X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=include%2Fllvm%2FCodeGen%2FScheduleDAG.h;h=371ac6c34d08999f205ea9d5fde2bd43fadff75e;hb=2c46deb1d07f4588ee70059cdd4c7145f81bc8e8;hp=71f0e88ed1a8c0bb328b2ae98a61d4dc40354d4f;hpb=d59b083d22a01d9c48c9ea16757186ebf7c7049a;p=oota-llvm.git diff --git a/include/llvm/CodeGen/ScheduleDAG.h b/include/llvm/CodeGen/ScheduleDAG.h index 71f0e88ed1a..371ac6c34d0 100644 --- a/include/llvm/CodeGen/ScheduleDAG.h +++ b/include/llvm/CodeGen/ScheduleDAG.h @@ -8,110 +8,353 @@ //===----------------------------------------------------------------------===// // // 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. // //===----------------------------------------------------------------------===// #ifndef LLVM_CODEGEN_SCHEDULEDAG_H #define LLVM_CODEGEN_SCHEDULEDAG_H -#include "llvm/CodeGen/MachineBasicBlock.h" -#include "llvm/ADT/DenseMap.h" +#include "llvm/ADT/BitVector.h" #include "llvm/ADT/GraphTraits.h" +#include "llvm/ADT/PointerIntPair.h" #include "llvm/ADT/SmallVector.h" +#include "llvm/CodeGen/MachineInstr.h" +#include "llvm/Target/TargetLowering.h" namespace llvm { - struct SUnit; + class AliasAnalysis; + class SUnit; class MachineConstantPool; class MachineFunction; - class MachineModuleInfo; class MachineRegisterInfo; class MachineInstr; + struct MCSchedClassDesc; class TargetRegisterInfo; class ScheduleDAG; - class SelectionDAG; class SDNode; class TargetInstrInfo; - class TargetInstrDesc; - class TargetLowering; + class MCInstrDesc; class TargetMachine; class TargetRegisterClass; template class GraphWriter; - /// SDep - Scheduling dependency. It keeps track of dependent nodes, - /// cost of the depdenency, etc. - struct SDep { - SUnit *Dep; // Dependent - either a predecessor or a successor. - unsigned Reg; // If non-zero, this dep is a physreg dependency. - int Cost; // Cost of the dependency. - bool isCtrl : 1; // True iff it's a control dependency. - bool isArtificial : 1; // True iff it's an artificial ctrl dep added - // during sched that may be safely deleted if - // necessary. - bool isAntiDep : 1; // True iff it's an anti-dependency (on a physical - // register. - SDep(SUnit *d, unsigned r, int t, bool c, bool a, bool anti) - : Dep(d), Reg(r), Cost(t), isCtrl(c), isArtificial(a), isAntiDep(anti) {} + /// SDep - Scheduling dependency. This represents one direction of an + /// edge in the scheduling DAG. + class SDep { + public: + /// Kind - These are the different kinds of scheduling dependencies. + enum Kind { + Data, ///< Regular data dependence (aka true-dependence). + Anti, ///< A register anti-dependedence (aka WAR). + Output, ///< A register output-dependence (aka WAW). + Order ///< Any other ordering dependency. + }; + + // Strong dependencies must be respected by the scheduler. Artificial + // dependencies may be removed only if they are redundant with another + // strong depedence. + // + // Weak dependencies may be violated by the scheduling strategy, but only if + // the strategy can prove it is correct to do so. + // + // Strong OrderKinds must occur before "Weak". + // Weak OrderKinds must occur after "Weak". + enum OrderKind { + Barrier, ///< An unknown scheduling barrier. + MayAliasMem, ///< Nonvolatile load/Store instructions that may alias. + MustAliasMem, ///< Nonvolatile load/Store instructions that must alias. + Artificial, ///< Arbitrary strong DAG edge (no real dependence). + Weak, ///< Arbitrary weak DAG edge. + Cluster ///< Weak DAG edge linking a chain of clustered instrs. + }; + + private: + /// Dep - A pointer to the depending/depended-on SUnit, and an enum + /// indicating the kind of the dependency. + PointerIntPair Dep; + + /// Contents - A union discriminated by the dependence kind. + union { + /// Reg - For Data, Anti, and Output dependencies, the associated + /// register. For Data dependencies that don't currently have a register + /// assigned, this is set to zero. + unsigned Reg; + + /// Order - Additional information about Order dependencies. + unsigned OrdKind; // enum OrderKind + } Contents; + + /// Latency - The time associated with this edge. Often this is just + /// the value of the Latency field of the predecessor, however advanced + /// models may provide additional information about specific edges. + unsigned Latency; + + public: + /// SDep - Construct a null SDep. This is only for use by container + /// classes which require default constructors. SUnits may not + /// have null SDep edges. + SDep() : Dep(0, Data) {} + + /// SDep - Construct an SDep with the specified values. + SDep(SUnit *S, Kind kind, unsigned Reg) + : Dep(S, kind), Contents() { + switch (kind) { + default: + llvm_unreachable("Reg given for non-register dependence!"); + case Anti: + case Output: + assert(Reg != 0 && + "SDep::Anti and SDep::Output must use a non-zero Reg!"); + Contents.Reg = Reg; + Latency = 0; + break; + case Data: + Contents.Reg = Reg; + Latency = 1; + break; + } + } + SDep(SUnit *S, OrderKind kind) + : Dep(S, Order), Contents(), Latency(0) { + Contents.OrdKind = kind; + } + + /// 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: + case Output: + return Contents.Reg == Other.Contents.Reg; + case Order: + return Contents.OrdKind == Other.Contents.OrdKind; + } + llvm_unreachable("Invalid dependency kind!"); + } + + bool operator==(const SDep &Other) const { + return overlaps(Other) && Latency == Other.Latency; + } + + bool operator!=(const SDep &Other) const { + return !operator==(Other); + } + + /// getLatency - Return the latency value for this edge, which roughly + /// means the minimum number of cycles that must elapse between the + /// predecessor and the successor, given that they have this edge + /// between them. + unsigned getLatency() const { + return Latency; + } + + /// setLatency - Set the latency for this edge. + void setLatency(unsigned Lat) { + Latency = Lat; + } + + //// getSUnit - Return the SUnit to which this edge points. + SUnit *getSUnit() const { + return Dep.getPointer(); + } + + //// setSUnit - Assign the SUnit to which this edge points. + void setSUnit(SUnit *SU) { + Dep.setPointer(SU); + } + + /// getKind - Return an enum value representing the kind of the dependence. + Kind getKind() const { + return Dep.getInt(); + } + + /// isCtrl - Shorthand for getKind() != SDep::Data. + bool isCtrl() const { + return getKind() != Data; + } + + /// isNormalMemory - Test if this is an Order dependence between two + /// memory accesses where both sides of the dependence access memory + /// in non-volatile and fully modeled ways. + bool isNormalMemory() const { + return getKind() == Order && (Contents.OrdKind == MayAliasMem + || Contents.OrdKind == MustAliasMem); + } + + /// isMustAlias - Test if this is an Order dependence that is marked + /// as "must alias", meaning that the SUnits at either end of the edge + /// have a memory dependence on a known memory location. + bool isMustAlias() const { + return getKind() == Order && Contents.OrdKind == MustAliasMem; + } + + /// isWeak - Test if this a weak dependence. Weak dependencies are + /// considered DAG edges for height computation and other heuristics, but do + /// not force ordering. Breaking a weak edge may require the scheduler to + /// compensate, for example by inserting a copy. + bool isWeak() const { + return getKind() == Order && Contents.OrdKind >= Weak; + } + + /// isArtificial - Test if this is an Order dependence that is marked + /// as "artificial", meaning it isn't necessary for correctness. + bool isArtificial() const { + return getKind() == Order && Contents.OrdKind == Artificial; + } + + /// isCluster - Test if this is an Order dependence that is marked + /// as "cluster", meaning it is artificial and wants to be adjacent. + bool isCluster() const { + return getKind() == Order && Contents.OrdKind == Cluster; + } + + /// isAssignedRegDep - Test if this is a Data dependence that is + /// associated with a register. + bool isAssignedRegDep() const { + return getKind() == Data && Contents.Reg != 0; + } + + /// getReg - Return the register associated with this edge. This is + /// only valid on Data, Anti, and Output edges. On Data edges, this + /// value may be zero, meaning there is no associated register. + unsigned getReg() const { + assert((getKind() == Data || getKind() == Anti || getKind() == Output) && + "getReg called on non-register dependence edge!"); + return Contents.Reg; + } + + /// setReg - Assign the associated register for this edge. This is + /// only valid on Data, Anti, and Output edges. On Anti and Output + /// edges, this value must not be zero. On Data edges, the value may + /// be zero, which would mean that no specific register is associated + /// with this edge. + void setReg(unsigned Reg) { + assert((getKind() == Data || getKind() == Anti || getKind() == Output) && + "setReg called on non-register dependence edge!"); + assert((getKind() != Anti || Reg != 0) && + "SDep::Anti edge cannot use the zero register!"); + assert((getKind() != Output || Reg != 0) && + "SDep::Output edge cannot use the zero register!"); + Contents.Reg = Reg; + } }; + template <> + struct isPodLike { static const bool value = true; }; + /// SUnit - Scheduling unit. This is a node in the scheduling DAG. - struct SUnit { + class SUnit { private: + enum { BoundaryID = ~0u }; + SDNode *Node; // Representative node. MachineInstr *Instr; // Alternatively, a MachineInstr. 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) + + const MCSchedClassDesc *SchedClass; // NULL or resolved SchedClass. + + // Preds/Succs - The SUnits before/after us in the graph. SmallVector Preds; // All sunit predecessors. SmallVector Succs; // All sunit successors. - typedef SmallVector::iterator pred_iterator; - typedef SmallVector::iterator succ_iterator; - typedef SmallVector::const_iterator const_pred_iterator; - typedef SmallVector::const_iterator const_succ_iterator; - + typedef SmallVectorImpl::iterator pred_iterator; + typedef SmallVectorImpl::iterator succ_iterator; + typedef SmallVectorImpl::const_iterator const_pred_iterator; + typedef SmallVectorImpl::const_iterator const_succ_iterator; + unsigned NodeNum; // Entry # of node in the node vector. unsigned NodeQueueId; // Queue id of node. + 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 WeakPredsLeft; // # of weak preds not scheduled. + unsigned WeakSuccsLeft; // # of weak succs not scheduled. + unsigned short NumRegDefsLeft; // # of reg defs with no scheduled use. unsigned short Latency; // Node latency. - short NumPreds; // # of non-control preds. - short NumSuccs; // # of non-control sucss. - short NumPredsLeft; // # of preds not scheduled. - short NumSuccsLeft; // # of succs not scheduled. + 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 hasPhysRegUses : 1; // Has physreg uses. bool hasPhysRegDefs : 1; // Has physreg defs that are being used. + bool hasPhysRegClobbers : 1; // Has any physreg defs, used or not. bool isPending : 1; // True once pending. bool isAvailable : 1; // True once available. bool isScheduled : 1; // True once scheduled. - unsigned CycleBound; // Upper/lower cycle to be scheduled at. - unsigned Cycle; // Once scheduled, the cycle of the op. - unsigned Depth; // Node depth; - unsigned Height; // Node height; + 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. + + 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), - isPending(false), isAvailable(false), isScheduled(false), - CycleBound(0), Cycle(~0u), Depth(0), Height(0), - CopyDstRC(NULL), CopySrcRC(NULL) {} + : Node(node), Instr(0), OrigNode(0), SchedClass(0), NodeNum(nodenum), + NodeQueueId(0), NumPreds(0), NumSuccs(0), NumPredsLeft(0), + NumSuccsLeft(0), WeakPredsLeft(0), WeakSuccsLeft(0), NumRegDefsLeft(0), + Latency(0), isVRegCycle(false), isCall(false), isCallOp(false), + isTwoAddress(false), isCommutable(false), hasPhysRegUses(false), + hasPhysRegDefs(false), hasPhysRegClobbers(false), isPending(false), + isAvailable(false), isScheduled(false), isScheduleHigh(false), + isScheduleLow(false), isCloned(false), SchedulingPref(Sched::None), + isDepthCurrent(false), isHeightCurrent(false), Depth(0), Height(0), + 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), - isPending(false), isAvailable(false), isScheduled(false), - CycleBound(0), Cycle(~0u), Depth(0), Height(0), - CopyDstRC(NULL), CopySrcRC(NULL) {} + : Node(0), Instr(instr), OrigNode(0), SchedClass(0), NodeNum(nodenum), + NodeQueueId(0), NumPreds(0), NumSuccs(0), NumPredsLeft(0), + NumSuccsLeft(0), WeakPredsLeft(0), WeakSuccsLeft(0), NumRegDefsLeft(0), + Latency(0), isVRegCycle(false), isCall(false), isCallOp(false), + isTwoAddress(false), isCommutable(false), hasPhysRegUses(false), + hasPhysRegDefs(false), hasPhysRegClobbers(false), isPending(false), + isAvailable(false), isScheduled(false), isScheduleHigh(false), + isScheduleLow(false), isCloned(false), SchedulingPref(Sched::None), + isDepthCurrent(false), isHeightCurrent(false), Depth(0), Height(0), + TopReadyCycle(0), BotReadyCycle(0), CopyDstRC(NULL), CopySrcRC(NULL) {} + + /// SUnit - Construct a placeholder SUnit. + SUnit() + : Node(0), Instr(0), OrigNode(0), SchedClass(0), NodeNum(BoundaryID), + NodeQueueId(0), NumPreds(0), NumSuccs(0), NumPredsLeft(0), + NumSuccsLeft(0), WeakPredsLeft(0), WeakSuccsLeft(0), NumRegDefsLeft(0), + Latency(0), isVRegCycle(false), isCall(false), isCallOp(false), + isTwoAddress(false), isCommutable(false), hasPhysRegUses(false), + hasPhysRegDefs(false), hasPhysRegClobbers(false), isPending(false), + isAvailable(false), isScheduled(false), isScheduleHigh(false), + isScheduleLow(false), isCloned(false), SchedulingPref(Sched::None), + isDepthCurrent(false), isHeightCurrent(false), Depth(0), Height(0), + TopReadyCycle(0), BotReadyCycle(0), CopyDstRC(NULL), CopySrcRC(NULL) {} + + /// \brief Boundary nodes are placeholders for the boundary of the + /// scheduling region. + /// + /// BoundaryNodes can have DAG edges, including Data edges, but they do not + /// correspond to schedulable entities (e.g. instructions) and do not have a + /// valid ID. Consequently, always check for boundary nodes before accessing + /// an assoicative data structure keyed on node ID. + bool isBoundaryNode() const { return NodeNum == BoundaryID; }; /// setNode - Assign the representative SDNode for this SUnit. /// This may be used during pre-regalloc scheduling. @@ -127,6 +370,10 @@ namespace llvm { 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) { @@ -141,169 +388,189 @@ namespace llvm { return Instr; } - /// addPred - This adds the specified node as a pred of the current node if + /// 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. This returns true if this is a new pred. - bool addPred(SUnit *N, bool isCtrl, bool isArtificial, - unsigned PhyReg = 0, int Cost = 1, bool isAntiDep = false) { - for (unsigned i = 0, e = (unsigned)Preds.size(); i != e; ++i) - if (Preds[i].Dep == N && - Preds[i].isCtrl == isCtrl && Preds[i].isArtificial == isArtificial) - return false; - Preds.push_back(SDep(N, PhyReg, Cost, isCtrl, isArtificial, isAntiDep)); - N->Succs.push_back(SDep(this, PhyReg, Cost, isCtrl, - isArtificial, isAntiDep)); - if (!isCtrl) { - ++NumPreds; - ++N->NumSuccs; - } - if (!N->isScheduled) - ++NumPredsLeft; - if (!isScheduled) - ++N->NumSuccsLeft; - return true; + /// specified node. + bool addPred(const SDep &D, bool Required = true); + + /// 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 + /// the specified node. + void removePred(const SDep &D); + + /// getDepth - Return the depth of this node, which is the length of the + /// maximum path up to any node which has no predecessors. + unsigned getDepth() const { + if (!isDepthCurrent) + const_cast(this)->ComputeDepth(); + return Depth; } - bool removePred(SUnit *N, bool isCtrl, bool isArtificial, bool isAntiDep) { - for (SmallVector::iterator I = Preds.begin(), E = Preds.end(); - I != E; ++I) - if (I->Dep == N && I->isCtrl == isCtrl && I->isArtificial == isArtificial) { - bool FoundSucc = false; - for (SmallVector::iterator II = N->Succs.begin(), - EE = N->Succs.end(); II != EE; ++II) - if (II->Dep == this && - II->isCtrl == isCtrl && II->isArtificial == isArtificial && - II->isAntiDep == isAntiDep) { - FoundSucc = true; - N->Succs.erase(II); - break; - } - assert(FoundSucc && "Mismatching preds / succs lists!"); - Preds.erase(I); - if (!isCtrl) { - --NumPreds; - --N->NumSuccs; - } - if (!N->isScheduled) - --NumPredsLeft; - if (!isScheduled) - --N->NumSuccsLeft; - return true; - } - return false; + /// getHeight - Return the height of this node, which is the length of the + /// maximum path down to any node which has no successors. + unsigned getHeight() const { + if (!isHeightCurrent) + const_cast(this)->ComputeHeight(); + return Height; } + /// setDepthToAtLeast - If NewDepth is greater than this node's + /// depth value, set it to be the new depth value. This also + /// recursively marks successor nodes dirty. + void setDepthToAtLeast(unsigned NewDepth); + + /// setDepthToAtLeast - If NewDepth is greater than this node's + /// depth value, set it to be the new height value. This also + /// recursively marks predecessor nodes dirty. + void setHeightToAtLeast(unsigned NewHeight); + + /// setDepthDirty - Set a flag in this node to indicate that its + /// stored Depth value will require recomputation the next time + /// getDepth() is called. + void setDepthDirty(); + + /// setHeightDirty - Set a flag in this node to indicate that its + /// stored Height value will require recomputation the next time + /// getHeight() is called. + void setHeightDirty(); + + /// isPred - Test if node N is a predecessor of this node. bool isPred(SUnit *N) { for (unsigned i = 0, e = (unsigned)Preds.size(); i != e; ++i) - if (Preds[i].Dep == N) + if (Preds[i].getSUnit() == N) 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) - if (Succs[i].Dep == N) + if (Succs[i].getSUnit() == N) return true; return false; } - + + bool isTopReady() const { + return NumPredsLeft == 0; + } + bool isBottomReady() const { + return NumSuccsLeft == 0; + } + + /// \brief Order this node's predecessor edges such that the critical path + /// edge occurs first. + void biasCriticalPath(); + void dump(const ScheduleDAG *G) const; void dumpAll(const ScheduleDAG *G) const; void print(raw_ostream &O, const ScheduleDAG *G) const; + + private: + void ComputeDepth(); + void ComputeHeight(); }; //===--------------------------------------------------------------------===// /// 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(bool rf = false): + CurCycle(0), HasReadyFilter(rf) {} virtual ~SchedulingPriorityQueue() {} - + + virtual bool isBottomUp() const = 0; + virtual void initNodes(std::vector &SUnits) = 0; virtual void addNode(const SUnit *SU) = 0; virtual void updateNode(const SUnit *SU) = 0; virtual void releaseState() = 0; - virtual unsigned size() const = 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 &Nodes) = 0; + + void push_all(const std::vector &Nodes) { + for (std::vector::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: - SelectionDAG *DAG; // DAG of the current basic block - MachineBasicBlock *BB; // Current basic block const TargetMachine &TM; // Target processor const TargetInstrInfo *TII; // Target instruction information const TargetRegisterInfo *TRI; // Target processor register info - TargetLowering *TLI; // Target lowering info - MachineFunction *MF; // Machine function + MachineFunction &MF; // Machine function MachineRegisterInfo &MRI; // Virtual/real register map - MachineConstantPool *ConstPool; // Target constant pool - std::vector Sequence; // The schedule. Null SUnit*'s - // represent noop instructions. std::vector SUnits; // The scheduling units. + SUnit EntrySU; // Special node for the region entry. + SUnit ExitSU; // Special node for the region exit. - ScheduleDAG(SelectionDAG *dag, MachineBasicBlock *bb, - const TargetMachine &tm); - - virtual ~ScheduleDAG(); - - /// viewGraph - Pop up a GraphViz/gv window with the ScheduleDAG rendered - /// using 'dot'. - /// - void viewGraph(); - - /// Run - perform scheduling. - /// - void Run(); - - /// BuildSchedUnits - Build SUnits and set up their Preds and Succs - /// to form the scheduling dependency graph. - /// - virtual void BuildSchedUnits() = 0; +#ifdef NDEBUG + static const bool StressSched = false; +#else + bool StressSched; +#endif - /// ComputeLatency - Compute node latency. - /// - virtual void ComputeLatency(SUnit *SU) { SU->Latency = 1; } + explicit ScheduleDAG(MachineFunction &mf); - /// CalculateDepths, CalculateHeights - Calculate node depth / height. - /// - void CalculateDepths(); - void CalculateHeights(); + virtual ~ScheduleDAG(); - protected: - /// EmitNoop - Emit a noop instruction. - /// - void EmitNoop(); + /// clearDAG - clear the DAG state (between regions). + void clearDAG(); - public: - virtual MachineBasicBlock *EmitSchedule() = 0; - - void dumpSchedule() const; + /// 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()); + } - /// Schedule - Order nodes according to selected style, filling - /// in the Sequence member. + /// viewGraph - Pop up a GraphViz/gv window with the ScheduleDAG rendered + /// using 'dot'. /// - virtual void Schedule() = 0; + virtual void viewGraph(const Twine &Name, const Twine &Title); + virtual void viewGraph(); virtual void dumpNode(const SUnit *SU) const = 0; @@ -311,38 +578,26 @@ namespace llvm { /// 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 &) 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: - void AddMemOperand(MachineInstr *MI, const MachineMemOperand &MO); - - void EmitCrossRCCopy(SUnit *SU, DenseMap &VRBaseMap); - private: - /// EmitLiveInCopy - Emit a copy for a live in physical register. If the - /// physical register has only a single copy use, then coalesced the copy - /// if possible. - void EmitLiveInCopy(MachineBasicBlock *MBB, - MachineBasicBlock::iterator &InsertPos, - unsigned VirtReg, unsigned PhysReg, - const TargetRegisterClass *RC, - DenseMap &CopyRegMap); - - /// EmitLiveInCopies - If this is the first basic block in the function, - /// and if it has live ins that need to be copied into vregs, emit the - /// copies into the top of the block. - void EmitLiveInCopies(MachineBasicBlock *MBB); + // Return the MCInstrDesc of this SDNode or NULL. + const MCInstrDesc *getNodeDesc(const SDNode *Node) const; }; - class SUnitIterator : public forward_iterator { + class SUnitIterator : public std::iterator { SUnit *Node; unsigned Operand; @@ -354,13 +609,13 @@ namespace llvm { bool operator!=(const SUnitIterator& x) const { return !operator==(x); } const SUnitIterator &operator=(const SUnitIterator &I) { - assert(I.Node == Node && "Cannot assign iterators to two different nodes!"); + assert(I.Node==Node && "Cannot assign iterators to two different nodes!"); Operand = I.Operand; return *this; } pointer operator*() const { - return Node->Preds[Operand].Dep; + return Node->Preds[Operand].getSUnit(); } pointer operator->() const { return operator*(); } @@ -379,8 +634,16 @@ namespace llvm { unsigned getOperand() const { return Operand; } const SUnit *getNode() const { return Node; } - bool isCtrlDep() const { return Node->Preds[Operand].isCtrl; } - bool isArtificialDep() const { return Node->Preds[Operand].isArtificial; } + /// isCtrlDep - Test if this is not an SDep::Data dependence. + bool isCtrlDep() const { + return getSDep().isCtrl(); + } + bool isArtificialDep() const { + return getSDep().isArtificial(); + } + const SDep &getSDep() const { + return Node->Preds[Operand]; + } }; template <> struct GraphTraits { @@ -404,6 +667,73 @@ namespace llvm { return G->SUnits.end(); } }; + + /// ScheduleDAGTopologicalSort is a class that computes a topological + /// ordering for SUnits and provides methods for dynamically updating + /// the ordering as new edges are added. + /// + /// This allows a very fast implementation of IsReachable, for example. + /// + class ScheduleDAGTopologicalSort { + /// SUnits - A reference to the ScheduleDAG's SUnits. + std::vector &SUnits; + SUnit *ExitSU; + + /// Index2Node - Maps topological index to the node number. + std::vector Index2Node; + /// Node2Index - Maps the node number to its topological index. + std::vector Node2Index; + /// Visited - a set of nodes visited during a DFS traversal. + BitVector Visited; + + /// 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); + + /// Shift - reassign topological indexes for the nodes in the DAG + /// to preserve the topological ordering. + void Shift(BitVector& Visited, int LowerBound, int UpperBound); + + /// Allocate - assign the topological index to the node n. + void Allocate(int n, int index); + + public: + ScheduleDAGTopologicalSort(std::vector &SUnits, SUnit *ExitSU); + + /// InitDAGTopologicalSorting - create the initial topological + /// ordering from the DAG to be scheduled. + void InitDAGTopologicalSorting(); + + /// IsReachable - Checks if SU is reachable from TargetSU. + bool IsReachable(const SUnit *SU, const SUnit *TargetSU); + + /// WillCreateCycle - Return true if addPred(TargetSU, SU) creates a cycle. + bool WillCreateCycle(SUnit *TargetSU, SUnit *SU); + + /// 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 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); + + typedef std::vector::iterator iterator; + typedef std::vector::const_iterator const_iterator; + iterator begin() { return Index2Node.begin(); } + const_iterator begin() const { return Index2Node.begin(); } + iterator end() { return Index2Node.end(); } + const_iterator end() const { return Index2Node.end(); } + + typedef std::vector::reverse_iterator reverse_iterator; + typedef std::vector::const_reverse_iterator const_reverse_iterator; + reverse_iterator rbegin() { return Index2Node.rbegin(); } + const_reverse_iterator rbegin() const { return Index2Node.rbegin(); } + reverse_iterator rend() { return Index2Node.rend(); } + const_reverse_iterator rend() const { return Index2Node.rend(); } + }; } #endif