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

[kito at gcc dot gnu.org]

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

--- Comment #7 from Kito Cheng <kito at gcc dot gnu.org> ---
Hi Jakub:

> that doesn't mean paradoxical subregs can't appear there, just it will be 
> less likely.

Does it mean paradoxical subregs will appear during intermediate result even
after reload, so for such split pattern with smaller mode than word_mode we
should check it's paradoxical subreg or not?

Thanks