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      <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 --- - RA breaks invariance of generated code"
   href="https://llvm.org/bugs/show_bug.cgi?id=24500">24500</a>
          </td>
        </tr>

        <tr>
          <th>Summary</th>
          <td>RA breaks invariance of generated code
          </td>
        </tr>

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

        <tr>
          <th>Version</th>
          <td>trunk
          </td>
        </tr>

        <tr>
          <th>Hardware</th>
          <td>PC
          </td>
        </tr>

        <tr>
          <th>OS</th>
          <td>All
          </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>anton.nadolskiy@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=14746" name="attach_14746" title="Source and includes. Also two .s files that show difference">attachment 14746</a> <a href="attachment.cgi?id=14746&action=edit" title="Source and includes. Also two .s files that show difference">[details]</a></span>
Source and includes. Also two .s files that show difference

LLVM produces different code from run to run for given source. After examining
dump file I found that differences begin after Virtual Register Rewriter pass.
And it seems like problem appears only with -mregparm=3.

Example I took is from Spec2000 suite. It's 177.mesa/copypix.c  I couldn't
reduce test. I've tried to cut all but one function (where differences appear -
see .s files), but generated code seemed to be always the same.

Options I used: 
clang -Os -c -m32 -mregparm=3 -march=pentium -Wno-return-type -Xclang
-msoft-float -mstack-alignment=4 copypix.c

But as I said only -mregparm=3 matters.</pre>
        </div>
      </p>
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