const char *stun_attr2str(int msg) {
  switch (msg) {
  case 0x0001:
    return "Mapped Address";
  case 0x0002:
    return "Response Address";
  case 0x0003:
    return "Change Request";
  case 0x0004:
    return "Source Address";
  case 0x0005:
    return "Changed Address";
  case 0x0006:
    return "Username";
  case 0x0007:
    return "Password";
  case 0x0008:
    return "Message Integrity";
  case 0x0009:
    return "Error Code";
  case 0x000a:
    return "Unknown Attributes";
  case 0x000b:
    return "Reflected From";
  }
  return "Non-RFC3489 Attribute";
}


x86 assembly (clang, -O0):
<stun_attr2str>:
push   %rbp
mov    %rsp,%rbp
mov    %edi,-0xc(%rbp)
mov    -0xc(%rbp),%eax
add    $0xffffffff,%eax
mov    %eax,%ecx
mov    %rcx,-0x18(%rbp)
sub    $0xa,%eax
ja     11e0 <stun_attr2str+0xe0>
mov    -0x18(%rbp),%rax
lea    0xed9(%rip),%rcx
movslq (%rcx,%rax,4),%rax
add    %rcx,%rax
jmp    *%rax
lea    0xef5(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    11eb <stun_attr2str+0xeb>
lea    0xef4(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    11eb <stun_attr2str+0xeb>
lea    0xef5(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    11eb <stun_attr2str+0xeb>
lea    0xef4(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    11eb <stun_attr2str+0xeb>
lea    0xef3(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    11eb <stun_attr2str+0xeb>
lea    0xef3(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    11eb <stun_attr2str+0xeb>
lea    0xeec(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    11eb <stun_attr2str+0xeb>
lea    0xee5(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    11eb <stun_attr2str+0xeb>
lea    0xee7(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    11eb <stun_attr2str+0xeb>
lea    0xee2(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    11eb <stun_attr2str+0xeb>
lea    0xee5(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    11eb <stun_attr2str+0xeb>
lea    0xee4(%rip),%rax
mov    %rax,-0x8(%rbp)
mov    -0x8(%rbp),%rax
pop    %rbp
ret

x86 assembly (clang, -O2):
<stun_attr2str>:
add    $0xffffffff,%edi
cmp    $0xa,%edi
ja     111a <stun_attr2str+0x1a>
movslq %edi,%rax
lea    0xfa6(%rip),%rcx
movslq (%rcx,%rax,4),%rax
add    %rcx,%rax
ret
lea    0xf7e(%rip),%rax
ret

LLVM IR (-O0):
@.str = [15 x i8] c"Mapped Address\00"
@.str.1 = [17 x i8] c"Response Address\00"
@.str.2 = [15 x i8] c"Change Request\00"
@.str.3 = [15 x i8] c"Source Address\00"
@.str.4 = [16 x i8] c"Changed Address\00"
@.str.5 = [9 x i8] c"Username\00"
@.str.6 = [9 x i8] c"Password\00"
@.str.7 = [18 x i8] c"Message Integrity\00"
@.str.8 = [11 x i8] c"Error Code\00"
@.str.9 = [19 x i8] c"Unknown Attributes\00"
@.str.10 = [15 x i8] c"Reflected From\00"
@.str.11 = [22 x i8] c"Non-RFC3489 Attribute\00"
define i8* @stun_attr2str(i32 %0) {
%2 = alloca i8*
%3 = alloca i32
store i32 %0, i32* %3
%4 = load i32, i32* %3
switch i32 %4, label %16 [
i32 1, label %5
i32 2, label %6
i32 3, label %7
i32 4, label %8
i32 5, label %9
i32 6, label %10
i32 7, label %11
i32 8, label %12
i32 9, label %13
i32 10, label %14
i32 11, label %15
]
5: ; preds = %1
store i8* getelementptr inbounds ([15 x i8], [15 x i8]* @.str, i64 0, i64 0), i8** %2
br label %17
6: ; preds = %1
store i8* getelementptr inbounds ([17 x i8], [17 x i8]* @.str.1, i64 0, i64 0), i8** %2
br label %17
7: ; preds = %1
store i8* getelementptr inbounds ([15 x i8], [15 x i8]* @.str.2, i64 0, i64 0), i8** %2
br label %17
8: ; preds = %1
store i8* getelementptr inbounds ([15 x i8], [15 x i8]* @.str.3, i64 0, i64 0), i8** %2
br label %17
9: ; preds = %1
store i8* getelementptr inbounds ([16 x i8], [16 x i8]* @.str.4, i64 0, i64 0), i8** %2
br label %17
10: ; preds = %1
store i8* getelementptr inbounds ([9 x i8], [9 x i8]* @.str.5, i64 0, i64 0), i8** %2
br label %17
11: ; preds = %1
store i8* getelementptr inbounds ([9 x i8], [9 x i8]* @.str.6, i64 0, i64 0), i8** %2
br label %17
12: ; preds = %1
store i8* getelementptr inbounds ([18 x i8], [18 x i8]* @.str.7, i64 0, i64 0), i8** %2
br label %17
13: ; preds = %1
store i8* getelementptr inbounds ([11 x i8], [11 x i8]* @.str.8, i64 0, i64 0), i8** %2
br label %17
14: ; preds = %1
store i8* getelementptr inbounds ([19 x i8], [19 x i8]* @.str.9, i64 0, i64 0), i8** %2
br label %17
15: ; preds = %1
store i8* getelementptr inbounds ([15 x i8], [15 x i8]* @.str.10, i64 0, i64 0), i8** %2
br label %17
16: ; preds = %1
store i8* getelementptr inbounds ([22 x i8], [22 x i8]* @.str.11, i64 0, i64 0), i8** %2
br label %17
17: ; preds = %16, %15, %14, %13, %12, %11, %10, %9, %8, %7, %6, %5
%18 = load i8*, i8** %2
ret i8* %18
}

LLVM IR (-O2):
@.str = [15 x i8] c"Mapped Address\00"
@.str.1 = [17 x i8] c"Response Address\00"
@.str.2 = [15 x i8] c"Change Request\00"
@.str.3 = [15 x i8] c"Source Address\00"
@.str.4 = [16 x i8] c"Changed Address\00"
@.str.5 = [9 x i8] c"Username\00"
@.str.6 = [9 x i8] c"Password\00"
@.str.7 = [18 x i8] c"Message Integrity\00"
@.str.8 = [11 x i8] c"Error Code\00"
@.str.9 = [19 x i8] c"Unknown Attributes\00"
@.str.10 = [15 x i8] c"Reflected From\00"
@.str.11 = [22 x i8] c"Non-RFC3489 Attribute\00"
@reltable.stun_attr2str = [11 x i32] [i32 trunc (i64 sub (i64 ptrtoint ([15 x i8]* @.str to i64), i64 ptrtoint ([11 x i32]* @reltable.stun_attr2str to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([17 x i8]* @.str.1 to i64), i64 ptrtoint ([11 x i32]* @reltable.stun_attr2str to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([15 x i8]* @.str.2 to i64), i64 ptrtoint ([11 x i32]* @reltable.stun_attr2str to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([15 x i8]* @.str.3 to i64), i64 ptrtoint ([11 x i32]* @reltable.stun_attr2str to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([16 x i8]* @.str.4 to i64), i64 ptrtoint ([11 x i32]* @reltable.stun_attr2str to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([9 x i8]* @.str.5 to i64), i64 ptrtoint ([11 x i32]* @reltable.stun_attr2str to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([9 x i8]* @.str.6 to i64), i64 ptrtoint ([11 x i32]* @reltable.stun_attr2str to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([18 x i8]* @.str.7 to i64), i64 ptrtoint ([11 x i32]* @reltable.stun_attr2str to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([11 x i8]* @.str.8 to i64), i64 ptrtoint ([11 x i32]* @reltable.stun_attr2str to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([19 x i8]* @.str.9 to i64), i64 ptrtoint ([11 x i32]* @reltable.stun_attr2str to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([15 x i8]* @.str.10 to i64), i64 ptrtoint ([11 x i32]* @reltable.stun_attr2str to i64)) to i32)]
define i8* @stun_attr2str(i32 %0) {
%2 = add i32 %0, -1
%3 = icmp ult i32 %2, 11
br i1 %3, label %4, label %8
4: ; preds = %1
%5 = sext i32 %2 to i64
%6 = shl i64 %5, 2
%7 = call i8* @llvm.load.relative.i64(i8* bitcast ([11 x i32]* @reltable.stun_attr2str to i8*), i64 %6)
br label %8
8: ; preds = %1, %4
%9 = phi i8* [ %7, %4 ], [ getelementptr inbounds ([22 x i8], [22 x i8]* @.str.11, i64 0, i64 0), %1 ]
ret i8* %9
}