<div dir="ltr">I'm leaning towards bug in clang's optimizer.  I've scanned this code multiple times and I really don't see any UB.  I ran it under ubsan on Linux and it did not report any problems.  <div><br></div><div>I guess maybe you could run it under ubsan on aarch64 as well?</div><div><br></div><div>Assuming that passes, where do we go from here?  I know 0 about the optimizer or how to fix a bug in it, especially one that only occurs in a backend I have no access to :-/</div></div><br><div class="gmail_quote"><div dir="ltr">On Tue, Oct 18, 2016 at 2:40 AM Renato Golin <<a href="mailto:renato.golin@linaro.org">renato.golin@linaro.org</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">On 18 October 2016 at 00:08, Zachary Turner via llvm-commits<br class="gmail_msg">
<<a href="mailto:llvm-commits@lists.llvm.org" class="gmail_msg" target="_blank">llvm-commits@lists.llvm.org</a>> wrote:<br class="gmail_msg">
> Author: zturner<br class="gmail_msg">
> Date: Mon Oct 17 18:08:47 2016<br class="gmail_msg">
> New Revision: 284437<br class="gmail_msg">
><br class="gmail_msg">
> URL: <a href="http://llvm.org/viewvc/llvm-project?rev=284437&view=rev" rel="noreferrer" class="gmail_msg" target="_blank">http://llvm.org/viewvc/llvm-project?rev=284437&view=rev</a><br class="gmail_msg">
> Log:<br class="gmail_msg">
> Rename HexStyle -> HexFormatStyle, and remove a constexpr.<br class="gmail_msg">
><br class="gmail_msg">
> This should fix the remaining broken builds.<br class="gmail_msg">
<br class="gmail_msg">
Hi Zach,<br class="gmail_msg">
<br class="gmail_msg">
Didn't quite fix all problems, but we're getting there... :)<br class="gmail_msg">
<br class="gmail_msg">
<a href="http://lab.llvm.org:8011/builders/clang-cmake-aarch64-full/builds/3344" rel="noreferrer" class="gmail_msg" target="_blank">http://lab.llvm.org:8011/builders/clang-cmake-aarch64-full/builds/3344</a><br class="gmail_msg">
<br class="gmail_msg">
[ RUN      ] NativeFormatTest.IntegerTests<br class="gmail_msg">
/home/buildslave/buildslave/clang-cmake-aarch64-full/llvm/unittests/Support/NativeFormatTests.cpp:249:<br class="gmail_msg">
Failure<br class="gmail_msg">
Value of: format_number(-10, IntegerStyle::Integer, 1)<br class="gmail_msg">
  Actual: "-0"<br class="gmail_msg">
Expected: "-10"<br class="gmail_msg">
[  FAILED  ] NativeFormatTest.IntegerTests (0 ms)<br class="gmail_msg">
<br class="gmail_msg">
I have reverted on r284462. Let me know if you need help testing.<br class="gmail_msg">
<br class="gmail_msg">
cheers,<br class="gmail_msg">
--renato<br class="gmail_msg">
</blockquote></div>