<html><head><meta http-equiv="Content-Type" content="text/html; charset=us-ascii"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class=""><br class=""><div><br class=""><blockquote type="cite" class=""><div class="">On Jun 14, 2021, at 17:55, Sanjay Patel via llvm-commits <<a href="mailto:llvm-commits@lists.llvm.org" class="">llvm-commits@lists.llvm.org</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><div class=""><br class="">Author: Sanjay Patel<br class="">Date: 2021-06-14T12:54:35-04:00<br class="">New Revision: 8591640379ac9175a8a8493126ecf0b44e3bb4af<br class=""><br class="">URL: <a href="https://github.com/llvm/llvm-project/commit/8591640379ac9175a8a8493126ecf0b44e3bb4af" class="">https://github.com/llvm/llvm-project/commit/8591640379ac9175a8a8493126ecf0b44e3bb4af</a><br class="">DIFF: <a href="https://github.com/llvm/llvm-project/commit/8591640379ac9175a8a8493126ecf0b44e3bb4af.diff" class="">https://github.com/llvm/llvm-project/commit/8591640379ac9175a8a8493126ecf0b44e3bb4af.diff</a><br class=""><br class="">LOG: [InstCombine] add DeMorgan folds for logical ops in select form<br class=""><br class="">We canonicalized to these select patterns (poison-safe logic)<br class="">with D101191, so we need to reduce 'not' ops when possible<br class="">as we would with 'and'/'or' instructions.<br class=""><br class="">This is shown in a secondary example in:<br class=""><a href="https://llvm.org/PR50389" class="">https://llvm.org/PR50389</a><br class=""><br class="">https://alive2.llvm.org/ce/z/BvsESh<br class=""><br class=""></div></div></blockquote><br class=""></div><div>It looks like this is causing an infinite loop in InstCombine: <font face="arial, sans-serif" class=""><span style="white-space: pre;" class=""><a href="https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=35399" class="">https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=35399</a></span></font></div><div><br class=""></div><div>Cheers,</div><div>Florian</div><br class=""></body></html>