[Bug target/64305] [SH] Add support for fschg insn and 64 bit FP moves

[olegendo at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64305

--- Comment #3 from Oleg Endo <olegendo at gcc dot gnu.org> ---
One potential trap when using mode-switching for FPSCR.SZ could be LRA, which
currently doesn't seem to be looking at the insn mode.  This was a problem in
PR 55212, where LRA would insert fldi0 and fldi1 insns in double-precision mode
code.

I can imagine something similar would happen even more so when dealing with
other fmov insns.  Perhaps LRA needs to be taught to take insn mode-switching
into account.