Make sure constant subscript is truncated to ptr size if it may not fit.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@64163 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/SelectionDAGBuild.cpp b/lib/CodeGen/SelectionDAG/SelectionDAGBuild.cpp
index 3c90cd7..7b613d7 100644
--- a/lib/CodeGen/SelectionDAG/SelectionDAGBuild.cpp
+++ b/lib/CodeGen/SelectionDAG/SelectionDAGBuild.cpp
@@ -2699,8 +2699,15 @@
         if (CI->getZExtValue() == 0) continue;
         uint64_t Offs =
             TD->getTypePaddedSize(Ty)*cast<ConstantInt>(CI)->getSExtValue();
+        SDValue OffsVal = DAG.getConstant(Offs, MVT::i64);
+        unsigned PtrBits = TLI.getPointerTy().getSizeInBits();
+        if (PtrBits < 64)
+          OffsVal = DAG.getNode(ISD::TRUNCATE, getCurDebugLoc(), 
+                                TLI.getPointerTy(), OffsVal);
+        else
+          OffsVal = DAG.getIntPtrConstant(Offs);
         N = DAG.getNode(ISD::ADD, getCurDebugLoc(), N.getValueType(), N,
-                        DAG.getIntPtrConstant(Offs));
+                        OffsVal);
         continue;
       }