[SelectionDAG] Selection of DBG_VALUE using a PHI node result (pt 2)

Summary:
This is a follow up to rL331182. A PHI node can be split up into
several MIR PHI nodes when being selected. When there is a
dbg.value intrinsic that uses the result of such a PHI node we
need to select several DBG_VALUE instructions, with fragment
expressions, in order to do a correct selection.

Reviewers: rnk, aprantl, vsk

Reviewed By: vsk

Subscribers: mattd, llvm-commits, JDevlieghere, aprantl, gbedwell, rnk

Tags: #debug-info

Differential Revision: https://reviews.llvm.org/D46329

llvm-svn: 331337

1 files changed, 5 insertions, 0 deletions

diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.h b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.h
index af094e4ab1c..7ed61c64bf5 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.h
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.h
@@ -1048,6 +1048,11 @@ struct RegsForValue {
   void AddInlineAsmOperands(unsigned Kind, bool HasMatching,
                             unsigned MatchingIdx, const SDLoc &dl,
                             SelectionDAG &DAG, std::vector<SDValue> &Ops) const;
+
+  /// Check if the total RegCount is greater than one.
+  bool occupiesMultipleRegs() const {
+    return std::accumulate(RegCount.begin(), RegCount.end(), 0) > 1;
+  }
 };
 
 } // end namespace llvm