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<h3 style="margin-top: 20px; margin-bottom: 10px;">
Simon Peyton Jones pushed to branch wip/simplifier-tweaks 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/8a8ac65a51fd3163b4a189b427bd495bfdc61cf5">8a8ac65a</a></strong>
<div>
<span> by Matthew Craven </span> <i> at 2024-03-23T00:20:52-04:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 14px; color: #333238; position: relative; font-family: var(--default-mono-font, "GitLab Mono"),"JetBrains Mono","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;'>Improve toInteger @Word32 on 64-bit platforms
On 64-bit platforms, every Word32 fits in an Int, so we can
convert to Int# without having to perform the overflow check
integerFromWord# uses internally.
</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/0c48f2b952ad4ee995e4eafa458b7a8d3c442415">0c48f2b9</a></strong>
<div>
<span> by Apoorv Ingle </span> <i> at 2024-03-23T00:21:28-04:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 14px; color: #333238; position: relative; font-family: var(--default-mono-font, "GitLab Mono"),"JetBrains Mono","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 for #24552 (see testcase T24552)
Fixes for a bug in desugaring pattern synonyms matches, introduced
while working on on expanding `do`-blocks in #18324
The `matchWrapper` unecessarily (and incorrectly) filtered out the
default wild patterns in a match. Now the wild pattern alternative is
simply ignored by the pm check as its origin is `Generated`.
The current code now matches the expected semantics according to the language spec.
</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/b72705e9b2ae5575aef92ede6ff975bbbe43004d">b72705e9</a></strong>
<div>
<span> by Simon Peyton Jones </span> <i> at 2024-03-23T00:22:04-04:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 14px; color: #333238; position: relative; font-family: var(--default-mono-font, "GitLab Mono"),"JetBrains Mono","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;'>Print more info about kinds in error messages
This fixes #24553, where GHC unhelpfully said
error: [GHC-83865]
• Expected kind ‘* -> * -> *’, but ‘Foo’ has kind ‘* -> * -> *’
See Note [Showing invisible bits of types in error messages]
</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/8f7cfc7ee00978fda14f31ce4a56ad4639c07138">8f7cfc7e</a></strong>
<div>
<span> by Tristan Cacqueray </span> <i> at 2024-03-23T00:22:44-04:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 14px; color: #333238; position: relative; font-family: var(--default-mono-font, "GitLab Mono"),"JetBrains Mono","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;'>docs: remove the don't use float hint
This hint is outdated, ``Complex Float`` are now specialised,
and the heap space suggestion needs more nuance so it should
be explained in the unboxed/storable array documentation.
</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/5bd8ed53dcefe10b72acb5729789e19ceb22df66">5bd8ed53</a></strong>
<div>
<span> by Andreas Klebinger </span> <i> at 2024-03-23T16:18:33-04:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 14px; color: #333238; position: relative; font-family: var(--default-mono-font, "GitLab Mono"),"JetBrains Mono","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;'>NCG: Fix a bug in jump shortcutting.
When checking if a jump has more than one destination account for the
possibility of some jumps not being representable by a BlockId.
We do so by having isJumpishInstr return a `Maybe BlockId` where Nothing
represents non-BlockId jump destinations.
Fixes #24507
</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/8d67f247c3e4ca3810712654e1becbf927405f6b">8d67f247</a></strong>
<div>
<span> by Ben Gamari </span> <i> at 2024-03-23T16:19:09-04:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 14px; color: #333238; position: relative; font-family: var(--default-mono-font, "GitLab Mono"),"JetBrains Mono","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;'>docs: Drop old release notes, add for 9.12.1
</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/7db8c9927fae3369fc4ecff68f80c4cb32eea757">7db8c992</a></strong>
<div>
<span> by Cheng Shao </span> <i> at 2024-03-25T13:45:46-04:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 14px; color: #333238; position: relative; font-family: var(--default-mono-font, "GitLab Mono"),"JetBrains Mono","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;'>rts: fix clang compilation on aarch64
This patch fixes function prototypes in ARMOutlineAtomicsSymbols.h
which causes "error: address argument to atomic operation must be a
pointer to _Atomic type" when compiling with clang on aarch64.
</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/237194ceb4f227e9f69e8e6f913afa0496d2a583">237194ce</a></strong>
<div>
<span> by Sylvain Henry </span> <i> at 2024-03-25T13:46:27-04:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 14px; color: #333238; position: relative; font-family: var(--default-mono-font, "GitLab Mono"),"JetBrains Mono","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;'>Lexer: fix imports for Alex 3.5.1 (#24583)
</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/810660b780e1111b36c91326bcd0041e1f62706b">810660b7</a></strong>
<div>
<span> by Cheng Shao </span> <i> at 2024-03-25T22:19:16-04:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 14px; color: #333238; position: relative; font-family: var(--default-mono-font, "GitLab Mono"),"JetBrains Mono","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;'>libffi-tarballs: bump libffi-tarballs submodule to libffi 3.4.6
This commit bumps the libffi-tarballs submodule to libffi 3.4.6, which
includes numerous upstream libffi fixes, especially
https://github.com/libffi/libffi/issues/760.
</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/d2ba41e8c3e71d70a0f80dcc3f588ecbdc5ce4b2">d2ba41e8</a></strong>
<div>
<span> by Alan Zimmerman </span> <i> at 2024-03-25T22:19:51-04:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 14px; color: #333238; position: relative; font-family: var(--default-mono-font, "GitLab Mono"),"JetBrains Mono","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;'>EPA: do not duplicate comments in signature RHS
</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/d137121992c323704f1b715b46a75039cb8ad418">d1371219</a></strong>
<div>
<span> by Simon Peyton Jones </span> <i> at 2024-03-26T11:39:22+00:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 14px; color: #333238; position: relative; font-family: var(--default-mono-font, "GitLab Mono"),"JetBrains Mono","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;'>Several improvements to the handling of coercions
* Make `mkSymCo` and `mkInstCo` smarter
Fixes #23642
* Fix return role of `SelCo` in the coercion optimiser.
Fixes #23617
* Make the coercion optimiser `opt_trans_rule` work better for newtypes
Fixes #23619
</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/1eebfb65cc390af1d0fd7242adb8a2ea8b0c9f52">1eebfb65</a></strong>
<div>
<span> by Simon Peyton Jones </span> <i> at 2024-03-26T11:39:22+00:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 14px; color: #333238; position: relative; font-family: var(--default-mono-font, "GitLab Mono"),"JetBrains Mono","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;'>FloatOut: improve floating for join point
See the new Note [Floating join point bindings].
* Completely get rid of the complicated join_ceiling nonsense, which
I have never understood.
* Do not float join points at all, except perhaps to top level.
* Some refactoring around wantToFloat, to treat Rec and NonRec more
uniformly
</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/ccf3422200a675737f65409013cbe3efbadfadd0">ccf34222</a></strong>
<div>
<span> by Simon Peyton Jones </span> <i> at 2024-03-26T11:39:22+00:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 14px; color: #333238; position: relative; font-family: var(--default-mono-font, "GitLab Mono"),"JetBrains Mono","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;'>Improve eta-expansion through call stacks
See Note [Eta expanding through CallStacks] in GHC.Core.Opt.Arity
This is a one-line change, that fixes an inconsistency
- || isCallStackPredTy ty
+ || isCallStackPredTy ty || isCallStackTy ty
</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/1c4a2e14d14ac53b13deff57ae5afcd2fe9e5305">1c4a2e14</a></strong>
<div>
<span> by Simon Peyton Jones </span> <i> at 2024-03-26T11:39:22+00:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 14px; color: #333238; position: relative; font-family: var(--default-mono-font, "GitLab Mono"),"JetBrains Mono","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;'>Spelling, layout, pretty-printing only
</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/e5e487da83c5ed3bb69f8bf0910e8f56add996b5">e5e487da</a></strong>
<div>
<span> by Simon Peyton Jones </span> <i> at 2024-03-26T11:39:22+00:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 14px; color: #333238; position: relative; font-family: var(--default-mono-font, "GitLab Mono"),"JetBrains Mono","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;'>Improve exprIsConApp_maybe a little
Eliminate a redundant case at birth. This sometimes reduces
Simplifier iterations.
See Note [Case elim in exprIsConApp_maybe].
</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/42fd4071ea47c7aa0d0e65f70b7e30d3f815cb90">42fd4071</a></strong>
<div>
<span> by Simon Peyton Jones </span> <i> at 2024-03-26T11:39:22+00:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 14px; color: #333238; position: relative; font-family: var(--default-mono-font, "GitLab Mono"),"JetBrains Mono","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;'>Inline GHC.HsToCore.Pmc.Solver.Types.trvVarInfo
When exploring compile-time regressions after meddling with the Simplifier, I
discovered that GHC.HsToCore.Pmc.Solver.Types.trvVarInfo was very delicately
balanced. It's a small, heavily used, overloaded function and it's important
that it inlines. By a fluke it was before, but at various times in my journey it
stopped doing so. So I just added an INLINE pragma to it; no sense in depending
on a delicately-balanced fluke.
</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/5e37b4d5366e896906d7d8de9160669ab71481e4">5e37b4d5</a></strong>
<div>
<span> by Simon Peyton Jones </span> <i> at 2024-03-26T11:39:22+00:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 14px; color: #333238; position: relative; font-family: var(--default-mono-font, "GitLab Mono"),"JetBrains Mono","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;'>Slight improvement in WorkWrap
Ensure that WorkWrap preserves lambda binders, in case of join points. Sadly I
have forgotten why I made this change (it was while I was doing a lot of
meddling in the Simplifier, but
* it does no harm,
* it is slightly more efficient, and
* presumably it made something better!
Anyway I have kept it in a separate commit.
</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/d4c04c9fde327cebd79270d5d9d3de6b05482328">d4c04c9f</a></strong>
<div>
<span> by Simon Peyton Jones </span> <i> at 2024-03-26T11:39:22+00:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 14px; color: #333238; position: relative; font-family: var(--default-mono-font, "GitLab Mono"),"JetBrains Mono","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;'>Use named record fields for the CastIt { ... } data constructor
This is a pure refactor
</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/f330f0ab0f1b4a64bb53c084247cd04fd4300cbb">f330f0ab</a></strong>
<div>
<span> by Simon Peyton Jones </span> <i> at 2024-03-26T11:39:22+00:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 14px; color: #333238; position: relative; font-family: var(--default-mono-font, "GitLab Mono"),"JetBrains Mono","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 a long-commented-out line
Pure refactoring
</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/0edce85a75dff39d66d87ac3ccf5811513e1a1c7">0edce85a</a></strong>
<div>
<span> by Simon Peyton Jones </span> <i> at 2024-03-26T11:39:22+00:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 14px; color: #333238; position: relative; font-family: var(--default-mono-font, "GitLab Mono"),"JetBrains Mono","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;'>Simplifier improvements
This MR started as: allow the simplifer to do more in one pass,
arising from places I could see the simplifier taking two iterations
where one would do. But it turned into a larger project, because
these changes unexpectedly made inlining blow up, especially join
points in deeply-nested cases.
The main changes are below. There are also many new or rewritten Notes.
Avoiding simplifying repeatedly
~~~~~~~~~~~~~~~
See Note [Avoiding simplifying repeatedly]
* The SimplEnv now has a seInlineDepth field, which says how deep
in unfoldings we are. See Note [Inline depth] in Simplify.Env.
Currently used only for the next point: avoiding repeatedly
simplifying coercions.
* Avoid repeatedly simplifying coercions.
see Note [Avoid re-simplifying coercions] in Simplify.Iteration
As you'll see from the Note, this makes use of the seInlineDepth.
* Allow Simplify.Iteration.simplAuxBind to inline used-once things.
This is another part of Note [Post-inline for single-use things], and
is really good for reducing simplifier iterations in situations like
case K e of { K x -> blah }
wher x is used once in blah.
* Make GHC.Core.SimpleOpt.exprIsConApp_maybe do some simple case
elimination. Note [Case elim in exprIsConApp_maybe]
postInlineUnconditionally
~~~~~~~~~~~~~~~~~~~~~~~~~
* Allow Simplify.Utils.postInlineUnconditionally to inline variables
that are used exactly once. See Note [Post-inline for single-use things].
* Do not postInlineUnconditionally join point, ever.
Doing so does not reduce allocation, which is the main point,
and with join points that are used a lot it can bloat code.
See point (1) of Note [Duplicating join points] in
GHC.Core.Opt.Simplify.Iteration.
* Do not postInlineUnconditionally a strict (demanded) binding.
It will not allocate a thunk (it'll turn into a case instead)
so again the main point of inlining it doesn't hold. Better
to check per-call-site.
* Improve occurrence analyis for bottoming function calls, to help
postInlineUnconditionally. See Note [Bottoming function calls]
in GHC.Core.Opt.OccurAnal
Inlining generally
~~~~~~~~~~~~~~~~~~
* In GHC.Core.Opt.Simplify.Utils.interestingCallContext,
use RhsCtxt NonRecursive (not BoringCtxt) for a plain-seq case.
See Note [Seq is boring]
* In GHC.Core.Opt.Simplify.Utils.interestingArg,
- return ValueArg for OtherCon [c1,c2, ...], but
- return NonTrivArg for OtherCon []
This makes a function a little less likely to inline if all we
know is that the argument is evaluated, but nothing else.
* isConLikeUnfolding is no longer true for OtherCon {}.
This propagates to exprIsConLike. Con-like-ness has /positive/
information.
Join points
~~~~~~~~~~~
* Be very careful about inlining join points.
See these two long Notes
Note [Duplicating join points] in GHC.Core.Opt.Simplify.Iteration
Note [Inlining join points] in GHC.Core.Opt.Simplify.Inline
* When making join points, don't do so if the join point is so small
it will immediately be inlined; check uncondInlineJoin.
* In GHC.Core.Opt.Simplify.Inline.tryUnfolding, improve the inlining
heuristics for join points. In general we /do not/ want to inline
join points /even if they are small/. See Note [Duplicating join points]
GHC.Core.Opt.Simplify.Iteration.
But sometimes we do: see Note [Inlining join points] in
GHC.Core.Opt.Simplify.Inline.
* Do not add an unfolding to a join point at birth. This is a tricky one
and has a long Note [Do not add unfoldings to join points at birth]
It shows up in two places
- In `mkDupableAlt` do not add an inlining
- (trickier) In `simplLetUnfolding` don't add an unfolding for a
fresh join point
I am not fully satisifed with this, but it works and is well documented.
* In GHC.Core.Unfold.sizeExpr, make jumps small, so that we don't penalise
having a non-inlined join point.
</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/cfd5e4a170e2b33ae8d164bc59f338a74a58fa56">cfd5e4a1</a></strong>
<div>
<span> by Simon Peyton Jones </span> <i> at 2024-03-26T11:39:22+00:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 14px; color: #333238; position: relative; font-family: var(--default-mono-font, "GitLab Mono"),"JetBrains Mono","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 message changes from simplifier improvements
</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/2ee2620f9955936050b044fb1dfc2ff95f4d1671">2ee2620f</a></strong>
<div>
<span> by Simon Peyton Jones </span> <i> at 2024-03-26T11:39:22+00:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 14px; color: #333238; position: relative; font-family: var(--default-mono-font, "GitLab Mono"),"JetBrains Mono","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;'>Account for bottoming functions in OccurAnal
This fixes #24582, a small but long-standing bug
</pre>
</li>
<li>
<strong style="font-weight: bold;"><a href="https://gitlab.haskell.org/ghc/ghc/-/commit/2cf3c6e74d31c4635d5d47276042ada323523403">2cf3c6e7</a></strong>
<div>
<span> by Simon Peyton Jones </span> <i> at 2024-03-26T13:59:29+00:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 14px; color: #333238; position: relative; font-family: var(--default-mono-font, "GitLab Mono"),"JetBrains Mono","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 mergeCaseAlts to prepareAlts
This makes it happen on InAlts, which reduces the number of Simplifier
iterations by one.
</pre>
</li>
</ul>
<h4 style="margin-top: 10px; margin-bottom: 10px;">
23 changed files:
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<li class="file-stats">
<a href="#807babf5b215890881c92043bcd08486141a405c">
compiler/GHC/CmmToAsm/AArch64/Instr.hs
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<li class="file-stats">
<a href="#5986ebaacfa99d264abfd2f7ef19d99a64db720f">
compiler/GHC/CmmToAsm/BlockLayout.hs
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<li class="file-stats">
<a href="#ee14f325b8d394d681c0d3c18a3477016d1092ef">
compiler/GHC/CmmToAsm/Instr.hs
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<li class="file-stats">
<a href="#89f8a68c62e7b5e239f8d8d532820fc086d29140">
compiler/GHC/CmmToAsm/PPC/Instr.hs
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<li class="file-stats">
<a href="#3aba9ceb20d68f25343fe3a27b2b7a4f8fea68da">
compiler/GHC/CmmToAsm/Reg/Graph/SpillClean.hs
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<a href="#6b7e521fe89077442c3d86c888eb96793606049a">
compiler/GHC/CmmToAsm/Reg/Linear/JoinToTargets.hs
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<a href="#b4cadffdafb6a1f441fede8639ba742ae903afca">
compiler/GHC/CmmToAsm/Reg/Liveness.hs
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<a href="#7b360ca84c1b9aaecc0f9de207a7698dc36514fe">
compiler/GHC/CmmToAsm/X86/Instr.hs
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<a href="#182d6a315e784018aa9c8b2ad736036b97bd5d48">
compiler/GHC/Core.hs
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<a href="#783e5dae6e86931f06700fc088fb7d48c8a07386">
compiler/GHC/Core/Coercion.hs
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<a href="#975dc08a8e7942b32d621f617d5a9c1b668601dd">
compiler/GHC/Core/Coercion/Opt.hs
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<a href="#691eec62dc293d0881c314b38b7363dc88b44c59">
compiler/GHC/Core/Map/Type.hs
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<a href="#c3967bb9d3e8f5aae2dd111b5a335b48c21c1999">
compiler/GHC/Core/Opt/Arity.hs
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<a href="#0debbb6150cac3b9f1027e430021269925103bb9">
compiler/GHC/Core/Opt/FloatOut.hs
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<li class="file-stats">
<a href="#9aae8d40d1a22cf73eaec14fd86dfc6917ce10e5">
compiler/GHC/Core/Opt/Monad.hs
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<li class="file-stats">
<a href="#bac3d5159a5688007de3aa3f5c4e50569677b347">
compiler/GHC/Core/Opt/OccurAnal.hs
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<li class="file-stats">
<a href="#bd153f89bc48f3fd5079b51fb799808aacbd750c">
compiler/GHC/Core/Opt/Pipeline.hs
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<li class="file-stats">
<a href="#cc763cdd1967f5d921161a32f64136cfcf0332c5">
compiler/GHC/Core/Opt/SetLevels.hs
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<li class="file-stats">
<a href="#f168a93cde5e2aec2441d6331dfe500172df4af3">
compiler/GHC/Core/Opt/Simplify.hs
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<li class="file-stats">
<a href="#2f46b19cb85e3f7b4e72305644bc50015628c41d">
compiler/GHC/Core/Opt/Simplify/Env.hs
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<li class="file-stats">
<a href="#8664fd2691eea70244c0a1bae2f51f2ad8a36eef">
compiler/GHC/Core/Opt/Simplify/Inline.hs
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<li class="file-stats">
<a href="#ae6d91a5d028418bbf1431347d659e744e0a3128">
compiler/GHC/Core/Opt/Simplify/Iteration.hs
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<li class="file-stats">
<a href="#37879a759bc2ca5cc8f1f35235fe96e3e55b57c9">
compiler/GHC/Core/Opt/Simplify/Monad.hs
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The diff was not included because it is too large.
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