[Bug target/117182] [SH] LRA changes fp-move insn alternative without validating fp-mode-switching state

[olegendo at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=117182

--- Comment #11 from Oleg Endo <olegendo at gcc dot gnu.org> ---
(In reply to Vladimir Makarov from comment #10)
> I added a patch.  Could somebody check that it solves the problem.

I've tried the patch with the case from comment #2 and it doesn't it.

Looking at the patch, I don't see anything that would address the actual
underlying problem: insn modifications are done without validating that
mode-switching requirements of the insn are still met after the change.

Maybe the added SUBREG check in curr_insn_transform helps some other corner
case.  But this case here has nothing to do with it.