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<p class="MsoNormal"><span style="font-size:12.0pt">I don’t think there should be duplicates in either. Do you have a test case that shows duplicates?<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt">Simon<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:12.0pt"><o:p> </o:p></span></p>
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<p class="MsoNormal"><b><span lang="EN-US">From:</span></b><span lang="EN-US"> ghc-devs <ghc-devs-bounces@haskell.org>
<b>On Behalf Of </b>Csaba Hruska<br>
<b>Sent:</b> 04 November 2018 11:22<br>
<b>To:</b> ghc-devs@haskell.org<br>
<b>Subject:</b> Re: StgRhsClosure freevar and argument name duplicates<o:p></o:p></span></p>
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Is it possible that GHC generates STG with invalid binding semantics for certain cases that the Cmm codegen fix or ignore?<o:p></o:p></p>
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This could explain my observations.<o:p></o:p></p>
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I've checked the Stg linter source (StgLint.hs ; GHC 8.2.2 and github master) and it does not check StgRhsClosure free var and binder list at all.<o:p></o:p></p>
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And the scope checker function (addInScopeVars) does not check for duplicates.<o:p></o:p></p>
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<o:p> </o:p></p>
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Any thoughts?<o:p></o:p></p>
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<o:p> </o:p></p>
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Cheers,<o:p></o:p></p>
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Csaba<o:p></o:p></p>
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<o:p> </o:p></p>
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On Sat, Nov 3, 2018 at 9:53 AM Csaba Hruska <<a href="mailto:csaba.hruska@gmail.com">csaba.hruska@gmail.com</a>> wrote:<o:p></o:p></p>
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Hi,<o:p></o:p></p>
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<o:p> </o:p></p>
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Can StgRhsClosure's freevar list ([occ]) or argument list ([bndr]) contain duplicates?<o:p></o:p></p>
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<o:p> </o:p></p>
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Cheers,<o:p></o:p></p>
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Csaba<o:p></o:p></p>
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<o:p> </o:p></p>
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<span style="font-size:7.5pt;font-family:"Courier New"">data GenStgRhs bndr occ</span><br>
<span style="font-size:7.5pt;font-family:"Courier New""> = StgRhsClosure</span><br>
<span style="font-size:7.5pt;font-family:"Courier New""> CostCentreStack -- CCS to be attached (default is CurrentCCS)</span><br>
<span style="font-size:7.5pt;font-family:"Courier New""> StgBinderInfo -- Info about how this binder is used (see below)</span><br>
<span style="font-size:7.5pt;font-family:"Courier New""> <b>[occ]</b> -- non-global free vars; a list, rather than</span><br>
<span style="font-size:7.5pt;font-family:"Courier New""> -- a set, because order is important</span><br>
<span style="font-size:7.5pt;font-family:"Courier New""> !UpdateFlag -- ReEntrant | Updatable | SingleEntry</span><br>
<span style="font-size:7.5pt;font-family:"Courier New""> <b>[bndr]</b> -- arguments; if empty, then not a function;</span><br>
<span style="font-size:7.5pt;font-family:"Courier New""> -- as above, order is important.</span><br>
<span style="font-size:7.5pt;font-family:"Courier New""> (GenStgExpr bndr occ) -- body</span><o:p></o:p></p>
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<o:p> </o:p></p>
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