Nested CPR patch review

[Simon Peyton Jones]

Yes, I apologise for being tardy.  It's on my stack.  Just swamped.

Simon

|  -----Original Message-----
|  From: Matthew Pickering [mailto:matthewtpickering at gmail.com]
|  Sent: 29 January 2018 09:35
|  To: Sebastian Graf <sgraf1337 at gmail.com>
|  Cc: Simon Peyton Jones <simonpj at microsoft.com>; GHC developers <ghc-
|  devs at haskell.org>; Joachim Breitner <mail at joachim-breitner.de>;
|  tkn.akio at gmail.com
|  Subject: Re: Nested CPR patch review
|  
|  Would one of you have time to review this patch now?
|  
|  Is there something more needed?
|  
|  Matt
|  
|  On Sun, Jan 7, 2018 at 10:11 AM, Sebastian Graf <sgraf1337 at gmail.com>
|  wrote:
|  > I've since run NoFib. You can find the results here:
|  > https://phabricator.haskell.org/D4244#119697
|  >
|  > I wonder if you feel that any more notes are needed? The general
|  idea
|  > of CPR remained the same, it's just the extension of the DmdResult
|  > lattice that needs some rationale as to why and when these new
|  values are needed.
|  >
|  > I also wonder what the impact of "Slightly strengthen the strictness
|  > analysis"
|  >
|  (https://ghc.haskell.org/trac/ghc/wiki/NestedCPR/Akio2017#Changestothe
|  > demandanalyzer)
|  > would be if regarded in isolation.
|  >
|  > On Tue, Jan 2, 2018 at 11:52 AM, Matthew Pickering
|  > <matthewtpickering at gmail.com> wrote:
|  >>
|  >> I don't think anyone has run nofib on the rebased branch yet.
|  >>
|  >> The Akio2017 subpage is a more accurate summary. Sebastian has also
|  >> been adding notes to explain the more intricate parts.
|  >>
|  >> Matt
|  >>
|  >> On Fri, Dec 22, 2017 at 5:27 PM, Simon Peyton Jones
|  >> <simonpj at microsoft.com> wrote:
|  >> > Terrific!
|  >> >
|  >> > What are the nofib results?
|  >> >
|  >> > Can we have a couple of artificial benchmarks in
|  cpranal/should_run
|  >> > that show substantial perf improvements because the nested CPR
|  wins
|  >> > in some inner loop?
|  >> >
|  >> > Is https://ghc.haskell.org/trac/ghc/wiki/NestedCPR still an
|  accurate
|  >> > summary of the idea?   And the Akio2017 sub-page?  It would be
|  easier to
|  >> > review the code if the design documentation accurately described
|  it.
|  >> >
|  >> > I'll look in the new year.  Thanks!
|  >> >
|  >> > Simon
|  >> >
|  >> > |  -----Original Message-----
|  >> > |  From: Matthew Pickering [mailto:matthewtpickering at gmail.com]
|  >> > |  Sent: 22 December 2017 17:09
|  >> > |  To: GHC developers <ghc-devs at haskell.org>; Simon Peyton Jones
|  >> > | <simonpj at microsoft.com>; Joachim Breitner
|  >> > | <mail at joachim-breitner.de>;  tkn.akio at gmail.com; Sebastian Graf
|  >> > | <sgraf1337 at gmail.com>
|  >> > |  Subject: Nested CPR patch review
|  >> > |
|  >> > |  Hi all,
|  >> > |
|  >> > |  I recently resurrected akio's nested cpr branch and put it on
|  >> > phabricator
|  >> > |  for review.
|  >> > |
|  >> > |  https://phabricator.haskell.org/D4244
|  >> > |
|  >> > |  Sebastian has kindly been going over it and ironed out a few
|  >> > | kinks in
|  >> > the
|  >> > |  last few days. He says now that he believes the patch is
|  correct.
|  >> > |
|  >> > |  Is there anything else which needs to be done before merging
|  >> > | this
|  >> > patch?
|  >> > |
|  >> > |  Simon, would you perhaps be able to give the patch a look
|  over?
|  >> > |
|  >> > |  Cheers,
|  >> > |
|  >> > |  Matt
|  >
|  >