[Git][ghc/ghc][wip/simplifier-fixes] 19 commits: Fix arityType: -fpedantic-bottoms, join points, etc
Matthew Pickering (@mpickering)
gitlab at gitlab.haskell.org
Fri Aug 26 10:14:22 UTC 2022
Matthew Pickering pushed to branch wip/simplifier-fixes at Glasgow Haskell Compiler / GHC
Commits:
a90298cc by Simon Peyton Jones at 2022-08-25T08:38:16+01:00
Fix arityType: -fpedantic-bottoms, join points, etc
This MR fixes #21694, #21755. It also makes sure that #21948 and
fix to #21694.
* For #21694 the underlying problem was that we were calling arityType
on an expression that had free join points. This is a Bad Bad Idea.
See Note [No free join points in arityType].
* To make "no free join points in arityType" work out I had to avoid
trying to use eta-expansion for runRW#. This entailed a few changes
in the Simplifier's treatment of runRW#. See
GHC.Core.Opt.Simplify.Iteration Note [No eta-expansion in runRW#]
* I also made andArityType work correctly with -fpedantic-bottoms;
see Note [Combining case branches: andWithTail].
* Rewrote Note [Combining case branches: optimistic one-shot-ness]
* arityType previously treated join points differently to other
let-bindings. This patch makes them unform; arityType analyses
the RHS of all bindings to get its ArityType, and extends am_sigs.
I realised that, now we have am_sigs giving the ArityType for
let-bound Ids, we don't need the (pre-dating) special code in
arityType for join points. But instead we need to extend the env for
Rec bindings, which weren't doing before. More uniform now. See
Note [arityType for let-bindings].
This meant we could get rid of ae_joins, and in fact get rid of
EtaExpandArity altogether. Simpler.
* And finally, it was the strange treatment of join-point Ids in
arityType (involving a fake ABot type) that led to a serious bug:
#21755. Fixed by this refactoring, which treats them uniformly;
but without breaking #18328.
In fact, the arity for recursive join bindings is pretty tricky;
see the long Note [Arity for recursive join bindings]
in GHC.Core.Opt.Simplify.Utils. That led to more refactoring,
including deciding that an Id could have an Arity that is bigger
than its JoinArity; see Note [Invariants on join points], item
2(b) in GHC.Core
* Make sure that the "demand threshold" for join points in DmdAnal
is no bigger than the join-arity. In GHC.Core.Opt.DmdAnal see
Note [Demand signatures are computed for a threshold arity based on idArity]
* I moved GHC.Core.Utils.exprIsDeadEnd into GHC.Core.Opt.Arity,
where it more properly belongs.
* Remove an old, redundant hack in FloatOut. The old Note was
Note [Bottoming floats: eta expansion] in GHC.Core.Opt.SetLevels.
Compile time improves very slightly on average:
Metrics: compile_time/bytes allocated
---------------------------------------------------------------------------------------
T18223(normal) ghc/alloc 725,808,720 747,839,216 +3.0% BAD
T6048(optasm) ghc/alloc 105,006,104 101,599,472 -3.2% GOOD
geo. mean -0.2%
minimum -3.2%
maximum +3.0%
For some reason Windows was better
T10421(normal) ghc/alloc 125,888,360 124,129,168 -1.4% GOOD
T18140(normal) ghc/alloc 85,974,520 83,884,224 -2.4% GOOD
T18698b(normal) ghc/alloc 236,764,568 234,077,288 -1.1% GOOD
T18923(normal) ghc/alloc 75,660,528 73,994,512 -2.2% GOOD
T6048(optasm) ghc/alloc 112,232,512 108,182,520 -3.6% GOOD
geo. mean -0.6%
I had a quick look at T18223 but it is knee deep in coercions and
the size of everything looks similar before and after. I decided
to accept that 3% increase in exchange for goodness elsewhere.
Metric Decrease:
T10421
T18140
T18698b
T18923
T6048
Metric Increase:
T18223
- - - - -
909edcfc by Ben Gamari at 2022-08-25T10:03:34-04:00
upload_ghc_libs: Add means of passing Hackage credentials
- - - - -
28402eed by M Farkas-Dyck at 2022-08-25T10:04:17-04:00
Scrub some partiality in `CommonBlockElim`.
- - - - -
54affbfa by Ben Gamari at 2022-08-25T20:05:31-04:00
hadrian: Fix whitespace
Previously this region of Settings.Packages was incorrectly indented.
- - - - -
c4bba0f0 by Ben Gamari at 2022-08-25T20:05:31-04:00
validate: Drop --legacy flag
In preparation for removal of the legacy `make`-based build system.
- - - - -
822b0302 by Ben Gamari at 2022-08-25T20:05:31-04:00
gitlab-ci: Drop make build validation jobs
In preparation for removal of the `make`-based build system
- - - - -
6fd9b0a1 by Ben Gamari at 2022-08-25T20:05:31-04:00
Drop make build system
Here we at long last remove the `make`-based build system, it having
been replaced with the Shake-based Hadrian build system. Users are
encouraged to refer to the documentation in `hadrian/doc` and this [1]
blog post for details on using Hadrian.
Closes #17527.
[1] https://www.haskell.org/ghc/blog/20220805-make-to-hadrian.html
- - - - -
dbb004b0 by Ben Gamari at 2022-08-25T20:05:31-04:00
Remove testsuite/tests/perf/haddock/.gitignore
As noted in #16802, this is no longer needed.
Closes #16802.
- - - - -
fe9d824d by Ben Gamari at 2022-08-25T20:05:31-04:00
Drop hc-build script
This has not worked for many, many years and relied on the now-removed
`make`-based build system.
- - - - -
659502bc by Ben Gamari at 2022-08-25T20:05:31-04:00
Drop mkdirhier
This is only used by nofib's dead `dist` target
- - - - -
4a426924 by Ben Gamari at 2022-08-25T20:05:31-04:00
Drop mk/{build,install,config}.mk.in
- - - - -
46924b75 by Ben Gamari at 2022-08-25T20:05:31-04:00
compiler: Drop comment references to make
- - - - -
d387f687 by Harry Garrood at 2022-08-25T20:06:10-04:00
Add inits1 and tails1 to Data.List.NonEmpty
See https://github.com/haskell/core-libraries-committee/issues/67
- - - - -
8603c921 by Harry Garrood at 2022-08-25T20:06:10-04:00
Add since annotations and changelog entries
- - - - -
6b47aa1c by Krzysztof Gogolewski at 2022-08-25T20:06:46-04:00
Fix redundant import
This fixes a build error on x86_64-linux-alpine3_12-validate.
See the function 'loadExternalPlugins' defined in this file.
- - - - -
478c374e by Matthew Pickering at 2022-08-26T11:13:19+01:00
Revert "Revert "Refactor SpecConstr to use treat bindings uniformly""
This reverts commit 851d8dd89a7955864b66a3da8b25f1dd88a503f8.
This commit was originally reverted due to an increase in space usage.
This was diagnosed as because the SCE increased in size and that was
being retained by another leak. See #22102
- - - - -
fc51f26f by Matthew Pickering at 2022-08-26T11:13:19+01:00
Avoid retaining bindings via ModGuts held on the stack
It's better to overwrite the bindings fields of the ModGuts before
starting an iteration as then all the old bindings can be collected as
soon as the simplifier has processed them. Otherwise we end up with the
old bindings being alive until right at the end of the simplifier pass
as the mg_binds field is only modified right at the end.
- - - - -
466eadff by Matthew Pickering at 2022-08-26T11:13:19+01:00
Force imposs_deflt_cons in filterAlts
This fixes a pretty serious space leak as the forced thunk would retain
`Alt b` values which would then contain reference to a lot of old
bindings and other simplifier gunk.
The OtherCon unfolding was not forced on subsequent simplifier runs so
more and more old stuff would be retained until the end of
simplification.
Fixing this has a drastic effect on maximum residency for the mmark
package which goes from
```
45,005,401,056 bytes allocated in the heap
17,227,721,856 bytes copied during GC
818,281,720 bytes maximum residency (33 sample(s))
9,659,144 bytes maximum slop
2245 MiB total memory in use (0 MB lost due to fragmentation)
```
to
```
45,039,453,304 bytes allocated in the heap
13,128,181,400 bytes copied during GC
331,546,608 bytes maximum residency (40 sample(s))
7,471,120 bytes maximum slop
916 MiB total memory in use (0 MB lost due to fragmentation)
```
See #21993 for some more discussion.
- - - - -
1d17d955 by Matthew Pickering at 2022-08-26T11:13:19+01:00
Use Solo to avoid retaining the SCE but to avoid performing the substitution
The use of Solo here allows us to force the selection into the SCE to obtain
the Subst but without forcing the substitution to be applied. The resulting thunk
is placed into a lazy field which is rarely forced, so forcing it regresses
peformance.
- - - - -
25 changed files:
- .gitlab-ci.yml
- .gitlab/ci.sh
- .gitlab/upload_ghc_libs.py
- − MAKEHELP.md
- − Makefile
- − bindisttest/ghc.mk
- boot
- compiler/GHC/Cmm/CommonBlockElim.hs
- compiler/GHC/Core.hs
- compiler/GHC/Core/Lint.hs
- compiler/GHC/Core/Opt/Arity.hs
- compiler/GHC/Core/Opt/DmdAnal.hs
- compiler/GHC/Core/Opt/FloatOut.hs
- compiler/GHC/Core/Opt/SetLevels.hs
- compiler/GHC/Core/Opt/Simplify.hs
- compiler/GHC/Core/Opt/Simplify/Iteration.hs
- compiler/GHC/Core/Opt/Simplify/Utils.hs
- compiler/GHC/Core/Opt/SpecConstr.hs
- compiler/GHC/Core/Opt/WorkWrap.hs
- compiler/GHC/Core/Tidy.hs
- compiler/GHC/Core/Utils.hs
- compiler/GHC/Driver/Plugins.hs
- compiler/GHC/Iface/Tidy.hs
- compiler/GHC/SysTools/BaseDir.hs
- − compiler/Makefile
The diff was not included because it is too large.
View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/0dfaf3034ae207651b0a85a12c5cdf330f66399d...1d17d955474e8d6d6bbd4408e52cb2504c98bc3f
--
View it on GitLab: https://gitlab.haskell.org/ghc/ghc/-/compare/0dfaf3034ae207651b0a85a12c5cdf330f66399d...1d17d955474e8d6d6bbd4408e52cb2504c98bc3f
You're receiving this email because of your account on gitlab.haskell.org.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.haskell.org/pipermail/ghc-commits/attachments/20220826/8619c78c/attachment-0001.html>
More information about the ghc-commits
mailing list