RFR: 8208171: PPC64: Enrich SLP support

Gustavo Romero gromero at linux.vnet.ibm.com
Wed Sep 5 16:20:31 UTC 2018


Hi Martin,

On 09/03/2018 02:18 PM, Doerr, Martin wrote:
> Hi Gustavo and Michihiro,
> 
> we noticed jtreg test failures when using this change:
> compiler/runtime/safepoints/TestRegisterRestoring.java
> compiler/runtime/Test7196199.java
> 
> TestRegisterRestoring is a simple test which returns arbitrary results instead of 10000.

Just to confirm I understood the description correctly:

Where you able to check it's returning random values for the
array instead of 10_000 or you just checked that test failed?

Also, did you pass -XX:-SuperwordUseVSX when it failed? I'm
asking because I'm able to fail that test due to a timeout, but not sure
if it's the same you got there. Look (I'm using the same kernel as yours):

http://cr.openjdk.java.net/~gromero/logs/slp_failure0.txt


Thank you.

Best regards,
Gustavo

> We didn't see it on all machines, so it might be an issue with saving&restoring VR registers in the signal handler.
> The machine which I have used has "SUSE Linux Enterprise Server 12 SP3" with kernel 4.4.126-94.22-default.
> 
> That's what I found out so far. Maybe you have an idea?
> 
> I also noticed that "-XX:-SuperwordUseVSX" crashes with bad ad file when your patch is applied. Looks like matching the vector nodes needs to be prevented.
> 
> Best regards,
> Martin
> 
> 
> -----Original Message-----
> From: hotspot-dev <hotspot-dev-bounces at openjdk.java.net> On Behalf Of Gustavo Romero
> Sent: Montag, 3. September 2018 14:57
> To: Lindenmaier, Goetz <goetz.lindenmaier at sap.com>; Michihiro Horie <HORIE at jp.ibm.com>
> Cc: hotspot compiler <hotspot-compiler-dev at openjdk.java.net>; hotspot-dev at openjdk.java.net
> Subject: Re: RFR: 8208171: PPC64: Enrich SLP support
> 
> Hi Goetz,
> 
> On 09/03/2018 09:27 AM, Lindenmaier, Goetz wrote:
>> Also, I can not find all of the mail traffic in
>> http://mail.openjdk.java.net/pipermail/hotspot-dev/2018-August/thread.html.
>> Is this a problem of the pipermail server?
>>
>> For some reason this webrev lacks the links to browse the diffs.
>> Do you need to use a more recent webrev?  You can obtain it with
>> hg clone http://hg.openjdk.java.net/code-tools/webrev/ .
> 
> Yes, probably it was a problem of the pipermail or in some relay.
> I noted the same thing, i.e. at least one Michi reply arrived
> to me but missed a ML.
> 
> The initial discussion is here:
> http://mail.openjdk.java.net/pipermail/ppc-aix-port-dev/2018-July/003613.html
> 
> I understand Martin reviewed the last webrev in that thread, which is
> http://cr.openjdk.java.net/~mhorie/8208171/webrev.01/  (taken from
> http://mail.openjdk.java.net/pipermail/ppc-aix-port-dev/2018-July/003615.html)
> 
> Martin's review of webrev.01:
> http://mail.openjdk.java.net/pipermail/hotspot-dev/2018-August/033958.html
> 
> and Michi's reply to Martin's review of webrev.01:
> http://mail.openjdk.java.net/pipermail/ppc-aix-port-dev/2018-August/003632.html (with webrev.02,
> taken from http://mail.openjdk.java.net/pipermail/ppc-aix-port-dev/2018-August/003632.html).
> 
> and your last review:
> http://mail.openjdk.java.net/pipermail/hotspot-compiler-dev/2018-September/030419.html
> 
> 
> HTH.
> 
> Best regards,
> Gustavo
>    
>> Why do you rename vnoreg to vnoregi?
>>
>> Besides that the change is fine, thanks for implementing this!
>>
>> Best regards,
>>     Goetz.
>>
>>
>>> -----Original Message-----
>>> From: Doerr, Martin
>>> Sent: Dienstag, 28. August 2018 19:35
>>> To: Gustavo Romero <gromero at linux.vnet.ibm.com>; Michihiro Horie
>>> <HORIE at jp.ibm.com>
>>> Cc: Lindenmaier, Goetz <goetz.lindenmaier at sap.com>; hotspot-
>>> dev at openjdk.java.net; ppc-aix-port-dev at openjdk.java.net; Simonis, Volker
>>> <volker.simonis at sap.com>
>>> Subject: RE: RFR: 8208171: PPC64: Enrich SLP support
>>>
>>> Hi Michihiro,
>>>
>>> thank you for implementing it. I have just taken a first look at your
>>> webrev.01.
>>>
>>> It looks basically good. Only the Power version check seems to be incorrect.
>>> VM_Version::has_popcntb() checks for Power5.
>>> I believe most instructions are available with Power7.
>>> Some ones (vsubudm, ..., vmmuluwm, vpopcntw) were introduced with
>>> Power8?
>>> We should check this carefully.
>>>
>>> Also, indentation in register_ppc.hpp could get improved.
>>>
>>> Thanks and best regard,
>>> Martin
>>>
>>>
>>> -----Original Message-----
>>> From: Gustavo Romero <gromero at linux.vnet.ibm.com>
>>> Sent: Donnerstag, 26. Juli 2018 16:02
>>> To: Michihiro Horie <HORIE at jp.ibm.com>
>>> Cc: Lindenmaier, Goetz <goetz.lindenmaier at sap.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>
>>> Subject: Re: RFR: 8208171: PPC64: Enrich SLP support
>>>
>>> Hi Michi,
>>>
>>> On 07/26/2018 01:43 AM, Michihiro Horie wrote:
>>>> I updated webrev:
>>>> http://cr.openjdk.java.net/~mhorie/8208171/webrev.01/
>>>
>>> Thanks for providing an updated webrev and for fixing indentation and
>>> function
>>> order in assembler_ppc.inline.hpp as well. I have no further comments :)
>>>
>>>
>>> Best Regards,
>>> Gustavo
>>>
>>>>
>>>> Best regards,
>>>> --
>>>> Michihiro,
>>>> IBM Research - Tokyo
>>>>
>>>> Inactive hide details for Gustavo Romero ---2018/07/25 23:05:32---Hi Michi,
>>> On 07/25/2018 02:43 AM, Michihiro Horie wrote:Gustavo Romero ---
>>> 2018/07/25 23:05:32---Hi Michi, On 07/25/2018 02:43 AM, Michihiro Horie
>>> wrote:
>>>>
>>>> From: Gustavo Romero <gromero at linux.vnet.ibm.com>
>>>> To: Michihiro Horie/Japan/IBM at IBMJP, ppc-aix-port-
>>> dev at openjdk.java.net, hotspot-dev at openjdk.java.net
>>>> Cc: goetz.lindenmaier at sap.com, volker.simonis at sap.com, "Doerr, Martin"
>>> <martin.doerr at sap.com>
>>>> Date: 2018/07/25 23:05
>>>> Subject: Re: RFR: 8208171: PPC64: Enrich SLP support
>>>>
>>>> -------------------------------------------------------------------------------------------
>>> ----------------------------------------------------------------------------------------------
>>> ----------------------------------------------------------------------------------------------
>>> ----------------------------------------------------------------------------------------------
>>> ----------------------------------------------------------------------------------------------
>>> ----------------------------------------------------------------------------------------------
>>> ----------------------------------------------------------------------------------------------
>>> ----------------------------------------------------------------------------------------------
>>> ----------------------------------------------------------------------------------------------
>>> ----------------------------------------------------------------------------------------------
>>> -----------------------------------------------------
>>>>
>>>>
>>>>
>>>> Hi Michi,
>>>>
>>>> On 07/25/2018 02:43 AM, Michihiro Horie wrote:
>>>>    > Dear all,
>>>>    >
>>>>    > Would you review the following change?
>>>>    > Bug: https://bugs.openjdk.java.net/browse/JDK-8208171
>>>>    > Webrev: http://cr.openjdk.java.net/~mhorie/8208171/webrev.00
>>>>    >
>>>>    > This change adds support for vectorized arithmetic calculation with SLP.
>>>>    >
>>>>    > The to_vr function is added to convert VSR to VR. Currently, vecX is
>>> associated with a VSR class vs_reg that only defines VSR32-51 in ppc.ad,
>>> which are exactly overlapped with VRs. Instruction APIs receiving VRs use the
>>> to_vr via vecX. Another thing is the change in sqrtF_reg to enable the
>>> matching with SqrtVF. I think the change in sqrtF_reg would be fine due to
>>> the ConvD2FNode::Value in convertnode.cpp.
>>>>
>>>> Looks good. Just a few comments:
>>>>
>>>> - In vmul4F_reg() would it be reasonable to use xvmulsp instead of
>>> vmaddfp in
>>>>      order to avoid the splat?
>>>>
>>>> - Although all instructions added by your change where introduced in ISA
>>> 2.06,
>>>>      so POWER7 and above are OK, as I see probes for
>>> PowerArchictecturePPC64=6|5 in
>>>>      vm_version_ppc.cpp (line 64),  I'm wondering if there is any control point
>>> to
>>>>      guarantee that these instructions won't be emitted on a CPU that does
>>> not
>>>>      support them.
>>>>
>>>> - I think that in general string in format %{} are in upper case. For instance,
>>>>      this the current output on optoassembly for vmul4F:
>>>>
>>>> 2941835 5b4     ADDI    R24, R24, #64
>>>> 2941836 5b8     vmaddfp  VSR32,VSR32,VSR36      ! mul packed4F
>>>> 2941837 5c0     STXVD2X     [R17], VSR32        // store 16-byte Vector
>>>>
>>>>      I think it would be better to be in upper case instead. I also think that if
>>>>      the node match emits more than one instruction all instructions must be
>>> listed
>>>>      in format %{}, since it's meant for detailed debugging. Finally I think it
>>>>      would be better to replace \t! by \t// in that string (unless I'm missing any
>>>>      special meaning for that char). So for vmul4F it would be something like:
>>>>
>>>> 2941835 5b4     ADDI      R24, R24, #64
>>>>                    VSPLTISW  VSR34, 0                 // Splat 0 imm in VSR34
>>>> 2941836 5b8     VMADDFP   VSR32,VSR32,VSR36,VSR34  // Mul packed4F
>>>> 2941837 5c0     STXVD2X   [R17], VSR32             // store 16-byte Vector
>>>>
>>>>
>>>> But feel free to change anything just after you get additional reviews :)
>>>>
>>>>
>>>>    > I confirmed this change with JTREG. In addition, I used attached micro
>>> benchmarks.
>>>>    > /(See attached file: slp_microbench.zip)/
>>>>
>>>> Thanks for sharing it.
>>>> Btw, another option to host it would be in the CR
>>>> server, in http://cr.openjdk.java.net/~mhorie/8208171
>>>>
>>>>
>>>> Best regards,
>>>> Gustavo
>>>>
>>>>    >
>>>>    > Best regards,
>>>>    > --
>>>>    > Michihiro,
>>>>    > IBM Research - Tokyo
>>>>    >
>>>>
>>>>
>>>>
>>
> 



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