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Hoist the HazardRecognizer out of the ScheduleDAGList.cpp file to where 

targets can implement them.  Make the top-down scheduler non-g5-specific.

Remove the old testing hazard recognizer.

llvm-svn: 26569
This commit is contained in:
Chris Lattner 2006-03-06 00:22:00 +00:00
parent 5733f37f17
commit 47639dbb93
2 changed files with 32 additions and 112 deletions
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130
llvm/lib/CodeGen/SelectionDAG/ScheduleDAGList.cpp
View File

@ -164,51 +164,6 @@ struct ls_rr_sort : public std::binary_function<SUnit*, SUnit*, bool> {
};
/// 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.
namespace {
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() {
}
};
}
/// ScheduleDAGList - List scheduler.
class ScheduleDAGList : public ScheduleDAG {
private:
@ -226,7 +181,7 @@ private:
bool isBottomUp;
/// HazardRec - The hazard recognizer to use.
HazardRecognizer *HazardRec;
HazardRecognizer &HazardRec;
typedef std::priority_queue<SUnit*, std::vector<SUnit*>, ls_rr_sort>
AvailableQueueTy;
@ -234,11 +189,10 @@ private:
public:
ScheduleDAGList(SelectionDAG &dag, MachineBasicBlock *bb,
const TargetMachine &tm, bool isbottomup,
HazardRecognizer *HR = 0)
HazardRecognizer &HR)
: ScheduleDAG(listSchedulingBURR, dag, bb, tm),
CurrCycle(0), HeadSUnit(NULL), TailSUnit(NULL), isBottomUp(isbottomup) {
if (HR == 0) HR = new HazardRecognizer();
HazardRec = HR;
CurrCycle(0), HeadSUnit(NULL), TailSUnit(NULL), isBottomUp(isbottomup),
HazardRec(HR) {
}
~ScheduleDAGList() {
@ -248,8 +202,6 @@ public:
delete SU;
SU = NextSU;
}
delete HazardRec;
}
void Schedule();
@ -271,6 +223,8 @@ private:
};
} // end namespace
HazardRecognizer::~HazardRecognizer() {}
/// NewSUnit - Creates a new SUnit and return a ptr to it.
SUnit *ScheduleDAGList::NewSUnit(SDNode *N) {
@ -465,11 +419,13 @@ void ScheduleDAGList::ListScheduleBottomUp() {
void ScheduleDAGList::ListScheduleTopDown() {
// Available queue.
AvailableQueueTy Available;
HazardRec.StartBasicBlock();
// Emit the entry node first.
SUnit *Entry = SUnitMap[DAG.getEntryNode().Val];
ScheduleNodeTopDown(Available, Entry);
HazardRec->EmitInstruction(Entry->Node);
HazardRec.EmitInstruction(Entry->Node);
// All leaves to Available queue.
for (SUnit *SU = HeadSUnit; SU != NULL; SU = SU->Next) {
@ -489,7 +445,7 @@ void ScheduleDAGList::ListScheduleTopDown() {
SUnit *CurrNode = Available.top();
Available.pop();
HazardRecognizer::HazardType HT =
HazardRec->getHazardType(CurrNode->Node);
HazardRec.getHazardType(CurrNode->Node);
if (HT == HazardRecognizer::NoHazard) {
FoundNode = CurrNode;
break;
@ -510,19 +466,19 @@ void ScheduleDAGList::ListScheduleTopDown() {
// If we found a node to schedule, do it now.
if (FoundNode) {
ScheduleNodeTopDown(Available, FoundNode);
HazardRec->EmitInstruction(FoundNode->Node);
HazardRec.EmitInstruction(FoundNode->Node);
} else if (!HasNoopHazards) {
// Otherwise, we have a pipeline stall, but no other problem, just advance
// the current cycle and try again.
DEBUG(std::cerr << "*** Advancing cycle, no work to do");
HazardRec->AdvanceCycle();
HazardRec.AdvanceCycle();
++NumStalls;
} else {
// Otherwise, we have no instructions to issue and we have instructions
// that will fault if we don't do this right. This is the case for
// processors without pipeline interlocks and other cases.
DEBUG(std::cerr << "*** Emitting noop");
HazardRec->EmitNoop();
HazardRec.EmitNoop();
Sequence.push_back(0); // NULL SUnit* -> noop
++NumNoops;
}
@ -720,7 +676,7 @@ void ScheduleDAGList::Schedule() {
// Build scheduling units.
BuildSchedUnits();
// Calculate node prirorities.
// Calculate node priorities.
CalculatePriorities();
// Execute the actual scheduling loop Top-Down or Bottom-Up as appropriate.
@ -739,56 +695,14 @@ void ScheduleDAGList::Schedule() {
llvm::ScheduleDAG* llvm::createBURRListDAGScheduler(SelectionDAG &DAG,
MachineBasicBlock *BB) {
return new ScheduleDAGList(DAG, BB, DAG.getTarget(), true);
HazardRecognizer HR;
return new ScheduleDAGList(DAG, BB, DAG.getTarget(), true, HR);
}
/// G5HazardRecognizer - A hazard recognizer for the PowerPC G5 processor.
/// FIXME: Move to the PowerPC backend.
class G5HazardRecognizer : public HazardRecognizer {
// Totally bogus hazard recognizer, used to test noop insertion. This requires
// a noop between copyfromreg's.
unsigned EmittedCopyFromReg;
public:
G5HazardRecognizer() {
EmittedCopyFromReg = 0;
}
virtual HazardType getHazardType(SDNode *Node) {
if (Node->getOpcode() == ISD::CopyFromReg && EmittedCopyFromReg)
return NoopHazard;
return NoHazard;
}
/// EmitInstruction - This callback is invoked when an instruction is
/// emitted, to advance the hazard state.
virtual void EmitInstruction(SDNode *Node) {
if (Node->getOpcode() == ISD::CopyFromReg) {
EmittedCopyFromReg = 5;
} else if (EmittedCopyFromReg) {
--EmittedCopyFromReg;
}
}
/// 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() {
--EmittedCopyFromReg;
}
};
/// createTDG5ListDAGScheduler - This creates a top-down list scheduler for
/// the PowerPC G5. FIXME: pull the priority function out into the PPC
/// backend!
ScheduleDAG* llvm::createTDG5ListDAGScheduler(SelectionDAG &DAG,
MachineBasicBlock *BB) {
return new ScheduleDAGList(DAG, BB, DAG.getTarget(), false,
new G5HazardRecognizer());
/// createTDListDAGScheduler - This creates a top-down list scheduler with the
/// specified hazard recognizer.
ScheduleDAG* llvm::createTDListDAGScheduler(SelectionDAG &DAG,
MachineBasicBlock *BB,
HazardRecognizer &HR) {
return new ScheduleDAGList(DAG, BB, DAG.getTarget(), false, HR);
}

14
llvm/lib/CodeGen/SelectionDAG/SelectionDAGISel.cpp
View File

@ -76,8 +76,8 @@ namespace {
"except using generic latency"),
clEnumValN(listSchedulingBURR, "list-burr",
"Bottom up register reduction list scheduling"),
clEnumValN(listSchedulingG5, "list-g5",
"Scheduling for the PowerPC G5"),
clEnumValN(listSchedulingTD, "list-td",
"Top-down list scheduler"),
clEnumValEnd));
} // namespace
@ -2473,14 +2473,20 @@ void SelectionDAGISel::ScheduleAndEmitDAG(SelectionDAG &DAG) {
case listSchedulingBURR:
SL = createBURRListDAGScheduler(DAG, BB);
break;
case listSchedulingG5:
SL = createTDG5ListDAGScheduler(DAG, BB);
case listSchedulingTD:
SL = createTDListDAGScheduler(DAG, BB, GetTargetHazardRecognizer());
break;
}
BB = SL->Run();
delete SL;
}
HazardRecognizer &SelectionDAGISel::
GetTargetHazardRecognizer() {
static HazardRecognizer DefaultRecognizer;
return DefaultRecognizer;
}
/// SelectInlineAsmMemoryOperands - Calls to this are automatically generated
/// by tblgen. Others should not call it.
void SelectionDAGISel::