[Bug target/49263] SH Target: underutilized "TST #imm, R0" instruction

["oleg dot endo at t-online dot de" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49263

--- Comment #9 from Oleg Endo <oleg.endo@t-online.de> 2011-10-10 23:48:17 UTC ---
Created attachment 25461
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=25461
CSiBE comparisons

(In reply to comment #8)
> 
> Another combine pass to reduce size less than 0.3% on one target
> would be not acceptable, I guess.  

I'm sorry, I forgot to mention that it was just a proof of concept hack
of mine, just to see whether it has any chance to work at all.
I think it would be better to change/fix the behavior of the combine pass
in this regard, so that it tries matching combined patterns without
sophisticated transformations. I will try asking on the gcc list about that.

> ~10 new patterns would be
> overkill for that result, though I'm still expecting that a few
> patterns of them were dominant. 

Yep, even if it turned out to be actually only 8 patterns in total, but
still.. I haven't looked at the issue with SH4A but most likely it would add
another one or two patterns... so basically ~10 :)

> Could you get numbers which pattern
> was used in the former option?

I think it would be a bit too much checking out each individual pattern.
Instead I grouped them into what they are effectively doing.
While I was at it, I also added your peephole idea, and a top 10 listing of
the individual files.