<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40"><head><META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=us-ascii"><meta name=Generator content="Microsoft Word 15 (filtered medium)"><style><!--
/* Font Definitions */
@font-face
{font-family:"Cambria Math";
panose-1:2 4 5 3 5 4 6 3 2 4;}
@font-face
{font-family:Calibri;
panose-1:2 15 5 2 2 2 4 3 2 4;}
@font-face
{font-family:"Book Antiqua";
panose-1:2 4 6 2 5 3 5 3 3 4;}
@font-face
{font-family:Consolas;
panose-1:2 11 6 9 2 2 4 3 2 4;}
@font-face
{font-family:"Book Antiqua \,serif";
panose-1:0 0 0 0 0 0 0 0 0 0;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0cm;
margin-bottom:.0001pt;
font-size:11.0pt;
font-family:"Calibri",sans-serif;
color:black;
mso-fareast-language:EN-US;}
a:link, span.MsoHyperlink
{mso-style-priority:99;
color:#0563C1;
text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
{mso-style-priority:99;
color:#954F72;
text-decoration:underline;}
pre
{mso-style-priority:99;
mso-style-link:"HTML Preformatted Char";
margin:0cm;
margin-bottom:.0001pt;
font-size:10.0pt;
font-family:"Courier New";
color:black;}
span.EmailStyle17
{mso-style-type:personal;
font-family:"Book Antiqua",serif;
color:windowtext;
font-weight:normal;
font-style:normal;
text-decoration:none none;}
span.HTMLPreformattedChar
{mso-style-name:"HTML Preformatted Char";
mso-style-priority:99;
mso-style-link:"HTML Preformatted";
font-family:Consolas;
color:black;
mso-fareast-language:EN-US;}
span.EmailStyle20
{mso-style-type:personal-reply;
font-family:"Book Antiqua",serif;
color:#943634;
font-weight:normal;
font-style:normal;
text-decoration:none none;}
.MsoChpDefault
{mso-style-type:export-only;
font-size:10.0pt;}
@page WordSection1
{size:612.0pt 792.0pt;
margin:72.0pt 72.0pt 72.0pt 72.0pt;}
div.WordSection1
{page:WordSection1;}
--></style><!--[if gte mso 9]><xml>
<o:shapedefaults v:ext="edit" spidmax="1026" />
</xml><![endif]--><!--[if gte mso 9]><xml>
<o:shapelayout v:ext="edit">
<o:idmap v:ext="edit" data="1" />
</o:shapelayout></xml><![endif]--></head><body bgcolor=white lang=EN-IE link="#0563C1" vlink="#954F72"><div class=WordSection1><p class=MsoNormal><span style='font-size:12.0pt;font-family:"Book Antiqua",serif;color:#943634'>Thanks Eli,<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:12.0pt;font-family:"Book Antiqua",serif;color:#943634'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:12.0pt;font-family:"Book Antiqua",serif;color:#943634'>Hadn’t thought of that. Yes, it us present in the IR emitted from CLang, so I’ll have to see if I find where it changes by dumping the IR between passes.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:12.0pt;font-family:"Book Antiqua",serif;color:#943634'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:12.0pt;font-family:"Book Antiqua",serif;color:#943634'>All the best,<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:12.0pt;font-family:"Book Antiqua",serif;color:#943634'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:12.0pt;font-family:"Book Antiqua",serif;color:#943634'> Martin<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:12.0pt;font-family:"Book Antiqua",serif;color:#943634'><o:p> </o:p></span></p><div><div style='border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0cm 0cm 0cm'><p class=MsoNormal><b><span lang=EN-US style='color:windowtext;mso-fareast-language:EN-IE'>From:</span></b><span lang=EN-US style='color:windowtext;mso-fareast-language:EN-IE'> Friedman, Eli [mailto:efriedma@codeaurora.org] <br><b>Sent:</b> 25 September 2017 18:47<br><b>To:</b> Martin J. O'Riordan <martin.oriordan@movidius.com>; 'LLVM Developers' <llvm-dev@lists.llvm.org><br><b>Subject:</b> Re: [llvm-dev] '__builtin_nanl' and soft-FP64 support<o:p></o:p></span></p></div></div><p class=MsoNormal><o:p> </o:p></p><div><p class=MsoNormal>On 9/25/2017 5:35 AM, Martin J. O'Riordan via llvm-dev wrote:<span style='font-size:12.0pt;mso-fareast-language:EN-IE'><o:p></o:p></span></p></div><blockquote style='margin-top:5.0pt;margin-bottom:5.0pt'><p class=MsoNormal><span style='font-size:12.0pt;font-family:"Book Antiqua ,serif",serif'>I am seeing failures in two tests after migrating to v5.0 final, these are:</span><o:p></o:p></p><p class=MsoNormal style='margin-left:36.0pt'><span style='font-family:"Courier New"'>std/language.support/support.limits/limits/numeric.limits.members/quiet_NaN.pass.cpp</span><o:p></o:p></p><p class=MsoNormal><span style='font-size:12.0pt;font-family:"Book Antiqua ,serif",serif'>and:</span><o:p></o:p></p><p class=MsoNormal style='margin-left:36.0pt'><span style='font-family:"Courier New"'>std/language.support/support.limits/limits/numeric.limits.members/signaling_NaN.pass.cpp</span><o:p></o:p></p><p class=MsoNormal><span style='font-size:12.0pt;font-family:"Book Antiqua ,serif",serif'>However, these are new tests and it turns out that the underlying problem is that the builtin ‘</span><span style='font-size:12.0pt;font-family:"Courier New"'>__builtin_nanl(“”)</span><span style='font-size:12.0pt;font-family:"Book Antiqua ,serif",serif'>’ is returning the value </span><span style='font-size:12.0pt;font-family:"Courier New"'>0x0000000000000000</span><span style='font-size:12.0pt;font-family:"Book Antiqua ,serif",serif'>. I tested this builtin with our v4.0 compiler and it has the same problem, so this is not a regression but rather an existing bug exposed by the new LibC++ implementation of ‘</span><span style='font-size:12.0pt;font-family:"Courier New"'><limits></span><span style='font-size:12.0pt;font-family:"Book Antiqua ,serif",serif'>’.</span><o:p></o:p></p><p class=MsoNormal><span style='font-size:12.0pt;font-family:"Book Antiqua ,serif",serif'> </span><o:p></o:p></p><p class=MsoNormal><span style='font-size:12.0pt;font-family:"Book Antiqua ,serif",serif'>But our implementation of FP64 is a software only implementation using the FP64 support functions in ‘</span><span style='font-size:12.0pt;font-family:"Courier New"'>compiler-rt</span><span style='font-size:12.0pt;font-family:"Book Antiqua ,serif",serif'>’ and we have no lowering actions of our own.</span><o:p></o:p></p><p class=MsoNormal><span style='font-size:12.0pt;font-family:"Book Antiqua ,serif",serif'> </span><o:p></o:p></p><p class=MsoNormal><span style='font-size:12.0pt;font-family:"Book Antiqua ,serif",serif'>Where should I be looking to find out how to fix this? Is it a CLang issue of an LLVM issue?</span><o:p></o:p></p><p class=MsoNormal><span style='font-size:12.0pt;font-family:"Book Antiqua ,serif",serif'> </span><o:p></o:p></p></blockquote><p class=MsoNormal><span style='font-size:12.0pt;font-family:"Times New Roman",serif;mso-fareast-language:EN-IE'><br>__builtin_nanl("") gets constant-folded by clang; if you look at the LLVM IR, you should see something like "double 0x7FF8000000000000". Where exactly is 0x0000000000000000 showing up?<br><br>-Eli<br><br><o:p></o:p></span></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></div></body></html>