RFR: 8265784: [C2] Hoisting of DecodeN leaves MachTemp inputs behind [v2]

[Goetz Lindenmaier]

On Mon, 3 May 2021 14:04:22 GMT, Martin Doerr <mdoerr at openjdk.org> wrote:

>> PPC64 and s390 have DecodeN implementations which use a MachTemp input. When LCM hoists the DecodeN, the MachTemp nodes reside in the old block, but should get hoisted together with the DecodeN node.
>> Same is true for load Base input which exists on s390 for example. Unfortunately, that's just a platform specific MachNode which is not nicely recognizable in LCM.
>
> Martin Doerr has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Add temp node placement assertion.

LGTM

-------------

Marked as reviewed by goetz (Reviewer).

PR: https://git.openjdk.java.net/jdk/pull/3637