<html><head><meta http-equiv="Content-Type" content="text/html charset=us-ascii"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class="">+Tanya for the account issue.<div class=""><br class=""></div><div class=""><div><blockquote type="cite" class=""><div class="">On Oct 27, 2016, at 11:36 AM, Eric Martin via llvm-dev <<a href="mailto:llvm-dev@lists.llvm.org" class="">llvm-dev@lists.llvm.org</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><div dir="ltr" class="">Hi,<div class="">I intended to file this bug on Bugzilla, but I've received no response from llvm-admin in the 10 days since asking for a Bugzilla account.</div><div class=""><br class=""></div><div class="">I've written 2 test functions in C that take in a float array x of size n and output float array f(x), where f is either fabsf or logf. The LLVM 3.9 auto-vectorization docs claim that both functions will be vectorized: <a href="http://llvm.org/releases/3.9.0/docs/Vectorizers.html#vectorization-of-function-calls" class="">http://llvm.org/releases/3.9.0/docs/Vectorizers.html#vectorization-of-function-calls</a></div><div class=""><br class=""></div><div class="">When running with "clang -O3 -march=x86-64 -mavx2 -ffast-math test.c -S -emit-llvm", the function calling fabsf is vectorized while the function calling logf is not. This is with clang 3.9, but I've also confirmed the bug exists back to at least clang 3.7. I've also observed that logf calls break vectorization of more complex loops, and I provide the comparison with fabsf as a reduced test case.</div><div class=""><br class=""></div><div class="">I've attached the C program, a sh script to invoke clang with correct arguments, and an example LLVM IR file I produced by running on my system.</div><div class=""><br class=""></div><div class="">If someone makes a Bugzilla account for me, I can refile this bug there.</div><div class=""><br class=""></div><div class="">Best,</div><div class="">Eric Martin</div><div class=""><br class=""></div></div>
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