const char *scalar_opcode(unsigned opcode) {
  switch (opcode) {
  case 0:
    return "NOP";
  case 1:
    return "MOV";
  case 2:
    return "RCP";
  case 3:
    return "RCC";
  case 4:
    return "RSQ";
  case 5:
    return "EXP";
  case 6:
    return "LOG";
  case 7:
    return "LIT";
  case 9:
    return "BRA";
  case 11:
    return "CAL";
  case 12:
    return "RET";
  case 13:
    return "LG2";
  case 14:
    return "EX2";
  case 15:
    return "SIN";
  case 16:
    return "COS";
  case 19:
    return "PUSHA";
  case 20:
    return "POPA";
  case 17:
    return "OPCODE-17";
  case 18:
    return "OPCODE-18";
  case 21:
    return "OPCODE-21";
  case 22:
    return "OPCODE-22";
  case 23:
    return "OPCODE-23";
  case 24:
    return "OPCODE-24";
  case 25:
    return "OPCODE-25";
  case 26:
    return "OPCODE-26";
  case 27:
    return "OPCODE-27";
  case 28:
    return "OPCODE-28";
  case 29:
    return "OPCODE-29";
  case 30:
    return "OPCODE-30";
  case 31:
    return "OPCODE-31";
  default:
    break;
  }
  return "INVALID!";
}


x86 assembly (clang, -O0):
<scalar_opcode>:
push   %rbp
mov    %rsp,%rbp
mov    %edi,-0xc(%rbp)
mov    -0xc(%rbp),%eax
mov    %rax,-0x18(%rbp)
sub    $0x1f,%rax
ja     130c <scalar_opcode+0x20c>
mov    -0x18(%rbp),%rax
lea    0xedd(%rip),%rcx
movslq (%rcx,%rax,4),%rax
add    %rcx,%rax
jmp    *%rax
lea    0xf4d(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    131c <scalar_opcode+0x21c>
lea    0xf41(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    131c <scalar_opcode+0x21c>
lea    0xf35(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    131c <scalar_opcode+0x21c>
lea    0xf29(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    131c <scalar_opcode+0x21c>
lea    0xf1d(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    131c <scalar_opcode+0x21c>
lea    0xf11(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    131c <scalar_opcode+0x21c>
lea    0xf05(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    131c <scalar_opcode+0x21c>
lea    0xef9(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    131c <scalar_opcode+0x21c>
lea    0xeed(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    131c <scalar_opcode+0x21c>
lea    0xee1(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    131c <scalar_opcode+0x21c>
lea    0xed5(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    131c <scalar_opcode+0x21c>
lea    0xec9(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    131c <scalar_opcode+0x21c>
lea    0xebd(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    131c <scalar_opcode+0x21c>
lea    0xeb1(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    131c <scalar_opcode+0x21c>
lea    0xea5(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    131c <scalar_opcode+0x21c>
lea    0xe99(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    131c <scalar_opcode+0x21c>
lea    0xe8f(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    131c <scalar_opcode+0x21c>
lea    0xe84(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    131c <scalar_opcode+0x21c>
lea    0xe7e(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    131c <scalar_opcode+0x21c>
lea    0xe78(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    131c <scalar_opcode+0x21c>
lea    0xe72(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    131c <scalar_opcode+0x21c>
lea    0xe6c(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    131c <scalar_opcode+0x21c>
lea    0xe66(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    131c <scalar_opcode+0x21c>
lea    0xe60(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    131c <scalar_opcode+0x21c>
lea    0xe5a(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    131c <scalar_opcode+0x21c>
lea    0xe54(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    131c <scalar_opcode+0x21c>
lea    0xe4e(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    131c <scalar_opcode+0x21c>
lea    0xe48(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    131c <scalar_opcode+0x21c>
lea    0xe42(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    131c <scalar_opcode+0x21c>
lea    0xe3c(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    131c <scalar_opcode+0x21c>
jmp    1311 <scalar_opcode+0x211>
lea    0xe31(%rip),%rax
mov    %rax,-0x8(%rbp)
mov    -0x8(%rbp),%rax
pop    %rbp
ret

x86 assembly (clang, -O2):
<scalar_opcode>:
cmp    $0x1f,%edi
ja     1117 <scalar_opcode+0x17>
movslq %edi,%rax
lea    0xfc5(%rip),%rcx
movslq (%rcx,%rax,4),%rax
add    %rcx,%rax
ret
lea    0xfab(%rip),%rax
ret

LLVM IR (-O0):
@.str = [4 x i8] c"NOP\00"
@.str.1 = [4 x i8] c"MOV\00"
@.str.2 = [4 x i8] c"RCP\00"
@.str.3 = [4 x i8] c"RCC\00"
@.str.4 = [4 x i8] c"RSQ\00"
@.str.5 = [4 x i8] c"EXP\00"
@.str.6 = [4 x i8] c"LOG\00"
@.str.7 = [4 x i8] c"LIT\00"
@.str.8 = [4 x i8] c"BRA\00"
@.str.9 = [4 x i8] c"CAL\00"
@.str.10 = [4 x i8] c"RET\00"
@.str.11 = [4 x i8] c"LG2\00"
@.str.12 = [4 x i8] c"EX2\00"
@.str.13 = [4 x i8] c"SIN\00"
@.str.14 = [4 x i8] c"COS\00"
@.str.15 = [6 x i8] c"PUSHA\00"
@.str.16 = [5 x i8] c"POPA\00"
@.str.17 = [10 x i8] c"OPCODE-17\00"
@.str.18 = [10 x i8] c"OPCODE-18\00"
@.str.19 = [10 x i8] c"OPCODE-21\00"
@.str.20 = [10 x i8] c"OPCODE-22\00"
@.str.21 = [10 x i8] c"OPCODE-23\00"
@.str.22 = [10 x i8] c"OPCODE-24\00"
@.str.23 = [10 x i8] c"OPCODE-25\00"
@.str.24 = [10 x i8] c"OPCODE-26\00"
@.str.25 = [10 x i8] c"OPCODE-27\00"
@.str.26 = [10 x i8] c"OPCODE-28\00"
@.str.27 = [10 x i8] c"OPCODE-29\00"
@.str.28 = [10 x i8] c"OPCODE-30\00"
@.str.29 = [10 x i8] c"OPCODE-31\00"
@.str.30 = [9 x i8] c"INVALID!\00"
define i8* @scalar_opcode(i32 %0) {
%2 = alloca i8*
%3 = alloca i32
store i32 %0, i32* %3
%4 = load i32, i32* %3
switch i32 %4, label %35 [
i32 0, label %5
i32 1, label %6
i32 2, label %7
i32 3, label %8
i32 4, label %9
i32 5, label %10
i32 6, label %11
i32 7, label %12
i32 9, label %13
i32 11, label %14
i32 12, label %15
i32 13, label %16
i32 14, label %17
i32 15, label %18
i32 16, label %19
i32 19, label %20
i32 20, label %21
i32 17, label %22
i32 18, label %23
i32 21, label %24
i32 22, label %25
i32 23, label %26
i32 24, label %27
i32 25, label %28
i32 26, label %29
i32 27, label %30
i32 28, label %31
i32 29, label %32
i32 30, label %33
i32 31, label %34
]
5: ; preds = %1
store i8* getelementptr inbounds ([4 x i8], [4 x i8]* @.str, i64 0, i64 0), i8** %2
br label %37
6: ; preds = %1
store i8* getelementptr inbounds ([4 x i8], [4 x i8]* @.str.1, i64 0, i64 0), i8** %2
br label %37
7: ; preds = %1
store i8* getelementptr inbounds ([4 x i8], [4 x i8]* @.str.2, i64 0, i64 0), i8** %2
br label %37
8: ; preds = %1
store i8* getelementptr inbounds ([4 x i8], [4 x i8]* @.str.3, i64 0, i64 0), i8** %2
br label %37
9: ; preds = %1
store i8* getelementptr inbounds ([4 x i8], [4 x i8]* @.str.4, i64 0, i64 0), i8** %2
br label %37
10: ; preds = %1
store i8* getelementptr inbounds ([4 x i8], [4 x i8]* @.str.5, i64 0, i64 0), i8** %2
br label %37
11: ; preds = %1
store i8* getelementptr inbounds ([4 x i8], [4 x i8]* @.str.6, i64 0, i64 0), i8** %2
br label %37
12: ; preds = %1
store i8* getelementptr inbounds ([4 x i8], [4 x i8]* @.str.7, i64 0, i64 0), i8** %2
br label %37
13: ; preds = %1
store i8* getelementptr inbounds ([4 x i8], [4 x i8]* @.str.8, i64 0, i64 0), i8** %2
br label %37
14: ; preds = %1
store i8* getelementptr inbounds ([4 x i8], [4 x i8]* @.str.9, i64 0, i64 0), i8** %2
br label %37
15: ; preds = %1
store i8* getelementptr inbounds ([4 x i8], [4 x i8]* @.str.10, i64 0, i64 0), i8** %2
br label %37
16: ; preds = %1
store i8* getelementptr inbounds ([4 x i8], [4 x i8]* @.str.11, i64 0, i64 0), i8** %2
br label %37
17: ; preds = %1
store i8* getelementptr inbounds ([4 x i8], [4 x i8]* @.str.12, i64 0, i64 0), i8** %2
br label %37
18: ; preds = %1
store i8* getelementptr inbounds ([4 x i8], [4 x i8]* @.str.13, i64 0, i64 0), i8** %2
br label %37
19: ; preds = %1
store i8* getelementptr inbounds ([4 x i8], [4 x i8]* @.str.14, i64 0, i64 0), i8** %2
br label %37
20: ; preds = %1
store i8* getelementptr inbounds ([6 x i8], [6 x i8]* @.str.15, i64 0, i64 0), i8** %2
br label %37
21: ; preds = %1
store i8* getelementptr inbounds ([5 x i8], [5 x i8]* @.str.16, i64 0, i64 0), i8** %2
br label %37
22: ; preds = %1
store i8* getelementptr inbounds ([10 x i8], [10 x i8]* @.str.17, i64 0, i64 0), i8** %2
br label %37
23: ; preds = %1
store i8* getelementptr inbounds ([10 x i8], [10 x i8]* @.str.18, i64 0, i64 0), i8** %2
br label %37
24: ; preds = %1
store i8* getelementptr inbounds ([10 x i8], [10 x i8]* @.str.19, i64 0, i64 0), i8** %2
br label %37
25: ; preds = %1
store i8* getelementptr inbounds ([10 x i8], [10 x i8]* @.str.20, i64 0, i64 0), i8** %2
br label %37
26: ; preds = %1
store i8* getelementptr inbounds ([10 x i8], [10 x i8]* @.str.21, i64 0, i64 0), i8** %2
br label %37
27: ; preds = %1
store i8* getelementptr inbounds ([10 x i8], [10 x i8]* @.str.22, i64 0, i64 0), i8** %2
br label %37
28: ; preds = %1
store i8* getelementptr inbounds ([10 x i8], [10 x i8]* @.str.23, i64 0, i64 0), i8** %2
br label %37
29: ; preds = %1
store i8* getelementptr inbounds ([10 x i8], [10 x i8]* @.str.24, i64 0, i64 0), i8** %2
br label %37
30: ; preds = %1
store i8* getelementptr inbounds ([10 x i8], [10 x i8]* @.str.25, i64 0, i64 0), i8** %2
br label %37
31: ; preds = %1
store i8* getelementptr inbounds ([10 x i8], [10 x i8]* @.str.26, i64 0, i64 0), i8** %2
br label %37
32: ; preds = %1
store i8* getelementptr inbounds ([10 x i8], [10 x i8]* @.str.27, i64 0, i64 0), i8** %2
br label %37
33: ; preds = %1
store i8* getelementptr inbounds ([10 x i8], [10 x i8]* @.str.28, i64 0, i64 0), i8** %2
br label %37
34: ; preds = %1
store i8* getelementptr inbounds ([10 x i8], [10 x i8]* @.str.29, i64 0, i64 0), i8** %2
br label %37
35: ; preds = %1
br label %36
36: ; preds = %35
store i8* getelementptr inbounds ([9 x i8], [9 x i8]* @.str.30, i64 0, i64 0), i8** %2
br label %37
37: ; preds = %36, %34, %33, %32, %31, %30, %29, %28, %27, %26, %25, %24, %23, %22, %21, %20, %19, %18, %17, %16, %15, %14, %13, %12, %11, %10, %9, %8, %7, %6, %5
%38 = load i8*, i8** %2
ret i8* %38
}

LLVM IR (-O2):
@.str = [4 x i8] c"NOP\00"
@.str.1 = [4 x i8] c"MOV\00"
@.str.2 = [4 x i8] c"RCP\00"
@.str.3 = [4 x i8] c"RCC\00"
@.str.4 = [4 x i8] c"RSQ\00"
@.str.5 = [4 x i8] c"EXP\00"
@.str.6 = [4 x i8] c"LOG\00"
@.str.7 = [4 x i8] c"LIT\00"
@.str.8 = [4 x i8] c"BRA\00"
@.str.9 = [4 x i8] c"CAL\00"
@.str.10 = [4 x i8] c"RET\00"
@.str.11 = [4 x i8] c"LG2\00"
@.str.12 = [4 x i8] c"EX2\00"
@.str.13 = [4 x i8] c"SIN\00"
@.str.14 = [4 x i8] c"COS\00"
@.str.15 = [6 x i8] c"PUSHA\00"
@.str.16 = [5 x i8] c"POPA\00"
@.str.17 = [10 x i8] c"OPCODE-17\00"
@.str.18 = [10 x i8] c"OPCODE-18\00"
@.str.19 = [10 x i8] c"OPCODE-21\00"
@.str.20 = [10 x i8] c"OPCODE-22\00"
@.str.21 = [10 x i8] c"OPCODE-23\00"
@.str.22 = [10 x i8] c"OPCODE-24\00"
@.str.23 = [10 x i8] c"OPCODE-25\00"
@.str.24 = [10 x i8] c"OPCODE-26\00"
@.str.25 = [10 x i8] c"OPCODE-27\00"
@.str.26 = [10 x i8] c"OPCODE-28\00"
@.str.27 = [10 x i8] c"OPCODE-29\00"
@.str.28 = [10 x i8] c"OPCODE-30\00"
@.str.29 = [10 x i8] c"OPCODE-31\00"
@.str.30 = [9 x i8] c"INVALID!\00"
@reltable.scalar_opcode = [32 x i32] [i32 trunc (i64 sub (i64 ptrtoint ([4 x i8]* @.str to i64), i64 ptrtoint ([32 x i32]* @reltable.scalar_opcode to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([4 x i8]* @.str.1 to i64), i64 ptrtoint ([32 x i32]* @reltable.scalar_opcode to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([4 x i8]* @.str.2 to i64), i64 ptrtoint ([32 x i32]* @reltable.scalar_opcode to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([4 x i8]* @.str.3 to i64), i64 ptrtoint ([32 x i32]* @reltable.scalar_opcode to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([4 x i8]* @.str.4 to i64), i64 ptrtoint ([32 x i32]* @reltable.scalar_opcode to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([4 x i8]* @.str.5 to i64), i64 ptrtoint ([32 x i32]* @reltable.scalar_opcode to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([4 x i8]* @.str.6 to i64), i64 ptrtoint ([32 x i32]* @reltable.scalar_opcode to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([4 x i8]* @.str.7 to i64), i64 ptrtoint ([32 x i32]* @reltable.scalar_opcode to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([9 x i8]* @.str.30 to i64), i64 ptrtoint ([32 x i32]* @reltable.scalar_opcode to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([4 x i8]* @.str.8 to i64), i64 ptrtoint ([32 x i32]* @reltable.scalar_opcode to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([9 x i8]* @.str.30 to i64), i64 ptrtoint ([32 x i32]* @reltable.scalar_opcode to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([4 x i8]* @.str.9 to i64), i64 ptrtoint ([32 x i32]* @reltable.scalar_opcode to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([4 x i8]* @.str.10 to i64), i64 ptrtoint ([32 x i32]* @reltable.scalar_opcode to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([4 x i8]* @.str.11 to i64), i64 ptrtoint ([32 x i32]* @reltable.scalar_opcode to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([4 x i8]* @.str.12 to i64), i64 ptrtoint ([32 x i32]* @reltable.scalar_opcode to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([4 x i8]* @.str.13 to i64), i64 ptrtoint ([32 x i32]* @reltable.scalar_opcode to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([4 x i8]* @.str.14 to i64), i64 ptrtoint ([32 x i32]* @reltable.scalar_opcode to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([10 x i8]* @.str.17 to i64), i64 ptrtoint ([32 x i32]* @reltable.scalar_opcode to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([10 x i8]* @.str.18 to i64), i64 ptrtoint ([32 x i32]* @reltable.scalar_opcode to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([6 x i8]* @.str.15 to i64), i64 ptrtoint ([32 x i32]* @reltable.scalar_opcode to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([5 x i8]* @.str.16 to i64), i64 ptrtoint ([32 x i32]* @reltable.scalar_opcode to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([10 x i8]* @.str.19 to i64), i64 ptrtoint ([32 x i32]* @reltable.scalar_opcode to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([10 x i8]* @.str.20 to i64), i64 ptrtoint ([32 x i32]* @reltable.scalar_opcode to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([10 x i8]* @.str.21 to i64), i64 ptrtoint ([32 x i32]* @reltable.scalar_opcode to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([10 x i8]* @.str.22 to i64), i64 ptrtoint ([32 x i32]* @reltable.scalar_opcode to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([10 x i8]* @.str.23 to i64), i64 ptrtoint ([32 x i32]* @reltable.scalar_opcode to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([10 x i8]* @.str.24 to i64), i64 ptrtoint ([32 x i32]* @reltable.scalar_opcode to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([10 x i8]* @.str.25 to i64), i64 ptrtoint ([32 x i32]* @reltable.scalar_opcode to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([10 x i8]* @.str.26 to i64), i64 ptrtoint ([32 x i32]* @reltable.scalar_opcode to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([10 x i8]* @.str.27 to i64), i64 ptrtoint ([32 x i32]* @reltable.scalar_opcode to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([10 x i8]* @.str.28 to i64), i64 ptrtoint ([32 x i32]* @reltable.scalar_opcode to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([10 x i8]* @.str.29 to i64), i64 ptrtoint ([32 x i32]* @reltable.scalar_opcode to i64)) to i32)]
define i8* @scalar_opcode(i32 %0) {
%2 = icmp ult i32 %0, 32
br i1 %2, label %3, label %7
3: ; preds = %1
%4 = sext i32 %0 to i64
%5 = shl i64 %4, 2
%6 = call i8* @llvm.load.relative.i64(i8* bitcast ([32 x i32]* @reltable.scalar_opcode 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.30, i64 0, i64 0), %1 ]
ret i8* %8
}