char *getDeviceTypeFromCode(unsigned char c) {
  switch (c) {
  case 0x00:
    return "Other";
  case 0x01:
    return "Oil";
  case 0x02:
    return "Electricity";
  case 0x03:
    return "Gas";
  case 0x04:
    return "Heat";
  case 0x05:
    return "Steam";
  case 0x06:
    return "Warm Water";
  case 0x07:
    return "Water";
  case 0x08:
    return "Heat Cost Allocator";
  case 0x09:
    return "Compressed Air";
  case 0x0A:
    return "Cooling load meter";
  case 0x0B:
    return "Cooling load meter";
  case 0x0C:
    return "Heat";
  case 0x0D:
    return "Heat / Cooling load meter";
  case 0x0E:
    return "Bus / System component";
  case 0x0F:
    return "Unknown medium";
  case 0x15:
    return "Hot Water";
  case 0x16:
    return "Cold Water";
  case 0x17:
    return "Dual register Water meter";
  case 0x18:
    return "Pressure";
  case 0x19:
    return "A/D Converter";
  default:
    return "Reserved";
  }
  if (c >= 0x1A || (c >= 0x10 && c <= 0x14)) {
    return "Reserved";
  }
}


x86 assembly (clang, -O0):
<getDeviceTypeFromCode>:
push   %rbp
mov    %rsp,%rbp
mov    %dil,%al
mov    %al,-0x9(%rbp)
movzbl -0x9(%rbp),%eax
mov    %rax,-0x18(%rbp)
sub    $0x19,%rax
ja     1280 <getDeviceTypeFromCode+0x180>
mov    -0x18(%rbp),%rax
lea    0xed9(%rip),%rcx
movslq (%rcx,%rax,4),%rax
add    %rcx,%rax
jmp    *%rax
lea    0xf31(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    128b <getDeviceTypeFromCode+0x18b>
lea    0xf27(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    128b <getDeviceTypeFromCode+0x18b>
lea    0xf1b(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    128b <getDeviceTypeFromCode+0x18b>
lea    0xf17(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    128b <getDeviceTypeFromCode+0x18b>
lea    0xf0b(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    128b <getDeviceTypeFromCode+0x18b>
lea    0xf00(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    128b <getDeviceTypeFromCode+0x18b>
lea    0xef6(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    128b <getDeviceTypeFromCode+0x18b>
lea    0xf63(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    128b <getDeviceTypeFromCode+0x18b>
lea    0xee1(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    128b <getDeviceTypeFromCode+0x18b>
lea    0xee5(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    128b <getDeviceTypeFromCode+0x18b>
lea    0xeeb(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    128b <getDeviceTypeFromCode+0x18b>
lea    0xedb(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    128b <getDeviceTypeFromCode+0x18b>
lea    0xe8b(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    128b <getDeviceTypeFromCode+0x18b>
lea    0xeb4(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    128b <getDeviceTypeFromCode+0x18b>
lea    0xebe(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    128b <getDeviceTypeFromCode+0x18b>
lea    0xec5(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    128b <getDeviceTypeFromCode+0x18b>
lea    0xec4(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    128b <getDeviceTypeFromCode+0x18b>
lea    0xebe(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    128b <getDeviceTypeFromCode+0x18b>
lea    0xeb9(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    128b <getDeviceTypeFromCode+0x18b>
lea    0xec3(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    128b <getDeviceTypeFromCode+0x18b>
lea    0xebc(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    128b <getDeviceTypeFromCode+0x18b>
lea    0xeba(%rip),%rax
mov    %rax,-0x8(%rbp)
mov    -0x8(%rbp),%rax
pop    %rbp
ret

x86 assembly (clang, -O2):
<getDeviceTypeFromCode>:
cmp    $0x19,%dil
ja     1119 <getDeviceTypeFromCode+0x19>
movsbq %dil,%rax
lea    0xfd3(%rip),%rcx
movslq (%rcx,%rax,4),%rax
add    %rcx,%rax
ret
lea    0xfb9(%rip),%rax
ret

LLVM IR (-O0):
@.str = [6 x i8] c"Other\00"
@.str.1 = [4 x i8] c"Oil\00"
@.str.2 = [12 x i8] c"Electricity\00"
@.str.3 = [4 x i8] c"Gas\00"
@.str.4 = [5 x i8] c"Heat\00"
@.str.5 = [6 x i8] c"Steam\00"
@.str.6 = [11 x i8] c"Warm Water\00"
@.str.7 = [6 x i8] c"Water\00"
@.str.8 = [20 x i8] c"Heat Cost Allocator\00"
@.str.9 = [15 x i8] c"Compressed Air\00"
@.str.10 = [19 x i8] c"Cooling load meter\00"
@.str.11 = [26 x i8] c"Heat / Cooling load meter\00"
@.str.12 = [23 x i8] c"Bus / System component\00"
@.str.13 = [15 x i8] c"Unknown medium\00"
@.str.14 = [10 x i8] c"Hot Water\00"
@.str.15 = [11 x i8] c"Cold Water\00"
@.str.16 = [26 x i8] c"Dual register Water meter\00"
@.str.17 = [9 x i8] c"Pressure\00"
@.str.18 = [14 x i8] c"A/D Converter\00"
@.str.19 = [9 x i8] c"Reserved\00"
define i8* @getDeviceTypeFromCode(i8 zeroext %0) {
%2 = alloca i8*
%3 = alloca i8
store i8 %0, i8* %3
%4 = load i8, i8* %3
%5 = zext i8 %4 to i32
switch i32 %5, label %27 [
i32 0, label %6
i32 1, label %7
i32 2, label %8
i32 3, label %9
i32 4, label %10
i32 5, label %11
i32 6, label %12
i32 7, label %13
i32 8, label %14
i32 9, label %15
i32 10, label %16
i32 11, label %17
i32 12, label %18
i32 13, label %19
i32 14, label %20
i32 15, label %21
i32 21, label %22
i32 22, label %23
i32 23, label %24
i32 24, label %25
i32 25, label %26
]
6: ; preds = %1
store i8* getelementptr inbounds ([6 x i8], [6 x i8]* @.str, i64 0, i64 0), i8** %2
br label %28
7: ; preds = %1
store i8* getelementptr inbounds ([4 x i8], [4 x i8]* @.str.1, i64 0, i64 0), i8** %2
br label %28
8: ; preds = %1
store i8* getelementptr inbounds ([12 x i8], [12 x i8]* @.str.2, i64 0, i64 0), i8** %2
br label %28
9: ; preds = %1
store i8* getelementptr inbounds ([4 x i8], [4 x i8]* @.str.3, i64 0, i64 0), i8** %2
br label %28
10: ; preds = %1
store i8* getelementptr inbounds ([5 x i8], [5 x i8]* @.str.4, i64 0, i64 0), i8** %2
br label %28
11: ; preds = %1
store i8* getelementptr inbounds ([6 x i8], [6 x i8]* @.str.5, i64 0, i64 0), i8** %2
br label %28
12: ; preds = %1
store i8* getelementptr inbounds ([11 x i8], [11 x i8]* @.str.6, i64 0, i64 0), i8** %2
br label %28
13: ; preds = %1
store i8* getelementptr inbounds ([6 x i8], [6 x i8]* @.str.7, i64 0, i64 0), i8** %2
br label %28
14: ; preds = %1
store i8* getelementptr inbounds ([20 x i8], [20 x i8]* @.str.8, i64 0, i64 0), i8** %2
br label %28
15: ; preds = %1
store i8* getelementptr inbounds ([15 x i8], [15 x i8]* @.str.9, i64 0, i64 0), i8** %2
br label %28
16: ; preds = %1
store i8* getelementptr inbounds ([19 x i8], [19 x i8]* @.str.10, i64 0, i64 0), i8** %2
br label %28
17: ; preds = %1
store i8* getelementptr inbounds ([19 x i8], [19 x i8]* @.str.10, i64 0, i64 0), i8** %2
br label %28
18: ; preds = %1
store i8* getelementptr inbounds ([5 x i8], [5 x i8]* @.str.4, i64 0, i64 0), i8** %2
br label %28
19: ; preds = %1
store i8* getelementptr inbounds ([26 x i8], [26 x i8]* @.str.11, i64 0, i64 0), i8** %2
br label %28
20: ; preds = %1
store i8* getelementptr inbounds ([23 x i8], [23 x i8]* @.str.12, i64 0, i64 0), i8** %2
br label %28
21: ; preds = %1
store i8* getelementptr inbounds ([15 x i8], [15 x i8]* @.str.13, i64 0, i64 0), i8** %2
br label %28
22: ; preds = %1
store i8* getelementptr inbounds ([10 x i8], [10 x i8]* @.str.14, i64 0, i64 0), i8** %2
br label %28
23: ; preds = %1
store i8* getelementptr inbounds ([11 x i8], [11 x i8]* @.str.15, i64 0, i64 0), i8** %2
br label %28
24: ; preds = %1
store i8* getelementptr inbounds ([26 x i8], [26 x i8]* @.str.16, i64 0, i64 0), i8** %2
br label %28
25: ; preds = %1
store i8* getelementptr inbounds ([9 x i8], [9 x i8]* @.str.17, i64 0, i64 0), i8** %2
br label %28
26: ; preds = %1
store i8* getelementptr inbounds ([14 x i8], [14 x i8]* @.str.18, i64 0, i64 0), i8** %2
br label %28
27: ; preds = %1
store i8* getelementptr inbounds ([9 x i8], [9 x i8]* @.str.19, i64 0, i64 0), i8** %2
br label %28
28: ; preds = %27, %26, %25, %24, %23, %22, %21, %20, %19, %18, %17, %16, %15, %14, %13, %12, %11, %10, %9, %8, %7, %6
%29 = load i8*, i8** %2
ret i8* %29
}

LLVM IR (-O2):
@.str = [6 x i8] c"Other\00"
@.str.1 = [4 x i8] c"Oil\00"
@.str.2 = [12 x i8] c"Electricity\00"
@.str.3 = [4 x i8] c"Gas\00"
@.str.4 = [5 x i8] c"Heat\00"
@.str.5 = [6 x i8] c"Steam\00"
@.str.6 = [11 x i8] c"Warm Water\00"
@.str.7 = [6 x i8] c"Water\00"
@.str.8 = [20 x i8] c"Heat Cost Allocator\00"
@.str.9 = [15 x i8] c"Compressed Air\00"
@.str.10 = [19 x i8] c"Cooling load meter\00"
@.str.11 = [26 x i8] c"Heat / Cooling load meter\00"
@.str.12 = [23 x i8] c"Bus / System component\00"
@.str.13 = [15 x i8] c"Unknown medium\00"
@.str.14 = [10 x i8] c"Hot Water\00"
@.str.15 = [11 x i8] c"Cold Water\00"
@.str.16 = [26 x i8] c"Dual register Water meter\00"
@.str.17 = [9 x i8] c"Pressure\00"
@.str.18 = [14 x i8] c"A/D Converter\00"
@.str.19 = [9 x i8] c"Reserved\00"
@reltable.getDeviceTypeFromCode = [26 x i32] [i32 trunc (i64 sub (i64 ptrtoint ([6 x i8]* @.str to i64), i64 ptrtoint ([26 x i32]* @reltable.getDeviceTypeFromCode to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([4 x i8]* @.str.1 to i64), i64 ptrtoint ([26 x i32]* @reltable.getDeviceTypeFromCode to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([12 x i8]* @.str.2 to i64), i64 ptrtoint ([26 x i32]* @reltable.getDeviceTypeFromCode to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([4 x i8]* @.str.3 to i64), i64 ptrtoint ([26 x i32]* @reltable.getDeviceTypeFromCode to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([5 x i8]* @.str.4 to i64), i64 ptrtoint ([26 x i32]* @reltable.getDeviceTypeFromCode to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([6 x i8]* @.str.5 to i64), i64 ptrtoint ([26 x i32]* @reltable.getDeviceTypeFromCode to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([11 x i8]* @.str.6 to i64), i64 ptrtoint ([26 x i32]* @reltable.getDeviceTypeFromCode to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([6 x i8]* @.str.7 to i64), i64 ptrtoint ([26 x i32]* @reltable.getDeviceTypeFromCode to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([20 x i8]* @.str.8 to i64), i64 ptrtoint ([26 x i32]* @reltable.getDeviceTypeFromCode to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([15 x i8]* @.str.9 to i64), i64 ptrtoint ([26 x i32]* @reltable.getDeviceTypeFromCode to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([19 x i8]* @.str.10 to i64), i64 ptrtoint ([26 x i32]* @reltable.getDeviceTypeFromCode to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([19 x i8]* @.str.10 to i64), i64 ptrtoint ([26 x i32]* @reltable.getDeviceTypeFromCode to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([5 x i8]* @.str.4 to i64), i64 ptrtoint ([26 x i32]* @reltable.getDeviceTypeFromCode to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([26 x i8]* @.str.11 to i64), i64 ptrtoint ([26 x i32]* @reltable.getDeviceTypeFromCode to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([23 x i8]* @.str.12 to i64), i64 ptrtoint ([26 x i32]* @reltable.getDeviceTypeFromCode to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([15 x i8]* @.str.13 to i64), i64 ptrtoint ([26 x i32]* @reltable.getDeviceTypeFromCode to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([9 x i8]* @.str.19 to i64), i64 ptrtoint ([26 x i32]* @reltable.getDeviceTypeFromCode to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([9 x i8]* @.str.19 to i64), i64 ptrtoint ([26 x i32]* @reltable.getDeviceTypeFromCode to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([9 x i8]* @.str.19 to i64), i64 ptrtoint ([26 x i32]* @reltable.getDeviceTypeFromCode to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([9 x i8]* @.str.19 to i64), i64 ptrtoint ([26 x i32]* @reltable.getDeviceTypeFromCode to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([9 x i8]* @.str.19 to i64), i64 ptrtoint ([26 x i32]* @reltable.getDeviceTypeFromCode to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([10 x i8]* @.str.14 to i64), i64 ptrtoint ([26 x i32]* @reltable.getDeviceTypeFromCode to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([11 x i8]* @.str.15 to i64), i64 ptrtoint ([26 x i32]* @reltable.getDeviceTypeFromCode to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([26 x i8]* @.str.16 to i64), i64 ptrtoint ([26 x i32]* @reltable.getDeviceTypeFromCode to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([9 x i8]* @.str.17 to i64), i64 ptrtoint ([26 x i32]* @reltable.getDeviceTypeFromCode to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([14 x i8]* @.str.18 to i64), i64 ptrtoint ([26 x i32]* @reltable.getDeviceTypeFromCode to i64)) to i32)]
define i8* @getDeviceTypeFromCode(i8 zeroext %0) {
%2 = icmp ult i8 %0, 26
br i1 %2, label %3, label %7
3: ; preds = %1
%4 = sext i8 %0 to i64
%5 = shl i64 %4, 2
%6 = call i8* @llvm.load.relative.i64(i8* bitcast ([26 x i32]* @reltable.getDeviceTypeFromCode to i8*), i64 %5)
br label %7
7: ; preds = %1, %3
%8 = phi i8* [ %6, %3 ], [ getelementptr inbounds ([9 x i8], [9 x i8]* @.str.19, i64 0, i64 0), %1 ]
ret i8* %8
}