RFR: 8262355: Support for AVX-512 opmask register allocation. [v15]

[Jatin Bhateja]

On Thu, 25 Mar 2021 08:34:36 GMT, Ningsheng Jian <njian at openjdk.org> wrote:

>> Jatin Bhateja has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   8262355: Review comments resolution.
>
> src/hotspot/share/opto/matcher.cpp line 541:
> 
>> 539:    idealreg2spillmask[Op_RegD]->OR(aligned_stack_mask);
>> 540: 
>> 541:   *idealreg2spillmask[Op_RegVMask] = *idealreg2regmask[Op_RegVMask];
> 
> I can still get a SEGV on arm (32bit) build. I think it's here?
> 
> #
> # A fatal error has been detected by the Java Runtime Environment:
> #
> #  SIGSEGV (0xb) at pc=0xfee7ed8e, pid=18153, tid=18162
> #
> # JRE version: OpenJDK Runtime Environment (17.0) (fastdebug build 17-internal+0-git-85a6b6e69)
> # Java VM: OpenJDK Server VM (fastdebug 17-internal+0-git-85a6b6e69, mixed mode, serial gc, linux-arm)
> # Problematic frame:
> # V  [libjvm.so+0xaeed8e]  Matcher::init_first_stack_mask()+0x89d
> #
> # Core dump will be written. Default location: Core dumps may be processed with "/usr/share/apport/apport %p %s %c %d %P" (or dumping to //core.18153)
> #

Accidentally removed earlier Matcher::has_predicated_vectors() checks, thanks for reporting before check-in.

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