<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" "http://www.w3.org/TR/REC-html40/loose.dtd">
<html lang="en">
<head>
<meta content="text/html; charset=US-ASCII" http-equiv="Content-Type">
<title>
GitLab
</title>
<style>img {
max-width: 100%; height: auto;
}
</style>
</head>
<body>
<div class="content">
<h3>
Ben Gamari pushed to branch wip/T18078
at <a href="https://gitlab.haskell.org/ghc/ghc">Glasgow Haskell Compiler / GHC</a>
</h3>
<h4>
Commits:
</h4>
<ul>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/d6279ff0841edee10a665275ed0d2402565fac6d">d6279ff0</a></strong>
<div>
<span>by Ben Gamari</span>
<i>at 2020-06-02T13:03:30-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">gitlab-ci: Ensure that workaround for #18280 applies to bindisttest
We need to ensure that the `configure` flags working around #18280 are
propagated to the bindisttest `configure` as well.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/cb5c31b51b021ce86890bba73276fe6f7405f5d3">cb5c31b5</a></strong>
<div>
<span>by Ben Gamari</span>
<i>at 2020-06-03T17:55:04-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">gitlab-ci: Allow ARMv7 job to fail
Due to #18298.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/32a4ae90b50cc56f2955f489ad0cf8c7ff5e131a">32a4ae90</a></strong>
<div>
<span>by John Ericson</span>
<i>at 2020-06-04T04:34:42-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Clean up boot vs non-boot disambiguating types
We often have (ModuleName, Bool) or (Module, Bool) pairs for "extended"
module names (without or with a unit id) disambiguating boot and normal
modules. We think this is important enough across the compiler that it
deserves a new nominal product type. We do this with synnoyms and a
functor named with a `Gen` prefix, matching other newly created
definitions.
It was also requested that we keep custom `IsBoot` / `NotBoot` sum type.
So we have it too. This means changing many the many bools to use that
instead.
Updates `haddock` submodule.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/c05756cdef800f1d8e92114222bcc480bce758b9">c05756cd</a></strong>
<div>
<span>by Niklas Hambüchen</span>
<i>at 2020-06-04T04:35:24-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">docs: Add more details on InterruptibleFFI.
Details from https://gitlab.haskell.org/ghc/ghc/issues/8684
and https://github.com/takano-akio/filelock/pull/7#discussion_r280332430
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/1b975aedb1b74b8694d14ba8fdc5955497f8f31c">1b975aed</a></strong>
<div>
<span>by Andrew Martin</span>
<i>at 2020-06-04T04:36:03-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Allow finalizeForeignPtr to be called on FinalPtr/PlainPtr.
MR 2165 (commit 49301ad6226d9a83d110bee8c419615dd94f5ded) regressed
finalizeForeignPtr by throwing exceptions when PlainPtr was encounterd.
This regression did not make it into a release of GHC. Here, the
original behavior is restored, and FinalPtr is given the same treatment
as PlainPtr.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/2bd3929ad1b06b01c1d22d513902507eefadc131">2bd3929a</a></strong>
<div>
<span>by Luke Lau</span>
<i>at 2020-06-04T04:36:41-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Fix documentation on type families not being extracted
It looks like the location of the Names used for CoAxioms on type
families are now located at their type constructors. Previously, Docs.hs
thought the Names were located in the RHS, so the RealSrcSpan in the
instanceMap and getInstLoc didn't match up. Fixes #18241
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/6735b9d94605b4c7f75e70339bfaa4207f23e52b">6735b9d9</a></strong>
<div>
<span>by Ben Gamari</span>
<i>at 2020-06-04T04:37:21-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">GHC.Hs.Instances: Compile with -O0
This module contains exclusively Data instances, which are going to be
slow no matter what we do. Furthermore, they are incredibly slow to
compile with optimisation (see #9557). Consequently we compile this with
-O0. See #18254.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/c330331adc0a686f24b94844d0eb3a0711b928d7">c330331a</a></strong>
<div>
<span>by nineonine</span>
<i>at 2020-06-04T04:37:59-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Add test for #17669
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/cab684f0857c71c40996201d6fb3ba93eb38a701">cab684f0</a></strong>
<div>
<span>by Ben Gamari</span>
<i>at 2020-06-04T04:38:36-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">rts: Add Windows-specific implementation of rtsSleep
Previously we would use the POSIX path, which uses `nanosleep`. However,
it turns out that `nanosleep` is provided by `libpthread` on Windows. In
general we don't want to incur such a dependency. Avoid this by simply
using `Sleep` on Windows.
Fixes #18272.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/ad44b50484f27beceab8213a061aa60c7a03f7ca">ad44b504</a></strong>
<div>
<span>by Ben Gamari</span>
<i>at 2020-06-04T04:38:36-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">compiler: Disable use of process jobs with process < 1.6.9
Due to #17926.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/6a4098a4bb89b3d30cca26d82b82724913062536">6a4098a4</a></strong>
<div>
<span>by Moritz Angermann</span>
<i>at 2020-06-04T04:55:51-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">[linker] Adds void printLoadedObjects(void);
This allows us to dump in-memory object code locations for debugging.
Fixup printLoadedObjects prototype
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/af5e3a885ddd09dd5f550552c535af3661ff3dbf">af5e3a88</a></strong>
<div>
<span>by Artem Pelenitsyn</span>
<i>at 2020-06-05T03:18:49-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">base: fix sign confusion in log1mexp implementation (fix #17125)
author: claude (https://gitlab.haskell.org/trac-claude)
The correct threshold for log1mexp is -(log 2) with the current specification
of log1mexp. This change improves accuracy for large negative inputs.
To avoid code duplication, a small helper function is added;
it isn't the default implementation in Floating because it needs Ord.
This patch does nothing to address that the Haskell specification is
different from that in common use in other languages.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/2b792facab46f7cdd09d12e79499f4e0dcd4293f">2b792fac</a></strong>
<div>
<span>by Simon Peyton Jones</span>
<i>at 2020-06-05T09:27:50-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Simple subsumption
This patch simplifies GHC to use simple subsumption.
Ticket #17775
Implements GHC proposal #287
https://github.com/ghc-proposals/ghc-proposals/blob/master/
proposals/0287-simplify-subsumption.rst
All the motivation is described there; I will not repeat it here.
The implementation payload:
* tcSubType and friends become noticably simpler, because it no
longer uses eta-expansion when checking subsumption.
* No deeplyInstantiate or deeplySkolemise
That in turn means that some tests fail, by design; they can all
be fixed by eta expansion. There is a list of such changes below.
Implementing the patch led me into a variety of sticky corners, so
the patch includes several othe changes, some quite significant:
* I made String wired-in, so that
"foo" :: String rather than
"foo" :: [Char]
This improves error messages, and fixes #15679
* The pattern match checker relies on knowing about in-scope equality
constraints, andd adds them to the desugarer's environment using
addTyCsDs. But the co_fn in a FunBind was missed, and for some reason
simple-subsumption ends up with dictionaries there. So I added a
call to addTyCsDs. This is really part of #18049.
* I moved the ic_telescope field out of Implication and into
ForAllSkol instead. This is a nice win; just expresses the code
much better.
* There was a bug in GHC.Tc.TyCl.Instance.tcDataFamInstHeader.
We called checkDataKindSig inside tc_kind_sig, /before/
solveEqualities and zonking. Obviously wrong, easily fixed.
* solveLocalEqualitiesX: there was a whole mess in here, around
failing fast enough. I discovered a bad latent bug where we
could successfully kind-check a type signature, and use it,
but have unsolved constraints that could fill in coercion
holes in that signature -- aargh.
It's all explained in Note [Failure in local type signatures]
in GHC.Tc.Solver. Much better now.
* I fixed a serious bug in anonymous type holes. IN
f :: Int -> (forall a. a -> _) -> Int
that "_" should be a unification variable at the /outer/
level; it cannot be instantiated to 'a'. This was plain
wrong. New fields mode_lvl and mode_holes in TcTyMode,
and auxiliary data type GHC.Tc.Gen.HsType.HoleMode.
This fixes #16292, but makes no progress towards the more
ambitious #16082
* I got sucked into an enormous refactoring of the reporting of
equality errors in GHC.Tc.Errors, especially in
mkEqErr1
mkTyVarEqErr
misMatchMsg
misMatchMsgOrCND
In particular, the very tricky mkExpectedActualMsg function
is gone.
It took me a full day. But the result is far easier to understand.
(Still not easy!) This led to various minor improvements in error
output, and an enormous number of test-case error wibbles.
One particular point: for occurs-check errors I now just say
Can't match 'a' against '[a]'
rather than using the intimidating language of "occurs check".
* Pretty-printing AbsBinds
Tests review
* Eta expansions
T11305: one eta expansion
T12082: one eta expansion (undefined)
T13585a: one eta expansion
T3102: one eta expansion
T3692: two eta expansions (tricky)
T2239: two eta expansions
T16473: one eta
determ004: two eta expansions (undefined)
annfail06: two eta (undefined)
T17923: four eta expansions (a strange program indeed!)
tcrun035: one eta expansion
* Ambiguity check at higher rank. Now that we have simple
subsumption, a type like
f :: (forall a. Eq a => Int) -> Int
is no longer ambiguous, because we could write
g :: (forall a. Eq a => Int) -> Int
g = f
and it'd typecheck just fine. But f's type is a bit
suspicious, and we might want to consider making the
ambiguity check do a check on each sub-term. Meanwhile,
these tests are accepted, whereas they were previously
rejected as ambiguous:
T7220a
T15438
T10503
T9222
* Some more interesting error message wibbles
T13381: Fine: one error (Int ~ Exp Int)
rather than two (Int ~ Exp Int, Exp Int ~ Int)
T9834: Small change in error (improvement)
T10619: Improved
T2414: Small change, due to order of unification, fine
T2534: A very simple case in which a change of unification order
means we get tow unsolved constraints instead of one
tc211: bizarre impredicative tests; just accept this for now
Updates Cabal and haddock submodules.
Metric Increase:
T12150
T12234
T5837
haddock.base
Metric Decrease:
haddock.compiler
haddock.Cabal
haddock.base
Merge note: This appears to break the
`UnliftedNewtypesDifficultUnification` test. It has been marked as
broken in the interest of merging.
(cherry picked from commit 66b7b195cb3dce93ed5078b80bf568efae904cc5)
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/bacad81aeafe410572b26da8a2de2cc412c15a06">bacad81a</a></strong>
<div>
<span>by Simon Peyton Jones</span>
<i>at 2020-06-05T10:51:18-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Optimisation in Unique.Supply
This patch switches on -fno-state-hack in GHC.Types.Unique.Supply.
It turned out that my fixes for #18078 (coercion floating) changed the
optimisation pathway for mkSplitUniqSupply in such a way that we had
an extra allocation inside the inner loop. Adding -fno-state-hack
fixed that -- and indeed the loop in mkSplitUniqSupply is a classic
example of the way in which -fno-state-hack can be bad; see #18238.
Moreover, the new code is better than the old. They allocate
the same, but the old code ends up with a partial application.
The net effect is that the test
perf/should_run/UniqLoop
runs 20% faster! From 2.5s down to 2.0s. The allocation numbers
are the same -- but elapsed time falls. Good!
The bad thing about this is that it's terribly delicate. But
at least it's a good example of such delicacy in action.
There is a long Note [Optimising the unique supply] which now
explains all this.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/867b2332e9111ce77eb44010b0f40e17180ee306">867b2332</a></strong>
<div>
<span>by Simon Peyton Jones</span>
<i>at 2020-06-05T10:51:18-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Implement cast worker/wrapper properly
The cast worker/wrapper transformation transforms
x = e |> co
into
y = e
x = y |> co
This is done by the simplifier, but we were being
careless about transferring IdInfo from x to y,
and about what to do if x is a NOINLNE function.
This resulted in a series of bugs:
#17673, #18093, #18078.
This patch fixes all that:
* Main change is in GHC.Core.Opt.Simplify, and
the new prepareBinding function, which does this
cast worker/wrapper transform.
See Note [Cast worker/wrappers].
* There is quite a bit of refactoring around
prepareRhs, makeTrivial etc. It's nicer now.
* Some wrappers from strictness and cast w/w, notably those for
a function with a NOINLINE, should inline very late. There
wasn't really a mechanism for that, which was an existing bug
really; so I invented a new finalPhase = Phase (-1). It's used
for all simplifier runs after the user-visible phase 2,1,0 have
run. (No new runs of the simplifier are introduced thereby.)
See new Note [Compiler phases] in GHC.Types.Basic;
the main changes are in GHC.Core.Opt.Driver
* Doing this made me trip over two places where the AnonArgFlag on a
FunTy was being lost so we could end up with (Num a -> ty)
rather than (Num a => ty)
- In coercionLKind/coercionRKind
- In contHoleType in the Simplifier
I fixed the former by defining mkFunctionType and using it in
coercionLKind/RKind.
I could have done the same for the latter, but the information
is almost to hand. So I fixed the latter by
- adding sc_hole_ty to ApplyToVal (like ApplyToTy),
- adding as_hole_ty to ValArg (like TyArg)
- adding sc_fun_ty to StrictArg
Turned out I could then remove ai_type from ArgInfo. This is
just moving the deck chairs around, but it worked out nicely.
See the new Note [AnonArgFlag] in GHC.Types.Var
* When looking at the 'arity decrease' thing (#18093) I discovered
that stable unfoldings had a much lower arity than the actual
optimised function. That's what led to the arity-decrease
message. Simple solution: eta-expand.
It's described in Note [Eta-expand stable unfoldings]
in GHC.Core.Opt.Simplify
* I also discovered that unsafeCoerce wasn't being inlined if
the context was boring. So (\x. f (unsafeCoerce x)) would
create a thunk -- yikes! I fixed that by making inlineBoringOK
a bit cleverer: see Note [Inline unsafeCoerce] in GHC.Core.Unfold.
I also found that unsafeCoerceName was unused, so I removed it.
I made a test case for #18078, and a very similar one for #17673.
The net effect of all this on nofib is very modest, but positive:
--------------------------------------------------------------------------------
Program Size Allocs Runtime Elapsed TotalMem
--------------------------------------------------------------------------------
anna -0.4% -0.1% -3.1% -3.1% 0.0%
fannkuch-redux -0.4% -0.3% -0.1% -0.1% 0.0%
maillist -0.4% -0.1% -7.8% -1.0% -14.3%
primetest -0.4% -15.6% -7.1% -6.6% 0.0%
--------------------------------------------------------------------------------
Min -0.9% -15.6% -13.3% -14.2% -14.3%
Max -0.3% 0.0% +12.1% +12.4% 0.0%
Geometric Mean -0.4% -0.2% -2.3% -2.2% -0.1%
Metric Decrease:
T15164
T13701
Metric Increase:
T12150
T12234
T12425
</pre>
</li>
</ul>
<h4>30 changed files:</h4>
<ul>
<li class="file-stats">
<a href="#587d266bb27a4dc3022bbed44dfa19849df3044c">
.gitlab-ci.yml
</a>
</li>
<li class="file-stats">
<a href="#d0d96a6d03668aeab20ebe05e2c4ccb798c7e64c">
compiler/GHC.hs
</a>
</li>
<li class="file-stats">
<a href="#0887cf39c5cdf9cf8d6758f410d7dab3023c0d77">
compiler/GHC/Builtin/Names.hs
</a>
</li>
<li class="file-stats">
<a href="#377cfd14c1f92357465df995ec6537b074051322">
compiler/GHC/Builtin/Types.hs
</a>
</li>
<li class="file-stats">
<a href="#783e5dae6e86931f06700fc088fb7d48c8a07386">
compiler/GHC/Core/Coercion.hs
</a>
</li>
<li class="file-stats">
<a href="#446b4afbe6836b950115a619acea24ddde19dc90">
compiler/GHC/Core/Opt/CSE.hs
</a>
</li>
<li class="file-stats">
<a href="#c1bf6b849619bc8d7ef37a97d993dbfaa9966f7b">
compiler/GHC/Core/Opt/CprAnal.hs
</a>
</li>
<li class="file-stats">
<a href="#f2f5de8b9f31451d693079c2a2d27fb47b18a3f4">
compiler/GHC/Core/Opt/Driver.hs
</a>
</li>
<li class="file-stats">
<a href="#f168a93cde5e2aec2441d6331dfe500172df4af3">
compiler/GHC/Core/Opt/Simplify.hs
</a>
</li>
<li class="file-stats">
<a href="#48fbb5cdea308650de5756521feb28ec68819b9b">
compiler/GHC/Core/Opt/Simplify/Utils.hs
</a>
</li>
<li class="file-stats">
<a href="#b6a5ba32bafb8fbda933538b3007e755fef6f101">
compiler/GHC/Core/Opt/SpecConstr.hs
</a>
</li>
<li class="file-stats">
<a href="#5b215b0e109123e4bef5434854f18e2f61c45b88">
compiler/GHC/Core/Opt/WorkWrap.hs
</a>
</li>
<li class="file-stats">
<a href="#11ffe98a94d798427bc600e4fcfe899407536346">
compiler/GHC/Core/SimpleOpt.hs
</a>
</li>
<li class="file-stats">
<a href="#84c9d3ba34173297e7d7747e02caa2e004b164fc">
compiler/GHC/Core/Type.hs
</a>
</li>
<li class="file-stats">
<a href="#2811a7297b8aa206197ac1f5dabd0818e3c7ec5a">
compiler/GHC/Core/Unfold.hs
</a>
</li>
<li class="file-stats">
<a href="#1a7aba0daeafab195716dd25432479804a55ab60">
compiler/GHC/Core/Utils.hs
</a>
</li>
<li class="file-stats">
<a href="#a5d27de4e3111a69f69902c65ecf7b3379f7c49a">
compiler/GHC/CoreToStg/Prep.hs
</a>
</li>
<li class="file-stats">
<a href="#dbce6cb5e8f3d5287103c66d1a56ad63bbbd11a9">
compiler/GHC/Driver/Backpack.hs
</a>
</li>
<li class="file-stats">
<a href="#9a679a2680ef6061397f1987091ea9f96ffe095d">
compiler/GHC/Driver/Main.hs
</a>
</li>
<li class="file-stats">
<a href="#1dab250036d04cfcf3530f6ff27889f723cc2dda">
compiler/GHC/Driver/Make.hs
</a>
</li>
<li class="file-stats">
<a href="#53557c97f676581665e366694f2931a29d6d76cd">
compiler/GHC/Driver/MakeFile.hs
</a>
</li>
<li class="file-stats">
<a href="#ff068514f65150b5ec069a421b0223fe35f41569">
compiler/GHC/Driver/Types.hs
</a>
</li>
<li class="file-stats">
<a href="#65ca06d51797ebf672a62bde6c00bcb9444e1425">
compiler/GHC/Hs/Binds.hs
</a>
</li>
<li class="file-stats">
<a href="#9c30887fc30e3c645fe9705eac50f0d8a5410c6b">
compiler/GHC/Hs/ImpExp.hs
</a>
</li>
<li class="file-stats">
<a href="#9f00edfedb0f969865b049a78de3866545b4a60b">
compiler/GHC/Hs/Instances.hs
</a>
</li>
<li class="file-stats">
<a href="#018be522bc4813b147a1525e4f96a7a493207d96">
compiler/GHC/Hs/Type.hs
</a>
</li>
<li class="file-stats">
<a href="#65e2067fbb7377818b6cadff0531f44029499948">
compiler/GHC/HsToCore/Binds.hs
</a>
</li>
<li class="file-stats">
<a href="#ea46b374e004d4416e29a563ee063542f98e48c5">
compiler/GHC/HsToCore/Docs.hs
</a>
</li>
<li class="file-stats">
<a href="#c8a27621f82549165d8946ae8e9f467660958059">
compiler/GHC/HsToCore/Monad.hs
</a>
</li>
<li class="file-stats">
<a href="#ac0a6473a902628a18b3a470122e5cc1ce09de14">
compiler/GHC/HsToCore/PmCheck.hs
</a>
</li>
</ul>
<h5>The diff was not included because it is too large.</h5>
</div>
<div class="footer" style="margin-top: 10px;">
<p style="font-size: small; color: #777;">
—
<br>
<a href="https://gitlab.haskell.org/ghc/ghc/-/compare/320ec1f370b7929d91df527ddc10c8c2e977bb7c...867b2332e9111ce77eb44010b0f40e17180ee306">View it on GitLab</a>.
<br>
You're receiving this email because of your account on gitlab.haskell.org.
If you'd like to receive fewer emails, you can
adjust your notification settings.
</p>
</div>
</body>
</html>