<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 - Interleave failure in Loop Vectorizer"
   href="https://bugs.llvm.org/show_bug.cgi?id=45572">45572</a>
          </td>
        </tr>

        <tr>
          <th>Summary</th>
          <td>Interleave failure in Loop Vectorizer
          </td>
        </tr>

        <tr>
          <th>Product</th>
          <td>libraries
          </td>
        </tr>

        <tr>
          <th>Version</th>
          <td>10.0
          </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>enhancement
          </td>
        </tr>

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

        <tr>
          <th>Component</th>
          <td>Loop Optimizer
          </td>
        </tr>

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

        <tr>
          <th>Reporter</th>
          <td>quic_abhikran@quicinc.com
          </td>
        </tr>

        <tr>
          <th>CC</th>
          <td>llvm-bugs@lists.llvm.org
          </td>
        </tr></table>
      <p>
        <div>
        <pre>Created <span class=""><a href="attachment.cgi?id=23370" name="attach_23370" title="IR to reproduce the error">attachment 23370</a> <a href="attachment.cgi?id=23370&action=edit" title="IR to reproduce the error">[details]</a></span>
IR to reproduce the error

Hello,

I'm observing a problem with load instruction being vectorized(by Loop
Vectorizer) but erroring out because of the below mentioned error:

Error message :: void
llvm::InnerLoopVectorizer::vectorizeMemoryInstruction(llvm::Instruction*,
llvm::VPTransformState&, llvm::VPValue*, llvm::VPValue*, llvm::VPValue*):
Assertion `(Decision == LoopVectorizationCostModel::CM_Widen || Decision ==
LoopVectorizationCostModel::CM_Widen_Reverse || Decision ==
LoopVectorizationCostModel::CM_GatherScatter) && "CM decision is not to widen
the memory instruction"' failed.

Source code ::
<a href="https://github.com/llvm/llvm-project/blob/master/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp#L2373">https://github.com/llvm/llvm-project/blob/master/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp#L2373</a> 

The problem is observed because Decision variable is set to CM_Interleave.
While debugging, I found out that the decision is being set to CM_Interleave in
the following
line(<a href="https://github.com/llvm/llvm-project/blob/master/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp#L6088">https://github.com/llvm/llvm-project/blob/master/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp#L6088</a>
). But, CM_Interleave decision type is not supported in
InnerLoopVectorizer::vectorizeMemoryInstruction function. 

The attached file(vect.ll) is able to reproduce the error from LLVM master
branch.

Command to reproduce the error: 

     ./opt -loop-vectorize -hexagon-autohvx=1 vect.ll -S

Thanks,
Abhikrant</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>