RFR: 8262355: Support for AVX-512 opmask register allocation. [v8]

[Vladimir Ivanov]

On Tue, 16 Mar 2021 12:32:53 GMT, Vladimir Ivanov <vlivanov at openjdk.org> wrote:

>> Jatin Bhateja has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   8262355: Removing object re-materialization handling for mask-generating nodes during de-opt, it will be added separately.
>
> src/hotspot/share/opto/matcher.cpp line 664:
> 
>> 662:   *idealreg2debugmask  [Op_RegD] = *idealreg2spillmask[Op_RegD];
>> 663:   *idealreg2debugmask  [Op_RegP] = *idealreg2spillmask[Op_RegP];
>> 664:   if (Matcher::has_predicated_vectors()) {
> 
> Any specific motivation to have `RegVMask` case guarded? FTR `Vec[XYZ...]` cases aren't irrespective of support.

Still curious.

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PR: https://git.openjdk.java.net/jdk/pull/2768