[Bug target/94042] [10 Regression] Bootstrap fails on ppc-linux-gnu

[vmakarov at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94042

--- Comment #31 from Vladimir Makarov <vmakarov at gcc dot gnu.org> ---
(In reply to Segher Boessenkool from comment #30)
> r10-6919 isn't good for Power, btw.  Why would it *ever* be a good idea?

This heuristic avoid creating small gaps in hard reg file which prevent
assignments for multi-reg pseudos.

It decreases average SPEC2000 code size and improves performance at least for
Intel i7-9700K (0.5% for SPECINT2000 and about 1% for SPECFP2000).  It also
solves some recent arm testsuite failures (expected use of callee-clobbered
hard regs for multi-regs pseudos).

I understand the frustration.  Sorry for creating it.  Unfortunately in RA
heuristic patches there is no a perfect solution.  Somebody will always be
upset.