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

27 files changed, 904 insertions, 502 deletions

diff --git a/include/llvm/MC/MCInstrItineraries.h b/include/llvm/MC/MCInstrItineraries.h
index d8587068ae..65d1559ac6 100644
--- a/include/llvm/MC/MCInstrItineraries.h
+++ b/include/llvm/MC/MCInstrItineraries.h
@@ -16,6 +16,7 @@
 #ifndef LLVM_MC_MCINSTRITINERARIES_H
 #define LLVM_MC_MCINSTRITINERARIES_H
 
+#include "llvm/MC/MCSchedule.h"
 #include <algorithm>
 
 namespace llvm {
@@ -104,81 +105,12 @@ struct InstrItinerary {
 
 
 //===----------------------------------------------------------------------===//
-/// Instruction itinerary properties - These properties provide general
-/// information about the microarchitecture to the scheduler.
-///
-struct InstrItineraryProps {
-  // IssueWidth is the maximum number of instructions that may be scheduled in
-  // the same per-cycle group.
-  unsigned IssueWidth;
-  static const unsigned DefaultIssueWidth = 1;
-
-  // MinLatency is the minimum latency between a register write
-  // followed by a data dependent read. This determines which
-  // instructions may be scheduled in the same per-cycle group. This
-  // is distinct from *expected* latency, which determines the likely
-  // critical path but does not guarantee a pipeline
-  // hazard. MinLatency can always be overridden by the number of
-  // InstrStage cycles.
-  //
-  // (-1) Standard in-order processor.
-  //      Use InstrItinerary OperandCycles as MinLatency.
-  //      If no OperandCycles exist, then use the cycle of the last InstrStage.
-  //
-  //  (0) Out-of-order processor, or in-order with bundled dependencies.
-  //      RAW dependencies may be dispatched in the same cycle.
-  //      Optional InstrItinerary OperandCycles provides expected latency.
-  //
-  // (>0) In-order processor with variable latencies.
-  //      Use the greater of this value or the cycle of the last InstrStage.
-  //      Optional InstrItinerary OperandCycles provides expected latency.
-  //      TODO: can't yet specify both min and expected latency per operand.
-  int MinLatency;
-  static const unsigned DefaultMinLatency = -1;
-
-  // LoadLatency is the expected latency of load instructions.
-  //
-  // If MinLatency >= 0, this may be overriden for individual load opcodes by
-  // InstrItinerary OperandCycles.
-  unsigned LoadLatency;
-  static const unsigned DefaultLoadLatency = 4;
-
-  // HighLatency is the expected latency of "very high latency" operations.
-  // See TargetInstrInfo::isHighLatencyDef().
-  // By default, this is set to an arbitrarily high number of cycles
-  // likely to have some impact on scheduling heuristics.
-  // If MinLatency >= 0, this may be overriden by InstrItinData OperandCycles.
-  unsigned HighLatency;
-  static const unsigned DefaultHighLatency = 10;
-
-  // Default's must be specified as static const literals so that tablegenerated
-  // target code can use it in static initializers. The defaults need to be
-  // initialized in this default ctor because some clients directly instantiate
-  // InstrItineraryData instead of using a generated itinerary.
-  InstrItineraryProps(): IssueWidth(DefaultMinLatency),
-                         MinLatency(DefaultMinLatency),
-                         LoadLatency(DefaultLoadLatency),
-                         HighLatency(DefaultHighLatency) {}
-
-  InstrItineraryProps(unsigned iw, int ml, unsigned ll, unsigned hl):
-    IssueWidth(iw), MinLatency(ml), LoadLatency(ll), HighLatency(hl) {}
-};
-
-//===----------------------------------------------------------------------===//
-/// Encapsulate all subtarget specific information for scheduling for use with
-/// SubtargetInfoKV.
-struct InstrItinerarySubtargetValue {
-  const InstrItineraryProps *Props;
-  const InstrItinerary *Itineraries;
-};
-
-//===----------------------------------------------------------------------===//
 /// Instruction itinerary Data - Itinerary data supplied by a subtarget to be
 /// used by a target.
 ///
 class InstrItineraryData {
 public:
-  InstrItineraryProps Props;
+  const MCSchedModel   *SchedModel;     ///< Basic machine properties.
   const InstrStage     *Stages;         ///< Array of stages selected
   const unsigned       *OperandCycles;  ///< Array of operand cycles selected
   const unsigned       *Forwardings;    ///< Array of pipeline forwarding pathes
@@ -186,13 +118,14 @@ public:
 
   /// Ctors.
   ///
-  InstrItineraryData() : Stages(0), OperandCycles(0), Forwardings(0),
-                         Itineraries(0) {}
+  InstrItineraryData() : SchedModel(&MCSchedModel::DefaultSchedModel),
+                         Stages(0), OperandCycles(0),
+                         Forwardings(0), Itineraries(0) {}
 
-  InstrItineraryData(const InstrItineraryProps *P, const InstrStage *S,
-                     const unsigned *OS, const unsigned *F,
-                     const InstrItinerary *I)
-    : Props(*P), Stages(S), OperandCycles(OS), Forwardings(F), Itineraries(I) {}
+  InstrItineraryData(const MCSchedModel *SM, const InstrStage *S,
+                     const unsigned *OS, const unsigned *F)
+    : SchedModel(SM), Stages(S), OperandCycles(OS), Forwardings(F),
+      Itineraries(SchedModel->InstrItineraries) {}
 
   /// isEmpty - Returns true if there are no itineraries.
   ///
@@ -232,13 +165,9 @@ public:
   /// then it defaults to one cycle.
   unsigned getStageLatency(unsigned ItinClassIndx) const {
     // If the target doesn't provide itinerary information, use a simple
-    // non-zero default value for all instructions.  Some target's provide a
-    // dummy (Generic) itinerary which should be handled as if it's itinerary is
-    // empty. We identify this by looking for a reference to stage zero (invalid
-    // stage). This is different from beginStage == endStage != 0, which could
-    // be used for zero-latency pseudo ops.
-    if (isEmpty() || Itineraries[ItinClassIndx].FirstStage == 0)
-      return (Props.MinLatency < 0) ? 1 : Props.MinLatency;
+    // non-zero default value for all instructions.
+    if (isEmpty())
+      return SchedModel->MinLatency < 0 ? 1 : SchedModel->MinLatency;
 
     // Calculate the maximum completion time for any stage.
     unsigned Latency = 0, StartCycle = 0;
diff --git a/include/llvm/MC/MCSchedule.h b/include/llvm/MC/MCSchedule.h
new file mode 100644
index 0000000000..49e3fee9c2
--- /dev/null
+++ b/include/llvm/MC/MCSchedule.h
@@ -0,0 +1,108 @@
+//===-- llvm/MC/MCSchedule.h - Scheduling -----------------------*- 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 the classes used to describe a subtarget's machine model
+// for scheduling and other instruction cost heuristics.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_MC_MCSCHEDMODEL_H
+#define LLVM_MC_MCSCHEDMODEL_H
+
+#include "llvm/Support/DataTypes.h"
+
+namespace llvm {
+
+struct InstrItinerary;
+
+/// Machine model for scheduling, bundling, and heuristics.
+///
+/// The machine model directly provides basic information about the
+/// microarchitecture to the scheduler in the form of properties. It also
+/// optionally refers to scheduler resources tables and itinerary
+/// tables. Scheduler resources tables model the latency and cost for each
+/// instruction type. Itinerary tables are an independant mechanism that
+/// provides a detailed reservation table describing each cycle of instruction
+/// execution. Subtargets may define any or all of the above categories of data
+/// depending on the type of CPU and selected scheduler.
+class MCSchedModel {
+public:
+  static MCSchedModel DefaultSchedModel; // For unknown processors.
+
+  // IssueWidth is the maximum number of instructions that may be scheduled in
+  // the same per-cycle group.
+  unsigned IssueWidth;
+  static const unsigned DefaultIssueWidth = 1;
+
+  // MinLatency is the minimum latency between a register write
+  // followed by a data dependent read. This determines which
+  // instructions may be scheduled in the same per-cycle group. This
+  // is distinct from *expected* latency, which determines the likely
+  // critical path but does not guarantee a pipeline
+  // hazard. MinLatency can always be overridden by the number of
+  // InstrStage cycles.
+  //
+  // (-1) Standard in-order processor.
+  //      Use InstrItinerary OperandCycles as MinLatency.
+  //      If no OperandCycles exist, then use the cycle of the last InstrStage.
+  //
+  //  (0) Out-of-order processor, or in-order with bundled dependencies.
+  //      RAW dependencies may be dispatched in the same cycle.
+  //      Optional InstrItinerary OperandCycles provides expected latency.
+  //
+  // (>0) In-order processor with variable latencies.
+  //      Use the greater of this value or the cycle of the last InstrStage.
+  //      Optional InstrItinerary OperandCycles provides expected latency.
+  //      TODO: can't yet specify both min and expected latency per operand.
+  int MinLatency;
+  static const unsigned DefaultMinLatency = -1;
+
+  // LoadLatency is the expected latency of load instructions.
+  //
+  // If MinLatency >= 0, this may be overriden for individual load opcodes by
+  // InstrItinerary OperandCycles.
+  unsigned LoadLatency;
+  static const unsigned DefaultLoadLatency = 4;
+
+  // HighLatency is the expected latency of "very high latency" operations.
+  // See TargetInstrInfo::isHighLatencyDef().
+  // By default, this is set to an arbitrarily high number of cycles
+  // likely to have some impact on scheduling heuristics.
+  // If MinLatency >= 0, this may be overriden by InstrItinData OperandCycles.
+  unsigned HighLatency;
+  static const unsigned DefaultHighLatency = 10;
+
+private:
+  // TODO: Add a reference to proc resource types and sched resource tables.
+
+  // Instruction itinerary tables used by InstrItineraryData.
+  friend class InstrItineraryData;
+  const InstrItinerary *InstrItineraries;
+
+public:
+  // Default's must be specified as static const literals so that tablegenerated
+  // target code can use it in static initializers. The defaults need to be
+  // initialized in this default ctor because some clients directly instantiate
+  // MCSchedModel instead of using a generated itinerary.
+  MCSchedModel(): IssueWidth(DefaultMinLatency),
+                  MinLatency(DefaultMinLatency),
+                  LoadLatency(DefaultLoadLatency),
+                  HighLatency(DefaultHighLatency),
+                  InstrItineraries(0) {}
+
+  // Table-gen driven ctor.
+  MCSchedModel(unsigned iw, int ml, unsigned ll, unsigned hl,
+               const InstrItinerary *ii):
+    IssueWidth(iw), MinLatency(ml), LoadLatency(ll), HighLatency(hl),
+    InstrItineraries(ii){}
+};
+
+} // End llvm namespace
+
+#endif
diff --git a/include/llvm/MC/MCSubtargetInfo.h b/include/llvm/MC/MCSubtargetInfo.h
index 82730d469e..31d632de60 100644
--- a/include/llvm/MC/MCSubtargetInfo.h
+++ b/include/llvm/MC/MCSubtargetInfo.h
@@ -30,9 +30,9 @@ class MCSubtargetInfo {
   std::string TargetTriple;            // Target triple
   const SubtargetFeatureKV *ProcFeatures;  // Processor feature list
   const SubtargetFeatureKV *ProcDesc;  // Processor descriptions
-  const SubtargetInfoKV *ProcItins;    // Scheduling itineraries
-  const InstrStage *Stages;            // Instruction stages
-  const unsigned *OperandCycles;       // Operand cycles
+  const SubtargetInfoKV *ProcSchedModel; // Scheduler machine model
+  const InstrStage *Stages;            // Instruction itinerary stages
+  const unsigned *OperandCycles;       // Itinerary operand cycles
   const unsigned *ForwardingPaths;     // Forwarding paths
   unsigned NumFeatures;                // Number of processor features
   unsigned NumProcs;                   // Number of processors
@@ -42,7 +42,8 @@ public:
   void InitMCSubtargetInfo(StringRef TT, StringRef CPU, StringRef FS,
                            const SubtargetFeatureKV *PF,
                            const SubtargetFeatureKV *PD,
-                           const SubtargetInfoKV *PI, const InstrStage *IS,
+                           const SubtargetInfoKV *ProcSched,
+                           const InstrStage *IS,
                            const unsigned *OC, const unsigned *FP,
                            unsigned NF, unsigned NP);
 
@@ -69,6 +70,10 @@ public:
   /// bits. This version will also change all implied bits.
   uint64_t ToggleFeature(StringRef FS);
 
+  /// getSchedModelForCPU - Get the machine model of a CPU.
+  ///
+  MCSchedModel *getSchedModelForCPU(StringRef CPU) const;
+
   /// getInstrItineraryForCPU - Get scheduling itinerary of a CPU.
   ///
   InstrItineraryData getInstrItineraryForCPU(StringRef CPU) const;
diff --git a/include/llvm/Target/Target.td b/include/llvm/Target/Target.td
index 5227bab4cf..440cf65d47 100644
--- a/include/llvm/Target/Target.td
+++ b/include/llvm/Target/Target.td
@@ -933,6 +933,10 @@ class Processor<string n, ProcessorItineraries pi, list<SubtargetFeature> f> {
   //
   string Name = n;
 
+  // SchedModel - The machine model for scheduling and instruction cost.
+  //
+  SchedMachineModel SchedModel = NoSchedModel;
+
   // ProcItin - The scheduling information for the target processor.
   //
   ProcessorItineraries ProcItin = pi;
@@ -941,6 +945,14 @@ class Processor<string n, ProcessorItineraries pi, list<SubtargetFeature> f> {
   list<SubtargetFeature> Features = f;
 }
 
+// ProcessorModel allows subtargets to specify the more general
+// SchedMachineModel instead if a ProcessorItinerary. Subtargets will
+// gradually move to this newer form.
+class ProcessorModel<string n, SchedMachineModel m, list<SubtargetFeature> f>
+  : Processor<n, NoItineraries, f> {
+  let SchedModel = m;
+}
+
 //===----------------------------------------------------------------------===//
 // Pull in the common support for calling conventions.
 //
diff --git a/include/llvm/Target/TargetItinerary.td b/include/llvm/Target/TargetItinerary.td
new file mode 100644
index 0000000000..cc74006dc9
--- /dev/null
+++ b/include/llvm/Target/TargetItinerary.td
@@ -0,0 +1,136 @@
+//===- TargetItinerary.td - Target Itinierary Description --*- tablegen -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines the target-independent scheduling interfaces
+// which should be implemented by each target that uses instruction
+// itineraries for scheduling. Itineraries are details reservation
+// tables for each instruction class. They are most appropriate for
+// in-order machine with complicated scheduling or bundling constraints.
+//
+//===----------------------------------------------------------------------===//
+
+//===----------------------------------------------------------------------===//
+// Processor functional unit - These values represent the function units
+// available across all chip sets for the target.  Eg., IntUnit, FPUnit, ...
+// These may be independent values for each chip set or may be shared across
+// all chip sets of the target.  Each functional unit is treated as a resource
+// during scheduling and has an affect instruction order based on availability
+// during a time interval.
+//
+class FuncUnit;
+
+//===----------------------------------------------------------------------===//
+// Pipeline bypass / forwarding - These values specifies the symbolic names of
+// pipeline bypasses which can be used to forward results of instructions
+// that are forwarded to uses.
+class Bypass;
+def NoBypass : Bypass;
+
+class ReservationKind<bits<1> val> {
+  int Value = val;
+}
+
+def Required : ReservationKind<0>;
+def Reserved : ReservationKind<1>;
+
+//===----------------------------------------------------------------------===//
+// Instruction stage - These values represent a non-pipelined step in
+// the execution of an instruction.  Cycles represents the number of
+// discrete time slots needed to complete the stage.  Units represent
+// the choice of functional units that can be used to complete the
+// stage.  Eg. IntUnit1, IntUnit2. NextCycles indicates how many
+// cycles should elapse from the start of this stage to the start of
+// the next stage in the itinerary.  For example:
+//
+// A stage is specified in one of two ways:
+//
+//   InstrStage<1, [FU_x, FU_y]>     - TimeInc defaults to Cycles
+//   InstrStage<1, [FU_x, FU_y], 0>  - TimeInc explicit
+//
+
+class InstrStage<int cycles, list<FuncUnit> units,
+                 int timeinc = -1,
+                 ReservationKind kind = Required> {
+  int Cycles          = cycles;       // length of stage in machine cycles
+  list<FuncUnit> Units = units;       // choice of functional units
+  int TimeInc         = timeinc;      // cycles till start of next stage
+  int Kind            = kind.Value;   // kind of FU reservation
+}
+
+//===----------------------------------------------------------------------===//
+// Instruction itinerary - An itinerary represents a sequential series of steps
+// required to complete an instruction.  Itineraries are represented as lists of
+// instruction stages.
+//
+
+//===----------------------------------------------------------------------===//
+// Instruction itinerary classes - These values represent 'named' instruction
+// itinerary.  Using named itineraries simplifies managing groups of
+// instructions across chip sets.  An instruction uses the same itinerary class
+// across all chip sets.  Thus a new chip set can be added without modifying
+// instruction information.
+//
+class InstrItinClass;
+def NoItinerary : InstrItinClass;
+
+//===----------------------------------------------------------------------===//
+// Instruction itinerary data - These values provide a runtime map of an
+// instruction itinerary class (name) to its itinerary data.
+//
+// NumMicroOps represents the number of micro-operations that each instruction
+// in the class are decoded to. If the number is zero, then it means the
+// instruction can decode into variable number of micro-ops and it must be
+// determined dynamically. This directly relates to the itineraries
+// global IssueWidth property, which constrains the number of microops
+// that can issue per cycle.
+//
+// OperandCycles are optional "cycle counts". They specify the cycle after
+// instruction issue the values which correspond to specific operand indices
+// are defined or read. Bypasses are optional "pipeline forwarding pathes", if
+// a def by an instruction is available on a specific bypass and the use can
+// read from the same bypass, then the operand use latency is reduced by one.
+//
+//  InstrItinData<IIC_iLoad_i , [InstrStage<1, [A9_Pipe1]>,
+//                               InstrStage<1, [A9_AGU]>],
+//                              [3, 1], [A9_LdBypass]>,
+//  InstrItinData<IIC_iMVNr   , [InstrStage<1, [A9_Pipe0, A9_Pipe1]>],
+//                              [1, 1], [NoBypass, A9_LdBypass]>,
+//
+// In this example, the instruction of IIC_iLoadi reads its input on cycle 1
+// (after issue) and the result of the load is available on cycle 3. The result
+// is available via forwarding path A9_LdBypass. If it's used by the first
+// source operand of instructions of IIC_iMVNr class, then the operand latency
+// is reduced by 1.
+class InstrItinData<InstrItinClass Class, list<InstrStage> stages,
+                    list<int> operandcycles = [],
+                    list<Bypass> bypasses = [], int uops = 1> {
+  InstrItinClass TheClass = Class;
+  int NumMicroOps = uops;
+  list<InstrStage> Stages = stages;
+  list<int> OperandCycles = operandcycles;
+  list<Bypass> Bypasses = bypasses;
+}
+
+//===----------------------------------------------------------------------===//
+// Processor itineraries - These values represent the set of all itinerary
+// classes for a given chip set.
+//
+// Set property values to -1 to use the default.
+// See InstrItineraryProps for comments and defaults.
+class ProcessorItineraries<list<FuncUnit> fu, list<Bypass> bp,
+                           list<InstrItinData> iid> {
+  list<FuncUnit> FU = fu;
+  list<Bypass> BP = bp;
+  list<InstrItinData> IID = iid;
+}
+
+// NoItineraries - A marker that can be used by processors without schedule
+// info. Subtargets using NoItineraries can bypass the scheduler's
+// expensive HazardRecognizer because no reservation table is needed.
+def NoItineraries : ProcessorItineraries<[], [], []>;
diff --git a/include/llvm/Target/TargetSchedule.td b/include/llvm/Target/TargetSchedule.td
index caa5a84c83..5bbed58c87 100644
--- a/include/llvm/Target/TargetSchedule.td
+++ b/include/llvm/Target/TargetSchedule.td
@@ -12,141 +12,29 @@
 //
 //===----------------------------------------------------------------------===//
 
-//===----------------------------------------------------------------------===//
-// Processor functional unit - These values represent the function units
-// available across all chip sets for the target.  Eg., IntUnit, FPUnit, ...
-// These may be independent values for each chip set or may be shared across
-// all chip sets of the target.  Each functional unit is treated as a resource
-// during scheduling and has an affect instruction order based on availability
-// during a time interval.
-//
-class FuncUnit;
-
-//===----------------------------------------------------------------------===//
-// Pipeline bypass / forwarding - These values specifies the symbolic names of
-// pipeline bypasses which can be used to forward results of instructions
-// that are forwarded to uses.
-class Bypass;
-def NoBypass : Bypass;
-
-class ReservationKind<bits<1> val> {
-  int Value = val;
-}
-
-def Required : ReservationKind<0>;
-def Reserved : ReservationKind<1>;
-
-//===----------------------------------------------------------------------===//
-// Instruction stage - These values represent a non-pipelined step in
-// the execution of an instruction.  Cycles represents the number of
-// discrete time slots needed to complete the stage.  Units represent
-// the choice of functional units that can be used to complete the
-// stage.  Eg. IntUnit1, IntUnit2. NextCycles indicates how many
-// cycles should elapse from the start of this stage to the start of
-// the next stage in the itinerary.  For example:
-//
-// A stage is specified in one of two ways:
-//
-//   InstrStage<1, [FU_x, FU_y]>     - TimeInc defaults to Cycles
-//   InstrStage<1, [FU_x, FU_y], 0>  - TimeInc explicit
-//
+include "llvm/Target/TargetItinerary.td"
 
-class InstrStage<int cycles, list<FuncUnit> units,
-                 int timeinc = -1,
-                 ReservationKind kind = Required> {
-  int Cycles          = cycles;       // length of stage in machine cycles
-  list<FuncUnit> Units = units;       // choice of functional units
-  int TimeInc         = timeinc;      // cycles till start of next stage
-  int Kind            = kind.Value;   // kind of FU reservation
-}
-
-//===----------------------------------------------------------------------===//
-// Instruction itinerary - An itinerary represents a sequential series of steps
-// required to complete an instruction.  Itineraries are represented as lists of
-// instruction stages.
+// The SchedMachineModel is defined by subtargets for three categories of data:
+// 1) Basic properties for coarse grained instruction cost model.
+// 2) Scheduler Read/Write resources for simple per-opcode cost model.
+// 3) Instruction itineraties for detailed reservation tables.
 //
-
-//===----------------------------------------------------------------------===//
-// Instruction itinerary classes - These values represent 'named' instruction
-// itinerary.  Using named itineraries simplifies managing groups of
-// instructions across chip sets.  An instruction uses the same itinerary class
-// across all chip sets.  Thus a new chip set can be added without modifying
-// instruction information.
-//
-class InstrItinClass;
-def NoItinerary : InstrItinClass;
-
-//===----------------------------------------------------------------------===//
-// Instruction itinerary data - These values provide a runtime map of an
-// instruction itinerary class (name) to its itinerary data.
-//
-// NumMicroOps represents the number of micro-operations that each instruction
-// in the class are decoded to. If the number is zero, then it means the
-// instruction can decode into variable number of micro-ops and it must be
-// determined dynamically. This directly relates to the itineraries
-// global IssueWidth property, which constrains the number of microops
-// that can issue per cycle.
-//
-// OperandCycles are optional "cycle counts". They specify the cycle after
-// instruction issue the values which correspond to specific operand indices
-// are defined or read. Bypasses are optional "pipeline forwarding pathes", if
-// a def by an instruction is available on a specific bypass and the use can
-// read from the same bypass, then the operand use latency is reduced by one.
-//
-//  InstrItinData<IIC_iLoad_i , [InstrStage<1, [A9_Pipe1]>,
-//                               InstrStage<1, [A9_AGU]>],
-//                              [3, 1], [A9_LdBypass]>,
-//  InstrItinData<IIC_iMVNr   , [InstrStage<1, [A9_Pipe0, A9_Pipe1]>],
-//                              [1, 1], [NoBypass, A9_LdBypass]>,
-//
-// In this example, the instruction of IIC_iLoadi reads its input on cycle 1
-// (after issue) and the result of the load is available on cycle 3. The result
-// is available via forwarding path A9_LdBypass. If it's used by the first
-// source operand of instructions of IIC_iMVNr class, then the operand latency
-// is reduced by 1.
-class InstrItinData<InstrItinClass Class, list<InstrStage> stages,
-                    list<int> operandcycles = [],
-                    list<Bypass> bypasses = [], int uops = 1> {
-  InstrItinClass TheClass = Class;
-  int NumMicroOps = uops;
-  list<InstrStage> Stages = stages;
-  list<int> OperandCycles = operandcycles;
-  list<Bypass> Bypasses = bypasses;
-}
-
-//===----------------------------------------------------------------------===//
-// Processor itineraries - These values represent the set of all itinerary
-// classes for a given chip set.
-//
-// Set property values to -1 to use the default.
-// See InstrItineraryProps for comments and defaults.
-class ProcessorItineraries<list<FuncUnit> fu, list<Bypass> bp,
-                           list<InstrItinData> iid> {
+// Default values for basic properties are defined in MCSchedModel. "-1"
+// indicates that the property is not overriden by the target description.
+class SchedMachineModel {
   int IssueWidth = -1; // Max instructions that may be scheduled per cycle.
   int MinLatency = -1; // Determines which instrucions are allowed in a group.
                        // (-1) inorder (0) ooo, (1): inorder +var latencies.
   int LoadLatency = -1; // Cycles for loads to access the cache.
   int HighLatency = -1; // Approximation of cycles for "high latency" ops.
 
-  list<FuncUnit> FU = fu;
-  list<Bypass> BP = bp;
-  list<InstrItinData> IID = iid;
-}
+  ProcessorItineraries Itineraries = NoItineraries;
 
-// NoItineraries - A marker that can be used by processors without schedule
-// info. Subtargets using NoItineraries can bypass the scheduler's
-// expensive HazardRecognizer because no reservation table is needed.
-def NoItineraries : ProcessorItineraries<[], [], []>;
+  bit NoModel = 0; // Special tag to indicate missing machine model.
+}
 
-// Processor itineraries with non-unit issue width. This allows issue
-// width to be explicity specified at the beginning of the itinerary.
-class MultiIssueItineraries<int issuewidth, int minlatency,
-                            int loadlatency, int highlatency,
-                            list<FuncUnit> fu, list<Bypass> bp,
-                            list<InstrItinData> iid>
-  : ProcessorItineraries<fu, bp, iid> {
-  let IssueWidth = issuewidth;
-  let MinLatency = minlatency;
-  let LoadLatency = loadlatency;
-  let HighLatency = highlatency;
+def NoSchedModel : SchedMachineModel {
+  let NoModel = 1;
 }
+
+// TODO: Define classes for processor and scheduler resources.
diff --git a/lib/CodeGen/MachineScheduler.cpp b/lib/CodeGen/MachineScheduler.cpp
index 847bf1e76e..098ec4741f 100644
--- a/lib/CodeGen/MachineScheduler.cpp
+++ b/lib/CodeGen/MachineScheduler.cpp
@@ -403,7 +403,8 @@ public:
 
   /// getIssueWidth - Return the max instructions per scheduling group.
   unsigned getIssueWidth() const {
-    return InstrItins ? InstrItins->Props.IssueWidth : 1;
+    return (InstrItins && InstrItins->SchedModel)
+      ? InstrItins->SchedModel->IssueWidth : 1;
   }
 
   /// getNumMicroOps - Return the number of issue slots required for this MI.
diff --git a/lib/CodeGen/ScoreboardHazardRecognizer.cpp b/lib/CodeGen/ScoreboardHazardRecognizer.cpp
index 7110b7566a..e675366485 100644
--- a/lib/CodeGen/ScoreboardHazardRecognizer.cpp
+++ b/lib/CodeGen/ScoreboardHazardRecognizer.cpp
@@ -72,10 +72,12 @@ ScoreboardHazardRecognizer(const InstrItineraryData *II,
   ReservedScoreboard.reset(ScoreboardDepth);
   RequiredScoreboard.reset(ScoreboardDepth);
 
+  // If MaxLookAhead is not set above, then we are not enabled.
   if (!isEnabled())
     DEBUG(dbgs() << "Disabled scoreboard hazard recognizer\n");
   else {
-    IssueWidth = ItinData->Props.IssueWidth;
+    // A nonempty itinerary must have a SchedModel.
+    IssueWidth = ItinData->SchedModel->IssueWidth;
     DEBUG(dbgs() << "Using scoreboard hazard recognizer: Depth = "
           << ScoreboardDepth << '\n');
   }
diff --git a/lib/CodeGen/SelectionDAG/ResourcePriorityQueue.cpp b/lib/CodeGen/SelectionDAG/ResourcePriorityQueue.cpp
index 01622cb295..c3794d5f78 100644
--- a/lib/CodeGen/SelectionDAG/ResourcePriorityQueue.cpp
+++ b/lib/CodeGen/SelectionDAG/ResourcePriorityQueue.cpp
@@ -318,7 +318,7 @@ void ResourcePriorityQueue::reserveResources(SUnit *SU) {
 
   // If packet is now full, reset the state so in the next cycle
   // we start fresh.
-  if (Packet.size() >= InstrItins->Props.IssueWidth) {
+  if (Packet.size() >= InstrItins->SchedModel->IssueWidth) {
     ResourcesModel->clearResources();
     Packet.clear();
   }
diff --git a/lib/CodeGen/TargetInstrInfoImpl.cpp b/lib/CodeGen/TargetInstrInfoImpl.cpp
index 54be88a8bb..1da5512c91 100644
--- a/lib/CodeGen/TargetInstrInfoImpl.cpp
+++ b/lib/CodeGen/TargetInstrInfoImpl.cpp
@@ -573,9 +573,9 @@ TargetInstrInfoImpl::getNumMicroOps(const InstrItineraryData *ItinData,
 unsigned TargetInstrInfo::defaultDefLatency(const InstrItineraryData *ItinData,
                                             const MachineInstr *DefMI) const {
   if (DefMI->mayLoad())
-    return ItinData->Props.LoadLatency;
+    return ItinData->SchedModel->LoadLatency;
   if (isHighLatencyDef(DefMI->getOpcode()))
-    return ItinData->Props.HighLatency;
+    return ItinData->SchedModel->HighLatency;
   return 1;
 }
 
@@ -629,7 +629,7 @@ static int computeDefOperandLatency(
   if (FindMin) {
     // If MinLatency is valid, call getInstrLatency. This uses Stage latency if
     // it exists before defaulting to MinLatency.
-    if (ItinData->Props.MinLatency >= 0)
+    if (ItinData->SchedModel->MinLatency >= 0)
       return TII->getInstrLatency(ItinData, DefMI);
 
     // If MinLatency is invalid, OperandLatency is interpreted as MinLatency.
diff --git a/lib/MC/MCSubtargetInfo.cpp b/lib/MC/MCSubtargetInfo.cpp
index 318e5a3da2..05c83f760a 100644
--- a/lib/MC/MCSubtargetInfo.cpp
+++ b/lib/MC/MCSubtargetInfo.cpp
@@ -17,11 +17,13 @@
 
 using namespace llvm;
 
+MCSchedModel MCSchedModel::DefaultSchedModel; // For unknown processors.
+
 void
 MCSubtargetInfo::InitMCSubtargetInfo(StringRef TT, StringRef CPU, StringRef FS,
                                      const SubtargetFeatureKV *PF,
                                      const SubtargetFeatureKV *PD,
-                                     const SubtargetInfoKV *PI,
+                                     const SubtargetInfoKV *ProcSched,
                                      const InstrStage *IS,
                                      const unsigned *OC,
                                      const unsigned *FP,
@@ -29,7 +31,7 @@ MCSubtargetInfo::InitMCSubtargetInfo(StringRef TT, StringRef CPU, StringRef FS,
   TargetTriple = TT;
   ProcFeatures = PF;
   ProcDesc = PD;
-  ProcItins = PI;
+  ProcSchedModel = ProcSched;
   Stages = IS;
   OperandCycles = OC;
   ForwardingPaths = FP;
@@ -68,14 +70,14 @@ uint64_t MCSubtargetInfo::ToggleFeature(StringRef FS) {
 }
 
 
-InstrItineraryData
-MCSubtargetInfo::getInstrItineraryForCPU(StringRef CPU) const {
-  assert(ProcItins && "Instruction itineraries information not available!");
+MCSchedModel *
+MCSubtargetInfo::getSchedModelForCPU(StringRef CPU) const {
+  assert(ProcSchedModel && "Processor machine model not available!");
 
 #ifndef NDEBUG
   for (size_t i = 1; i < NumProcs; i++) {
-    assert(strcmp(ProcItins[i - 1].Key, ProcItins[i].Key) < 0 &&
-           "Itineraries table is not sorted");
+    assert(strcmp(ProcSchedModel[i - 1].Key, ProcSchedModel[i].Key) < 0 &&
+           "Processor machine model table is not sorted");
   }
 #endif
 
@@ -83,16 +85,19 @@ MCSubtargetInfo::getInstrItineraryForCPU(StringRef CPU) const {
   SubtargetInfoKV KV;
   KV.Key = CPU.data();
   const SubtargetInfoKV *Found =
-    std::lower_bound(ProcItins, ProcItins+NumProcs, KV);
-  if (Found == ProcItins+NumProcs || StringRef(Found->Key) != CPU) {
+    std::lower_bound(ProcSchedModel, ProcSchedModel+NumProcs, KV);
+  if (Found == ProcSchedModel+NumProcs || StringRef(Found->Key) != CPU) {
     errs() << "'" << CPU
            << "' is not a recognized processor for this target"
            << " (ignoring processor)\n";
-    return InstrItineraryData();
+    return &MCSchedModel::DefaultSchedModel;
   }
+  assert(Found->Value && "Missing processor SchedModel value");
+  return (MCSchedModel *)Found->Value;
+}
 
-  InstrItinerarySubtargetValue *V =
-    (InstrItinerarySubtargetValue *)Found->Value;
-  return InstrItineraryData(V->Props, Stages, OperandCycles, ForwardingPaths,
-                            V->Itineraries);
+InstrItineraryData
+MCSubtargetInfo::getInstrItineraryForCPU(StringRef CPU) const {
+  MCSchedModel *SchedModel = getSchedModelForCPU(CPU);
+  return InstrItineraryData(SchedModel, Stages, OperandCycles, ForwardingPaths);
 }
diff --git a/lib/Target/ARM/ARM.td b/lib/Target/ARM/ARM.td
index d332d20f80..cd3c0e0a41 100644
--- a/lib/Target/ARM/ARM.td
+++ b/lib/Target/ARM/ARM.td
@@ -204,13 +204,13 @@ def : Processor<"arm1156t2f-s",     ARMV6Itineraries, [HasV6T2Ops, FeatureVFP2,
                                                        FeatureDSPThumb2]>;
 
 // V7a Processors.
-def : Processor<"cortex-a8",        CortexA8Itineraries,
+def : ProcessorModel<"cortex-a8",   CortexA8Model,
                                     [ProcA8, HasV7Ops, FeatureNEON, FeatureDB,
                                      FeatureDSPThumb2, FeatureHasRAS]>;
-def : Processor<"cortex-a9",        CortexA9Itineraries,
+def : ProcessorModel<"cortex-a9",   CortexA9Model,
                                     [ProcA9, HasV7Ops, FeatureNEON, FeatureDB,
                                      FeatureDSPThumb2, FeatureHasRAS]>;
-def : Processor<"cortex-a9-mp",     CortexA9Itineraries,
+def : ProcessorModel<"cortex-a9-mp", CortexA9Model,
                                     [ProcA9, HasV7Ops, FeatureNEON, FeatureDB,
                                      FeatureDSPThumb2, FeatureMP,
                                      FeatureHasRAS]>;
diff --git a/lib/Target/ARM/ARMScheduleA8.td b/lib/Target/ARM/ARMScheduleA8.td
index 61de00a208..56197d4e00 100644
--- a/lib/Target/ARM/ARMScheduleA8.td
+++ b/lib/Target/ARM/ARMScheduleA8.td
@@ -22,11 +22,7 @@ def A8_NLSPipe : FuncUnit; // NEON LS pipe
 //
 // Dual issue pipeline represented by A8_Pipe0 | A8_Pipe1
 //
-def CortexA8Itineraries : MultiIssueItineraries<
-  2,  // IssueWidth
-  -1, // MinLatency - OperandCycles are interpreted as MinLatency.
-  2,  // LoadLatency - overriden by OperandCycles.
-  10, // HighLatency - currently unused.
+def CortexA8Itineraries : ProcessorItineraries<
   [A8_Pipe0, A8_Pipe1, A8_LSPipe, A8_NPipe, A8_NLSPipe],
   [], [
   // Two fully-pipelined integer ALU pipelines
@@ -1061,3 +1057,18 @@ def CortexA8Itineraries : MultiIssueItineraries<
                                InstrStage<1, [A8_NPipe], 0>,
                             InstrStage<2, [A8_NLSPipe]>], [4, 1, 2, 2, 3, 3, 1]>
 ]>;
+
+// ===---------------------------------------------------------------------===//
+// This following definitions describe the simple machine model which
+// will replace itineraries.
+
+// Cortex-A8 machine model for scheduling and other instruction cost heuristics.
+def CortexA8Model : SchedMachineModel {
+  let IssueWidth = 2; // 2 micro-ops are dispatched per cycle.
+  let MinLatency = -1; // OperandCycles are interpreted as MinLatency.
+  let LoadLatency = 2; // Optimistic load latency assuming bypass.
+                       // This is overriden by OperandCycles if the
+                       // Itineraries are queried instead.
+
+  let Itineraries = CortexA8Itineraries;
+}
diff --git a/lib/Target/ARM/ARMScheduleA9.td b/lib/Target/ARM/ARMScheduleA9.td
index 1677ba6a98..738974e5f3 100644
--- a/lib/Target/ARM/ARMScheduleA9.td
+++ b/lib/Target/ARM/ARMScheduleA9.td
@@ -11,6 +11,10 @@
 //
 //===----------------------------------------------------------------------===//
 
+// ===---------------------------------------------------------------------===//
+// This section contains legacy support for itineraries. This is
+// required until SD and PostRA schedulers are replaced by MachineScheduler.
+
 //
 // Ad-hoc scheduling information derived from pretty vague "Cortex-A9 Technical
 // Reference Manual".
@@ -31,11 +35,7 @@ def A9_DRegsN  : FuncUnit; // FP register set, NEON side
 // Bypasses
 def A9_LdBypass : Bypass;
 
-def CortexA9Itineraries : MultiIssueItineraries<
-  2, // IssueWidth - FIXME: A9_Issue0, A9_Issue1 are now redundant.
-  0, // MinLatency - FIXME: for misched, remove InstrStage for OOO operations.
-  2, // LoadLatency - optimistic, assumes bypass, overriden by OperandCycles.
-  10, // HighLatency - currently unused.
+def CortexA9Itineraries : ProcessorItineraries<
   [A9_Issue0, A9_Issue1, A9_Branch, A9_ALU0, A9_ALU1, A9_AGU, A9_NPipe, A9_MUX0,
    A9_LSUnit, A9_DRegsVFP, A9_DRegsN],
   [A9_LdBypass], [
@@ -1874,3 +1874,21 @@ def CortexA9Itineraries : MultiIssueItineraries<
                                InstrStage<2, [A9_NPipe]>],
                               [4, 1, 2, 2, 3, 3, 1]>
 ]>;
+
+// ===---------------------------------------------------------------------===//
+// This following definitions describe the simple machine model which
+// will replace itineraries.
+
+// Cortex-A9 machine model for scheduling and other instruction cost heuristics.
+def CortexA9Model : SchedMachineModel {
+  let IssueWidth = 2; // 2 micro-ops are dispatched per cycle.
+  let MinLatency = 0; // Data dependencies are allowed within dispatch groups.
+  let LoadLatency = 2; // Optimistic load latency assuming bypass.
+                       // This is overriden by OperandCycles if the
+                       // Itineraries are queried instead.
+
+  let Itineraries = CortexA9Itineraries;
+}
+
+// TODO: Add Cortex-A9 processor and scheduler resources.
+
diff --git a/lib/Target/Hexagon/Hexagon.td b/lib/Target/Hexagon/Hexagon.td
index 8201de3f2a..451e56206e 100644
--- a/lib/Target/Hexagon/Hexagon.td
+++ b/lib/Target/Hexagon/Hexagon.td
@@ -47,14 +47,14 @@ def HexagonInstrInfo : InstrInfo;
 // Hexagon processors supported.
 //===----------------------------------------------------------------------===//
 
-class Proc<string Name, ProcessorItineraries Itin,
+class Proc<string Name, SchedMachineModel Model,
            list<SubtargetFeature> Features>
- : Processor<Name, Itin, Features>;
+ : ProcessorModel<Name, Model, Features>;
 
-def : Proc<"hexagonv2", HexagonItineraries,   [ArchV2]>;
-def : Proc<"hexagonv3", HexagonItineraries,   [ArchV2, ArchV3]>;
-def : Proc<"hexagonv4", HexagonItinerariesV4, [ArchV2, ArchV3, ArchV4]>;
-def : Proc<"hexagonv5", HexagonItinerariesV4, [ArchV2, ArchV3, ArchV4, ArchV5]>;
+def : Proc<"hexagonv2", HexagonModel,   [ArchV2]>;
+def : Proc<"hexagonv3", HexagonModel,   [ArchV2, ArchV3]>;
+def : Proc<"hexagonv4", HexagonModelV4, [ArchV2, ArchV3, ArchV4]>;
+def : Proc<"hexagonv5", HexagonModelV4, [ArchV2, ArchV3, ArchV4, ArchV5]>;
 
 
 // Hexagon Uses the MC printer for assembler output, so make sure the TableGen
diff --git a/lib/Target/Hexagon/HexagonSchedule.td b/lib/Target/Hexagon/HexagonSchedule.td
index b4df6784e7..d1076b8e44 100644
--- a/lib/Target/Hexagon/HexagonSchedule.td
+++ b/lib/Target/Hexagon/HexagonSchedule.td
@@ -41,9 +41,12 @@ def HexagonItineraries :
         InstrItinData<SYS    , [InstrStage<1, [LSUNIT]>]>,
         InstrItinData<MARKER , [InstrStage<1, [LUNIT, LSUNIT, MUNIT, SUNIT]>]>,
         InstrItinData<PSEUDO , [InstrStage<1, [LUNIT, LSUNIT, MUNIT, SUNIT]>]>
-      ]> {
+      ]>;
+
+def HexagonModel : SchedMachineModel {
   // Max issue per cycle == bundle width.
   let IssueWidth = 4;
+  let Itineraries = HexagonItineraries;
 }
 
 //===----------------------------------------------------------------------===//
diff --git a/lib/Target/Hexagon/HexagonScheduleV4.td b/lib/Target/Hexagon/HexagonScheduleV4.td
index 8d6f7b2b7a..9b41126ca6 100644
--- a/lib/Target/Hexagon/HexagonScheduleV4.td
+++ b/lib/Target/Hexagon/HexagonScheduleV4.td
@@ -52,12 +52,14 @@ def HexagonItinerariesV4 :
         InstrItinData<MARKER , [InstrStage<1, [SLOT0, SLOT1, SLOT2, SLOT3]>]>,
         InstrItinData<PREFIX , [InstrStage<1, [SLOT0, SLOT1, SLOT2, SLOT3]>]>,
         InstrItinData<PSEUDO , [InstrStage<1, [SLOT0, SLOT1, SLOT2, SLOT3]>]>
-      ]> {
+      ]>;
+
+def HexagonModelV4 : SchedMachineModel {
   // Max issue per cycle == bundle width.
   let IssueWidth = 4;
+  let Itineraries = HexagonItinerariesV4;
 }
 
-
 //===----------------------------------------------------------------------===//
 // Hexagon V4 Resource Definitions -
 //===----------------------------------------------------------------------===//
diff --git a/lib/Target/X86/X86.td b/lib/Target/X86/X86.td
index 0aafd60548..6c1a816c9f 100644
--- a/lib/Target/X86/X86.td
+++ b/lib/Target/X86/X86.td
@@ -131,10 +131,10 @@ def ProcIntelAtom : SubtargetFeature<"atom", "X86ProcFamily", "IntelAtom",
                     "Intel Atom processors">;
 
 class Proc<string Name, list<SubtargetFeature> Features>
- : Processor<Name, GenericItineraries, Features>;
+ : ProcessorModel<Name, GenericModel, Features>;
 
 class AtomProc<string Name, list<SubtargetFeature> Features>
- : Processor<Name, AtomItineraries, Features>;
+ : ProcessorModel<Name, AtomModel, Features>;
 
 def : Proc<"generic",         []>;
 def : Proc<"i386",            []>;
diff --git a/lib/Target/X86/X86Schedule.td b/lib/Target/X86/X86Schedule.td
index 4331cf31e8..c14407f9ac 100644
--- a/lib/Target/X86/X86Schedule.td
+++ b/lib/Target/X86/X86Schedule.td
@@ -470,14 +470,12 @@ def IIC_NOP : InstrItinClass;
 // latencies. Since these latencies are not used for pipeline hazards,
 // they do not need to be exact.
 //
-// This set of instruction itineraries should contain no reference to
-// InstrStages. When an iterary has no stages, the scheduler can
-// bypass the logic needed for checking pipeline stage hazards.
-def GenericItineraries : MultiIssueItineraries<
-  4, // IssueWidth
-  0, // MinLatency
-  4, // LoadLatency (expected, may be overriden by OperandCycles)
- 10, // HighLatency (expected, may be overriden by OperandCycles)
- [], [], []>; // no FuncUnits, Bypasses, or InstrItinData.
+// The GenericModel contains no instruciton itineraries.
+def GenericModel : SchedMachineModel {
+  let IssueWidth = 4;
+  let MinLatency = 0;
+  let LoadLatency = 4;
+  let HighLatency = 10;
+}
 
 include "X86ScheduleAtom.td"
diff --git a/lib/Target/X86/X86ScheduleAtom.td b/lib/Target/X86/X86ScheduleAtom.td
index 56dd3407b2..87102614cc 100644
--- a/lib/Target/X86/X86ScheduleAtom.td
+++ b/lib/Target/X86/X86ScheduleAtom.td
@@ -22,12 +22,7 @@ def Port0 : FuncUnit; // ALU: ALU0, shift/rotate, load/store
 def Port1 : FuncUnit; // ALU: ALU1, bit processing, jump, and LEA
                       // SIMD/FP: SIMD ALU, FP Adder
 
-def AtomItineraries : MultiIssueItineraries<
-  2, // IssueWidth=2 allows 2 instructions per scheduling group.
-  1, // MinLatency=1. InstrStage cycles overrides MinLatency.
-     //               OperandCycles may be used for expected latency.
-  3, // LoadLatency (expected, may be overriden by OperandCycles)
-  30,// HighLatency (expected, may be overriden by OperandCycles)
+def AtomItineraries : ProcessorItineraries<
   [ Port0, Port1 ],
   [], [
   // P0 only
@@ -523,3 +518,13 @@ def AtomItineraries : MultiIssueItineraries<
   InstrItinData<IIC_NOP, [InstrStage<1, [Port0, Port1]>] >
   ]>;
 
+// Atom machine model.
+def AtomModel : SchedMachineModel {
+  let IssueWidth = 2;  // Allows 2 instructions per scheduling group.
+  let MinLatency = 1;  // InstrStage cycles overrides MinLatency.
+                       // OperandCycles may be used for expected latency.
+  let LoadLatency = 3; // Expected cycles, may be overriden by OperandCycles.
+  let HighLatency = 30;// Expected, may be overriden by OperandCycles.
+
+  let Itineraries = AtomItineraries;
+}
diff --git a/utils/TableGen/CMakeLists.txt b/utils/TableGen/CMakeLists.txt
index c5585f5eaa..0e14cbae38 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 0000000000..f57fd182ea
--- /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 0000000000..9da0145732
--- /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 4bc4c54f8b..1dd2efc4a1 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 85463da597..2f8cee4588 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 600586ff4a..3adb8694d9 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 1c37d15fe8..48dbdc2c7c 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