PPC64 VSX load/store instructions in stubs

[Gustavo Romero]

Hi Michihiro

Thanks a lot for providing a result summary for byte, short, int, and
long.

Using VSR0, 1, 2, and 3 (instead of the VR registers) will not violate
the ABI, so you can use them as Martin suggested.

Martin, should we use the same BugID (8154156: https://goo.gl/z2eGLi)
for byte, short, int, and long webrevs or open a new one?

Thank you.

Best regards,
Gustavo

On 30-05-2016 06:56, Doerr, Martin wrote:
> Hi Michihiro,
> 
> thanks for implementing the VSX versions.
> 
> Gustavo's change "8154156: PPC64: improve array copy stubs by using vector instructions" is pushed into hs-comp.
> Your change needs to get adapted:
> 
> -          The vm_version and assembler parts are already there.
> 
> -          Vector-scalar load/store instructions use VectorSRegisters, now.
> 
> The byte and int version look good to me. I think the long version should be implemented in a similar way: check for has_vsx() is necessary, the length comparison should be done inside of the block.
> 
> Best regards,
> Martin
> 
> 
> From: Michihiro Horie [mailto:HORIE at jp.ibm.com]
> Sent: Montag, 30. Mai 2016 03:43
> To: Miki M Enoki <ENOMIKI at jp.ibm.com>
> Cc: Breno Leitao <brenohl at br.ibm.com>; Gustavo Romero <gromero at linux.vnet.ibm.com>; hotspot-dev at openjdk.java.net; Doerr, Martin <martin.doerr at sap.com>; ppc-aix-port-dev at openjdk.java.net; Simonis, Volker <volker.simonis at sap.com>; Volker Simonis <volker.simonis at gmail.com>
> Subject: Re: PPC64 VSX load/store instructions in stubs
> 
> 
> Dear Breno, Gustavo, Voker, and Martin,
> I am a cowoker of Miki.
> 
> I implemented VSX disjoint arraycopy functions for byte, int, and long. Although Miki had implemented VSX disjoint long arraycopy, we found a couple of bugs so I fixed it. Would you please review them?
> 
> Micro benchmarks for byte and int are as follows. (The one for long is the same as Miki's, which was attached before by Miki)
> (See attached file: ArrayCopyTest_byte.java)(See attached file: ArrayCopyTest_int.java)
> 
> Results are as follows. (For the short result, I used Gustavo's code.)
> (See attached file: result_disjoint-arraycopy_vsx-max.jpg)
> 
> Patch for Java8:
> (See attached file: hotspot_jdk8.diff)
> 
> Patch for Java9:
> (See attached file: hotspot_jdk9.diff)
> 
> Best regards,
> --
> Michihiro Horie,
> IBM Research - Tokyo
> 
> [Inactive hide details for Miki M Enoki---2016/05/25 00:15:19---Hi Breno, Thank you for your reply.]Miki M Enoki---2016/05/25 00:15:19---Hi Breno, Thank you for your reply.
> 
> From: Miki M Enoki/Japan/IBM
> To: Breno Leitao <brenohl at br.ibm.com<mailto:brenohl at br.ibm.com>>
> Cc: Gustavo Romero <gromero at linux.vnet.ibm.com<mailto:gromero at linux.vnet.ibm.com>>, "hotspot-dev at openjdk.java.net<mailto:hotspot-dev at openjdk.java.net>" <hotspot-dev at openjdk.java.net<mailto:hotspot-dev at openjdk.java.net>>, "Doerr, Martin" <martin.doerr at sap.com<mailto:martin.doerr at sap.com>>, "ppc-aix-port-dev at openjdk.java.net<mailto:ppc-aix-port-dev at openjdk.java.net>" <ppc-aix-port-dev at openjdk.java.net<mailto:ppc-aix-port-dev at openjdk.java.net>>, "Simonis, Volker" <volker.simonis at sap.com<mailto:volker.simonis at sap.com>>, Volker Simonis <volker.simonis at gmail.com<mailto:volker.simonis at gmail.com>>
> Date: 2016/05/25 00:15
> Subject: Re: PPC64 VSX load/store instructions in stubs
> 
> ________________________________
> 
> 
> Hi Breno,
> 
> Thank you for your reply.
> 
>> The same mechanism could be used to copy arrays of short elements, as Gustavo was
>> working on. Do you agree?
> 
> I think the mechanism is different with type (byte, short, int, long...).
> Gustavo will apply a pach with VSX for short array copy, so it would be reasonable to use VSX instruction for long array copy, too.
> 
> My coworker is also creating byte and int arraycopy with VSX. He will post an email to this mailing list.
> I appreciate it if our patch for byte, int and long copy is applied to OpenJDK.
> 
> 
> Best regards,
> Miki
> 
> 
> 
> 
> [Inactive hide details for Breno Leitao ---2016/05/17 02:29:32---Hi Miki, On 05/16/2016 02:53 AM, Miki M Enoki wrote:]Breno Leitao ---2016/05/17 02:29:32---Hi Miki, On 05/16/2016 02:53 AM, Miki M Enoki wrote:
> 
> From: Breno Leitao <brenohl at br.ibm.com<mailto:brenohl at br.ibm.com>>
> To: Miki M Enoki/Japan/IBM at IBMJP, "Doerr, Martin" <martin.doerr at sap.com<mailto:martin.doerr at sap.com>>,
> Cc: Gustavo Romero <gromero at linux.vnet.ibm.com<mailto:gromero at linux.vnet.ibm.com>>, Volker Simonis <volker.simonis at gmail.com<mailto:volker.simonis at gmail.com>>, "Simonis, Volker" <volker.simonis at sap.com<mailto:volker.simonis at sap.com>>, "ppc-aix-port-dev at openjdk.java.net<mailto:ppc-aix-port-dev at openjdk.java.net>" <ppc-aix-port-dev at openjdk.java.net<mailto:ppc-aix-port-dev at openjdk.java.net>>, "hotspot-dev at openjdk.java.net<mailto:hotspot-dev at openjdk.java.net>" <hotspot-dev at openjdk.java.net<mailto:hotspot-dev at openjdk.java.net>>
> Date: 2016/05/17 02:29
> Subject: Re: PPC64 VSX load/store instructions in stubs
> ________________________________
> 
> 
> 
> Hi Miki,
> 
> On 05/16/2016 02:53 AM, Miki M Enoki wrote:
>> I also implemented VSX disjoint long arraycopy.
>> I appreciate it if it is applied to OpenJDK, too.
> 
> Thanks for the summarized information, this is helpful. Based on your plot, I
> understand we can split the whole scenario in two:
> 
>  * Array size smaller than 4k, and then use VSX instructions to perform copy
>  * Array size bigger than 4k, and then use VMX instructions to perform copy
> 
> The same mechanism could be used to copy arrays of short elements, as Gustavo was
> working on. Do you agree?
> 
> That said, I understand that a new patch should be generated that contemplates
> both cases on a single patch, ready to be applied on OpenJDK 9 source code. Hence
> a webrev should be generated mapping to bug id
> https://bugs.openjdk.java.net/browse/JDK-8154156
> 
> If you need any help on the webrev[1] creation and hosting, Gustavo might help,
> since he did this process already.
> 
> [1] http://openjdk.java.net/guide/webrevHelp.html
> 
>