<!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: GitLab Mono, JetBrains Mono, 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: "GitLab Sans", -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: "GitLab Sans", -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;">
Marge Bot pushed to branch master 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/d03698023891b9d474915ad1cccdef8c8ba78e78">d0369802</a></strong>
<div>
<span> by Simon Peyton Jones </span> <i> at 2023-07-30T09:24:48+01:00 </i>
</div>
<pre class="commit-message" style='white-space: pre-wrap; display: block; font-size: 14px; color: #333238; position: relative; font-family: "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;'>Make the occurrence analyser smarter about join points
This MR addresses #22404. There is a big Note
Note [Occurrence analysis for join points]
that explains it all. Significant changes
* New field occ_join_points in OccEnv
* The NonRec case of occAnalBind splits into two cases:
one for existing join points (which does the special magic for
Note [Occurrence analysis for join points], and one for other
bindings.
* mkOneOcc adds in info from occ_join_points.
* All "bring into scope" activity is centralised in the
new function `addInScope`.
* I made a local data type LocalOcc for use inside the occurrence analyser
It is like OccInfo, but lacks IAmDead and IAmALoopBreaker, which in turn
makes computationns over it simpler and more efficient.
* I found quite a bit of allocation in GHC.Core.Rules.getRules
so I optimised it a bit.
More minor changes
* I found I was using (Maybe Arity) a lot, so I defined a new data
type JoinPointHood and used it everwhere. This touches a lot of
non-occ-anal files, but it makes everything more perspicuous.
* Renamed data constructor WithUsageDetails to WUD, and
WithTailUsageDetails to WTUD
This also fixes #21128, on the way.
--------- Compiler perf -----------
I spent quite a time on performance tuning, so even though it
does more than before, the occurrence analyser runs slightly faster
on average. Here are the compile-time allocation changes over 0.5%
CoOpt_Read(normal) ghc/alloc 766,025,520 754,561,992 -1.5%
CoOpt_Singletons(normal) ghc/alloc 759,436,840 762,925,512 +0.5%
LargeRecord(normal) ghc/alloc 1,814,482,440 1,799,530,456 -0.8%
PmSeriesT(normal) ghc/alloc 68,159,272 67,519,720 -0.9%
T10858(normal) ghc/alloc 120,805,224 118,746,968 -1.7%
T11374(normal) ghc/alloc 164,901,104 164,070,624 -0.5%
T11545(normal) ghc/alloc 79,851,808 78,964,704 -1.1%
T12150(optasm) ghc/alloc 73,903,664 71,237,544 -3.6% GOOD
T12227(normal) ghc/alloc 333,663,200 331,625,864 -0.6%
T12234(optasm) ghc/alloc 52,583,224 52,340,344 -0.5%
T12425(optasm) ghc/alloc 81,943,216 81,566,720 -0.5%
T13056(optasm) ghc/alloc 294,517,928 289,642,512 -1.7%
T13253-spj(normal) ghc/alloc 118,271,264 59,859,040 -49.4% GOOD
T15164(normal) ghc/alloc 1,102,630,352 1,091,841,296 -1.0%
T15304(normal) ghc/alloc 1,196,084,000 1,166,733,000 -2.5%
T15630(normal) ghc/alloc 148,729,632 147,261,064 -1.0%
T15703(normal) ghc/alloc 379,366,664 377,600,008 -0.5%
T16875(normal) ghc/alloc 32,907,120 32,670,976 -0.7%
T17516(normal) ghc/alloc 1,658,001,888 1,627,863,848 -1.8%
T17836(normal) ghc/alloc 395,329,400 393,080,248 -0.6%
T18140(normal) ghc/alloc 71,968,824 73,243,040 +1.8%
T18223(normal) ghc/alloc 456,852,568 453,059,088 -0.8%
T18282(normal) ghc/alloc 129,105,576 131,397,064 +1.8%
T18304(normal) ghc/alloc 71,311,712 70,722,720 -0.8%
T18698a(normal) ghc/alloc 208,795,112 210,102,904 +0.6%
T18698b(normal) ghc/alloc 230,320,736 232,697,976 +1.0% BAD
T19695(normal) ghc/alloc 1,483,648,128 1,504,702,976 +1.4%
T20049(normal) ghc/alloc 85,612,024 85,114,376 -0.6%
T21839c(normal) ghc/alloc 415,080,992 410,906,216 -1.0% GOOD
T4801(normal) ghc/alloc 247,590,920 250,726,272 +1.3%
T6048(optasm) ghc/alloc 95,699,416 95,080,680 -0.6%
T783(normal) ghc/alloc 335,323,384 332,988,120 -0.7%
T9233(normal) ghc/alloc 709,641,224 685,947,008 -3.3% GOOD
T9630(normal) ghc/alloc 965,635,712 948,356,120 -1.8%
T9675(optasm) ghc/alloc 444,604,152 428,987,216 -3.5% GOOD
T9961(normal) ghc/alloc 303,064,592 308,798,800 +1.9% BAD
WWRec(normal) ghc/alloc 503,728,832 498,102,272 -1.1%
geo. mean -1.0%
minimum -49.4%
maximum +1.9%
In fact these figures seem to vary between platforms; generally worse
on i386 for some reason. The Windows numbers vary by 1% espec in
benchmarks where the total allocation is low. But the geom mean stays
solidly negative, which is good. The "increase/decrease" list below
covers all platforms.
The big win on T13253-spj comes because it has a big nest of join
points, each occurring twice in the next one. The new occ-anal takes
only one iteration of the simplifier to do the inlining; the old one
took four. Moreover, we get much smaller code with the new one:
New: Result size of Tidy Core
= {terms: 429, types: 84, coercions: 0, joins: 14/14}
Old: Result size of Tidy Core
= {terms: 2,437, types: 304, coercions: 0, joins: 10/10}
--------- Runtime perf -----------
No significant changes in nofib results, except a 1% reduction in
compiler allocation.
Metric Decrease:
CoOpt_Read
T13253-spj
T9233
T9630
T9675
T12150
T21839c
LargeRecord
MultiComponentModulesRecomp
T10421
T13701
T10421
T13701
T12425
Metric Increase:
T18140
T9961
T18282
T18698a
T18698b
T19695
</pre>
</li>
</ul>
<h4 style="margin-top: 10px; margin-bottom: 10px;">
30 changed files:
</h4>
<ul>
<li class="file-stats">
<a href="#36a42448a83a9d1f6df8475f03ead2eed199dd8e">
compiler/GHC/Core/Lint.hs
</a>
</li>
<li class="file-stats">
<a href="#446b4afbe6836b950115a619acea24ddde19dc90">
compiler/GHC/Core/Opt/CSE.hs
</a>
</li>
<li class="file-stats">
<a href="#8104fa1b71db6cfc4eb90cd769463d9eb9004619">
compiler/GHC/Core/Opt/DmdAnal.hs
</a>
</li>
<li class="file-stats">
<a href="#1b8c4a0d06e2de704f7d040a0a715345e0c3c78c">
compiler/GHC/Core/Opt/Exitify.hs
</a>
</li>
<li class="file-stats">
<a href="#09072575aca2480de8c1966011972c529575ba5d">
compiler/GHC/Core/Opt/FloatIn.hs
</a>
</li>
<li class="file-stats">
<a href="#0debbb6150cac3b9f1027e430021269925103bb9">
compiler/GHC/Core/Opt/FloatOut.hs
</a>
</li>
<li class="file-stats">
<a href="#bac3d5159a5688007de3aa3f5c4e50569677b347">
compiler/GHC/Core/Opt/OccurAnal.hs
</a>
</li>
<li class="file-stats">
<a href="#cc763cdd1967f5d921161a32f64136cfcf0332c5">
compiler/GHC/Core/Opt/SetLevels.hs
</a>
</li>
<li class="file-stats">
<a href="#2f46b19cb85e3f7b4e72305644bc50015628c41d">
compiler/GHC/Core/Opt/Simplify/Env.hs
</a>
</li>
<li class="file-stats">
<a href="#ae6d91a5d028418bbf1431347d659e744e0a3128">
compiler/GHC/Core/Opt/Simplify/Iteration.hs
</a>
</li>
<li class="file-stats">
<a href="#b6a5ba32bafb8fbda933538b3007e755fef6f101">
compiler/GHC/Core/Opt/SpecConstr.hs
</a>
</li>
<li class="file-stats">
<a href="#5b215b0e109123e4bef5434854f18e2f61c45b88">
compiler/GHC/Core/Opt/WorkWrap.hs
</a>
</li>
<li class="file-stats">
<a href="#a8e2a1e5829eb3b4809201e0f47e91b64ce11b96">
compiler/GHC/Core/Ppr.hs
</a>
</li>
<li class="file-stats">
<a href="#d01de95d8c71d4dec6a9a59146186e29a5b3fd38">
compiler/GHC/Core/Rules.hs
</a>
</li>
<li class="file-stats">
<a href="#11ffe98a94d798427bc600e4fcfe899407536346">
compiler/GHC/Core/SimpleOpt.hs
</a>
</li>
<li class="file-stats">
<a href="#846e2566b022c9a12a5978ac7934d5b019fbea5c">
compiler/GHC/Core/Tidy.hs
</a>
</li>
<li class="file-stats">
<a href="#2811a7297b8aa206197ac1f5dabd0818e3c7ec5a">
compiler/GHC/Core/Unfold.hs
</a>
</li>
<li class="file-stats">
<a href="#940913dd549c6b1c334daafbc4b7eef29c94d924">
compiler/GHC/Core/Unfold/Make.hs
</a>
</li>
<li class="file-stats">
<a href="#bbf06eb5d4f0db7bc3213b84b9f5822710ff7be8">
compiler/GHC/CoreToIface.hs
</a>
</li>
<li class="file-stats">
<a href="#a5d27de4e3111a69f69902c65ecf7b3379f7c49a">
compiler/GHC/CoreToStg/Prep.hs
</a>
</li>
<li class="file-stats">
<a href="#079d6b28856775716c78fdd4a4b35bb45a59002c">
compiler/GHC/Iface/Syntax.hs
</a>
</li>
<li class="file-stats">
<a href="#06ff7bac58fd8cfe0c17b81963b03f4cce86a065">
compiler/GHC/IfaceToCore.hs
</a>
</li>
<li class="file-stats">
<a href="#395cb654293c1fc577e034de4856683f093cc356">
compiler/GHC/Stg/Lint.hs
</a>
</li>
<li class="file-stats">
<a href="#166e3514d27c63ef7e86af29830d9e8b2a31c8b1">
compiler/GHC/Types/Basic.hs
</a>
</li>
<li class="file-stats">
<a href="#20aaf8344f379f354fe31dd0c1c4db4ddc5b17aa">
compiler/GHC/Types/Id.hs
</a>
</li>
<li class="file-stats">
<a href="#5dac619989e8509003cf7b463c100f5cc56072a3">
compiler/GHC/Types/Var.hs
</a>
</li>
<li class="file-stats">
<a href="#f35faa85de2e0a75cdaa452eb7336a09c677d450">
compiler/GHC/Utils/Binary.hs
</a>
</li>
<li class="file-stats">
<a href="#d3cf57b6a5ebc234dc7689db38ef9b6cf2259c0f">
compiler/GHC/Utils/Outputable.hs
</a>
</li>
<li class="file-stats">
<a href="#f372319bf89b684020e6948b714e03ca4fa68ffd">
<span class="new-file">
+
testsuite/tests/simplCore/should_compile/T22404.hs
</span>
</a>
</li>
<li class="file-stats">
<a href="#179ba24d93c6b0a7e656e41605d55f9e54471f13">
<span class="new-file">
+
testsuite/tests/simplCore/should_compile/T22404.stderr
</span>
</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/-/commit/d03698023891b9d474915ad1cccdef8c8ba78e78">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>
<script type="application/ld+json">{"@context":"http://schema.org","@type":"EmailMessage","action":{"@type":"ViewAction","name":"View Commit","url":"https://gitlab.haskell.org/ghc/ghc/-/commit/d03698023891b9d474915ad1cccdef8c8ba78e78"}}</script>
</p>
</div>
</body>
</html>