[tor-bugs] #8897 [Tor]: Faster curve25519 implementation for ntor

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#8897: Faster curve25519 implementation for ntor
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     Reporter:  nickm    |      Owner:  nickm
         Type:           |     Status:  needs_revision
  enhancement            |  Milestone:  Tor: 0.2.7.x-final
     Priority:  major    |    Version:
    Component:  Tor      |   Keywords:  tor-relay, performance, ntor,
   Resolution:           |  026-triaged-0, 027-triaged-1-in
Actual Points:           |  Parent ID:  #9662
       Points:           |
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Comment (by yawning):

 Has anyone (apart from me) benchmarked this stuff recently in isolation
 from #9663?

 On a i5-4250U (TurboBoost etc), I get:
  * Andrew M. SSE2 (`-O3 -m64 -DCURVE25519_SSE2`): 203194 ticks (clang:
 160530 ticks)
  * Andrew M. (`-O3 -m64`): 125878 ticks (clang: 136594 ticks)
  * agl c64 (`-O3 -m64`): 134442 ticks (clang: 150482 ticks)

 This is compiling with gcc 5.1.0, clang 3.6.1.  On x86_64 this doesn't
 feel worth it at all, especially considering that anyone who cares about
 Curve25519 performance is going to probably be hosting a high traffic HS,
 and should be on something modern with a 64 bit processor.

 How much do we care about 32 bit performance for this sort of thing
 anyway?

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Ticket URL: <https://trac.torproject.org/projects/tor/ticket/8897#comment:21>
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