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<p class="MsoNormal">Hello Andy,<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Thank you for the comparison and the explanation of the effect. I’m still a beginner and I’m always happy to learn something new!<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">I understand now how the different values came to be and why they shouldn’t matter. Thank you all!<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Kind greetings<o:p></o:p></p>
<p class="MsoNormal">Björn<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal"><b>From:</b> Kaylor, Andrew <andrew.kaylor@intel.com> <br>
<b>Sent:</b> Dienstag, 5. Februar 2019 21:54<br>
<b>To:</b> Marcus Johnson <bumblebritches57@gmail.com><br>
<b>Cc:</b> Gaier, Bjoern <Bjoern.Gaier@horiba.com>; cfe-dev@lists.llvm.org<br>
<b>Subject:</b> RE: [cfe-dev] Clang-Cl - Representation of NAN; Code to reproduce<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Actually, it looks like MSVC always does the division. The sign bit doesn’t matter.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">FWIW, gcc also does the division in the non-volatile 0.0/0.0 case because it is preserving the floating point status flag that gets set by this operation. If you pass -ffast-math or -fno-trapping-math to gcc it will constant fold (to the
same value clang uses). I can’t get MSVC to do the constant folding, but I might just not know the right option.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">It's probably worth mentioning that clang doesn’t guarantee that floating point exception/status flag semantics will be preserved. That’s currently under development.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">-Andy<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><a name="_____replyseparator"></a><b>From:</b> Marcus Johnson <<a href="mailto:bumblebritches57@gmail.com">bumblebritches57@gmail.com</a>>
<br>
<b>Sent:</b> Tuesday, February 05, 2019 12:24 PM<br>
<b>To:</b> Kaylor, Andrew <<a href="mailto:andrew.kaylor@intel.com">andrew.kaylor@intel.com</a>><br>
<b>Cc:</b> Gaier, Bjoern <<a href="mailto:Bjoern.Gaier@horiba.com">Bjoern.Gaier@horiba.com</a>>;
<a href="mailto:cfe-dev@lists.llvm.org">cfe-dev@lists.llvm.org</a><br>
<b>Subject:</b> Re: [cfe-dev] Clang-Cl - Representation of NAN; Code to reproduce<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal"><span style="font-size:18.0pt">So MSVC's setting the sign bit when it shouldn't, report the bug to them.<o:p></o:p></span></p>
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