[Bug target/91635] wrong code at -O2 with __builtin_add_overflow() and shifts

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91635

--- Comment #15 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Then gen_rtx_REG (mode, REGNO (SUBREG_REG (x))) case I meant only in case some
splitter would be required for proper operation rather than just being an
optimization.  If they are all an optimization, the !paradoxical_subreg_p
guards are probably ok.