diff options
Diffstat (limited to 'lib/CodeGen/ScheduleDAG.cpp')
| -rw-r--r-- | lib/CodeGen/ScheduleDAG.cpp | 442 |
1 files changed, 243 insertions, 199 deletions
diff --git a/lib/CodeGen/ScheduleDAG.cpp b/lib/CodeGen/ScheduleDAG.cpp index 427d95268c74..dc72ac073258 100644 --- a/lib/CodeGen/ScheduleDAG.cpp +++ b/lib/CodeGen/ScheduleDAG.cpp @@ -1,4 +1,4 @@ -//===---- ScheduleDAG.cpp - Implement the ScheduleDAG class ---------------===// +//===- ScheduleDAG.cpp - Implement the ScheduleDAG class ------------------===// // // The LLVM Compiler Infrastructure // @@ -7,22 +7,32 @@ // //===----------------------------------------------------------------------===// // -// This implements the ScheduleDAG class, which is a base class used by -// scheduling implementation classes. +/// \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/TargetMachine.h" #include "llvm/Target/TargetRegisterInfo.h" #include "llvm/Target/TargetSubtargetInfo.h" -#include <climits> +#include <algorithm> +#include <cassert> +#include <iterator> +#include <limits> +#include <utility> +#include <vector> + using namespace llvm; #define DEBUG_TYPE "pre-RA-sched" @@ -33,58 +43,52 @@ static cl::opt<bool> StressSchedOpt( cl::desc("Stress test instruction scheduling")); #endif -void SchedulingPriorityQueue::anchor() { } +void SchedulingPriorityQueue::anchor() {} ScheduleDAG::ScheduleDAG(MachineFunction &mf) : TM(mf.getTarget()), TII(mf.getSubtarget().getInstrInfo()), TRI(mf.getSubtarget().getRegisterInfo()), MF(mf), - MRI(mf.getRegInfo()), EntrySU(), ExitSU() { + MRI(mf.getRegInfo()) { #ifndef NDEBUG StressSched = StressSchedOpt; #endif } -ScheduleDAG::~ScheduleDAG() {} +ScheduleDAG::~ScheduleDAG() = default; -/// Clear the DAG state (e.g. between scheduling regions). void ScheduleDAG::clearDAG() { SUnits.clear(); EntrySU = SUnit(); ExitSU = SUnit(); } -/// getInstrDesc helper to handle SDNodes. const MCInstrDesc *ScheduleDAG::getNodeDesc(const SDNode *Node) const { if (!Node || !Node->isMachineOpcode()) return nullptr; return &TII->get(Node->getMachineOpcode()); } -/// 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. bool SUnit::addPred(const SDep &D, bool Required) { // If this node already has this dependence, don't add a redundant one. - for (SmallVectorImpl<SDep>::iterator I = Preds.begin(), E = Preds.end(); - I != E; ++I) { + 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 && I->getSUnit() == D.getSUnit()) + if (!Required && PredDep.getSUnit() == D.getSUnit()) return false; - if (I->overlaps(D)) { - // Extend the latency if needed. Equivalent to removePred(I) + addPred(D). - if (I->getLatency() < D.getLatency()) { - SUnit *PredSU = I->getSUnit(); + 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 = *I; + SDep ForwardD = PredDep; ForwardD.setSUnit(this); - for (SmallVectorImpl<SDep>::iterator II = PredSU->Succs.begin(), - EE = PredSU->Succs.end(); II != EE; ++II) { - if (*II == ForwardD) { - II->setLatency(D.getLatency()); + for (SDep &SuccDep : PredSU->Succs) { + if (SuccDep == ForwardD) { + SuccDep.setLatency(D.getLatency()); break; } } - I->setLatency(D.getLatency()); + PredDep.setLatency(D.getLatency()); } return false; } @@ -95,8 +99,10 @@ bool SUnit::addPred(const SDep &D, bool Required) { SUnit *N = D.getSUnit(); // Update the bookkeeping. if (D.getKind() == SDep::Data) { - assert(NumPreds < UINT_MAX && "NumPreds will overflow!"); - assert(N->NumSuccs < UINT_MAX && "NumSuccs will overflow!"); + assert(NumPreds < std::numeric_limits<unsigned>::max() && + "NumPreds will overflow!"); + assert(N->NumSuccs < std::numeric_limits<unsigned>::max() && + "NumSuccs will overflow!"); ++NumPreds; ++N->NumSuccs; } @@ -105,7 +111,8 @@ bool SUnit::addPred(const SDep &D, bool Required) { ++WeakPredsLeft; } else { - assert(NumPredsLeft < UINT_MAX && "NumPredsLeft will overflow!"); + assert(NumPredsLeft < std::numeric_limits<unsigned>::max() && + "NumPredsLeft will overflow!"); ++NumPredsLeft; } } @@ -114,7 +121,8 @@ bool SUnit::addPred(const SDep &D, bool Required) { ++N->WeakSuccsLeft; } else { - assert(N->NumSuccsLeft < UINT_MAX && "NumSuccsLeft will overflow!"); + assert(N->NumSuccsLeft < std::numeric_limits<unsigned>::max() && + "NumSuccsLeft will overflow!"); ++N->NumSuccsLeft; } } @@ -127,51 +135,46 @@ bool SUnit::addPred(const SDep &D, bool Required) { return 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 SUnit::removePred(const SDep &D) { // Find the matching predecessor. - for (SmallVectorImpl<SDep>::iterator I = Preds.begin(), E = Preds.end(); - I != E; ++I) - if (*I == D) { - // Find the corresponding successor in N. - SDep P = D; - P.setSUnit(this); - SUnit *N = D.getSUnit(); - SmallVectorImpl<SDep>::iterator Succ = 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(); - } - return; + 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() { @@ -181,9 +184,8 @@ void SUnit::setDepthDirty() { do { SUnit *SU = WorkList.pop_back_val(); SU->isDepthCurrent = false; - for (SUnit::const_succ_iterator I = SU->Succs.begin(), - E = SU->Succs.end(); I != E; ++I) { - SUnit *SuccSU = I->getSUnit(); + for (SDep &SuccDep : SU->Succs) { + SUnit *SuccSU = SuccDep.getSUnit(); if (SuccSU->isDepthCurrent) WorkList.push_back(SuccSU); } @@ -197,18 +199,14 @@ void SUnit::setHeightDirty() { do { SUnit *SU = WorkList.pop_back_val(); SU->isHeightCurrent = false; - for (SUnit::const_pred_iterator I = SU->Preds.begin(), - E = SU->Preds.end(); I != E; ++I) { - SUnit *PredSU = I->getSUnit(); + for (SDep &PredDep : SU->Preds) { + SUnit *PredSU = PredDep.getSUnit(); if (PredSU->isHeightCurrent) WorkList.push_back(PredSU); } } while (!WorkList.empty()); } -/// setDepthToAtLeast - Update this node's successors to reflect the -/// fact that this node's depth just increased. -/// void SUnit::setDepthToAtLeast(unsigned NewDepth) { if (NewDepth <= getDepth()) return; @@ -217,9 +215,6 @@ void SUnit::setDepthToAtLeast(unsigned NewDepth) { isDepthCurrent = true; } -/// setHeightToAtLeast - Update this node's predecessors to reflect the -/// fact that this node's height just increased. -/// void SUnit::setHeightToAtLeast(unsigned NewHeight) { if (NewHeight <= getHeight()) return; @@ -228,8 +223,7 @@ void SUnit::setHeightToAtLeast(unsigned NewHeight) { isHeightCurrent = true; } -/// ComputeDepth - Calculate the maximal path from the node to the exit. -/// +/// Calculates the maximal path from the node to the exit. void SUnit::ComputeDepth() { SmallVector<SUnit*, 8> WorkList; WorkList.push_back(this); @@ -238,12 +232,11 @@ void SUnit::ComputeDepth() { bool Done = true; unsigned MaxPredDepth = 0; - for (SUnit::const_pred_iterator I = Cur->Preds.begin(), - E = Cur->Preds.end(); I != E; ++I) { - SUnit *PredSU = I->getSUnit(); + for (const SDep &PredDep : Cur->Preds) { + SUnit *PredSU = PredDep.getSUnit(); if (PredSU->isDepthCurrent) MaxPredDepth = std::max(MaxPredDepth, - PredSU->Depth + I->getLatency()); + PredSU->Depth + PredDep.getLatency()); else { Done = false; WorkList.push_back(PredSU); @@ -261,8 +254,7 @@ void SUnit::ComputeDepth() { } while (!WorkList.empty()); } -/// ComputeHeight - Calculate the maximal path from the node to the entry. -/// +/// Calculates the maximal path from the node to the entry. void SUnit::ComputeHeight() { SmallVector<SUnit*, 8> WorkList; WorkList.push_back(this); @@ -271,12 +263,11 @@ void SUnit::ComputeHeight() { bool Done = true; unsigned MaxSuccHeight = 0; - for (SUnit::const_succ_iterator I = Cur->Succs.begin(), - E = Cur->Succs.end(); I != E; ++I) { - SUnit *SuccSU = I->getSUnit(); + for (const SDep &SuccDep : Cur->Succs) { + SUnit *SuccSU = SuccDep.getSUnit(); if (SuccSU->isHeightCurrent) MaxSuccHeight = std::max(MaxSuccHeight, - SuccSU->Height + I->getLatency()); + SuccSU->Height + SuccDep.getLatency()); else { Done = false; WorkList.push_back(SuccSU); @@ -310,6 +301,7 @@ void SUnit::biasCriticalPath() { } #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"; @@ -319,15 +311,13 @@ void SUnit::print(raw_ostream &OS, const ScheduleDAG *DAG) const { OS << "SU(" << NodeNum << ")"; } -/// SUnit - Scheduling unit. It's an wrapper around either a single SDNode or -/// a group of nodes flagged together. -void SUnit::dump(const ScheduleDAG *G) const { +LLVM_DUMP_METHOD void SUnit::dump(const ScheduleDAG *G) const { print(dbgs(), G); dbgs() << ": "; G->dumpNode(this); } -void SUnit::dumpAll(const ScheduleDAG *G) const { +LLVM_DUMP_METHOD void SUnit::dumpAll(const ScheduleDAG *G) const { dump(G); dbgs() << " # preds left : " << NumPredsLeft << "\n"; @@ -343,41 +333,39 @@ void SUnit::dumpAll(const ScheduleDAG *G) const { if (Preds.size() != 0) { dbgs() << " Predecessors:\n"; - for (SUnit::const_succ_iterator I = Preds.begin(), E = Preds.end(); - I != E; ++I) { + for (const SDep &SuccDep : Preds) { dbgs() << " "; - switch (I->getKind()) { + 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; } - I->getSUnit()->print(dbgs(), G); - if (I->isArtificial()) + SuccDep.getSUnit()->print(dbgs(), G); + if (SuccDep.isArtificial()) dbgs() << " *"; - dbgs() << ": Latency=" << I->getLatency(); - if (I->isAssignedRegDep()) - dbgs() << " Reg=" << PrintReg(I->getReg(), G->TRI); + dbgs() << ": Latency=" << SuccDep.getLatency(); + if (SuccDep.isAssignedRegDep()) + dbgs() << " Reg=" << PrintReg(SuccDep.getReg(), G->TRI); dbgs() << "\n"; } } if (Succs.size() != 0) { dbgs() << " Successors:\n"; - for (SUnit::const_succ_iterator I = Succs.begin(), E = Succs.end(); - I != E; ++I) { + for (const SDep &SuccDep : Succs) { dbgs() << " "; - switch (I->getKind()) { + 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; } - I->getSUnit()->print(dbgs(), G); - if (I->isArtificial()) + SuccDep.getSUnit()->print(dbgs(), G); + if (SuccDep.isArtificial()) dbgs() << " *"; - dbgs() << ": Latency=" << I->getLatency(); - if (I->isAssignedRegDep()) - dbgs() << " Reg=" << PrintReg(I->getReg(), G->TRI); + dbgs() << ": Latency=" << SuccDep.getLatency(); + if (SuccDep.isAssignedRegDep()) + dbgs() << " Reg=" << PrintReg(SuccDep.getReg(), G->TRI); dbgs() << "\n"; } } @@ -385,47 +373,44 @@ void SUnit::dumpAll(const ScheduleDAG *G) const { #endif #ifndef NDEBUG -/// VerifyScheduledDAG - Verify that all SUnits were scheduled and that -/// their state is consistent. Return the number of scheduled nodes. -/// unsigned ScheduleDAG::VerifyScheduledDAG(bool isBottomUp) { bool AnyNotSched = false; unsigned DeadNodes = 0; - for (unsigned i = 0, e = SUnits.size(); i != e; ++i) { - if (!SUnits[i].isScheduled) { - if (SUnits[i].NumPreds == 0 && SUnits[i].NumSuccs == 0) { + for (const SUnit &SUnit : SUnits) { + if (!SUnit.isScheduled) { + if (SUnit.NumPreds == 0 && SUnit.NumSuccs == 0) { ++DeadNodes; continue; } if (!AnyNotSched) dbgs() << "*** Scheduling failed! ***\n"; - SUnits[i].dump(this); + SUnit.dump(this); dbgs() << "has not been scheduled!\n"; AnyNotSched = true; } - if (SUnits[i].isScheduled && - (isBottomUp ? SUnits[i].getHeight() : SUnits[i].getDepth()) > - unsigned(INT_MAX)) { + if (SUnit.isScheduled && + (isBottomUp ? SUnit.getHeight() : SUnit.getDepth()) > + unsigned(std::numeric_limits<int>::max())) { if (!AnyNotSched) dbgs() << "*** Scheduling failed! ***\n"; - SUnits[i].dump(this); + SUnit.dump(this); dbgs() << "has an unexpected " << (isBottomUp ? "Height" : "Depth") << " value!\n"; AnyNotSched = true; } if (isBottomUp) { - if (SUnits[i].NumSuccsLeft != 0) { + if (SUnit.NumSuccsLeft != 0) { if (!AnyNotSched) dbgs() << "*** Scheduling failed! ***\n"; - SUnits[i].dump(this); + SUnit.dump(this); dbgs() << "has successors left!\n"; AnyNotSched = true; } } else { - if (SUnits[i].NumPredsLeft != 0) { + if (SUnit.NumPredsLeft != 0) { if (!AnyNotSched) dbgs() << "*** Scheduling failed! ***\n"; - SUnits[i].dump(this); + SUnit.dump(this); dbgs() << "has predecessors left!\n"; AnyNotSched = true; } @@ -436,36 +421,33 @@ unsigned ScheduleDAG::VerifyScheduledDAG(bool isBottomUp) { } #endif -/// InitDAGTopologicalSorting - create the initial topological -/// ordering from the DAG to be scheduled. -/// -/// 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. 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); @@ -476,18 +458,17 @@ void ScheduleDAGTopologicalSort::InitDAGTopologicalSorting() { // Initialize the data structures. if (ExitSU) WorkList.push_back(ExitSU); - for (unsigned i = 0, e = DAGSize; i != e; ++i) { - SUnit *SU = &SUnits[i]; - int NodeNum = SU->NodeNum; - unsigned Degree = SU->Succs.size(); + 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"); + assert(SU.Succs.empty() && "SUnit should have no successors"); // Collect leaf nodes. - WorkList.push_back(SU); + WorkList.push_back(&SU); } } @@ -497,9 +478,8 @@ void ScheduleDAGTopologicalSort::InitDAGTopologicalSorting() { WorkList.pop_back(); if (SU->NodeNum < DAGSize) Allocate(SU->NodeNum, --Id); - for (SUnit::const_pred_iterator I = SU->Preds.begin(), E = SU->Preds.end(); - I != E; ++I) { - SUnit *SU = I->getSUnit(); + 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. @@ -511,19 +491,15 @@ void ScheduleDAGTopologicalSort::InitDAGTopologicalSorting() { #ifndef NDEBUG // Check correctness of the ordering - for (unsigned i = 0, e = DAGSize; i != e; ++i) { - SUnit *SU = &SUnits[i]; - for (SUnit::const_pred_iterator I = SU->Preds.begin(), E = SU->Preds.end(); - I != E; ++I) { - assert(Node2Index[SU->NodeNum] > Node2Index[I->getSUnit()->NodeNum] && + for (SUnit &SU : SUnits) { + for (const SDep &PD : SU.Preds) { + assert(Node2Index[SU.NodeNum] > Node2Index[PD.getSUnit()->NodeNum] && "Wrong topological sorting"); } } #endif } -/// AddPred - Updates the topological ordering to accommodate an edge -/// to be added from SUnit X to SUnit Y. void ScheduleDAGTopologicalSort::AddPred(SUnit *Y, SUnit *X) { int UpperBound, LowerBound; LowerBound = Node2Index[Y->NodeNum]; @@ -540,16 +516,10 @@ void ScheduleDAGTopologicalSort::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 ScheduleDAGTopologicalSort::RemovePred(SUnit *M, SUnit *N) { // InitDAGTopologicalSorting(); } -/// DFS - Make a DFS traversal to mark all nodes reachable from SU and mark -/// all nodes affected by the edge insertion. These nodes will later get new -/// topological indexes by means of the Shift method. void ScheduleDAGTopologicalSort::DFS(const SUnit *SU, int UpperBound, bool &HasLoop) { std::vector<const SUnit*> WorkList; @@ -560,8 +530,9 @@ void ScheduleDAGTopologicalSort::DFS(const SUnit *SU, int UpperBound, SU = WorkList.back(); WorkList.pop_back(); Visited.set(SU->NodeNum); - for (int I = SU->Succs.size()-1; I >= 0; --I) { - unsigned s = SU->Succs[I].getSUnit()->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; @@ -571,14 +542,93 @@ void ScheduleDAGTopologicalSort::DFS(const SUnit *SU, int UpperBound, } // Visit successors if not already and in affected region. if (!Visited.test(s) && Node2Index[s] < UpperBound) { - WorkList.push_back(SU->Succs[I].getSUnit()); + WorkList.push_back(SuccDep.getSUnit()); } } } while (!WorkList.empty()); } -/// Shift - Renumber the nodes so that the topological ordering is -/// preserved. +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; @@ -598,28 +648,23 @@ void ScheduleDAGTopologicalSort::Shift(BitVector& Visited, int LowerBound, } } - for (unsigned j = 0; j < L.size(); ++j) { - Allocate(L[j], i - shift); + for (unsigned LI : L) { + Allocate(LI, i - shift); i = i + 1; } } - -/// WillCreateCycle - Returns true if adding an edge to TargetSU from SU will -/// create a cycle. If so, it is not safe to call AddPred(TargetSU, SU). bool ScheduleDAGTopologicalSort::WillCreateCycle(SUnit *TargetSU, SUnit *SU) { // Is SU reachable from TargetSU via successor edges? if (IsReachable(SU, TargetSU)) return true; - for (SUnit::pred_iterator - I = TargetSU->Preds.begin(), E = TargetSU->Preds.end(); I != E; ++I) - if (I->isAssignedRegDep() && - IsReachable(SU, I->getSUnit())) + for (const SDep &PredDep : TargetSU->Preds) + if (PredDep.isAssignedRegDep() && + IsReachable(SU, PredDep.getSUnit())) return true; return false; } -/// IsReachable - Checks if SU is reachable from TargetSU. bool ScheduleDAGTopologicalSort::IsReachable(const SUnit *SU, const SUnit *TargetSU) { // If insertion of the edge SU->TargetSU would create a cycle @@ -637,7 +682,6 @@ bool ScheduleDAGTopologicalSort::IsReachable(const SUnit *SU, return HasLoop; } -/// Allocate - assign the topological index to the node n. void ScheduleDAGTopologicalSort::Allocate(int n, int index) { Node2Index[n] = index; Index2Node[index] = n; @@ -647,4 +691,4 @@ ScheduleDAGTopologicalSort:: ScheduleDAGTopologicalSort(std::vector<SUnit> &sunits, SUnit *exitsu) : SUnits(sunits), ExitSU(exitsu) {} -ScheduleHazardRecognizer::~ScheduleHazardRecognizer() {} +ScheduleHazardRecognizer::~ScheduleHazardRecognizer() = default; |