Index: llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.h
===================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.h
+++ llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.h
@@ -1053,6 +1053,9 @@
   bool occupiesMultipleRegs() const {
     return std::accumulate(RegCount.begin(), RegCount.end(), 0) > 1;
   }
+
+  /// Return a list of registers and their sizes.
+  SmallVector<std::pair<unsigned, unsigned>, 4> getRegsAndSizes() const;
 };
 
 } // end namespace llvm
Index: llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
===================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ llvm/trunk/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -971,6 +971,20 @@
   }
 }
 
+SmallVector<std::pair<unsigned, unsigned>, 4>
+RegsForValue::getRegsAndSizes() const {
+  SmallVector<std::pair<unsigned, unsigned>, 4> OutVec;
+  unsigned I = 0;
+  for (auto CountAndVT : zip_first(RegCount, RegVTs)) {
+    unsigned RegCount = std::get<0>(CountAndVT);
+    MVT RegisterVT = std::get<1>(CountAndVT);
+    unsigned RegisterSize = RegisterVT.getSizeInBits();
+    for (unsigned E = I + RegCount; I != E; ++I)
+      OutVec.push_back(std::make_pair(Regs[I], RegisterSize));
+  }
+  return OutVec;
+}
+
 void SelectionDAGBuilder::init(GCFunctionInfo *gfi, AliasAnalysis *aa,
                                const TargetLibraryInfo *li) {
   AA = aa;
@@ -4908,26 +4922,18 @@
       const auto &TLI = DAG.getTargetLoweringInfo();
       RegsForValue RFV(V->getContext(), TLI, DAG.getDataLayout(), VMI->second,
                        V->getType(), isABIRegCopy(V));
-      unsigned NumRegs =
-          std::accumulate(RFV.RegCount.begin(), RFV.RegCount.end(), 0);
-      if (NumRegs > 1) {
-        unsigned I = 0;
+      if (RFV.occupiesMultipleRegs()) {
         unsigned Offset = 0;
-        auto RegisterVT = RFV.RegVTs.begin();
-        for (auto RegCount : RFV.RegCount) {
-          unsigned RegisterSize = (RegisterVT++)->getSizeInBits();
-          for (unsigned E = I + RegCount; I != E; ++I) {
-            // The vregs are guaranteed to be allocated in sequence.
-            Op = MachineOperand::CreateReg(VMI->second + I, false);
-            auto FragmentExpr = DIExpression::createFragmentExpression(
-                Expr, Offset, RegisterSize);
-            if (!FragmentExpr)
-              continue;
-            FuncInfo.ArgDbgValues.push_back(
-                BuildMI(MF, DL, TII->get(TargetOpcode::DBG_VALUE), IsDbgDeclare,
-                        Op->getReg(), Variable, *FragmentExpr));
-            Offset += RegisterSize;
-          }
+        for (auto RegAndSize : RFV.getRegsAndSizes()) {
+          Op = MachineOperand::CreateReg(RegAndSize.first, false);
+          auto FragmentExpr = DIExpression::createFragmentExpression(
+              Expr, Offset, RegAndSize.second);
+          if (!FragmentExpr)
+            continue;
+          FuncInfo.ArgDbgValues.push_back(
+              BuildMI(MF, DL, TII->get(TargetOpcode::DBG_VALUE), IsDbgDeclare,
+                      Op->getReg(), Variable, *FragmentExpr));
+          Offset += RegAndSize.second;
         }
         return true;
       }
@@ -5265,34 +5271,28 @@
         RegsForValue RFV(V->getContext(), TLI, DAG.getDataLayout(), Reg,
                          V->getType(), false);
         if (RFV.occupiesMultipleRegs()) {
-          unsigned I = 0;
           unsigned Offset = 0;
           unsigned BitsToDescribe = 0;
           if (auto VarSize = Variable->getSizeInBits())
             BitsToDescribe = *VarSize;
           if (auto Fragment = Expression->getFragmentInfo())
             BitsToDescribe = Fragment->SizeInBits;
-          for (auto CountAndVT : zip_first(RFV.RegCount, RFV.RegVTs)) {
-            unsigned RegCount = std::get<0>(CountAndVT);
-            MVT RegisterVT = std::get<1>(CountAndVT);
-            unsigned RegisterSize = RegisterVT.getSizeInBits();
-            for (unsigned E = I + RegCount; I != E; ++I) {
-              // Bail out if all bits already are described.
-              if (Offset >= BitsToDescribe)
-                break;
-              unsigned FragmentSize = (Offset + RegisterSize > BitsToDescribe)
-                  ? BitsToDescribe - Offset
-                  : RegisterSize;
-              auto FragmentExpr = DIExpression::createFragmentExpression(
-                  Expression, Offset, FragmentSize);
-              if (!FragmentExpr)
+          for (auto RegAndSize : RFV.getRegsAndSizes()) {
+            unsigned RegisterSize = RegAndSize.second;
+            // Bail out if all bits are described already.
+            if (Offset >= BitsToDescribe)
+              break;
+            unsigned FragmentSize = (Offset + RegisterSize > BitsToDescribe)
+                ? BitsToDescribe - Offset
+                : RegisterSize;
+            auto FragmentExpr = DIExpression::createFragmentExpression(
+                Expression, Offset, FragmentSize);
+            if (!FragmentExpr)
                 continue;
-              // The vregs are guaranteed to be allocated in sequence.
-              SDV = DAG.getVRegDbgValue(Variable, *FragmentExpr, Reg + I,
-                                        false, dl, SDNodeOrder);
-              DAG.AddDbgValue(SDV, nullptr, false);
-              Offset += RegisterSize;
-            }
+            SDV = DAG.getVRegDbgValue(Variable, *FragmentExpr, RegAndSize.first,
+                                      false, dl, SDNodeOrder);
+            DAG.AddDbgValue(SDV, nullptr, false);
+            Offset += RegisterSize;
           }
         } else {
           SDV = DAG.getVRegDbgValue(Variable, Expression, Reg, false, dl,