<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" "http://www.w3.org/TR/REC-html40/loose.dtd">
<html lang="en">
<head>
<meta content="text/html; charset=US-ASCII" http-equiv="Content-Type">
<title>
GitLab
</title>
<style>img {
max-width: 100%; height: auto;
}
</style>
</head>
<body>
<div class="content">
<h3>
Richard Eisenberg pushed to branch wip/cfuneqcan-refactor
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/2b7af3cd500bb587736ff455645fb4cd5ff986f3">2b7af3cd</a></strong>
<div>
<span>by Richard Eisenberg</span>
<i>at 2020-11-24T22:50:54+00:00</i>
</div>
<pre class="commit-message" style="white-space: pre-wrap; margin: 0;">Comment that intermediate cached values do not help
</pre>
</li>
</ul>
<h4>1 changed file:</h4>
<ul>
<li class="file-stats">
<a href="#528aacc312e31d522c6e47247763aedb807caeec">
compiler/GHC/Tc/Solver/Rewrite.hs
</a>
</li>
</ul>
<h4>Changes:</h4>
<li id="528aacc312e31d522c6e47247763aedb807caeec">
<a href="https://gitlab.haskell.org/ghc/ghc/-/commit/2b7af3cd500bb587736ff455645fb4cd5ff986f3#528aacc312e31d522c6e47247763aedb807caeec"><strong>compiler/GHC/Tc/Solver/Rewrite.hs</strong></a>
<hr>
<table class="code white" style="font-family: monospace; font-size: 90%;" bgcolor="#fff" width="100%" cellpadding="0" cellspacing="0">
<tr class="line_holder match" id="" style="line-height: 1.6;">
<td class="diff-line-num unfold js-unfold old_line" data-linenumber="832" style="width: 35px; color: rgba(0,0,0,0.3); border-right-width: 1px; border-right-color: #f0f0f0; border-right-style: solid; padding: 0 5px;" align="right" bgcolor="#fafafa">...</td>
<td class="diff-line-num unfold js-unfold new_line" data-linenumber="832" style="width: 35px; color: rgba(0,0,0,0.3); border-right-width: 1px; border-right-color: #f0f0f0; border-right-style: solid; padding: 0 5px;" align="right" bgcolor="#fafafa">...</td>
<td class="line_content match " style="padding-left: 0.5em; padding-right: 0.5em; color: rgba(0,0,0,0.3);" bgcolor="#fafafa">@@ -832,6 +832,9 @@ rewrite_exact_fam_app tc tys</td>
</tr>
<tr class="line_holder" id="" style="line-height: 1.6;">
<td class="diff-line-num old_line" data-linenumber="832" style="width: 35px; color: rgba(0,0,0,0.3); border-right-width: 1px; border-right-color: #f0f0f0; border-right-style: solid; padding: 0 5px;" align="right" bgcolor="#fafafa">
832
</td>
<td class="diff-line-num new_line" data-linenumber="832" style="width: 35px; color: rgba(0,0,0,0.3); border-right-width: 1px; border-right-color: #f0f0f0; border-right-style: solid; padding: 0 5px;" align="right" bgcolor="#fafafa">
832
</td>
<td class="line_content" style="padding-left: 0.5em; padding-right: 0.5em;">
<pre style="margin: 0;"> <span id="LC832" class="line" lang="haskell"> <span class="kr" style="font-weight: 600;">do</span> <span class="p">{</span> <span class="n" style="color: #333;">result3</span> <span class="o" style="font-weight: 600;"><-</span> <span class="n" style="color: #333;">try_to_reduce</span> <span class="n" style="color: #333;">tc</span> <span class="n" style="color: #333;">xis</span></span>
</pre>
</td>
</tr>
<tr class="line_holder" id="" style="line-height: 1.6;">
<td class="diff-line-num old_line" data-linenumber="833" style="width: 35px; color: rgba(0,0,0,0.3); border-right-width: 1px; border-right-color: #f0f0f0; border-right-style: solid; padding: 0 5px;" align="right" bgcolor="#fafafa">
833
</td>
<td class="diff-line-num new_line" data-linenumber="833" style="width: 35px; color: rgba(0,0,0,0.3); border-right-width: 1px; border-right-color: #f0f0f0; border-right-style: solid; padding: 0 5px;" align="right" bgcolor="#fafafa">
833
</td>
<td class="line_content" style="padding-left: 0.5em; padding-right: 0.5em;">
<pre style="margin: 0;"> <span id="LC833" class="line" lang="haskell"> <span class="p">;</span> <span class="kr" style="font-weight: 600;">case</span> <span class="n" style="color: #333;">result3</span> <span class="kr" style="font-weight: 600;">of</span></span>
</pre>
</td>
</tr>
<tr class="line_holder" id="" style="line-height: 1.6;">
<td class="diff-line-num old_line" data-linenumber="834" style="width: 35px; color: rgba(0,0,0,0.3); border-right-width: 1px; border-right-color: #f0f0f0; border-right-style: solid; padding: 0 5px;" align="right" bgcolor="#fafafa">
834
</td>
<td class="diff-line-num new_line" data-linenumber="834" style="width: 35px; color: rgba(0,0,0,0.3); border-right-width: 1px; border-right-color: #f0f0f0; border-right-style: solid; padding: 0 5px;" align="right" bgcolor="#fafafa">
834
</td>
<td class="line_content" style="padding-left: 0.5em; padding-right: 0.5em;">
<pre style="margin: 0;"> <span id="LC834" class="line" lang="haskell"> <span class="kt" style="color: #458; font-weight: 600;">Just</span> <span class="p">(</span><span class="n" style="color: #333;">co</span><span class="p">,</span> <span class="n" style="color: #333;">xi</span><span class="p">)</span> <span class="o" style="font-weight: 600;">-></span> <span class="n" style="color: #333;">finish</span> <span class="kt" style="color: #458; font-weight: 600;">True</span> <span class="p">(</span><span class="n" style="color: #333;">homogenise</span> <span class="n" style="color: #333;">xi</span> <span class="n" style="color: #333;">co</span><span class="p">)</span></span>
</pre>
</td>
</tr>
<tr class="line_holder new" id="" style="line-height: 1.6;">
<td class="diff-line-num new old_line" data-linenumber="835" style="width: 35px; color: rgba(0,0,0,0.3); border-right-width: 1px; border-right-color: #c7f0d2; border-right-style: solid; padding: 0 5px;" align="right" bgcolor="#ddfbe6">
</td>
<td class="diff-line-num new new_line" data-linenumber="835" style="width: 35px; color: rgba(0,0,0,0.3); border-right-width: 1px; border-right-color: #c7f0d2; border-right-style: solid; padding: 0 5px;" align="right" bgcolor="#ddfbe6">
835
</td>
<td class="line_content new" style="padding-left: 0.5em; padding-right: 0.5em;" bgcolor="#ecfdf0">
<pre style="margin: 0;">+<span id="LC835" class="line" lang="haskell"> <span class="c1" style="color: #998; font-style: italic;">-- We could add an item to the cache relating F xis to the final result,</span></span>
</pre>
</td>
</tr>
<tr class="line_holder new" id="" style="line-height: 1.6;">
<td class="diff-line-num new old_line" data-linenumber="835" style="width: 35px; color: rgba(0,0,0,0.3); border-right-width: 1px; border-right-color: #c7f0d2; border-right-style: solid; padding: 0 5px;" align="right" bgcolor="#ddfbe6">
</td>
<td class="diff-line-num new new_line" data-linenumber="836" style="width: 35px; color: rgba(0,0,0,0.3); border-right-width: 1px; border-right-color: #c7f0d2; border-right-style: solid; padding: 0 5px;" align="right" bgcolor="#ddfbe6">
836
</td>
<td class="line_content new" style="padding-left: 0.5em; padding-right: 0.5em;" bgcolor="#ecfdf0">
<pre style="margin: 0;">+<span id="LC836" class="line" lang="haskell"> <span class="c1" style="color: #998; font-style: italic;">-- where xis is the result of STEP 3. But testing showed that this</span></span>
</pre>
</td>
</tr>
<tr class="line_holder new" id="" style="line-height: 1.6;">
<td class="diff-line-num new old_line" data-linenumber="835" style="width: 35px; color: rgba(0,0,0,0.3); border-right-width: 1px; border-right-color: #c7f0d2; border-right-style: solid; padding: 0 5px;" align="right" bgcolor="#ddfbe6">
</td>
<td class="diff-line-num new new_line" data-linenumber="837" style="width: 35px; color: rgba(0,0,0,0.3); border-right-width: 1px; border-right-color: #c7f0d2; border-right-style: solid; padding: 0 5px;" align="right" bgcolor="#ddfbe6">
837
</td>
<td class="line_content new" style="padding-left: 0.5em; padding-right: 0.5em;" bgcolor="#ecfdf0">
<pre style="margin: 0;">+<span id="LC837" class="line" lang="haskell"> <span class="c1" style="color: #998; font-style: italic;">-- leads to 10-20% regressions in the T9872x tests, so we don't do it.</span></span>
</pre>
</td>
</tr>
<tr class="line_holder" id="" style="line-height: 1.6;">
<td class="diff-line-num old_line" data-linenumber="835" style="width: 35px; color: rgba(0,0,0,0.3); border-right-width: 1px; border-right-color: #f0f0f0; border-right-style: solid; padding: 0 5px;" align="right" bgcolor="#fafafa">
835
</td>
<td class="diff-line-num new_line" data-linenumber="838" style="width: 35px; color: rgba(0,0,0,0.3); border-right-width: 1px; border-right-color: #f0f0f0; border-right-style: solid; padding: 0 5px;" align="right" bgcolor="#fafafa">
838
</td>
<td class="line_content" style="padding-left: 0.5em; padding-right: 0.5em;">
<pre style="margin: 0;"> <span id="LC838" class="line" lang="haskell"> <span class="kt" style="color: #458; font-weight: 600;">Nothing</span> <span class="o" style="font-weight: 600;">-></span> <span class="c1" style="color: #998; font-style: italic;">-- we have made no progress at all: STEP 7.</span></span>
</pre>
</td>
</tr>
<tr class="line_holder" id="" style="line-height: 1.6;">
<td class="diff-line-num old_line" data-linenumber="836" style="width: 35px; color: rgba(0,0,0,0.3); border-right-width: 1px; border-right-color: #f0f0f0; border-right-style: solid; padding: 0 5px;" align="right" bgcolor="#fafafa">
836
</td>
<td class="diff-line-num new_line" data-linenumber="839" style="width: 35px; color: rgba(0,0,0,0.3); border-right-width: 1px; border-right-color: #f0f0f0; border-right-style: solid; padding: 0 5px;" align="right" bgcolor="#fafafa">
839
</td>
<td class="line_content" style="padding-left: 0.5em; padding-right: 0.5em;">
<pre style="margin: 0;"> <span id="LC839" class="line" lang="haskell"> <span class="n" style="color: #333;">return</span> <span class="p">(</span><span class="n" style="color: #333;">homogenise</span> <span class="n" style="color: #333;">reduced</span> <span class="p">(</span><span class="n" style="color: #333;">mkTcReflCo</span> <span class="n" style="color: #333;">role</span> <span class="n" style="color: #333;">reduced</span><span class="p">))</span></span>
</pre>
</td>
</tr>
<tr class="line_holder" id="" style="line-height: 1.6;">
<td class="diff-line-num old_line" data-linenumber="837" style="width: 35px; color: rgba(0,0,0,0.3); border-right-width: 1px; border-right-color: #f0f0f0; border-right-style: solid; padding: 0 5px;" align="right" bgcolor="#fafafa">
837
</td>
<td class="diff-line-num new_line" data-linenumber="840" style="width: 35px; color: rgba(0,0,0,0.3); border-right-width: 1px; border-right-color: #f0f0f0; border-right-style: solid; padding: 0 5px;" align="right" bgcolor="#fafafa">
840
</td>
<td class="line_content" style="padding-left: 0.5em; padding-right: 0.5em;">
<pre style="margin: 0;"> <span id="LC840" class="line" lang="haskell"> <span class="kr" style="font-weight: 600;">where</span></span>
</pre>
</td>
</tr>
</table>
<br>
</li>
</div>
<div class="footer" style="margin-top: 10px;">
<p style="font-size: small; color: #666;">
—
<br>
<a href="https://gitlab.haskell.org/ghc/ghc/-/commit/2b7af3cd500bb587736ff455645fb4cd5ff986f3">View it on GitLab</a>.
<br>
You're receiving this email because of your account on gitlab.haskell.org.
If you'd like to receive fewer emails, you can
adjust your notification settings.
<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/2b7af3cd500bb587736ff455645fb4cd5ff986f3"}}</script>
</p>
</div>
</body>
</html>