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<p class="MsoNormal">Hi,<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">While trying to compile my program, I faced problem with Loop Vectorizer which is trying interleave a load instruction. Error mentioned below
<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Error message :: <i>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.<o:p></o:p></i></p>
<p class="MsoNormal">Source code :: <a href="https://github.com/llvm/llvm-project/blob/master/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp#L2375">
https://github.com/llvm/llvm-project/blob/master/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp#L2375</a><o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">I have reduced my program to a shorter test case(vect.ll is attached). The same problem is reproducible with opt.
<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Command to reproduce the error: <i>./opt -loop-vectorize -hexagon-autohvx=1 vect.ll -S<o:p></o:p></i></p>
<p class="MsoNormal"><i><o:p> </o:p></i></p>
<p class="MsoNormal">Based on my analysis, I see that <a href="https://github.com/llvm/llvm-project/blob/master/llvm/lib/Transforms/Vectorize/LoopVectorize.cpp#L2370">
Decision</a> is getting return value as CM_Interleave but Loop Vectorizer expects either of the following values:
<span style="font-size:9.0pt;font-family:Consolas;color:#24292E;background:white">
CM_Widen, CM_Widen_Reverse, CM_GatherScatter. </span>Otherwise it asserts out. <o:p>
</o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Could you please help in sharing insights on what could be an issue here ?<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Thanks,<o:p></o:p></p>
<p class="MsoNormal">Abhikrant<o:p></o:p></p>
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