[Bug target/81924] [6 Regression] ICE: in simplify_binary_operation_1, at simplify-rtx.c:3678 on powerpc64le-linux-gnu

["wschmidt at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81924

--- Comment #6 from Bill Schmidt <wschmidt at gcc dot gnu.org> ---
The patch applies cleanly to gcc-6-branch, and I can certainly commit that
(although I can't show a case where it can happen with present behavior, it
should be cleaned up).

For gcc-5-branch, the patch doesn't apply cleanly, and there would be a lot of
work to establish prerequisites for it to do so.  I was hoping to be able to
offer Matthias a small patch despite GCC 5 being closed, but that doesn't look
feasible.  The problem is that the patch relies on TImode being hostable in VSX
registers, which was not introduced until GCC 6; prior to that it only resides
in a pair of GPRs.

But that means that the problem in GCC 5 is probably different from the V1TI
splitting that Jakub referenced; that code just isn't there.  I'll see if I can
understand this better.