#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 /*<<< orphan*/ fclose(int /*<<< orphan*/ *);
int /*<<< orphan*/ *fopen(char *, char *);
int /*<<< orphan*/ fscanf(int /*<<< orphan*/ *, char *, int *);
int /*<<< orphan*/ snprintf(char *, int, char *, int);
int get_pin(int pn) {
  char buffer[256] = {'\0'};
  snprintf(buffer, 255, "/sys/class/gpio/gpio%d/value", pn);
  FILE *inf = fopen(buffer, "rb");
  int rval = 0;
  fscanf(inf, "%d", &rval);
  fclose(inf);
  return rval;
}


x86 assembly (clang, -O0):
<get_pin>:
push   %rbp
mov    %rsp,%rbp
sub    $0x120,%rsp
mov    %edi,-0x4(%rbp)
lea    -0x110(%rbp),%rdi
xor    %esi,%esi
mov    $0x100,%edx
call   1050 <memset@plt>
lea    -0x110(%rbp),%rdi
mov    -0x4(%rbp),%ecx
mov    $0xff,%esi
lea    0xe79(%rip),%rdx
call   1040 <snprintf@plt>
lea    -0x110(%rbp),%rdi
lea    0xe83(%rip),%rsi
call   1070 <fopen@plt>
mov    %rax,-0x118(%rbp)
movl   $0x0,-0x11c(%rbp)
mov    -0x118(%rbp),%rdi
lea    0xe62(%rip),%rsi
lea    -0x11c(%rbp),%rdx
call   1060 <fscanf@plt>
mov    -0x118(%rbp),%rdi
call   1030 <fclose@plt>
mov    -0x11c(%rbp),%eax
add    $0x120,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<get_pin>:
push   %rbx
sub    $0x110,%rsp
mov    %edi,%ecx
xorps  %xmm0,%xmm0
movaps %xmm0,0x100(%rsp)
movaps %xmm0,0xf0(%rsp)
movaps %xmm0,0xe0(%rsp)
movaps %xmm0,0xd0(%rsp)
movaps %xmm0,0xc0(%rsp)
movaps %xmm0,0xb0(%rsp)
movaps %xmm0,0xa0(%rsp)
movaps %xmm0,0x90(%rsp)
movaps %xmm0,0x80(%rsp)
movaps %xmm0,0x70(%rsp)
movaps %xmm0,0x60(%rsp)
movaps %xmm0,0x50(%rsp)
movaps %xmm0,0x40(%rsp)
movaps %xmm0,0x30(%rsp)
movaps %xmm0,0x20(%rsp)
movaps %xmm0,0x10(%rsp)
lea    0xe41(%rip),%rdx
lea    0x10(%rsp),%rbx
mov    %rbx,%rdi
mov    $0xff,%esi
call   1040 <snprintf@plt>
lea    0xe45(%rip),%rsi
mov    %rbx,%rdi
call   1060 <fopen@plt>
mov    %rax,%rbx
movl   $0x0,0xc(%rsp)
lea    0xe2e(%rip),%rsi
lea    0xc(%rsp),%rdx
mov    %rax,%rdi
call   1050 <fscanf@plt>
mov    %rbx,%rdi
call   1030 <fclose@plt>
mov    0xc(%rsp),%eax
add    $0x110,%rsp
pop    %rbx
ret

LLVM IR (-O0):
@.str = [29 x i8] c"/sys/class/gpio/gpio%d/value\00"
@.str.1 = [3 x i8] c"rb\00"
@.str.2 = [3 x i8] c"%d\00"
define i32 @get_pin(i32 %0) {
%2 = alloca i32
%3 = alloca [256 x i8]
%4 = alloca i32*
%5 = alloca i32
store i32 %0, i32* %2
%6 = bitcast [256 x i8]* %3 to i8*
%7 = getelementptr inbounds [256 x i8], [256 x i8]* %3, i64 0, i64 0
%8 = load i32, i32* %2
%9 = call i32 @snprintf(i8* %7, i32 255, i8* getelementptr inbounds ([29 x i8], [29 x i8]* @.str, i64 0, i64 0), i32 %8)
%10 = getelementptr inbounds [256 x i8], [256 x i8]* %3, i64 0, i64 0
%11 = call i32* @fopen(i8* %10, i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str.1, i64 0, i64 0))
store i32* %11, i32** %4
store i32 0, i32* %5
%12 = load i32*, i32** %4
%13 = call i32 @fscanf(i32* %12, i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str.2, i64 0, i64 0), i32* %5)
%14 = load i32*, i32** %4
%15 = call i32 @fclose(i32* %14)
%16 = load i32, i32* %5
ret i32 %16
}

LLVM IR (-O2):
@.str = [29 x i8] c"/sys/class/gpio/gpio%d/value\00"
@.str.1 = [3 x i8] c"rb\00"
@.str.2 = [3 x i8] c"%d\00"
define i32 @get_pin(i32 %0) {
%2 = alloca [256 x i8]
%3 = alloca i32
%4 = getelementptr inbounds [256 x i8], [256 x i8]* %2, i64 0, i64 0
%5 = call i32 @snprintf(i8* %4, i32 255, i8* getelementptr inbounds ([29 x i8], [29 x i8]* @.str, i64 0, i64 0), i32 %0)
%6 = call i32* @fopen(i8* %4, i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str.1, i64 0, i64 0))
%7 = bitcast i32* %3 to i8*
store i32 0, i32* %3
%8 = call i32 @fscanf(i32* %6, i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str.2, i64 0, i64 0), i32* %3)
%9 = call i32 @fclose(i32* %6)
%10 = load i32, i32* %3
ret i32 %10
}