#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 grade;
  printf("Input Grade: ");
  scanf("%c", &grade);
  switch (grade) {
  case 'A':
    printf("A is 90-100");
    break;
  case 'B':
    printf("B is 80-89");
    break;
  case 'C':
    printf("C is 70-79");
    break;
  case 'D':
    printf("D is 60-69");
    break;
  case 'E':
    printf("E is 0-69");
    break;
  default:
    printf("error");
    break;
  }
  return 0;
}


x86 assembly (clang, -O0):
<main>:
push   %rbp
mov    %rsp,%rbp
sub    $0x10,%rsp
movl   $0x0,-0x4(%rbp)
lea    0xede(%rip),%rdi
call   1030 <printf@plt>
lea    0xee0(%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    $0x4,%eax
ja     11ca <main+0xaa>
mov    -0x10(%rbp),%rax
lea    0xe94(%rip),%rcx
movslq (%rcx,%rax,4),%rax
add    %rcx,%rax
jmp    *%rax
lea    0xea9(%rip),%rdi
call   1030 <printf@plt>
jmp    11d6 <main+0xb6>
lea    0xea4(%rip),%rdi
call   1030 <printf@plt>
jmp    11d6 <main+0xb6>
lea    0xe9e(%rip),%rdi
call   1030 <printf@plt>
jmp    11d6 <main+0xb6>
lea    0xe98(%rip),%rdi
call   1030 <printf@plt>
jmp    11d6 <main+0xb6>
lea    0xe92(%rip),%rdi
call   1030 <printf@plt>
jmp    11d6 <main+0xb6>
lea    0xe8b(%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
call   1030 <printf@plt>
lea    0xeda(%rip),%rdi
lea    0x7(%rsp),%rsi
call   1040 <scanf@plt>
movsbq 0x7(%rsp),%rax
add    $0xffffffffffffffbf,%rax
cmp    $0x4,%eax
ja     115d <main+0x3d>
lea    0xefc(%rip),%rcx
movslq (%rcx,%rax,4),%rdi
add    %rcx,%rdi
jmp    1164 <main+0x44>
lea    0xee4(%rip),%rdi
call   1030 <printf@plt>
xor    %eax,%eax
pop    %rcx
ret

LLVM IR (-O0):
@.str = [14 x i8] c"Input Grade: \00"
@.str.1 = [3 x i8] c"%c\00"
@.str.2 = [12 x i8] c"A is 90-100\00"
@.str.3 = [11 x i8] c"B is 80-89\00"
@.str.4 = [11 x i8] c"C is 70-79\00"
@.str.5 = [11 x i8] c"D is 60-69\00"
@.str.6 = [10 x i8] c"E is 0-69\00"
@.str.7 = [6 x i8] c"error\00"
define i32 @main() {
%1 = alloca i32
%2 = alloca i8
store i32 0, i32* %1
%3 = call i32 @printf(i8* getelementptr inbounds ([14 x i8], [14 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
switch i32 %6, label %17 [
i32 65, label %7
i32 66, label %9
i32 67, label %11
i32 68, label %13
i32 69, label %15
]
7: ; preds = %0
%8 = call i32 @printf(i8* getelementptr inbounds ([12 x i8], [12 x i8]* @.str.2, i64 0, i64 0))
br label %19
9: ; preds = %0
%10 = call i32 @printf(i8* getelementptr inbounds ([11 x i8], [11 x i8]* @.str.3, i64 0, i64 0))
br label %19
11: ; preds = %0
%12 = call i32 @printf(i8* getelementptr inbounds ([11 x i8], [11 x i8]* @.str.4, i64 0, i64 0))
br label %19
13: ; preds = %0
%14 = call i32 @printf(i8* getelementptr inbounds ([11 x i8], [11 x i8]* @.str.5, i64 0, i64 0))
br label %19
15: ; preds = %0
%16 = call i32 @printf(i8* getelementptr inbounds ([10 x i8], [10 x i8]* @.str.6, i64 0, i64 0))
br label %19
17: ; preds = %0
%18 = call i32 @printf(i8* getelementptr inbounds ([6 x i8], [6 x i8]* @.str.7, i64 0, i64 0))
br label %19
19: ; preds = %17, %15, %13, %11, %9, %7
ret i32 0
}

LLVM IR (-O2):
@.str = [14 x i8] c"Input Grade: \00"
@.str.1 = [3 x i8] c"%c\00"
@.str.2 = [12 x i8] c"A is 90-100\00"
@.str.3 = [11 x i8] c"B is 80-89\00"
@.str.4 = [11 x i8] c"C is 70-79\00"
@.str.5 = [11 x i8] c"D is 60-69\00"
@.str.6 = [10 x i8] c"E is 0-69\00"
@.str.7 = [6 x i8] c"error\00"
@reltable.main = [5 x i32] [i32 trunc (i64 sub (i64 ptrtoint ([12 x i8]* @.str.2 to i64), i64 ptrtoint ([5 x i32]* @reltable.main to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([11 x i8]* @.str.3 to i64), i64 ptrtoint ([5 x i32]* @reltable.main to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([11 x i8]* @.str.4 to i64), i64 ptrtoint ([5 x i32]* @reltable.main to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([11 x i8]* @.str.5 to i64), i64 ptrtoint ([5 x i32]* @reltable.main to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([10 x i8]* @.str.6 to i64), i64 ptrtoint ([5 x i32]* @reltable.main to i64)) to i32)]
define i32 @main() {
%1 = alloca i8
%2 = tail call i32 @printf(i8* dereferenceable(1) getelementptr inbounds ([14 x i8], [14 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 = add nsw i32 %5, -65
%7 = icmp ult i32 %6, 5
br i1 %7, label %8, label %12
8: ; preds = %0
%9 = sext i32 %6 to i64
%10 = shl i64 %9, 2
%11 = call i8* @llvm.load.relative.i64(i8* bitcast ([5 x i32]* @reltable.main to i8*), i64 %10)
br label %12
12: ; preds = %0, %8
%13 = phi i8* [ %11, %8 ], [ getelementptr inbounds ([6 x i8], [6 x i8]* @.str.7, i64 0, i64 0), %0 ]
%14 = call i32 @printf(i8* dereferenceable(1) %13)
ret i32 0
}