int char_to_bitmap(char x) {
  switch (x & ~32) {
  case 'A':
    return 1;
  case 'C':
    return 2;
  case 'G':
    return 4;
  case 'T':
    return 8;
  case 'U':
    return 8;
  case 'S':
    return 6;
  case 'W':
    return 9;
  case 'R':
    return 5;
  case 'Y':
    return 10;
  case 'K':
    return 12;
  case 'M':
    return 3;
  case 'B':
    return 14;
  case 'D':
    return 13;
  case 'H':
    return 11;
  case 'V':
    return 7;
  case 'N':
    return 15;
  default:
    return 0;
  }
}


x86 assembly (clang, -O0):
<char_to_bitmap>:
push   %rbp
mov    %rsp,%rbp
mov    %dil,%al
mov    %al,-0x5(%rbp)
movsbl -0x5(%rbp),%eax
and    $0xffffffdf,%eax
add    $0xffffffbf,%eax
mov    %eax,%ecx
mov    %rcx,-0x10(%rbp)
sub    $0x18,%eax
ja     11f7 <char_to_bitmap+0xf7>
mov    -0x10(%rbp),%rax
lea    0xed2(%rip),%rcx
movslq (%rcx,%rax,4),%rax
add    %rcx,%rax
jmp    *%rax
movl   $0x1,-0x4(%rbp)
jmp    11fe <char_to_bitmap+0xfe>
movl   $0x2,-0x4(%rbp)
jmp    11fe <char_to_bitmap+0xfe>
movl   $0x4,-0x4(%rbp)
jmp    11fe <char_to_bitmap+0xfe>
movl   $0x8,-0x4(%rbp)
jmp    11fe <char_to_bitmap+0xfe>
movl   $0x8,-0x4(%rbp)
jmp    11fe <char_to_bitmap+0xfe>
movl   $0x6,-0x4(%rbp)
jmp    11fe <char_to_bitmap+0xfe>
movl   $0x9,-0x4(%rbp)
jmp    11fe <char_to_bitmap+0xfe>
movl   $0x5,-0x4(%rbp)
jmp    11fe <char_to_bitmap+0xfe>
movl   $0xa,-0x4(%rbp)
jmp    11fe <char_to_bitmap+0xfe>
movl   $0xc,-0x4(%rbp)
jmp    11fe <char_to_bitmap+0xfe>
movl   $0x3,-0x4(%rbp)
jmp    11fe <char_to_bitmap+0xfe>
movl   $0xe,-0x4(%rbp)
jmp    11fe <char_to_bitmap+0xfe>
movl   $0xd,-0x4(%rbp)
jmp    11fe <char_to_bitmap+0xfe>
movl   $0xb,-0x4(%rbp)
jmp    11fe <char_to_bitmap+0xfe>
movl   $0x7,-0x4(%rbp)
jmp    11fe <char_to_bitmap+0xfe>
movl   $0xf,-0x4(%rbp)
jmp    11fe <char_to_bitmap+0xfe>
movl   $0x0,-0x4(%rbp)
mov    -0x4(%rbp),%eax
pop    %rbp
ret

x86 assembly (clang, -O2):
<char_to_bitmap>:
and    $0xdf,%dil
movsbl %dil,%ecx
add    $0xffffffbf,%ecx
xor    %eax,%eax
cmp    $0x18,%ecx
ja     111f <char_to_bitmap+0x1f>
movslq %ecx,%rax
lea    0xee4(%rip),%rcx
mov    (%rcx,%rax,4),%eax
ret

LLVM IR (-O0):
define i32 @char_to_bitmap(i8 signext %0) {
%2 = alloca i32
%3 = alloca i8
store i8 %0, i8* %3
%4 = load i8, i8* %3
%5 = sext i8 %4 to i32
%6 = and i32 %5, -33
switch i32 %6, label %23 [
i32 65, label %7
i32 67, label %8
i32 71, label %9
i32 84, label %10
i32 85, label %11
i32 83, label %12
i32 87, label %13
i32 82, label %14
i32 89, label %15
i32 75, label %16
i32 77, label %17
i32 66, label %18
i32 68, label %19
i32 72, label %20
i32 86, label %21
i32 78, label %22
]
7: ; preds = %1
store i32 1, i32* %2
br label %24
8: ; preds = %1
store i32 2, i32* %2
br label %24
9: ; preds = %1
store i32 4, i32* %2
br label %24
10: ; preds = %1
store i32 8, i32* %2
br label %24
11: ; preds = %1
store i32 8, i32* %2
br label %24
12: ; preds = %1
store i32 6, i32* %2
br label %24
13: ; preds = %1
store i32 9, i32* %2
br label %24
14: ; preds = %1
store i32 5, i32* %2
br label %24
15: ; preds = %1
store i32 10, i32* %2
br label %24
16: ; preds = %1
store i32 12, i32* %2
br label %24
17: ; preds = %1
store i32 3, i32* %2
br label %24
18: ; preds = %1
store i32 14, i32* %2
br label %24
19: ; preds = %1
store i32 13, i32* %2
br label %24
20: ; preds = %1
store i32 11, i32* %2
br label %24
21: ; preds = %1
store i32 7, i32* %2
br label %24
22: ; preds = %1
store i32 15, i32* %2
br label %24
23: ; preds = %1
store i32 0, i32* %2
br label %24
24: ; preds = %23, %22, %21, %20, %19, %18, %17, %16, %15, %14, %13, %12, %11, %10, %9, %8, %7
%25 = load i32, i32* %2
ret i32 %25
}

LLVM IR (-O2):
@switch.table.char_to_bitmap = [25 x i32] [i32 1, i32 14, i32 2, i32 13, i32 0, i32 0, i32 4, i32 11, i32 0, i32 0, i32 12, i32 0, i32 3, i32 15, i32 0, i32 0, i32 0, i32 5, i32 6, i32 8, i32 8, i32 7, i32 9, i32 0, i32 10]
define i32 @char_to_bitmap(i8 signext %0) {
%2 = and i8 %0, -33
%3 = sext i8 %2 to i32
%4 = add nsw i32 %3, -65
%5 = icmp ult i32 %4, 25
br i1 %5, label %6, label %10
6: ; preds = %1
%7 = sext i32 %4 to i64
%8 = getelementptr inbounds [25 x i32], [25 x i32]* @switch.table.char_to_bitmap, i64 0, i64 %7
%9 = load i32, i32* %8
br label %10
10: ; preds = %1, %6
%11 = phi i32 [ %9, %6 ], [ 0, %1 ]
ret i32 %11
}