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    <head>
      <base href="https://llvm.org/bugs/" />
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    <body><table border="1" cellspacing="0" cellpadding="8">
        <tr>
          <th>Bug ID</th>
          <td><a class="bz_bug_link 
          bz_status_NEW "
   title="NEW --- - PowerPC DAG Pattern Instruction Selection Slowdown in LLVM 3.7"
   href="https://llvm.org/bugs/show_bug.cgi?id=25153">25153</a>
          </td>
        </tr>

        <tr>
          <th>Summary</th>
          <td>PowerPC DAG Pattern Instruction Selection Slowdown in LLVM 3.7
          </td>
        </tr>

        <tr>
          <th>Product</th>
          <td>new-bugs
          </td>
        </tr>

        <tr>
          <th>Version</th>
          <td>3.7
          </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>normal
          </td>
        </tr>

        <tr>
          <th>Priority</th>
          <td>P
          </td>
        </tr>

        <tr>
          <th>Component</th>
          <td>new bugs
          </td>
        </tr>

        <tr>
          <th>Assignee</th>
          <td>unassignedbugs@nondot.org
          </td>
        </tr>

        <tr>
          <th>Reporter</th>
          <td>matt.davis@pgroup.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=15059" name="attach_15059" title="Optimized llvm ir test">attachment 15059</a> <a href="attachment.cgi?id=15059&action=edit" title="Optimized llvm ir test">[details]</a></span>
Optimized llvm ir test

I have noted a considerable slowdown from llvm 3.5 regarding llc processing
optimized files.  Compiling the attached .llvm file went from ~15 seconds to ~3
minutes.

LLVM 3.7
--------
Compile: llvm/3.7/bin/llc test.ll -mcpu=native -O2 -o test.s -time-passes
Total:   3 Minutes with 190.9secs User Time in PowerPC DAG->DAG Pattern
Instruction Selection


Compile: llvm/3.7/bin/llc test_opt.llvm -mcpu=native -O2 -o test.s -time-passes
Total:   6 Seconds with 5.4secs User Time in PowerPC DAG->DAG Pattern
Instruction Selection 


LLVM 3.5
--------
Compile: llvm/3.5/bin/llc test.ll -mcpu=native -O2 -o test.s -time-passes
Total:   15 Seconds with 14.5secs User Time in PowerPC DAG->DAG Pattern
Instruction Selection

Compile: llvm/3.5/bin/llc test_opt.llvm -mcpu=native -O2 -o test.s -time-passes
Total:   1.3 Seconds with 1.01secs User Time in PowerPC DAG->DAG Pattern
Instruction Selection</pre>
        </div>
      </p>
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