mirror of
https://github.com/RPCSX/llvm.git
synced 2024-12-03 17:31:50 +00:00
217a56948a
Patch by Axel Davy (axel.davy@normalesup.org) Differential revision: https://reviews.llvm.org/D30626 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@298896 91177308-0d34-0410-b5e6-96231b3b80d8
695 lines
20 KiB
C++
695 lines
20 KiB
C++
//===- ScheduleDAG.cpp - Implement the ScheduleDAG class ------------------===//
|
|
//
|
|
// The LLVM Compiler Infrastructure
|
|
//
|
|
// This file is distributed under the University of Illinois Open Source
|
|
// License. See LICENSE.TXT for details.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
/// \file Implements the ScheduleDAG class, which is a base class used by
|
|
/// scheduling implementation classes.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#include "llvm/ADT/iterator_range.h"
|
|
#include "llvm/ADT/SmallVector.h"
|
|
#include "llvm/ADT/STLExtras.h"
|
|
#include "llvm/CodeGen/MachineFunction.h"
|
|
#include "llvm/CodeGen/ScheduleDAG.h"
|
|
#include "llvm/CodeGen/ScheduleHazardRecognizer.h"
|
|
#include "llvm/CodeGen/SelectionDAGNodes.h"
|
|
#include "llvm/Support/CommandLine.h"
|
|
#include "llvm/Support/Compiler.h"
|
|
#include "llvm/Support/Debug.h"
|
|
#include "llvm/Support/raw_ostream.h"
|
|
#include "llvm/Target/TargetInstrInfo.h"
|
|
#include "llvm/Target/TargetRegisterInfo.h"
|
|
#include "llvm/Target/TargetSubtargetInfo.h"
|
|
#include <algorithm>
|
|
#include <cassert>
|
|
#include <iterator>
|
|
#include <limits>
|
|
#include <utility>
|
|
#include <vector>
|
|
|
|
using namespace llvm;
|
|
|
|
#define DEBUG_TYPE "pre-RA-sched"
|
|
|
|
#ifndef NDEBUG
|
|
static cl::opt<bool> StressSchedOpt(
|
|
"stress-sched", cl::Hidden, cl::init(false),
|
|
cl::desc("Stress test instruction scheduling"));
|
|
#endif
|
|
|
|
void SchedulingPriorityQueue::anchor() {}
|
|
|
|
ScheduleDAG::ScheduleDAG(MachineFunction &mf)
|
|
: TM(mf.getTarget()), TII(mf.getSubtarget().getInstrInfo()),
|
|
TRI(mf.getSubtarget().getRegisterInfo()), MF(mf),
|
|
MRI(mf.getRegInfo()) {
|
|
#ifndef NDEBUG
|
|
StressSched = StressSchedOpt;
|
|
#endif
|
|
}
|
|
|
|
ScheduleDAG::~ScheduleDAG() = default;
|
|
|
|
void ScheduleDAG::clearDAG() {
|
|
SUnits.clear();
|
|
EntrySU = SUnit();
|
|
ExitSU = SUnit();
|
|
}
|
|
|
|
const MCInstrDesc *ScheduleDAG::getNodeDesc(const SDNode *Node) const {
|
|
if (!Node || !Node->isMachineOpcode()) return nullptr;
|
|
return &TII->get(Node->getMachineOpcode());
|
|
}
|
|
|
|
bool SUnit::addPred(const SDep &D, bool Required) {
|
|
// If this node already has this dependence, don't add a redundant one.
|
|
for (SDep &PredDep : Preds) {
|
|
// Zero-latency weak edges may be added purely for heuristic ordering. Don't
|
|
// add them if another kind of edge already exists.
|
|
if (!Required && PredDep.getSUnit() == D.getSUnit())
|
|
return false;
|
|
if (PredDep.overlaps(D)) {
|
|
// Extend the latency if needed. Equivalent to
|
|
// removePred(PredDep) + addPred(D).
|
|
if (PredDep.getLatency() < D.getLatency()) {
|
|
SUnit *PredSU = PredDep.getSUnit();
|
|
// Find the corresponding successor in N.
|
|
SDep ForwardD = PredDep;
|
|
ForwardD.setSUnit(this);
|
|
for (SDep &SuccDep : PredSU->Succs) {
|
|
if (SuccDep == ForwardD) {
|
|
SuccDep.setLatency(D.getLatency());
|
|
break;
|
|
}
|
|
}
|
|
PredDep.setLatency(D.getLatency());
|
|
}
|
|
return false;
|
|
}
|
|
}
|
|
// Now add a corresponding succ to N.
|
|
SDep P = D;
|
|
P.setSUnit(this);
|
|
SUnit *N = D.getSUnit();
|
|
// Update the bookkeeping.
|
|
if (D.getKind() == SDep::Data) {
|
|
assert(NumPreds < std::numeric_limits<unsigned>::max() &&
|
|
"NumPreds will overflow!");
|
|
assert(N->NumSuccs < std::numeric_limits<unsigned>::max() &&
|
|
"NumSuccs will overflow!");
|
|
++NumPreds;
|
|
++N->NumSuccs;
|
|
}
|
|
if (!N->isScheduled) {
|
|
if (D.isWeak()) {
|
|
++WeakPredsLeft;
|
|
}
|
|
else {
|
|
assert(NumPredsLeft < std::numeric_limits<unsigned>::max() &&
|
|
"NumPredsLeft will overflow!");
|
|
++NumPredsLeft;
|
|
}
|
|
}
|
|
if (!isScheduled) {
|
|
if (D.isWeak()) {
|
|
++N->WeakSuccsLeft;
|
|
}
|
|
else {
|
|
assert(N->NumSuccsLeft < std::numeric_limits<unsigned>::max() &&
|
|
"NumSuccsLeft will overflow!");
|
|
++N->NumSuccsLeft;
|
|
}
|
|
}
|
|
Preds.push_back(D);
|
|
N->Succs.push_back(P);
|
|
if (P.getLatency() != 0) {
|
|
this->setDepthDirty();
|
|
N->setHeightDirty();
|
|
}
|
|
return true;
|
|
}
|
|
|
|
void SUnit::removePred(const SDep &D) {
|
|
// Find the matching predecessor.
|
|
SmallVectorImpl<SDep>::iterator I = llvm::find(Preds, D);
|
|
if (I == Preds.end())
|
|
return;
|
|
// Find the corresponding successor in N.
|
|
SDep P = D;
|
|
P.setSUnit(this);
|
|
SUnit *N = D.getSUnit();
|
|
SmallVectorImpl<SDep>::iterator Succ = llvm::find(N->Succs, P);
|
|
assert(Succ != N->Succs.end() && "Mismatching preds / succs lists!");
|
|
N->Succs.erase(Succ);
|
|
Preds.erase(I);
|
|
// Update the bookkeeping.
|
|
if (P.getKind() == SDep::Data) {
|
|
assert(NumPreds > 0 && "NumPreds will underflow!");
|
|
assert(N->NumSuccs > 0 && "NumSuccs will underflow!");
|
|
--NumPreds;
|
|
--N->NumSuccs;
|
|
}
|
|
if (!N->isScheduled) {
|
|
if (D.isWeak())
|
|
--WeakPredsLeft;
|
|
else {
|
|
assert(NumPredsLeft > 0 && "NumPredsLeft will underflow!");
|
|
--NumPredsLeft;
|
|
}
|
|
}
|
|
if (!isScheduled) {
|
|
if (D.isWeak())
|
|
--N->WeakSuccsLeft;
|
|
else {
|
|
assert(N->NumSuccsLeft > 0 && "NumSuccsLeft will underflow!");
|
|
--N->NumSuccsLeft;
|
|
}
|
|
}
|
|
if (P.getLatency() != 0) {
|
|
this->setDepthDirty();
|
|
N->setHeightDirty();
|
|
}
|
|
}
|
|
|
|
void SUnit::setDepthDirty() {
|
|
if (!isDepthCurrent) return;
|
|
SmallVector<SUnit*, 8> WorkList;
|
|
WorkList.push_back(this);
|
|
do {
|
|
SUnit *SU = WorkList.pop_back_val();
|
|
SU->isDepthCurrent = false;
|
|
for (SDep &SuccDep : SU->Succs) {
|
|
SUnit *SuccSU = SuccDep.getSUnit();
|
|
if (SuccSU->isDepthCurrent)
|
|
WorkList.push_back(SuccSU);
|
|
}
|
|
} while (!WorkList.empty());
|
|
}
|
|
|
|
void SUnit::setHeightDirty() {
|
|
if (!isHeightCurrent) return;
|
|
SmallVector<SUnit*, 8> WorkList;
|
|
WorkList.push_back(this);
|
|
do {
|
|
SUnit *SU = WorkList.pop_back_val();
|
|
SU->isHeightCurrent = false;
|
|
for (SDep &PredDep : SU->Preds) {
|
|
SUnit *PredSU = PredDep.getSUnit();
|
|
if (PredSU->isHeightCurrent)
|
|
WorkList.push_back(PredSU);
|
|
}
|
|
} while (!WorkList.empty());
|
|
}
|
|
|
|
void SUnit::setDepthToAtLeast(unsigned NewDepth) {
|
|
if (NewDepth <= getDepth())
|
|
return;
|
|
setDepthDirty();
|
|
Depth = NewDepth;
|
|
isDepthCurrent = true;
|
|
}
|
|
|
|
void SUnit::setHeightToAtLeast(unsigned NewHeight) {
|
|
if (NewHeight <= getHeight())
|
|
return;
|
|
setHeightDirty();
|
|
Height = NewHeight;
|
|
isHeightCurrent = true;
|
|
}
|
|
|
|
/// Calculates the maximal path from the node to the exit.
|
|
void SUnit::ComputeDepth() {
|
|
SmallVector<SUnit*, 8> WorkList;
|
|
WorkList.push_back(this);
|
|
do {
|
|
SUnit *Cur = WorkList.back();
|
|
|
|
bool Done = true;
|
|
unsigned MaxPredDepth = 0;
|
|
for (const SDep &PredDep : Cur->Preds) {
|
|
SUnit *PredSU = PredDep.getSUnit();
|
|
if (PredSU->isDepthCurrent)
|
|
MaxPredDepth = std::max(MaxPredDepth,
|
|
PredSU->Depth + PredDep.getLatency());
|
|
else {
|
|
Done = false;
|
|
WorkList.push_back(PredSU);
|
|
}
|
|
}
|
|
|
|
if (Done) {
|
|
WorkList.pop_back();
|
|
if (MaxPredDepth != Cur->Depth) {
|
|
Cur->setDepthDirty();
|
|
Cur->Depth = MaxPredDepth;
|
|
}
|
|
Cur->isDepthCurrent = true;
|
|
}
|
|
} while (!WorkList.empty());
|
|
}
|
|
|
|
/// Calculates the maximal path from the node to the entry.
|
|
void SUnit::ComputeHeight() {
|
|
SmallVector<SUnit*, 8> WorkList;
|
|
WorkList.push_back(this);
|
|
do {
|
|
SUnit *Cur = WorkList.back();
|
|
|
|
bool Done = true;
|
|
unsigned MaxSuccHeight = 0;
|
|
for (const SDep &SuccDep : Cur->Succs) {
|
|
SUnit *SuccSU = SuccDep.getSUnit();
|
|
if (SuccSU->isHeightCurrent)
|
|
MaxSuccHeight = std::max(MaxSuccHeight,
|
|
SuccSU->Height + SuccDep.getLatency());
|
|
else {
|
|
Done = false;
|
|
WorkList.push_back(SuccSU);
|
|
}
|
|
}
|
|
|
|
if (Done) {
|
|
WorkList.pop_back();
|
|
if (MaxSuccHeight != Cur->Height) {
|
|
Cur->setHeightDirty();
|
|
Cur->Height = MaxSuccHeight;
|
|
}
|
|
Cur->isHeightCurrent = true;
|
|
}
|
|
} while (!WorkList.empty());
|
|
}
|
|
|
|
void SUnit::biasCriticalPath() {
|
|
if (NumPreds < 2)
|
|
return;
|
|
|
|
SUnit::pred_iterator BestI = Preds.begin();
|
|
unsigned MaxDepth = BestI->getSUnit()->getDepth();
|
|
for (SUnit::pred_iterator I = std::next(BestI), E = Preds.end(); I != E;
|
|
++I) {
|
|
if (I->getKind() == SDep::Data && I->getSUnit()->getDepth() > MaxDepth)
|
|
BestI = I;
|
|
}
|
|
if (BestI != Preds.begin())
|
|
std::swap(*Preds.begin(), *BestI);
|
|
}
|
|
|
|
#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
|
|
LLVM_DUMP_METHOD
|
|
void SUnit::print(raw_ostream &OS, const ScheduleDAG *DAG) const {
|
|
if (this == &DAG->ExitSU)
|
|
OS << "ExitSU";
|
|
else if (this == &DAG->EntrySU)
|
|
OS << "EntrySU";
|
|
else
|
|
OS << "SU(" << NodeNum << ")";
|
|
}
|
|
|
|
LLVM_DUMP_METHOD void SUnit::dump(const ScheduleDAG *G) const {
|
|
print(dbgs(), G);
|
|
dbgs() << ": ";
|
|
G->dumpNode(this);
|
|
}
|
|
|
|
LLVM_DUMP_METHOD void SUnit::dumpAll(const ScheduleDAG *G) const {
|
|
dump(G);
|
|
|
|
dbgs() << " # preds left : " << NumPredsLeft << "\n";
|
|
dbgs() << " # succs left : " << NumSuccsLeft << "\n";
|
|
if (WeakPredsLeft)
|
|
dbgs() << " # weak preds left : " << WeakPredsLeft << "\n";
|
|
if (WeakSuccsLeft)
|
|
dbgs() << " # weak succs left : " << WeakSuccsLeft << "\n";
|
|
dbgs() << " # rdefs left : " << NumRegDefsLeft << "\n";
|
|
dbgs() << " Latency : " << Latency << "\n";
|
|
dbgs() << " Depth : " << getDepth() << "\n";
|
|
dbgs() << " Height : " << getHeight() << "\n";
|
|
|
|
if (Preds.size() != 0) {
|
|
dbgs() << " Predecessors:\n";
|
|
for (const SDep &SuccDep : Preds) {
|
|
dbgs() << " ";
|
|
switch (SuccDep.getKind()) {
|
|
case SDep::Data: dbgs() << "data "; break;
|
|
case SDep::Anti: dbgs() << "anti "; break;
|
|
case SDep::Output: dbgs() << "out "; break;
|
|
case SDep::Order: dbgs() << "ord "; break;
|
|
}
|
|
SuccDep.getSUnit()->print(dbgs(), G);
|
|
if (SuccDep.isArtificial())
|
|
dbgs() << " *";
|
|
dbgs() << ": Latency=" << SuccDep.getLatency();
|
|
if (SuccDep.isAssignedRegDep())
|
|
dbgs() << " Reg=" << PrintReg(SuccDep.getReg(), G->TRI);
|
|
dbgs() << "\n";
|
|
}
|
|
}
|
|
if (Succs.size() != 0) {
|
|
dbgs() << " Successors:\n";
|
|
for (const SDep &SuccDep : Succs) {
|
|
dbgs() << " ";
|
|
switch (SuccDep.getKind()) {
|
|
case SDep::Data: dbgs() << "data "; break;
|
|
case SDep::Anti: dbgs() << "anti "; break;
|
|
case SDep::Output: dbgs() << "out "; break;
|
|
case SDep::Order: dbgs() << "ord "; break;
|
|
}
|
|
SuccDep.getSUnit()->print(dbgs(), G);
|
|
if (SuccDep.isArtificial())
|
|
dbgs() << " *";
|
|
dbgs() << ": Latency=" << SuccDep.getLatency();
|
|
if (SuccDep.isAssignedRegDep())
|
|
dbgs() << " Reg=" << PrintReg(SuccDep.getReg(), G->TRI);
|
|
dbgs() << "\n";
|
|
}
|
|
}
|
|
}
|
|
#endif
|
|
|
|
#ifndef NDEBUG
|
|
unsigned ScheduleDAG::VerifyScheduledDAG(bool isBottomUp) {
|
|
bool AnyNotSched = false;
|
|
unsigned DeadNodes = 0;
|
|
for (const SUnit &SUnit : SUnits) {
|
|
if (!SUnit.isScheduled) {
|
|
if (SUnit.NumPreds == 0 && SUnit.NumSuccs == 0) {
|
|
++DeadNodes;
|
|
continue;
|
|
}
|
|
if (!AnyNotSched)
|
|
dbgs() << "*** Scheduling failed! ***\n";
|
|
SUnit.dump(this);
|
|
dbgs() << "has not been scheduled!\n";
|
|
AnyNotSched = true;
|
|
}
|
|
if (SUnit.isScheduled &&
|
|
(isBottomUp ? SUnit.getHeight() : SUnit.getDepth()) >
|
|
unsigned(std::numeric_limits<int>::max())) {
|
|
if (!AnyNotSched)
|
|
dbgs() << "*** Scheduling failed! ***\n";
|
|
SUnit.dump(this);
|
|
dbgs() << "has an unexpected "
|
|
<< (isBottomUp ? "Height" : "Depth") << " value!\n";
|
|
AnyNotSched = true;
|
|
}
|
|
if (isBottomUp) {
|
|
if (SUnit.NumSuccsLeft != 0) {
|
|
if (!AnyNotSched)
|
|
dbgs() << "*** Scheduling failed! ***\n";
|
|
SUnit.dump(this);
|
|
dbgs() << "has successors left!\n";
|
|
AnyNotSched = true;
|
|
}
|
|
} else {
|
|
if (SUnit.NumPredsLeft != 0) {
|
|
if (!AnyNotSched)
|
|
dbgs() << "*** Scheduling failed! ***\n";
|
|
SUnit.dump(this);
|
|
dbgs() << "has predecessors left!\n";
|
|
AnyNotSched = true;
|
|
}
|
|
}
|
|
}
|
|
assert(!AnyNotSched);
|
|
return SUnits.size() - DeadNodes;
|
|
}
|
|
#endif
|
|
|
|
void ScheduleDAGTopologicalSort::InitDAGTopologicalSorting() {
|
|
// The idea of the algorithm is taken from
|
|
// "Online algorithms for managing the topological order of
|
|
// a directed acyclic graph" by David J. Pearce and Paul H.J. Kelly
|
|
// This is the MNR algorithm, which was first introduced by
|
|
// A. Marchetti-Spaccamela, U. Nanni and H. Rohnert in
|
|
// "Maintaining a topological order under edge insertions".
|
|
//
|
|
// Short description of the algorithm:
|
|
//
|
|
// Topological ordering, ord, of a DAG maps each node to a topological
|
|
// index so that for all edges X->Y it is the case that ord(X) < ord(Y).
|
|
//
|
|
// This means that if there is a path from the node X to the node Z,
|
|
// then ord(X) < ord(Z).
|
|
//
|
|
// This property can be used to check for reachability of nodes:
|
|
// if Z is reachable from X, then an insertion of the edge Z->X would
|
|
// create a cycle.
|
|
//
|
|
// The algorithm first computes a topological ordering for the DAG by
|
|
// initializing the Index2Node and Node2Index arrays and then tries to keep
|
|
// the ordering up-to-date after edge insertions by reordering the DAG.
|
|
//
|
|
// On insertion of the edge X->Y, the algorithm first marks by calling DFS
|
|
// the nodes reachable from Y, and then shifts them using Shift to lie
|
|
// immediately after X in Index2Node.
|
|
unsigned DAGSize = SUnits.size();
|
|
std::vector<SUnit*> WorkList;
|
|
WorkList.reserve(DAGSize);
|
|
|
|
Index2Node.resize(DAGSize);
|
|
Node2Index.resize(DAGSize);
|
|
|
|
// Initialize the data structures.
|
|
if (ExitSU)
|
|
WorkList.push_back(ExitSU);
|
|
for (SUnit &SU : SUnits) {
|
|
int NodeNum = SU.NodeNum;
|
|
unsigned Degree = SU.Succs.size();
|
|
// Temporarily use the Node2Index array as scratch space for degree counts.
|
|
Node2Index[NodeNum] = Degree;
|
|
|
|
// Is it a node without dependencies?
|
|
if (Degree == 0) {
|
|
assert(SU.Succs.empty() && "SUnit should have no successors");
|
|
// Collect leaf nodes.
|
|
WorkList.push_back(&SU);
|
|
}
|
|
}
|
|
|
|
int Id = DAGSize;
|
|
while (!WorkList.empty()) {
|
|
SUnit *SU = WorkList.back();
|
|
WorkList.pop_back();
|
|
if (SU->NodeNum < DAGSize)
|
|
Allocate(SU->NodeNum, --Id);
|
|
for (const SDep &PredDep : SU->Preds) {
|
|
SUnit *SU = PredDep.getSUnit();
|
|
if (SU->NodeNum < DAGSize && !--Node2Index[SU->NodeNum])
|
|
// If all dependencies of the node are processed already,
|
|
// then the node can be computed now.
|
|
WorkList.push_back(SU);
|
|
}
|
|
}
|
|
|
|
Visited.resize(DAGSize);
|
|
|
|
#ifndef NDEBUG
|
|
// Check correctness of the ordering
|
|
for (SUnit &SU : SUnits) {
|
|
for (const SDep &PD : SU.Preds) {
|
|
assert(Node2Index[SU.NodeNum] > Node2Index[PD.getSUnit()->NodeNum] &&
|
|
"Wrong topological sorting");
|
|
}
|
|
}
|
|
#endif
|
|
}
|
|
|
|
void ScheduleDAGTopologicalSort::AddPred(SUnit *Y, SUnit *X) {
|
|
int UpperBound, LowerBound;
|
|
LowerBound = Node2Index[Y->NodeNum];
|
|
UpperBound = Node2Index[X->NodeNum];
|
|
bool HasLoop = false;
|
|
// Is Ord(X) < Ord(Y) ?
|
|
if (LowerBound < UpperBound) {
|
|
// Update the topological order.
|
|
Visited.reset();
|
|
DFS(Y, UpperBound, HasLoop);
|
|
assert(!HasLoop && "Inserted edge creates a loop!");
|
|
// Recompute topological indexes.
|
|
Shift(Visited, LowerBound, UpperBound);
|
|
}
|
|
}
|
|
|
|
void ScheduleDAGTopologicalSort::RemovePred(SUnit *M, SUnit *N) {
|
|
// InitDAGTopologicalSorting();
|
|
}
|
|
|
|
void ScheduleDAGTopologicalSort::DFS(const SUnit *SU, int UpperBound,
|
|
bool &HasLoop) {
|
|
std::vector<const SUnit*> WorkList;
|
|
WorkList.reserve(SUnits.size());
|
|
|
|
WorkList.push_back(SU);
|
|
do {
|
|
SU = WorkList.back();
|
|
WorkList.pop_back();
|
|
Visited.set(SU->NodeNum);
|
|
for (const SDep &SuccDep
|
|
: make_range(SU->Succs.rbegin(), SU->Succs.rend())) {
|
|
unsigned s = SuccDep.getSUnit()->NodeNum;
|
|
// Edges to non-SUnits are allowed but ignored (e.g. ExitSU).
|
|
if (s >= Node2Index.size())
|
|
continue;
|
|
if (Node2Index[s] == UpperBound) {
|
|
HasLoop = true;
|
|
return;
|
|
}
|
|
// Visit successors if not already and in affected region.
|
|
if (!Visited.test(s) && Node2Index[s] < UpperBound) {
|
|
WorkList.push_back(SuccDep.getSUnit());
|
|
}
|
|
}
|
|
} while (!WorkList.empty());
|
|
}
|
|
|
|
std::vector<int> ScheduleDAGTopologicalSort::GetSubGraph(const SUnit &StartSU,
|
|
const SUnit &TargetSU,
|
|
bool &Success) {
|
|
std::vector<const SUnit*> WorkList;
|
|
int LowerBound = Node2Index[StartSU.NodeNum];
|
|
int UpperBound = Node2Index[TargetSU.NodeNum];
|
|
bool Found = false;
|
|
BitVector VisitedBack;
|
|
std::vector<int> Nodes;
|
|
|
|
if (LowerBound > UpperBound) {
|
|
Success = false;
|
|
return Nodes;
|
|
}
|
|
|
|
WorkList.reserve(SUnits.size());
|
|
Visited.reset();
|
|
|
|
// Starting from StartSU, visit all successors up
|
|
// to UpperBound.
|
|
WorkList.push_back(&StartSU);
|
|
do {
|
|
const SUnit *SU = WorkList.back();
|
|
WorkList.pop_back();
|
|
for (int I = SU->Succs.size()-1; I >= 0; --I) {
|
|
const SUnit *Succ = SU->Succs[I].getSUnit();
|
|
unsigned s = Succ->NodeNum;
|
|
// Edges to non-SUnits are allowed but ignored (e.g. ExitSU).
|
|
if (Succ->isBoundaryNode())
|
|
continue;
|
|
if (Node2Index[s] == UpperBound) {
|
|
Found = true;
|
|
continue;
|
|
}
|
|
// Visit successors if not already and in affected region.
|
|
if (!Visited.test(s) && Node2Index[s] < UpperBound) {
|
|
Visited.set(s);
|
|
WorkList.push_back(Succ);
|
|
}
|
|
}
|
|
} while (!WorkList.empty());
|
|
|
|
if (!Found) {
|
|
Success = false;
|
|
return Nodes;
|
|
}
|
|
|
|
WorkList.clear();
|
|
VisitedBack.resize(SUnits.size());
|
|
Found = false;
|
|
|
|
// Starting from TargetSU, visit all predecessors up
|
|
// to LowerBound. SUs that are visited by the two
|
|
// passes are added to Nodes.
|
|
WorkList.push_back(&TargetSU);
|
|
do {
|
|
const SUnit *SU = WorkList.back();
|
|
WorkList.pop_back();
|
|
for (int I = SU->Preds.size()-1; I >= 0; --I) {
|
|
const SUnit *Pred = SU->Preds[I].getSUnit();
|
|
unsigned s = Pred->NodeNum;
|
|
// Edges to non-SUnits are allowed but ignored (e.g. EntrySU).
|
|
if (Pred->isBoundaryNode())
|
|
continue;
|
|
if (Node2Index[s] == LowerBound) {
|
|
Found = true;
|
|
continue;
|
|
}
|
|
if (!VisitedBack.test(s) && Visited.test(s)) {
|
|
VisitedBack.set(s);
|
|
WorkList.push_back(Pred);
|
|
Nodes.push_back(s);
|
|
}
|
|
}
|
|
} while (!WorkList.empty());
|
|
|
|
assert(Found && "Error in SUnit Graph!");
|
|
Success = true;
|
|
return Nodes;
|
|
}
|
|
|
|
void ScheduleDAGTopologicalSort::Shift(BitVector& Visited, int LowerBound,
|
|
int UpperBound) {
|
|
std::vector<int> L;
|
|
int shift = 0;
|
|
int i;
|
|
|
|
for (i = LowerBound; i <= UpperBound; ++i) {
|
|
// w is node at topological index i.
|
|
int w = Index2Node[i];
|
|
if (Visited.test(w)) {
|
|
// Unmark.
|
|
Visited.reset(w);
|
|
L.push_back(w);
|
|
shift = shift + 1;
|
|
} else {
|
|
Allocate(w, i - shift);
|
|
}
|
|
}
|
|
|
|
for (unsigned LI : L) {
|
|
Allocate(LI, i - shift);
|
|
i = i + 1;
|
|
}
|
|
}
|
|
|
|
bool ScheduleDAGTopologicalSort::WillCreateCycle(SUnit *TargetSU, SUnit *SU) {
|
|
// Is SU reachable from TargetSU via successor edges?
|
|
if (IsReachable(SU, TargetSU))
|
|
return true;
|
|
for (const SDep &PredDep : TargetSU->Preds)
|
|
if (PredDep.isAssignedRegDep() &&
|
|
IsReachable(SU, PredDep.getSUnit()))
|
|
return true;
|
|
return false;
|
|
}
|
|
|
|
bool ScheduleDAGTopologicalSort::IsReachable(const SUnit *SU,
|
|
const SUnit *TargetSU) {
|
|
// If insertion of the edge SU->TargetSU would create a cycle
|
|
// then there is a path from TargetSU to SU.
|
|
int UpperBound, LowerBound;
|
|
LowerBound = Node2Index[TargetSU->NodeNum];
|
|
UpperBound = Node2Index[SU->NodeNum];
|
|
bool HasLoop = false;
|
|
// Is Ord(TargetSU) < Ord(SU) ?
|
|
if (LowerBound < UpperBound) {
|
|
Visited.reset();
|
|
// There may be a path from TargetSU to SU. Check for it.
|
|
DFS(TargetSU, UpperBound, HasLoop);
|
|
}
|
|
return HasLoop;
|
|
}
|
|
|
|
void ScheduleDAGTopologicalSort::Allocate(int n, int index) {
|
|
Node2Index[n] = index;
|
|
Index2Node[index] = n;
|
|
}
|
|
|
|
ScheduleDAGTopologicalSort::
|
|
ScheduleDAGTopologicalSort(std::vector<SUnit> &sunits, SUnit *exitsu)
|
|
: SUnits(sunits), ExitSU(exitsu) {}
|
|
|
|
ScheduleHazardRecognizer::~ScheduleHazardRecognizer() = default;
|