3 files changed, 60 insertions, 0 deletions

diff --git a/contrib/llvm/include/llvm/CodeGen/SelectionDAGISel.h b/contrib/llvm/include/llvm/CodeGen/SelectionDAGISel.h
index b5ec8cb..909364e 100644
--- a/contrib/llvm/include/llvm/CodeGen/SelectionDAGISel.h
+++ b/contrib/llvm/include/llvm/CodeGen/SelectionDAGISel.h
@@ -238,6 +238,12 @@ public:
                            const unsigned char *MatcherTable,
                            unsigned TableSize);
 
+  /// \brief Return true if complex patterns for this target can mutate the
+  /// DAG.
+  virtual bool ComplexPatternFuncMutatesDAG() const {
+    return false;
+  }
+
 private:
 
   // Calls to these functions are generated by tblgen.
diff --git a/contrib/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp b/contrib/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
index b8b4db4..392a0ef 100644
--- a/contrib/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
+++ b/contrib/llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
@@ -2345,6 +2345,45 @@ struct MatchScope {
   bool HasChainNodesMatched, HasGlueResultNodesMatched;
 };
 
+/// \\brief A DAG update listener to keep the matching state
+/// (i.e. RecordedNodes and MatchScope) uptodate if the target is allowed to
+/// change the DAG while matching.  X86 addressing mode matcher is an example
+/// for this.
+class MatchStateUpdater : public SelectionDAG::DAGUpdateListener
+{
+      SmallVectorImpl<std::pair<SDValue, SDNode*> > &RecordedNodes;
+      SmallVectorImpl<MatchScope> &MatchScopes;
+public:
+  MatchStateUpdater(SelectionDAG &DAG,
+                    SmallVectorImpl<std::pair<SDValue, SDNode*> > &RN,
+                    SmallVectorImpl<MatchScope> &MS) :
+    SelectionDAG::DAGUpdateListener(DAG),
+    RecordedNodes(RN), MatchScopes(MS) { }
+
+  void NodeDeleted(SDNode *N, SDNode *E) {
+    // Some early-returns here to avoid the search if we deleted the node or
+    // if the update comes from MorphNodeTo (MorphNodeTo is the last thing we
+    // do, so it's unnecessary to update matching state at that point).
+    // Neither of these can occur currently because we only install this
+    // update listener during matching a complex patterns.
+    if (!E || E->isMachineOpcode())
+      return;
+    // Performing linear search here does not matter because we almost never
+    // run this code.  You'd have to have a CSE during complex pattern
+    // matching.
+    for (SmallVectorImpl<std::pair<SDValue, SDNode*> >::iterator I =
+         RecordedNodes.begin(), IE = RecordedNodes.end(); I != IE; ++I)
+      if (I->first.getNode() == N)
+        I->first.setNode(E);
+
+    for (SmallVectorImpl<MatchScope>::iterator I = MatchScopes.begin(),
+         IE = MatchScopes.end(); I != IE; ++I)
+      for (SmallVector<SDValue, 4>::iterator J = I->NodeStack.begin(),
+           JE = I->NodeStack.end(); J != JE; ++J)
+        if (J->getNode() == N)
+          J->setNode(E);
+  }
+};
 }
 
 SDNode *SelectionDAGISel::
@@ -2599,6 +2638,14 @@ SelectCodeCommon(SDNode *NodeToMatch, const unsigned char *MatcherTable,
       unsigned CPNum = MatcherTable[MatcherIndex++];
       unsigned RecNo = MatcherTable[MatcherIndex++];
       assert(RecNo < RecordedNodes.size() && "Invalid CheckComplexPat");
+
+      // If target can modify DAG during matching, keep the matching state
+      // consistent.
+      OwningPtr<MatchStateUpdater> MSU;
+      if (ComplexPatternFuncMutatesDAG())
+        MSU.reset(new MatchStateUpdater(*CurDAG, RecordedNodes,
+                                        MatchScopes));
+
       if (!CheckComplexPattern(NodeToMatch, RecordedNodes[RecNo].second,
                                RecordedNodes[RecNo].first, CPNum,
                                RecordedNodes))
diff --git a/contrib/llvm/lib/Target/X86/X86ISelDAGToDAG.cpp b/contrib/llvm/lib/Target/X86/X86ISelDAGToDAG.cpp
index 36d1690..23b780f 100644
--- a/contrib/llvm/lib/Target/X86/X86ISelDAGToDAG.cpp
+++ b/contrib/llvm/lib/Target/X86/X86ISelDAGToDAG.cpp
@@ -290,6 +290,13 @@ namespace {
     const X86InstrInfo *getInstrInfo() const {
       return getTargetMachine().getInstrInfo();
     }
+
+    /// \brief Address-mode matching performs shift-of-and to and-of-shift
+    /// reassociation in order to expose more scaled addressing
+    /// opportunities.
+    bool ComplexPatternFuncMutatesDAG() const {
+      return true;
+    }
   };
 }