#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*/ printf(char *);
int /*<<< orphan*/ scanf(char *, char *);
int main() {
  char x;
  printf("Enter a letter: ");
  scanf("%c", &x);
  if ((x >= 'A' && x <= 'Z') || (x >= 'a' && x <= 'z')) {
    if (x == 'a' || x == 'A' || x == 'E' || x == 'e' || x == 'O' || x == 'o' ||
        x == 'I' || x == 'i' || x == 'U' || x == 'u')
      printf("It is a  vowel.\n");
    else
      printf("It is a consonant.\n");
  } else
    printf("You didn't enter a letter.\n");
  return 0;
}


x86 assembly (clang, -O0):
<main>:
push   %rbp
mov    %rsp,%rbp
sub    $0x10,%rsp
movl   $0x0,-0x4(%rbp)
lea    0xeca(%rip),%rdi
call   1030 <printf@plt>
lea    0xecf(%rip),%rdi
lea    -0x5(%rbp),%rsi
call   1040 <scanf@plt>
movsbl -0x5(%rbp),%eax
cmp    $0x41,%eax
jl     1165 <main+0x45>
movsbl -0x5(%rbp),%eax
cmp    $0x5a,%eax
jle    117f <main+0x5f>
movsbl -0x5(%rbp),%eax
cmp    $0x61,%eax
jl     1223 <main+0x103>
movsbl -0x5(%rbp),%eax
cmp    $0x7a,%eax
jg     1223 <main+0x103>
movsbl -0x5(%rbp),%eax
cmp    $0x61,%eax
je     1201 <main+0xe1>
movsbl -0x5(%rbp),%eax
cmp    $0x41,%eax
je     1201 <main+0xe1>
movsbl -0x5(%rbp),%eax
cmp    $0x45,%eax
je     1201 <main+0xe1>
movsbl -0x5(%rbp),%eax
cmp    $0x65,%eax
je     1201 <main+0xe1>
movsbl -0x5(%rbp),%eax
cmp    $0x4f,%eax
je     1201 <main+0xe1>
movsbl -0x5(%rbp),%eax
cmp    $0x6f,%eax
je     1201 <main+0xe1>
movsbl -0x5(%rbp),%eax
cmp    $0x49,%eax
je     1201 <main+0xe1>
movsbl -0x5(%rbp),%eax
cmp    $0x69,%eax
je     1201 <main+0xe1>
movsbl -0x5(%rbp),%eax
cmp    $0x55,%eax
je     1201 <main+0xe1>
movsbl -0x5(%rbp),%eax
cmp    $0x75,%eax
jne    1212 <main+0xf2>
lea    0xe0c(%rip),%rdi
call   1030 <printf@plt>
jmp    121e <main+0xfe>
lea    0xe0c(%rip),%rdi
call   1030 <printf@plt>
jmp    122f <main+0x10f>
lea    0xe0f(%rip),%rdi
call   1030 <printf@plt>
xor    %eax,%eax
add    $0x10,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<main>:
push   %rax
lea    0xec8(%rip),%rdi
call   1040 <printf@plt>
lea    0xecd(%rip),%rdi
lea    0x7(%rsp),%rsi
call   1050 <scanf@plt>
mov    0x7(%rsp),%al
mov    %eax,%ecx
and    $0xdf,%cl
add    $0xbf,%cl
cmp    $0x19,%cl
ja     1181 <main+0x51>
add    $0xbf,%al
cmp    $0x34,%al
ja     1191 <main+0x61>
movzbl %al,%eax
movabs $0x10411100104111,%rcx
bt     %rax,%rcx
jae    1191 <main+0x61>
lea    0xec3(%rip),%rdi
jmp    1188 <main+0x58>
lea    0xe8c(%rip),%rdi
call   1030 <puts@plt>
xor    %eax,%eax
pop    %rcx
ret
lea    0xe97(%rip),%rdi
jmp    1188 <main+0x58>

LLVM IR (-O0):
@.str = [17 x i8] c"Enter a letter: \00"
@.str.1 = [3 x i8] c"%c\00"
@.str.2 = [17 x i8] c"It is a vowel.\0A\00"
@.str.3 = [20 x i8] c"It is a consonant.\0A\00"
@.str.4 = [28 x i8] c"You didn't enter a letter.\0A\00"
define i32 @main() {
%1 = alloca i32
%2 = alloca i8
store i32 0, i32* %1
%3 = call i32 @printf(i8* getelementptr inbounds ([17 x i8], [17 x i8]* @.str, i64 0, i64 0))
%4 = call i32 @scanf(i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str.1, i64 0, i64 0), i8* %2)
%5 = load i8, i8* %2
%6 = sext i8 %5 to i32
%7 = icmp sge i32 %6, 65
br i1 %7, label %8, label %12
8: ; preds = %0
%9 = load i8, i8* %2
%10 = sext i8 %9 to i32
%11 = icmp sle i32 %10, 90
br i1 %11, label %20, label %12
12: ; preds = %8, %0
%13 = load i8, i8* %2
%14 = sext i8 %13 to i32
%15 = icmp sge i32 %14, 97
br i1 %15, label %16, label %65
16: ; preds = %12
%17 = load i8, i8* %2
%18 = sext i8 %17 to i32
%19 = icmp sle i32 %18, 122
br i1 %19, label %20, label %65
20: ; preds = %16, %8
%21 = load i8, i8* %2
%22 = sext i8 %21 to i32
%23 = icmp eq i32 %22, 97
br i1 %23, label %60, label %24
24: ; preds = %20
%25 = load i8, i8* %2
%26 = sext i8 %25 to i32
%27 = icmp eq i32 %26, 65
br i1 %27, label %60, label %28
28: ; preds = %24
%29 = load i8, i8* %2
%30 = sext i8 %29 to i32
%31 = icmp eq i32 %30, 69
br i1 %31, label %60, label %32
32: ; preds = %28
%33 = load i8, i8* %2
%34 = sext i8 %33 to i32
%35 = icmp eq i32 %34, 101
br i1 %35, label %60, label %36
36: ; preds = %32
%37 = load i8, i8* %2
%38 = sext i8 %37 to i32
%39 = icmp eq i32 %38, 79
br i1 %39, label %60, label %40
40: ; preds = %36
%41 = load i8, i8* %2
%42 = sext i8 %41 to i32
%43 = icmp eq i32 %42, 111
br i1 %43, label %60, label %44
44: ; preds = %40
%45 = load i8, i8* %2
%46 = sext i8 %45 to i32
%47 = icmp eq i32 %46, 73
br i1 %47, label %60, label %48
48: ; preds = %44
%49 = load i8, i8* %2
%50 = sext i8 %49 to i32
%51 = icmp eq i32 %50, 105
br i1 %51, label %60, label %52
52: ; preds = %48
%53 = load i8, i8* %2
%54 = sext i8 %53 to i32
%55 = icmp eq i32 %54, 85
br i1 %55, label %60, label %56
56: ; preds = %52
%57 = load i8, i8* %2
%58 = sext i8 %57 to i32
%59 = icmp eq i32 %58, 117
br i1 %59, label %60, label %62
60: ; preds = %56, %52, %48, %44, %40, %36, %32, %28, %24, %20
%61 = call i32 @printf(i8* getelementptr inbounds ([17 x i8], [17 x i8]* @.str.2, i64 0, i64 0))
br label %64
62: ; preds = %56
%63 = call i32 @printf(i8* getelementptr inbounds ([20 x i8], [20 x i8]* @.str.3, i64 0, i64 0))
br label %64
64: ; preds = %62, %60
br label %67
65: ; preds = %16, %12
%66 = call i32 @printf(i8* getelementptr inbounds ([28 x i8], [28 x i8]* @.str.4, i64 0, i64 0))
br label %67
67: ; preds = %65, %64
ret i32 0
}

LLVM IR (-O2):
@.str = [17 x i8] c"Enter a letter: \00"
@.str.1 = [3 x i8] c"%c\00"
@str = [27 x i8] c"You didn't enter a letter.\00"
@str.5 = [19 x i8] c"It is a consonant.\00"
@str.6 = [16 x i8] c"It is a vowel.\00"
define i32 @main() {
%1 = alloca i8
%2 = tail call i32 @printf(i8* dereferenceable(1) getelementptr inbounds ([17 x i8], [17 x i8]* @.str, i64 0, i64 0))
%3 = call i32 @scanf(i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str.1, i64 0, i64 0), i8* %1)
%4 = load i8, i8* %1
%5 = and i8 %4, -33
%6 = add i8 %5, -65
%7 = icmp ult i8 %6, 26
br i1 %7, label %8, label %10
8: ; preds = %0
switch i8 %4, label %9 [
i8 117, label %10
i8 111, label %10
i8 105, label %10
i8 101, label %10
i8 97, label %10
i8 85, label %10
i8 79, label %10
i8 73, label %10
i8 69, label %10
i8 65, label %10
]
9: ; preds = %8
br label %10
10: ; preds = %0, %8, %8, %8, %8, %8, %8, %8, %8, %8, %8, %9
%11 = phi i8* [ getelementptr inbounds ([19 x i8], [19 x i8]* @str.5, i64 0, i64 0), %9 ], [ getelementptr inbounds ([16 x i8], [16 x i8]* @str.6, i64 0, i64 0), %8 ], [ getelementptr inbounds ([16 x i8], [16 x i8]* @str.6, i64 0, i64 0), %8 ], [ getelementptr inbounds ([16 x i8], [16 x i8]* @str.6, i64 0, i64 0), %8 ], [ getelementptr inbounds ([16 x i8], [16 x i8]* @str.6, i64 0, i64 0), %8 ], [ getelementptr inbounds ([16 x i8], [16 x i8]* @str.6, i64 0, i64 0), %8 ], [ getelementptr inbounds ([16 x i8], [16 x i8]* @str.6, i64 0, i64 0), %8 ], [ getelementptr inbounds ([16 x i8], [16 x i8]* @str.6, i64 0, i64 0), %8 ], [ getelementptr inbounds ([16 x i8], [16 x i8]* @str.6, i64 0, i64 0), %8 ], [ getelementptr inbounds ([16 x i8], [16 x i8]* @str.6, i64 0, i64 0), %8 ], [ getelementptr inbounds ([16 x i8], [16 x i8]* @str.6, i64 0, i64 0), %8 ], [ getelementptr inbounds ([27 x i8], [27 x i8]* @str, i64 0, i64 0), %0 ]
%12 = call i32 @puts(i8* dereferenceable(1) %11)
ret i32 0
}