Use POWER8 and POWER9 ISA enhancements to improve the performance of GHASH. Demonstrate why achieved performance of AES-GCM is close to optimal for the platform (i.e matching or beating OpenSSL performance).
Optimized assembly implementations in the Cryptogams repository[1] may serve as useful reference. C-based intrinsic implementations are discouraged. Financial bounty upon completion, community acceptance of patches, and bounty reviewer input.
| Status | Assigned | Task | ||
|---|---|---|---|---|
| Open | jukivili | T4460 libgcrypt performance TODOs | ||
| Resolved | jukivili | T4531 PowerPC performance improvements | ||
| Resolved | slandden | T4630 libgcrypt: POWER GHASH Vector Acceleration |
Please STOP adding such bug reports or feature requests. They are not helpful and such discussion are better done at the mailing list. In case you want to spend money to speed up things you may contact gnupg.com for a quote.
C-based intrinsic implementations are discouraged.
What do you mean? This means that the compiler can do the register allocation, and I just learned clang can even do unrolling of loops for you. The openssl version for single-block (no unrolling) aes was half the speed of a c-based intrinsic implementation because there were things in the loop that didn't need to be there.
Please note that C-based intrinsic implementation is the way to go now as that is the path chosen for PowerPC implementations in libgcrypt.
Allow me to clarify. For bounty purposes, as long as the intrinsic implementation matches or beats OpenSSL performance, it is acceptable. There have been cases where the use of certain intrinsics may yield better performing, but sub optimal results.
@jukivili, thanks for the heads up.
@slandden, would you please point me to the single-block AES code you mentioned? Are you also referring to https://dev.gnupg.org/rC92f38a619b1cf759057e9cd532ae7c1d0331100f ?
El vie., 8 nov. 2019 8:19, johnmar (John Martinez) <noreply@dev.gnupg.org>
escribió:
johnmar added a comment.
Allow me to clarify. For bounty purposes, as long as the intrinsic
implementation matches or beats OpenSSL performance, it is acceptable.
There have been cases where the use of certain intrinsics may yield better
performing, but sub optimal results.@jukivili https://dev.gnupg.org/p/jukivili/, thanks for the heads up.
@slandden https://dev.gnupg.org/p/slandden/, would you please point me
to the single-block AES code you mentioned? Are you also referring to
https://dev.gnupg.org/rC92f38a619b1cf759057e9cd532ae7c1d0331100f ?
Yes, and the opendsl code is here
https://github.com/openssl/openssl/blob/master/crypto/aes/asm/aesp8-ppc.pl#L464
While the register allocator is good (and reduces the number of things to
keep in ones head while ñrogramming dramatically), as well as the loop
optimizer. I don't think the compiler can generate constants loadable only
from the instruction stream. Openssl shows one way to do this, and it would
also be possible to unconditionally jump over data placed in the
instruction stream.
*TASK DETAIL*
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I am about half way. Sorry for the slowness.
El lun., 9 dic. 2019 20:50, jukivili (Jussi Kivilinna) <
noreply@dev.gnupg.org> escribió:
jukivili added a comment.
I've been wondering this also. I can start working on this.
*TASK DETAIL*
https://dev.gnupg.org/T4630*EMAIL PREFERENCES*
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*Cc: *raksprak, jukivili, slandden, werner, gcwilson, johnmar, pmgdeb,srgblnchtrn, gp_ast, lumag
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