llvm-6502/include/llvm/CodeGen/ScheduleDAG.h
Dan Gohman c6c391dadd Create a new class, MemOperand, for describing memory references
in the backend. Introduce a new SDNode type, MemOperandSDNode, for
holding a MemOperand in the SelectionDAG IR, and add a MemOperand
list to MachineInstr, and code to manage them. Remove the offset
field from SrcValueSDNode; uses of SrcValueSDNode that were using
it are all all using MemOperandSDNode now.

Also, begin updating some getLoad and getStore calls to use the
PseudoSourceValue objects.

Most of this was written by Florian Brander, some
reorganization and updating to TOT by me.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@46585 91177308-0d34-0410-b5e6-96231b3b80d8
2008-01-31 00:25:39 +00:00

457 lines
18 KiB
C++

//===------- llvm/CodeGen/ScheduleDAG.h - Common Base Class------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements the ScheduleDAG class, which is used as the common
// base class for SelectionDAG-based instruction scheduler.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_CODEGEN_SCHEDULEDAG_H
#define LLVM_CODEGEN_SCHEDULEDAG_H
#include "llvm/CodeGen/SelectionDAG.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/GraphTraits.h"
#include "llvm/ADT/SmallSet.h"
namespace llvm {
struct InstrStage;
struct SUnit;
class MachineConstantPool;
class MachineFunction;
class MachineModuleInfo;
class MachineRegisterInfo;
class MachineInstr;
class MRegisterInfo;
class SelectionDAG;
class SelectionDAGISel;
class TargetInstrInfo;
class TargetInstrDesc;
class TargetMachine;
class TargetRegisterClass;
/// HazardRecognizer - This determines whether or not an instruction can be
/// issued this cycle, and whether or not a noop needs to be inserted to handle
/// the hazard.
class HazardRecognizer {
public:
virtual ~HazardRecognizer();
enum HazardType {
NoHazard, // This instruction can be emitted at this cycle.
Hazard, // This instruction can't be emitted at this cycle.
NoopHazard // This instruction can't be emitted, and needs noops.
};
/// getHazardType - Return the hazard type of emitting this node. There are
/// three possible results. Either:
/// * NoHazard: it is legal to issue this instruction on this cycle.
/// * Hazard: issuing this instruction would stall the machine. If some
/// other instruction is available, issue it first.
/// * NoopHazard: issuing this instruction would break the program. If
/// some other instruction can be issued, do so, otherwise issue a noop.
virtual HazardType getHazardType(SDNode *Node) {
return NoHazard;
}
/// EmitInstruction - This callback is invoked when an instruction is
/// emitted, to advance the hazard state.
virtual void EmitInstruction(SDNode *Node) {
}
/// AdvanceCycle - This callback is invoked when no instructions can be
/// issued on this cycle without a hazard. This should increment the
/// internal state of the hazard recognizer so that previously "Hazard"
/// instructions will now not be hazards.
virtual void AdvanceCycle() {
}
/// EmitNoop - This callback is invoked when a noop was added to the
/// instruction stream.
virtual void EmitNoop() {
}
};
/// 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 phy register dependency.
int Cost; // Cost of the dependency.
bool isCtrl : 1; // True iff it's a control dependency.
bool isSpecial : 1; // True iff it's a special ctrl dep added during sched.
SDep(SUnit *d, unsigned r, int t, bool c, bool s)
: Dep(d), Reg(r), Cost(t), isCtrl(c), isSpecial(s) {}
};
/// SUnit - Scheduling unit. It's an wrapper around either a single SDNode or
/// a group of nodes flagged together.
struct SUnit {
SDNode *Node; // Representative node.
SmallVector<SDNode*,4> FlaggedNodes;// All nodes flagged to Node.
unsigned InstanceNo; // Instance#. One SDNode can be multiple
// SUnit due to cloning.
// 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.
SmallVector<SDep, 4> Preds; // All sunit predecessors.
SmallVector<SDep, 4> Succs; // All sunit successors.
typedef SmallVector<SDep, 4>::iterator pred_iterator;
typedef SmallVector<SDep, 4>::iterator succ_iterator;
typedef SmallVector<SDep, 4>::const_iterator const_pred_iterator;
typedef SmallVector<SDep, 4>::const_iterator const_succ_iterator;
unsigned NodeNum; // Entry # of node in the node vector.
unsigned short Latency; // Node latency.
short NumPreds; // # of preds.
short NumSuccs; // # of sucss.
short NumPredsLeft; // # of preds not scheduled.
short NumSuccsLeft; // # of succs not scheduled.
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 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;
const TargetRegisterClass *CopyDstRC; // Is a special copy node if not null.
const TargetRegisterClass *CopySrcRC;
SUnit(SDNode *node, unsigned nodenum)
: Node(node), InstanceNo(0), NodeNum(nodenum), 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(0), Depth(0), Height(0),
CopyDstRC(NULL), CopySrcRC(NULL) {}
/// addPred - This adds the specified node as a pred of the current node if
/// not already. This returns true if this is a new pred.
bool addPred(SUnit *N, bool isCtrl, bool isSpecial,
unsigned PhyReg = 0, int Cost = 1) {
for (unsigned i = 0, e = Preds.size(); i != e; ++i)
if (Preds[i].Dep == N &&
Preds[i].isCtrl == isCtrl && Preds[i].isSpecial == isSpecial)
return false;
Preds.push_back(SDep(N, PhyReg, Cost, isCtrl, isSpecial));
N->Succs.push_back(SDep(this, PhyReg, Cost, isCtrl, isSpecial));
if (!isCtrl) {
++NumPreds;
++N->NumSuccs;
}
if (!N->isScheduled)
++NumPredsLeft;
if (!isScheduled)
++N->NumSuccsLeft;
return true;
}
bool removePred(SUnit *N, bool isCtrl, bool isSpecial) {
for (SmallVector<SDep, 4>::iterator I = Preds.begin(), E = Preds.end();
I != E; ++I)
if (I->Dep == N && I->isCtrl == isCtrl && I->isSpecial == isSpecial) {
bool FoundSucc = false;
for (SmallVector<SDep, 4>::iterator II = N->Succs.begin(),
EE = N->Succs.end(); II != EE; ++II)
if (II->Dep == this &&
II->isCtrl == isCtrl && II->isSpecial == isSpecial) {
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;
}
bool isPred(SUnit *N) {
for (unsigned i = 0, e = Preds.size(); i != e; ++i)
if (Preds[i].Dep == N)
return true;
return false;
}
bool isSucc(SUnit *N) {
for (unsigned i = 0, e = Succs.size(); i != e; ++i)
if (Succs[i].Dep == N)
return true;
return false;
}
void dump(const SelectionDAG *G) const;
void dumpAll(const SelectionDAG *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
/// 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 {
public:
virtual ~SchedulingPriorityQueue() {}
virtual void initNodes(DenseMap<SDNode*, std::vector<SUnit*> > &SUMap,
std::vector<SUnit> &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;
virtual void push(SUnit *U) = 0;
virtual void push_all(const std::vector<SUnit *> &Nodes) = 0;
virtual SUnit *pop() = 0;
virtual void remove(SUnit *SU) = 0;
/// ScheduledNode - As each node is scheduled, this method is invoked. This
/// allows the priority function to adjust the priority of node that have
/// already been emitted.
virtual void ScheduledNode(SUnit *Node) {}
virtual void UnscheduledNode(SUnit *Node) {}
};
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 MRegisterInfo *MRI; // Target processor register info
MachineFunction *MF; // Machine function
MachineRegisterInfo &RegInfo; // Virtual/real register map
MachineConstantPool *ConstPool; // Target constant pool
std::vector<SUnit*> Sequence; // The schedule. Null SUnit*'s
// represent noop instructions.
DenseMap<SDNode*, std::vector<SUnit*> > SUnitMap;
// SDNode to SUnit mapping (n -> n).
std::vector<SUnit> SUnits; // The scheduling units.
SmallSet<SDNode*, 16> CommuteSet; // Nodes the should be commuted.
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.
///
MachineBasicBlock *Run();
/// isPassiveNode - Return true if the node is a non-scheduled leaf.
///
static bool isPassiveNode(SDNode *Node) {
if (isa<ConstantSDNode>(Node)) return true;
if (isa<RegisterSDNode>(Node)) return true;
if (isa<GlobalAddressSDNode>(Node)) return true;
if (isa<BasicBlockSDNode>(Node)) return true;
if (isa<FrameIndexSDNode>(Node)) return true;
if (isa<ConstantPoolSDNode>(Node)) return true;
if (isa<JumpTableSDNode>(Node)) return true;
if (isa<ExternalSymbolSDNode>(Node)) return true;
if (isa<MemOperandSDNode>(Node)) return true;
return false;
}
/// NewSUnit - Creates a new SUnit and return a ptr to it.
///
SUnit *NewSUnit(SDNode *N) {
SUnits.push_back(SUnit(N, SUnits.size()));
return &SUnits.back();
}
/// Clone - Creates a clone of the specified SUnit. It does not copy the
/// predecessors / successors info nor the temporary scheduling states.
SUnit *Clone(SUnit *N);
/// BuildSchedUnits - Build SUnits from the selection dag that we are input.
/// This SUnit graph is similar to the SelectionDAG, but represents flagged
/// together nodes with a single SUnit.
void BuildSchedUnits();
/// ComputeLatency - Compute node latency.
///
void ComputeLatency(SUnit *SU);
/// CalculateDepths, CalculateHeights - Calculate node depth / height.
///
void CalculateDepths();
void CalculateHeights();
/// CountResults - The results of target nodes have register or immediate
/// operands first, then an optional chain, and optional flag operands
/// (which do not go into the machine instrs.)
static unsigned CountResults(SDNode *Node);
/// CountOperands - The inputs to target nodes have any actual inputs first,
/// followed by optional memory operands chain operand, then flag operands.
/// Compute the number of actual operands that will go into the machine
/// instr.
static unsigned CountOperands(SDNode *Node);
/// CountMemOperands - Find the index of the last MemOperandSDNode
static unsigned CountMemOperands(SDNode *Node);
/// EmitNode - Generate machine code for an node and needed dependencies.
/// VRBaseMap contains, for each already emitted node, the first virtual
/// register number for the results of the node.
///
void EmitNode(SDNode *Node, unsigned InstNo,
DenseMap<SDOperand, unsigned> &VRBaseMap);
/// EmitNoop - Emit a noop instruction.
///
void EmitNoop();
void EmitCrossRCCopy(SUnit *SU, DenseMap<SUnit*, unsigned> &VRBaseMap);
/// EmitCopyFromReg - Generate machine code for an CopyFromReg node or an
/// implicit physical register output.
void EmitCopyFromReg(SDNode *Node, unsigned ResNo, unsigned InstNo,
unsigned SrcReg,
DenseMap<SDOperand, unsigned> &VRBaseMap);
void CreateVirtualRegisters(SDNode *Node, MachineInstr *MI,
const TargetInstrDesc &II,
DenseMap<SDOperand, unsigned> &VRBaseMap);
void EmitSchedule();
void dumpSchedule() const;
/// Schedule - Order nodes according to selected style.
///
virtual void Schedule() {}
private:
/// EmitSubregNode - Generate machine code for subreg nodes.
///
void EmitSubregNode(SDNode *Node,
DenseMap<SDOperand, unsigned> &VRBaseMap);
void AddOperand(MachineInstr *MI, SDOperand Op, unsigned IIOpNum,
const TargetInstrDesc *II,
DenseMap<SDOperand, unsigned> &VRBaseMap);
void AddMemOperand(MachineInstr *MI, const MemOperand &MO);
};
/// createBURRListDAGScheduler - This creates a bottom up register usage
/// reduction list scheduler.
ScheduleDAG* createBURRListDAGScheduler(SelectionDAGISel *IS,
SelectionDAG *DAG,
MachineBasicBlock *BB);
/// createTDRRListDAGScheduler - This creates a top down register usage
/// reduction list scheduler.
ScheduleDAG* createTDRRListDAGScheduler(SelectionDAGISel *IS,
SelectionDAG *DAG,
MachineBasicBlock *BB);
/// createTDListDAGScheduler - This creates a top-down list scheduler with
/// a hazard recognizer.
ScheduleDAG* createTDListDAGScheduler(SelectionDAGISel *IS,
SelectionDAG *DAG,
MachineBasicBlock *BB);
/// createDefaultScheduler - This creates an instruction scheduler appropriate
/// for the target.
ScheduleDAG* createDefaultScheduler(SelectionDAGISel *IS,
SelectionDAG *DAG,
MachineBasicBlock *BB);
class SUnitIterator : public forward_iterator<SUnit, ptrdiff_t> {
SUnit *Node;
unsigned Operand;
SUnitIterator(SUnit *N, unsigned Op) : Node(N), Operand(Op) {}
public:
bool operator==(const SUnitIterator& x) const {
return Operand == x.Operand;
}
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!");
Operand = I.Operand;
return *this;
}
pointer operator*() const {
return Node->Preds[Operand].Dep;
}
pointer operator->() const { return operator*(); }
SUnitIterator& operator++() { // Preincrement
++Operand;
return *this;
}
SUnitIterator operator++(int) { // Postincrement
SUnitIterator tmp = *this; ++*this; return tmp;
}
static SUnitIterator begin(SUnit *N) { return SUnitIterator(N, 0); }
static SUnitIterator end (SUnit *N) {
return SUnitIterator(N, N->Preds.size());
}
unsigned getOperand() const { return Operand; }
const SUnit *getNode() const { return Node; }
bool isCtrlDep() const { return Node->Preds[Operand].isCtrl; }
};
template <> struct GraphTraits<SUnit*> {
typedef SUnit NodeType;
typedef SUnitIterator ChildIteratorType;
static inline NodeType *getEntryNode(SUnit *N) { return N; }
static inline ChildIteratorType child_begin(NodeType *N) {
return SUnitIterator::begin(N);
}
static inline ChildIteratorType child_end(NodeType *N) {
return SUnitIterator::end(N);
}
};
template <> struct GraphTraits<ScheduleDAG*> : public GraphTraits<SUnit*> {
typedef std::vector<SUnit>::iterator nodes_iterator;
static nodes_iterator nodes_begin(ScheduleDAG *G) {
return G->SUnits.begin();
}
static nodes_iterator nodes_end(ScheduleDAG *G) {
return G->SUnits.end();
}
};
}
#endif