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<base href="https://llvm.org/bugs/" />
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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW --- - Infinite loop in SampleProfileLoader (inlineHotFunctions)"
href="https://llvm.org/bugs/show_bug.cgi?id=31119">31119</a>
</td>
</tr>
<tr>
<th>Summary</th>
<td>Infinite loop in SampleProfileLoader (inlineHotFunctions)
</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>Windows NT
</td>
</tr>
<tr>
<th>Status</th>
<td>NEW
</td>
</tr>
<tr>
<th>Severity</th>
<td>normal
</td>
</tr>
<tr>
<th>Priority</th>
<td>P
</td>
</tr>
<tr>
<th>Component</th>
<td>Interprocedural Optimizations
</td>
</tr>
<tr>
<th>Assignee</th>
<td>unassignedbugs@nondot.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>greg_bedwell@sn.scee.net
</td>
</tr>
<tr>
<th>CC</th>
<td>danielcdh@gmail.com, dnovillo@google.com, llvm-bugs@lists.llvm.org
</td>
</tr>
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<th>Classification</th>
<td>Unclassified
</td>
</tr></table>
<p>
<div>
<pre>We've had a report from a user out in the field of a hang in the compiler that
occurs when -fprofile-sample-use is used. I can see that it's getting stuck in
SampleProfileLoader::inlineHotFunctions due to never breaking out of the
while(true). I've reduced the (large) user-provided testcase and constructed
the following simple one that demonstrates the behaviour:
$ type pgo.txt
#
==============================================================================
_Z5alphav:102608:432
0.1: _Z4sort14GenericFunctor:105
#
==============================================================================
$ type test.cpp
//
=============================================================================
__attribute__((__nodebug__)) inline void _Sort(unsigned aa) {
if (aa)
_Sort(--aa);
}
struct GenericFunctor {
GenericFunctor() {}
};
unsigned depth;
__attribute__((__nodebug__)) inline void sort(GenericFunctor) { _Sort(depth); }
void alpha() { sort(GenericFunctor()); }
//
=============================================================================
$ clang -target x86_64-unknown-unknown -v
clang version 4.0.0 (<a href="http://llvm.org/git/clang.git">http://llvm.org/git/clang.git</a>
76fd46ed36e54c6418eb2d9254d9b99d1528311b) (<a href="http://llvm.org/git/llvm.git">http://llvm.org/git/llvm.git</a>
fcc1f76b4d065552630b28ec1d7959b692680c18)
Target: x86_64-unknown-unknown
Thread model: posix
InstalledDir:
C:\work\public-git\upstream-llvm\build-vs2015-ps4-master\Release\bin
$ clang -target x86_64-unknown-unknown -Rpass=sample -c test.cpp -O3 -g
$ clang -target x86_64-unknown-unknown -Rpass=sample -c test.cpp -O3 -g
-fprofile-sample-use=pgo.txt
test.cpp:11:16: remark: inlined hot callee '_Z4sort14GenericFunctor' with 105
samples into '_Z5alphav' [-Rpass=sample-profile]
void alpha() { sort(GenericFunctor()); }
^
test.cpp:11:16: remark: inlined hot callee '_Z5_Sortj' with 105 samples into
'_Z5alphav' [-Rpass=sample-profile]
test.cpp:11:16: remark: inlined hot callee '_Z5_Sortj' with 105 samples into
'_Z5alphav' [-Rpass=sample-profile]
test.cpp:11:16: remark: inlined hot callee '_Z5_Sortj' with 105 samples into
'_Z5alphav' [-Rpass=sample-profile]
test.cpp:11:16: remark: inlined hot callee '_Z5_Sortj' with 105 samples into
'_Z5alphav' [-Rpass=sample-profile]
test.cpp:11:16: remark: inlined hot callee '_Z5_Sortj' with 105 samples into
'_Z5alphav' [-Rpass=sample-profile]
test.cpp:11:16: remark: inlined hot callee '_Z5_Sortj' with 105 samples into
'_Z5alphav' [-Rpass=sample-profile]
test.cpp:11:16: remark: inlined hot callee '_Z5_Sortj' with 105 samples into
'_Z5alphav' [-Rpass=sample-profile]
^C
$</pre>
</div>
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