diff options
| -rw-r--r-- | llvm/include/llvm/CodeGen/GlobalISel/RegBankSelect.h | 7 | ||||
| -rw-r--r-- | llvm/lib/CodeGen/GlobalISel/RegBankSelect.cpp | 48 |
2 files changed, 45 insertions, 10 deletions
diff --git a/llvm/include/llvm/CodeGen/GlobalISel/RegBankSelect.h b/llvm/include/llvm/CodeGen/GlobalISel/RegBankSelect.h index 7b8601fc3ae..e8454e82f89 100644 --- a/llvm/include/llvm/CodeGen/GlobalISel/RegBankSelect.h +++ b/llvm/include/llvm/CodeGen/GlobalISel/RegBankSelect.h @@ -525,6 +525,13 @@ private: RegBankSelect::RepairingPlacement &RepairPt, const iterator_range<SmallVectorImpl<unsigned>::iterator> &NewVRegs); + /// Find the best mapping for \p MI from \p PossibleMappings. + /// \return a reference on the best mapping in \p PossibleMappings. + RegisterBankInfo::InstructionMapping & + findBestMapping(MachineInstr &MI, + RegisterBankInfo::InstructionMappings &PossibleMappings, + SmallVectorImpl<RepairingPlacement> &RepairPts); + /// Compute the cost of mapping \p MI with \p InstrMapping and /// compute the repairing placement for such mapping in \p /// RepairPts. diff --git a/llvm/lib/CodeGen/GlobalISel/RegBankSelect.cpp b/llvm/lib/CodeGen/GlobalISel/RegBankSelect.cpp index 152fc0c306c..4dc2bd8c81a 100644 --- a/llvm/lib/CodeGen/GlobalISel/RegBankSelect.cpp +++ b/llvm/lib/CodeGen/GlobalISel/RegBankSelect.cpp @@ -136,6 +136,27 @@ void RegBankSelect::repairReg( // Legalize NewInstrs if need be. } +RegisterBankInfo::InstructionMapping &RegBankSelect::findBestMapping( + MachineInstr &MI, RegisterBankInfo::InstructionMappings &PossibleMappings, + SmallVectorImpl<RepairingPlacement> &RepairPts) { + + RegisterBankInfo::InstructionMapping *BestMapping = nullptr; + MappingCost Cost = MappingCost::ImpossibleCost(); + SmallVector<RepairingPlacement, 4> LocalRepairPts; + for (RegisterBankInfo::InstructionMapping &CurMapping : PossibleMappings) { + MappingCost CurCost = computeMapping(MI, CurMapping, LocalRepairPts, &Cost); + if (CurCost < Cost) { + Cost = CurCost; + BestMapping = &CurMapping; + RepairPts.clear(); + for (RepairingPlacement &RepairPt : LocalRepairPts) + RepairPts.emplace_back(std::move(RepairPt)); + } + } + assert(BestMapping && "No suitable mapping for instruction"); + return *BestMapping; +} + void RegBankSelect::tryAvoidingSplit( RegBankSelect::RepairingPlacement &RepairPt, const MachineOperand &MO, const RegisterBankInfo::ValueMapping &ValMapping) const { @@ -433,22 +454,29 @@ void RegBankSelect::applyMapping( void RegBankSelect::assignInstr(MachineInstr &MI) { DEBUG(dbgs() << "Assign: " << MI); - RegisterBankInfo::InstructionMapping DefaultMapping = - RBI->getInstrMapping(MI); // Remember the repairing placement for all the operands. SmallVector<RepairingPlacement, 4> RepairPts; - MappingCost DefaultCost = computeMapping(MI, DefaultMapping, RepairPts); - (void)DefaultCost; - assert(DefaultCost != MappingCost::ImpossibleCost() && - "Default mapping is not suited"); - + RegisterBankInfo::InstructionMapping BestMapping; + if (OptMode == RegBankSelect::Mode::Fast) { + BestMapping = RBI->getInstrMapping(MI); + MappingCost DefaultCost = computeMapping(MI, BestMapping, RepairPts); + (void)DefaultCost; + assert(DefaultCost != MappingCost::ImpossibleCost() && + "Default mapping is not suited"); + } else { + RegisterBankInfo::InstructionMappings PossibleMappings = + RBI->getInstrPossibleMappings(MI); + assert(!PossibleMappings.empty() && + "Do not know how to map this instruction"); + BestMapping = std::move(findBestMapping(MI, PossibleMappings, RepairPts)); + } // Make sure the mapping is valid for MI. - assert(DefaultMapping.verify(MI) && "Invalid instruction mapping"); + assert(BestMapping.verify(MI) && "Invalid instruction mapping"); - DEBUG(dbgs() << "Mapping: " << DefaultMapping << '\n'); + DEBUG(dbgs() << "Mapping: " << BestMapping << '\n'); - applyMapping(MI, DefaultMapping, RepairPts); + applyMapping(MI, BestMapping, RepairPts); DEBUG(dbgs() << "Assigned: " << MI); } |
