RFR(S): 8210660: PPC64: Mapping floating point registers to vsx registers in ppc.ad

Michihiro Horie HORIE at jp.ibm.com
Thu Sep 13 17:05:08 UTC 2018


Hi Martin,

Thank you so much for your review (and adding the ID in the subject :-).

>I don’t think we need 2 nodes for ReplicateF with vector length 4. Both
ones in your webrev are for Power8 so only one will be used.
You're right, thanks. I removed a redundant one.

I also refactored ReplicateD with vector length 2.

Following is the latest webrev:
http://cr.openjdk.java.net/~mhorie/8210660/webrev.01/


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>
Cc:	Gustavo Romero <gromero at linux.vnet.ibm.com>, "Lindenmaier,
            Goetz" <goetz.lindenmaier at sap.com>
Date:	2018/09/13 16:25
Subject:	RE: RFR(S): 8210660: PPC64: Mapping floating point registers to
            vsx registers in ppc.ad



Hi Michihiro,

I have added “RFR(S): 8210660” to the subject.

I don’t think we need 2 nodes for ReplicateF with vector length 4. Both
ones in your webrev are for Power8 so only one will be used.
Besides this, your change looks good to me.

Would you like to improve ReplicateD with vector length 2, too?

Thanks and best regards,
Martin


From: Michihiro Horie <HORIE at jp.ibm.com>
Sent: Mittwoch, 12. September 2018 18:11
To: hotspot-compiler-dev at openjdk.java.net
Cc: Doerr, Martin <martin.doerr at sap.com>; Gustavo Romero
<gromero at linux.vnet.ibm.com>; Lindenmaier, Goetz
<goetz.lindenmaier at sap.com>
Subject: RFR: PPC64: Mapping floating point registers to vsx registers in
ppc.ad



Dear all,

Would you please review the following change?

Bug: https://bugs.openjdk.java.net/browse/JDK-8210660
Webrev: http://cr.openjdk.java.net/~mhorie/8210660/webrev.00/

In the current code emit for replicating the floating point value in
ppc.ad, a floating point value is once stored in order to load as an
integer value. However, when SuperwordUseVSX is enabled, this is redundant
because the floating point registers are overlapped with vsx registers
0-31. We can use vsx instructions for replicating the floating point value
by mapping the floating point register to the vsx register.


Best regards,
--
Michihiro,
IBM Research - Tokyo





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