[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 #16 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Created attachment 46809
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=46809&action=edit
gcc10-pr91635.patch

If you want full patch from me, here it is, but as I said I can't easily test
it (I don't even have cross-glibc or qemu around to test if the testcase FAILs
or PASSes).
I agree the last splitter is changed just for consistency and it is unlikely it
would hit and for the post-reload splitter it will be hard to come up with
testcases.  I've tried to put all 4 testcases from Zdenek into one.