<html xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<meta name="Title" content="">
<meta name="Keywords" content="">
<meta name="Generator" content="Microsoft Word 15 (filtered medium)">
<style><!--
/* Font Definitions */
@font-face
{font-family:"Cambria Math";
panose-1:2 4 5 3 5 4 6 3 2 4;}
@font-face
{font-family:Calibri;
panose-1:2 15 5 2 2 2 4 3 2 4;}
@font-face
{font-family:PMingLiU;
panose-1:2 2 5 0 0 0 0 0 0 0;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0in;
margin-bottom:.0001pt;
font-size:12.0pt;
font-family:"Times New Roman";}
a:link, span.MsoHyperlink
{mso-style-priority:99;
color:blue;
text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
{mso-style-priority:99;
color:purple;
text-decoration:underline;}
span.EmailStyle17
{mso-style-type:personal-reply;
font-family:Calibri;
color:windowtext;}
span.msoIns
{mso-style-type:export-only;
mso-style-name:"";
text-decoration:underline;
color:teal;}
.MsoChpDefault
{mso-style-type:export-only;
font-size:10.0pt;}
@page WordSection1
{size:8.5in 11.0in;
margin:1.0in 1.0in 1.0in 1.0in;}
div.WordSection1
{page:WordSection1;}
--></style>
</head>
<body bgcolor="white" lang="EN-US" link="blue" vlink="purple">
<div class="WordSection1">
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:Calibri">This change recovered the time lost processing @llvm.dbg intrinsics:<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:Calibri"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:Calibri">diff --git a/lib/Transforms/InstCombine/InstCombineInternal.h b/lib/Transforms/InstCombine/InstCombineInternal.h<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:Calibri">index 7100006..e70613c 100644<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:Calibri">--- a/lib/Transforms/InstCombine/InstCombineInternal.h<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:Calibri">+++ b/lib/Transforms/InstCombine/InstCombineInternal.h<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:Calibri">@@ -290,6 +290,7 @@ public:<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:Calibri"> Instruction *visitSelectInst(SelectInst &SI);<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:Calibri"> Instruction *visitCallInst(CallInst &CI);<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:Calibri"> Instruction *visitInvokeInst(InvokeInst &II);<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:Calibri">+ Instruction *visitDbgInfoIntrinsic(DbgInfoIntrinsic &CI) { return nullptr; }<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:Calibri"> <o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:Calibri"> Instruction *SliceUpIllegalIntegerPHI(PHINode &PN);<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:Calibri"> Instruction *visitPHINode(PHINode &PN);<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:Calibri"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:Calibri">The –O3 compile time speedup on my benchmark is ~3%. No llvm test failures.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:Calibri">Safe to commit?<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:Calibri"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:Calibri"><o:p> </o:p></span></p>
<div style="border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in">
<p class="MsoNormal" style="margin-left:.5in"><b><span style="font-family:Calibri;color:black">From:
</span></b><span style="font-family:Calibri;color:black">Craig Topper <craig.topper@gmail.com><br>
<b>Date: </b>Friday, April 14, 2017 at 2:31 PM<br>
<b>To: </b>Davide Italiano <davide@freebsd.org><br>
<b>Cc: </b>"Mikulin, Dmitry" <dmitry.mikulin@sony.com>, llvm-dev <llvm-dev@lists.llvm.org><br>
<b>Subject: </b>Re: [llvm-dev] Saving Compile Time in InstCombine<o:p></o:p></span></p>
</div>
<div>
<p class="MsoNormal" style="margin-left:.5in"><o:p> </o:p></p>
</div>
<div>
<p class="MsoNormal" style="margin-left:.5in">I think the easy way to ignore them is to add visitDbgDeclareInst and visitDbgValueInst to the InstCombine visitor tree and then just return nullptr from them.<o:p></o:p></p>
</div>
<div>
<p class="MsoNormal" style="margin-left:.5in"><br clear="all">
<o:p></o:p></p>
<div>
<div>
<p class="MsoNormal" style="margin-left:.5in">~Craig<o:p></o:p></p>
</div>
</div>
<p class="MsoNormal" style="margin-left:.5in"><o:p> </o:p></p>
<div>
<p class="MsoNormal" style="margin-left:.5in">On Fri, Apr 14, 2017 at 2:23 PM, Davide Italiano via llvm-dev <<a href="mailto:llvm-dev@lists.llvm.org" target="_blank">llvm-dev@lists.llvm.org</a>> wrote:<o:p></o:p></p>
<blockquote style="border:none;border-left:solid #CCCCCC 1.0pt;padding:0in 0in 0in 6.0pt;margin-left:4.8pt;margin-right:0in">
<p class="MsoNormal" style="margin-left:.5in">On Fri, Apr 14, 2017 at 2:19 PM, Mikulin, Dmitry<br>
<<a href="mailto:dmitry.mikulin@sony.com">dmitry.mikulin@sony.com</a>> wrote:<br>
><br>
>>> Is this a run with debug info? i.e. are you passing -g to the per-TU<br>
>>> pipeline? I'm inclined to think this is mostly an additive effect<br>
>>> adding matchers here and there that don't really hurt small testcases<br>
>>> but we pay the debt over time (in particular for LTO). Side note, I<br>
>>> noticed (and others did as well) that instcombine is way slower with<br>
>>> `-g` on (one of the reasons could be we walking much longer use lists,<br>
>>> due to the dbg use). Do you have numbers of instcombine ran on IR with<br>
>>> and without debug info?<br>
>><br>
>> I do have the numbers for the same app with and without debug info. The results above are for the no-debug version.<br>
>><br>
>> Total execution time of -O3 is 34% slower with debug info. The size of the debug IR is 162M vs 39M no-debug. Both profiles look relatively similar with the exception of bit code writer and verifier taking a larger share in the -g case.<br>
>><br>
>> Looking at InstCombine, it’s 23% slower. One notable thing is that CallInst takes significantly larger share with -g: 5s vs 13s, which translates to about half of the InstCombine slowdown. Need to understand why.<br>
><br>
> Ah, it’s all those calls to @llvm.dbg.* functions. I’ll explore if they can be safely ignored by InstCombine.<span style="font-family:PMingLiU"><br>
</span>><span style="font-family:PMingLiU"><br>
</span>><span style="font-family:PMingLiU"><br>
<br>
</span>I took a look and saw no immediate problems, also discussed with David<br>
Majnemer on IRC, who thinks we should just bail out early.<o:p></o:p></p>
<div>
<div>
<p class="MsoNormal" style="margin-left:.5in"><br>
--<br>
Davide<br>
<br>
"There are no solved problems; there are only problems that are more<br>
or less solved" -- Henri Poincare<br>
_______________________________________________<br>
LLVM Developers mailing list<br>
<a href="mailto:llvm-dev@lists.llvm.org">llvm-dev@lists.llvm.org</a><br>
<a href="http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev" target="_blank">http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev</a><o:p></o:p></p>
</div>
</div>
</blockquote>
</div>
<p class="MsoNormal" style="margin-left:.5in"><o:p> </o:p></p>
</div>
</div>
</body>
</html>