[Bug target/65153] [SH][4.9 Regression] "insn does not satisfy its constraints" when compiling libmcrypt

["olegendo at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65153

--- Comment #9 from Oleg Endo <olegendo at gcc dot gnu.org> ---
(In reply to Oleg Endo from comment #8)
> 
> I've tried to disable the peephole on trunk and compared CSiBE results.  It
> seems the peephole doesn't hit very often:
> sum:  3371887 -> 3371943    +56 / +0.001661 %
> 
> So we could probably remove the complex peephole without a big loss.
> 
> I have a set of similar but simpler peepholes with a higher hit rate.  Maybe
> we can replace the complex peephole with some simpler ones.

The set of peepholes can be found in PR 61142, attachment 34839.
CSiBE numbers with that patch:

sum:  3371887 -> 3367967    -3920 / -0.116255 %
avg: -217.777778 / -0.167780 %
max: replaypc-0.4.0.preproc   57212 -> 57188          -24 / -0.041949 %
min: mpeg2dec-0.3.1           54348 -> 53984         -364 / -0.669758 %

and with the patch, but without the problematic peephole of this PR:

sum:  3371887 -> 3367983    -3904 / -0.115781 %
avg: -216.888889 / -0.167686 %
max: replaypc-0.4.0.preproc   57212 -> 57188          -24 / -0.041949 %
min: mpeg2dec-0.3.1           54348 -> 53984         -364 / -0.669758 %

It seems that the other set of peepholes covers most of the cases of the
complex peephole.