From c2d2c8939c276f7ae0cf4d1f8cc9dea7509f5033 Mon Sep 17 00:00:00 2001
From: Justin Holewinski <jholewinski@nvidia.com>
Date: Wed, 20 Mar 2013 14:51:01 +0000
Subject: [PATCH] Move SDNode order propagation to SDNodeOrdering, which also
 fixes a missed case of order propagation during isel.

Thanks Owen for the suggestion!

llvm-svn: 177525
---
 llvm/lib/CodeGen/SelectionDAG/LegalizeTypes.cpp    | 31 +++++++---------------
 llvm/lib/CodeGen/SelectionDAG/LegalizeTypes.h      |  1 -
 llvm/lib/CodeGen/SelectionDAG/SDNodeOrdering.h     |  4 ++-
 llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp |  2 ++
 4 files changed, 15 insertions(+), 23 deletions(-)

diff --git a/llvm/lib/CodeGen/SelectionDAG/LegalizeTypes.cpp b/llvm/lib/CodeGen/SelectionDAG/LegalizeTypes.cpp
index 1d6a981..b6436bf 100644
--- a/llvm/lib/CodeGen/SelectionDAG/LegalizeTypes.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/LegalizeTypes.cpp
@@ -619,17 +619,6 @@ void DAGTypeLegalizer::RemapValue(SDValue &N) {
   }
 }
 
-/// PropagateOrdering - Propagate SDNode ordering information from \p Old to
-/// \p New. Generally, this just means copying the ordering value, but if the
-/// new node is actually a recycled node with a lower ordering already, then
-/// we do not want to propagate the new (higher) ordering.
-void DAGTypeLegalizer::PropagateOrdering(SDNode *Old, SDNode *New) {
-  unsigned OldOrder = DAG.GetOrdering(Old);
-  unsigned NewOrder = DAG.GetOrdering(New);
-  if (NewOrder == 0 || (NewOrder > 0 && OldOrder < NewOrder))
-    DAG.AssignOrdering(New, OldOrder);
-}
-
 namespace {
   /// NodeUpdateListener - This class is a DAGUpdateListener that listens for
   /// updates to nodes and recomputes their ready state.
@@ -748,7 +737,7 @@ void DAGTypeLegalizer::SetPromotedInteger(SDValue Op, SDValue Result) {
   OpEntry = Result;
 
   // Propagate node ordering
-  PropagateOrdering(Op.getNode(), Result.getNode());
+  DAG.AssignOrdering(Result.getNode(), DAG.GetOrdering(Op.getNode()));
 }
 
 void DAGTypeLegalizer::SetSoftenedFloat(SDValue Op, SDValue Result) {
@@ -762,7 +751,7 @@ void DAGTypeLegalizer::SetSoftenedFloat(SDValue Op, SDValue Result) {
   OpEntry = Result;
 
   // Propagate node ordering
-  PropagateOrdering(Op.getNode(), Result.getNode());
+  DAG.AssignOrdering(Result.getNode(), DAG.GetOrdering(Op.getNode()));
 }
 
 void DAGTypeLegalizer::SetScalarizedVector(SDValue Op, SDValue Result) {
@@ -779,7 +768,7 @@ void DAGTypeLegalizer::SetScalarizedVector(SDValue Op, SDValue Result) {
   OpEntry = Result;
 
   // Propagate node ordering
-  PropagateOrdering(Op.getNode(), Result.getNode());
+  DAG.AssignOrdering(Result.getNode(), DAG.GetOrdering(Op.getNode()));
 }
 
 void DAGTypeLegalizer::GetExpandedInteger(SDValue Op, SDValue &Lo,
@@ -809,8 +798,8 @@ void DAGTypeLegalizer::SetExpandedInteger(SDValue Op, SDValue Lo,
   Entry.second = Hi;
 
   // Propagate ordering
-  PropagateOrdering(Op.getNode(), Lo.getNode());
-  PropagateOrdering(Op.getNode(), Hi.getNode());
+  DAG.AssignOrdering(Lo.getNode(), DAG.GetOrdering(Op.getNode()));
+  DAG.AssignOrdering(Hi.getNode(), DAG.GetOrdering(Op.getNode()));
 }
 
 void DAGTypeLegalizer::GetExpandedFloat(SDValue Op, SDValue &Lo,
@@ -840,8 +829,8 @@ void DAGTypeLegalizer::SetExpandedFloat(SDValue Op, SDValue Lo,
   Entry.second = Hi;
 
   // Propagate ordering
-  PropagateOrdering(Op.getNode(), Lo.getNode());
-  PropagateOrdering(Op.getNode(), Hi.getNode());
+  DAG.AssignOrdering(Lo.getNode(), DAG.GetOrdering(Op.getNode()));
+  DAG.AssignOrdering(Hi.getNode(), DAG.GetOrdering(Op.getNode()));
 }
 
 void DAGTypeLegalizer::GetSplitVector(SDValue Op, SDValue &Lo,
@@ -873,8 +862,8 @@ void DAGTypeLegalizer::SetSplitVector(SDValue Op, SDValue Lo,
   Entry.second = Hi;
 
   // Propagate ordering
-  PropagateOrdering(Op.getNode(), Lo.getNode());
-  PropagateOrdering(Op.getNode(), Hi.getNode());
+  DAG.AssignOrdering(Lo.getNode(), DAG.GetOrdering(Op.getNode()));
+  DAG.AssignOrdering(Hi.getNode(), DAG.GetOrdering(Op.getNode()));
 }
 
 void DAGTypeLegalizer::SetWidenedVector(SDValue Op, SDValue Result) {
@@ -888,7 +877,7 @@ void DAGTypeLegalizer::SetWidenedVector(SDValue Op, SDValue Result) {
   OpEntry = Result;
 
   // Propagate node ordering
-  PropagateOrdering(Op.getNode(), Result.getNode());
+  DAG.AssignOrdering(Result.getNode(), DAG.GetOrdering(Op.getNode()));
 }
 
 
diff --git a/llvm/lib/CodeGen/SelectionDAG/LegalizeTypes.h b/llvm/lib/CodeGen/SelectionDAG/LegalizeTypes.h
index b8b5ba8..27b3cf2 100644
--- a/llvm/lib/CodeGen/SelectionDAG/LegalizeTypes.h
+++ b/llvm/lib/CodeGen/SelectionDAG/LegalizeTypes.h
@@ -143,7 +143,6 @@ private:
   void ExpungeNode(SDNode *N);
   void PerformExpensiveChecks();
   void RemapValue(SDValue &N);
-  void PropagateOrdering(SDNode *Old, SDNode *New);
 
   // Common routines.
   SDValue BitConvertToInteger(SDValue Op);
diff --git a/llvm/lib/CodeGen/SelectionDAG/SDNodeOrdering.h b/llvm/lib/CodeGen/SelectionDAG/SDNodeOrdering.h
index d2269f8..74010a8 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SDNodeOrdering.h
+++ b/llvm/lib/CodeGen/SelectionDAG/SDNodeOrdering.h
@@ -34,7 +34,9 @@ public:
   SDNodeOrdering() {}
 
   void add(const SDNode *Node, unsigned O) {
-    OrderMap[Node] = O;
+    unsigned OldOrder = getOrder(Node);
+    if (OldOrder == 0 || (OldOrder > 0 && O < OldOrder))
+      OrderMap[Node] = O;
   }
   void remove(const SDNode *Node) {
     DenseMap<const SDNode*, unsigned>::iterator Itr = OrderMap.find(Node);
diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
index 15001f5..eeea9e4 100644
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
@@ -786,7 +786,9 @@ void SelectionDAGISel::DoInstructionSelection() {
         continue;
       // Replace node.
       if (ResNode) {
+        // Propagate ordering
         CurDAG->AssignOrdering(ResNode, CurDAG->GetOrdering(Node));
+
         ReplaceUses(Node, ResNode);
       }
 
-- 
2.7.4