//===----------------------------------------------------------------------===//
//
// This file implements the ScheduleDAG class, which is used as the common
-// base class for instruction schedulers.
+// base class for instruction schedulers. This encapsulates the scheduling DAG,
+// which is shared between SelectionDAG and MachineInstr scheduling.
//
//===----------------------------------------------------------------------===//
#define LLVM_CODEGEN_SCHEDULEDAG_H
#include "llvm/CodeGen/MachineBasicBlock.h"
-#include "llvm/Target/TargetMachine.h"
+#include "llvm/Target/TargetLowering.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/BitVector.h"
#include "llvm/ADT/GraphTraits.h"
class ScheduleDAG;
class SDNode;
class TargetInstrInfo;
- class TargetInstrDesc;
+ class MCInstrDesc;
class TargetMachine;
class TargetRegisterClass;
template<class Graph> class GraphWriter;
/// the value of the Latency field of the predecessor, however advanced
/// models may provide additional information about specific edges.
unsigned Latency;
+ /// Record MinLatency seperately from "expected" Latency.
+ unsigned MinLatency;
public:
/// SDep - Construct a null SDep. This is only for use by container
SDep(SUnit *S, Kind kind, unsigned latency = 1, unsigned Reg = 0,
bool isNormalMemory = false, bool isMustAlias = false,
bool isArtificial = false)
- : Dep(S, kind), Contents(), Latency(latency) {
+ : Dep(S, kind), Contents(), Latency(latency), MinLatency(latency) {
switch (kind) {
case Anti:
case Output:
}
}
- bool operator==(const SDep &Other) const {
- if (Dep != Other.Dep || Latency != Other.Latency) return false;
+ /// Return true if the specified SDep is equivalent except for latency.
+ bool overlaps(const SDep &Other) const {
+ if (Dep != Other.Dep) return false;
switch (Dep.getInt()) {
case Data:
case Anti:
Contents.Order.isMustAlias == Other.Contents.Order.isMustAlias &&
Contents.Order.isArtificial == Other.Contents.Order.isArtificial;
}
- assert(0 && "Invalid dependency kind!");
- return false;
+ llvm_unreachable("Invalid dependency kind!");
+ }
+
+ bool operator==(const SDep &Other) const {
+ return overlaps(Other)
+ && Latency == Other.Latency && MinLatency == Other.MinLatency;
}
bool operator!=(const SDep &Other) const {
Latency = Lat;
}
+ /// getMinLatency - Return the minimum latency for this edge. Minimum
+ /// latency is used for scheduling groups, while normal (expected) latency
+ /// is for instruction cost and critical path.
+ unsigned getMinLatency() const {
+ return MinLatency;
+ }
+
+ /// setMinLatency - Set the minimum latency for this edge.
+ void setMinLatency(unsigned Lat) {
+ MinLatency = Lat;
+ }
+
//// getSUnit - Return the SUnit to which this edge points.
SUnit *getSUnit() const {
return Dep.getPointer();
}
};
+ template <>
+ struct isPodLike<SDep> { static const bool value = true; };
+
/// SUnit - Scheduling unit. This is a node in the scheduling DAG.
class SUnit {
private:
public:
SUnit *OrigNode; // If not this, the node from which
// this node was cloned.
-
- // Preds/Succs - The SUnits before/after us in the graph. The boolean value
- // is true if the edge is a token chain edge, false if it is a value edge.
+ // (SD scheduling only)
+
+ // Preds/Succs - The SUnits before/after us in the graph.
SmallVector<SDep, 4> Preds; // All sunit predecessors.
SmallVector<SDep, 4> Succs; // All sunit successors.
unsigned NodeNum; // Entry # of node in the node vector.
unsigned NodeQueueId; // Queue id of node.
- unsigned short Latency; // Node latency.
unsigned NumPreds; // # of SDep::Data preds.
unsigned NumSuccs; // # of SDep::Data sucss.
unsigned NumPredsLeft; // # of preds not scheduled.
unsigned NumSuccsLeft; // # of succs not scheduled.
+ unsigned short NumRegDefsLeft; // # of reg defs with no scheduled use.
+ unsigned short Latency; // Node latency.
+ bool isVRegCycle : 1; // May use and def the same vreg.
+ bool isCall : 1; // Is a function call.
+ bool isCallOp : 1; // Is a function call operand.
bool isTwoAddress : 1; // Is a two-address instruction.
bool isCommutable : 1; // Is a commutable instruction.
bool hasPhysRegDefs : 1; // Has physreg defs that are being used.
bool isAvailable : 1; // True once available.
bool isScheduled : 1; // True once scheduled.
bool isScheduleHigh : 1; // True if preferable to schedule high.
+ bool isScheduleLow : 1; // True if preferable to schedule low.
bool isCloned : 1; // True if this node has been cloned.
Sched::Preference SchedulingPref; // Scheduling preference.
- SmallVector<MachineInstr*, 4> DbgInstrList; // dbg_values referencing this.
private:
bool isDepthCurrent : 1; // True if Depth is current.
bool isHeightCurrent : 1; // True if Height is current.
unsigned Depth; // Node depth.
unsigned Height; // Node height.
public:
+ unsigned TopReadyCycle; // Cycle relative to start when node is ready.
+ unsigned BotReadyCycle; // Cycle relative to end when node is ready.
+
const TargetRegisterClass *CopyDstRC; // Is a special copy node if not null.
const TargetRegisterClass *CopySrcRC;
-
+
/// SUnit - Construct an SUnit for pre-regalloc scheduling to represent
/// an SDNode and any nodes flagged to it.
SUnit(SDNode *node, unsigned nodenum)
: Node(node), Instr(0), OrigNode(0), NodeNum(nodenum),
- NodeQueueId(0), Latency(0), NumPreds(0), NumSuccs(0), NumPredsLeft(0),
- NumSuccsLeft(0), isTwoAddress(false), isCommutable(false),
- hasPhysRegDefs(false), hasPhysRegClobbers(false),
+ NodeQueueId(0), NumPreds(0), NumSuccs(0), NumPredsLeft(0),
+ NumSuccsLeft(0), NumRegDefsLeft(0), Latency(0),
+ isVRegCycle(false), isCall(false), isCallOp(false), isTwoAddress(false),
+ isCommutable(false), hasPhysRegDefs(false), hasPhysRegClobbers(false),
isPending(false), isAvailable(false), isScheduled(false),
- isScheduleHigh(false), isCloned(false),
+ isScheduleHigh(false), isScheduleLow(false), isCloned(false),
SchedulingPref(Sched::None),
isDepthCurrent(false), isHeightCurrent(false), Depth(0), Height(0),
- CopyDstRC(NULL), CopySrcRC(NULL) {}
+ TopReadyCycle(0), BotReadyCycle(0), CopyDstRC(NULL), CopySrcRC(NULL) {}
/// SUnit - Construct an SUnit for post-regalloc scheduling to represent
/// a MachineInstr.
SUnit(MachineInstr *instr, unsigned nodenum)
: Node(0), Instr(instr), OrigNode(0), NodeNum(nodenum),
- NodeQueueId(0), Latency(0), NumPreds(0), NumSuccs(0), NumPredsLeft(0),
- NumSuccsLeft(0), isTwoAddress(false), isCommutable(false),
- hasPhysRegDefs(false), hasPhysRegClobbers(false),
+ NodeQueueId(0), NumPreds(0), NumSuccs(0), NumPredsLeft(0),
+ NumSuccsLeft(0), NumRegDefsLeft(0), Latency(0),
+ isVRegCycle(false), isCall(false), isCallOp(false), isTwoAddress(false),
+ isCommutable(false), hasPhysRegDefs(false), hasPhysRegClobbers(false),
isPending(false), isAvailable(false), isScheduled(false),
- isScheduleHigh(false), isCloned(false),
+ isScheduleHigh(false), isScheduleLow(false), isCloned(false),
SchedulingPref(Sched::None),
isDepthCurrent(false), isHeightCurrent(false), Depth(0), Height(0),
- CopyDstRC(NULL), CopySrcRC(NULL) {}
+ TopReadyCycle(0), BotReadyCycle(0), CopyDstRC(NULL), CopySrcRC(NULL) {}
/// SUnit - Construct a placeholder SUnit.
SUnit()
: Node(0), Instr(0), OrigNode(0), NodeNum(~0u),
- NodeQueueId(0), Latency(0), NumPreds(0), NumSuccs(0), NumPredsLeft(0),
- NumSuccsLeft(0), isTwoAddress(false), isCommutable(false),
- hasPhysRegDefs(false), hasPhysRegClobbers(false),
+ NodeQueueId(0), NumPreds(0), NumSuccs(0), NumPredsLeft(0),
+ NumSuccsLeft(0), NumRegDefsLeft(0), Latency(0),
+ isVRegCycle(false), isCall(false), isCallOp(false), isTwoAddress(false),
+ isCommutable(false), hasPhysRegDefs(false), hasPhysRegClobbers(false),
isPending(false), isAvailable(false), isScheduled(false),
- isScheduleHigh(false), isCloned(false),
+ isScheduleHigh(false), isScheduleLow(false), isCloned(false),
SchedulingPref(Sched::None),
isDepthCurrent(false), isHeightCurrent(false), Depth(0), Height(0),
- CopyDstRC(NULL), CopySrcRC(NULL) {}
+ TopReadyCycle(0), BotReadyCycle(0), CopyDstRC(NULL), CopySrcRC(NULL) {}
/// setNode - Assign the representative SDNode for this SUnit.
/// This may be used during pre-regalloc scheduling.
return Node;
}
+ /// isInstr - Return true if this SUnit refers to a machine instruction as
+ /// opposed to an SDNode.
+ bool isInstr() const { return Instr; }
+
/// setInstr - Assign the instruction for the SUnit.
/// This may be used during post-regalloc scheduling.
void setInstr(MachineInstr *MI) {
/// addPred - This adds the specified edge as a pred of the current node if
/// not already. It also adds the current node as a successor of the
/// specified node.
- void addPred(const SDep &D);
+ bool addPred(const SDep &D);
/// removePred - This removes the specified edge as a pred of the current
/// node if it exists. It also removes the current node as a successor of
void removePred(const SDep &D);
/// getDepth - Return the depth of this node, which is the length of the
- /// maximum path up to any node with has no predecessors.
+ /// maximum path up to any node which has no predecessors.
unsigned getDepth() const {
- if (!isDepthCurrent)
+ if (!isDepthCurrent)
const_cast<SUnit *>(this)->ComputeDepth();
return Depth;
}
/// getHeight - Return the height of this node, which is the length of the
- /// maximum path down to any node with has no successors.
+ /// maximum path down to any node which has no successors.
unsigned getHeight() const {
- if (!isHeightCurrent)
+ if (!isHeightCurrent)
const_cast<SUnit *>(this)->ComputeHeight();
return Height;
}
return true;
return false;
}
-
+
/// isSucc - Test if node N is a successor of this node.
bool isSucc(SUnit *N) {
for (unsigned i = 0, e = (unsigned)Succs.size(); i != e; ++i)
return false;
}
+ bool isTopReady() const {
+ return NumPredsLeft == 0;
+ }
+ bool isBottomReady() const {
+ return NumSuccsLeft == 0;
+ }
+
void dump(const ScheduleDAG *G) const;
void dumpAll(const ScheduleDAG *G) const;
void print(raw_ostream &O, const ScheduleDAG *G) const;
//===--------------------------------------------------------------------===//
/// SchedulingPriorityQueue - This interface is used to plug different
/// priorities computation algorithms into the list scheduler. It implements
- /// the interface of a standard priority queue, where nodes are inserted in
+ /// the interface of a standard priority queue, where nodes are inserted in
/// arbitrary order and returned in priority order. The computation of the
/// priority and the representation of the queue are totally up to the
/// implementation to decide.
- ///
+ ///
class SchedulingPriorityQueue {
+ virtual void anchor();
unsigned CurCycle;
+ bool HasReadyFilter;
public:
- SchedulingPriorityQueue() : CurCycle(0) {}
+ SchedulingPriorityQueue(bool rf = false):
+ CurCycle(0), HasReadyFilter(rf) {}
virtual ~SchedulingPriorityQueue() {}
-
+
+ virtual bool isBottomUp() const = 0;
+
virtual void initNodes(std::vector<SUnit> &SUnits) = 0;
virtual void addNode(const SUnit *SU) = 0;
virtual void updateNode(const SUnit *SU) = 0;
virtual void releaseState() = 0;
virtual bool empty() const = 0;
+
+ bool hasReadyFilter() const { return HasReadyFilter; }
+
+ virtual bool tracksRegPressure() const { return false; }
+
+ virtual bool isReady(SUnit *) const {
+ assert(!HasReadyFilter && "The ready filter must override isReady()");
+ return true;
+ }
virtual void push(SUnit *U) = 0;
-
- virtual void push_all(const std::vector<SUnit *> &Nodes) = 0;
+
+ void push_all(const std::vector<SUnit *> &Nodes) {
+ for (std::vector<SUnit *>::const_iterator I = Nodes.begin(),
+ E = Nodes.end(); I != E; ++I)
+ push(*I);
+ }
+
virtual SUnit *pop() = 0;
virtual void remove(SUnit *SU) = 0;
- /// ScheduledNode - As each node is scheduled, this method is invoked. This
+ virtual void dump(ScheduleDAG *) const {}
+
+ /// scheduledNode - As each node is scheduled, this method is invoked. This
/// allows the priority function to adjust the priority of related
/// unscheduled nodes, for example.
///
- virtual void ScheduledNode(SUnit *) {}
+ virtual void scheduledNode(SUnit *) {}
- virtual void UnscheduledNode(SUnit *) {}
+ virtual void unscheduledNode(SUnit *) {}
void setCurCycle(unsigned Cycle) {
CurCycle = Cycle;
unsigned getCurCycle() const {
return CurCycle;
- }
+ }
};
class ScheduleDAG {
public:
- MachineBasicBlock *BB; // The block in which to insert instructions
- MachineBasicBlock::iterator InsertPos;// The position to insert instructions
const TargetMachine &TM; // Target processor
const TargetInstrInfo *TII; // Target instruction information
const TargetRegisterInfo *TRI; // Target processor register info
MachineFunction &MF; // Machine function
MachineRegisterInfo &MRI; // Virtual/real register map
- std::vector<SUnit*> Sequence; // The schedule. Null SUnit*'s
- // represent noop instructions.
std::vector<SUnit> SUnits; // The scheduling units.
SUnit EntrySU; // Special node for the region entry.
SUnit ExitSU; // Special node for the region exit.
+#ifdef NDEBUG
+ static const bool StressSched = false;
+#else
+ bool StressSched;
+#endif
+
explicit ScheduleDAG(MachineFunction &mf);
virtual ~ScheduleDAG();
+ /// clearDAG - clear the DAG state (between regions).
+ void clearDAG();
+
+ /// getInstrDesc - Return the MCInstrDesc of this SUnit.
+ /// Return NULL for SDNodes without a machine opcode.
+ const MCInstrDesc *getInstrDesc(const SUnit *SU) const {
+ if (SU->isInstr()) return &SU->getInstr()->getDesc();
+ return getNodeDesc(SU->getNode());
+ }
+
/// viewGraph - Pop up a GraphViz/gv window with the ScheduleDAG rendered
/// using 'dot'.
///
+ void viewGraph(const Twine &Name, const Twine &Title);
void viewGraph();
-
- /// EmitSchedule - Insert MachineInstrs into the MachineBasicBlock
- /// according to the order specified in Sequence.
- ///
- virtual MachineBasicBlock *EmitSchedule() = 0;
-
- void dumpSchedule() const;
virtual void dumpNode(const SUnit *SU) const = 0;
/// of the ScheduleDAG.
virtual std::string getGraphNodeLabel(const SUnit *SU) const = 0;
+ /// getDAGLabel - Return a label for the region of code covered by the DAG.
+ virtual std::string getDAGName() const = 0;
+
/// addCustomGraphFeatures - Add custom features for a visualization of
/// the ScheduleDAG.
virtual void addCustomGraphFeatures(GraphWriter<ScheduleDAG*> &) const {}
#ifndef NDEBUG
- /// VerifySchedule - Verify that all SUnits were scheduled and that
- /// their state is consistent.
- void VerifySchedule(bool isBottomUp);
+ /// VerifyScheduledDAG - Verify that all SUnits were scheduled and that
+ /// their state is consistent. Return the number of scheduled SUnits.
+ unsigned VerifyScheduledDAG(bool isBottomUp);
#endif
protected:
- /// Run - perform scheduling.
- ///
- void Run(MachineBasicBlock *bb, MachineBasicBlock::iterator insertPos);
-
- /// BuildSchedGraph - Build SUnits and set up their Preds and Succs
- /// to form the scheduling dependency graph.
- ///
- virtual void BuildSchedGraph(AliasAnalysis *AA) = 0;
-
/// ComputeLatency - Compute node latency.
///
- virtual void ComputeLatency(SUnit *SU) = 0;
-
- /// ComputeOperandLatency - Override dependence edge latency using
- /// operand use/def information
- ///
- virtual void ComputeOperandLatency(SUnit *, SUnit *,
- SDep&) const { }
-
- /// Schedule - Order nodes according to selected style, filling
- /// in the Sequence member.
- ///
- virtual void Schedule() = 0;
+ virtual void computeLatency(SUnit *SU) = 0;
/// ForceUnitLatencies - Return true if all scheduling edges should be given
/// a latency value of one. The default is to return false; schedulers may
/// override this as needed.
- virtual bool ForceUnitLatencies() const { return false; }
+ virtual bool forceUnitLatencies() const { return false; }
- /// EmitNoop - Emit a noop instruction.
- ///
- void EmitNoop();
-
- void EmitPhysRegCopy(SUnit *SU, DenseMap<SUnit*, unsigned> &VRBaseMap);
+ private:
+ // Return the MCInstrDesc of this SDNode or NULL.
+ const MCInstrDesc *getNodeDesc(const SDNode *Node) const;
};
class SUnitIterator : public std::iterator<std::forward_iterator_tag,
/// Visited - a set of nodes visited during a DFS traversal.
BitVector Visited;
- /// DFS - make a DFS traversal and mark all nodes affected by the
+ /// DFS - make a DFS traversal and mark all nodes affected by the
/// edge insertion. These nodes will later get new topological indexes
/// by means of the Shift method.
void DFS(const SUnit *SU, int UpperBound, bool& HasLoop);
public:
explicit ScheduleDAGTopologicalSort(std::vector<SUnit> &SUnits);
- /// InitDAGTopologicalSorting - create the initial topological
+ /// InitDAGTopologicalSorting - create the initial topological
/// ordering from the DAG to be scheduled.
void InitDAGTopologicalSorting();
/// will create a cycle.
bool WillCreateCycle(SUnit *SU, SUnit *TargetSU);
- /// AddPred - Updates the topological ordering to accomodate an edge
+ /// AddPred - Updates the topological ordering to accommodate an edge
/// to be added from SUnit X to SUnit Y.
void AddPred(SUnit *Y, SUnit *X);
- /// RemovePred - Updates the topological ordering to accomodate an
+ /// RemovePred - Updates the topological ordering to accommodate an
/// an edge to be removed from the specified node N from the predecessors
/// of the current node M.
void RemovePred(SUnit *M, SUnit *N);