I'm introducing a new machine model to simultaneously allow simple

subtarget CPU descriptions and support new features of
MachineScheduler.

MachineModel has three categories of data:
1) Basic properties for coarse grained instruction cost model.
2) Scheduler Read/Write resources for simple per-opcode and operand cost model (TBD).
3) Instruction itineraties for detailed per-cycle reservation tables.

These will all live side-by-side. Any subtarget can use any
combination of them. Instruction itineraries will not change in the
near term. In the long run, I expect them to only be relevant for
in-order VLIW machines that have complex contraints and require a
precise scheduling/bundling model. Once itineraries are only actively
used by VLIW-ish targets, they could be replaced by something more
appropriate for those targets.

This tablegen backend rewrite sets things up for introducing
MachineModel type #2: per opcode/operand cost model.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159891 91177308-0d34-0410-b5e6-96231b3b80d8

7 files changed, 508 insertions, 229 deletions

diff --git a/utils/TableGen/CMakeLists.txt b/utils/TableGen/CMakeLists.txt
index c5585f5..0e14cba 100644
--- a/utils/TableGen/CMakeLists.txt
+++ b/utils/TableGen/CMakeLists.txt
@@ -11,6 +11,7 @@ add_tablegen(llvm-tblgen LLVM
   CodeGenDAGPatterns.cpp
   CodeGenInstruction.cpp
   CodeGenRegisters.cpp
+  CodeGenSchedule.cpp
   CodeGenTarget.cpp
   DAGISelEmitter.cpp
   DAGISelMatcherEmitter.cpp
diff --git a/utils/TableGen/CodeGenSchedule.cpp b/utils/TableGen/CodeGenSchedule.cpp
new file mode 100644
index 0000000..f57fd18
--- /dev/null
+++ b/utils/TableGen/CodeGenSchedule.cpp
@@ -0,0 +1,151 @@
+//===- CodeGenSchedule.cpp - Scheduling MachineModels ---------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines structures to encapsulate the machine model as decribed in
+// the target description.
+//
+//===----------------------------------------------------------------------===//
+
+#define DEBUG_TYPE "subtarget-emitter"
+
+#include "CodeGenSchedule.h"
+#include "CodeGenTarget.h"
+#include "llvm/Support/Debug.h"
+
+using namespace llvm;
+
+// CodeGenModels ctor interprets machine model records and populates maps.
+CodeGenSchedModels::CodeGenSchedModels(RecordKeeper &RK,
+                                       const CodeGenTarget &TGT):
+  Records(RK), Target(TGT), NumItineraryClasses(0), HasProcItineraries(false) {
+
+  // Populate SchedClassIdxMap and set NumItineraryClasses.
+  CollectSchedClasses();
+
+  // Populate ProcModelMap.
+  CollectProcModels();
+}
+
+// Visit all the instruction definitions for this target to gather and enumerate
+// the itinerary classes. These are the explicitly specified SchedClasses. More
+// SchedClasses may be inferred.
+void CodeGenSchedModels::CollectSchedClasses() {
+
+  // NoItinerary is always the first class at Index=0
+  SchedClasses.resize(1);
+  SchedClasses.back().Name = "NoItinerary";
+  SchedClassIdxMap[SchedClasses.back().Name] = 0;
+
+  // Gather and sort all itinerary classes used by instruction descriptions.
+  std::vector<Record*> ItinClassList;
+  for (CodeGenTarget::inst_iterator I = Target.inst_begin(),
+         E = Target.inst_end(); I != E; ++I) {
+    Record *SchedDef = (*I)->TheDef->getValueAsDef("Itinerary");
+    // Map a new SchedClass with no index.
+    if (!SchedClassIdxMap.count(SchedDef->getName())) {
+      SchedClassIdxMap[SchedDef->getName()] = 0;
+      ItinClassList.push_back(SchedDef);
+    }
+  }
+  // Assign each itinerary class unique number, skipping NoItinerary==0
+  NumItineraryClasses = ItinClassList.size();
+  std::sort(ItinClassList.begin(), ItinClassList.end(), LessRecord());
+  for (unsigned i = 0, N = NumItineraryClasses; i < N; i++) {
+    Record *ItinDef = ItinClassList[i];
+    SchedClassIdxMap[ItinDef->getName()] = SchedClasses.size();
+    SchedClasses.push_back(CodeGenSchedClass(ItinDef));
+  }
+
+  // TODO: Infer classes from non-itinerary scheduler resources.
+}
+
+// Gather all processor models.
+void CodeGenSchedModels::CollectProcModels() {
+  std::vector<Record*> ProcRecords =
+    Records.getAllDerivedDefinitions("Processor");
+  std::sort(ProcRecords.begin(), ProcRecords.end(), LessRecordFieldName());
+
+  // Reserve space because we can. Reallocation would be ok.
+  ProcModels.reserve(ProcRecords.size());
+
+  // For each processor, find a unique machine model.
+  for (unsigned i = 0, N = ProcRecords.size(); i < N; ++i)
+    addProcModel(ProcRecords[i]);
+}
+
+// Get a unique processor model based on the defined MachineModel and
+// ProcessorItineraries.
+void CodeGenSchedModels::addProcModel(Record *ProcDef) {
+  unsigned Idx = getProcModelIdx(ProcDef);
+  if (Idx < ProcModels.size())
+    return;
+
+  Record *ModelDef = ProcDef->getValueAsDef("SchedModel");
+  Record *ItinsDef = ProcDef->getValueAsDef("ProcItin");
+
+  std::string ModelName = ModelDef->getName();
+  const std::string &ItinName = ItinsDef->getName();
+
+  bool NoModel = ModelDef->getValueAsBit("NoModel");
+  bool hasTopLevelItin = !ItinsDef->getValueAsListOfDefs("IID").empty();
+  if (NoModel) {
+    // If an itinerary is defined without a machine model, infer a new model.
+    if (NoModel && hasTopLevelItin) {
+      ModelName = ItinName + "Model";
+      ModelDef = NULL;
+    }
+  }
+  else {
+    // If a machine model is defined, the itinerary must be defined within it
+    // rather than in the Processor definition itself.
+    assert(!hasTopLevelItin && "Itinerary must be defined in SchedModel");
+    ItinsDef = ModelDef->getValueAsDef("Itineraries");
+  }
+
+  ProcModelMap[getProcModelKey(ProcDef)]= ProcModels.size();
+
+  ProcModels.push_back(CodeGenProcModel(ModelName, ModelDef, ItinsDef));
+
+  std::vector<Record*> ItinRecords = ItinsDef->getValueAsListOfDefs("IID");
+  CollectProcItin(ProcModels.back(), ItinRecords);
+}
+
+// Gather the processor itineraries.
+void CodeGenSchedModels::CollectProcItin(CodeGenProcModel &ProcModel,
+                                         std::vector<Record*> ItinRecords) {
+  // Skip empty itinerary.
+  if (ItinRecords.empty())
+    return;
+
+  HasProcItineraries = true;
+
+  ProcModel.ItinDefList.resize(NumItineraryClasses+1);
+
+  // Insert each itinerary data record in the correct position within
+  // the processor model's ItinDefList.
+  for (unsigned i = 0, N = ItinRecords.size(); i < N; i++) {
+    Record *ItinData = ItinRecords[i];
+    Record *ItinDef = ItinData->getValueAsDef("TheClass");
+    if (!SchedClassIdxMap.count(ItinDef->getName())) {
+      DEBUG(dbgs() << ProcModel.ItinsDef->getName()
+            << " has unused itinerary class " << ItinDef->getName() << '\n');
+      continue;
+    }
+    ProcModel.ItinDefList[getItinClassIdx(ItinDef)] = ItinData;
+  }
+#ifndef NDEBUG
+  // Check for missing itinerary entries.
+  assert(!ProcModel.ItinDefList[0] && "NoItinerary class can't have rec");
+  for (unsigned i = 1, N = ProcModel.ItinDefList.size(); i < N; ++i) {
+    if (!ProcModel.ItinDefList[i])
+      DEBUG(dbgs() << ProcModel.ItinsDef->getName()
+            << " missing itinerary for class " << SchedClasses[i].Name << '\n');
+  }
+#endif
+}
diff --git a/utils/TableGen/CodeGenSchedule.h b/utils/TableGen/CodeGenSchedule.h
new file mode 100644
index 0000000..9da0145
--- /dev/null
+++ b/utils/TableGen/CodeGenSchedule.h
@@ -0,0 +1,172 @@
+//===- CodeGenSchedule.h - Scheduling Machine Models ------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines structures to encapsulate the machine model as decribed in
+// the target description.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef CODEGEN_SCHEDULE_H
+#define CODEGEN_SCHEDULE_H
+
+#include "llvm/TableGen/Record.h"
+#include "llvm/Support/ErrorHandling.h"
+#include "llvm/ADT/DenseMap.h"
+#include "llvm/ADT/StringMap.h"
+
+namespace llvm {
+
+class CodeGenTarget;
+
+// Scheduling class.
+//
+// Each instruction description will be mapped to a scheduling class. It may be
+// an explicitly defined itinerary class, or an inferred class in which case
+// ItinClassDef == NULL.
+struct CodeGenSchedClass {
+  std::string Name;
+  unsigned Index;
+  Record *ItinClassDef;
+
+  CodeGenSchedClass(): Index(0), ItinClassDef(0) {}
+  CodeGenSchedClass(Record *rec): Index(0), ItinClassDef(rec) {
+    Name = rec->getName();
+  }
+};
+
+// Processor model.
+//
+// ModelName is a unique name used to name an instantiation of MCSchedModel.
+//
+// ModelDef is NULL for inferred Models. This happens when a processor defines
+// an itinerary but no machine model. If the processer defines neither a machine
+// model nor itinerary, then ModelDef remains pointing to NoModel. NoModel has
+// the special "NoModel" field set to true.
+//
+// ItinsDef always points to a valid record definition, but may point to the
+// default NoItineraries. NoItineraries has an empty list of InstrItinData
+// records.
+//
+// ItinDefList orders this processor's InstrItinData records by SchedClass idx.
+struct CodeGenProcModel {
+  std::string ModelName;
+  Record *ModelDef;
+  Record *ItinsDef;
+
+  // Array of InstrItinData records indexed by CodeGenSchedClass::Index.
+  // The list is empty if the subtarget has no itineraries.
+  std::vector<Record *> ItinDefList;
+
+  CodeGenProcModel(const std::string &Name, Record *MDef, Record *IDef):
+    ModelName(Name), ModelDef(MDef), ItinsDef(IDef) {}
+};
+
+// Top level container for machine model data.
+class CodeGenSchedModels {
+  RecordKeeper &Records;
+  const CodeGenTarget &Target;
+
+  // List of unique SchedClasses.
+  std::vector<CodeGenSchedClass> SchedClasses;
+
+  // Map SchedClass name to itinerary index.
+  // These are either explicit itinerary classes or inferred classes.
+  StringMap<unsigned> SchedClassIdxMap;
+
+  // SchedClass indices 1 up to and including NumItineraryClasses identify
+  // itinerary classes that are explicitly used for this target's instruction
+  // definitions. NoItinerary always has index 0 regardless of whether it is
+  // explicitly referenced.
+  //
+  // Any inferred SchedClass have a index greater than NumItineraryClasses.
+  unsigned NumItineraryClasses;
+
+  // List of unique processor models.
+  std::vector<CodeGenProcModel> ProcModels;
+
+  // Map Processor's MachineModel + ProcItin fields to a CodeGenProcModel index.
+  typedef DenseMap<std::pair<Record*, Record*>, unsigned> ProcModelMapTy;
+  ProcModelMapTy ProcModelMap;
+
+  // True if any processors have nonempty itineraries.
+  bool HasProcItineraries;
+
+public:
+  CodeGenSchedModels(RecordKeeper& RK, const CodeGenTarget &TGT);
+
+  // Check if any instructions are assigned to an explicit itinerary class other
+  // than NoItinerary.
+  bool hasItineraryClasses() const { return NumItineraryClasses > 0; }
+
+  // Return the number of itinerary classes in use by this target's instruction
+  // descriptions, not including "NoItinerary".
+  unsigned numItineraryClasses() const {
+    return NumItineraryClasses;
+  }
+
+  // Get a SchedClass from its index.
+  const CodeGenSchedClass &getSchedClass(unsigned Idx) {
+    assert(Idx < SchedClasses.size() && "bad SchedClass index");
+    return SchedClasses[Idx];
+  }
+
+  // Get an itinerary class's index. Value indices are '0' for NoItinerary up to
+  // and including numItineraryClasses().
+  unsigned getItinClassIdx(Record *ItinDef) const {
+    assert(SchedClassIdxMap.count(ItinDef->getName()) && "missing ItinClass");
+    unsigned Idx = SchedClassIdxMap.lookup(ItinDef->getName());
+    assert(Idx <= NumItineraryClasses && "bad ItinClass index");
+    return Idx;
+  }
+
+  bool hasProcessorItineraries() const {
+    return HasProcItineraries;
+  }
+
+  // Get an existing machine model for a processor definition.
+  const CodeGenProcModel &getProcModel(Record *ProcDef) const {
+    unsigned idx = getProcModelIdx(ProcDef);
+    assert(idx < ProcModels.size() && "missing machine model");
+    return ProcModels[idx];
+  }
+
+  // Iterate over the unique processor models.
+  typedef std::vector<CodeGenProcModel>::const_iterator ProcIter;
+  ProcIter procModelBegin() const { return ProcModels.begin(); }
+  ProcIter procModelEnd() const { return ProcModels.end(); }
+
+private:
+  // Get a key that can uniquely identify a machine model.
+  ProcModelMapTy::key_type getProcModelKey(Record *ProcDef) const {
+    Record *ModelDef = ProcDef->getValueAsDef("SchedModel");
+    Record *ItinsDef = ProcDef->getValueAsDef("ProcItin");
+    return std::make_pair(ModelDef, ItinsDef);
+  }
+
+  // Get the unique index of a machine model.
+  unsigned getProcModelIdx(Record *ProcDef) const {
+    ProcModelMapTy::const_iterator I =
+      ProcModelMap.find(getProcModelKey(ProcDef));
+    if (I == ProcModelMap.end())
+      return ProcModels.size();
+    return I->second;
+  }
+
+  // Initialize a new processor model if it is unique.
+  void addProcModel(Record *ProcDef);
+
+  void CollectSchedClasses();
+  void CollectProcModels();
+  void CollectProcItin(CodeGenProcModel &ProcModel,
+                       std::vector<Record*> ItinRecords);
+};
+
+} // namespace llvm
+
+#endif
diff --git a/utils/TableGen/CodeGenTarget.cpp b/utils/TableGen/CodeGenTarget.cpp
index 4bc4c54..1dd2efc 100644
--- a/utils/TableGen/CodeGenTarget.cpp
+++ b/utils/TableGen/CodeGenTarget.cpp
@@ -16,6 +16,7 @@
 
 #include "CodeGenTarget.h"
 #include "CodeGenIntrinsics.h"
+#include "CodeGenSchedule.h"
 #include "llvm/TableGen/Record.h"
 #include "llvm/ADT/StringExtras.h"
 #include "llvm/ADT/STLExtras.h"
@@ -112,7 +113,7 @@ std::string llvm::getQualifiedName(const Record *R) {
 /// getTarget - Return the current instance of the Target class.
 ///
 CodeGenTarget::CodeGenTarget(RecordKeeper &records)
-  : Records(records), RegBank(0) {
+  : Records(records), RegBank(0), SchedModels(0) {
   std::vector<Record*> Targets = Records.getAllDerivedDefinitions("Target");
   if (Targets.size() == 0)
     throw std::string("ERROR: No 'Target' subclasses defined!");
@@ -121,6 +122,10 @@ CodeGenTarget::CodeGenTarget(RecordKeeper &records)
   TargetRec = Targets[0];
 }
 
+CodeGenTarget::~CodeGenTarget() {
+  delete RegBank;
+  delete SchedModels;
+}
 
 const std::string &CodeGenTarget::getName() const {
   return TargetRec->getName();
@@ -235,6 +240,11 @@ void CodeGenTarget::ReadLegalValueTypes() const {
                         LegalValueTypes.end());
 }
 
+CodeGenSchedModels &CodeGenTarget::getSchedModels() const {
+  if (!SchedModels)
+    SchedModels = new CodeGenSchedModels(Records, *this);
+  return *SchedModels;
+}
 
 void CodeGenTarget::ReadInstructions() const {
   std::vector<Record*> Insts = Records.getAllDerivedDefinitions("Instruction");
diff --git a/utils/TableGen/CodeGenTarget.h b/utils/TableGen/CodeGenTarget.h
index 85463da..2f8cee4 100644
--- a/utils/TableGen/CodeGenTarget.h
+++ b/utils/TableGen/CodeGenTarget.h
@@ -26,6 +26,7 @@
 namespace llvm {
 
 struct CodeGenRegister;
+class CodeGenSchedModels;
 class CodeGenTarget;
 
 // SelectionDAG node properties.
@@ -72,9 +73,12 @@ class CodeGenTarget {
   void ReadInstructions() const;
   void ReadLegalValueTypes() const;
 
+  mutable CodeGenSchedModels *SchedModels;
+
   mutable std::vector<const CodeGenInstruction*> InstrsByEnum;
 public:
   CodeGenTarget(RecordKeeper &Records);
+  ~CodeGenTarget();
 
   Record *getTargetRecord() const { return TargetRec; }
   const std::string &getName() const;
@@ -96,7 +100,7 @@ public:
   ///
   Record *getAsmParserVariant(unsigned i) const;
 
-  /// getAsmParserVariantCount - Return the AssmblyParserVariant definition 
+  /// getAsmParserVariantCount - Return the AssmblyParserVariant definition
   /// available for this target.
   ///
   unsigned getAsmParserVariantCount() const;
@@ -139,6 +143,8 @@ public:
     return false;
   }
 
+  CodeGenSchedModels &getSchedModels() const;
+
 private:
   DenseMap<const Record*, CodeGenInstruction*> &getInstructions() const {
     if (Instructions.empty()) ReadInstructions();
diff --git a/utils/TableGen/InstrInfoEmitter.cpp b/utils/TableGen/InstrInfoEmitter.cpp
index 600586f..3adb869 100644
--- a/utils/TableGen/InstrInfoEmitter.cpp
+++ b/utils/TableGen/InstrInfoEmitter.cpp
@@ -14,6 +14,7 @@
 
 
 #include "CodeGenDAGPatterns.h"
+#include "CodeGenSchedule.h"
 #include "CodeGenTarget.h"
 #include "SequenceToOffsetTable.h"
 #include "llvm/ADT/StringExtras.h"
@@ -29,10 +30,11 @@ namespace {
 class InstrInfoEmitter {
   RecordKeeper &Records;
   CodeGenDAGPatterns CDP;
-  std::map<std::string, unsigned> ItinClassMap;
+  const CodeGenSchedModels &SchedModels;
 
 public:
-  InstrInfoEmitter(RecordKeeper &R) : Records(R), CDP(R) { }
+  InstrInfoEmitter(RecordKeeper &R):
+    Records(R), CDP(R), SchedModels(CDP.getTargetInfo().getSchedModels()) {}
 
   // run - Output the instruction set description.
   void run(raw_ostream &OS);
@@ -47,10 +49,6 @@ private:
                   const OperandInfoMapTy &OpInfo,
                   raw_ostream &OS);
 
-  // Itinerary information.
-  void GatherItinClasses();
-  unsigned getItinClassNumber(const Record *InstRec);
-
   // Operand information.
   void EmitOperandInfo(raw_ostream &OS, OperandInfoMapTy &OperandInfoIDs);
   std::vector<std::string> GetOperandInfo(const CodeGenInstruction &Inst);
@@ -66,23 +64,6 @@ static void PrintDefList(const std::vector<Record*> &Uses,
 }
 
 //===----------------------------------------------------------------------===//
-// Instruction Itinerary Information.
-//===----------------------------------------------------------------------===//
-
-void InstrInfoEmitter::GatherItinClasses() {
-  std::vector<Record*> DefList =
-  Records.getAllDerivedDefinitions("InstrItinClass");
-  std::sort(DefList.begin(), DefList.end(), LessRecord());
-
-  for (unsigned i = 0, N = DefList.size(); i < N; i++)
-    ItinClassMap[DefList[i]->getName()] = i;
-}
-
-unsigned InstrInfoEmitter::getItinClassNumber(const Record *InstRec) {
-  return ItinClassMap[InstRec->getValueAsDef("Itinerary")->getName()];
-}
-
-//===----------------------------------------------------------------------===//
 // Operand Info Emission.
 //===----------------------------------------------------------------------===//
 
@@ -202,8 +183,6 @@ void InstrInfoEmitter::run(raw_ostream &OS) {
   emitSourceFileHeader("Target Instruction Enum Values", OS);
   emitEnums(OS);
 
-  GatherItinClasses();
-
   emitSourceFileHeader("Target Instruction Descriptors", OS);
 
   OS << "\n#ifdef GET_INSTRINFO_MC_DESC\n";
@@ -325,10 +304,11 @@ void InstrInfoEmitter::emitRecord(const CodeGenInstruction &Inst, unsigned Num,
     MinOperands = Inst.Operands.back().MIOperandNo +
                   Inst.Operands.back().MINumOperands;
 
+  Record *ItinDef = Inst.TheDef->getValueAsDef("Itinerary");
   OS << "  { ";
   OS << Num << ",\t" << MinOperands << ",\t"
      << Inst.Operands.NumDefs << ",\t"
-     << getItinClassNumber(Inst.TheDef) << ",\t"
+     << SchedModels.getItinClassIdx(ItinDef) << ",\t"
      << Inst.TheDef->getValueAsInt("Size") << ",\t0";
 
   // Emit all of the target indepedent flags...
diff --git a/utils/TableGen/SubtargetEmitter.cpp b/utils/TableGen/SubtargetEmitter.cpp
index 1c37d15..48dbdc2 100644
--- a/utils/TableGen/SubtargetEmitter.cpp
+++ b/utils/TableGen/SubtargetEmitter.cpp
@@ -12,6 +12,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "CodeGenTarget.h"
+#include "CodeGenSchedule.h"
 #include "llvm/ADT/StringExtras.h"
 #include "llvm/MC/MCInstrItineraries.h"
 #include "llvm/Support/Debug.h"
@@ -27,15 +28,12 @@ namespace {
 class SubtargetEmitter {
 
   RecordKeeper &Records;
+  CodeGenSchedModels &SchedModels;
   std::string Target;
-  bool HasItineraries;
 
   void Enumeration(raw_ostream &OS, const char *ClassName, bool isBits);
   unsigned FeatureKeyValues(raw_ostream &OS);
   unsigned CPUKeyValues(raw_ostream &OS);
-  unsigned CollectAllItinClasses(raw_ostream &OS,
-                                 std::map<std::string,unsigned> &ItinClassesMap,
-                                 std::vector<Record*> &ItinClassList);
   void FormItineraryStageString(const std::string &Names,
                                 Record *ItinData, std::string &ItinString,
                                 unsigned &NStages);
@@ -44,22 +42,23 @@ class SubtargetEmitter {
   void FormItineraryBypassString(const std::string &Names,
                                  Record *ItinData,
                                  std::string &ItinString, unsigned NOperandCycles);
-  void EmitStageAndOperandCycleData(raw_ostream &OS, unsigned NItinClasses,
-                     std::map<std::string, unsigned> &ItinClassesMap,
-                     std::vector<Record*> &ItinClassList,
-                     std::vector<std::vector<InstrItinerary> > &ProcList);
-  void EmitItineraryProp(raw_ostream &OS, const Record *R, const char *Name,
+  void EmitStageAndOperandCycleData(raw_ostream &OS,
+                                    std::vector<std::vector<InstrItinerary> >
+                                      &ProcItinLists);
+  void EmitItineraries(raw_ostream &OS,
+                       std::vector<std::vector<InstrItinerary> >
+                         &ProcItinLists);
+  void EmitProcessorProp(raw_ostream &OS, const Record *R, const char *Name,
                          char Separator);
-  void EmitProcessorData(raw_ostream &OS,
-                         std::vector<Record*> &ItinClassList,
-                         std::vector<std::vector<InstrItinerary> > &ProcList);
+  void EmitProcessorModels(raw_ostream &OS);
   void EmitProcessorLookup(raw_ostream &OS);
-  void EmitData(raw_ostream &OS);
+  void EmitSchedModel(raw_ostream &OS);
   void ParseFeaturesFunction(raw_ostream &OS, unsigned NumFeatures,
                              unsigned NumProcs);
 
 public:
-  SubtargetEmitter(RecordKeeper &R) : Records(R), HasItineraries(false) {}
+  SubtargetEmitter(RecordKeeper &R, CodeGenTarget &TGT):
+    Records(R), SchedModels(TGT.getSchedModels()), Target(TGT.getName()) {}
 
   void run(raw_ostream &o);
 
@@ -243,28 +242,6 @@ unsigned SubtargetEmitter::CPUKeyValues(raw_ostream &OS) {
 }
 
 //
-// CollectAllItinClasses - Gathers and enumerates all the itinerary classes.
-// Returns itinerary class count.
-//
-unsigned SubtargetEmitter::
-CollectAllItinClasses(raw_ostream &OS,
-                      std::map<std::string, unsigned> &ItinClassesMap,
-                      std::vector<Record*> &ItinClassList) {
-  // For each itinerary class
-  unsigned N = ItinClassList.size();
-  for (unsigned i = 0; i < N; i++) {
-    // Next itinerary class
-    const Record *ItinClass = ItinClassList[i];
-    // Get name of itinerary class
-    // Assign itinerary class a unique number
-    ItinClassesMap[ItinClass->getName()] = i;
-  }
-
-  // Return itinerary class count
-  return N;
-}
-
-//
 // FormItineraryStageString - Compose a string containing the stage
 // data initialization for the specified itinerary.  N is the number
 // of stages.
@@ -350,32 +327,25 @@ void SubtargetEmitter::FormItineraryBypassString(const std::string &Name,
 }
 
 //
-// EmitStageAndOperandCycleData - Generate unique itinerary stages and
-// operand cycle tables.  Record itineraries for processors.
+// EmitStageAndOperandCycleData - Generate unique itinerary stages and operand
+// cycle tables. Create a list of InstrItinerary objects (ProcItinLists) indexed
+// by CodeGenSchedClass::Index.
 //
-void SubtargetEmitter::EmitStageAndOperandCycleData(raw_ostream &OS,
-       unsigned NItinClasses,
-       std::map<std::string, unsigned> &ItinClassesMap,
-       std::vector<Record*> &ItinClassList,
-       std::vector<std::vector<InstrItinerary> > &ProcList) {
-  // Gather processor iteraries
-  std::vector<Record*> ProcItinList =
-                       Records.getAllDerivedDefinitions("ProcessorItineraries");
-
-  // If just no itinerary then don't bother
-  if (ProcItinList.size() < 2) return;
+void SubtargetEmitter::
+EmitStageAndOperandCycleData(raw_ostream &OS,
+                             std::vector<std::vector<InstrItinerary> >
+                               &ProcItinLists) {
 
   // Emit functional units for all the itineraries.
-  for (unsigned i = 0, N = ProcItinList.size(); i < N; ++i) {
-    // Next record
-    Record *Proc = ProcItinList[i];
+  for (CodeGenSchedModels::ProcIter PI = SchedModels.procModelBegin(),
+         PE = SchedModels.procModelEnd(); PI != PE; ++PI) {
 
-    std::vector<Record*> FUs = Proc->getValueAsListOfDefs("FU");
+    std::vector<Record*> FUs = PI->ItinsDef->getValueAsListOfDefs("FU");
     if (FUs.empty())
       continue;
 
-    const std::string &Name = Proc->getName();
-    OS << "\n// Functional units for itineraries \"" << Name << "\"\n"
+    const std::string &Name = PI->ItinsDef->getName();
+    OS << "\n// Functional units for \"" << Name << "\"\n"
        << "namespace " << Name << "FU {\n";
 
     for (unsigned j = 0, FUN = FUs.size(); j < FUN; ++j)
@@ -384,7 +354,7 @@ void SubtargetEmitter::EmitStageAndOperandCycleData(raw_ostream &OS,
 
     OS << "}\n";
 
-    std::vector<Record*> BPs = Proc->getValueAsListOfDefs("BP");
+    std::vector<Record*> BPs = PI->ItinsDef->getValueAsListOfDefs("BP");
     if (BPs.size()) {
       OS << "\n// Pipeline forwarding pathes for itineraries \"" << Name
          << "\"\n" << "namespace " << Name << "Bypass {\n";
@@ -411,49 +381,56 @@ void SubtargetEmitter::EmitStageAndOperandCycleData(raw_ostream &OS,
   // Begin pipeline bypass table
   std::string BypassTable = "extern const unsigned " + Target +
     "ForwardingPaths[] = {\n";
-  BypassTable += "  0, // No itinerary\n";
+  BypassTable += " 0, // No itinerary\n";
 
+  // For each Itinerary across all processors, add a unique entry to the stages,
+  // operand cycles, and pipepine bypess tables. Then add the new Itinerary
+  // object with computed offsets to the ProcItinLists result.
   unsigned StageCount = 1, OperandCycleCount = 1;
   std::map<std::string, unsigned> ItinStageMap, ItinOperandMap;
-  for (unsigned i = 0, N = ProcItinList.size(); i < N; i++) {
-    // Next record
-    Record *Proc = ProcItinList[i];
-
-    // Get processor itinerary name
-    const std::string &Name = Proc->getName();
+  for (CodeGenSchedModels::ProcIter PI = SchedModels.procModelBegin(),
+         PE = SchedModels.procModelEnd(); PI != PE; ++PI) {
+    const CodeGenProcModel &ProcModel = *PI;
 
-    // Get itinerary data list
-    std::vector<Record*> ItinDataList = Proc->getValueAsListOfDefs("IID");
-    std::vector<InstrItinerary> ItinList;
+    // Add process itinerary to the list.
+    ProcItinLists.resize(ProcItinLists.size()+1);
 
-    // Add an empty itinerary.
-    if (ItinDataList.empty()) {
-      ProcList.push_back(ItinList);
+    // If this processor defines no itineraries, then leave the itinerary list
+    // empty.
+    std::vector<InstrItinerary> &ItinList = ProcItinLists.back();
+    if (ProcModel.ItinDefList.empty())
       continue;
-    }
 
-    // Expand processor itinerary to cover all itinerary classes
-    ItinList.resize(NItinClasses);
+    // Reserve index==0 for NoItinerary.
+    ItinList.resize(SchedModels.numItineraryClasses()+1);
+
+    const std::string &Name = ProcModel.ItinsDef->getName();
 
     // For each itinerary data
-    for (unsigned j = 0, M = ItinDataList.size(); j < M; j++) {
+    for (unsigned SchedClassIdx = 0,
+           SchedClassEnd = ProcModel.ItinDefList.size();
+         SchedClassIdx < SchedClassEnd; ++SchedClassIdx) {
+
       // Next itinerary data
-      Record *ItinData = ItinDataList[j];
+      Record *ItinData = ProcModel.ItinDefList[SchedClassIdx];
 
       // Get string and stage count
       std::string ItinStageString;
-      unsigned NStages;
-      FormItineraryStageString(Name, ItinData, ItinStageString, NStages);
+      unsigned NStages = 0;
+      if (ItinData)
+        FormItineraryStageString(Name, ItinData, ItinStageString, NStages);
 
       // Get string and operand cycle count
       std::string ItinOperandCycleString;
-      unsigned NOperandCycles;
-      FormItineraryOperandCycleString(ItinData, ItinOperandCycleString,
-                                      NOperandCycles);
-
+      unsigned NOperandCycles = 0;
       std::string ItinBypassString;
-      FormItineraryBypassString(Name, ItinData, ItinBypassString,
-                                NOperandCycles);
+      if (ItinData) {
+        FormItineraryOperandCycleString(ItinData, ItinOperandCycleString,
+                                        NOperandCycles);
+
+        FormItineraryBypassString(Name, ItinData, ItinBypassString,
+                                  NOperandCycles);
+      }
 
       // Check to see if stage already exists and create if it doesn't
       unsigned FindStage = 0;
@@ -493,33 +470,26 @@ void SubtargetEmitter::EmitStageAndOperandCycleData(raw_ostream &OS,
         }
       }
 
-      // Locate where to inject into processor itinerary table
-      const std::string &Name = ItinData->getValueAsDef("TheClass")->getName();
-      unsigned Find = ItinClassesMap[Name];
-
       // Set up itinerary as location and location + stage count
-      int NumUOps = ItinData->getValueAsInt("NumMicroOps");
+      int NumUOps = ItinData ? ItinData->getValueAsInt("NumMicroOps") : 0;
       InstrItinerary Intinerary = { NumUOps, FindStage, FindStage + NStages,
                                     FindOperandCycle,
                                     FindOperandCycle + NOperandCycles};
 
       // Inject - empty slots will be 0, 0
-      ItinList[Find] = Intinerary;
+      ItinList[SchedClassIdx] = Intinerary;
     }
-
-    // Add process itinerary to list
-    ProcList.push_back(ItinList);
   }
 
   // Closing stage
-  StageTable += "  { 0, 0, 0, llvm::InstrStage::Required } // End itinerary\n";
+  StageTable += "  { 0, 0, 0, llvm::InstrStage::Required } // End stages\n";
   StageTable += "};\n";
 
   // Closing operand cycles
-  OperandCycleTable += "  0 // End itinerary\n";
+  OperandCycleTable += "  0 // End operand cycles\n";
   OperandCycleTable += "};\n";
 
-  BypassTable += "  0 // End itinerary\n";
+  BypassTable += " 0 // End bypass tables\n";
   BypassTable += "};\n";
 
   // Emit tables.
@@ -528,92 +498,94 @@ void SubtargetEmitter::EmitStageAndOperandCycleData(raw_ostream &OS,
   OS << BypassTable;
 }
 
-void SubtargetEmitter::EmitItineraryProp(raw_ostream &OS, const Record *R,
-                                         const char *Name, char Separator) {
-  OS << "  ";
-  int V = R->getValueAsInt(Name);
-  if (V >= 0)
-    OS << V << Separator << " // " << Name;
-  else
-    OS << "InstrItineraryProps::Default" << Name << Separator;
-  OS << '\n';
-}
-
 //
-// EmitProcessorData - Generate data for processor itineraries.
+// EmitProcessorData - Generate data for processor itineraries that were
+// computed during EmitStageAndOperandCycleData(). ProcItinLists lists all
+// Itineraries for each processor. The Itinerary lists are indexed on
+// CodeGenSchedClass::Index.
 //
 void SubtargetEmitter::
-EmitProcessorData(raw_ostream &OS,
-                  std::vector<Record*> &ItinClassList,
-                  std::vector<std::vector<InstrItinerary> > &ProcList) {
+EmitItineraries(raw_ostream &OS,
+                std::vector<std::vector<InstrItinerary> > &ProcItinLists) {
 
-  // Get an iterator for processor itinerary stages
+  // For each processor's machine model
   std::vector<std::vector<InstrItinerary> >::iterator
-      ProcListIter = ProcList.begin();
-
-  // For each processor itinerary
-  std::vector<Record*> Itins =
-                       Records.getAllDerivedDefinitions("ProcessorItineraries");
-  for (unsigned i = 0, N = Itins.size(); i < N; i++) {
-    // Next record
-    Record *Itin = Itins[i];
+      ProcItinListsIter = ProcItinLists.begin();
+  for (CodeGenSchedModels::ProcIter PI = SchedModels.procModelBegin(),
+         PE = SchedModels.procModelEnd(); PI != PE; ++PI) {
+    Record *ItinsDef = PI->ItinsDef;
 
     // Get processor itinerary name
-    const std::string &Name = Itin->getName();
+    const std::string &Name = ItinsDef->getName();
 
-    // Skip default
-    // Begin processor itinerary properties
-    OS << "\n";
-    OS << "static const llvm::InstrItineraryProps " << Name << "Props(\n";
-    EmitItineraryProp(OS, Itin, "IssueWidth", ',');
-    EmitItineraryProp(OS, Itin, "MinLatency", ',');
-    EmitItineraryProp(OS, Itin, "LoadLatency", ',');
-    EmitItineraryProp(OS, Itin, "HighLatency", ' ');
-    OS << ");\n";
+    // Get the itinerary list for the processor.
+    assert(ProcItinListsIter != ProcItinLists.end() && "bad iterator");
+    std::vector<InstrItinerary> &ItinList = *ProcItinListsIter++;
 
-    // For each itinerary class
-    std::vector<InstrItinerary> &ItinList = *ProcListIter++;
-    if (!ItinList.empty()) {
-      assert(ItinList.size() == ItinClassList.size() && "bad itinerary");
+    OS << "\n";
+    OS << "static const llvm::InstrItinerary ";
+    if (ItinList.empty()) {
+      OS << '*' << Name << " = 0;\n";
+      continue;
+    }
 
-      // Begin processor itinerary table
-      OS << "\n";
-      OS << "static const llvm::InstrItinerary " << Name << "Entries"
-         << "[] = {\n";
-
-      for (unsigned j = 0, M = ItinList.size(); j < M; ++j) {
-        InstrItinerary &Intinerary = ItinList[j];
-
-        // Emit in the form of
-        // { firstStage, lastStage, firstCycle, lastCycle } // index
-        if (Intinerary.FirstStage == 0) {
-          OS << "  { 1, 0, 0, 0, 0 }";
-        } else {
-          OS << "  { " <<
-            Intinerary.NumMicroOps << ", " <<
-            Intinerary.FirstStage << ", " <<
-            Intinerary.LastStage << ", " <<
-            Intinerary.FirstOperandCycle << ", " <<
-            Intinerary.LastOperandCycle << " }";
-        }
-        OS << ", // " << j << " " << ItinClassList[j]->getName() << "\n";
-      }
-      // End processor itinerary table
-      OS << "  { 1, ~0U, ~0U, ~0U, ~0U } // end marker\n";
-      OS << "};\n";
+    // Begin processor itinerary table
+    OS << Name << "[] = {\n";
+
+    // For each itinerary class in CodeGenSchedClass::Index order.
+    for (unsigned j = 0, M = ItinList.size(); j < M; ++j) {
+      InstrItinerary &Intinerary = ItinList[j];
+
+      // Emit Itinerary in the form of
+      // { firstStage, lastStage, firstCycle, lastCycle } // index
+      OS << "  { " <<
+        Intinerary.NumMicroOps << ", " <<
+        Intinerary.FirstStage << ", " <<
+        Intinerary.LastStage << ", " <<
+        Intinerary.FirstOperandCycle << ", " <<
+        Intinerary.LastOperandCycle << " }" <<
+        ", // " << j << " " << SchedModels.getSchedClass(j).Name << "\n";
     }
-    OS << '\n';
-    OS << "static const llvm::InstrItinerarySubtargetValue "
-       << Name << " = {\n";
-    OS << "  &" << Name << "Props,\n";
-    if (ItinList.empty())
-      OS << "  0\n";
-    else
-      OS << "  " << Name << "Entries\n";
+    // End processor itinerary table
+    OS << "  { 0, ~0U, ~0U, ~0U, ~0U } // end marker\n";
     OS << "};\n";
   }
 }
 
+// Emit either the the value defined in the TableGen Record, or the default
+// value defined in the C++ header. The Record is null if the processor does not
+// define a model.
+void SubtargetEmitter::EmitProcessorProp(raw_ostream &OS, const Record *R,
+                                         const char *Name, char Separator) {
+  OS << "  ";
+  int V = R ? R->getValueAsInt(Name) : -1;
+  if (V >= 0)
+    OS << V << Separator << " // " << Name;
+  else
+    OS << "MCSchedModel::Default" << Name << Separator;
+  OS << '\n';
+}
+
+void SubtargetEmitter::EmitProcessorModels(raw_ostream &OS) {
+  // For each processor model.
+  for (CodeGenSchedModels::ProcIter PI = SchedModels.procModelBegin(),
+         PE = SchedModels.procModelEnd(); PI != PE; ++PI) {
+    // Skip default
+    // Begin processor itinerary properties
+    OS << "\n";
+    OS << "static const llvm::MCSchedModel " << PI->ModelName << "(\n";
+    EmitProcessorProp(OS, PI->ModelDef, "IssueWidth", ',');
+    EmitProcessorProp(OS, PI->ModelDef, "MinLatency", ',');
+    EmitProcessorProp(OS, PI->ModelDef, "LoadLatency", ',');
+    EmitProcessorProp(OS, PI->ModelDef, "HighLatency", ',');
+    if (SchedModels.hasItineraryClasses())
+      OS << "  " << PI->ItinsDef->getName();
+    else
+      OS << "  0";
+    OS << ");\n";
+  }
+}
+
 //
 // EmitProcessorLookup - generate cpu name to itinerary lookup table.
 //
@@ -627,7 +599,7 @@ void SubtargetEmitter::EmitProcessorLookup(raw_ostream &OS) {
   OS << "\n";
   OS << "// Sorted (by key) array of itineraries for CPU subtype.\n"
      << "extern const llvm::SubtargetInfoKV "
-     << Target << "ProcItinKV[] = {\n";
+     << Target << "ProcSchedKV[] = {\n";
 
   // For each processor
   for (unsigned i = 0, N = ProcessorList.size(); i < N;) {
@@ -635,13 +607,13 @@ void SubtargetEmitter::EmitProcessorLookup(raw_ostream &OS) {
     Record *Processor = ProcessorList[i];
 
     const std::string &Name = Processor->getValueAsString("Name");
-    const std::string &ProcItin =
-      Processor->getValueAsDef("ProcItin")->getName();
+    const std::string &ProcModelName =
+      SchedModels.getProcModel(Processor).ModelName;
 
     // Emit as { "cpu", procinit },
     OS << "  { "
        << "\"" << Name << "\", "
-       << "(void *)&" << ProcItin;
+       << "(void *)&" << ProcModelName;
 
     OS << " }";
 
@@ -656,31 +628,19 @@ void SubtargetEmitter::EmitProcessorLookup(raw_ostream &OS) {
 }
 
 //
-// EmitData - Emits all stages and itineries, folding common patterns.
+// EmitSchedModel - Emits all scheduling model tables, folding common patterns.
 //
-void SubtargetEmitter::EmitData(raw_ostream &OS) {
-  std::map<std::string, unsigned> ItinClassesMap;
-  // Gather and sort all itinerary classes
-  std::vector<Record*> ItinClassList =
-    Records.getAllDerivedDefinitions("InstrItinClass");
-  std::sort(ItinClassList.begin(), ItinClassList.end(), LessRecord());
-
-  // Enumerate all the itinerary classes
-  unsigned NItinClasses = CollectAllItinClasses(OS, ItinClassesMap,
-                                                ItinClassList);
-  // Make sure the rest is worth the effort
-  HasItineraries = NItinClasses != 1;   // Ignore NoItinerary.
-
-  if (HasItineraries) {
-    std::vector<std::vector<InstrItinerary> > ProcList;
+void SubtargetEmitter::EmitSchedModel(raw_ostream &OS) {
+  if (SchedModels.hasItineraryClasses()) {
+    std::vector<std::vector<InstrItinerary> > ProcItinLists;
     // Emit the stage data
-    EmitStageAndOperandCycleData(OS, NItinClasses, ItinClassesMap,
-                                 ItinClassList, ProcList);
-    // Emit the processor itinerary data
-    EmitProcessorData(OS, ItinClassList, ProcList);
-    // Emit the processor lookup data
-    EmitProcessorLookup(OS);
+    EmitStageAndOperandCycleData(OS, ProcItinLists);
+    EmitItineraries(OS, ProcItinLists);
   }
+  // Emit the processor machine model
+  EmitProcessorModels(OS);
+  // Emit the processor lookup data
+  EmitProcessorLookup(OS);
 }
 
 //
@@ -734,8 +694,6 @@ void SubtargetEmitter::ParseFeaturesFunction(raw_ostream &OS,
 // SubtargetEmitter::run - Main subtarget enumeration emitter.
 //
 void SubtargetEmitter::run(raw_ostream &OS) {
-  Target = CodeGenTarget(Records).getName();
-
   emitSourceFileHeader("Subtarget Enumeration Source Fragment", OS);
 
   OS << "\n#ifdef GET_SUBTARGETINFO_ENUM\n";
@@ -757,7 +715,7 @@ void SubtargetEmitter::run(raw_ostream &OS) {
   OS << "\n";
   unsigned NumProcs = CPUKeyValues(OS);
   OS << "\n";
-  EmitData(OS);
+  EmitSchedModel(OS);
   OS << "\n";
 #if 0
   OS << "}\n";
@@ -776,8 +734,8 @@ void SubtargetEmitter::run(raw_ostream &OS) {
     OS << Target << "SubTypeKV, ";
   else
     OS << "0, ";
-  if (HasItineraries) {
-    OS << Target << "ProcItinKV, "
+  if (SchedModels.hasItineraryClasses()) {
+    OS << Target << "ProcSchedKV, "
        << Target << "Stages, "
        << Target << "OperandCycles, "
        << Target << "ForwardingPaths, ";
@@ -822,8 +780,8 @@ void SubtargetEmitter::run(raw_ostream &OS) {
   OS << "namespace llvm {\n";
   OS << "extern const llvm::SubtargetFeatureKV " << Target << "FeatureKV[];\n";
   OS << "extern const llvm::SubtargetFeatureKV " << Target << "SubTypeKV[];\n";
-  if (HasItineraries) {
-    OS << "extern const llvm::SubtargetInfoKV " << Target << "ProcItinKV[];\n";
+  if (SchedModels.hasItineraryClasses()) {
+    OS << "extern const llvm::SubtargetInfoKV " << Target << "ProcSchedKV[];\n";
     OS << "extern const llvm::InstrStage " << Target << "Stages[];\n";
     OS << "extern const unsigned " << Target << "OperandCycles[];\n";
     OS << "extern const unsigned " << Target << "ForwardingPaths[];\n";
@@ -841,8 +799,8 @@ void SubtargetEmitter::run(raw_ostream &OS) {
     OS << Target << "SubTypeKV, ";
   else
     OS << "0, ";
-  if (HasItineraries) {
-    OS << Target << "ProcItinKV, "
+  if (SchedModels.hasItineraryClasses()) {
+    OS << Target << "ProcSchedKV, "
        << Target << "Stages, "
        << Target << "OperandCycles, "
        << Target << "ForwardingPaths, ";
@@ -857,7 +815,8 @@ void SubtargetEmitter::run(raw_ostream &OS) {
 namespace llvm {
 
 void EmitSubtarget(RecordKeeper &RK, raw_ostream &OS) {
-  SubtargetEmitter(RK).run(OS);
+  CodeGenTarget CGTarget(RK);
+  SubtargetEmitter(RK, CGTarget).run(OS);
 }
 
 } // End llvm namespace