#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 EXIT_SUCCESS;
int /*<<< orphan*/ fclose(int /*<<< orphan*/ *);
int /*<<< orphan*/ *fopen(char *, char *);
int /*<<< orphan*/ fprintf(int /*<<< orphan*/ *, char *, unsigned int);
int export_gpio_pin(unsigned int pin) {
  FILE *export_file = fopen("/sys/class/gpio/export", "a");
  if (export_file == NULL) {
    return 100;
  }
  fprintf(export_file, "%d", pin);
  fclose(export_file);
  return EXIT_SUCCESS;
}


x86 assembly (clang, -O0):
<export_gpio_pin>:
push   %rbp
mov    %rsp,%rbp
sub    $0x10,%rsp
mov    %edi,-0x8(%rbp)
lea    0xebe(%rip),%rdi
lea    0xece(%rip),%rsi
call   1050 <fopen@plt>
mov    %rax,-0x10(%rbp)
cmpq   $0x0,-0x10(%rbp)
jne    1169 <export_gpio_pin+0x39>
movl   $0x64,-0x4(%rbp)
jmp    1191 <export_gpio_pin+0x61>
mov    -0x10(%rbp),%rdi
mov    -0x8(%rbp),%edx
lea    0xea2(%rip),%rsi
call   1040 <fprintf@plt>
mov    -0x10(%rbp),%rdi
call   1030 <fclose@plt>
mov    0x2e54(%rip),%rax
mov    (%rax),%eax
mov    %eax,-0x4(%rbp)
mov    -0x4(%rbp),%eax
add    $0x10,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<export_gpio_pin>:
push   %rbp
push   %rbx
push   %rax
mov    %edi,%ebp
lea    0xec4(%rip),%rdi
lea    0xed4(%rip),%rsi
call   1050 <fopen@plt>
test   %rax,%rax
je     1174 <export_gpio_pin+0x44>
mov    %rax,%rbx
lea    0xec2(%rip),%rsi
mov    %rax,%rdi
mov    %ebp,%edx
call   1040 <fprintf@plt>
mov    %rbx,%rdi
call   1030 <fclose@plt>
mov    0x2e70(%rip),%rax
mov    (%rax),%eax
jmp    1179 <export_gpio_pin+0x49>
mov    $0x64,%eax
add    $0x8,%rsp
pop    %rbx
pop    %rbp
ret

LLVM IR (-O0):
@.str = [23 x i8] c"/sys/class/gpio/export\00"
@.str.1 = [2 x i8] c"a\00"
@.str.2 = [3 x i8] c"%d\00"
@EXIT_SUCCESS = global i32 0
define i32 @export_gpio_pin(i32 %0) {
%2 = alloca i32
%3 = alloca i32
%4 = alloca i32*
store i32 %0, i32* %3
%5 = call i32* @fopen(i8* getelementptr inbounds ([23 x i8], [23 x i8]* @.str, i64 0, i64 0), i8* getelementptr inbounds ([2 x i8], [2 x i8]* @.str.1, i64 0, i64 0))
store i32* %5, i32** %4
%6 = load i32*, i32** %4
%7 = icmp eq i32* %6, null
br i1 %7, label %8, label %9
8: ; preds = %1
store i32 100, i32* %2
br label %16
9: ; preds = %1
%10 = load i32*, i32** %4
%11 = load i32, i32* %3
%12 = call i32 @fprintf(i32* %10, i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str.2, i64 0, i64 0), i32 %11)
%13 = load i32*, i32** %4
%14 = call i32 @fclose(i32* %13)
%15 = load i32, i32* @EXIT_SUCCESS
store i32 %15, i32* %2
br label %16
16: ; preds = %9, %8
%17 = load i32, i32* %2
ret i32 %17
}

LLVM IR (-O2):
@.str = [23 x i8] c"/sys/class/gpio/export\00"
@.str.1 = [2 x i8] c"a\00"
@.str.2 = [3 x i8] c"%d\00"
@EXIT_SUCCESS = global i32 0
define i32 @export_gpio_pin(i32 %0) {
%2 = tail call i32* @fopen(i8* getelementptr inbounds ([23 x i8], [23 x i8]* @.str, i64 0, i64 0), i8* getelementptr inbounds ([2 x i8], [2 x i8]* @.str.1, i64 0, i64 0))
%3 = icmp eq i32* %2, null
br i1 %3, label %8, label %4
4: ; preds = %1
%5 = tail call i32 @fprintf(i32* %2, i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str.2, i64 0, i64 0), i32 %0)
%6 = tail call i32 @fclose(i32* %2)
%7 = load i32, i32* @EXIT_SUCCESS
br label %8
8: ; preds = %1, %4
%9 = phi i32 [ %7, %4 ], [ 100, %1 ]
ret i32 %9
}