#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 *, int *);
int main(void) {
  int grade;
  printf("Enter numerical grade: ");
  scanf("%d", &grade);
  grade = grade / 10;
  printf("Letter grade: ");
  switch (grade) {
  case 10:
  case 9:
    printf("A\n");
    break;
  case 8:
    printf("B\n");
    break;
  case 7:
    printf("C\n");
    break;
  case 6:
    printf("D\n");
    break;
  default:
    printf("F\n");
  }
  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    0xeea(%rip),%rdi
lea    -0x8(%rbp),%rsi
call   1040 <scanf@plt>
movslq -0x8(%rbp),%rax
imul   $0x66666667,%rax,%rax
mov    %rax,%rcx
shr    $0x3f,%rcx
sar    $0x22,%rax
add    %ecx,%eax
mov    %eax,-0x8(%rbp)
lea    0xec2(%rip),%rdi
call   1030 <printf@plt>
mov    -0x8(%rbp),%eax
add    $0xfffffffa,%eax
mov    %eax,%ecx
mov    %rcx,-0x10(%rbp)
sub    $0x4,%eax
ja     11df <main+0xbf>
mov    -0x10(%rbp),%rax
lea    0xe6e(%rip),%rcx
movslq (%rcx,%rax,4),%rax
add    %rcx,%rax
jmp    *%rax
lea    0xe9c(%rip),%rdi
call   1030 <printf@plt>
jmp    11eb <main+0xcb>
lea    0xe8e(%rip),%rdi
call   1030 <printf@plt>
jmp    11eb <main+0xcb>
lea    0xe80(%rip),%rdi
call   1030 <printf@plt>
jmp    11eb <main+0xcb>
lea    0xe72(%rip),%rdi
call   1030 <printf@plt>
jmp    11eb <main+0xcb>
lea    0xe64(%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    0xed4(%rip),%rdi
lea    0x4(%rsp),%rsi
call   1050 <scanf@plt>
movslq 0x4(%rsp),%rax
imul   $0x66666667,%rax,%rax
mov    %rax,%rcx
shr    $0x3f,%rcx
sar    $0x22,%rax
add    %ecx,%eax
mov    %eax,0x4(%rsp)
lea    0xea9(%rip),%rdi
call   1040 <printf@plt>
mov    0x4(%rsp),%eax
add    $0xfffffffa,%eax
cmp    $0x4,%eax
ja     1195 <main+0x65>
cltq
lea    0xea8(%rip),%rcx
movslq (%rcx,%rax,4),%rdi
add    %rcx,%rdi
jmp    119c <main+0x6c>
lea    0xe96(%rip),%rdi
call   1030 <puts@plt>
xor    %eax,%eax
pop    %rcx
ret

LLVM IR (-O0):
@.str = [24 x i8] c"Enter numerical grade: \00"
@.str.1 = [3 x i8] c"%d\00"
@.str.2 = [15 x i8] c"Letter grade: \00"
@.str.3 = [3 x i8] c"A\0A\00"
@.str.4 = [3 x i8] c"B\0A\00"
@.str.5 = [3 x i8] c"C\0A\00"
@.str.6 = [3 x i8] c"D\0A\00"
@.str.7 = [3 x i8] c"F\0A\00"
define i32 @main() {
%1 = alloca i32
%2 = alloca i32
store i32 0, i32* %1
%3 = call i32 @printf(i8* getelementptr inbounds ([24 x i8], [24 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), i32* %2)
%5 = load i32, i32* %2
%6 = sdiv i32 %5, 10
store i32 %6, i32* %2
%7 = call i32 @printf(i8* getelementptr inbounds ([15 x i8], [15 x i8]* @.str.2, i64 0, i64 0))
%8 = load i32, i32* %2
switch i32 %8, label %17 [
i32 10, label %9
i32 9, label %9
i32 8, label %11
i32 7, label %13
i32 6, label %15
]
9: ; preds = %0, %0
%10 = call i32 @printf(i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str.3, i64 0, i64 0))
br label %19
11: ; preds = %0
%12 = call i32 @printf(i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str.4, i64 0, i64 0))
br label %19
13: ; preds = %0
%14 = call i32 @printf(i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str.5, i64 0, i64 0))
br label %19
15: ; preds = %0
%16 = call i32 @printf(i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str.6, i64 0, i64 0))
br label %19
17: ; preds = %0
%18 = call i32 @printf(i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str.7, i64 0, i64 0))
br label %19
19: ; preds = %17, %15, %13, %11, %9
ret i32 0
}

LLVM IR (-O2):
@.str = [24 x i8] c"Enter numerical grade: \00"
@.str.1 = [3 x i8] c"%d\00"
@.str.2 = [15 x i8] c"Letter grade: \00"
@str = [2 x i8] c"D\00"
@str.8 = [2 x i8] c"C\00"
@str.9 = [2 x i8] c"B\00"
@str.10 = [2 x i8] c"A\00"
@str.11 = [2 x i8] c"F\00"
@reltable.main = [5 x i32] [i32 trunc (i64 sub (i64 ptrtoint ([2 x i8]* @str to i64), i64 ptrtoint ([5 x i32]* @reltable.main to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([2 x i8]* @str.8 to i64), i64 ptrtoint ([5 x i32]* @reltable.main to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([2 x i8]* @str.9 to i64), i64 ptrtoint ([5 x i32]* @reltable.main to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([2 x i8]* @str.10 to i64), i64 ptrtoint ([5 x i32]* @reltable.main to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([2 x i8]* @str.10 to i64), i64 ptrtoint ([5 x i32]* @reltable.main to i64)) to i32)]
define i32 @main() {
%1 = alloca i32
%2 = bitcast i32* %1 to i8*
%3 = tail call i32 @printf(i8* dereferenceable(1) getelementptr inbounds ([24 x i8], [24 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), i32* %1)
%5 = load i32, i32* %1
%6 = sdiv i32 %5, 10
store i32 %6, i32* %1
%7 = call i32 @printf(i8* dereferenceable(1) getelementptr inbounds ([15 x i8], [15 x i8]* @.str.2, i64 0, i64 0))
%8 = load i32, i32* %1
%9 = add i32 %8, -6
%10 = icmp ult i32 %9, 5
br i1 %10, label %11, label %15
11: ; preds = %0
%12 = sext i32 %9 to i64
%13 = shl i64 %12, 2
%14 = call i8* @llvm.load.relative.i64(i8* bitcast ([5 x i32]* @reltable.main to i8*), i64 %13)
br label %15
15: ; preds = %0, %11
%16 = phi i8* [ %14, %11 ], [ getelementptr inbounds ([2 x i8], [2 x i8]* @str.11, i64 0, i64 0), %0 ]
%17 = call i32 @puts(i8* dereferenceable(1) %16)
ret i32 0
}