From: Eli Friedman <eli.friedman@gmail.com>
Date: Wed, 12 Oct 2011 22:46:45 +0000 (+0000)
Subject: Use a utility from MathExtras to clarify a check and avoid undefined behavior.  Based... 
X-Git-Url: http://plrg.eecs.uci.edu/git/?a=commitdiff_plain;h=5c75af6eb72bd74bc35f46e5037dd5646e04f3b6;p=oota-llvm.git

Use a utility from MathExtras to clarify a check and avoid undefined behavior.  Based on patch by Ahmed Charles.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@141829 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
index c3a0df3333c..d11bd94cb09 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -1679,7 +1679,7 @@ void SelectionDAGBuilder::visitBitTestHeader(BitTestBlock &B,
     UsePtrType = true;
   else {
     for (unsigned i = 0, e = B.Cases.size(); i != e; ++i)
-      if ((uint64_t)((int64_t)B.Cases[i].Mask >> VT.getSizeInBits()) + 1 >= 2) {
+      if (!isUIntN(VT.getSizeInBits(), B.Cases[i].Mask)) {
         // Switch table case range are encoded into series of masks.
         // Just use pointer type, it's guaranteed to fit.
         UsePtrType = true;