#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 c;
  printf("Enter a character: ");
  scanf("%c", &c);
  if ((c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z'))
    printf("%c is an alphabet.", c);
  else
    printf("%c is not an alphabet.", c);
  return 0;
}


x86 assembly (clang, -O0):
<main>:
push   %rbp
mov    %rsp,%rbp
sub    $0x10,%rsp
movl   $0x0,-0x4(%rbp)
lea    0xeca(%rip),%rdi
mov    $0x0,%al
call   1030 <printf@plt>
lea    0xed0(%rip),%rdi
lea    -0x5(%rbp),%rsi
call   1040 <scanf@plt>
movsbl -0x5(%rbp),%eax
cmp    $0x61,%eax
jl     1167 <main+0x47>
movsbl -0x5(%rbp),%eax
cmp    $0x7a,%eax
jle    1181 <main+0x61>
movsbl -0x5(%rbp),%eax
cmp    $0x41,%eax
jl     1198 <main+0x78>
movsbl -0x5(%rbp),%eax
cmp    $0x5a,%eax
jg     1198 <main+0x78>
movsbl -0x5(%rbp),%esi
lea    0xe8b(%rip),%rdi
mov    $0x0,%al
call   1030 <printf@plt>
jmp    11aa <main+0x8a>
movsbl -0x5(%rbp),%esi
lea    0xe87(%rip),%rdi
mov    $0x0,%al
call   1030 <printf@plt>
xor    %eax,%eax
add    $0x10,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<main>:
push   %rax
lea    0xed8(%rip),%rdi
xor    %eax,%eax
call   1030 <printf@plt>
lea    0xede(%rip),%rdi
lea    0x7(%rsp),%rsi
call   1040 <scanf@plt>
movsbl 0x7(%rsp),%esi
mov    %esi,%eax
and    $0xdf,%al
add    $0xbf,%al
cmp    $0x1a,%al
lea    0xec3(%rip),%rax
lea    0xecf(%rip),%rdi
cmovb  %rax,%rdi
xor    %eax,%eax
call   1030 <printf@plt>
xor    %eax,%eax
pop    %rcx
ret

LLVM IR (-O0):
@.str = [20 x i8] c"Enter a character: \00"
@.str.1 = [3 x i8] c"%c\00"
@.str.2 = [19 x i8] c"%c is an alphabet.\00"
@.str.3 = [23 x i8] c"%c is not an alphabet.\00"
define i32 @main() {
%1 = alloca i32
%2 = alloca i8
store i32 0, i32* %1
%3 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([20 x i8], [20 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, 97
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, 122
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, 65
br i1 %15, label %16, label %24
16: ; preds = %12
%17 = load i8, i8* %2
%18 = sext i8 %17 to i32
%19 = icmp sle i32 %18, 90
br i1 %19, label %20, label %24
20: ; preds = %16, %8
%21 = load i8, i8* %2
%22 = sext i8 %21 to i32
%23 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([19 x i8], [19 x i8]* @.str.2, i64 0, i64 0), i32 %22)
br label %28
24: ; preds = %16, %12
%25 = load i8, i8* %2
%26 = sext i8 %25 to i32
%27 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([23 x i8], [23 x i8]* @.str.3, i64 0, i64 0), i32 %26)
br label %28
28: ; preds = %24, %20
ret i32 0
}

LLVM IR (-O2):
@.str = [20 x i8] c"Enter a character: \00"
@.str.1 = [3 x i8] c"%c\00"
@.str.2 = [19 x i8] c"%c is an alphabet.\00"
@.str.3 = [23 x i8] c"%c is not an alphabet.\00"
define i32 @main() {
%1 = alloca i8
%2 = tail call i32 (i8*, ...) @printf(i8* dereferenceable(1) getelementptr inbounds ([20 x i8], [20 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 = sext i8 %4 to i32
%6 = and i8 %4, -33
%7 = add i8 %6, -65
%8 = icmp ult i8 %7, 26
%9 = select i1 %8, i8* getelementptr inbounds ([19 x i8], [19 x i8]* @.str.2, i64 0, i64 0), i8* getelementptr inbounds ([23 x i8], [23 x i8]* @.str.3, i64 0, i64 0)
%10 = call i32 (i8*, ...) @printf(i8* dereferenceable(1) %9, i32 %5)
ret i32 0
}