Add a deterministic finite automaton based packetizer for VLIW architectures

llvm-svn: 145629

1 files changed, 54 insertions, 0 deletions

diff --git a/llvm/utils/TableGen/DFAPacketizerEmitter.h b/llvm/utils/TableGen/DFAPacketizerEmitter.h
new file mode 100644
index 00000000000..f180fc69b91
--- /dev/null
+++ b/llvm/utils/TableGen/DFAPacketizerEmitter.h
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+//===- DFAPacketizerEmitter.h - Packetization DFA for a VLIW machine-------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This class parses the Schedule.td file and produces an API that can be used
+// to reason about whether an instruction can be added to a packet on a VLIW
+// architecture. The class internally generates a deterministic finite
+// automaton (DFA) that models all possible mappings of machine instructions
+// to functional units as instructions are added to a packet.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/ADT/DenseSet.h"
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/CodeGen/Passes.h"
+#include "llvm/TableGen/TableGenBackend.h"
+#include <map>
+#include <string>
+
+namespace llvm {
+//
+// class DFAGen: class that generates and prints out the DFA for resource
+// tracking
+//
+class DFAGen : public TableGenBackend {
+private:
+  std::string TargetName;
+  //
+  // allInsnClasses is the set of all possible resources consumed by an
+  // InstrStage
+  //
+  DenseSet<unsigned> allInsnClasses;
+  RecordKeeper &Records;
+
+public:
+  DFAGen(RecordKeeper& R);
+
+  //
+  // collectAllInsnClasses: Populate allInsnClasses which is a set of units
+  // used in each stage.
+  //
+  void collectAllInsnClasses(const std::string &Name,
+                            Record *ItinData,
+                            unsigned &NStages,
+                            raw_ostream &OS);
+
+  void run(raw_ostream &OS);
+};
+}