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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Courier New";color:#44546A">Hmmm, a quick look at the documentation for TargetTransformInfo doesn't look<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Courier New";color:#44546A">like it.
<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Courier New";color:#44546A"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Courier New";color:#44546A">In LegalizeDAG.cpp it uses TLI.getOperationAction() to find out if an SDNode<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Courier New";color:#44546A">should be expanded by the legalizer or passed down to the target. That's what<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Courier New";color:#44546A">I need to know, but I need it in a pass pre-legalization.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Courier New";color:#44546A"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Courier New";color:#44546A">This seems like weird layering, though. Having an "optimization" pass be<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Courier New";color:#44546A">looking into specific types of SDNode doesn't seem ideal. But I need to<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Courier New";color:#44546A">introduce branches, and I don't think I can do that in the SelectionDAG.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Courier New";color:#44546A">Branches in the middle of a basic block seems ... incorrect. Is there a<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Courier New";color:#44546A">good way to get ahold of the correct TargetLoweringBase from a pass? But<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Courier New";color:#44546A">there's still the layering issue, no?<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Courier New";color:#44546A"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Courier New";color:#44546A">Oh, and sorry for the top posting. This is the email client I'm stuck with.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Courier New";color:#44546A"><o:p> </o:p></span></p>
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<p class="MsoNormal"><b><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:windowtext">From:</span></b><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:windowtext"> Friedman, Eli [mailto:efriedma@codeaurora.org]
<br>
<b>Sent:</b> Tuesday, April 03, 2018 1:56 PM<br>
<b>To:</b> Kevin Neal <Kevin.Neal@sas.com>; llvm-dev@lists.llvm.org<br>
<b>Subject:</b> Re: [llvm-dev] [llvm] Query the target from an opt pass?<o:p></o:p></span></p>
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<p class="MsoNormal"><o:p> </o:p></p>
<p><b><i><span style="font-family:"Arial",sans-serif;color:red">EXTERNAL</span></i></b><span style="font-family:"Arial",sans-serif;color:red">
</span><o:p></o:p></p>
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<p class="MsoNormal">On 4/3/2018 9:25 AM, Kevin Neal via llvm-dev wrote:<o:p></o:p></p>
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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Courier New"">I'm working on the #pragma STDC FENV_ACCESS ON support, specifically<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Courier New"">the support for a strict version of the FP to unsigned int conversion.<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif"> </span><span style="font-size:11.0pt;font-family:"Courier New""><o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Courier New"">I've got a pass that runs and converts a new intrinsic into code that
<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Courier New"">uses the FP to signed int conversion code similar to how SelectionDAG<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Courier New"">handles this now. Except that SelectionDAG will let the target handle<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Courier New"">it if the target says it will.<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Courier New""> <o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Courier New"">How do I, from an "optimization" pass, query the target to see if it<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Courier New"">already has a better way of handling exactly this case? I grepped around<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Courier New"">and I didn't see anything in a pass that looked like what I need.<o:p></o:p></span></p>
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<p class="MsoNormal"><br>
TargetTransformInfo is probably what you're looking for.<br>
<br>
-Eli<br>
<br>
<o:p></o:p></p>
<pre>-- <o:p></o:p></pre>
<pre>Employee of Qualcomm Innovation Center, Inc.<o:p></o:p></pre>
<pre>Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project<o:p></o:p></pre>
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