<html>
<head>
<base href="https://bugs.llvm.org/">
</head>
<body><table border="1" cellspacing="0" cellpadding="8">
<tr>
<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - [NewPM] Inliner: Certain destructor calls are no longer inlined, preventing SROA, causing +10% runtime perf regression"
href="https://bugs.llvm.org/show_bug.cgi?id=50099">50099</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>[NewPM] Inliner: Certain destructor calls are no longer inlined, preventing SROA, causing +10% runtime perf regression
</td>
</tr>
<tr>
<th>Product</th>
<td>libraries
</td>
</tr>
<tr>
<th>Version</th>
<td>trunk
</td>
</tr>
<tr>
<th>Hardware</th>
<td>PC
</td>
</tr>
<tr>
<th>OS</th>
<td>Linux
</td>
</tr>
<tr>
<th>Status</th>
<td>NEW
</td>
</tr>
<tr>
<th>Severity</th>
<td>enhancement
</td>
</tr>
<tr>
<th>Priority</th>
<td>P
</td>
</tr>
<tr>
<th>Component</th>
<td>Interprocedural Analyses
</td>
</tr>
<tr>
<th>Assignee</th>
<td>unassignedbugs@nondot.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>lebedev.ri@gmail.com
</td>
</tr>
<tr>
<th>CC</th>
<td>llvm-bugs@lists.llvm.org
</td>
</tr></table>
<p>
<div>
<pre>Created <span class=""><a href="attachment.cgi?id=24799" name="attach_24799" title="unoptimized IR for reproduction">attachment 24799</a> <a href="attachment.cgi?id=24799&action=edit" title="unoptimized IR for reproduction">[details]</a></span>
unoptimized IR for reproduction
I'm seeing a rather big +10% runtime perf regression
from new-pm switch on a certain codepath.
I don't really have a small workable testcase yet,
but there's a full self-contained reproducer attached.
Here's how we can see that the problem is there:
$ clang -O3 -o old.ll -S -emit-llvm orig.ll -flegacy-pass-manager
$ clang -O3 -o new.ll -S -emit-llvm orig.ll
$ llvm-diff old.ll new.ll
<...>
function @_ZN8rawspeed6BufferD2Ev exists only in right module
<...>
in function _ZN8rawspeed23PanasonicDecompressorV511ProxyStream10parseBlockEv:
in block %entry:
> %FirstSection = alloca %"class.rawspeed::Buffer", align 8
> %SecondSection = alloca %"class.rawspeed::Buffer", align 8
> %0 = bitcast %"class.rawspeed::Buffer"* %FirstSection to i8*
> call void @llvm.lifetime.start.p0i8(i64 16, i8* nonnull %0) #17
> tail call void @llvm.experimental.noalias.scope.decl(metadata !135)
%pos.i = getelementptr inbounds
%"class.rawspeed::PanasonicDecompressorV5::ProxyStream",
%"class.rawspeed::PanasonicDecompressorV5::ProxyStream"* %this, i64 0, i32 0,
i32 1
%0 = load i32, i32* %pos.i, align 4, !tbaa !4, !noalias !9
> tail call void @llvm.experimental.noalias.scope.decl(metadata !138)
<...>
Inliner/inline cost model isn't something i'm familiar with,
so i'm posting this as is. Any suggestions how this can be approached from the
LLVM side?</pre>
</div>
</p>
<hr>
<span>You are receiving this mail because:</span>
<ul>
<li>You are on the CC list for the bug.</li>
</ul>
</body>
</html>