From 979009ea616dd723b8c695ce85e735b8e1e6c66b Mon Sep 17 00:00:00 2001
From: Eli Friedman <eli.friedman@gmail.com>
Date: Wed, 12 Oct 2011 22:46:45 +0000
Subject: [PATCH] Use a utility from MathExtras to clarify a check and avoid
 undefined behavior.  Based on patch by Ahmed Charles.

llvm-svn: 141829
---
 llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
index c3a0df3333c5..d11bd94cb091 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/llvm/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;