Early inline

[Simon Peyton Jones]

I can see that

- it'd be nice to associate the perf improvements with the right patch
- it'd be nice to associate the error-message wibbles with the right patch
- it'd be nice to Phab them all so others can comment

But life is short, so I'd be perfectly happy if we were able to just commit them, provided they validate collectively.    It's up to you guys.

There may be some more error message wibbles when you do full run (didn't have time to do that before leaving).

Don't squash them.. each patch does something separate... it's not a stream of successive fixes to the same thing.  I've already done the squashing.

The SetLevels changes strictly subsume everything in the separate patch I sent Ben (cc ghc-devs) fixing #13255, and will conflict with it.  If so, ignore the latter.

Simon


 -----Original Message-----
| From: David Feuer [mailto:david at well-typed.com]
| Sent: 17 February 2017 18:33
| To: ghc-devs at haskell.org; Simon Peyton Jones <simonpj at microsoft.com>
| Cc: Ben Gamari <ben at well-typed.com>; Reid Barton <rwbarton at gmail.com>;
| David Feuer <david.feuer at gmail.com>
| Subject: Re: Early inline
| 
| Yes, we definely want these. Are you wanting each of these submitted as a
| separate differential *in order*? Or do you want a more complex mix-and-
| match?
| Also, are there any commits you think should be squashed?
| 
| On Friday, February 17, 2017 4:41:33 PM EST Simon Peyton Jones via ghc-
| devs
| wrote:
| > Ben, David, Reid
| > I have been working for months (on and off, mostly off, but very ON
| > for the last week or two) on a very simple idea: the simplifier should
| > inline things even in the "gentle" phase. It seems so simple.  And it
| > is: the key patch is tiny.
| > But it stressed corners of the optimiser that were not stressed
| > before; and digging into it showed opportunities I did not know about
| > before. So I have ended up a with a whole series of patches, which are
| > on wip/spj-early-inline branch
| >
| > 7f14d15c0e5fc2c9a81db3d0f0b01d85857b1d87 Error message wibbles
| > accumulated from the preceding patches
| >
| > 0499c65d9fa45e7879e1e1264fdaa15274adcba6 Improve SetLevels for join
| > points
| >
| > 3b2fc0827ff6cafa34836c2d9dc710b628c990b6 Change -ddump-tc-trace output
| > in TcErrors, slightly
| >
| > 9ffdf62b0ca72c4f35579f9d6f31a9beebf23025 Improve pretty-printing of
| > types
| >
| > 3f346eac06399a79adf48425018ee949cee245bf Add VarSet.anyDVarSet,
| > allDVarSet
| >
| > 912e71eb3b4ec91e805ecf2236d1033e55e2933a The Early Inline Patch
| >
| > 7188cd13f8e54efa764d52ca016b87b3669b29f5 Small changes to expression
| > sizing in CoreUnfold
| >
| > bfc6fa3f377d11bdfcdbf82b65bf2f39cb00b90c Fix SetLevels for
| > makeStaticPtr
| >
| > 8b1cfea089faacb5b95ffcc3511e05faeabb8076 Extend CSE to handle
| > recursive bindings
| >
| > 50411995641802568bb27c867afe804f91e0524c Combine identical case
| > alterantives in CSE
| >
| > 2e077ccc736a0b2a622b7f42b7929966bddb4ded Inline data constructor
| > wrappers in phase 2 only
| >
| > b868de53dd19f639c1070089ecff21948ff33e0d Make Specialise work with
| > casts
| >
| > c767ae5f04a09ef71dcb8f67a17225a52c2cc5d2 Stop uniques ending up in
| > SPEC rule names
| >
| > b49ed1f0102f93ca7f62632c436b41bd240b501f Occurrence-analyse the result
| > of rule firings
| >
| > 607a735dfb99bb8f0edf466ccb01e732218c42ec Add -fspec-constr-keen
| >
| > 67a0c1872c0515f1f12ea68097a84e02da92f45b Refactor floating of bindings
| > (fiBind)
| >
| > e90f4d7c6d3003039fa1647a3da3dafcaa75527b More tracing in SpecConstr
| >
| >
| > Much to my surprise, we get some jolly nice improvements in compiler
| perf:
| >
| > 3%   perf/compiler/T5837.run            T5837 [stat too good] (normal)
| >
| > 7%   perf/compiler/parsing001.run       parsing001 [stat too good]
| (normal)
| >
| > 9%   perf/compiler/T12234.run           T12234 [stat too good] (optasm)
| >
| > 35%  perf/compiler/T9020.run            T9020 [stat too good] (optasm)
| >
| > 9%   perf/compiler/T3064.run            T3064 [stat too good] (normal)
| >
| > 13%  perf/compiler/T9961.run            T9961 [stat too good] (normal)
| >
| > 20%  perf/compiler/T13056.run           T13056 [stat too good] (optasm)
| >
| > 5%   perf/compiler/T9872d.run           T9872d [stat too good] (normal)
| >
| > 5%   perf/compiler/T9872c.run           T9872c [stat too good] (normal)
| >
| > 5%   perf/compiler/T9872b.run           T9872b [stat too good] (normal)
| >
| > 7%   perf/compiler/T9872a.run           T9872a [stat too good] (normal)
| >
| > 5%   perf/compiler/T783.run             T783 [stat too good] (normal)
| >
| > 35%   perf/compiler/T12227.run           T12227 [stat too good]
| (normal)
| >
| > 20%   perf/compiler/T1969.run            T1969 [stat too good] (normal)
| >
| > 5%   perf/should_run/lazy-bs-alloc.run  lazy-bs-alloc [stat too good]
| > (normal)
| >
| > 5%   perf/compiler/T12707.run         T12707 [stat too good] (normal)
| >
| >
| >
| > 4%   perf/compiler/T3294.run            T3294 [stat too good] (normal)
| >
| > 1.5% perf/space_leaks/T4029.run         T4029 [stat too good] (ghci)
| >
| > So what is left?  I have sunk so much time into this and am still not
| QUITE
| > out of the woods.   I was left with
| >
| > Unexpected failures:
| >
| >    codeGen/should_compile/debug.run              debug [bad stdout]
| (normal)
| >
| >    concurrent/should_run/T4030.run               T4030 [bad exit code]
| > (normal) I'm re-validating having pulled from HEAD, but I THINK that's
| all.
| > Now
| >
| > *         I don't know how to Phab these individually
| >
| > *         I have not sweated through which patch is responsible for
| which
| > perf improvments.  Maybe Gipeda can tell?
| >
| > *         I have not put each error message change with the correct
| patch.
| > I don't know how much that matters. So this is to say: anything you
| guys
| > can do to help get this actually Done would be really helpful.   I'm
| out of
| > time till Monday at least. It would be great to collect those
| > performance improvements!
| > Thanks!
| > Simon
|