On 1/26/22 04:11, Martin Liška wrote:
Hello.
Right now, switch lowering does not update basic_block::count values
so that they are uninitiliazed. Moreover, I've updated probability scaling
when a more complex expansion happens. There are still some situations
where
the profile is a bit imprecise, but the patch improves rapidly the
current situation.
Patch can bootstrap on x86_64-linux-gnu and survives regression tests.
Ready to be installed?
Thanks,
Martin
PR tree-optimization/101301
PR tree-optimization/103680
gcc/ChangeLog:
* tree-switch-conversion.cc (bit_test_cluster::emit):
Handle correctly remaining probability.
(switch_decision_tree::try_switch_expansion): Fix BB's count
where a cluster expansion happens.
(switch_decision_tree::emit_cmp_and_jump_insns): Fill up also
BB count.
(switch_decision_tree::do_jump_if_equal): Likewise.
(switch_decision_tree::emit_case_nodes): Handle special case
for BT expansion which can also fallback to a default BB.
* tree-switch-conversion.h (cluster::cluster): Add
m_default_prob probability.
Funny you just ping'd this patch. I've held it in my queue for months
as I didn't see it get installed.
As far as I'm concerned, you know the switch conversion bits better than
anyone. If you think the patch significantly improves the profile
handling for switch conversion, then I'd say go for it. Particularly
since it seems to fix at least two known bugs.
Keff
