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<h3>
Ben Gamari pushed to branch wip/T15304
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/818b3c38e7548f4720815f76969238d82c9650f7">818b3c38</a></strong>
<div>
<span>by Lysxia</span>
<i>at 2020-03-16T23:52:42-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">base: add strict IO functions: readFile', getContents', hGetContents'
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/18a346a4b5a02b8c62e8eedb91b35c2d8e754b96">18a346a4</a></strong>
<div>
<span>by Sylvain Henry</span>
<i>at 2020-03-16T23:53:24-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Modules: Core (#13009)
Update submodule: haddock
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/92327e3afd9d2650c9cc9610297d40c2712da085">92327e3a</a></strong>
<div>
<span>by Ömer Sinan Ağacan</span>
<i>at 2020-03-16T23:54:04-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Update sanity checking for TSOs:
- Remove an invalid assumption about GC checking what_next field. The GC
doesn't care about what_next at all, if a TSO is reachable then all
its pointers are followed (other than global_tso, which is only
followed by compacting GC).
- Remove checkSTACK in checkTSO: TSO stacks will be visited in
checkHeapChain, or checkLargeObjects etc.
- Add an assertion in checkTSO to check that the global_link field is
sane.
- Did some refactor to remove forward decls in checkGlobalTSOList and
added braces around single-statement if statements.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/e1aa40525ddac370766907a49682976e2ea78422">e1aa4052</a></strong>
<div>
<span>by PHO</span>
<i>at 2020-03-17T07:36:09-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Don't use non-portable operator "==" in configure.ac
The test operator "==" is a Bash extension and produces a wrong result
if /bin/sh is not Bash.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/89f034ddeb4ad7d93c877d5bdbcf2cca7a44f79c">89f034dd</a></strong>
<div>
<span>by Maximilian Tagher</span>
<i>at 2020-03-17T07:36:48-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Document the units of -ddump-timings
Right now, in the output of -ddump-timings to a file, you can't tell what the units are:
```
CodeGen [TemplateTestImports]: alloc=22454880 time=14.597
```
I believe bytes/milliseconds are the correct units, but confirmation would be appreciated. I'm basing it off of this snippet from `withTiming'`:
```
when (verbosity dflags >= 2 && prtimings == PrintTimings)
$ liftIO $ logInfo dflags (defaultUserStyle dflags)
(text "!!!" <+> what <> colon <+> text "finished in"
<+> doublePrec 2 time
<+> text "milliseconds"
<> comma
<+> text "allocated"
<+> doublePrec 3 (realToFrac alloc / 1024 / 1024)
<+> text "megabytes")
```
which implies time is in milliseconds, and allocations in bytes (which divided by 1024 would be KB, and again would be MB)
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/beffa14771ebd6ba24b20337f29045364621c5fa">beffa147</a></strong>
<div>
<span>by Simon Peyton Jones</span>
<i>at 2020-03-17T07:37:25-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Implement mapTyCo like foldTyCo
This patch makes mapType use the successful idiom described
in TyCoRep
Note [Specialising foldType]
I have not yet changed any functions to use mapType, though there
may be some suitable candidates.
This patch should be a no-op in terms of functionality but,
because it inlines the mapper itself, I'm hoping that there may
be some modest perf improvements.
Metric Decrease:
T5631
T5642
T3064
T9020
T14683
hie002
haddock.Cabal
haddock.base
haddock.compiler
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/5800ebfeb2fe3e3ed985cdf08a66defea73db71d">5800ebfe</a></strong>
<div>
<span>by Ömer Sinan Ağacan</span>
<i>at 2020-03-17T07:38:08-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Don't update ModDetails with CafInfos when opts are disabled
This is consistent with the interface file behavior where we omit
HsNoCafRefs annotations with -fomit-interface-pragmas (implied by -O0).
ModDetails and ModIface are just different representations of the same
thing, so they really need to be in sync. This patch does the right
thing and does not need too much explanation, but here's an example of a
problem not doing this causes in !2842:
-- MyInteger.hs
module MyInteger
( MyInteger (MyInteger)
, ToMyInteger (toMyInteger)
) where
newtype MyInteger = MyInteger Integer
class ToMyInteger a where
toMyInteger :: a -> MyInteger
instance ToMyInteger Integer where
toMyInteger = MyInteger {- . succ -}
-- Main.hs
module Main
( main
) where
import MyInteger (MyInteger (MyInteger), toMyInteger)
main :: IO ()
main = do
let (MyInteger i) = (id . toMyInteger) (41 :: Integer)
print i
If I build this with -O0, without this fix, we generate a ModDetails with
accurate LFInfo for toMyInteger (MyInteger.$fToMyIntegerInteger) which says that
it's a LFReEntrant with arity 1. This means in the use site (Main) we tag the
value:
R3 = MyInteger.$fToMyIntegerInteger_closure + 1;
R2 = GHC.Base.id_closure;
R1 = GHC.Base.._closure;
Sp = Sp - 16;
call stg_ap_ppp_fast(R4, R3, R2, R1) args: 24, res: 0, upd: 24;
Now we change the definition by uncommenting the `succ` part and it becomes a thunk:
MyInteger.$fToMyIntegerInteger [InlPrag=INLINE (sat-args=0)]
:: MyInteger.ToMyInteger GHC.Integer.Type.Integer
[GblId[DFunId(nt)]] =
{} \u [] $ctoMyInteger_rEA;
and its LFInfo is now LFThunk. This change in LFInfo makes a difference in the
use site: we can no longer tag it.
But becuase the interface fingerprint does not change (because ModIface does not
change) we don't rebuild Main and tag the thunk.
(1.2% increase in allocations when building T12545 on armv7 because we
generate more code without CafInfos)
Metric Increase:
T12545
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/5b632dad2e1d373606fe29f7eee0daf15641560f">5b632dad</a></strong>
<div>
<span>by Paavo</span>
<i>at 2020-03-17T07:38:48-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Add example for Data.Semigroup.diff
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/4d85d68b004a3d577c0e27d9e6fdddd118e8a9f3">4d85d68b</a></strong>
<div>
<span>by Paavo</span>
<i>at 2020-03-17T07:38:48-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Clean up
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/75168d07c9c30289709423fc184bbab8dcad0f4e">75168d07</a></strong>
<div>
<span>by Paavo</span>
<i>at 2020-03-17T07:38:48-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Make example collapsible
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/53ff2cd0c49735e8f709ac8a5ceab68483eb89df">53ff2cd0</a></strong>
<div>
<span>by Richard Eisenberg</span>
<i>at 2020-03-17T13:46:57+00:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Fix #17021 by checking more return kinds
All the details are in new Note [Datatype return kinds] in
TcTyClsDecls.
Test case: typecheck/should_fail/T17021{,b}
typecheck/should_compile/T17021a
Updates haddock submodule
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/528df8ecb4e2f9c78b1ae4ab7ff8230644e9b643">528df8ec</a></strong>
<div>
<span>by Sylvain Henry</span>
<i>at 2020-03-18T10:06:43-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Modules: Core operations (#13009)
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/4e8a71c1138b587dfbab8a1823b3f7fa6f0166bd">4e8a71c1</a></strong>
<div>
<span>by Richard Eisenberg</span>
<i>at 2020-03-18T10:07:19-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Add release note about fix to #16502.
We thought we needed to update the manual, but the fix for #16502
actually brings the implementation in line with the manual. So we
just alert users of how to update their code.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/5cbf9934c59f7726781cc4cccf4748a5c09c4997">5cbf9934</a></strong>
<div>
<span>by Andreas Klebinger</span>
<i>at 2020-03-19T00:39:27-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Update "GHC differences to the FFI Chapter" in user guide.
The old entry had a heavy focus on how things had been. Which is
not what I generally look for in a user guide.
I also added a small section on behaviour of nested safe ffi calls.
[skip-ci]
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/b03fd3bcd4ff14aed2942275c3b0db5392dc913c">b03fd3bc</a></strong>
<div>
<span>by Sebastian Graf</span>
<i>at 2020-03-19T00:40:06-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">PmCheck: Use ConLikeSet to model negative info
In #17911, Simon recognised many warnings stemming from over-long list
unions while coverage checking Cabal's `LicenseId` module.
This patch introduces a new `PmAltConSet` type which uses a `UniqDSet`
instead of an association list for `ConLike`s. For `PmLit`s, it will
still use an assocation list, though, because a similar map data
structure would entail a lot of busy work.
Fixes #17911.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/64f207566931469648e791df4f0f0384d45cddd0">64f20756</a></strong>
<div>
<span>by Sylvain Henry</span>
<i>at 2020-03-19T12:16:49-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Refactoring: use Platform instead of DynFlags when possible
Metric Decrease:
ManyConstructors
T12707
T13035
T1969
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/cb1785d9f839e34a3a4892f354f0c51cc6553c0e">cb1785d9</a></strong>
<div>
<span>by Ömer Sinan Ağacan</span>
<i>at 2020-03-19T12:16:54-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">FastString: fix eager reading of string ptr in hashStr
This read causes NULL dereferencing when len is 0.
Fixes #17909
In the reproducer in #17909 this bug is triggered as follows:
- SimplOpt.dealWithStringLiteral is called with a single-char string
("=" in #17909)
- tailFS gets called on the FastString of the single-char string.
- tailFS checks the length of the string, which is 1, and calls
mkFastStringByteString on the tail of the ByteString, which is an
empty ByteString as the original ByteString has only one char.
- ByteString's unsafeUseAsCStringLen returns (NULL, 0) for the empty
ByteString, which is passed to mkFastStringWith.
- mkFastStringWith gets hash of the NULL pointer via hashStr, which
fails on empty strings because of this bug.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/73a7383ebc17f495d7acd04007c8c56b46532cb6">73a7383e</a></strong>
<div>
<span>by Richard Eisenberg</span>
<i>at 2020-03-20T20:42:56-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Simplify treatment of heterogeneous equality
Previously, if we had a [W] (a :: k1) ~ (rhs :: k2), we would
spit out a [D] k1 ~ k2 and part the W as irreducible, hoping for
a unification. But we needn't do this. Instead, we now spit out
a [W] co :: k2 ~ k1 and then use co to cast the rhs of the original
Wanted. This means that we retain the connection between the
spat-out constraint and the original.
The problem with this new approach is that we cannot use the
casted equality for substitution; it's too like wanteds-rewriting-
wanteds. So, we forbid CTyEqCans that mention coercion holes.
All the details are in Note [Equalities with incompatible kinds]
in TcCanonical.
There are a few knock-on effects, documented where they occur.
While debugging an error in this patch, Simon and I ran into
infelicities in how patterns and matches are printed; we made
small improvements.
This patch includes mitigations for #17828, which causes spurious
pattern-match warnings. When #17828 is fixed, these lines should
be removed.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/faa36e5b3674a7b2cfc6b931eec27b3558fad33b">faa36e5b</a></strong>
<div>
<span>by Sylvain Henry</span>
<i>at 2020-03-20T20:43:41-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Hadrian: ignore in-tree GMP objects with ``--lint``
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/9a96ff6b1c19c9d0af9c9a39fb2c086f311c7239">9a96ff6b</a></strong>
<div>
<span>by Richard Eisenberg</span>
<i>at 2020-03-20T20:44:17-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Update core spec to reflect changes to Core.
Key changes:
* Adds a new rule for forall-coercions over coercion variables, which
was implemented but conspicuously missing from the spec.
* Adds treatment for FunCo.
* Adds treatment for ForAllTy over coercion variables.
* Improves commentary (including restoring a Note lost in
03d4852658e1b7407abb4da84b1b03bfa6f6db3b) in the source.
No changes to running code.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/7e0451c6ce78b08b5f7564aa03a9a86051b35163">7e0451c6</a></strong>
<div>
<span>by Sergej Jaskiewicz</span>
<i>at 2020-03-20T20:44:55-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Fix event message in withTiming'
This typo caused generating 'end' events without the corresponding 'begin' events.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/1542a626a3649e5fc1becec1eff2715a6108d144">1542a626</a></strong>
<div>
<span>by Ben Gamari</span>
<i>at 2020-03-22T22:37:47-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">fs.h: Add missing declarations on Windows
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/3bcf2ccdd0bdd3cf176943ddb946e4fcef2ac7c1">3bcf2ccd</a></strong>
<div>
<span>by Ben Gamari</span>
<i>at 2020-03-22T22:37:47-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Bump process submodule
Avoids redundant case alternative warning.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/3b363ef9405c52369b63fc167ded8a533c6a5079">3b363ef9</a></strong>
<div>
<span>by Ben Gamari</span>
<i>at 2020-03-22T22:37:47-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">testsuite: Normalize slashes in ghc-api annotations output
Enable `normalise_slashes` on `annotations`, `listcomps`, and
`parseTree` to fix Windows failures.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/25fc94295c68620c6928751aaadc46b11a185f0c">25fc9429</a></strong>
<div>
<span>by Ben Gamari</span>
<i>at 2020-03-22T22:37:47-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">testsuite: Update expected output on Windows
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/7f58ec6d94f49cf5713757710c6b80a682ee066b">7f58ec6d</a></strong>
<div>
<span>by Ben Gamari</span>
<i>at 2020-03-22T22:37:47-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">testsuite: Fix TOP of T17786
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/aadcd909563d5ddf7b2fc469ee3c09c301b1a813">aadcd909</a></strong>
<div>
<span>by GHC GitLab CI</span>
<i>at 2020-03-22T22:37:47-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">testsuite: Update expected output on Windows
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/dc1eb10dae03f3fe5f11de845c6772c229684c28">dc1eb10d</a></strong>
<div>
<span>by GHC GitLab CI</span>
<i>at 2020-03-22T22:37:47-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">hadrian: Fix executable extension passed to testsuite driver
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/58f62e2caa19e13082807da1d49f94e9cf869322">58f62e2c</a></strong>
<div>
<span>by GHC GitLab CI</span>
<i>at 2020-03-22T22:37:47-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">gitlab-ci: Require that Windows-hadrian job passes
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/8dd2415dd2f423688f33a8fb267857e3ff39754d">8dd2415d</a></strong>
<div>
<span>by Ben Gamari</span>
<i>at 2020-03-22T22:37:47-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">hadrian: Eliminate redundant .exe from GHC path
Previously we were invoking:
bash -c
"c:/GitLabRunner/builds/eEQrxK4p/0/ghc/ghc/toolchain/bin/ghc.exe.exe
testsuite/mk/ghc-config.hs -o _build/test/bin/ghc-config.exe"
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/373621f61f812accdeba39c745eb7d015430ff8e">373621f6</a></strong>
<div>
<span>by Ben Gamari</span>
<i>at 2020-03-22T22:37:47-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Bump hsc2hs submodule
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/abc02b4036c2d8efe50b720d8c8103c4f1b8899a">abc02b40</a></strong>
<div>
<span>by Hécate</span>
<i>at 2020-03-22T22:38:33-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Annotate the non-total function in Data.Foldable as such
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/19f125578247dfe8036b5793cb3f6b684474f9c7">19f12557</a></strong>
<div>
<span>by Josef Svenningsson</span>
<i>at 2020-03-23T14:05:33-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Fix ApplicativeDo regression #17835
A previous fix for #15344 made sure that monadic 'fail' is used properly
when translating ApplicativeDo. However, it didn't properly account
for when a 'fail' will be inserted which resulted in some programs
failing with a type error.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/2643ba465cd2a133b6f495f34fc59cd1a6d23525">2643ba46</a></strong>
<div>
<span>by Paavo</span>
<i>at 2020-03-24T08:31:32-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Add example and doc for Arg (Fixes #17153)
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/703221f408b023a1b3433938572e7b5c24b4af60">703221f4</a></strong>
<div>
<span>by Roland Senn</span>
<i>at 2020-03-25T14:45:04-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Use export list of Main module in function TcRnDriver.hs:check_main (Fix #16453)
- Provide the export list of the `Main` module as parameter to the
`compiler/typecheck/TcRnDriver.hs:check_main` function.
- Instead of `lookupOccRn_maybe` call the function `lookupInfoOccRn`.
It returns the list `mains_all` of all the main functions in scope.
- Select from this list `mains_all` all `main` functions that are in
the export list of the `Main` module.
- If this new list contains exactly one single `main` function, then
typechecking continues.
- Otherwise issue an appropriate error message.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/3e27205a66b06a4501d87eb31e285eadbc693eb7">3e27205a</a></strong>
<div>
<span>by Sebastian Graf</span>
<i>at 2020-03-25T14:45:40-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Remove -fkill-absence and -fkill-one-shot flags
They seem to be a benchmarking vestige of the Cardinality paper and
probably shouldn't have been merged to HEAD in the first place.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/262e42aa34c4d5705c8d011907c351497dd4e862">262e42aa</a></strong>
<div>
<span>by Peter Trommler</span>
<i>at 2020-03-25T22:41:39-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Do not panic on linker errors
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/0de03cd78729dc58a846c64b645e71057ec5d24e">0de03cd7</a></strong>
<div>
<span>by Sylvain Henry</span>
<i>at 2020-03-25T22:42:02-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">DynFlags refactoring III
Use Platform instead of DynFlags when possible:
* `tARGET_MIN_INT` et al. replaced with `platformMinInt` et al.
* no more DynFlags in PreRules: added a new `RuleOpts` datatype
* don't use `wORD_SIZE` in the compiler
* make `wordAlignment` use `Platform`
* make `dOUBLE_SIZE` a constant
Metric Decrease:
T13035
T1969
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/7a04920b23376b2759b5049820400ddd40f7b89e">7a04920b</a></strong>
<div>
<span>by Tristan Cacqueray</span>
<i>at 2020-03-25T22:42:06-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Base: fix a typo in liftA doc
This change removes an extra '|' that should not be rendered in
the liftA documentation.
Tracking: #17929
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/1c5a15f7d257d0a2ded4850e38b6174965a7735b">1c5a15f7</a></strong>
<div>
<span>by Tristan Cacqueray</span>
<i>at 2020-03-25T22:42:06-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Base: add Control.Applicative optional example
This change adds an optional example.
Tracking: #17929
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/6d172e63f3dd3590b0a57371efb8f924f1fcdf05">6d172e63</a></strong>
<div>
<span>by Tristan Cacqueray</span>
<i>at 2020-03-25T22:42:06-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Base: add markup around Except
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/eb2162c81964b3a1057c21c73574cc2b542d863a">eb2162c8</a></strong>
<div>
<span>by John Ericson</span>
<i>at 2020-03-26T12:37:08-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Remove unused `ghciTablesNextToCode` from compiler proper
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/f51efc4bf5f20d1df3d11a2bb4c147f416367ae4">f51efc4b</a></strong>
<div>
<span>by Joachim Breitner</span>
<i>at 2020-03-26T12:37:09-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Prepare to use run-time tablesNextToCode in compiler exclusively
Factor out CPP as much as possible to prepare for runtime
determinattion.
Progress towards #15548
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/1c446220250dcada51d4bb33a0cc7d8ce572e8b6">1c446220</a></strong>
<div>
<span>by Joachim Breitner</span>
<i>at 2020-03-26T12:37:09-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Use run-time tablesNextToCode in compiler exclusively (#15548)
Summary:
- There is no more use of the TABLES_NEXT_TO_CODE CPP macro in
`compiler/`. GHCI_TABLES_NEXT_TO_CODE is also removed entirely.
The field within `PlatformMisc` within `DynFlags` is used instead.
- The field is still not exposed as a CLI flag. We might consider some
way to ensure the right RTS / libraries are used before doing that.
Original reviewers:
Original subscribers: TerrorJack, rwbarton, carter
Original Differential Revision: https://phabricator.haskell.org/D5082
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/1941ef4f050c0dfcb68229641fcbbde3a10f1072">1941ef4f</a></strong>
<div>
<span>by Sylvain Henry</span>
<i>at 2020-03-29T17:28:51-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Modules: Types (#13009)
Update Haddock submodule
Metric Increase:
haddock.compiler
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/1c7c6f1afc8e7f7ba5d256780bc9d5bb5f3e7601">1c7c6f1a</a></strong>
<div>
<span>by Sylvain Henry</span>
<i>at 2020-03-29T17:28:51-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Remove GHC.Types.Unique.Map module
This module isn't used anywhere in GHC.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/f1a6c73d01912b389e012a0af81a5c2002e82636">f1a6c73d</a></strong>
<div>
<span>by Sylvain Henry</span>
<i>at 2020-03-29T17:28:51-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Merge GHC.Types.CostCentre.Init into GHC.Driver.CodeOutput
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/54250f2d8de910b094070c1b48f086030df634b1">54250f2d</a></strong>
<div>
<span>by Simon Peyton Jones</span>
<i>at 2020-03-29T17:29:30-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Demand analysis: simplify the demand for a RHS
Ticket #17932 showed that we were using a stupid demand for the RHS
of a let-binding, when the result is a product. This was the result
of a "fix" in 2013, which (happily) turns out to no longer be
necessary.
So I just deleted the code, which simplifies the demand analyser,
and fixes #17932. That in turn uncovered that the anticipation
of worker/wrapper in CPR analysis was inaccurate, hence the logic
that decides whether to unbox an argument in WW was extracted into
a function `wantToUnbox`, now consulted by CPR analysis.
I tried nofib, and got 0.0% perf changes.
All this came up when messing about with !2873 (ticket #17917),
but is idependent of it.
Unfortunately, this patch regresses #4267 and realised that it is now
blocked on #16335.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/03060b2f963436dd22582f3a1c218b7a74d302ec">03060b2f</a></strong>
<div>
<span>by Ben Gamari</span>
<i>at 2020-03-29T17:30:05-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">testsuite: Fix T17786 on Windows
Fixes line ending normalization issue.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/1f7995baaaf4dcba9b3abaddcd571ac66675ab19">1f7995ba</a></strong>
<div>
<span>by Ben Gamari</span>
<i>at 2020-03-29T17:30:05-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">testsuite: Fix T17786
Fix missing quoting and expected exit code.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/ef9c608eba417c59fe45c9edd6a946c59f50b5d2">ef9c608e</a></strong>
<div>
<span>by Ben Gamari</span>
<i>at 2020-03-29T17:30:05-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">testsuite: Mark T12971 as broken on Windows
Due to #17945.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/e54500c12de051cb9695728d27c812e5160593ee">e54500c1</a></strong>
<div>
<span>by Sylvain Henry</span>
<i>at 2020-03-29T17:30:47-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Store ComponentId details
As far as GHC is concerned, installed package components ("units") are
identified by an opaque ComponentId string provided by Cabal. But we
don't want to display it to users (as it contains a hash) so GHC queries
the database to retrieve some infos about the original source package
(name, version, component name).
This patch caches these infos in the ComponentId itself so that we don't
need to provide DynFlags (which contains installed package informations)
to print a ComponentId.
In the future we want GHC to support several independent package states
(e.g. for plugins and for target code), hence we need to avoid
implicitly querying a single global package state.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/7e7cb714173652165b8372c3450f4ccd6a377497">7e7cb714</a></strong>
<div>
<span>by Marius Bakke</span>
<i>at 2020-03-29T17:31:27-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">testsuite: Remove test that dlopens a PIE object.
glibc 2.30 disallowed dlopening PIE objects, so just remove the test.
Fixes #17952.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/6c8f80d8876965539571d37d3c7f0fee43c300d2">6c8f80d8</a></strong>
<div>
<span>by Andreas Klebinger</span>
<i>at 2020-03-29T17:32:04-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Correct haddocks for testBit in Data.Bits
It conflated the nth bit with the bit at offset n.
Now we instead give the definition in terms of `bit and `.&.`
on top of clearer phrasing.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/c916f190b455d9c43459f81c7ee06d06ab3db957">c916f190</a></strong>
<div>
<span>by Andreas Klebinger</span>
<i>at 2020-03-29T17:32:04-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Apply suggestion to libraries/base/Data/Bits.hs</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/64bf7f51064dad9c63728ac8bccdb9cf00bdb420">64bf7f51</a></strong>
<div>
<span>by Ben Gamari</span>
<i>at 2020-03-29T17:32:41-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">gitlab-ci: Add FreeBSD release job
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/a0d8e92e9c9b67426aa139d6bc46363d8940f992">a0d8e92e</a></strong>
<div>
<span>by Ryan Scott</span>
<i>at 2020-03-29T17:33:20-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Run checkNewDataCon before constraint-solving newtype constructors
Within `checkValidDataCon`, we used to run `checkValidType` on the
argument types of a newtype constructor before running
`checkNewDataCon`, which ensures that the user does not attempt
non-sensical things such as newtypes with multiple arguments or
constraints. This works out in most situations, but this falls over
on a corner case revealed in #17955:
```hs
newtype T = Coercible () T => T ()
```
`checkValidType`, among other things, peforms an ambiguity check on
the context of a data constructor, and that it turn invokes the
constraint solver. It turns out that there is a special case in the
constraint solver for representational equalities (read: `Coercible`
constraints) that causes newtypes to be unwrapped (see
`Note [Unwrap newtypes first]` in `TcCanonical`). This special case
does not know how to cope with an ill formed newtype like `T`, so
it ends up panicking.
The solution is surprisingly simple: just invoke `checkNewDataCon`
before `checkValidType` to ensure that the illicit newtype
constructor context is detected before the constraint solver can
run amok with it.
Fixes #17955.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/45eb9d8cad254440eaea25676d6788ca13baa2fb">45eb9d8c</a></strong>
<div>
<span>by Krzysztof Gogolewski</span>
<i>at 2020-03-29T17:33:59-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Minor cleanup
- Simplify mkBuildExpr, the function newTyVars was called
only on a one-element list.
- TTG: use noExtCon in more places. This is more future-proof.
- In zonkExpr, panic instead of printing a warning.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/f024b6e385bd1448968b7bf20de05f655c815bae">f024b6e3</a></strong>
<div>
<span>by Sylvain Henry</span>
<i>at 2020-03-30T12:48:39+02:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Expect T4267 to pass
Since 54250f2d8de910b094070c1b48f086030df634b1 we expected T4267 to
fail, but it passes on CI.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/57b888c0e90be7189285a6b078c30b26d0923809">57b888c0</a></strong>
<div>
<span>by Ryan Scott</span>
<i>at 2020-03-31T10:54:20-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Require GHC 8.8 as the minimum compiler for bootstrapping
This allows us to remove several bits of CPP that are either always
true or no longer reachable. As an added bonus, we no longer need to
worry about importing `Control.Monad.Fail.fail` qualified to avoid
clashing with `Control.Monad.fail`, since the latter is now the same
as the former.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/33f095511a8fce4c945bbcd4feb3910c854dcb61">33f09551</a></strong>
<div>
<span>by Ryan Scott</span>
<i>at 2020-03-31T10:54:57-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Add regression test for #17963
The panic in #17963 happened to be fixed by commit
e3c374cc5bd7eb49649b9f507f9f7740697e3f70. This patch adds a
regression test to ensure that it remains fixed.
Fixes #17963.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/09a36e80ecaefcfb60eccda98bd06461d0aeca70">09a36e80</a></strong>
<div>
<span>by Ömer Sinan Ağacan</span>
<i>at 2020-03-31T10:55:37-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Simplify stderrSupportsAnsiColors
The combinator andM is used only once, and the code is shorter and
simpler if you inline it.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/95bccdd034ce4dd2d1bc36db9f1ba5e172550249">95bccdd0</a></strong>
<div>
<span>by Ben Gamari</span>
<i>at 2020-03-31T10:56:19-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">base: Ensure that encoding global variables aren't inlined
As noted in #17970, these (e.g. `getFileSystemEncoding` and
`setFileSystemEncoding`) previously had unfoldings, which would
break their global-ness.
While not strictly necessary, I also add a NOINLINE on
`initLocaleEncoding` since it is used in `System.IO`, ensuring that we
only system's query the locale encoding once.
Fixes #17970.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/982aaa837aed564ae9b418cda8e97d4facff8fb8">982aaa83</a></strong>
<div>
<span>by Andreas Klebinger</span>
<i>at 2020-03-31T10:56:55-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Update hadrian index revision.
Required in order to build hadrian using ghc-8.10
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/4b9c586472bf99425f7bbcf346472d7c54f05028">4b9c5864</a></strong>
<div>
<span>by Ben Gamari</span>
<i>at 2020-03-31T10:57:32-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">integer-gmp: Bump version and add changelog entry
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/9b39f2e6f63ae50cedd96eaf49146de8ed00fbc8">9b39f2e6</a></strong>
<div>
<span>by Ryan Scott</span>
<i>at 2020-04-01T01:20:00-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Clean up "Eta reduction for data families" Notes
Before, there were two distinct Notes named
"Eta reduction for data families". This renames one of them to
"Implementing eta reduction for data families" to disambiguate the
two and fixes references in other parts of the codebase to ensure
that they are pointing to the right place.
Fixes #17313.
[ci skip]
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/7627eab5dd882eb6f1567e3ae95c6c770830a5eb">7627eab5</a></strong>
<div>
<span>by Ryan Scott</span>
<i>at 2020-04-01T01:20:38-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Fix the changelog/@since information for hGetContents'/getContents'/readFile'
Fixes #17979.
[ci skip]
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/0002db1bf436cbd32f97b659a52b1eee4e8b21db">0002db1b</a></strong>
<div>
<span>by Sylvain Henry</span>
<i>at 2020-04-01T01:21:27-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Kill wORDS_BIGENDIAN and replace it with platformByteOrder (#17957)
Metric Decrease:
T13035
T1969
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/7b21717907a741b56513f5e1fa1ebceecf971613">7b217179</a></strong>
<div>
<span>by Sebastian Graf</span>
<i>at 2020-04-01T15:03:24-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">PmCheck: Adjust recursion depth for inhabitation test
In #17977, we ran into the reduction depth limit of the typechecker.
That was only a symptom of a much broader issue: The recursion depth
of the coverage checker for trying to instantiate strict fields in the
`nonVoid` test was far too high (100, the `defaultMaxTcBound`).
As a result, we were performing quite poorly on `T17977`.
Short of a proper termination analysis to prove emptyness of a type,
we just arbitrarily default to a much lower recursion limit of 3.
Fixes #17977.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/3c09f636a459f50119bfbb5bf798b9a9e19eb464">3c09f636</a></strong>
<div>
<span>by Andreas Klebinger</span>
<i>at 2020-04-01T15:03:59-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Make hadrian pass on the no-colour setting to GHC.
Fixes #17983.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/b943b25d0786da64031ac63ddf9b4574182057bb">b943b25d</a></strong>
<div>
<span>by Simon Peyton Jones</span>
<i>at 2020-04-02T01:45:58-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Re-engineer the binder-swap transformation
The binder-swap transformation is implemented by the occurrence
analyser -- see Note [Binder swap] in OccurAnal. However it had
a very nasty corner in it, for the case where the case scrutinee
was a GlobalId. This led to trouble and hacks, and ultimately
to #16296.
This patch re-engineers how the occurrence analyser implements
the binder-swap, by actually carrying out a substitution rather
than by adding a let-binding. It's all described in
Note [The binder-swap substitution].
I did a few other things along the way
* Fix a bug in StgCse, which could allow a loop breaker to be CSE'd
away. See Note [Care with loop breakers] in StgCse. I think it can
only show up if occurrence analyser sets up bad loop breakers, but
still.
* Better commenting in SimplUtils.prepareAlts
* A little refactoring in CoreUnfold; nothing significant
e.g. rename CoreUnfold.mkTopUnfolding to mkFinalUnfolding
* Renamed CoreSyn.isFragileUnfolding to hasCoreUnfolding
* Move mkRuleInfo to CoreFVs
We observed respectively 4.6% and 5.9% allocation decreases for the following
tests:
Metric Decrease:
T9961
haddock.base
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/42d68364f66846969edf029f878875c10cdfe0b2">42d68364</a></strong>
<div>
<span>by Sebastian Graf</span>
<i>at 2020-04-02T01:46:34-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Preserve precise exceptions in strictness analysis
Fix #13380 and #17676 by
1. Changing `raiseIO#` to have `topDiv` instead of `botDiv`
2. Give it special treatment in `Simplifier.Util.mkArgInfo`, treating it
as if it still had `botDiv`, to recover dead code elimination.
This is the first commit of the plan outlined in
https://gitlab.haskell.org/ghc/ghc/-/merge_requests/2525#note_260886.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/0a88dd11594b8d8fd20500d026e657a5f99dfdd2">0a88dd11</a></strong>
<div>
<span>by Ömer Sinan Ağacan</span>
<i>at 2020-04-02T01:47:25-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Fix a pointer format string in RTS
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/5beac042b995b055a66bc16be536d9e920f6864d">5beac042</a></strong>
<div>
<span>by Ömer Sinan Ağacan</span>
<i>at 2020-04-02T01:48:05-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Remove unused closure stg_IND_direct
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/88f38b03025386f0f1e8f5861eed67d80495168a">88f38b03</a></strong>
<div>
<span>by Ben Gamari</span>
<i>at 2020-04-02T01:48:42-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Session: Memoize stderrSupportsAnsiColors
Not only is this a reasonable efficiency measure but it avoids making
reentrant calls into ncurses, which is not thread-safe. See #17922.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/27740f24cb70fc14b00c1212c06642a144a6117d">27740f24</a></strong>
<div>
<span>by Ryan Scott</span>
<i>at 2020-04-02T01:49:21-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Make Hadrian build with Cabal-3.2
GHC 8.10 ships with `Cabal-3.2.0.0`, so it would be convenient to
make Hadrian supporting building against 3.2.* instead of having to
rebuild the entirety of `Cabal-3.0.0.0`. There is one API change in
`Cabal-3.2.*` that affects Hadrian: the `synopsis` and `description`
functions now return `ShortText` instead of `String`. Since Hadrian
manipulates these `String`s in various places, I found that the
simplest fix was to use CPP to convert `ShortText` to `String`s
where appropriate.
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/4980200255dabf59ae537f10c55d19ef1a00bbdd">49802002</a></strong>
<div>
<span>by Sylvain Henry</span>
<i>at 2020-04-02T01:50:00-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Update Stack resolver for hadrian/build-stack
Broken by 57b888c0e90be7189285a6b078c30b26d0923809
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/30a63e79c65b023497af4fe2347149382c71829d">30a63e79</a></strong>
<div>
<span>by Ryan Scott</span>
<i>at 2020-04-02T01:50:36-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Fix two ASSERT buglets in reifyDataCon
Two `ASSERT`s in `reifyDataCon` were always using `arg_tys`, but
`arg_tys` is not meaningful for GADT constructors. In fact, it's
worse than non-meaningful, since using `arg_tys` when reifying a
GADT constructor can lead to failed `ASSERT`ions, as #17305
demonstrates.
This patch applies the simplest possible fix to the immediate
problem. The `ASSERT`s now use `r_arg_tys` instead of `arg_tys`, as
the former makes sure to give something meaningful for GADT
constructors. This makes the panic go away at the very least. There
is still an underlying issue with the way the internals of
`reifyDataCon` work, as described in
https://gitlab.haskell.org/ghc/ghc/issues/17305#note_227023, but we
leave that as future work, since fixing the underlying issue is
much trickier (see
https://gitlab.haskell.org/ghc/ghc/issues/17305#note_227087).
</pre>
</li>
<li>
<strong><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/1001a085d08de5c3b7dbe338946228bb0cd446c7">1001a085</a></strong>
<div>
<span>by Ben Gamari</span>
<i>at 2020-04-02T16:12:19-04:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">simplifier: Kill off ufKeenessFactor
We used to have another factor, ufKeenessFactor, which would scale the
discounts before they were subtracted from the size. This was justified
with the following comment:
-- We multiple the raw discounts (args_discount and result_discount)
-- ty opt_UnfoldingKeenessFactor because the former have to do with
-- *size* whereas the discounts imply that there's some extra
-- *efficiency* to be gained (e.g. beta reductions, case reductions)
-- by inlining.
However, this is highly suspect since it means that we subtract a
*scaled* size from an absolute size, resulting in crazy (e.g. negative)
scores in some cases (#15304). We consequently killed off
ufKeenessFactor and bumped up the ufUseThreshold to compensate.
Adjustment of unfolding use threshold
=====================================
Since this removes a discount from our inlining heuristic, I revisited our
default choice of -funfolding-use-threshold to minimize the change in
overall inlining behavior. Specifically, I measured runtime allocations
and executable size of nofib and the testsuite performance tests built
using compilers (and core libraries) built with several values of
-funfolding-use-threshold.
This comes as a result of a quantitative comparison of testsuite
performance and code size as a function of ufUseThreshold, comparing
GHC trees using values of 50, 60, 70, 80, 90, and 100. The test set
consisted of nofib and the testsuite performance tests.
A full summary of these measurements are found in the description of
!2608
Comparing executable sizes (relative to the base commit) across all
nofib tests, we see that sizes are similar to the baseline:
gmean min max median
thresh
50 -6.36% -7.04% -4.82% -6.46%
60 -5.04% -5.97% -3.83% -5.11%
70 -2.90% -3.84% -2.31% -2.92%
80 -0.75% -2.16% -0.42% -0.73%
90 +0.24% -0.41% +0.55% +0.26%
100 +1.36% +0.80% +1.64% +1.37%
baseline +0.00% +0.00% +0.00% +0.00%
Likewise, looking at runtime allocations we see that 80 gives slightly
better optimisation than the baseline:
gmean min max median
thresh
50 +0.16% -0.16% +4.43% +0.00%
60 +0.09% -0.00% +3.10% +0.00%
70 +0.04% -0.09% +2.29% +0.00%
80 +0.02% -1.17% +2.29% +0.00%
90 -0.02% -2.59% +1.86% +0.00%
100 +0.00% -2.59% +7.51% -0.00%
baseline +0.00% +0.00% +0.00% +0.00%
Metric Decrease:
T12234
T13035
T13719
T14683
T4801
T5631
T9020
T9961
Metric Increase:
T14697
T15426
T1969
T5837
T9203
T9872a
T9872b
T9872c
T9872d
</pre>
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<a href="#587d266bb27a4dc3022bbed44dfa19849df3044c">
.gitlab-ci.yml
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<a href="#d0d96a6d03668aeab20ebe05e2c4ccb798c7e64c">
compiler/GHC.hs
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compiler/GHC/ByteCode/Asm.hs
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compiler/GHC/ByteCode/InfoTable.hs
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compiler/GHC/ByteCode/Instr.hs
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compiler/GHC/ByteCode/Linker.hs
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compiler/GHC/ByteCode/Types.hs
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compiler/GHC/Cmm.hs
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compiler/GHC/Cmm/BlockId.hs
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compiler/GHC/Cmm/CallConv.hs
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compiler/GHC/Cmm/Info/Build.hs
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compiler/GHC/Cmm/LayoutStack.hs
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compiler/GHC/Cmm/Lexer.x
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compiler/GHC/Cmm/Lint.hs
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compiler/GHC/Cmm/MachOp.hs
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compiler/GHC/Cmm/Node.hs
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compiler/GHC/Cmm/Opt.hs
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compiler/GHC/Cmm/Parser.y
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compiler/GHC/Cmm/Pipeline.hs
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compiler/GHC/Cmm/Ppr.hs
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<h5>The diff was not included because it is too large.</h5>
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