From: Chris Lattner <sabre@nondot.org>
Date: Wed, 17 Feb 2010 06:23:39 +0000 (+0000)
Subject: Emulate the current isel's "IsChainCompatible" logic for now.
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=9a747f1305e76025df2323a03b805a284f2cde77;p=oota-llvm.git

Emulate the current isel's "IsChainCompatible" logic for now.
I'd like to eventually rip it out, but for now producing the
same selections as the old matcher is more important.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96458 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/include/llvm/CodeGen/DAGISelHeader.h b/include/llvm/CodeGen/DAGISelHeader.h
index 8cd11f6d267..70c2e02ff4f 100644
--- a/include/llvm/CodeGen/DAGISelHeader.h
+++ b/include/llvm/CodeGen/DAGISelHeader.h
@@ -217,7 +217,8 @@ enum BuiltinOpcodes {
   OPC_CheckComplexPat,
   OPC_CheckAndImm1, OPC_CheckAndImm2, OPC_CheckAndImm4, OPC_CheckAndImm8,
   OPC_CheckOrImm1, OPC_CheckOrImm2, OPC_CheckOrImm4, OPC_CheckOrImm8,
-  OPC_CheckFoldableChainNode
+  OPC_CheckFoldableChainNode,
+  OPC_CheckChainCompatible
 };
 
 struct MatchScope {
@@ -409,6 +410,13 @@ SDNode *SelectCodeCommon(SDNode *NodeToMatch, const unsigned char *MatcherTable,
       
       continue;
     }
+    case OPC_CheckChainCompatible: {
+      unsigned PrevNode = MatcherTable[MatcherIndex++];
+      assert(PrevNode < RecordedNodes.size() && "Invalid CheckChainCompatible");
+      if (!IsChainCompatible(RecordedNodes[PrevNode].getNode(), N.getNode()))
+        break;
+      continue;
+    }
     }
     
     // If the code reached this point, then the match failed pop out to the next
diff --git a/utils/TableGen/DAGISelMatcher.cpp b/utils/TableGen/DAGISelMatcher.cpp
index d7519cec292..83061093bc1 100644
--- a/utils/TableGen/DAGISelMatcher.cpp
+++ b/utils/TableGen/DAGISelMatcher.cpp
@@ -111,3 +111,9 @@ void CheckFoldableChainNodeMatcherNode::print(raw_ostream &OS,
   OS.indent(indent) << "CheckFoldableChainNode\n";
   printChild(OS, indent);
 }
+
+void CheckChainCompatibleMatcherNode::print(raw_ostream &OS,
+                                              unsigned indent) const {
+  OS.indent(indent) << "CheckChainCompatibleMatcherNode " << PreviousOp << "\n";
+  printChild(OS, indent);
+}
diff --git a/utils/TableGen/DAGISelMatcher.h b/utils/TableGen/DAGISelMatcher.h
index 53cf923e703..3aa29cdbe25 100644
--- a/utils/TableGen/DAGISelMatcher.h
+++ b/utils/TableGen/DAGISelMatcher.h
@@ -50,7 +50,8 @@ public:
     CheckComplexPat,
     CheckAndImm,
     CheckOrImm,
-    CheckFoldableChainNode
+    CheckFoldableChainNode,
+    CheckChainCompatible
   };
   const KindTy Kind;
   
@@ -380,6 +381,25 @@ public:
   virtual void print(raw_ostream &OS, unsigned indent = 0) const;
 };
 
+/// CheckChainCompatibleMatcherNode - Verify that the current node's chain
+/// operand is 'compatible' with the specified recorded node's.
+class CheckChainCompatibleMatcherNode : public MatcherNodeWithChild {
+  unsigned PreviousOp;
+public:
+  CheckChainCompatibleMatcherNode(unsigned previousop)
+    : MatcherNodeWithChild(CheckChainCompatible), PreviousOp(previousop) {}
+  
+  unsigned getPreviousOp() const { return PreviousOp; }
+  
+  static inline bool classof(const MatcherNode *N) {
+    return N->getKind() == CheckChainCompatible;
+  }
+  
+  virtual void print(raw_ostream &OS, unsigned indent = 0) const;
+};
+  
+  
+
 } // end namespace llvm
 
 #endif
diff --git a/utils/TableGen/DAGISelMatcherEmitter.cpp b/utils/TableGen/DAGISelMatcherEmitter.cpp
index 9b37254cbdd..8e29c471723 100644
--- a/utils/TableGen/DAGISelMatcherEmitter.cpp
+++ b/utils/TableGen/DAGISelMatcherEmitter.cpp
@@ -204,6 +204,10 @@ EmitMatcher(const MatcherNode *N, unsigned Indent) {
   case MatcherNode::CheckFoldableChainNode:
     OS << "OPC_CheckFoldableChainNode,\n";
     return 1;
+  case MatcherNode::CheckChainCompatible:
+    OS << "OPC_CheckChainCompatible, "
+       << cast<CheckChainCompatibleMatcherNode>(N)->getPreviousOp() << ",\n";
+    return 2;
   }
   assert(0 && "Unreachable");
   return 0;
diff --git a/utils/TableGen/DAGISelMatcherGen.cpp b/utils/TableGen/DAGISelMatcherGen.cpp
index e2ffb8e7171..8efcb4f982f 100644
--- a/utils/TableGen/DAGISelMatcherGen.cpp
+++ b/utils/TableGen/DAGISelMatcherGen.cpp
@@ -165,6 +165,16 @@ void MatcherGen::EmitLeafMatchCode(const TreePatternNode *N) {
       assert(NextRecordedOperandNo > 1 &&
              "Should have recorded input/result chains at least!");
       InputChains.push_back(NextRecordedOperandNo-1);
+
+      // IF we need to check chains, do so, see comment for
+      // "NodeHasProperty(SDNPHasChain" below.
+      if (InputChains.size() > 1) {
+        // FIXME: This is broken, we should eliminate this nonsense completely,
+        // but we want to produce the same selections that the old matcher does
+        // for now.
+        unsigned PrevOp = InputChains[InputChains.size()-2];
+        AddMatcherNode(new CheckChainCompatibleMatcherNode(PrevOp));
+      }
     }
     return;
   }
@@ -229,10 +239,13 @@ void MatcherGen::EmitOperatorMatchCode(const TreePatternNode *N,
     // sure that folding the chain won't induce cycles in the DAG.  This could
     // happen if there were an intermediate node between the indbr and load, for
     // example.
-    
-    // FIXME: Emit "IsChainCompatible(lastchain.getNode(), CurrentNode)".
-    // Rename IsChainCompatible -> IsChainUnreachable, add comment about
-    // complexity.
+    if (InputChains.size() > 1) {
+      // FIXME: This is broken, we should eliminate this nonsense completely,
+      // but we want to produce the same selections that the old matcher does
+      // for now.
+      unsigned PrevOp = InputChains[InputChains.size()-2];
+      AddMatcherNode(new CheckChainCompatibleMatcherNode(PrevOp));
+    }
     
     // Don't look at the input chain when matching the tree pattern to the
     // SDNode.