<html><head><meta http-equiv="Content-Type" content="text/html charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><div class="">There can also be other “problems" like this one: <a href="http://reviews.llvm.org/D6946" class="">http://reviews.llvm.org/D6946</a></div><div class=""><br class=""></div><div class="">- Matthias</div><br class=""><div><blockquote type="cite" class=""><div class="">On Apr 20, 2015, at 1:44 PM, Tim Northover <<a href="mailto:t.p.northover@gmail.com" class="">t.p.northover@gmail.com</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><blockquote type="cite" class="">The DAG combiner also performs the undefined shift -> undef though, so it<br class="">should still be OK<br class=""></blockquote><br class="">DAG combiner doesn't really run to convergence as far as I'm aware, so<br class="">you often get extremely difficult to test but necessary checks like<br class="">this.<br class=""><br class="">Tim.<br class="">_______________________________________________<br class="">LLVM Developers mailing list<br class=""><a href="mailto:LLVMdev@cs.uiuc.edu" class="">LLVMdev@cs.uiuc.edu</a> <a href="http://llvm.cs.uiuc.edu" class="">http://llvm.cs.uiuc.edu</a><br class=""><a href="http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev" class="">http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev</a><br class=""></div></blockquote></div><br class=""></body></html>