<div dir="ltr">Testcase?</div><div class="gmail_extra"><br><div class="gmail_quote">On Thu, Feb 12, 2015 at 4:17 PM, Michael Zolotukhin <span dir="ltr"><<a href="mailto:mzolotukhin@apple.com" target="_blank">mzolotukhin@apple.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Author: mzolotukhin<br>
Date: Thu Feb 12 18:17:03 2015<br>
New Revision: 228988<br>
<br>
URL: <a href="http://llvm.org/viewvc/llvm-project?rev=228988&view=rev" target="_blank">http://llvm.org/viewvc/llvm-project?rev=228988&view=rev</a><br>
Log:<br>
Prevent division by 0.<br>
<br>
When we try to estimate number of potentially removed instructions in<br>
loop unroller, we analyze first N iterations and then scale the<br>
computed number by TripCount/N. We should bail out early if N is 0.<br>
<br>
Modified:<br>
    llvm/trunk/lib/Transforms/Scalar/LoopUnrollPass.cpp<br>
<br>
Modified: llvm/trunk/lib/Transforms/Scalar/LoopUnrollPass.cpp<br>
URL: <a href="http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/LoopUnrollPass.cpp?rev=228988&r1=228987&r2=228988&view=diff" target="_blank">http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/LoopUnrollPass.cpp?rev=228988&r1=228987&r2=228988&view=diff</a><br>
==============================================================================<br>
--- llvm/trunk/lib/Transforms/Scalar/LoopUnrollPass.cpp (original)<br>
+++ llvm/trunk/lib/Transforms/Scalar/LoopUnrollPass.cpp Thu Feb 12 18:17:03 2015<br>
@@ -548,7 +548,7 @@ static unsigned<br>
 approximateNumberOfOptimizedInstructions(const Loop *L, ScalarEvolution &SE,<br>
                                          unsigned TripCount,<br>
                                          const TargetTransformInfo &TTI) {<br>
-  if (!TripCount)<br>
+  if (!TripCount || !UnrollMaxIterationsCountToAnalyze)<br>
     return 0;<br>
<br>
   UnrollAnalyzer UA(L, TripCount, SE, TTI);<br>
<br>
<br>
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</blockquote></div><br></div>