const char *mcuio_packet_type_to_str(int t) {
  switch (t & 0x07) {
  case 0:
    return "rdb";
  case 1:
    return "wrb";
  case 2:
    return "rdw";
  case 3:
    return "wrw";
  case 4:
    return "rddw";
  case 5:
    return "wrdw";
  case 6:
    return "rdq";
  case 7:
    return "wrq";
  }
  return "unknown";
}


x86 assembly (clang, -O0):
<mcuio_packet_type_to_str>:
push   %rbp
mov    %rsp,%rbp
mov    %edi,-0xc(%rbp)
mov    -0xc(%rbp),%eax
and    $0x7,%eax
mov    %rax,-0x18(%rbp)
sub    $0x7,%eax
ja     11ae <mcuio_packet_type_to_str+0xae>
mov    -0x18(%rbp),%rax
lea    0xedb(%rip),%rcx
movslq (%rcx,%rax,4),%rax
add    %rcx,%rax
jmp    *%rax
lea    0xeeb(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    11b9 <mcuio_packet_type_to_str+0xb9>
lea    0xedf(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    11b9 <mcuio_packet_type_to_str+0xb9>
lea    0xedd(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    11b9 <mcuio_packet_type_to_str+0xb9>
lea    0xec3(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    11b9 <mcuio_packet_type_to_str+0xb9>
lea    0xeb7(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    11b9 <mcuio_packet_type_to_str+0xb9>
lea    0xeac(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    11b9 <mcuio_packet_type_to_str+0xb9>
lea    0xea1(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    11b9 <mcuio_packet_type_to_str+0xb9>
lea    0xe95(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    11b9 <mcuio_packet_type_to_str+0xb9>
lea    0xe89(%rip),%rax
mov    %rax,-0x8(%rbp)
mov    -0x8(%rbp),%rax
pop    %rbp
ret

x86 assembly (clang, -O2):
<mcuio_packet_type_to_str>:
and    $0x7,%edi
lea    0xf16(%rip),%rcx
movslq (%rcx,%rdi,4),%rax
add    %rcx,%rax
ret

LLVM IR (-O0):
@.str = [4 x i8] c"rdb\00"
@.str.1 = [4 x i8] c"wrb\00"
@.str.2 = [4 x i8] c"rdw\00"
@.str.3 = [4 x i8] c"wrw\00"
@.str.4 = [5 x i8] c"rddw\00"
@.str.5 = [5 x i8] c"wrdw\00"
@.str.6 = [4 x i8] c"rdq\00"
@.str.7 = [4 x i8] c"wrq\00"
@.str.8 = [8 x i8] c"unknown\00"
define i8* @mcuio_packet_type_to_str(i32 %0) {
%2 = alloca i8*
%3 = alloca i32
store i32 %0, i32* %3
%4 = load i32, i32* %3
%5 = and i32 %4, 7
switch i32 %5, label %14 [
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
]
6: ; preds = %1
store i8* getelementptr inbounds ([4 x i8], [4 x i8]* @.str, i64 0, i64 0), i8** %2
br label %15
7: ; preds = %1
store i8* getelementptr inbounds ([4 x i8], [4 x i8]* @.str.1, i64 0, i64 0), i8** %2
br label %15
8: ; preds = %1
store i8* getelementptr inbounds ([4 x i8], [4 x i8]* @.str.2, i64 0, i64 0), i8** %2
br label %15
9: ; preds = %1
store i8* getelementptr inbounds ([4 x i8], [4 x i8]* @.str.3, i64 0, i64 0), i8** %2
br label %15
10: ; preds = %1
store i8* getelementptr inbounds ([5 x i8], [5 x i8]* @.str.4, i64 0, i64 0), i8** %2
br label %15
11: ; preds = %1
store i8* getelementptr inbounds ([5 x i8], [5 x i8]* @.str.5, i64 0, i64 0), i8** %2
br label %15
12: ; preds = %1
store i8* getelementptr inbounds ([4 x i8], [4 x i8]* @.str.6, i64 0, i64 0), i8** %2
br label %15
13: ; preds = %1
store i8* getelementptr inbounds ([4 x i8], [4 x i8]* @.str.7, i64 0, i64 0), i8** %2
br label %15
14: ; preds = %1
store i8* getelementptr inbounds ([8 x i8], [8 x i8]* @.str.8, i64 0, i64 0), i8** %2
br label %15
15: ; preds = %14, %13, %12, %11, %10, %9, %8, %7, %6
%16 = load i8*, i8** %2
ret i8* %16
}

LLVM IR (-O2):
@.str = [4 x i8] c"rdb\00"
@.str.1 = [4 x i8] c"wrb\00"
@.str.2 = [4 x i8] c"rdw\00"
@.str.3 = [4 x i8] c"wrw\00"
@.str.4 = [5 x i8] c"rddw\00"
@.str.5 = [5 x i8] c"wrdw\00"
@.str.6 = [4 x i8] c"rdq\00"
@.str.7 = [4 x i8] c"wrq\00"
@reltable.mcuio_packet_type_to_str = [8 x i32] [i32 trunc (i64 sub (i64 ptrtoint ([4 x i8]* @.str to i64), i64 ptrtoint ([8 x i32]* @reltable.mcuio_packet_type_to_str to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([4 x i8]* @.str.1 to i64), i64 ptrtoint ([8 x i32]* @reltable.mcuio_packet_type_to_str to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([4 x i8]* @.str.2 to i64), i64 ptrtoint ([8 x i32]* @reltable.mcuio_packet_type_to_str to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([4 x i8]* @.str.3 to i64), i64 ptrtoint ([8 x i32]* @reltable.mcuio_packet_type_to_str to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([5 x i8]* @.str.4 to i64), i64 ptrtoint ([8 x i32]* @reltable.mcuio_packet_type_to_str to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([5 x i8]* @.str.5 to i64), i64 ptrtoint ([8 x i32]* @reltable.mcuio_packet_type_to_str to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([4 x i8]* @.str.6 to i64), i64 ptrtoint ([8 x i32]* @reltable.mcuio_packet_type_to_str to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([4 x i8]* @.str.7 to i64), i64 ptrtoint ([8 x i32]* @reltable.mcuio_packet_type_to_str to i64)) to i32)]
define i8* @mcuio_packet_type_to_str(i32 %0) {
%2 = and i32 %0, 7
%3 = zext i32 %2 to i64
%4 = shl i64 %3, 2
%5 = call i8* @llvm.load.relative.i64(i8* bitcast ([8 x i32]* @reltable.mcuio_packet_type_to_str to i8*), i64 %4)
ret i8* %5
}