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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D">Thanks Mehdi. I have confirmed that this instruction cannot pass with the verification and somehow it is generated by the CFGSimplify. That is a bug in that phase
of CFGSimplify.<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D">Thanks,<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D">Jin<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">From:</span></b><span style="font-size:11.0pt;font-family:"Calibri",sans-serif"> mehdi.amini@apple.com [mailto:mehdi.amini@apple.com]
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<b>Sent:</b> Friday, December 2, 2016 10:10 AM<br>
<b>To:</b> Lin, Jin <jin.lin@intel.com><br>
<b>Cc:</b> llvm-dev@lists.llvm.org<br>
<b>Subject:</b> Re: [llvm-dev] Is the instruction %4 = select i1 %tobool.i, metadata !12, metadata !10 legal?<o:p></o:p></span></p>
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<p class="MsoNormal">On Dec 2, 2016, at 10:06 AM, Lin, Jin via llvm-dev <<a href="mailto:llvm-dev@lists.llvm.org">llvm-dev@lists.llvm.org</a>> wrote:<o:p></o:p></p>
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<p class="MsoNormal" style="margin-bottom:12.0pt"><span style="font-size:9.0pt;font-family:"Verdana",sans-serif;color:#203864">Hi,</span><span style="font-size:11.0pt;font-family:"Calibri",sans-serif"><o:p></o:p></span></p>
<p class="MsoNormal" style="margin-bottom:12.0pt"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#203864">The phase of instruction combine cannot handle the instruction<span class="apple-converted-space"> </span></span><span style="font-size:9.0pt;font-family:"Verdana",sans-serif;color:#203864">%4
= select i1 %tobool.i, metadata !12, metadata !10 generated by the phase of CFG simplification and the compiler generates an assertion failure.</span><span style="font-size:11.0pt;font-family:"Calibri",sans-serif"><o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:9.0pt;font-family:"Verdana",sans-serif;color:#203864">I wonder whe</span><span style="font-size:10.0pt;font-family:"Verdana",sans-serif;color:#203864">ther this is valid LLVM IR:</span><span style="font-size:11.0pt;font-family:"Calibri",sans-serif"><o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Verdana",sans-serif;color:#203864"> </span><span style="font-size:11.0pt;font-family:"Calibri",sans-serif"><o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:9.0pt;font-family:"Verdana",sans-serif;color:#203864">%4 = select i1 %tobool.i, metadata !12, metadata !10</span><span style="font-size:11.0pt;font-family:"Calibri",sans-serif"><o:p></o:p></span></p>
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<p class="MsoNormal">No this does not seem valid to me.<o:p></o:p></p>
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<p class="MsoNormal">Is the verifier accepting it? (This is usually the easiest way to figure).<o:p></o:p></p>
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<p class="MsoNormal">—<o:p></o:p></p>
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<p class="MsoNormal">Mehdi<o:p></o:p></p>
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<p class="MsoNormal"><a name="_MailEndCompose"></a><span style="font-size:10.0pt;font-family:"Verdana",sans-serif;color:#203864"> </span><span style="font-size:11.0pt;font-family:"Calibri",sans-serif"><o:p></o:p></span></p>
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<p class="MsoNormal" style="margin-bottom:12.0pt"><span style="font-size:9.0pt;font-family:"Verdana",sans-serif;color:#203864"> </span><span style="font-size:11.0pt;font-family:"Calibri",sans-serif"><o:p></o:p></span></p>
<p class="MsoNormal" style="margin-bottom:12.0pt"><span style="font-size:9.0pt;font-family:"Verdana",sans-serif;color:#203864">Before CFGSimplify</span><span style="font-size:11.0pt;font-family:"Calibri",sans-serif"><o:p></o:p></span></p>
<p class="MsoNormal" style="margin-bottom:12.0pt"><span style="font-size:9.0pt;font-family:"Verdana",sans-serif;color:#203864">cond.true.i: ; preds = %entry<br>
%add.ptr.i = getelementptr inbounds i8, i8* %2, i64 8<br>
%left_.i.i = bitcast i8* %add.ptr.i to i32**<br>
%3 = call i32** @llvm.fakeload.p0p0i32(i32** %left_.i.i, metadata !8) #6 br label %_ZN1G7insert_Ev.exit<br>
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cond.false.i: ; preds = %entry<br>
%right_.i.i = getelementptr inbounds i8, i8* %2, i64 16<br>
%4 = bitcast i8* %right_.i.i to i32**<br>
%5 = call i32** @llvm.fakeload.p0p0i32(i32** %4, metadata !11) #6<br>
br label %_ZN1G7insert_Ev.exit<br>
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</span><span style="font-size:11.0pt;font-family:"Calibri",sans-serif"><o:p></o:p></span></p>
<p class="MsoNormal" style="margin-bottom:12.0pt"><span style="font-size:9.0pt;font-family:"Verdana",sans-serif;color:#203864">After CFGSimplify<br>
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</span><span style="font-size:9.0pt;font-family:"Verdana",sans-serif;color:red"> %4 = select i1 %tobool.i, metadata !12, metadata !10</span><span style="font-size:9.0pt;font-family:"Verdana",sans-serif;color:#203864"><br>
%add.ptr.i = getelementptr inbounds i8, i8* %2, i64 %3<br>
%left_.i.i = bitcast i8* %add.ptr.i to i32**<br>
%5 = call i32** @llvm.fakeload.p0p0i32(i32** %left_.i.i, metadata %4) #6<br>
%6 = load i32*, i32** %5, align 8, !tbaa !8</span><span style="font-size:11.0pt;font-family:"Calibri",sans-serif"><o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#203864">Thanks,</span><span style="font-size:11.0pt;font-family:"Calibri",sans-serif"><o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#203864"> </span><span style="font-size:11.0pt;font-family:"Calibri",sans-serif"><o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#203864">Jin</span><span style="font-size:11.0pt;font-family:"Calibri",sans-serif"><o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:9.0pt;font-family:"Helvetica",sans-serif">_______________________________________________<br>
LLVM Developers mailing list<br>
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</span><a href="http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev"><span style="font-size:9.0pt;font-family:"Helvetica",sans-serif;color:#954F72">http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev</span></a><o:p></o:p></p>
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