From: Eric Wong <normalperson@...>
Date: 2014-03-18T19:42:38+00:00
Subject: [ruby-core:61579] Re: [ruby-trunk - Feature #9425] [PATCH] st: use power-of-two sizes to avoid slow modulo ops

funny.falcon@gmail.com wrote:
>  Can you test this
>   + if (SYMBOL_P(a)) a = (a >> RUBY_SPECIAL_SHIFT) ^ (a >>
>  (RUBY_SPECIAL_SHIFT + 3)); /* 3=ID_SCOPE_SHIFT */

Seems to hurt performance on x86 compared to my original.  I don't think
ID scope bits are useful for this case.  From what I've seen, Ruby users
tend to limit symbol names to \w when using the Hash class and keywords.