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Re: [patch] Remove strange case cost code
On Tue, Apr 17, 2012 at 10:45 AM, Richard Guenther
<richard.guenther@gmail.com> wrote:
>> Also it is possble to get an historgrams from profile feedback into
>> switch expansion. I always wanted to do that once switch expansion code
>> is cleaned up and moved to gimple level...
>
> Indeed. ?At least the parts that expand switch stmts to (balanced) trees
> should be moved to the GIMPLE level, retaining only the table-jump-like
> expansions as switch stmts.
My goal for GCC 4.8 is to do just that: Move switch expansion to
GIMPLE and add value profiling for switch expressions. I may put back
that heuristic as a branch predictor, but I doubt it makes much of a
difference. Besides, it is actually hard to figure out whether a
switch expression is for characters in an ascii string because char is
promoted to int.
Ciao!
Steven