#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 letter;
  printf("Enter an upper case letter: ");
  scanf("%c", &letter);
  if (letter >= 65 && letter <= 90)
    printf("Lower case: %c \n", letter + 32);
  else
    printf("Input is not an upper case letter\n");
}


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    0xed9(%rip),%rdi
lea    -0x5(%rbp),%rsi
call   1040 <scanf@plt>
movsbl -0x5(%rbp),%eax
cmp    $0x41,%eax
jl     1181 <main+0x61>
movsbl -0x5(%rbp),%eax
cmp    $0x5a,%eax
jg     1181 <main+0x61>
movsbl -0x5(%rbp),%esi
add    $0x20,%esi
lea    0xeab(%rip),%rdi
mov    $0x0,%al
call   1030 <printf@plt>
jmp    118f <main+0x6f>
lea    0xea9(%rip),%rdi
mov    $0x0,%al
call   1030 <printf@plt>
mov    -0x4(%rbp),%eax
add    $0x10,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<main>:
push   %rax
lea    0xec8(%rip),%rdi
xor    %eax,%eax
call   1040 <printf@plt>
lea    0xed7(%rip),%rdi
lea    0x7(%rsp),%rsi
call   1050 <scanf@plt>
movzbl 0x7(%rsp),%esi
lea    -0x41(%rsi),%eax
cmp    $0x19,%al
ja     116f <main+0x3f>
add    $0x20,%esi
lea    0xeba(%rip),%rdi
xor    %eax,%eax
call   1040 <printf@plt>
jmp    117b <main+0x4b>
lea    0xebb(%rip),%rdi
call   1030 <puts@plt>
xor    %eax,%eax
pop    %rcx
ret

LLVM IR (-O0):
@.str = [29 x i8] c"Enter an upper case letter: \00"
@.str.1 = [3 x i8] c"%c\00"
@.str.2 = [17 x i8] c"Lower case: %c \0A\00"
@.str.3 = [35 x i8] c"Input is not an upper case letter\0A\00"
define i32 @main() {
%1 = alloca i32
%2 = alloca i8
store i32 0, i32* %1
%3 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([29 x i8], [29 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 %17
8: ; preds = %0
%9 = load i8, i8* %2
%10 = sext i8 %9 to i32
%11 = icmp sle i32 %10, 90
br i1 %11, label %12, label %17
12: ; preds = %8
%13 = load i8, i8* %2
%14 = sext i8 %13 to i32
%15 = add nsw i32 %14, 32
%16 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([17 x i8], [17 x i8]* @.str.2, i64 0, i64 0), i32 %15)
br label %19
17: ; preds = %8, %0
%18 = call i32 (i8*, ...) @printf(i8* getelementptr inbounds ([35 x i8], [35 x i8]* @.str.3, i64 0, i64 0))
br label %19
19: ; preds = %17, %12
%20 = load i32, i32* %1
ret i32 %20
}

LLVM IR (-O2):
@.str = [29 x i8] c"Enter an upper case letter: \00"
@.str.1 = [3 x i8] c"%c\00"
@.str.2 = [17 x i8] c"Lower case: %c \0A\00"
@str = [34 x i8] c"Input is not an upper case letter\00"
define i32 @main() {
%1 = alloca i8
%2 = tail call i32 (i8*, ...) @printf(i8* dereferenceable(1) getelementptr inbounds ([29 x i8], [29 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 = add i8 %4, -65
%6 = icmp ult i8 %5, 26
br i1 %6, label %7, label %11
7: ; preds = %0
%8 = zext i8 %4 to i32
%9 = add nuw nsw i32 %8, 32
%10 = call i32 (i8*, ...) @printf(i8* dereferenceable(1) getelementptr inbounds ([17 x i8], [17 x i8]* @.str.2, i64 0, i64 0), i32 %9)
br label %13
11: ; preds = %0
%12 = call i32 @puts(i8* dereferenceable(1) getelementptr inbounds ([34 x i8], [34 x i8]* @str, i64 0, i64 0))
br label %13
13: ; preds = %11, %7
ret i32 0
}