8179527: Implement intrinsic code for reverseBytes with load/store
Michihiro Horie
HORIE at jp.ibm.com
Fri Jun 2 12:15:32 UTC 2017
Volker,
I used OProfile's opannotate to verify the nodes are matched.
Best regards,
--
Michihiro,
IBM Research - Tokyo
From: Volker Simonis <volker.simonis at gmail.com>
To: Michihiro Horie <HORIE at jp.ibm.com>
Cc: Gustavo Bueno Romero <gromero at br.ibm.com>, Hiroshi H Horii
<HORII at jp.ibm.com>, "hotspot-dev at openjdk.java.net"
<hotspot-dev at openjdk.java.net>, "Doerr, Martin"
<martin.doerr at sap.com>, "ppc-aix-port-dev at openjdk.java.net"
<ppc-aix-port-dev at openjdk.java.net>
Date: 2017/06/02 20:11
Subject: Re: 8179527: Implement intrinsic code for reverseBytes with
load/store
Hi Michihiro,
thanks a lot for providing your micro-benchmarks.
So, did you use PrintAssemby/PrintOtpoAssembly to verify that the new nodes
are matched?
Regards,
Volker
On Fri, Jun 2, 2017 at 11:28 AM, Michihiro Horie <HORIE at jp.ibm.com> wrote:
Volker,
Thank you very much for the 2nd review.
Attached includes micro benchmarks I used for the verification.
(See attached file: reverseBytesBench.tar.gz)
Best regards,
--
Michihiro,
IBM Research - Tokyo
Inactive hide details for Volker Simonis ---2017/06/02 17:04:16---Hi
Michihiro, Martin, thanks a lot for the change Michihiro aVolker Simonis
---2017/06/02 17:04:16---Hi Michihiro, Martin, thanks a lot for the
change Michihiro and thanks for the thorough review
From: Volker Simonis <volker.simonis at gmail.com>
To: "Doerr, Martin" <martin.doerr at sap.com>
Cc: Michihiro Horie <HORIE at jp.ibm.com>, Gustavo Bueno Romero <
gromero at br.ibm.com>, Hiroshi H Horii <HORII at jp.ibm.com>, "
hotspot-dev at openjdk.java.net" <hotspot-dev at openjdk.java.net>
Date: 2017/06/02 17:04
Subject: Re: 8179527: Implement intrinsic code for reverseBytes with
load/store
Hi Michihiro, Martin,
thanks a lot for the change Michihiro and thanks for the thorough review
Martin :)
I'm just wondering if you had some test-cases to verify if the new nodes
really match?
Change looks good now.
Regards,
Volker
On Thu, Jun 1, 2017 at 6:00 PM, Doerr, Martin <martin.doerr at sap.com>
wrote:
Hi Michihiro,
thank you very much for providing the new webrev (with support for
older Power processors, which was missing in webrev.02):
http://cr.openjdk.java.net/~horii/8179527/webrev.03/
I have built and executed the VM on a Power6 machine. Thanks for
supporting it.
I would have spent only one flag for has_ldbrx/has_stdbrx, but I’m
ok with it. The change looks good to me and I will sponsor it after
2nd review.
Best regards,
Martin
From: Doerr, Martin
Sent: Mittwoch, 31. Mai 2017 15:54
To: 'Michihiro Horie' <HORIE at jp.ibm.com>; Volker Simonis (
volker.simonis at gmail.com) <volker.simonis at gmail.com>
Cc: Gustavo Bueno Romero <gromero at br.ibm.com>; Hiroshi H Horii <
HORII at jp.ibm.com>; hotspot-dev at openjdk.java.net
Subject: RE: 8179527: Implement intrinsic code for reverseBytes
with load/store
Hi Michihiro,
thank you for the new webrev with all of my suggestions. Looks good
to me.
There’s only a trailing whitespace which I had to remove to satisfy
“hg jcheck” (otherwise push attempt would get rejected).
We’ll run tests. Maybe we can get a 2nd review in the meantime?
Best regards,
Martin
From: Michihiro Horie [mailto:HORIE at jp.ibm.com]
Sent: Mittwoch, 31. Mai 2017 14:36
To: Doerr, Martin <martin.doerr at sap.com>
Cc: Gustavo Bueno Romero <gromero at br.ibm.com>; Hiroshi H Horii <
HORII at jp.ibm.com>; hotspot-dev at openjdk.java.net; Simonis, Volker <
volker.simonis at sap.com>; ppc-aix-port-dev at openjdk.java.net
Subject: RE: 8179527: Implement intrinsic code for reverseBytes
with load/store
Martin,
Thank you very much for your helpful comments and sponsoring this
change.
Would you review the latest change?
http://cr.openjdk.java.net/~horii/8179527/webrev.02/
Best regards,
--
Michihiro,
IBM Research - Tokyo
Inactive hide details for "Doerr, Martin" ---2017/05/30
01:26:01---Hi Michihiro, thanks for the improved webrev. This looks
bet"Doerr, Martin" ---2017/05/30 01:26:01---Hi Michihiro, thanks
for the improved webrev. This looks better, but I still have a
couple of sugges
From: "Doerr, Martin" <martin.doerr at sap.com>
To: Michihiro Horie <HORIE at jp.ibm.com>
Cc: "hotspot-dev at openjdk.java.net" <hotspot-dev at openjdk.java.net>,
"Simonis, Volker" <volker.simonis at sap.com>, Hiroshi H Horii <
HORII at jp.ibm.com>, Gustavo Bueno Romero <gromero at br.ibm.com>
Date: 2017/05/30 01:26
Subject: RE: 8179527: Implement intrinsic code for reverseBytes
with load/store
Hi Michihiro,
thanks for the improved webrev. This looks better, but I still have
a couple of suggestions.
1.
I still don’t like match rules which contain nodes which do
something else (even though direct matching is prohibited by
predicate).
I think it would be better to remove “match(…)”, “predicate(false)”
and “ins_const(…)” and just describe the “effect()”. At least, I’m
not aware of why a match rule should be needed for rldicl and
extsh.
2.
I’d appreciate if you could remove “predicate
(UseCountLeadingZerosInstructionsPPC64)” from all byte_reverse_...
rules. They don’t make any sense (not your fault).
3.
The costs seem not to be set appropriately in the byte_reverse_...
rules. E.g. instruction count * DEFAULT_COST would be better.
4.
The load/store byte reversed instructions should use the 2 operand
form (no explicit 0 for R0 to support assertions).
Maybe we can find a 2nd reviewer if you provide a new webrev. I can
sponsor the change.
Thanks and best regards,
Martin
From: Michihiro Horie [mailto:HORIE at jp.ibm.com]
Sent: Montag, 8. Mai 2017 06:58
To: Doerr, Martin <martin.doerr at sap.com>; Lindenmaier, Goetz <
goetz.lindenmaier at sap.com>
Cc: Gustavo Serra Scalet <gustavo.scalet at eldorado.org.br>;
hotspot-dev at openjdk.java.net; ppc-aix-port-dev at openjdk.java.net;
Simonis, Volker <volker.simonis at sap.com>; Hiroshi H Horii <
HORII at jp.ibm.com>; Gustavo Bueno Romero <gromero at br.ibm.com>
Subject: RE: 8179527: Implement intrinsic code for reverseBytes
with load/store
Dear Martin, Gustavo,
Thank you very much for your helpful comments.
Fixed code is
http://cr.openjdk.java.net/~horii/8179527/webrev.01/
Dear Goetz,
Would you kindly review and sponsor this change?
I heard you are a C2 compiler expert and Martin is out for a while.
Best regards,
--
Michihiro,
IBM Research - Tokyo
Inactive hide details for "Doerr, Martin" ---2017/05/03
02:24:18---Hi Michihiro and Gustavo, thank you very much for
implementi"Doerr, Martin" ---2017/05/03 02:24:18---Hi Michihiro and
Gustavo, thank you very much for implementing this change.
From: "Doerr, Martin" <martin.doerr at sap.com>
To: Gustavo Serra Scalet <gustavo.scalet at eldorado.org.br>,
Michihiro Horie/Japan/IBM at IBMJP
Cc: "ppc-aix-port-dev at openjdk.java.net" <
ppc-aix-port-dev at openjdk.java.net>, "hotspot-dev at openjdk.java.net"
<hotspot-dev at openjdk.java.net>, "Simonis, Volker" <
volker.simonis at sap.com>
Date: 2017/05/03 02:24
Subject: RE: 8179527: Implement intrinsic code for reverseBytes
with load/store
Hi Michihiro and Gustavo,
thank you very much for implementing this change.
@Gustavo: Thanks for taking a look.
I think that the direct match rules are just there to satisfy
match_rule_supported. They don't need to be fast, they are just a
fall back solution.
The goal is to exploit the byte reverse load and store instructions
which should match in more performance critical cases.
Now my review:
assembler_ppc.hpp:
Looks good except a minor formatting request:
LDBRX_OPCODE = (31u << OPCODE_SHIFT | 532 << 1),
should be
LDBRX_OPCODE = (31u << OPCODE_SHIFT | 532u << 1),
to be consistent.
The comments // X-FORM should be aligned with the other ones.
assembler_ppc.inline.hpp:
Good.
ppc.ad:
I'm concerned about the additional match rules which are only used
for the expand step. They could match directly leading to incorrect
code. What they match is not what they do.
I suggest to implement the code directly in the ins_encode. This
would make the new code significantly shorter and less error prone.
I think we don't need to optimize for Power6 anymore and newer
processors shouldn't really suffer under a little less optimized
instruction scheduling. Would you agree?
Displacements may be too large for "li" so I suggest to use the
"indirect" memory operand and let the compiler handle it. I know
that it may increase latency because the compiler will need to
insert an addition which could better be matched into the memory
operand of the load which is harder to implement (it is possible to
match an addition in an operand).
Best regards,
Martin
-----Original Message-----
From: Gustavo Serra Scalet [mailto:gustavo.scalet at eldorado.org.br]
Sent: Dienstag, 2. Mai 2017 17:05
To: Michihiro Horie <HORIE at jp.ibm.com>
Cc: ppc-aix-port-dev at openjdk.java.net; hotspot-dev at openjdk.java.net
; Simonis, Volker <volker.simonis at sap.com>; Doerr, Martin <
martin.doerr at sap.com>
Subject: RE: 8179527: Implement intrinsic code for reverseBytes
with load/store
Hi Michihiro,
I wonder if there is no vectorized approach for implementing your
"bytes_reverse_long_Ex" instruct on ppc.ad. Or did you avoid doing
it so intentionally?
> -----Original Message-----
> From: ppc-aix-port-dev [mailto:ppc-aix-port-dev-
> bounces at openjdk.java.net] On Behalf Of Michihiro Horie
> Sent: terça-feira, 2 de maio de 2017 11:47
> To: ppc-aix-port-dev at openjdk.java.net;
hotspot-dev at openjdk.java.net;
> volker.simonis at sap.com; martin.doerr at sap.com
> Subject: 8179527: Implement intrinsic code for reverseBytes with
> load/store
>
> Dear all,
>
> Would you please review following change?
>
> Bug: https://bugs.openjdk.java.net/browse/JDK-8179527
> Webrev: http://cr.openjdk.java.net/~horii/8179527/webrev.00/
>
> I added new intrinsic code for reverseBytes() in ppc.ad with
> * match(Set dst (ReverseBytesI/L/US/S (LoadI src)));
> * match(Set dst (StoreI dst (ReverseBytesI/L/US/S src)));
>
>
> Best regards,
> --
> Michihiro,
> IBM Research - Tokyo
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