#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 *, float *);
int main(void) {
  float score;
  scanf("%f", &score);
  if (score >= 80 && score <= 100) {
    printf("A\n");
  } else {
    if (score >= 70 && score < 80) {
      printf("B\n");
    } else {
      if (score >= 60 && score < 70) {
        printf("C\n");
      } else {
        if (score >= 50 && score < 60) {
          printf("D\n");
        } else {
          if (score >= 0 && score < 50) {
            printf("F\n");
          } else {
            printf("Out of Range\n");
          }
        }
      }
    }
  }
}


x86 assembly (clang, -O0):
<main>:
push   %rbp
mov    %rsp,%rbp
sub    $0x10,%rsp
movl   $0x0,-0x4(%rbp)
lea    0xede(%rip),%rdi
lea    -0x8(%rbp),%rsi
call   1040 <scanf@plt>
movss  -0x8(%rbp),%xmm0
movss  0xeb4(%rip),%xmm1
ucomiss %xmm1,%xmm0
jb     1178 <main+0x58>
movss  0xea7(%rip),%xmm0
ucomiss -0x8(%rbp),%xmm0
jb     1178 <main+0x58>
lea    0xea9(%rip),%rdi
call   1030 <printf@plt>
jmp    1277 <main+0x157>
movss  -0x8(%rbp),%xmm0
movss  0xe83(%rip),%xmm1
ucomiss %xmm1,%xmm0
jb     11b1 <main+0x91>
movss  0xe6a(%rip),%xmm0
ucomiss -0x8(%rbp),%xmm0
jbe    11b1 <main+0x91>
lea    0xe73(%rip),%rdi
call   1030 <printf@plt>
jmp    1272 <main+0x152>
movss  -0x8(%rbp),%xmm0
movss  0xe4e(%rip),%xmm1
ucomiss %xmm1,%xmm0
jb     11ea <main+0xca>
movss  0xe39(%rip),%xmm0
ucomiss -0x8(%rbp),%xmm0
jbe    11ea <main+0xca>
lea    0xe3d(%rip),%rdi
call   1030 <printf@plt>
jmp    126d <main+0x14d>
movss  -0x8(%rbp),%xmm0
movss  0xe19(%rip),%xmm1
ucomiss %xmm1,%xmm0
jb     1223 <main+0x103>
movss  0xe04(%rip),%xmm0
ucomiss -0x8(%rbp),%xmm0
jbe    1223 <main+0x103>
lea    0xe07(%rip),%rdi
call   1030 <printf@plt>
jmp    1268 <main+0x148>
movss  -0x8(%rbp),%xmm0
xorps  %xmm1,%xmm1
ucomiss %xmm1,%xmm0
jb     1257 <main+0x137>
movss  0xdd4(%rip),%xmm0
ucomiss -0x8(%rbp),%xmm0
jbe    1257 <main+0x137>
lea    0xdd6(%rip),%rdi
call   1030 <printf@plt>
jmp    1263 <main+0x143>
lea    0xdc8(%rip),%rdi
call   1030 <printf@plt>
jmp    1268 <main+0x148>
jmp    126d <main+0x14d>
jmp    1272 <main+0x152>
jmp    1277 <main+0x157>
mov    -0x4(%rbp),%eax
add    $0x10,%rsp
pop    %rbp
ret

x86 assembly (clang, -O2):
<main>:
push   %rax
lea    0xeec(%rip),%rdi
lea    0x4(%rsp),%rsi
call   1040 <scanf@plt>
movss  0x4(%rsp),%xmm0
ucomiss 0xec1(%rip),%xmm0
jb     115a <main+0x3a>
movss  0xebb(%rip),%xmm1
ucomiss %xmm0,%xmm1
jb     115a <main+0x3a>
lea    0xed7(%rip),%rdi
jmp    11de <main+0xbe>
ucomiss 0xea7(%rip),%xmm0
jb     1179 <main+0x59>
movss  0xe95(%rip),%xmm1
ucomiss %xmm0,%xmm1
jbe    1179 <main+0x59>
lea    0xeb3(%rip),%rdi
jmp    11de <main+0xbe>
ucomiss 0xe8c(%rip),%xmm0
jb     1198 <main+0x78>
movss  0xe7e(%rip),%xmm1
ucomiss %xmm0,%xmm1
jbe    1198 <main+0x78>
lea    0xe92(%rip),%rdi
jmp    11de <main+0xbe>
ucomiss 0xe71(%rip),%xmm0
jb     11b7 <main+0x97>
movss  0xe63(%rip),%xmm1
ucomiss %xmm0,%xmm1
jbe    11b7 <main+0x97>
lea    0xe71(%rip),%rdi
jmp    11de <main+0xbe>
movss  0xe51(%rip),%xmm1
ucomiss %xmm0,%xmm1
lea    0xe5b(%rip),%rdi
lea    0xe47(%rip),%rax
cmovbe %rax,%rdi
xorps  %xmm1,%xmm1
ucomiss %xmm1,%xmm0
cmovb  %rax,%rdi
call   1030 <puts@plt>
xor    %eax,%eax
pop    %rcx
ret

LLVM IR (-O0):
@.str = [3 x i8] c"%f\00"
@.str.1 = [3 x i8] c"A\0A\00"
@.str.2 = [3 x i8] c"B\0A\00"
@.str.3 = [3 x i8] c"C\0A\00"
@.str.4 = [3 x i8] c"D\0A\00"
@.str.5 = [3 x i8] c"F\0A\00"
@.str.6 = [14 x i8] c"Out of Range\0A\00"
define i32 @main() {
%1 = alloca i32
%2 = alloca float
store i32 0, i32* %1
%3 = call i32 @scanf(i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str, i64 0, i64 0), float* %2)
%4 = load float, float* %2
%5 = fcmp oge float %4, 8.000000e+01
br i1 %5, label %6, label %11
6: ; preds = %0
%7 = load float, float* %2
%8 = fcmp ole float %7, 1.000000e+02
br i1 %8, label %9, label %11
9: ; preds = %6
%10 = call i32 @printf(i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str.1, i64 0, i64 0))
br label %49
11: ; preds = %6, %0
%12 = load float, float* %2
%13 = fcmp oge float %12, 7.000000e+01
br i1 %13, label %14, label %19
14: ; preds = %11
%15 = load float, float* %2
%16 = fcmp olt float %15, 8.000000e+01
br i1 %16, label %17, label %19
17: ; preds = %14
%18 = call i32 @printf(i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str.2, i64 0, i64 0))
br label %48
19: ; preds = %14, %11
%20 = load float, float* %2
%21 = fcmp oge float %20, 6.000000e+01
br i1 %21, label %22, label %27
22: ; preds = %19
%23 = load float, float* %2
%24 = fcmp olt float %23, 7.000000e+01
br i1 %24, label %25, label %27
25: ; preds = %22
%26 = call i32 @printf(i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str.3, i64 0, i64 0))
br label %47
27: ; preds = %22, %19
%28 = load float, float* %2
%29 = fcmp oge float %28, 5.000000e+01
br i1 %29, label %30, label %35
30: ; preds = %27
%31 = load float, float* %2
%32 = fcmp olt float %31, 6.000000e+01
br i1 %32, label %33, label %35
33: ; preds = %30
%34 = call i32 @printf(i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str.4, i64 0, i64 0))
br label %46
35: ; preds = %30, %27
%36 = load float, float* %2
%37 = fcmp oge float %36, 0.000000e+00
br i1 %37, label %38, label %43
38: ; preds = %35
%39 = load float, float* %2
%40 = fcmp olt float %39, 5.000000e+01
br i1 %40, label %41, label %43
41: ; preds = %38
%42 = call i32 @printf(i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str.5, i64 0, i64 0))
br label %45
43: ; preds = %38, %35
%44 = call i32 @printf(i8* getelementptr inbounds ([14 x i8], [14 x i8]* @.str.6, i64 0, i64 0))
br label %45
45: ; preds = %43, %41
br label %46
46: ; preds = %45, %33
br label %47
47: ; preds = %46, %25
br label %48
48: ; preds = %47, %17
br label %49
49: ; preds = %48, %9
%50 = load i32, i32* %1
ret i32 %50
}

LLVM IR (-O2):
@.str = [3 x i8] c"%f\00"
@str = [13 x i8] c"Out of Range\00"
@str.7 = [2 x i8] c"F\00"
@str.8 = [2 x i8] c"D\00"
@str.9 = [2 x i8] c"C\00"
@str.10 = [2 x i8] c"B\00"
@str.11 = [2 x i8] c"A\00"
define i32 @main() {
%1 = alloca float
%2 = bitcast float* %1 to i8*
%3 = call i32 @scanf(i8* getelementptr inbounds ([3 x i8], [3 x i8]* @.str, i64 0, i64 0), float* %1)
%4 = load float, float* %1
%5 = fcmp oge float %4, 8.000000e+01
%6 = fcmp ole float %4, 1.000000e+02
%7 = and i1 %5, %6
br i1 %7, label %25, label %8
8: ; preds = %0
%9 = fcmp oge float %4, 7.000000e+01
%10 = fcmp olt float %4, 8.000000e+01
%11 = and i1 %9, %10
br i1 %11, label %25, label %12
12: ; preds = %8
%13 = fcmp oge float %4, 6.000000e+01
%14 = fcmp olt float %4, 7.000000e+01
%15 = and i1 %13, %14
br i1 %15, label %25, label %16
16: ; preds = %12
%17 = fcmp oge float %4, 5.000000e+01
%18 = fcmp olt float %4, 6.000000e+01
%19 = and i1 %17, %18
br i1 %19, label %25, label %20
20: ; preds = %16
%21 = fcmp oge float %4, 0.000000e+00
%22 = fcmp olt float %4, 5.000000e+01
%23 = and i1 %21, %22
%24 = select i1 %23, i8* getelementptr inbounds ([2 x i8], [2 x i8]* @str.7, i64 0, i64 0), i8* getelementptr inbounds ([13 x i8], [13 x i8]* @str, i64 0, i64 0)
br label %25
25: ; preds = %20, %16, %12, %8, %0
%26 = phi i8* [ getelementptr inbounds ([2 x i8], [2 x i8]* @str.11, i64 0, i64 0), %0 ], [ getelementptr inbounds ([2 x i8], [2 x i8]* @str.10, i64 0, i64 0), %8 ], [ getelementptr inbounds ([2 x i8], [2 x i8]* @str.9, i64 0, i64 0), %12 ], [ getelementptr inbounds ([2 x i8], [2 x i8]* @str.8, i64 0, i64 0), %16 ], [ %24, %20 ]
%27 = call i32 @puts(i8* dereferenceable(1) %26)
ret i32 0
}