const char *token_name(int type) {
  switch (type) {
  case 256:
    return "T_RESTART";
  case 257:
    return "T_ERROR";
  case 258:
    return "T_EOS";
  case 259:
    return "T_WORD";
  case 260:
    return "T_QSTRING";
  case 261:
    return "T_NEWLINE";
  default:
    return "(unknown)";
  }
}


x86 assembly (clang, -O0):
<token_name>:
push   %rbp
mov    %rsp,%rbp
mov    %edi,-0xc(%rbp)
mov    -0xc(%rbp),%eax
add    $0xffffff00,%eax
mov    %eax,%ecx
mov    %rcx,-0x18(%rbp)
sub    $0x5,%eax
ja     1192 <token_name+0x92>
mov    -0x18(%rbp),%rax
lea    0xed7(%rip),%rcx
movslq (%rcx,%rax,4),%rax
add    %rcx,%rax
jmp    *%rax
lea    0xedf(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    119d <token_name+0x9d>
lea    0xed9(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    119d <token_name+0x9d>
lea    0xed1(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    119d <token_name+0x9d>
lea    0xec7(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    119d <token_name+0x9d>
lea    0xebe(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    119d <token_name+0x9d>
lea    0xeb8(%rip),%rax
mov    %rax,-0x8(%rbp)
jmp    119d <token_name+0x9d>
lea    0xeb2(%rip),%rax
mov    %rax,-0x8(%rbp)
mov    -0x8(%rbp),%rax
pop    %rbp
ret

x86 assembly (clang, -O2):
<token_name>:
add    $0xffffff00,%edi
cmp    $0x5,%edi
ja     111d <token_name+0x1d>
movslq %edi,%rax
lea    0xf2b(%rip),%rcx
movslq (%rcx,%rax,4),%rax
add    %rcx,%rax
ret
lea    0xf0f(%rip),%rax
ret

LLVM IR (-O0):
@.str = [10 x i8] c"T_RESTART\00"
@.str.1 = [8 x i8] c"T_ERROR\00"
@.str.2 = [6 x i8] c"T_EOS\00"
@.str.3 = [7 x i8] c"T_WORD\00"
@.str.4 = [10 x i8] c"T_QSTRING\00"
@.str.5 = [10 x i8] c"T_NEWLINE\00"
@.str.6 = [10 x i8] c"(unknown)\00"
define i8* @token_name(i32 %0) {
%2 = alloca i8*
%3 = alloca i32
store i32 %0, i32* %3
%4 = load i32, i32* %3
switch i32 %4, label %11 [
i32 256, label %5
i32 257, label %6
i32 258, label %7
i32 259, label %8
i32 260, label %9
i32 261, label %10
]
5: ; preds = %1
store i8* getelementptr inbounds ([10 x i8], [10 x i8]* @.str, i64 0, i64 0), i8** %2
br label %12
6: ; preds = %1
store i8* getelementptr inbounds ([8 x i8], [8 x i8]* @.str.1, i64 0, i64 0), i8** %2
br label %12
7: ; preds = %1
store i8* getelementptr inbounds ([6 x i8], [6 x i8]* @.str.2, i64 0, i64 0), i8** %2
br label %12
8: ; preds = %1
store i8* getelementptr inbounds ([7 x i8], [7 x i8]* @.str.3, i64 0, i64 0), i8** %2
br label %12
9: ; preds = %1
store i8* getelementptr inbounds ([10 x i8], [10 x i8]* @.str.4, i64 0, i64 0), i8** %2
br label %12
10: ; preds = %1
store i8* getelementptr inbounds ([10 x i8], [10 x i8]* @.str.5, i64 0, i64 0), i8** %2
br label %12
11: ; preds = %1
store i8* getelementptr inbounds ([10 x i8], [10 x i8]* @.str.6, i64 0, i64 0), i8** %2
br label %12
12: ; preds = %11, %10, %9, %8, %7, %6, %5
%13 = load i8*, i8** %2
ret i8* %13
}

LLVM IR (-O2):
@.str = [10 x i8] c"T_RESTART\00"
@.str.1 = [8 x i8] c"T_ERROR\00"
@.str.2 = [6 x i8] c"T_EOS\00"
@.str.3 = [7 x i8] c"T_WORD\00"
@.str.4 = [10 x i8] c"T_QSTRING\00"
@.str.5 = [10 x i8] c"T_NEWLINE\00"
@.str.6 = [10 x i8] c"(unknown)\00"
@reltable.token_name = [6 x i32] [i32 trunc (i64 sub (i64 ptrtoint ([10 x i8]* @.str to i64), i64 ptrtoint ([6 x i32]* @reltable.token_name to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([8 x i8]* @.str.1 to i64), i64 ptrtoint ([6 x i32]* @reltable.token_name to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([6 x i8]* @.str.2 to i64), i64 ptrtoint ([6 x i32]* @reltable.token_name to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([7 x i8]* @.str.3 to i64), i64 ptrtoint ([6 x i32]* @reltable.token_name to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([10 x i8]* @.str.4 to i64), i64 ptrtoint ([6 x i32]* @reltable.token_name to i64)) to i32), i32 trunc (i64 sub (i64 ptrtoint ([10 x i8]* @.str.5 to i64), i64 ptrtoint ([6 x i32]* @reltable.token_name to i64)) to i32)]
define i8* @token_name(i32 %0) {
%2 = add i32 %0, -256
%3 = icmp ult i32 %2, 6
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 ([6 x i32]* @reltable.token_name to i8*), i64 %6)
br label %8
8: ; preds = %1, %4
%9 = phi i8* [ %7, %4 ], [ getelementptr inbounds ([10 x i8], [10 x i8]* @.str.6, i64 0, i64 0), %1 ]
ret i8* %9
}