8213754: PPC64: Add Intrinsics for isDigit/isLowerCase/isUpperCase/isWhitespace

[Michihiro Horie]

Hi Martin,

Thank you for giving your helpful comments. I did not recognize “
generate_method_call_static” prevents any optimizations, but I now checked
it actually degraded the performance, thanks.

>Please note that we don’t have a machine, yet. So other people will have
to test.
I think Gustavo can help testing this change when its' ready.

>Would it be possible to introduce more fine-grained intrinsics such that
the “slow” path is outside of them?
>
>Maybe you can factor out as in the following example?
>if (latin1) return isLatin1Digit(codePoint);
>with isLatin1Digit as HotSpotIntrinsicCandidate.
Thanks for an example, please let me try to separate the Latin block from
other blocks for some time.


Best regards,
--
Michihiro,
IBM Research - Tokyo



From:	"Doerr, Martin" <martin.doerr at sap.com>
To:	Michihiro Horie <HORIE at jp.ibm.com>,
            "hotspot-compiler-dev at openjdk.java.net"
            <hotspot-compiler-dev at openjdk.java.net>,
            "ppc-aix-port-dev at openjdk.java.net"
            <ppc-aix-port-dev at openjdk.java.net>
Cc:	"Simonis, Volker" <volker.simonis at sap.com>, "Lindenmaier,
            Goetz" <goetz.lindenmaier at sap.com>, Gustavo Romero
            <gromero at linux.vnet.ibm.com>
Date:	2018/11/20 01:55
Subject:	RE: 8213754: PPC64: Add Intrinsics for
            isDigit/isLowerCase/isUpperCase/isWhitespace



Hi Michihiro,

first of all, thanks for working on Power9 optimizations. Please note that
we don’t have a machine, yet. So other people will have to test.

I think it may be problematic to insert a slow path by
“generate_method_call_static”. This may be a performance disadvantage for
some users of other encodings because your intrinsics prevent inlining and
further optimizations.
Would it be possible to introduce more fine-grained intrinsics such that
the “slow” path is outside of them?

Maybe you can factor out as in the following example?
if (latin1) return isLatin1Digit(codePoint);
with isLatin1Digit as HotSpotIntrinsicCandidate.

I can’t judge if this is needed, but I think this should be discussed first
before going into the details.

Best regards,
Martin


From: Michihiro Horie <HORIE at jp.ibm.com>
Sent: Freitag, 16. November 2018 12:53
To: hotspot-compiler-dev at openjdk.java.net;
ppc-aix-port-dev at openjdk.java.net
Cc: Doerr, Martin <martin.doerr at sap.com>; Simonis, Volker
<volker.simonis at sap.com>; Lindenmaier, Goetz <goetz.lindenmaier at sap.com>;
Gustavo Romero <gromero at linux.vnet.ibm.com>
Subject: RFR: 8213754: PPC64: Add Intrinsics for
isDigit/isLowerCase/isUpperCase/isWhitespace



Dear all,

Would you please review following change?

Bug: https://bugs.openjdk.java.net/browse/JDK-8213754
Webrev: http://cr.openjdk.java.net/~mhorie/8213754/webrev.00

This change includes the intrinsics of Character isDigit, isLowerCase,
isUpperCase, and isWhitespace to support the Latin1 block using POWER9’s
instructions cmprb and cmpeqb. The cmprb enables to compare a character
with 1 or 2 ranged bytes, while the cmpeqb compares one with 1 to 8 values.
Simple micro benchmark attached showed improvements by 20-40%.

(See attached file: Latin1Test.java)


Best regards,
--
Michihiro,
IBM Research - Tokyo





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