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<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US">Isn’t this a typcial situation when the is_stmt field in the DWARF line table should be used?<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US">If we set is_stmt=0 for the instruction loading the constant, then a debugger can choose not to stop on that instruction when doing
“step” on source level. That way we can keep the original source location for a ConstantSDNode, but also telling the debugger that this isn’t a recommended breakpoint location for that line. Using is_stmt=0 is ofcourse only interesting if the constant load
I hoisted so that it isn’t adjacent to other is_stmt=1 instructions on the same line.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif;mso-fareast-language:EN-US">/Björn<o:p></o:p></span></p>
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<p class="MsoNormal"><b><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif">From:</span></b><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif"> llvm-dev <llvm-dev-bounces@lists.llvm.org>
<b>On Behalf Of </b>via llvm-dev<br>
<b>Sent:</b> den 21 juni 2018 15:08<br>
<b>To:</b> mbraun@apple.com<br>
<b>Cc:</b> llvm-dev@lists.llvm.org; davidxl@google.com; jbogner@apple.com<br>
<b>Subject:</b> Re: [llvm-dev] [RFC] Removing debug locations from ConstantSDNodes<o:p></o:p></span></p>
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<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D"><a href="mailto:mbraun@apple.com">mbraun@apple.com</a> wrote:<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal" style="margin-left:36.0pt"><span lang="EN-US">FWIW: Debug information on constants feels odd to me. They are just values not something that is executed so conceptually I would not expect them to "happen" at a specific time/place in the
program. That said most numbers are copied into registers or stored into memory and that is of course an interesting action. So in the original example I would hope to see debug info on whatever instructions are used to fill the array with values.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D">+1. Constants are not inherently interesting, but loading one as an action preparatory to computing a value or setting up a parameter in a call,
the instruction ought to be associated with the relevant source statement.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D">--paulr<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D"><o:p> </o:p></span></p>
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