax,%eax
js     1176 <gpio_fd_open+0x46>
mov    %ebx,%eax
add    $0x40,%rsp
pop    %rbx
ret
lea    0xea0(%rip),%rdi
call   1050 <perror@plt>
jmp    116e <gpio_fd_open+0x3e>

LLVM IR (-O0):
@.str = [29 x i8] c"/sys/class/gpio/gpio%d/value\00"
@O_RDONLY = global i32 0
@O_NONBLOCK = global i32 0
@.str.1 = [13 x i8] c"gpio/fd_open\00"
define i32 @gpio_fd_open(i32 %0) {
%2 = alloca i32
%3 = alloca i32
%4 = alloca [64 x i8]
store i32 %0, i32* %2
%5 = getelementptr inbounds [64 x i8], [64 x i8]* %4, i64 0, i64 0
%6 = load i32, i32* %2
%7 = call i32 @snprintf(i8* %5, i32 64, i8* getelementptr inbounds ([29 x i8], [29 x i8]* @.str, i64 0, i64 0), i32 %6)
%8 = getelementptr inbounds [64 x i8], [64 x i8]* %4, i64 0, i64 0
%9 = load i32, i32* @O_RDONLY
%10 = load i32, i32* @O_NONBLOCK
%11 = or i32 %9, %10
%12 = call i32 @open(i8* %8, i32 %11)
store i32 %12, i32* %3
%13 = load i32, i32* %3
%14 = icmp slt i32 %13, 0
br i1 %14, label %15, label %17
15: ; preds = %1
%16 = call i32 @perror(i8* getelementptr inbounds ([13 x i8], [13 x i8]* @.str.1, i64 0, i64 0))
br label %17
17: ; preds = %15, %1
%18 = load i32, i32* %3
ret i32 %18
}

LLVM IR (-O2):
@.str = [29 x i8] c"/sys/class/gpio/gpio%d/value\00"
@O_RDONLY = global i32 0
@O_NONBLOCK = global i32 0
@.str.1 = [13 x i8] c"gpio/fd_open\00"
define i32 @gpio_fd_open(i32 %0) {
%2 = alloca [64 x i8]
%3 = getelementptr inbounds [64 x i8], [64 x i8]* %2, i64 0, i64 0
%4 = call i32 @snprintf(i8* %3, i32 64, i8* getelementptr inbounds ([29 x i8], [29 x i8]* @.str, i64 0, i64 0), i32 %0)
%5 = load i32, i32* @O_RDONLY
%6 = load i32, i32* @O_NONBLOCK
%7 = or i32 %6, %5
%8 = call i32 @open(i8* %3, i32 %7)
%9 = icmp slt i32 %8, 0
br i1 %9, label %10, label %12
10: ; preds = %1
%11 = call i32 @perror(i8* getelementptr inbounds ([13 x i8], [13 x i8]* @.str.1, i64 0, i64 0))
br label %12
12: ; preds = %10, %1
ret i32 %8
}