[SelectionDAG] Add getNode debug messages

This adds debug messages to various functions that create new SDValue nodes.
This is e.g. useful to have during legalization, as otherwise it can prints
legalization info of nodes that did not appear in the dumps before.

Differential Revision: https://reviews.llvm.org/D36984

llvm-svn: 311444

1 files changed, 37 insertions, 8 deletions

diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
index 6489ca57b33..d555315c523 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp
@@ -87,6 +87,15 @@ static SDVTList makeVTList(const EVT *VTs, unsigned NumVTs) {
 void SelectionDAG::DAGUpdateListener::NodeDeleted(SDNode*, SDNode*) {}
 void SelectionDAG::DAGUpdateListener::NodeUpdated(SDNode*) {}
 
+#define DEBUG_TYPE "selectiondag"
+
+static void NewSDValueDbgMsg(SDValue V, StringRef Msg) {
+  DEBUG(
+    dbgs() << Msg;
+    V.dump();
+  );
+}
+
 //===----------------------------------------------------------------------===//
 //                              ConstantFPSDNode Class
 //===----------------------------------------------------------------------===//
@@ -1158,7 +1167,10 @@ SDValue SelectionDAG::getConstant(const ConstantInt &Val, const SDLoc &DL,
     SmallVector<SDValue, 8> Ops;
     for (unsigned i = 0, e = VT.getVectorNumElements(); i != e; ++i)
       Ops.insert(Ops.end(), EltParts.begin(), EltParts.end());
-    return getNode(ISD::BITCAST, DL, VT, getBuildVector(ViaVecVT, DL, Ops));
+
+    SDValue V = getNode(ISD::BITCAST, DL, VT, getBuildVector(ViaVecVT, DL, Ops));
+    NewSDValueDbgMsg(V, "Creating constant: ");
+    return V;
   }
 
   assert(Elt->getBitWidth() == EltVT.getSizeInBits() &&
@@ -1183,6 +1195,8 @@ SDValue SelectionDAG::getConstant(const ConstantInt &Val, const SDLoc &DL,
   SDValue Result(N, 0);
   if (VT.isVector())
     Result = getSplatBuildVector(VT, DL, Result);
+
+  NewSDValueDbgMsg(Result, "Creating constant: ");
   return Result;
 }
 
@@ -1224,6 +1238,7 @@ SDValue SelectionDAG::getConstantFP(const ConstantFP &V, const SDLoc &DL,
   SDValue Result(N, 0);
   if (VT.isVector())
     Result = getSplatBuildVector(VT, DL, Result);
+  NewSDValueDbgMsg(Result, "Creating fp constant: ");
   return Result;
 }
 
@@ -3456,7 +3471,9 @@ static SDValue FoldCONCAT_VECTORS(const SDLoc &DL, EVT VT,
                ? DAG.getZExtOrTrunc(Op, DL, SVT)
                : DAG.getSExtOrTrunc(Op, DL, SVT);
 
-  return DAG.getBuildVector(VT, DL, Elts);
+  SDValue V = DAG.getBuildVector(VT, DL, Elts);
+  NewSDValueDbgMsg(V, "New node fold concat vectors: ");
+  return V;
 }
 
 /// Gets or creates the specified node.
@@ -3472,7 +3489,9 @@ SDValue SelectionDAG::getNode(unsigned Opcode, const SDLoc &DL, EVT VT) {
   CSEMap.InsertNode(N, IP);
 
   InsertNode(N);
-  return SDValue(N, 0);
+  SDValue V = SDValue(N, 0);
+  NewSDValueDbgMsg(V, "Creating new node: ");
+  return V;
 }
 
 SDValue SelectionDAG::getNode(unsigned Opcode, const SDLoc &DL, EVT VT,
@@ -3833,7 +3852,9 @@ SDValue SelectionDAG::getNode(unsigned Opcode, const SDLoc &DL, EVT VT,
   }
 
   InsertNode(N);
-  return SDValue(N, 0);
+  SDValue V = SDValue(N, 0);
+  NewSDValueDbgMsg(V, "Creating new node: ");
+  return V;
 }
 
 static std::pair<APInt, bool> FoldValue(unsigned Opcode, const APInt &C1,
@@ -4106,7 +4127,9 @@ SDValue SelectionDAG::FoldConstantVectorArithmetic(unsigned Opcode,
     ScalarResults.push_back(ScalarResult);
   }
 
-  return getBuildVector(VT, DL, ScalarResults);
+  SDValue V = getBuildVector(VT, DL, ScalarResults);
+  NewSDValueDbgMsg(V, "New node fold constant vector: ");
+  return V;
 }
 
 SDValue SelectionDAG::getNode(unsigned Opcode, const SDLoc &DL, EVT VT,
@@ -4606,7 +4629,9 @@ SDValue SelectionDAG::getNode(unsigned Opcode, const SDLoc &DL, EVT VT,
   }
 
   InsertNode(N);
-  return SDValue(N, 0);
+  SDValue V = SDValue(N, 0);
+  NewSDValueDbgMsg(V, "Creating new node: ");
+  return V;
 }
 
 SDValue SelectionDAG::getNode(unsigned Opcode, const SDLoc &DL, EVT VT,
@@ -4641,8 +4666,10 @@ SDValue SelectionDAG::getNode(unsigned Opcode, const SDLoc &DL, EVT VT,
       return V;
     // Vector constant folding.
     SDValue Ops[] = {N1, N2, N3};
-    if (SDValue V = FoldConstantVectorArithmetic(Opcode, DL, VT, Ops))
+    if (SDValue V = FoldConstantVectorArithmetic(Opcode, DL, VT, Ops)) {
+      NewSDValueDbgMsg(V, "New node vector constant folding: ");
       return V;
+    }
     break;
   }
   case ISD::SELECT:
@@ -4714,7 +4741,9 @@ SDValue SelectionDAG::getNode(unsigned Opcode, const SDLoc &DL, EVT VT,
   }
 
   InsertNode(N);
-  return SDValue(N, 0);
+  SDValue V = SDValue(N, 0);
+  NewSDValueDbgMsg(V, "Creating new node: ");
+  return V;
 }
 
 SDValue SelectionDAG::getNode(unsigned Opcode, const SDLoc &DL, EVT VT,