#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*/ exit(int);
int /*<<< orphan*/ fclose(int /*<<< orphan*/ *);
int /*<<< orphan*/ *fopen(char *, char *);
int /*<<< orphan*/ fscanf(int /*<<< orphan*/ *, char *, int *);
int /*<<< orphan*/ printf(char *, ...);
int main() {
  int num;
  FILE *fptr;
  if ((fptr = fopen("program.txt", "r")) == NULL) {
    printf("Error! opening file");
    exit(1);
  }
  fscanf(fptr, "%d", &num);
  printf("Value of n=%d", num);
  fclose(fptr);
  return 0;
}


x86 assembly (clang, -O0):
<main>:
push   %rbp
mov    %rsp,%rbp
sub    $0x10,%rsp
movl   $0x0,-0x4(%rbp)
lea    0xe9a(%rip),%rdi
lea    0xe9f(%rip),%rsi
call   1060 <fopen@plt>
mov    %rax,-0x10(%rbp)
cmp    $0x0,%rax
jne    1198 <main+0x48>
lea    0xe87(%rip),%rdi
mov    $0x0,%al
call   1040 <printf@plt>
mov    $0x1,%edi
call   1070 <exit@plt>
mov    -0x10(%rbp),%rdi
lea    0xe8a(%rip),%rsi
lea    -0x8(%rbp),%rdx
call   1050 <fscanf@plt>
mov    -0x8(%rbp),%esi
lea    0xe6c(%rip),%rdi
mov    $0x0,%al
call   1040 <printf@plt>
mov    -0x10(%rbp),%rdi
call   1030 <fclose@plt>
xor    %eax,%eax
add    $0x10,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<main>:
push   %rbx
sub    $0x10,%rsp
lea    0xea4(%rip),%rdi
lea    0xea9(%rip),%rsi
call   1060 <fopen@plt>
test   %rax,%rax
je     11a6 <main+0x56>
mov    %rax,%rbx
lea    0xeb6(%rip),%rsi
lea    0xc(%rsp),%rdx
mov    %rax,%rdi
call   1050 <fscanf@plt>
mov    0xc(%rsp),%esi
lea    0xe93(%rip),%rdi
xor    %eax,%eax
call   1040 <printf@plt>
mov    %rbx,%rdi
call   1030 <fclose@plt>
xor    %eax,%eax
add    $0x10,%rsp
pop    %rbx
ret
lea    0xe61(%rip),%rdi
xor    %eax,%eax
call   1040 <printf@plt>
mov    $0x1,%edi
call   1070 <exit@plt>

LLVM IR (-O0):
@.str = [12 x i8] c"program.txt\00"
@.str.1 = [2 x i8] c"r\00"
@.str.2 = [20 x i8] c"Error! opening file\00"
@.str.3 = [3 x i8] c"%d\00"
@.str.4 = [14 x i8] c"Value of n=%d\00"
define i32 @main() {
%1 = alloca i32
%2 = alloca i32
%3 = alloca i32*
store i32 0, i32* %1
%4 = call i32* @fopen(i8* getelementptr inbounds ([12 x i8], [12 x i8]* @.str, i64 0, i64 0), i8* getelementptr inbounds ([2 x i8], [2 x i8]* @.str.1, i64 0, i64 0))
store i32* %4, i32** %3
%5 = icmp eq i32* %4, null
br i1 %5, label %6, label %9
6: ; preds = %0
%7 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([20 x i8], [20 x i8]* @.str.2, i64 0, i64 0))
%8 = call i32 @exit(i32 1)
unreachable
9: ; preds = %0
%10 = load i32*, i32** %3
%11 = call i32 @fscanf(i32* %10, i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str.3, i64 0, i64 0), i32* %2)
%12 = load i32, i32* %2
%13 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([14 x i8], [14 x i8]* @.str.4, i64 0, i64 0), i32 %12)
%14 = load i32*, i32** %3
%15 = call i32 @fclose(i32* %14)
ret i32 0
}

LLVM IR (-O2):
@.str = [12 x i8] c"program.txt\00"
@.str.1 = [2 x i8] c"r\00"
@.str.2 = [20 x i8] c"Error! opening file\00"
@.str.3 = [3 x i8] c"%d\00"
@.str.4 = [14 x i8] c"Value of n=%d\00"
define i32 @main() {
%1 = alloca i32
%2 = bitcast i32* %1 to i8*
%3 = tail call i32* @fopen(i8* getelementptr inbounds ([12 x i8], [12 x i8]* @.str, i64 0, i64 0), i8* getelementptr inbounds ([2 x i8], [2 x i8]* @.str.1, i64 0, i64 0))
%4 = icmp eq i32* %3, null
br i1 %4, label %5, label %8
5: ; preds = %0
%6 = tail call i32 (i8*, ...) @printf(i8* dereferenceable(1) getelementptr inbounds ([20 x i8], [20 x i8]* @.str.2, i64 0, i64 0))
%7 = tail call i32 @exit(i32 1)
unreachable
8: ; preds = %0
%9 = call i32 @fscanf(i32* %3, i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str.3, i64 0, i64 0), i32* %1)
%10 = load i32, i32* %1
%11 = call i32 (i8*, ...) @printf(i8* dereferenceable(1) getelementptr inbounds ([14 x i8], [14 x i8]* @.str.4, i64 0, i64 0), i32 %10)
%12 = call i32 @fclose(i32* %3)
ret i32 0
}