[Hexagon] Fix debug information for local objects

- Isolate the check for the existence of a stack frame into hasFP.
- Implement getFrameIndexReference for DWARF address computation.
- Use getFrameIndexReference for offset computation in eliminateFrameIndex.
- Preserve debug information for dynamically allocated stack objects.
- Prefer FP to access local objects at -O0.
- Add experimental code to skip allocframe when not strictly necessary
  (disabled by default).

llvm-svn: 250718

1 files changed, 4 insertions, 1 deletions

diff --git a/llvm/lib/Target/Hexagon/HexagonISelLowering.cpp b/llvm/lib/Target/Hexagon/HexagonISelLowering.cpp
index c6c44ab76da..4ebc596b34a 100644
--- a/llvm/lib/Target/Hexagon/HexagonISelLowering.cpp
+++ b/llvm/lib/Target/Hexagon/HexagonISelLowering.cpp
@@ -851,7 +851,10 @@ HexagonTargetLowering::LowerDYNAMIC_STACKALLOC(SDValue Op,
 
   SDValue AC = DAG.getConstant(A, dl, MVT::i32);
   SDVTList VTs = DAG.getVTList(MVT::i32, MVT::Other);
-  return DAG.getNode(HexagonISD::ALLOCA, dl, VTs, Chain, Size, AC);
+  SDValue AA = DAG.getNode(HexagonISD::ALLOCA, dl, VTs, Chain, Size, AC);
+  if (Op.getNode()->getHasDebugValue())
+    DAG.TransferDbgValues(Op, AA);
+  return AA;
 }
 
 SDValue