RFR: 8272562: C2: assert(false) failed: Bad graph detected in build_loop_late [v2]

Mon Sep 27 14:09:24 UTC 2021

On Mon, 27 Sep 2021 13:52:53 GMT, Roland Westrelin <roland at openjdk.org> wrote:

>> src/hotspot/share/opto/loopopts.cpp line 1449:
>> 
>>> 1447:       !is_raw_to_oop_cast && // don't extend live ranges of raw oops
>>> 1448:       n->Opcode() != Op_Opaque4 &&
>>> 1449:       (n->Opcode() == Op_CastII && ((CastIINode*)n)->has_range_check())) {
>> 
>> Shouldn't the condition be inverted? This would only allow to sink range check `CastII` nodes.
>> And couldn't you use `!(n->is_CastII() && n->as_CastII()->has_range_check())` instead of the explicit cast?
>
> Right! Thanks for catching this. Actually after thinking more about this, I changed the fix to prevent all nodes that can capture a type from being sunk to be on the safe side, for now.

Sounds good, I guess you will undo that with your general fix later?

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PR: https://git.openjdk.java.net/jdk/pull/5716