diff options
| -rw-r--r-- | llvm/include/llvm/Target/TargetRegisterInfo.h | 9 | ||||
| -rw-r--r-- | llvm/lib/CodeGen/MachineScheduler.cpp | 26 |
2 files changed, 28 insertions, 7 deletions
diff --git a/llvm/include/llvm/Target/TargetRegisterInfo.h b/llvm/include/llvm/Target/TargetRegisterInfo.h index ffd510440b0..fccaad4705d 100644 --- a/llvm/include/llvm/Target/TargetRegisterInfo.h +++ b/llvm/include/llvm/Target/TargetRegisterInfo.h @@ -668,6 +668,15 @@ public: return 0; } + /// Return a heuristic for the machine scheduler to compare the profitability + /// of increasing one register pressure set versus another. The scheduler + /// will prefer increasing the register pressure of the set which returns + /// the largest value for this function. + virtual unsigned getRegPressureSetScore(const MachineFunction &MF, + unsigned PSetID) const { + return PSetID; + } + /// Get the weight in units of pressure for this register class. virtual const RegClassWeight &getRegClassWeight( const TargetRegisterClass *RC) const = 0; diff --git a/llvm/lib/CodeGen/MachineScheduler.cpp b/llvm/lib/CodeGen/MachineScheduler.cpp index a13dab3fe78..bcee15c7c75 100644 --- a/llvm/lib/CodeGen/MachineScheduler.cpp +++ b/llvm/lib/CodeGen/MachineScheduler.cpp @@ -2579,11 +2579,13 @@ static bool tryPressure(const PressureChange &TryP, const PressureChange &CandP, GenericSchedulerBase::SchedCandidate &TryCand, GenericSchedulerBase::SchedCandidate &Cand, - GenericSchedulerBase::CandReason Reason) { - int TryRank = TryP.getPSetOrMax(); - int CandRank = CandP.getPSetOrMax(); + GenericSchedulerBase::CandReason Reason, + const TargetRegisterInfo *TRI, + const MachineFunction &MF) { + unsigned TryPSet = TryP.getPSetOrMax(); + unsigned CandPSet = CandP.getPSetOrMax(); // If both candidates affect the same set, go with the smallest increase. - if (TryRank == CandRank) { + if (TryPSet == CandPSet) { return tryLess(TryP.getUnitInc(), CandP.getUnitInc(), TryCand, Cand, Reason); } @@ -2593,6 +2595,13 @@ static bool tryPressure(const PressureChange &TryP, Reason)) { return true; } + + int TryRank = TryP.isValid() ? TRI->getRegPressureSetScore(MF, TryPSet) : + std::numeric_limits<int>::max(); + + int CandRank = CandP.isValid() ? TRI->getRegPressureSetScore(MF, CandPSet) : + std::numeric_limits<int>::max(); + // If the candidates are decreasing pressure, reverse priority. if (TryP.getUnitInc() < 0) std::swap(TryRank, CandRank); @@ -2695,13 +2704,15 @@ void GenericScheduler::tryCandidate(SchedCandidate &Cand, // Avoid exceeding the target's limit. if (DAG->isTrackingPressure() && tryPressure(TryCand.RPDelta.Excess, Cand.RPDelta.Excess, - TryCand, Cand, RegExcess)) + TryCand, Cand, RegExcess, TRI, + DAG->MF)) return; // Avoid increasing the max critical pressure in the scheduled region. if (DAG->isTrackingPressure() && tryPressure(TryCand.RPDelta.CriticalMax, Cand.RPDelta.CriticalMax, - TryCand, Cand, RegCritical)) + TryCand, Cand, RegCritical, TRI, + DAG->MF)) return; // For loops that are acyclic path limited, aggressively schedule for latency. @@ -2737,7 +2748,8 @@ void GenericScheduler::tryCandidate(SchedCandidate &Cand, // Avoid increasing the max pressure of the entire region. if (DAG->isTrackingPressure() && tryPressure(TryCand.RPDelta.CurrentMax, Cand.RPDelta.CurrentMax, - TryCand, Cand, RegMax)) + TryCand, Cand, RegMax, TRI, + DAG->MF)) return; // Avoid critical resource consumption and balance the schedule. |
