<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 - 800x compile time regression for AVR.cpp on sparcv9"
   href="https://bugs.llvm.org/show_bug.cgi?id=49473">49473</a>
          </td>
        </tr>

        <tr>
          <th>Summary</th>
          <td>800x compile time regression for AVR.cpp on sparcv9
          </td>
        </tr>

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

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

        <tr>
          <th>Hardware</th>
          <td>Sun
          </td>
        </tr>

        <tr>
          <th>OS</th>
          <td>Solaris
          </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>ro@gcc.gnu.org
          </td>
        </tr>

        <tr>
          <th>CC</th>
          <td>aeubanks@google.com, htmldeveloper@gmail.com, llvm-bugs@lists.llvm.org
          </td>
        </tr></table>
      <p>
        <div>
        <pre>Created <span class=""><a href="attachment.cgi?id=24601" name="attach_24601" title="-ftime report output">attachment 24601</a> <a href="attachment.cgi?id=24601&action=edit" title="-ftime report output">[details]</a></span>
-ftime report output

The compile time for clang/lib/Driver/ToolChains/AVR.cpp on Solaris/sparcv9 has
exploded recently: it grew from 4.92s to 1h 3m 50.16s, almost a factor of 800
and doubling the wall clock time of ninja -j96 on a Netra SPARC S7-2.

A reghunt identified the new PM as the culprit

commit 669ddd1e9b1226432b003dbba05b99f8e992285b
Author: Arthur Eubanks <<a href="mailto:aeubanks@google.com">aeubanks@google.com</a>>
Date:   Mon Jan 25 11:00:56 2021 -0800

    Turn on the new pass manager by default

and indeed compile time is back to normal with -flegacy-pass-manager.

Unfortunately, a build with -DENABLE_EXPERIMENTAL_NEW_PASS_MANAGER=OFF fails:

FAILED:
tools/clang/tools/extra/clangd/CMakeFiles/obj.clangDaemon.dir/ClangdLSPServer.cpp.o
[...]
Did not see access type in access path!
  store i64 %Handler.coerce1, i64* %.fca.1.gep, align 8, !tbaa !372
!372 = !{!370, !6, i64 8}

I'm attaching the -ftime-report output for reference.</pre>
        </div>
      </p>


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