Fix a crash when emitting debug info for multi-reg function arguments

by reusing more of the existing machinery

This is a follow-up to r312169.
Thanks to Björn Pettersson for the testcase!

llvm-svn: 312773

1 files changed, 18 insertions, 14 deletions

diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
index da0a9516fd1..fb32487ac42 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -4809,23 +4809,27 @@ bool SelectionDAGBuilder::EmitFuncArgumentDbgValue(
     // Check if ValueMap has reg number.
     DenseMap<const Value *, unsigned>::iterator VMI = FuncInfo.ValueMap.find(V);
     if (VMI != FuncInfo.ValueMap.end()) {
-      auto *Ty = V->getType();
       const auto &TLI = DAG.getTargetLoweringInfo();
-      EVT VT = TLI.getValueType(DAG.getDataLayout(), Ty);
-      unsigned NumRegs = TLI.getNumRegisters(Ty->getContext(), VT);
+      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) {
-        // The registers are guaranteed to be allocated in sequence.
+        unsigned I = 0;
         unsigned Offset = 0;
-        MVT RegisterVT = TLI.getRegisterType(Ty->getContext(), VT);
-        unsigned RegisterSize = RegisterVT.getSizeInBits();
-        for (unsigned I = 0; I != NumRegs; ++I) {
-          Op = MachineOperand::CreateReg(VMI->second + I, false);
-          auto *FragmentExpr = DIExpression::createFragmentExpression(
-              Expr, Offset, RegisterSize);
-          FuncInfo.ArgDbgValues.push_back(
-              BuildMI(MF, DL, TII->get(TargetOpcode::DBG_VALUE), IsDbgDeclare,
-                      Op->getReg(), Variable, FragmentExpr));
-          Offset += RegisterSize;
+        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);
+            FuncInfo.ArgDbgValues.push_back(
+                BuildMI(MF, DL, TII->get(TargetOpcode::DBG_VALUE), IsDbgDeclare,
+                        Op->getReg(), Variable, FragmentExpr));
+            Offset += RegisterSize;
+          }
         }
         return true;
       }