<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" "http://www.w3.org/TR/REC-html40/loose.dtd">
<html lang="en" style='--code-editor-font: var(--default-mono-font, "Menlo"), DejaVu Sans Mono, Liberation Mono, Consolas, Ubuntu Mono, Courier New, andale mono, lucida console, monospace;'>
<head>
<meta content="text/html; charset=US-ASCII" http-equiv="Content-Type">
<title>
GitLab
</title>
<style data-premailer="ignore" type="text/css">
a { color: #1068bf; }
</style>
<style>img {
max-width: 100%; height: auto;
}
body {
font-size: 0.875rem;
}
body {
-webkit-text-shadow: rgba(255,255,255,0.01) 0 0 1px;
}
body {
font-family: var(--default-regular-font, -apple-system),BlinkMacSystemFont,"Segoe UI",Roboto,"Noto Sans",Ubuntu,Cantarell,"Helvetica Neue",sans-serif,"Apple Color Emoji","Segoe UI Emoji","Segoe UI Symbol","Noto Color Emoji"; font-size: inherit;
}
</style>
</head>
<body style='font-size: inherit; -webkit-text-shadow: rgba(255,255,255,0.01) 0 0 1px; font-family: var(--default-regular-font, -apple-system),BlinkMacSystemFont,"Segoe UI",Roboto,"Noto Sans",Ubuntu,Cantarell,"Helvetica Neue",sans-serif,"Apple Color Emoji","Segoe UI Emoji","Segoe UI Symbol","Noto Color Emoji";'>
<div class="content">
<h3 style="margin-top: 20px; margin-bottom: 10px;">
Andrei Borzenkov pushed to branch wip/sand-witch/modern-STV-extension-shuffling at <a href="https://gitlab.haskell.org/ghc/ghc">Glasgow Haskell Compiler / GHC</a>
</h3>
<h4 style="margin-top: 10px; margin-bottom: 10px;">
Commits:
</h4>
<ul>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/0350b1865f392cf9590c82b5194b62e63770aa44">0350b186</a></strong>
<div>
<span> by Josh Meredith </span> <i> at 2023-05-29T12:46:27+00:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 0.875rem; color: #333238; position: relative; font-family: var(--default-mono-font, "Menlo"),"DejaVu Sans Mono","Liberation Mono","Consolas","Ubuntu Mono","Courier New","andale mono","lucida console",monospace; word-break: break-all; word-wrap: break-word; background-color: #fbfafd; border-radius: 2px; margin: 0; padding: 8px 12px; border: 1px solid #dcdcde;'>Remove JavaScriptFFI from --supported-extensions for non-JS targets (#11214)
</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/b48169194bfbfdbfd23ef4cad80212a13e262717">b4816919</a></strong>
<div>
<span> by Matthew Pickering </span> <i> at 2023-05-30T17:07:43-04:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 0.875rem; color: #333238; position: relative; font-family: var(--default-mono-font, "Menlo"),"DejaVu Sans Mono","Liberation Mono","Consolas","Ubuntu Mono","Courier New","andale mono","lucida console",monospace; word-break: break-all; word-wrap: break-word; background-color: #fbfafd; border-radius: 2px; margin: 0; padding: 8px 12px; border: 1px solid #dcdcde;'>testsuite: Pass -kb16k -kc128k for performance tests
Setting a larger stack chunk size gives a greater protection
from stack thrashing (where the repeated overflow/underflow allocates a lot of
stack chunks which sigificantly impact allocations). This
stabilises some tests against differences cause by more things being
pushed onto the stack.
The performance tests are generally testing work done by the compiler,
using allocation as a proxy, so removing/stabilising the allocations due
to the stack gives us more stable tests which are also more sensitive
to actual changes in compiler performance.
The tests which increase are ones where we compile a lot of modules, and
for each module we spawn a thread to compile the module in. Therefore
increasing these numbers has a multiplying effect on these tests because
there are many more stacks which we can increase in size.
The most significant improvements though are cases such as T8095 which
reduce significantly in allocations (30%). This isn't a performance
improvement really but just helps stabilise the test against this
threshold set by the defaults.
Fixes #23439
-------------------------
Metric Decrease:
InstanceMatching
T14683
T8095
T9872b_defer
T9872d
T9961
hie002
T19695
T3064
Metric Increase:
MultiLayerModules
T13701
T14697
-------------------------
</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/6629f1c58a714405ba94e93d54a9c471f6f62914">6629f1c5</a></strong>
<div>
<span> by Ben Gamari </span> <i> at 2023-05-30T17:08:20-04:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 0.875rem; color: #333238; position: relative; font-family: var(--default-mono-font, "Menlo"),"DejaVu Sans Mono","Liberation Mono","Consolas","Ubuntu Mono","Courier New","andale mono","lucida console",monospace; word-break: break-all; word-wrap: break-word; background-color: #fbfafd; border-radius: 2px; margin: 0; padding: 8px 12px; border: 1px solid #dcdcde;'>Move via-C flags into GHC
These were previously hardcoded in configure (with no option for
overriding them) and simply passed onto ghc through the settings file.
Since configure already guarantees gcc supports those flags, we simply
move them into GHC.
</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/981e5e11f41a11c0d58fa61faea2fe4a5ef02d00">981e5e11</a></strong>
<div>
<span> by Arnaud Spiwack </span> <i> at 2023-05-31T08:34:33-04:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 0.875rem; color: #333238; position: relative; font-family: var(--default-mono-font, "Menlo"),"DejaVu Sans Mono","Liberation Mono","Consolas","Ubuntu Mono","Courier New","andale mono","lucida console",monospace; word-break: break-all; word-wrap: break-word; background-color: #fbfafd; border-radius: 2px; margin: 0; padding: 8px 12px; border: 1px solid #dcdcde;'>Allow CPR on unrestricted constructors
Per the new `Note [Linting linearity]`, we want optimisations over
trying to preserve linearity. This will allow CPR to handle `Ur`, in
particular.
</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/bf9344d24157986ea013210e7cb9a5953670e0e2">bf9344d2</a></strong>
<div>
<span> by Arnaud Spiwack </span> <i> at 2023-05-31T08:34:33-04:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 0.875rem; color: #333238; position: relative; font-family: var(--default-mono-font, "Menlo"),"DejaVu Sans Mono","Liberation Mono","Consolas","Ubuntu Mono","Courier New","andale mono","lucida console",monospace; word-break: break-all; word-wrap: break-word; background-color: #fbfafd; border-radius: 2px; margin: 0; padding: 8px 12px; border: 1px solid #dcdcde;'>Push coercions across multiplicity boundaries
Per the new `Note [Linting linearity]`, we want optimisations over
trying to preserve linearity. This will avoid preventing inlinings and
reductions and make linear programs more efficient.
</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/d56dd6957dccb187e11155e61a113a6aea1da653">d56dd695</a></strong>
<div>
<span> by sheaf </span> <i> at 2023-05-31T11:37:12-04:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 0.875rem; color: #333238; position: relative; font-family: var(--default-mono-font, "Menlo"),"DejaVu Sans Mono","Liberation Mono","Consolas","Ubuntu Mono","Courier New","andale mono","lucida console",monospace; word-break: break-all; word-wrap: break-word; background-color: #fbfafd; border-radius: 2px; margin: 0; padding: 8px 12px; border: 1px solid #dcdcde;'>Data.Bag: add INLINEABLE to polymorphic functions
This commit allows polymorphic methods in GHC.Data.Bag to be
specialised, avoiding having to pass explicit dictionaries when they
are instantiated with e.g. a known monad.
</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/5366cd35df5522bd9a1d2897b47280925c3fcff8">5366cd35</a></strong>
<div>
<span> by sheaf </span> <i> at 2023-05-31T11:37:12-04:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 0.875rem; color: #333238; position: relative; font-family: var(--default-mono-font, "Menlo"),"DejaVu Sans Mono","Liberation Mono","Consolas","Ubuntu Mono","Courier New","andale mono","lucida console",monospace; word-break: break-all; word-wrap: break-word; background-color: #fbfafd; border-radius: 2px; margin: 0; padding: 8px 12px; border: 1px solid #dcdcde;'>Split off TcBinderStack into its own module
This commit splits off TcBinderStack into its own module,
to avoid module cycles: we might want to refer to it without also
pulling in the TcM monad.
</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/09d4d307924369ceb1e3ba056c38227f85581f34">09d4d307</a></strong>
<div>
<span> by sheaf </span> <i> at 2023-05-31T11:37:12-04:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 0.875rem; color: #333238; position: relative; font-family: var(--default-mono-font, "Menlo"),"DejaVu Sans Mono","Liberation Mono","Consolas","Ubuntu Mono","Courier New","andale mono","lucida console",monospace; word-break: break-all; word-wrap: break-word; background-color: #fbfafd; border-radius: 2px; margin: 0; padding: 8px 12px; border: 1px solid #dcdcde;'>Split off TcRef into its own module
This helps avoid pull in the full TcM monad when we just want access
to mutable references in the typechecker. This facilitates later patches
which introduce a slimmed down TcM monad for zonking.
</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/88cc19b33286398745df1b04566ebc056d48cc04">88cc19b3</a></strong>
<div>
<span> by sheaf </span> <i> at 2023-05-31T11:37:12-04:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 0.875rem; color: #333238; position: relative; font-family: var(--default-mono-font, "Menlo"),"DejaVu Sans Mono","Liberation Mono","Consolas","Ubuntu Mono","Courier New","andale mono","lucida console",monospace; word-break: break-all; word-wrap: break-word; background-color: #fbfafd; border-radius: 2px; margin: 0; padding: 8px 12px; border: 1px solid #dcdcde;'>Introduce Codensity monad
The Codensity monad is useful to write state-passing computations in
continuation-passing style, e.g. to implement a State monad as
continuation-passing style over a Reader monad.
</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/f62d81954691e1f1f4e4ac1c86b0d99bbc31cbc4">f62d8195</a></strong>
<div>
<span> by sheaf </span> <i> at 2023-05-31T11:37:12-04:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 0.875rem; color: #333238; position: relative; font-family: var(--default-mono-font, "Menlo"),"DejaVu Sans Mono","Liberation Mono","Consolas","Ubuntu Mono","Courier New","andale mono","lucida console",monospace; word-break: break-all; word-wrap: break-word; background-color: #fbfafd; border-radius: 2px; margin: 0; padding: 8px 12px; border: 1px solid #dcdcde;'>Restructure the zonker
This commit splits up the zonker into a few separate components, described
in Note [The structure of the zonker] in `GHC.Tc.Zonk.Type`.
1. `GHC.Tc.Zonk.Monad` introduces a pared-down `TcM` monad, `ZonkM`,
which has enough information for zonking types.
This allows us to refactor `ErrCtxt` to use `ZonkM` instead of `TcM`,
which guarantees we don't throw an error while reporting an error.
2. `GHC.Tc.Zonk.Env` is the new home of `ZonkEnv`, and also defines
two zonking monad transformers, `ZonkT` and `ZonkBndrT`.
`ZonkT` is a reader monad transformer over `ZonkEnv`.
`ZonkBndrT m` is the codensity monad over `ZonkT m`.
`ZonkBndrT` is used for computations that accumulate binders
in the `ZonkEnv`.
3. `GHC.Tc.Zonk.TcType` contains the code for zonking types, for use
in the typechecker. It uses the `ZonkM` monad.
4. `GHC.Tc.Zonk.Type` contains the code for final zonking to `Type`,
which has been refactored to use `ZonkTcM = ZonkT TcM` and
`ZonkBndrTcM = ZonkBndrT TcM`.
Allocations slightly decrease on the whole due to using
continuation-passing style instead of manual state passing of ZonkEnv
in the final zonking to Type.
-------------------------
Metric Decrease:
T4029
T8095
T14766
T15304
hard_hole_fits
RecordUpdPerf
Metric Increase:
T10421
-------------------------
</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/70526f5bd8886126f49833ef20604a2c6477780a">70526f5b</a></strong>
<div>
<span> by mimi.vx </span> <i> at 2023-05-31T11:37:53-04:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 0.875rem; color: #333238; position: relative; font-family: var(--default-mono-font, "Menlo"),"DejaVu Sans Mono","Liberation Mono","Consolas","Ubuntu Mono","Courier New","andale mono","lucida console",monospace; word-break: break-all; word-wrap: break-word; background-color: #fbfafd; border-radius: 2px; margin: 0; padding: 8px 12px; border: 1px solid #dcdcde;'>Update rdt-theme to latest upstream version
Fixes https://gitlab.haskell.org/ghc/ghc/-/issues/23444
</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/cc1dc1a587744b992287b56e9822af80e73290fd">cc1dc1a5</a></strong>
<div>
<span> by Andrei Borzenkov </span> <i> at 2023-06-01T06:07:38+00:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 0.875rem; color: #333238; position: relative; font-family: var(--default-mono-font, "Menlo"),"DejaVu Sans Mono","Liberation Mono","Consolas","Ubuntu Mono","Courier New","andale mono","lucida console",monospace; word-break: break-all; word-wrap: break-word; background-color: #fbfafd; border-radius: 2px; margin: 0; padding: 8px 12px; border: 1px solid #dcdcde;'>Fix -Wterm-variable-capture scope (#23434)
-Wterm-variable-capture wasn't accordant with type variable
scoping in associated types, in type classes. For example,
this code produced the warning:
k = 12
class C k a where
type AT a :: k -> Type
I solved this issue by reusing machinery of newTyVarNameRn function
that is accordand with associated types: it does lookup for each free type
variable when we are in the type class context. And in this patch I
use result of this work to make sure that -Wterm-variable-capture warns
only on implicitly quantified type variables.
</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/5dd3c909f87d5e66874da5c1fb8dacd4833bdcc7">5dd3c909</a></strong>
<div>
<span> by Andrei Borzenkov </span> <i> at 2023-06-01T06:07:38+00:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 0.875rem; color: #333238; position: relative; font-family: var(--default-mono-font, "Menlo"),"DejaVu Sans Mono","Liberation Mono","Consolas","Ubuntu Mono","Courier New","andale mono","lucida console",monospace; word-break: break-all; word-wrap: break-word; background-color: #fbfafd; border-radius: 2px; margin: 0; padding: 8px 12px; border: 1px solid #dcdcde;'>Extension shuffling (#23291)
Where introduced 4 new extensions:
- PatternSignatures
- ExtendedForAllScope
- MethodTypeVariables
- ImplicitForAll
Tasks of ScopedTypeVariables extension were distributed between
PatternSignatures, ExtendedForAllScope and MethodTypeVariables according
to the proposal. Now ScopedTypeVaribles only implies these three exntesions.
Extension ImplicitForAll saves current behavior. NoImplicitForAll
disables implicit bounding of type variables in many contexts.
Was introduced one new warning option: -Wpattern-signature-binds
It warns when pattern signature binds into scope new type variable. For
example:
f (a :: t) = ...
</pre>
</li>
</ul>
<h4 style="margin-top: 10px; margin-bottom: 10px;">
30 changed files:
</h4>
<ul>
<li class="file-stats">
<a href="#8a5cd068459120cddf3814e7b9e02003b87647ba">
compiler/GHC/Builtin/Types/Prim.hs
</a>
</li>
<li class="file-stats">
<a href="#c3967bb9d3e8f5aae2dd111b5a335b48c21c1999">
compiler/GHC/Core/Opt/Arity.hs
</a>
</li>
<li class="file-stats">
<a href="#f4421b4e35592648510c877ecf55b1af2b96dcee">
compiler/GHC/Core/Opt/WorkWrap/Utils.hs
</a>
</li>
<li class="file-stats">
<a href="#84c9d3ba34173297e7d7747e02caa2e004b164fc">
compiler/GHC/Core/Type.hs
</a>
</li>
<li class="file-stats">
<a href="#a5d27de4e3111a69f69902c65ecf7b3379f7c49a">
compiler/GHC/CoreToStg/Prep.hs
</a>
</li>
<li class="file-stats">
<a href="#2fefe3125c649bc5377b06a7cca18e785855b79c">
compiler/GHC/Data/Bag.hs
</a>
</li>
<li class="file-stats">
<a href="#c7ca3e6f50c136f058ec179bdb3fbb3cc19a7b42">
compiler/GHC/Data/IOEnv.hs
</a>
</li>
<li class="file-stats">
<a href="#e65e7bbfc24f8830a20082bfc50f6d16e613cbeb">
compiler/GHC/Driver/DynFlags.hs
</a>
</li>
<li class="file-stats">
<a href="#2e5692f568fd7b67a6b172e2a60469da8392508c">
compiler/GHC/Driver/Flags.hs
</a>
</li>
<li class="file-stats">
<a href="#9a679a2680ef6061397f1987091ea9f96ffe095d">
compiler/GHC/Driver/Main.hs
</a>
</li>
<li class="file-stats">
<a href="#774d88050336ef660c7a219fb06c480c2fc639bc">
compiler/GHC/Driver/Session.hs
</a>
</li>
<li class="file-stats">
<a href="#018be522bc4813b147a1525e4f96a7a493207d96">
compiler/GHC/Hs/Type.hs
</a>
</li>
<li class="file-stats">
<a href="#7a1af22e4c32b9aa6ec708d9d3788e1c4db5da9a">
compiler/GHC/Hs/Utils.hs
</a>
</li>
<li class="file-stats">
<a href="#65e2067fbb7377818b6cadff0531f44029499948">
compiler/GHC/HsToCore/Binds.hs
</a>
</li>
<li class="file-stats">
<a href="#6bdd5abc649727f2a802bc96ce5c276de19d3726">
compiler/GHC/HsToCore/Expr.hs
</a>
</li>
<li class="file-stats">
<a href="#f017e4c978a9ff341ce5a7b838787fd2a4758b59">
compiler/GHC/HsToCore/Match/Literal.hs
</a>
</li>
<li class="file-stats">
<a href="#950eaa7de202a2e915b5ff68a4cfd16e972ad359">
compiler/GHC/HsToCore/Pmc/Desugar.hs
</a>
</li>
<li class="file-stats">
<a href="#af762064d779f7308dd415966c974f27d14f9943">
compiler/GHC/Rename/Bind.hs
</a>
</li>
<li class="file-stats">
<a href="#86d694037d496c511e28b2c09c8410f67dc19596">
compiler/GHC/Rename/Env.hs
</a>
</li>
<li class="file-stats">
<a href="#b47ece2bbb8303a5792c2fdc52394c8ed336e8a2">
compiler/GHC/Rename/Expr.hs
</a>
</li>
<li class="file-stats">
<a href="#892acbb198a9095c917740d3c1297b56df4e3b7e">
compiler/GHC/Rename/HsType.hs
</a>
</li>
<li class="file-stats">
<a href="#7dd1cd0f6f2164a14c83d9aa564dd32bc30e447a">
compiler/GHC/Rename/Module.hs
</a>
</li>
<li class="file-stats">
<a href="#e05ee69330b0f7088f11a5f3567137547489664d">
compiler/GHC/Rename/Names.hs
</a>
</li>
<li class="file-stats">
<a href="#cfa41b5649933e5b12f7796e9d49b9dd6a0bc59f">
compiler/GHC/Rename/Pat.hs
</a>
</li>
<li class="file-stats">
<a href="#16b273b96a1c03d4261e2ac6de4cc456ba2dd014">
compiler/GHC/Rename/Splice.hs
</a>
</li>
<li class="file-stats">
<a href="#173c7eb846a4e9b5fee79688a72cbf6a326e4e1e">
compiler/GHC/Runtime/Eval.hs
</a>
</li>
<li class="file-stats">
<a href="#8858278b4cb7284f96b29b5564bcb426de4fae70">
compiler/GHC/Runtime/Heap/Inspect.hs
</a>
</li>
<li class="file-stats">
<a href="#6740fa77d6598a0ef908509264d676d65ab31fd1">
compiler/GHC/Settings/IO.hs
</a>
</li>
<li class="file-stats">
<a href="#b768fdf8e0594bf98104ef18145fc9f16550bc06">
compiler/GHC/Tc/Deriv.hs
</a>
</li>
<li class="file-stats">
<a href="#3aa56839e36b2219f9ad54f5646ef3005da9c672">
compiler/GHC/Tc/Deriv/Generate.hs
</a>
</li>
</ul>
<h5 style="margin-top: 10px; margin-bottom: 10px; font-size: 0.875rem;">
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: #737278;">
—
<br>
<a href="https://gitlab.haskell.org/ghc/ghc/-/compare/a47e341d524a104c6f81260bf478bbc4c9ec52a0...5dd3c909f87d5e66874da5c1fb8dacd4833bdcc7">View it on GitLab</a>.
<br>
You're receiving this email because of your account on <a target="_blank" rel="noopener noreferrer" href="https://gitlab.haskell.org">gitlab.haskell.org</a>. <a href="https://gitlab.haskell.org/-/profile/notifications" target="_blank" rel="noopener noreferrer" class="mng-notif-link">Manage all notifications</a> · <a href="https://gitlab.haskell.org/help" target="_blank" rel="noopener noreferrer" class="help-link">Help</a>
</p>
</div>
</body>
</html>