RFR(L): 8198894: [PPC64] More generic vector CRC implementation

[Michihiro Horie]

Hi Martin,

>Michihiro, can I add you as 2nd reviewer (no need to be jdk-reviewer for
that)?
Sure. I had a look at the code, and I'm ok with the change.

Best regards,
--
Michihiro,
IBM Research - Tokyo



From:	"Doerr, Martin" <martin.doerr at sap.com>
To:	Michihiro Horie <HORIE at jp.ibm.com>
Cc:	"Lindenmaier, Goetz" <goetz.lindenmaier at sap.com>, Gustavo
            Romero <gromero at linux.vnet.ibm.com>, "Hiroshi H Horii
            (HORII at jp.ibm.com)" <HORII at jp.ibm.com>,
            "'hotspot-compiler-dev at openjdk.java.net'"
            <hotspot-compiler-dev at openjdk.java.net>
Date:	2018/03/10 02:17
Subject:	RE: RFR(L): 8198894: [PPC64] More generic vector CRC
            implementation



Hi Michihiro and Götz,

thanks, Götz, for reviewing.

Michihiro, can I add you as 2nd reviewer (no need to be jdk-reviewer for
that)? I think you have taken a look and you obviously ran tests. So if
you’re ok with the change, I can push it next week.

Our nightly tests look good, too.

Thanks and best regards,
Martin


From: Michihiro Horie [mailto:HORIE at jp.ibm.com]
Sent: Freitag, 2. März 2018 11:55
To: Doerr, Martin <martin.doerr at sap.com>
Cc: Lindenmaier, Goetz <goetz.lindenmaier at sap.com>; Gustavo Romero
<gromero at linux.vnet.ibm.com>; Hiroshi H Horii (HORII at jp.ibm.com)
<HORII at jp.ibm.com>; 'hotspot-compiler-dev at openjdk.java.net'
<hotspot-compiler-dev at openjdk.java.net>
Subject: Re: RFR(L): 8198894: [PPC64] More generic vector CRC
implementation



Hi Martin,

I double checked performance with our micro benchmark.
This change was 5 times faster. In addition, I did not observe degradation
with smaller length but have almost equal performance.

Best regards,
--
Michihiro,
IBM Research - Tokyo

Inactive hide details for "Doerr, Martin" ---2018/03/02 00:49:56---Hi, I
have implemented a more generic version of the vector "Doerr, Martin"
---2018/03/02 00:49:56---Hi, I have implemented a more generic version of
the vector instruction based CRC code.

From: "Doerr, Martin" <martin.doerr at sap.com>
To: "'hotspot-compiler-dev at openjdk.java.net'" <
hotspot-compiler-dev at openjdk.java.net>
Cc: "Lindenmaier, Goetz" <goetz.lindenmaier at sap.com>, "Hiroshi H Horii (
HORII at jp.ibm.com)" <HORII at jp.ibm.com>, "Michihiro Horie (HORIE at jp.ibm.com)"
<HORIE at jp.ibm.com>, Gustavo Romero <gromero at linux.vnet.ibm.com>
Date: 2018/03/02 00:49
Subject: RFR(L): 8198894: [PPC64] More generic vector CRC implementation




Hi,

I have implemented a more generic version of the vector instruction based
CRC code.
It supports CRC32C and Big Endian, too.

The peak performance was even better for large input streams. I got almost
40GB/s.
Some smaller length may be slower than with the old version.
Maybe somebody from IBM would like to double-check performance.

Please review:
http://cr.openjdk.java.net/~mdoerr/8198894_PPC64_CRC32/webrev.00/
(hoping you like math J)

Best regards,
Martin

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