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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 --- - phi node arguments oscillate with passes loop-rotate and simplifycfg"
href="https://llvm.org/bugs/show_bug.cgi?id=27693">27693</a>
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<tr>
<th>Summary</th>
<td>phi node arguments oscillate with passes loop-rotate and simplifycfg
</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>
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<th>OS</th>
<td>Linux
</td>
</tr>
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<th>Status</th>
<td>NEW
</td>
</tr>
<tr>
<th>Severity</th>
<td>normal
</td>
</tr>
<tr>
<th>Priority</th>
<td>P
</td>
</tr>
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<th>Component</th>
<td>Scalar Optimizations
</td>
</tr>
<tr>
<th>Assignee</th>
<td>unassignedbugs@nondot.org
</td>
</tr>
<tr>
<th>Reporter</th>
<td>nwilson20@gmail.com
</td>
</tr>
<tr>
<th>CC</th>
<td>llvm-bugs@lists.llvm.org
</td>
</tr>
<tr>
<th>Classification</th>
<td>Unclassified
</td>
</tr></table>
<p>
<div>
<pre>Created <span class=""><a href="attachment.cgi?id=16342" name="attach_16342" title="loop-rotate_simplifycfg.ll">attachment 16342</a> <a href="attachment.cgi?id=16342&action=edit" title="loop-rotate_simplifycfg.ll">[details]</a></span>
loop-rotate_simplifycfg.ll
When using the flags -loop-rotate and -simplifycfg on the attached IR
(loop-rotate_simplifycfg.ll) the phi node arguments will keep flipping. This
was produced by using the attached IR and using the output as input back to
opt.
For example:
$ ./opt -S -loop-rotate -simplifycfg loop-rotate_simplifycfg.ll > out1.ll
$ ./opt -S -loop-rotate -simplifycfg out1.ll > out2.ll
$ ./opt -S -loop-rotate -simplifycfg out2.ll > out3.ll
$ diff out1.ll loop-rotate_simplifycfg.ll
1c1
< ; ModuleID = 'loop-rotate_simplifycfg.ll'
---
<span class="quote">> ; ModuleID = 'bugpoint-reduced-simplified.bc'</span >
23,24c23,24
< while.cond: ; preds = %cond.true.i57,
%entry, %while.cond
< %1 = phi %class.CBlockIndex.16.242.1142* [ null, %while.cond ], [ null,
%entry ], [ %0, %cond.true.i57 ]
---
<span class="quote">> while.cond: ; preds = %while.cond, %cond.true.i57, %entry
> %1 = phi %class.CBlockIndex.16.242.1142* [ %0, %cond.true.i57 ], [ null, %entry ], [ null, %while.cond ]</span >
$ diff out2.ll out1.ll
1c1
< ; ModuleID = 'out1.ll'
---
<span class="quote">> ; ModuleID = 'loop-rotate_simplifycfg.ll'</span >
24c24
< %1 = phi %class.CBlockIndex.16.242.1142* [ null, %while.cond ], [ %0,
%cond.true.i57 ], [ null, %entry ]
---
<span class="quote">> %1 = phi %class.CBlockIndex.16.242.1142* [ null, %while.cond ], [ null, %entry ], [ %0, %cond.true.i57 ]</span >
$ diff out3.ll out2.ll
1c1
< ; ModuleID = 'out2.ll'
---
<span class="quote">> ; ModuleID = 'out1.ll'</span >
24c24
< %1 = phi %class.CBlockIndex.16.242.1142* [ null, %while.cond ], [ null,
%entry ], [ %0, %cond.true.i57 ]
---
<span class="quote">> %1 = phi %class.CBlockIndex.16.242.1142* [ null, %while.cond ], [ %0, %cond.true.i57 ], [ null, %entry ]</span ></pre>
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