Create a new class, MemOperand, for describing memory references

in the backend. Introduce a new SDNode type, MemOperandSDNode, for
holding a MemOperand in the SelectionDAG IR, and add a MemOperand
list to MachineInstr, and code to manage them. Remove the offset
field from SrcValueSDNode; uses of SrcValueSDNode that were using
it are all all using MemOperandSDNode now.

Also, begin updating some getLoad and getStore calls to use the
PseudoSourceValue objects.

Most of this was written by Florian Brander, some
reorganization and updating to TOT by me.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@46585 91177308-0d34-0410-b5e6-96231b3b80d8

utils/TableGen/DAGISelEmitter.cpp

@@ -311,6 +311,12 @@ private:
   std::vector<std::pair<std::string, std::string> > OrigChains;
   std::set<std::string> Duplicates;
 
+  /// LSI - Load/Store information.
+  /// Save loads/stores matched by a pattern, and generate a MemOperandSDNode
+  /// for each memory access. This facilitates the use of AliasAnalysis in
+  /// the backend.
+  std::vector<std::string> LSI;
+
   /// GeneratedCode - This is the buffer that we emit code to.  The first int
   /// indicates whether this is an exit predicate (something that should be
   /// tested, and if true, the match fails) [when 1], or normal code to emit
@@ -371,6 +377,15 @@ public:
   void EmitMatchCode(TreePatternNode *N, TreePatternNode *P,
                      const std::string &RootName, const std::string &ChainSuffix,
                      bool &FoundChain) {
+
+    // Save loads/stores matched by a pattern.
+    if (!N->isLeaf() && N->getName().empty() &&
+        ((N->getOperator()->getName() == "ld") ||
+          (N->getOperator()->getName() == "st") ||
+          (N->getOperator()->getName() == "ist"))) {
+      LSI.push_back(RootName);
+    }
+
     bool isRoot = (P == NULL);
     // Emit instruction predicates. Each predicate is just a string for now.
     if (isRoot) {
@@ -927,6 +942,18 @@ public:
         }
       }
 
+      // Generate MemOperandSDNodes nodes for each memory accesses covered by this
+      // pattern.
+      if (isRoot) {
+        std::vector<std::string>::const_iterator mi, mie;
+        for (mi = LSI.begin(), mie = LSI.end(); mi != mie; ++mi) {
+          emitCode("SDOperand LSI_" + *mi + " = "
+                   "CurDAG->getMemOperand(cast<LSBaseSDNode>(" +
+                   *mi + ")->getMemOperand());");
+          AllOps.push_back("LSI_" + *mi);
+        }
+      }
+
       // Emit all the chain and CopyToReg stuff.
       bool ChainEmitted = NodeHasChain;
       if (NodeHasChain)