RFR(M): 8152172: PPC64: Support AES intrinsics

Vladimir Kozlov vladimir.kozlov at oracle.com
Fri Mar 25 23:00:04 UTC 2016


This question is for core libs.

For JIT to generate optimal code we want to change type of AESCrypt::sessionK from Object[] to int[][].
Otherwise JIT have to generate checkcast code to make sure that elements of sessionK array are int[].
I see that sessionK field is private so we are not changing public API.

Thanks,
Vladimir

On 3/24/16 6:17 PM, Hiroshi H Horii wrote:
> Hi Vladimir,
>
> Thank you for your reviewing.
>
> Is it possible to modify the type of sessionK from Object[] to int[][]?
>
> We can guess, the type was designed for flexibility. However, only int[] is used
> to store elements of sessionK, so far. In addition, this field is private.
> Though adding checkcast is another solution, it produces overheads.
>
> I attached an additional patch (generated with hg diff -g) to jdk directory.
> I would like to ask thoughts about this change of java code.
>
>
>
> Regards,
> Hiroshi
> -----------------------
> Hiroshi Horii,
> IBM Research - Tokyo
>
>
> Vladimir Kozlov <vladimir.kozlov at oracle.com> wrote on 03/24/2016 09:09:11:
>
>  > From: Vladimir Kozlov <vladimir.kozlov at oracle.com>
>  > To: Hiroshi H Horii/Japan/IBM at IBMJP, "hotspot-compiler-
>  > dev at openjdk.java.net" <hotspot-compiler-dev at openjdk.java.net>
>  > Cc: "Doerr, Martin" <martin.doerr at sap.com>, Tim Ellison
>  > <Tim_Ellison at uk.ibm.com>, "Simonis, Volker" <volker.simonis at sap.com>
>  > Date: 03/24/2016 09:19
>  > Subject: Re: RFR(M): 8152172: PPC64: Support AES intrinsics
>  >
>  > I think we need to add gen_checkcast for objAESCryptKey node since
>  > java code has no guarantee that sessionK array elements are
>  > initialized with int[]. Or we should modify java code to declare sessionK
>  > as int[][].
>  >
>  > Thanks,
>  > Vladimir
>  >
>  > Note, intrinsics are correctly handle case when
>  > On 3/22/16 8:47 AM, Hiroshi H Horii wrote:
>  > > Dear all:
>  > >
>  > > Can I please request reviews for the following change?
>  > > This change was created for JDK 9 to enable POWER8's AES
>  > > instructions for AES calculation.
>  > >
>  > > This request follows this discussion.
>  > > http://mail.openjdk.java.net/pipermail/hotspot-compiler-dev/2016-
>  > March/021926.html
>  > >
>  > > Description:
>  > > This change adds stub routines support for single-block AES
>  > > encryption and decryption operations on the POWER8 platform.
>  > > They are available only when the application is configured to
>  > > use SunJCE crypto provider on little endian.
>  > >
>  > > These stubs make use of efficient hardware AES instructions
>  > > and thus offer significant performance improvements over
>  > > JITed code on POWER8 as on x86 and SPARC. AES stub routines
>  > > are enabled by default on POWER8 platforms that support AES
>  > > instructions (vcipher). They can be explicitly enabled or
>  > > disabled on the command-line using UseAES and
>  > > UseAESIntrinsics JVM flags. Unlike x86 and SPARC, vcipher
>  > > and vnchiper of POWER8 need the same round keys of AES.
>  > > Therefore, inline_aescrypt_Block in library_call.cpp calls the
>  > > stub with AESCrypt.sessionK[0] as round keys.
>  > >
>  > > Summary of source code changes:
>  > >
>  > >   *src/cpu/ppc/vm/assembler_ppc.hpp
>  > >   *src/cpu/ppc/vm/assembler_ppc.inline.hpp
>  > >     - Adds support for vrld instruction to rotate vector register values
>  > >        with left doubleword.
>  > >
>  > >   *src/cpu/ppc/vm/stubGenerator_ppc.cpp
>  > >     - Defines stubs for single-block AES encryption and decryption
>  > >        routines supporting all key sizes (128, 192 and 256-bit).
>  > >     - Current POWER AES decryption instructions are not compatible
>  > >        with SunJCE expanded decryption key format. Thus decryption
>  > >        stubs read the expanded encryption keys (sessionK[0]) with
>  > >        descendant order.
>  > >     - Encryption stubs use SunJCE expanded encryption key as their
>  > >        is no incompatibility issue between POWER8 AES encryption
>  > >        instructions and SunJCE expanded encryption keys.
>  > >
>  > >   *src/cpu/ppc/vm/vm_version_ppc.cpp
>  > >     - Detects AES capabilities of the underlying CPU by using
>  > >        has_vcipher().
>  > >     - Enables UseAES and UseAESIntrinsics flags if the underlying
>  > >        CPU supports AES instructions and neither of them is explicitly
>  > >        disabled on the command-line. Generate warning message if
>  > >        either of these flags are enabled on the command-line
>  > >        whereas the underlying CPU does not support AES instructions.
>  > >
>  > >   *src/share/vm/opto/library_call.cpp
>  > >      - Passes the first input parameter, reference to sessionK[0] to the
>  > >         AES stubs only on the POWER platform.
>  > >
>  > >    *src/share/vm/opto/graphKit.cpp
>  > >      - Supports T_NARROWOOP type for GraphKit::load_array_element.
>  > >
>  > > Bug: https://bugs.openjdk.java.net/browse/JDK-8152172
>  > > Webrev: http://cr.openjdk.java.net/~mdoerr/8152172_ppc64le_aes/webrev.00/
>  > >
>  > >
>  > > Regards,
>  > > Hiroshi
>  > > -----------------------
>  > > Hiroshi Horii,
>  > > IBM Research - Tokyo
>  > >
>  >
>



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