#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*/ getchar();
int /*<<< orphan*/ printf(char *);
int /*<<< orphan*/ scanf(char *, int *);
int menu() {
  int option = 0;
  printf("MAIN MENU\n==========\n");
  printf("1. Input Text\n");
  printf("2. Encrypt\n");
  printf("3. Decrypt\n");
  printf("4. Exit\n");
  printf("Selection: ");
  scanf("%d", &option);
  getchar();
  if (option > 4 || option < 0) {
    option = 5;
  }
  return option;
}


x86 assembly (clang, -O0):
<menu>:
push   %rbp
mov    %rsp,%rbp
sub    $0x10,%rsp
movl   $0x0,-0x4(%rbp)
lea    0xeba(%rip),%rdi
call   1030 <printf@plt>
lea    0xec4(%rip),%rdi
call   1030 <printf@plt>
lea    0xec7(%rip),%rdi
call   1030 <printf@plt>
lea    0xec7(%rip),%rdi
call   1030 <printf@plt>
lea    0xec7(%rip),%rdi
call   1030 <printf@plt>
lea    0xec4(%rip),%rdi
call   1030 <printf@plt>
lea    0xec4(%rip),%rdi
lea    -0x4(%rbp),%rsi
call   1050 <scanf@plt>
mov    $0x0,%al
call   1040 <getchar@plt>
cmpl   $0x4,-0x4(%rbp)
jg     11b2 <menu+0x82>
cmpl   $0x0,-0x4(%rbp)
jge    11b9 <menu+0x89>
movl   $0x5,-0x4(%rbp)
mov    -0x4(%rbp),%eax
add    $0x10,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<menu>:
push   %rax
movl   $0x0,0x4(%rsp)
lea    0xebf(%rip),%rdi
call   1030 <puts@plt>
lea    0xec8(%rip),%rdi
call   1030 <puts@plt>
lea    0xeca(%rip),%rdi
call   1030 <puts@plt>
lea    0xec9(%rip),%rdi
call   1030 <puts@plt>
lea    0xec8(%rip),%rdi
call   1030 <puts@plt>
lea    0xe74(%rip),%rdi
call   1040 <printf@plt>
lea    0xe74(%rip),%rdi
lea    0x4(%rsp),%rsi
call   1060 <scanf@plt>
xor    %eax,%eax
call   1050 <getchar@plt>
mov    0x4(%rsp),%ecx
cmp    $0x5,%ecx
mov    $0x5,%eax
cmovb  %ecx,%eax
pop    %rcx
ret

LLVM IR (-O0):
@.str = [22 x i8] c"MAIN MENU\0A==========\0A\00"
@.str.1 = [15 x i8] c"1. Input Text\0A\00"
@.str.2 = [12 x i8] c"2. Encrypt\0A\00"
@.str.3 = [12 x i8] c"3. Decrypt\0A\00"
@.str.4 = [9 x i8] c"4. Exit\0A\00"
@.str.5 = [12 x i8] c"Selection: \00"
@.str.6 = [3 x i8] c"%d\00"
define i32 @menu() {
%1 = alloca i32
store i32 0, i32* %1
%2 = call i32 @printf(i8* getelementptr inbounds ([22 x i8], [22 x i8]* @.str, i64 0, i64 0))
%3 = call i32 @printf(i8* getelementptr inbounds ([15 x i8], [15 x i8]* @.str.1, i64 0, i64 0))
%4 = call i32 @printf(i8* getelementptr inbounds ([12 x i8], [12 x i8]* @.str.2, i64 0, i64 0))
%5 = call i32 @printf(i8* getelementptr inbounds ([12 x i8], [12 x i8]* @.str.3, i64 0, i64 0))
%6 = call i32 @printf(i8* getelementptr inbounds ([9 x i8], [9 x i8]* @.str.4, i64 0, i64 0))
%7 = call i32 @printf(i8* getelementptr inbounds ([12 x i8], [12 x i8]* @.str.5, i64 0, i64 0))
%8 = call i32 @scanf(i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str.6, i64 0, i64 0), i32* %1)
%9 = call i32 (...) @getchar()
%10 = load i32, i32* %1
%11 = icmp sgt i32 %10, 4
br i1 %11, label %15, label %12
12: ; preds = %0
%13 = load i32, i32* %1
%14 = icmp slt i32 %13, 0
br i1 %14, label %15, label %16
15: ; preds = %12, %0
store i32 5, i32* %1
br label %16
16: ; preds = %15, %12
%17 = load i32, i32* %1
ret i32 %17
}

LLVM IR (-O2):
@.str.5 = [12 x i8] c"Selection: \00"
@.str.6 = [3 x i8] c"%d\00"
@str = [21 x i8] c"MAIN MENU\0A==========\00"
@str.7 = [14 x i8] c"1. Input Text\00"
@str.8 = [11 x i8] c"2. Encrypt\00"
@str.9 = [11 x i8] c"3. Decrypt\00"
@str.10 = [8 x i8] c"4. Exit\00"
define i32 @menu() {
%1 = alloca i32
%2 = bitcast i32* %1 to i8*
store i32 0, i32* %1
%3 = tail call i32 @puts(i8* dereferenceable(1) getelementptr inbounds ([21 x i8], [21 x i8]* @str, i64 0, i64 0))
%4 = tail call i32 @puts(i8* dereferenceable(1) getelementptr inbounds ([14 x i8], [14 x i8]* @str.7, i64 0, i64 0))
%5 = tail call i32 @puts(i8* dereferenceable(1) getelementptr inbounds ([11 x i8], [11 x i8]* @str.8, i64 0, i64 0))
%6 = tail call i32 @puts(i8* dereferenceable(1) getelementptr inbounds ([11 x i8], [11 x i8]* @str.9, i64 0, i64 0))
%7 = tail call i32 @puts(i8* dereferenceable(1) getelementptr inbounds ([8 x i8], [8 x i8]* @str.10, i64 0, i64 0))
%8 = tail call i32 @printf(i8* dereferenceable(1) getelementptr inbounds ([12 x i8], [12 x i8]* @.str.5, i64 0, i64 0))
%9 = call i32 @scanf(i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str.6, i64 0, i64 0), i32* %1)
%10 = call i32 (...) @getchar()
%11 = load i32, i32* %1
%12 = icmp ult i32 %11, 5
%13 = select i1 %12, i32 %11, i32 5
ret i32 %13
}