#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(void) {
  char grade;
  scanf("%c", &grade);
  switch (grade) {
  case 'A':
    printf("Excellent!\n");
    break;
  case 'B':
    printf("Well done\n");
    break;
  case 'C':
    printf("You passed\n");
    break;
  case 'D':
    printf("Better try again\n");
    break;
  default:
    printf("Invalid grade\n");
  }
  return 0;
}


x86 assembly (clang, -O0):
<main>:
push   %rbp
mov    %rsp,%rbp
sub    $0x10,%rsp
movl   $0x0,-0x4(%rbp)
lea    0xeda(%rip),%rdi
lea    -0x5(%rbp),%rsi
call   1040 <scanf@plt>
movsbl -0x5(%rbp),%eax
add    $0xffffffbf,%eax
mov    %eax,%ecx
mov    %rcx,-0x10(%rbp)
sub    $0x3,%eax
ja     11ad <main+0x8d>
mov    -0x10(%rbp),%rax
lea    0xea0(%rip),%rcx
movslq (%rcx,%rax,4),%rax
add    %rcx,%rax
jmp    *%rax
lea    0xea3(%rip),%rdi
call   1030 <printf@plt>
jmp    11b9 <main+0x99>
lea    0xe9e(%rip),%rdi
call   1030 <printf@plt>
jmp    11b9 <main+0x99>
lea    0xe98(%rip),%rdi
call   1030 <printf@plt>
jmp    11b9 <main+0x99>
lea    0xe93(%rip),%rdi
call   1030 <printf@plt>
jmp    11b9 <main+0x99>
lea    0xe94(%rip),%rdi
call   1030 <printf@plt>
xor    %eax,%eax
add    $0x10,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<main>:
push   %rax
lea    0xed8(%rip),%rdi
lea    0x7(%rsp),%rsi
call   1040 <scanf@plt>
movsbq 0x7(%rsp),%rax
add    $0xffffffffffffffbf,%rax
cmp    $0x3,%eax
ja     1151 <main+0x31>
lea    0xefc(%rip),%rcx
movslq (%rcx,%rax,4),%rdi
add    %rcx,%rdi
jmp    1158 <main+0x38>
lea    0xedc(%rip),%rdi
call   1030 <puts@plt>
xor    %eax,%eax
pop    %rcx
ret

LLVM IR (-O0):
@.str = [3 x i8] c"%c\00"
@.str.1 = [12 x i8] c"Excellent!\0A\00"
@.str.2 = [11 x i8] c"Well done\0A\00"
@.str.3 = [12 x i8] c"You passed\0A\00"
@.str.4 = [18 x i8] c"Better try again\0A\00"
@.str.5 = [15 x i8] c"Invalid grade\0A\00"
define i32 @main() {
%1 = alloca i32
%2 = alloca i8
store i32 0, i32* %1
%3 = call i32 @scanf(i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str, i64 0, i64 0), i8* %2)
%4 = load i8, i8* %2
%5 = sext i8 %4 to i32
switch i32 %5, label %14 [
i32 65, label %6
i32 66, label %8
i32 67, label %10
i32 68, label %12
]
6: ; preds = %0
%7 = call i32 @printf(i8* getelementptr inbounds ([12 x i8], [12 x i8]* @.str.1, i64 0, i64 0))
br label %16
8: ; preds = %0
%9 = call i32 @printf(i8* getelementptr inbounds ([11 x i8], [11 x i8]* @.str.2, i64 0, i64 0))
br label %16
10: ; preds = %0
%11 = call i32 @printf(i8* getelementptr inbounds ([12 x i8], [12 x i8]* @.str.3, i64 0, i64 0))
br label %16
12: ; preds = %0
%13 = call i32 @printf(i8* getelementptr inbounds ([18 x i8], [18 x i8]* @.str.4, i64 0, i64 0))
br label %16
14: ; preds = %0
%15 = call i32 @printf(i8* getelementptr inbounds ([15 x i8], [15 x i8]* @.str.5, i64 0, i64 0))
br label %16
16: ; preds = %14, %12, %10, %8, %6
ret i32 0
}

LLVM IR (-O2):
@.str = [3 x i8] c"%c\00"
@str = [17 x i8] c"Better try again\00"
@str.6 = [11 x i8] c"You passed\00"
@str.7 = [10 x i8] c"Well done\00"
@str.8 = [11 x i8] c"Excellent!\00"
@str.9 = [14 x i8] c"Invalid grade\00"
@reltable.main = [4 x i32] [i32 trunc (i64 sub (i64 ptrtoint ([11 x i8]* @str.8 to i64), i64 ptrtoint ([4 x i32]* @reltable.main to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([10 x i8]* @str.7 to i64), i64 ptrtoint ([4 x i32]* @reltable.main to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([11 x i8]* @str.6 to i64), i64 ptrtoint ([4 x i32]* @reltable.main to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([17 x i8]* @str to i64), i64 ptrtoint ([4 x i32]* @reltable.main to i64)) to i32)]
define i32 @main() {
%1 = alloca i8
%2 = call i32 @scanf(i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str, i64 0, i64 0), i8* %1)
%3 = load i8, i8* %1
%4 = sext i8 %3 to i32
%5 = add nsw i32 %4, -65
%6 = icmp ult i32 %5, 4
br i1 %6, label %7, label %11
7: ; preds = %0
%8 = sext i32 %5 to i64
%9 = shl i64 %8, 2
%10 = call i8* @llvm.load.relative.i64(i8* bitcast ([4 x i32]* @reltable.main to i8*), i64 %9)
br label %11
11: ; preds = %0, %7
%12 = phi i8* [ %10, %7 ], [ getelementptr inbounds ([14 x i8], [14 x i8]* @str.9, i64 0, i64 0), %0 ]
%13 = call i32 @puts(i8* dereferenceable(1) %12)
ret i32 0
}