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<p class="MsoNormal">Hi,<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">I’ve noticed a clever trick in lib/CodeGen/SelectionDAG/DAGCombiner.cpp of identifying an AND whose only purpose is to reset the top bits as a potential zextload instead of extload in targets that support it. However, the code for identifying
the constant used in such an AND with a vector is wrong – it makes incorrect usage of the isConstantSplat() method, assuming it works differently from how it really does.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Attached is a patch that fixes this by using that method correctly, enabling a nice optimization on targets that support zextload. The fixed code is also much simpler and more efficient than the incorrect usage, becomes it removes an unneeded
loop.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Please review this patch and commit if acceptable,<o:p></o:p></p>
<p class="MsoListParagraph" style="text-indent:-18.0pt;mso-list:l0 level1 lfo2"><![if !supportLists]><span style="mso-list:Ignore">-<span style="font:7.0pt "Times New Roman"">
</span></span><![endif]><span dir="LTR"></span>Alon<o:p></o:p></p>
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