<div dir="ltr">On 8 February 2013 12:28, Sebastien DELDON-GNB <span dir="ltr"><<a href="mailto:sebastien.deldon@st.com" target="_blank">sebastien.deldon@st.com</a>></span> wrote:<br><div class="gmail_extra"><div class="gmail_quote">
<blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex"><div lang="EN-US" link="blue" vlink="purple"><p class=""><span style="color:rgb(31,73,125);font-family:Calibri,sans-serif;font-size:11pt">Why for cortex-a9 vmlx-forwarding is enabled by default ? Is it to guarantee correctness or for performance purpose ? I’ve made some experiments and DISABLING vmlx-forwarding for cortex-a9 leads to generation of more vmla/vmls .f32 and significantly improve some benchmarks. I’ve not enter into a case where it significantly degrades performance or give incorrect answers.</span><br>
</p></div></blockquote><div style>I believe this is what you're looking for:</div><div><br></div><div><a href="http://article.gmane.org/gmane.comp.compilers.llvm.cvs/90709">http://article.gmane.org/gmane.comp.compilers.llvm.cvs/90709</a><br>
</div><div><br></div><div style>Performance only, but if you're seeing regressions, I'm interested to know what benchmarks and how much are they regressing/improving.</div><div><br></div><div> </div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex">
<div lang="EN-US" link="blue" vlink="purple"><div><p class=""><span style="font-size:11pt;font-family:Calibri,sans-serif;color:rgb(31,73,125)"><u></u><u></u></span></p><p class=""><span style="font-size:11pt;font-family:Calibri,sans-serif;color:rgb(31,73,125)">Thus my goal is to use my front-end to generate llvm neon intrinsics that maps to LLVM vmla/vmls f32 when I think it is appropriate and not to rely on disabling/enabling vmlx-forwarding.</span></p>
</div></div></blockquote><div style>In that case, you must disable the pass when you call the back-end.</div><div style><br></div><div style>cheers,</div><div style>--renato</div></div></div></div>