Initial support for an instruction selector emitter

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@7631 91177308-0d34-0410-b5e6-96231b3b80d8

utils/TableGen/InstrSelectorEmitter.cpp

@@ -0,0 +1,56 @@
+//===- InstrInfoEmitter.cpp - Generate a Instruction Set Desc. ------------===//
+//
+// This tablegen backend is responsible for emitting a description of the target
+// instruction set for the code generator.
+//
+//===----------------------------------------------------------------------===//
+
+#include "InstrSelectorEmitter.h"
+#include "Record.h"
+
+NodeType::ArgResultTypes NodeType::Translate(Record *R) {
+  const std::string &Name = R->getName();
+  if (Name == "DNRT_void") return Void;
+  if (Name == "DNRT_val" || Name == "DNAT_val") return Val;
+  if (Name == "DNRT_arg0" || Name == "DNAT_arg0") return Arg0;
+  if (Name == "DNAT_ptr") return Ptr;
+  throw "Unknown DagNodeResult Type '" + Name + "'!";
+}
+
+
+/// ProcessNodeTypes - Process all of the node types in the current
+/// RecordKeeper, turning them into the more accessible NodeTypes data
+/// structure.
+///
+void InstrSelectorEmitter::ProcessNodeTypes() {
+  std::vector<Record*> Nodes = Records.getAllDerivedDefinitions("DagNode");
+
+  for (unsigned i = 0, e = Nodes.size(); i != e; ++i) {
+    Record *Node = Nodes[i];
+    
+    // Translate the return type...
+    NodeType::ArgResultTypes RetTy =
+      NodeType::Translate(Node->getValueAsDef("RetType"));
+
+    // Translate the arguments...
+    ListInit *Args = Node->getValueAsListInit("ArgTypes");
+    std::vector<NodeType::ArgResultTypes> ArgTypes;
+
+    for (unsigned a = 0, e = Args->getSize(); a != e; ++a)
+      if (DefInit *DI = dynamic_cast<DefInit*>(Args->getElement(a)))
+        ArgTypes.push_back(NodeType::Translate(DI->getDef()));
+      else
+        throw "In node " + Node->getName() + ", argument is not a Def!";
+
+    // Add the node type mapping now...
+    NodeTypes[Node] = NodeType(RetTy, ArgTypes);
+  }  
+}
+
+void InstrSelectorEmitter::run(std::ostream &OS) {
+  // Type-check all of the node types to ensure we "understand" them.
+  ProcessNodeTypes();
+  
+  
+  
+}