diff options
Diffstat (limited to 'lib/CodeGen/AggressiveAntiDepBreaker.cpp')
| -rw-r--r-- | lib/CodeGen/AggressiveAntiDepBreaker.cpp | 36 |
1 files changed, 26 insertions, 10 deletions
diff --git a/lib/CodeGen/AggressiveAntiDepBreaker.cpp b/lib/CodeGen/AggressiveAntiDepBreaker.cpp index 5506a1f526..ffb6315427 100644 --- a/lib/CodeGen/AggressiveAntiDepBreaker.cpp +++ b/lib/CodeGen/AggressiveAntiDepBreaker.cpp @@ -14,7 +14,7 @@ // //===----------------------------------------------------------------------===// -#define DEBUG_TYPE "aggressive-antidep" +#define DEBUG_TYPE "post-RA-sched" #include "AggressiveAntiDepBreaker.h" #include "llvm/CodeGen/MachineBasicBlock.h" #include "llvm/CodeGen/MachineFrameInfo.h" @@ -31,7 +31,7 @@ using namespace llvm; static cl::opt<int> AntiDepTrials("agg-antidep-trials", cl::desc("Maximum number of anti-dependency breaking passes"), - cl::init(2), cl::Hidden); + cl::init(1), cl::Hidden); AggressiveAntiDepState::AggressiveAntiDepState(MachineBasicBlock *BB) : GroupNodes(TargetRegisterInfo::FirstVirtualRegister, 0) { @@ -265,18 +265,24 @@ void AggressiveAntiDepBreaker::GetPassthruRegs(MachineInstr *MI, } /// AntiDepPathStep - Return SUnit that SU has an anti-dependence on. -static void AntiDepPathStep(SUnit *SU, std::vector<SDep*>& Edges) { - SmallSet<unsigned, 8> Dups; +static void AntiDepPathStep(SUnit *SU, AntiDepBreaker::AntiDepRegVector& Regs, + std::vector<SDep*>& Edges) { + AntiDepBreaker::AntiDepRegSet RegSet; + for (unsigned i = 0, e = Regs.size(); i < e; ++i) + RegSet.insert(Regs[i]); + for (SUnit::pred_iterator P = SU->Preds.begin(), PE = SU->Preds.end(); P != PE; ++P) { if (P->getKind() == SDep::Anti) { unsigned Reg = P->getReg(); - if (Dups.count(Reg) == 0) { + if (RegSet.count(Reg) != 0) { Edges.push_back(&*P); - Dups.insert(Reg); + RegSet.erase(Reg); } } } + + assert(RegSet.empty() && "Expected all antidep registers to be found"); } void AggressiveAntiDepBreaker::HandleLastUse(unsigned Reg, unsigned KillIdx, @@ -593,6 +599,7 @@ bool AggressiveAntiDepBreaker::FindSuitableFreeRegisters( /// unsigned AggressiveAntiDepBreaker::BreakAntiDependencies( std::vector<SUnit>& SUnits, + CandidateMap& Candidates, MachineBasicBlock::iterator& Begin, MachineBasicBlock::iterator& End, unsigned InsertPosIndex) { @@ -601,9 +608,15 @@ unsigned AggressiveAntiDepBreaker::BreakAntiDependencies( std::multimap<unsigned, AggressiveAntiDepState::RegisterReference>& RegRefs = State->GetRegRefs(); + // Nothing to do if no candidates. + if (Candidates.empty()) { + DEBUG(errs() << "\n===== No anti-dependency candidates\n"); + return 0; + } + // The code below assumes that there is at least one instruction, // so just duck out immediately if the block is empty. - if (SUnits.empty()) return false; + if (SUnits.empty()) return 0; // Manage saved state to enable multiple passes... if (AntiDepTrials > 1) { @@ -618,7 +631,8 @@ unsigned AggressiveAntiDepBreaker::BreakAntiDependencies( // ...need a map from MI to SUnit. std::map<MachineInstr *, SUnit *> MISUnitMap; - DEBUG(errs() << "Breaking all anti-dependencies\n"); + DEBUG(errs() << "\n===== Attempting to break " << Candidates.size() << + " anti-dependencies\n"); for (unsigned i = 0, e = SUnits.size(); i != e; ++i) { SUnit *SU = &SUnits[i]; MISUnitMap.insert(std::pair<MachineInstr *, SUnit *>(SU->getInstr(), SU)); @@ -655,8 +669,10 @@ unsigned AggressiveAntiDepBreaker::BreakAntiDependencies( std::vector<SDep*> Edges; SUnit *PathSU = MISUnitMap[MI]; - if (PathSU) - AntiDepPathStep(PathSU, Edges); + AntiDepBreaker::CandidateMap::iterator + citer = Candidates.find(PathSU); + if (citer != Candidates.end()) + AntiDepPathStep(PathSU, citer->second, Edges); // Ignore KILL instructions (they form a group in ScanInstruction // but don't cause any anti-dependence breaking themselves) |