Changes in directory llvm/lib/CodeGen/SelectionDAG:
ScheduleDAGList.cpp updated: 1.6 -> 1.7 --- Log message: - Fixed some priority calculation bugs that were causing bug 478: http://llvm.cs.uiuc.edu/PR478 . Among them: a predecessor appearing more than once in the operand list was counted as multiple predecessor; priority1 should be updated during scheduling; CycleBound was updated after the node is inserted into priority queue; one of the tie breaking condition was flipped. - Take into consideration of two address opcodes. If a predecessor is a def&use operand, it should have a higher priority. - Scheduler should also favor floaters, i.e. nodes that do not have real predecessors such as MOV32ri. - The scheduling fixes / tweaks fixed bug 478: http://llvm.cs.uiuc.edu/PR478 : .text .align 4 .globl _f _f: movl 4(%esp), %eax movl 8(%esp), %ecx movl %eax, %edx imull %ecx, %edx imull %eax, %eax imull %ecx, %ecx addl %eax, %ecx leal (%ecx,%edx,2), %eax ret It is also a slight performance win (1% - 3%) for most tests. --- Diffs of the changes: (+98 -64) ScheduleDAGList.cpp | 162 +++++++++++++++++++++++++++++++--------------------- 1 files changed, 98 insertions(+), 64 deletions(-) Index: llvm/lib/CodeGen/SelectionDAG/ScheduleDAGList.cpp diff -u llvm/lib/CodeGen/SelectionDAG/ScheduleDAGList.cpp:1.6 llvm/lib/CodeGen/SelectionDAG/ScheduleDAGList.cpp:1.7 --- llvm/lib/CodeGen/SelectionDAG/ScheduleDAGList.cpp:1.6 Wed Feb 1 18:38:08 2006 +++ llvm/lib/CodeGen/SelectionDAG/ScheduleDAGList.cpp Thu Mar 2 15:38:29 2006 @@ -21,8 +21,9 @@ #include "llvm/Support/Debug.h" #include <climits> #include <iostream> -#include <memory> #include <queue> +#include <set> +#include <vector> using namespace llvm; namespace { @@ -32,14 +33,17 @@ struct SUnit { SDNode *Node; // Representative node. std::vector<SDNode*> FlaggedNodes; // All nodes flagged to Node. - std::vector<SUnit*> Preds; // All real predecessors. - std::vector<SUnit*> ChainPreds; // All chain predecessors. - std::vector<SUnit*> Succs; // All real successors. - std::vector<SUnit*> ChainSuccs; // All chain successors. + std::set<SUnit*> Preds; // All real predecessors. + std::set<SUnit*> ChainPreds; // All chain predecessors. + std::set<SUnit*> Succs; // All real successors. + std::set<SUnit*> ChainSuccs; // All chain successors. int NumPredsLeft; // # of preds not scheduled. int NumSuccsLeft; // # of succs not scheduled. + int NumChainPredsLeft; // # of chain preds not scheduled. + int NumChainSuccsLeft; // # of chain succs not scheduled. int Priority1; // Scheduling priority 1. int Priority2; // Scheduling priority 2. + bool isDefNUseOperand; // Is a def&use operand. unsigned Latency; // Node latency. unsigned CycleBound; // Upper/lower cycle to be scheduled at. unsigned Slot; // Cycle node is scheduled at. @@ -47,8 +51,9 @@ SUnit(SDNode *node) : Node(node), NumPredsLeft(0), NumSuccsLeft(0), - Priority1(INT_MIN), Priority2(INT_MIN), Latency(0), - CycleBound(0), Slot(0), Next(NULL) {} + NumChainPredsLeft(0), NumChainSuccsLeft(0), + Priority1(INT_MIN), Priority2(INT_MIN), isDefNUseOperand(false), + Latency(0), CycleBound(0), Slot(0), Next(NULL) {} void dump(const SelectionDAG *G, bool All=true) const; }; @@ -66,37 +71,43 @@ } if (All) { - std::cerr << "# preds left : " << NumPredsLeft << "\n"; - std::cerr << "# succs left : " << NumSuccsLeft << "\n"; - std::cerr << "Latency : " << Latency << "\n"; - std::cerr << "Priority : " << Priority1 << " , " << Priority2 << "\n"; + std::cerr << "# preds left : " << NumPredsLeft << "\n"; + std::cerr << "# succs left : " << NumSuccsLeft << "\n"; + std::cerr << "# chain preds left : " << NumChainPredsLeft << "\n"; + std::cerr << "# chain succs left : " << NumChainSuccsLeft << "\n"; + std::cerr << "Latency : " << Latency << "\n"; + std::cerr << "Priority : " << Priority1 << " , " << Priority2 << "\n"; if (Preds.size() != 0) { std::cerr << "Predecessors :\n"; - for (unsigned i = 0, e = Preds.size(); i != e; i++) { + for (std::set<SUnit*>::iterator I = Preds.begin(), + E = Preds.end(); I != E; ++I) { std::cerr << " "; - Preds[i]->dump(G, false); + (*I)->dump(G, false); } } if (ChainPreds.size() != 0) { std::cerr << "Chained Preds :\n"; - for (unsigned i = 0, e = ChainPreds.size(); i != e; i++) { + for (std::set<SUnit*>::iterator I = ChainPreds.begin(), + E = ChainPreds.end(); I != E; ++I) { std::cerr << " "; - ChainPreds[i]->dump(G, false); + (*I)->dump(G, false); } } if (Succs.size() != 0) { std::cerr << "Successors :\n"; - for (unsigned i = 0, e = Succs.size(); i != e; i++) { + for (std::set<SUnit*>::iterator I = Succs.begin(), + E = Succs.end(); I != E; ++I) { std::cerr << " "; - Succs[i]->dump(G, false); + (*I)->dump(G, false); } } if (ChainSuccs.size() != 0) { std::cerr << "Chained succs :\n"; - for (unsigned i = 0, e = ChainSuccs.size(); i != e; i++) { + for (std::set<SUnit*>::iterator I = ChainSuccs.begin(), + E = ChainSuccs.end(); I != E; ++I) { std::cerr << " "; - ChainSuccs[i]->dump(G, false); + (*I)->dump(G, false); } } } @@ -105,24 +116,30 @@ /// Sorting functions for the Available queue. struct ls_rr_sort : public std::binary_function<SUnit*, SUnit*, bool> { bool operator()(const SUnit* left, const SUnit* right) const { - if (left->Priority1 > right->Priority1) { + bool LFloater = (left ->Preds.size() == 0); + bool RFloater = (right->Preds.size() == 0); + int LBonus = (int)left ->isDefNUseOperand; + int RBonus = (int)right->isDefNUseOperand; + int LPriority1 = left ->Priority1 - LBonus; + int RPriority1 = right->Priority1 - RBonus; + int LPriority2 = left ->Priority2 + LBonus; + int RPriority2 = right->Priority2 + RBonus; + + // Favor floaters (i.e. node with no non-passive predecessors): + // e.g. MOV32ri. + if (!LFloater && RFloater) return true; - } else if (left->Priority1 == right->Priority1) { - unsigned lf = left->FlaggedNodes.size(); - unsigned rf = right->FlaggedNodes.size(); - if (lf > rf) + else if (LFloater == RFloater) + if (LPriority1 > RPriority1) return true; - else if (lf == rf) { - if (left->Priority2 > right->Priority2) + else if (LPriority1 == RPriority1) + if (LPriority2 < RPriority2) return true; - else if (left->Priority2 == right->Priority2) { + else if (LPriority1 == RPriority1) if (left->CycleBound > right->CycleBound) return true; else return left->Node->getNodeDepth() < right->Node->getNodeDepth(); - } - } - } return false; } @@ -163,7 +180,7 @@ private: SUnit *NewSUnit(SDNode *N); - void ReleasePred(SUnit *PredSU); + void ReleasePred(SUnit *PredSU, bool isChain = false); void ScheduleNode(SUnit *SU); int CalcNodePriority(SUnit *SU); void CalculatePriorities(); @@ -189,11 +206,21 @@ /// ReleasePred - Decrement the NumSuccsLeft count of a predecessor. Add it to /// the Available queue is the count reaches zero. Also update its cycle bound. -void ScheduleDAGList::ReleasePred(SUnit *PredSU) { +void ScheduleDAGList::ReleasePred(SUnit *PredSU, bool isChain) { SDNode *PredNode = PredSU->Node; - PredSU->NumSuccsLeft--; - if (PredSU->NumSuccsLeft == 0) { + // FIXME: the distance between two nodes is not always == the predecessor's + // latency. For example, the reader can very well read the register written + // by the predecessor later than the issue cycle. It also depends on the + // interrupt model (drain vs. freeze). + PredSU->CycleBound = std::max(PredSU->CycleBound, CurrCycle + PredSU->Latency); + + if (!isChain) { + PredSU->NumSuccsLeft--; + PredSU->Priority1++; + } else + PredSU->NumChainSuccsLeft--; + if (PredSU->NumSuccsLeft == 0 && PredSU->NumChainSuccsLeft == 0) { // EntryToken has to go last! if (PredNode->getOpcode() != ISD::EntryToken) Available.push(PredSU); @@ -205,12 +232,6 @@ assert(0); #endif } - - // FIXME: the distance between two nodes is not always == the predecessor's - // latency. For example, the reader can very well read the register written - // by the predecessor later than the issue cycle. It also depends on the - // interrupt model (drain vs. freeze). - PredSU->CycleBound = std::max(PredSU->CycleBound, CurrCycle + PredSU->Latency); } /// ScheduleNode - Add the node to the schedule. Decrement the pending count of @@ -221,10 +242,15 @@ SU->Slot = CurrCycle; // Bottom up: release predecessors - for (unsigned i = 0, e = SU->Preds.size(); i != e; i++) - ReleasePred(SU->Preds[i]); - for (unsigned i = 0, e = SU->ChainPreds.size(); i != e; i++) - ReleasePred(SU->ChainPreds[i]); + for (std::set<SUnit*>::iterator I1 = SU->Preds.begin(), + E1 = SU->Preds.end(); I1 != E1; ++I1) { + ReleasePred(*I1); + SU->NumPredsLeft--; + SU->Priority1--; + } + for (std::set<SUnit*>::iterator I2 = SU->ChainPreds.begin(), + E2 = SU->ChainPreds.end(); I2 != E2; ++I2) + ReleasePred(*I2, true); CurrCycle++; } @@ -272,7 +298,7 @@ #ifndef NDEBUG bool AnyNotSched = false; for (SUnit *SU = HeadSUnit; SU != NULL; SU = SU->Next) { - if (SU->NumSuccsLeft != 0) { + if (SU->NumSuccsLeft != 0 || SU->NumChainSuccsLeft != 0) { if (!AnyNotSched) std::cerr << "*** List scheduling failed! ***\n"; SU->dump(&DAG); @@ -292,22 +318,24 @@ DEBUG(std::cerr << "\n"); } -/// CalcNodePriority - Priority 1 is just the number of live range genned - number -/// of live range killed. Priority 2 is the Sethi Ullman number. It returns -/// priority 2 since it is calculated recursively. -/// Smaller number is the higher priority in both cases. +/// CalcNodePriority - Priority1 is just the number of live range genned - +/// number of live range killed. Priority2 is the Sethi Ullman number. It +/// returns Priority2 since it is calculated recursively. +/// Smaller number is the higher priority for Priority2. Reverse is true for +/// Priority1. int ScheduleDAGList::CalcNodePriority(SUnit *SU) { if (SU->Priority2 != INT_MIN) return SU->Priority2; - SU->Priority1 = SU->Preds.size() - SU->Succs.size(); + SU->Priority1 = SU->NumPredsLeft - SU->NumSuccsLeft; if (SU->Preds.size() == 0) { SU->Priority2 = 1; } else { int Extra = 0; - for (unsigned i = 0, e = SU->Preds.size(); i != e; i++) { - SUnit *PredSU = SU->Preds[i]; + for (std::set<SUnit*>::iterator I = SU->Preds.begin(), + E = SU->Preds.end(); I != E; ++I) { + SUnit *PredSU = *I; int PredPriority = CalcNodePriority(PredSU); if (PredPriority > SU->Priority2) { SU->Priority2 = PredPriority; @@ -387,14 +415,16 @@ assert(VT != MVT::Flag); SUnit *OpSU = SUnitMap[OpN]; if (VT == MVT::Other) { - SU ->ChainPreds.push_back(OpSU); - OpSU->ChainSuccs.push_back(SU); + if (SU->ChainPreds.insert(OpSU).second) + SU->NumChainPredsLeft++; + if (OpSU->ChainSuccs.insert(SU).second) + OpSU->NumChainSuccsLeft++; } else { - SU ->Preds.push_back(OpSU); - OpSU->Succs.push_back(SU); + if (SU->Preds.insert(OpSU).second) + SU->NumPredsLeft++; + if (OpSU->Succs.insert(SU).second) + OpSU->NumSuccsLeft++; } - SU->NumPredsLeft++; - OpSU->NumSuccsLeft++; } } } else { @@ -407,14 +437,18 @@ assert(VT != MVT::Flag); SUnit *OpSU = SUnitMap[OpN]; if (VT == MVT::Other) { - SU ->ChainPreds.push_back(OpSU); - OpSU->ChainSuccs.push_back(SU); + if (SU->ChainPreds.insert(OpSU).second) + SU->NumChainPredsLeft++; + if (OpSU->ChainSuccs.insert(SU).second) + OpSU->NumChainSuccsLeft++; } else { - SU ->Preds.push_back(OpSU); - OpSU->Succs.push_back(SU); + if (SU->Preds.insert(OpSU).second) + SU->NumPredsLeft++; + if (OpSU->Succs.insert(SU).second) + OpSU->NumSuccsLeft++; + if (j == 0 && TII->isTwoAddrInstr(N->getTargetOpcode())) + OpSU->isDefNUseOperand = true; } - SU->NumPredsLeft++; - OpSU->NumSuccsLeft++; } } } _______________________________________________ llvm-commits mailing list llvm-commits@cs.uiuc.edu http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits
