<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 - performance regression caused by e6a7e3b5e3e779a3bfb617c8d9ed4302edab2cef"
   href="https://bugs.llvm.org/show_bug.cgi?id=45263">45263</a>
          </td>
        </tr>

        <tr>
          <th>Summary</th>
          <td>performance regression caused by e6a7e3b5e3e779a3bfb617c8d9ed4302edab2cef
          </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>All
          </td>
        </tr>

        <tr>
          <th>Status</th>
          <td>NEW
          </td>
        </tr>

        <tr>
          <th>Severity</th>
          <td>release blocker
          </td>
        </tr>

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

        <tr>
          <th>Component</th>
          <td>Backend: X86
          </td>
        </tr>

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

        <tr>
          <th>Reporter</th>
          <td>wmi@google.com
          </td>
        </tr>

        <tr>
          <th>CC</th>
          <td>craig.topper@gmail.com, llvm-bugs@lists.llvm.org, llvm-dev@redking.me.uk, spatel+llvm@rotateright.com
          </td>
        </tr></table>
      <p>
        <div>
        <pre>We found the commit below causing 10% performance regression in one of our
benchmark:

<a href="https://github.com/llvm/llvm-project/commit/e6a7e3b5e3e779a3bfb617c8d9ed4302edab2cef">https://github.com/llvm/llvm-project/commit/e6a7e3b5e3e779a3bfb617c8d9ed4302edab2cef</a>

I extracted a testcase 1.cc and attached it. 

clang.1 -O3 -fexperimental-new-pass-manager -std=gnu++17 -msse4.1 1.cc -S -o
1.s

clang.2 -O3 -fexperimental-new-pass-manager -std=gnu++17 -msse4.1 1.cc -S -o
2.s

clang.1 was built at the version just before
e6a7e3b5e3e779a3bfb617c8d9ed4302edab2cef. clang.2 was built at
e6a7e3b5e3e779a3bfb617c8d9ed4302edab2cef. Searching the loop "This Inner Loop
Header: Depth=2". 1.s has 65 instructions in the loop. 2.s has 72 instructions.</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>