diff options
Diffstat (limited to 'contrib/llvm/lib/CodeGen/SplitKit.cpp')
| -rw-r--r-- | contrib/llvm/lib/CodeGen/SplitKit.cpp | 1491 |
1 files changed, 712 insertions, 779 deletions
diff --git a/contrib/llvm/lib/CodeGen/SplitKit.cpp b/contrib/llvm/lib/CodeGen/SplitKit.cpp index 29474f0..5663936 100644 --- a/contrib/llvm/lib/CodeGen/SplitKit.cpp +++ b/contrib/llvm/lib/CodeGen/SplitKit.cpp @@ -12,13 +12,14 @@ // //===----------------------------------------------------------------------===// -#define DEBUG_TYPE "splitter" +#define DEBUG_TYPE "regalloc" #include "SplitKit.h" +#include "LiveRangeEdit.h" #include "VirtRegMap.h" #include "llvm/CodeGen/CalcSpillWeights.h" #include "llvm/CodeGen/LiveIntervalAnalysis.h" +#include "llvm/CodeGen/MachineDominators.h" #include "llvm/CodeGen/MachineInstrBuilder.h" -#include "llvm/CodeGen/MachineLoopInfo.h" #include "llvm/CodeGen/MachineRegisterInfo.h" #include "llvm/Support/CommandLine.h" #include "llvm/Support/Debug.h" @@ -36,371 +37,231 @@ AllowSplit("spiller-splits-edges", // Split Analysis //===----------------------------------------------------------------------===// -SplitAnalysis::SplitAnalysis(const MachineFunction &mf, +SplitAnalysis::SplitAnalysis(const VirtRegMap &vrm, const LiveIntervals &lis, const MachineLoopInfo &mli) - : mf_(mf), - lis_(lis), - loops_(mli), - tii_(*mf.getTarget().getInstrInfo()), - curli_(0) {} + : MF(vrm.getMachineFunction()), + VRM(vrm), + LIS(lis), + Loops(mli), + TII(*MF.getTarget().getInstrInfo()), + CurLI(0) {} void SplitAnalysis::clear() { - usingInstrs_.clear(); - usingBlocks_.clear(); - usingLoops_.clear(); - curli_ = 0; + UseSlots.clear(); + UsingInstrs.clear(); + UsingBlocks.clear(); + LiveBlocks.clear(); + CurLI = 0; } bool SplitAnalysis::canAnalyzeBranch(const MachineBasicBlock *MBB) { MachineBasicBlock *T, *F; SmallVector<MachineOperand, 4> Cond; - return !tii_.AnalyzeBranch(const_cast<MachineBasicBlock&>(*MBB), T, F, Cond); + return !TII.AnalyzeBranch(const_cast<MachineBasicBlock&>(*MBB), T, F, Cond); } -/// analyzeUses - Count instructions, basic blocks, and loops using curli. +/// analyzeUses - Count instructions, basic blocks, and loops using CurLI. void SplitAnalysis::analyzeUses() { - const MachineRegisterInfo &MRI = mf_.getRegInfo(); - for (MachineRegisterInfo::reg_iterator I = MRI.reg_begin(curli_->reg); - MachineInstr *MI = I.skipInstruction();) { - if (MI->isDebugValue() || !usingInstrs_.insert(MI)) + const MachineRegisterInfo &MRI = MF.getRegInfo(); + for (MachineRegisterInfo::reg_iterator I = MRI.reg_begin(CurLI->reg), + E = MRI.reg_end(); I != E; ++I) { + MachineOperand &MO = I.getOperand(); + if (MO.isUse() && MO.isUndef()) continue; - MachineBasicBlock *MBB = MI->getParent(); - if (usingBlocks_[MBB]++) + MachineInstr *MI = MO.getParent(); + if (MI->isDebugValue() || !UsingInstrs.insert(MI)) continue; - if (MachineLoop *Loop = loops_.getLoopFor(MBB)) - usingLoops_[Loop]++; + UseSlots.push_back(LIS.getInstructionIndex(MI).getDefIndex()); + MachineBasicBlock *MBB = MI->getParent(); + UsingBlocks[MBB]++; } + array_pod_sort(UseSlots.begin(), UseSlots.end()); + calcLiveBlockInfo(); DEBUG(dbgs() << " counted " - << usingInstrs_.size() << " instrs, " - << usingBlocks_.size() << " blocks, " - << usingLoops_.size() << " loops.\n"); + << UsingInstrs.size() << " instrs, " + << UsingBlocks.size() << " blocks.\n"); } -/// removeUse - Update statistics by noting that MI no longer uses curli. -void SplitAnalysis::removeUse(const MachineInstr *MI) { - if (!usingInstrs_.erase(MI)) +/// calcLiveBlockInfo - Fill the LiveBlocks array with information about blocks +/// where CurLI is live. +void SplitAnalysis::calcLiveBlockInfo() { + if (CurLI->empty()) return; - // Decrement MBB count. - const MachineBasicBlock *MBB = MI->getParent(); - BlockCountMap::iterator bi = usingBlocks_.find(MBB); - assert(bi != usingBlocks_.end() && "MBB missing"); - assert(bi->second && "0 count in map"); - if (--bi->second) - return; - // No more uses in MBB. - usingBlocks_.erase(bi); + LiveInterval::const_iterator LVI = CurLI->begin(); + LiveInterval::const_iterator LVE = CurLI->end(); + + SmallVectorImpl<SlotIndex>::const_iterator UseI, UseE; + UseI = UseSlots.begin(); + UseE = UseSlots.end(); + + // Loop over basic blocks where CurLI is live. + MachineFunction::iterator MFI = LIS.getMBBFromIndex(LVI->start); + for (;;) { + BlockInfo BI; + BI.MBB = MFI; + SlotIndex Start, Stop; + tie(Start, Stop) = LIS.getSlotIndexes()->getMBBRange(BI.MBB); + + // The last split point is the latest possible insertion point that dominates + // all successor blocks. If interference reaches LastSplitPoint, it is not + // possible to insert a split or reload that makes CurLI live in the + // outgoing bundle. + MachineBasicBlock::iterator LSP = LIS.getLastSplitPoint(*CurLI, BI.MBB); + if (LSP == BI.MBB->end()) + BI.LastSplitPoint = Stop; + else + BI.LastSplitPoint = LIS.getInstructionIndex(LSP); + + // LVI is the first live segment overlapping MBB. + BI.LiveIn = LVI->start <= Start; + if (!BI.LiveIn) + BI.Def = LVI->start; + + // Find the first and last uses in the block. + BI.Uses = hasUses(MFI); + if (BI.Uses && UseI != UseE) { + BI.FirstUse = *UseI; + assert(BI.FirstUse >= Start); + do ++UseI; + while (UseI != UseE && *UseI < Stop); + BI.LastUse = UseI[-1]; + assert(BI.LastUse < Stop); + } - // Decrement loop count. - MachineLoop *Loop = loops_.getLoopFor(MBB); - if (!Loop) - return; - LoopCountMap::iterator li = usingLoops_.find(Loop); - assert(li != usingLoops_.end() && "Loop missing"); - assert(li->second && "0 count in map"); - if (--li->second) - return; - // No more blocks in Loop. - usingLoops_.erase(li); -} + // Look for gaps in the live range. + bool hasGap = false; + BI.LiveOut = true; + while (LVI->end < Stop) { + SlotIndex LastStop = LVI->end; + if (++LVI == LVE || LVI->start >= Stop) { + BI.Kill = LastStop; + BI.LiveOut = false; + break; + } + if (LastStop < LVI->start) { + hasGap = true; + BI.Kill = LastStop; + BI.Def = LVI->start; + } + } -// Get three sets of basic blocks surrounding a loop: Blocks inside the loop, -// predecessor blocks, and exit blocks. -void SplitAnalysis::getLoopBlocks(const MachineLoop *Loop, LoopBlocks &Blocks) { - Blocks.clear(); - - // Blocks in the loop. - Blocks.Loop.insert(Loop->block_begin(), Loop->block_end()); - - // Predecessor blocks. - const MachineBasicBlock *Header = Loop->getHeader(); - for (MachineBasicBlock::const_pred_iterator I = Header->pred_begin(), - E = Header->pred_end(); I != E; ++I) - if (!Blocks.Loop.count(*I)) - Blocks.Preds.insert(*I); - - // Exit blocks. - for (MachineLoop::block_iterator I = Loop->block_begin(), - E = Loop->block_end(); I != E; ++I) { - const MachineBasicBlock *MBB = *I; - for (MachineBasicBlock::const_succ_iterator SI = MBB->succ_begin(), - SE = MBB->succ_end(); SI != SE; ++SI) - if (!Blocks.Loop.count(*SI)) - Blocks.Exits.insert(*SI); - } -} + // Don't set LiveThrough when the block has a gap. + BI.LiveThrough = !hasGap && BI.LiveIn && BI.LiveOut; + LiveBlocks.push_back(BI); -/// analyzeLoopPeripheralUse - Return an enum describing how curli_ is used in -/// and around the Loop. -SplitAnalysis::LoopPeripheralUse SplitAnalysis:: -analyzeLoopPeripheralUse(const SplitAnalysis::LoopBlocks &Blocks) { - LoopPeripheralUse use = ContainedInLoop; - for (BlockCountMap::iterator I = usingBlocks_.begin(), E = usingBlocks_.end(); - I != E; ++I) { - const MachineBasicBlock *MBB = I->first; - // Is this a peripheral block? - if (use < MultiPeripheral && - (Blocks.Preds.count(MBB) || Blocks.Exits.count(MBB))) { - if (I->second > 1) use = MultiPeripheral; - else use = SinglePeripheral; - continue; - } - // Is it a loop block? - if (Blocks.Loop.count(MBB)) - continue; - // It must be an unrelated block. - return OutsideLoop; - } - return use; -} + // LVI is now at LVE or LVI->end >= Stop. + if (LVI == LVE) + break; -/// getCriticalExits - It may be necessary to partially break critical edges -/// leaving the loop if an exit block has phi uses of curli. Collect the exit -/// blocks that need special treatment into CriticalExits. -void SplitAnalysis::getCriticalExits(const SplitAnalysis::LoopBlocks &Blocks, - BlockPtrSet &CriticalExits) { - CriticalExits.clear(); - - // A critical exit block contains a phi def of curli, and has a predecessor - // that is not in the loop nor a loop predecessor. - // For such an exit block, the edges carrying the new variable must be moved - // to a new pre-exit block. - for (BlockPtrSet::iterator I = Blocks.Exits.begin(), E = Blocks.Exits.end(); - I != E; ++I) { - const MachineBasicBlock *Succ = *I; - SlotIndex SuccIdx = lis_.getMBBStartIdx(Succ); - VNInfo *SuccVNI = curli_->getVNInfoAt(SuccIdx); - // This exit may not have curli live in at all. No need to split. - if (!SuccVNI) - continue; - // If this is not a PHI def, it is either using a value from before the - // loop, or a value defined inside the loop. Both are safe. - if (!SuccVNI->isPHIDef() || SuccVNI->def.getBaseIndex() != SuccIdx) - continue; - // This exit block does have a PHI. Does it also have a predecessor that is - // not a loop block or loop predecessor? - for (MachineBasicBlock::const_pred_iterator PI = Succ->pred_begin(), - PE = Succ->pred_end(); PI != PE; ++PI) { - const MachineBasicBlock *Pred = *PI; - if (Blocks.Loop.count(Pred) || Blocks.Preds.count(Pred)) - continue; - // This is a critical exit block, and we need to split the exit edge. - CriticalExits.insert(Succ); + // Live segment ends exactly at Stop. Move to the next segment. + if (LVI->end == Stop && ++LVI == LVE) break; - } + + // Pick the next basic block. + if (LVI->start < Stop) + ++MFI; + else + MFI = LIS.getMBBFromIndex(LVI->start); } } -/// canSplitCriticalExits - Return true if it is possible to insert new exit -/// blocks before the blocks in CriticalExits. -bool -SplitAnalysis::canSplitCriticalExits(const SplitAnalysis::LoopBlocks &Blocks, - BlockPtrSet &CriticalExits) { - // If we don't allow critical edge splitting, require no critical exits. - if (!AllowSplit) - return CriticalExits.empty(); - - for (BlockPtrSet::iterator I = CriticalExits.begin(), E = CriticalExits.end(); - I != E; ++I) { - const MachineBasicBlock *Succ = *I; - // We want to insert a new pre-exit MBB before Succ, and change all the - // in-loop blocks to branch to the pre-exit instead of Succ. - // Check that all the in-loop predecessors can be changed. - for (MachineBasicBlock::const_pred_iterator PI = Succ->pred_begin(), - PE = Succ->pred_end(); PI != PE; ++PI) { - const MachineBasicBlock *Pred = *PI; - // The external predecessors won't be altered. - if (!Blocks.Loop.count(Pred) && !Blocks.Preds.count(Pred)) - continue; - if (!canAnalyzeBranch(Pred)) - return false; - } - - // If Succ's layout predecessor falls through, that too must be analyzable. - // We need to insert the pre-exit block in the gap. - MachineFunction::const_iterator MFI = Succ; - if (MFI == mf_.begin()) - continue; - if (!canAnalyzeBranch(--MFI)) - return false; +void SplitAnalysis::print(const BlockPtrSet &B, raw_ostream &OS) const { + for (BlockPtrSet::const_iterator I = B.begin(), E = B.end(); I != E; ++I) { + unsigned count = UsingBlocks.lookup(*I); + OS << " BB#" << (*I)->getNumber(); + if (count) + OS << '(' << count << ')'; } - // No problems found. - return true; } void SplitAnalysis::analyze(const LiveInterval *li) { clear(); - curli_ = li; + CurLI = li; analyzeUses(); } -const MachineLoop *SplitAnalysis::getBestSplitLoop() { - assert(curli_ && "Call analyze() before getBestSplitLoop"); - if (usingLoops_.empty()) - return 0; - - LoopPtrSet Loops, SecondLoops; - LoopBlocks Blocks; - BlockPtrSet CriticalExits; - - // Find first-class and second class candidate loops. - // We prefer to split around loops where curli is used outside the periphery. - for (LoopCountMap::const_iterator I = usingLoops_.begin(), - E = usingLoops_.end(); I != E; ++I) { - const MachineLoop *Loop = I->first; - getLoopBlocks(Loop, Blocks); - - // FIXME: We need an SSA updater to properly handle multiple exit blocks. - if (Blocks.Exits.size() > 1) { - DEBUG(dbgs() << " multiple exits from " << *Loop); - continue; - } - - LoopPtrSet *LPS = 0; - switch(analyzeLoopPeripheralUse(Blocks)) { - case OutsideLoop: - LPS = &Loops; - break; - case MultiPeripheral: - LPS = &SecondLoops; - break; - case ContainedInLoop: - DEBUG(dbgs() << " contained in " << *Loop); - continue; - case SinglePeripheral: - DEBUG(dbgs() << " single peripheral use in " << *Loop); - continue; - } - // Will it be possible to split around this loop? - getCriticalExits(Blocks, CriticalExits); - DEBUG(dbgs() << " " << CriticalExits.size() << " critical exits from " - << *Loop); - if (!canSplitCriticalExits(Blocks, CriticalExits)) - continue; - // This is a possible split. - assert(LPS); - LPS->insert(Loop); - } - - DEBUG(dbgs() << " getBestSplitLoop found " << Loops.size() << " + " - << SecondLoops.size() << " candidate loops.\n"); - - // If there are no first class loops available, look at second class loops. - if (Loops.empty()) - Loops = SecondLoops; - if (Loops.empty()) - return 0; +//===----------------------------------------------------------------------===// +// LiveIntervalMap +//===----------------------------------------------------------------------===// - // Pick the earliest loop. - // FIXME: Are there other heuristics to consider? - const MachineLoop *Best = 0; - SlotIndex BestIdx; - for (LoopPtrSet::const_iterator I = Loops.begin(), E = Loops.end(); I != E; - ++I) { - SlotIndex Idx = lis_.getMBBStartIdx((*I)->getHeader()); - if (!Best || Idx < BestIdx) - Best = *I, BestIdx = Idx; - } - DEBUG(dbgs() << " getBestSplitLoop found " << *Best); - return Best; +// Work around the fact that the std::pair constructors are broken for pointer +// pairs in some implementations. makeVV(x, 0) works. +static inline std::pair<const VNInfo*, VNInfo*> +makeVV(const VNInfo *a, VNInfo *b) { + return std::make_pair(a, b); } -/// getMultiUseBlocks - if curli has more than one use in a basic block, it -/// may be an advantage to split curli for the duration of the block. -bool SplitAnalysis::getMultiUseBlocks(BlockPtrSet &Blocks) { - // If curli is local to one block, there is no point to splitting it. - if (usingBlocks_.size() <= 1) - return false; - // Add blocks with multiple uses. - for (BlockCountMap::iterator I = usingBlocks_.begin(), E = usingBlocks_.end(); - I != E; ++I) - switch (I->second) { - case 0: - case 1: - continue; - case 2: { - // It doesn't pay to split a 2-instr block if it redefines curli. - VNInfo *VN1 = curli_->getVNInfoAt(lis_.getMBBStartIdx(I->first)); - VNInfo *VN2 = - curli_->getVNInfoAt(lis_.getMBBEndIdx(I->first).getPrevIndex()); - // live-in and live-out with a different value. - if (VN1 && VN2 && VN1 != VN2) - continue; - } // Fall through. - default: - Blocks.insert(I->first); - } - return !Blocks.empty(); +void LiveIntervalMap::reset(LiveInterval *li) { + LI = li; + Values.clear(); + LiveOutCache.clear(); } -//===----------------------------------------------------------------------===// -// LiveIntervalMap -//===----------------------------------------------------------------------===// +bool LiveIntervalMap::isComplexMapped(const VNInfo *ParentVNI) const { + ValueMap::const_iterator i = Values.find(ParentVNI); + return i != Values.end() && i->second == 0; +} -// defValue - Introduce a li_ def for ParentVNI that could be later than +// defValue - Introduce a LI def for ParentVNI that could be later than // ParentVNI->def. VNInfo *LiveIntervalMap::defValue(const VNInfo *ParentVNI, SlotIndex Idx) { + assert(LI && "call reset first"); assert(ParentVNI && "Mapping NULL value"); assert(Idx.isValid() && "Invalid SlotIndex"); - assert(parentli_.getVNInfoAt(Idx) == ParentVNI && "Bad ParentVNI"); - - // Is this a simple 1-1 mapping? Not likely. - if (Idx == ParentVNI->def) - return mapValue(ParentVNI, Idx); - - // This is a complex def. Mark with a NULL in valueMap. - VNInfo *OldVNI = - valueMap_.insert( - ValueMap::value_type(ParentVNI, static_cast<VNInfo *>(0))).first->second; - // The static_cast<VNInfo *> is only needed to work around a bug in an - // old version of the C++0x standard which the following compilers - // implemented and have yet to fix: - // - // Microsoft Visual Studio 2010 Version 10.0.30319.1 RTMRel - // Microsoft (R) 32-bit C/C++ Optimizing Compiler Version 16.00.30319.01 - // - // If/When we move to C++0x, this can be replaced by nullptr. - (void)OldVNI; - assert(OldVNI == 0 && "Simple/Complex values mixed"); - - // Should we insert a minimal snippet of VNI LiveRange, or can we count on - // callers to do that? We need it for lookups of complex values. - VNInfo *VNI = li_.getNextValue(Idx, 0, true, lis_.getVNInfoAllocator()); + assert(ParentLI.getVNInfoAt(Idx) == ParentVNI && "Bad ParentVNI"); + + // Create a new value. + VNInfo *VNI = LI->getNextValue(Idx, 0, LIS.getVNInfoAllocator()); + + // Preserve the PHIDef bit. + if (ParentVNI->isPHIDef() && Idx == ParentVNI->def) + VNI->setIsPHIDef(true); + + // Use insert for lookup, so we can add missing values with a second lookup. + std::pair<ValueMap::iterator,bool> InsP = + Values.insert(makeVV(ParentVNI, Idx == ParentVNI->def ? VNI : 0)); + + // This is now a complex def. Mark with a NULL in valueMap. + if (!InsP.second) + InsP.first->second = 0; + return VNI; } + // mapValue - Find the mapped value for ParentVNI at Idx. // Potentially create phi-def values. -VNInfo *LiveIntervalMap::mapValue(const VNInfo *ParentVNI, SlotIndex Idx) { +VNInfo *LiveIntervalMap::mapValue(const VNInfo *ParentVNI, SlotIndex Idx, + bool *simple) { + assert(LI && "call reset first"); assert(ParentVNI && "Mapping NULL value"); assert(Idx.isValid() && "Invalid SlotIndex"); - assert(parentli_.getVNInfoAt(Idx) == ParentVNI && "Bad ParentVNI"); + assert(ParentLI.getVNInfoAt(Idx) == ParentVNI && "Bad ParentVNI"); // Use insert for lookup, so we can add missing values with a second lookup. std::pair<ValueMap::iterator,bool> InsP = - valueMap_.insert(ValueMap::value_type(ParentVNI, static_cast<VNInfo *>(0))); - // The static_cast<VNInfo *> is only needed to work around a bug in an - // old version of the C++0x standard which the following compilers - // implemented and have yet to fix: - // - // Microsoft Visual Studio 2010 Version 10.0.30319.1 RTMRel - // Microsoft (R) 32-bit C/C++ Optimizing Compiler Version 16.00.30319.01 - // - // If/When we move to C++0x, this can be replaced by nullptr. + Values.insert(makeVV(ParentVNI, 0)); // This was an unknown value. Create a simple mapping. - if (InsP.second) - return InsP.first->second = li_.createValueCopy(ParentVNI, - lis_.getVNInfoAllocator()); + if (InsP.second) { + if (simple) *simple = true; + return InsP.first->second = LI->createValueCopy(ParentVNI, + LIS.getVNInfoAllocator()); + } + // This was a simple mapped value. - if (InsP.first->second) + if (InsP.first->second) { + if (simple) *simple = true; return InsP.first->second; + } // This is a complex mapped value. There may be multiple defs, and we may need // to create phi-defs. - MachineBasicBlock *IdxMBB = lis_.getMBBFromIndex(Idx); + if (simple) *simple = false; + MachineBasicBlock *IdxMBB = LIS.getMBBFromIndex(Idx); assert(IdxMBB && "No MBB at Idx"); // Is there a def in the same MBB we can extend? @@ -409,157 +270,260 @@ VNInfo *LiveIntervalMap::mapValue(const VNInfo *ParentVNI, SlotIndex Idx) { // Now for the fun part. We know that ParentVNI potentially has multiple defs, // and we may need to create even more phi-defs to preserve VNInfo SSA form. - // Perform a depth-first search for predecessor blocks where we know the - // dominating VNInfo. Insert phi-def VNInfos along the path back to IdxMBB. - - // Track MBBs where we have created or learned the dominating value. - // This may change during the DFS as we create new phi-defs. - typedef DenseMap<MachineBasicBlock*, VNInfo*> MBBValueMap; - MBBValueMap DomValue; - - for (idf_iterator<MachineBasicBlock*> - IDFI = idf_begin(IdxMBB), - IDFE = idf_end(IdxMBB); IDFI != IDFE;) { - MachineBasicBlock *MBB = *IDFI; - SlotIndex End = lis_.getMBBEndIdx(MBB); - - // We are operating on the restricted CFG where ParentVNI is live. - if (parentli_.getVNInfoAt(End.getPrevSlot()) != ParentVNI) { - IDFI.skipChildren(); - continue; - } - - // Do we have a dominating value in this block? - VNInfo *VNI = extendTo(MBB, End); - if (!VNI) { - ++IDFI; - continue; + // Perform a search for all predecessor blocks where we know the dominating + // VNInfo. Insert phi-def VNInfos along the path back to IdxMBB. + DEBUG(dbgs() << "\n Reaching defs for BB#" << IdxMBB->getNumber() + << " at " << Idx << " in " << *LI << '\n'); + + // Blocks where LI should be live-in. + SmallVector<MachineDomTreeNode*, 16> LiveIn; + LiveIn.push_back(MDT[IdxMBB]); + + // Using LiveOutCache as a visited set, perform a BFS for all reaching defs. + for (unsigned i = 0; i != LiveIn.size(); ++i) { + MachineBasicBlock *MBB = LiveIn[i]->getBlock(); + for (MachineBasicBlock::pred_iterator PI = MBB->pred_begin(), + PE = MBB->pred_end(); PI != PE; ++PI) { + MachineBasicBlock *Pred = *PI; + // Is this a known live-out block? + std::pair<LiveOutMap::iterator,bool> LOIP = + LiveOutCache.insert(std::make_pair(Pred, LiveOutPair())); + // Yes, we have been here before. + if (!LOIP.second) { + DEBUG(if (VNInfo *VNI = LOIP.first->second.first) + dbgs() << " known valno #" << VNI->id + << " at BB#" << Pred->getNumber() << '\n'); + continue; + } + + // Does Pred provide a live-out value? + SlotIndex Last = LIS.getMBBEndIdx(Pred).getPrevSlot(); + if (VNInfo *VNI = extendTo(Pred, Last)) { + MachineBasicBlock *DefMBB = LIS.getMBBFromIndex(VNI->def); + DEBUG(dbgs() << " found valno #" << VNI->id + << " from BB#" << DefMBB->getNumber() + << " at BB#" << Pred->getNumber() << '\n'); + LiveOutPair &LOP = LOIP.first->second; + LOP.first = VNI; + LOP.second = MDT[DefMBB]; + continue; + } + // No, we need a live-in value for Pred as well + if (Pred != IdxMBB) + LiveIn.push_back(MDT[Pred]); } + } - // Yes, VNI dominates MBB. Track the path back to IdxMBB, creating phi-defs - // as needed along the way. - for (unsigned PI = IDFI.getPathLength()-1; PI != 0; --PI) { - // Start from MBB's immediate successor. End at IdxMBB. - MachineBasicBlock *Succ = IDFI.getPath(PI-1); - std::pair<MBBValueMap::iterator, bool> InsP = - DomValue.insert(MBBValueMap::value_type(Succ, VNI)); - - // This is the first time we backtrack to Succ. - if (InsP.second) - continue; - - // We reached Succ again with the same VNI. Nothing is going to change. - VNInfo *OVNI = InsP.first->second; - if (OVNI == VNI) - break; + // We may need to add phi-def values to preserve the SSA form. + // This is essentially the same iterative algorithm that SSAUpdater uses, + // except we already have a dominator tree, so we don't have to recompute it. + VNInfo *IdxVNI = 0; + unsigned Changes; + do { + Changes = 0; + DEBUG(dbgs() << " Iterating over " << LiveIn.size() << " blocks.\n"); + // Propagate live-out values down the dominator tree, inserting phi-defs when + // necessary. Since LiveIn was created by a BFS, going backwards makes it more + // likely for us to visit immediate dominators before their children. + for (unsigned i = LiveIn.size(); i; --i) { + MachineDomTreeNode *Node = LiveIn[i-1]; + MachineBasicBlock *MBB = Node->getBlock(); + MachineDomTreeNode *IDom = Node->getIDom(); + LiveOutPair IDomValue; + // We need a live-in value to a block with no immediate dominator? + // This is probably an unreachable block that has survived somehow. + bool needPHI = !IDom; + + // Get the IDom live-out value. + if (!needPHI) { + LiveOutMap::iterator I = LiveOutCache.find(IDom->getBlock()); + if (I != LiveOutCache.end()) + IDomValue = I->second; + else + // If IDom is outside our set of live-out blocks, there must be new + // defs, and we need a phi-def here. + needPHI = true; + } - // Succ already has a phi-def. No need to continue. - SlotIndex Start = lis_.getMBBStartIdx(Succ); - if (OVNI->def == Start) - break; + // IDom dominates all of our predecessors, but it may not be the immediate + // dominator. Check if any of them have live-out values that are properly + // dominated by IDom. If so, we need a phi-def here. + if (!needPHI) { + for (MachineBasicBlock::pred_iterator PI = MBB->pred_begin(), + PE = MBB->pred_end(); PI != PE; ++PI) { + LiveOutPair Value = LiveOutCache[*PI]; + if (!Value.first || Value.first == IDomValue.first) + continue; + // This predecessor is carrying something other than IDomValue. + // It could be because IDomValue hasn't propagated yet, or it could be + // because MBB is in the dominance frontier of that value. + if (MDT.dominates(IDom, Value.second)) { + needPHI = true; + break; + } + } + } - // We have a collision between the old and new VNI at Succ. That means - // neither dominates and we need a new phi-def. - VNI = li_.getNextValue(Start, 0, true, lis_.getVNInfoAllocator()); - VNI->setIsPHIDef(true); - InsP.first->second = VNI; - - // Replace OVNI with VNI in the remaining path. - for (; PI > 1 ; --PI) { - MBBValueMap::iterator I = DomValue.find(IDFI.getPath(PI-2)); - if (I == DomValue.end() || I->second != OVNI) - break; - I->second = VNI; + // Create a phi-def if required. + if (needPHI) { + ++Changes; + SlotIndex Start = LIS.getMBBStartIdx(MBB); + VNInfo *VNI = LI->getNextValue(Start, 0, LIS.getVNInfoAllocator()); + VNI->setIsPHIDef(true); + DEBUG(dbgs() << " - BB#" << MBB->getNumber() + << " phi-def #" << VNI->id << " at " << Start << '\n'); + // We no longer need LI to be live-in. + LiveIn.erase(LiveIn.begin()+(i-1)); + // Blocks in LiveIn are either IdxMBB, or have a value live-through. + if (MBB == IdxMBB) + IdxVNI = VNI; + // Check if we need to update live-out info. + LiveOutMap::iterator I = LiveOutCache.find(MBB); + if (I == LiveOutCache.end() || I->second.second == Node) { + // We already have a live-out defined in MBB, so this must be IdxMBB. + assert(MBB == IdxMBB && "Adding phi-def to known live-out"); + LI->addRange(LiveRange(Start, Idx.getNextSlot(), VNI)); + } else { + // This phi-def is also live-out, so color the whole block. + LI->addRange(LiveRange(Start, LIS.getMBBEndIdx(MBB), VNI)); + I->second = LiveOutPair(VNI, Node); + } + } else if (IDomValue.first) { + // No phi-def here. Remember incoming value for IdxMBB. + if (MBB == IdxMBB) + IdxVNI = IDomValue.first; + // Propagate IDomValue if needed: + // MBB is live-out and doesn't define its own value. + LiveOutMap::iterator I = LiveOutCache.find(MBB); + if (I != LiveOutCache.end() && I->second.second != Node && + I->second.first != IDomValue.first) { + ++Changes; + I->second = IDomValue; + DEBUG(dbgs() << " - BB#" << MBB->getNumber() + << " idom valno #" << IDomValue.first->id + << " from BB#" << IDom->getBlock()->getNumber() << '\n'); + } } } + DEBUG(dbgs() << " - made " << Changes << " changes.\n"); + } while (Changes); - // No need to search the children, we found a dominating value. - IDFI.skipChildren(); - } + assert(IdxVNI && "Didn't find value for Idx"); - // The search should at least find a dominating value for IdxMBB. - assert(!DomValue.empty() && "Couldn't find a reaching definition"); +#ifndef NDEBUG + // Check the LiveOutCache invariants. + for (LiveOutMap::iterator I = LiveOutCache.begin(), E = LiveOutCache.end(); + I != E; ++I) { + assert(I->first && "Null MBB entry in cache"); + assert(I->second.first && "Null VNInfo in cache"); + assert(I->second.second && "Null DomTreeNode in cache"); + if (I->second.second->getBlock() == I->first) + continue; + for (MachineBasicBlock::pred_iterator PI = I->first->pred_begin(), + PE = I->first->pred_end(); PI != PE; ++PI) + assert(LiveOutCache.lookup(*PI) == I->second && "Bad invariant"); + } +#endif - // Since we went through the trouble of a full DFS visiting all reaching defs, - // the values in DomValue are now accurate. No more phi-defs are needed for - // these blocks, so we can color the live ranges. + // Since we went through the trouble of a full BFS visiting all reaching defs, + // the values in LiveIn are now accurate. No more phi-defs are needed + // for these blocks, so we can color the live ranges. // This makes the next mapValue call much faster. - VNInfo *IdxVNI = 0; - for (MBBValueMap::iterator I = DomValue.begin(), E = DomValue.end(); I != E; - ++I) { - MachineBasicBlock *MBB = I->first; - VNInfo *VNI = I->second; - SlotIndex Start = lis_.getMBBStartIdx(MBB); - if (MBB == IdxMBB) { - // Don't add full liveness to IdxMBB, stop at Idx. - if (Start != Idx) - li_.addRange(LiveRange(Start, Idx, VNI)); - // The caller had better add some liveness to IdxVNI, or it leaks. - IdxVNI = VNI; - } else - li_.addRange(LiveRange(Start, lis_.getMBBEndIdx(MBB), VNI)); + for (unsigned i = 0, e = LiveIn.size(); i != e; ++i) { + MachineBasicBlock *MBB = LiveIn[i]->getBlock(); + SlotIndex Start = LIS.getMBBStartIdx(MBB); + VNInfo *VNI = LiveOutCache.lookup(MBB).first; + + // Anything in LiveIn other than IdxMBB is live-through. + // In IdxMBB, we should stop at Idx unless the same value is live-out. + if (MBB == IdxMBB && IdxVNI != VNI) + LI->addRange(LiveRange(Start, Idx.getNextSlot(), IdxVNI)); + else + LI->addRange(LiveRange(Start, LIS.getMBBEndIdx(MBB), VNI)); } - assert(IdxVNI && "Didn't find value for Idx"); return IdxVNI; } -// extendTo - Find the last li_ value defined in MBB at or before Idx. The -// parentli_ is assumed to be live at Idx. Extend the live range to Idx. +#ifndef NDEBUG +void LiveIntervalMap::dumpCache() { + for (LiveOutMap::iterator I = LiveOutCache.begin(), E = LiveOutCache.end(); + I != E; ++I) { + assert(I->first && "Null MBB entry in cache"); + assert(I->second.first && "Null VNInfo in cache"); + assert(I->second.second && "Null DomTreeNode in cache"); + dbgs() << " cache: BB#" << I->first->getNumber() + << " has valno #" << I->second.first->id << " from BB#" + << I->second.second->getBlock()->getNumber() << ", preds"; + for (MachineBasicBlock::pred_iterator PI = I->first->pred_begin(), + PE = I->first->pred_end(); PI != PE; ++PI) + dbgs() << " BB#" << (*PI)->getNumber(); + dbgs() << '\n'; + } + dbgs() << " cache: " << LiveOutCache.size() << " entries.\n"; +} +#endif + +// extendTo - Find the last LI value defined in MBB at or before Idx. The +// ParentLI is assumed to be live at Idx. Extend the live range to Idx. // Return the found VNInfo, or NULL. -VNInfo *LiveIntervalMap::extendTo(MachineBasicBlock *MBB, SlotIndex Idx) { - LiveInterval::iterator I = std::upper_bound(li_.begin(), li_.end(), Idx); - if (I == li_.begin()) +VNInfo *LiveIntervalMap::extendTo(const MachineBasicBlock *MBB, SlotIndex Idx) { + assert(LI && "call reset first"); + LiveInterval::iterator I = std::upper_bound(LI->begin(), LI->end(), Idx); + if (I == LI->begin()) return 0; --I; - if (I->start < lis_.getMBBStartIdx(MBB)) + if (I->end <= LIS.getMBBStartIdx(MBB)) return 0; - if (I->end < Idx) - I->end = Idx; + if (I->end <= Idx) + I->end = Idx.getNextSlot(); return I->valno; } -// addSimpleRange - Add a simple range from parentli_ to li_. +// addSimpleRange - Add a simple range from ParentLI to LI. // ParentVNI must be live in the [Start;End) interval. void LiveIntervalMap::addSimpleRange(SlotIndex Start, SlotIndex End, const VNInfo *ParentVNI) { - VNInfo *VNI = mapValue(ParentVNI, Start); - // A simple mappoing is easy. - if (VNI->def == ParentVNI->def) { - li_.addRange(LiveRange(Start, End, VNI)); + assert(LI && "call reset first"); + bool simple; + VNInfo *VNI = mapValue(ParentVNI, Start, &simple); + // A simple mapping is easy. + if (simple) { + LI->addRange(LiveRange(Start, End, VNI)); return; } // ParentVNI is a complex value. We must map per MBB. - MachineFunction::iterator MBB = lis_.getMBBFromIndex(Start); - MachineFunction::iterator MBBE = lis_.getMBBFromIndex(End); + MachineFunction::iterator MBB = LIS.getMBBFromIndex(Start); + MachineFunction::iterator MBBE = LIS.getMBBFromIndex(End.getPrevSlot()); if (MBB == MBBE) { - li_.addRange(LiveRange(Start, End, VNI)); + LI->addRange(LiveRange(Start, End, VNI)); return; } // First block. - li_.addRange(LiveRange(Start, lis_.getMBBEndIdx(MBB), VNI)); + LI->addRange(LiveRange(Start, LIS.getMBBEndIdx(MBB), VNI)); // Run sequence of full blocks. for (++MBB; MBB != MBBE; ++MBB) { - Start = lis_.getMBBStartIdx(MBB); - li_.addRange(LiveRange(Start, lis_.getMBBEndIdx(MBB), - mapValue(ParentVNI, Start))); + Start = LIS.getMBBStartIdx(MBB); + LI->addRange(LiveRange(Start, LIS.getMBBEndIdx(MBB), + mapValue(ParentVNI, Start))); } // Final block. - Start = lis_.getMBBStartIdx(MBB); + Start = LIS.getMBBStartIdx(MBB); if (Start != End) - li_.addRange(LiveRange(Start, End, mapValue(ParentVNI, Start))); + LI->addRange(LiveRange(Start, End, mapValue(ParentVNI, Start))); } -/// addRange - Add live ranges to li_ where [Start;End) intersects parentli_. +/// addRange - Add live ranges to LI where [Start;End) intersects ParentLI. /// All needed values whose def is not inside [Start;End) must be defined /// beforehand so mapValue will work. void LiveIntervalMap::addRange(SlotIndex Start, SlotIndex End) { - LiveInterval::const_iterator B = parentli_.begin(), E = parentli_.end(); + assert(LI && "call reset first"); + LiveInterval::const_iterator B = ParentLI.begin(), E = ParentLI.end(); LiveInterval::const_iterator I = std::lower_bound(B, E, Start); // Check if --I begins before Start and overlaps. @@ -575,403 +539,374 @@ void LiveIntervalMap::addRange(SlotIndex Start, SlotIndex End) { addSimpleRange(I->start, std::min(End, I->end), I->valno); } + //===----------------------------------------------------------------------===// // Split Editor //===----------------------------------------------------------------------===// /// Create a new SplitEditor for editing the LiveInterval analyzed by SA. -SplitEditor::SplitEditor(SplitAnalysis &sa, LiveIntervals &lis, VirtRegMap &vrm, - SmallVectorImpl<LiveInterval*> &intervals) - : sa_(sa), lis_(lis), vrm_(vrm), - mri_(vrm.getMachineFunction().getRegInfo()), - tii_(*vrm.getMachineFunction().getTarget().getInstrInfo()), - curli_(sa_.getCurLI()), - dupli_(0), openli_(0), - intervals_(intervals), - firstInterval(intervals_.size()) +SplitEditor::SplitEditor(SplitAnalysis &sa, + LiveIntervals &lis, + VirtRegMap &vrm, + MachineDominatorTree &mdt, + LiveRangeEdit &edit) + : SA(sa), LIS(lis), VRM(vrm), + MRI(vrm.getMachineFunction().getRegInfo()), + MDT(mdt), + TII(*vrm.getMachineFunction().getTarget().getInstrInfo()), + TRI(*vrm.getMachineFunction().getTarget().getRegisterInfo()), + Edit(edit), + OpenIdx(0), + RegAssign(Allocator) { - assert(curli_ && "SplitEditor created from empty SplitAnalysis"); - - // Make sure curli_ is assigned a stack slot, so all our intervals get the - // same slot as curli_. - if (vrm_.getStackSlot(curli_->reg) == VirtRegMap::NO_STACK_SLOT) - vrm_.assignVirt2StackSlot(curli_->reg); - + // We don't need an AliasAnalysis since we will only be performing + // cheap-as-a-copy remats anyway. + Edit.anyRematerializable(LIS, TII, 0); } -LiveInterval *SplitEditor::createInterval() { - unsigned curli = sa_.getCurLI()->reg; - unsigned Reg = mri_.createVirtualRegister(mri_.getRegClass(curli)); - LiveInterval &Intv = lis_.getOrCreateInterval(Reg); - vrm_.grow(); - vrm_.assignVirt2StackSlot(Reg, vrm_.getStackSlot(curli)); - return &Intv; +void SplitEditor::dump() const { + if (RegAssign.empty()) { + dbgs() << " empty\n"; + return; + } + + for (RegAssignMap::const_iterator I = RegAssign.begin(); I.valid(); ++I) + dbgs() << " [" << I.start() << ';' << I.stop() << "):" << I.value(); + dbgs() << '\n'; } -LiveInterval *SplitEditor::getDupLI() { - if (!dupli_) { - // Create an interval for dupli that is a copy of curli. - dupli_ = createInterval(); - dupli_->Copy(*curli_, &mri_, lis_.getVNInfoAllocator()); +VNInfo *SplitEditor::defFromParent(unsigned RegIdx, + VNInfo *ParentVNI, + SlotIndex UseIdx, + MachineBasicBlock &MBB, + MachineBasicBlock::iterator I) { + MachineInstr *CopyMI = 0; + SlotIndex Def; + LiveInterval *LI = Edit.get(RegIdx); + + // Attempt cheap-as-a-copy rematerialization. + LiveRangeEdit::Remat RM(ParentVNI); + if (Edit.canRematerializeAt(RM, UseIdx, true, LIS)) { + Def = Edit.rematerializeAt(MBB, I, LI->reg, RM, LIS, TII, TRI); + } else { + // Can't remat, just insert a copy from parent. + CopyMI = BuildMI(MBB, I, DebugLoc(), TII.get(TargetOpcode::COPY), LI->reg) + .addReg(Edit.getReg()); + Def = LIS.InsertMachineInstrInMaps(CopyMI).getDefIndex(); } - return dupli_; -} -VNInfo *SplitEditor::mapValue(const VNInfo *curliVNI) { - VNInfo *&VNI = valueMap_[curliVNI]; - if (!VNI) - VNI = openli_->createValueCopy(curliVNI, lis_.getVNInfoAllocator()); - return VNI; -} + // Define the value in Reg. + VNInfo *VNI = LIMappers[RegIdx].defValue(ParentVNI, Def); + VNI->setCopy(CopyMI); -/// Insert a COPY instruction curli -> li. Allocate a new value from li -/// defined by the COPY. Note that rewrite() will deal with the curli -/// register, so this function can be used to copy from any interval - openli, -/// curli, or dupli. -VNInfo *SplitEditor::insertCopy(LiveInterval &LI, - MachineBasicBlock &MBB, - MachineBasicBlock::iterator I) { - MachineInstr *MI = BuildMI(MBB, I, DebugLoc(), tii_.get(TargetOpcode::COPY), - LI.reg).addReg(curli_->reg); - SlotIndex DefIdx = lis_.InsertMachineInstrInMaps(MI).getDefIndex(); - return LI.getNextValue(DefIdx, MI, true, lis_.getVNInfoAllocator()); + // Add minimal liveness for the new value. + Edit.get(RegIdx)->addRange(LiveRange(Def, Def.getNextSlot(), VNI)); + return VNI; } /// Create a new virtual register and live interval. void SplitEditor::openIntv() { - assert(!openli_ && "Previous LI not closed before openIntv"); - openli_ = createInterval(); - intervals_.push_back(openli_); - liveThrough_ = false; -} + assert(!OpenIdx && "Previous LI not closed before openIntv"); -/// enterIntvBefore - Enter openli before the instruction at Idx. If curli is -/// not live before Idx, a COPY is not inserted. -void SplitEditor::enterIntvBefore(SlotIndex Idx) { - assert(openli_ && "openIntv not called before enterIntvBefore"); - - // Copy from curli_ if it is live. - if (VNInfo *CurVNI = curli_->getVNInfoAt(Idx.getUseIndex())) { - MachineInstr *MI = lis_.getInstructionFromIndex(Idx); - assert(MI && "enterIntvBefore called with invalid index"); - VNInfo *VNI = insertCopy(*openli_, *MI->getParent(), MI); - openli_->addRange(LiveRange(VNI->def, Idx.getDefIndex(), VNI)); - - // Make sure CurVNI is properly mapped. - VNInfo *&mapVNI = valueMap_[CurVNI]; - // We dont have SSA update yet, so only one entry per value is allowed. - assert(!mapVNI && "enterIntvBefore called more than once for the same value"); - mapVNI = VNI; + // Create the complement as index 0. + if (Edit.empty()) { + Edit.create(MRI, LIS, VRM); + LIMappers.push_back(LiveIntervalMap(LIS, MDT, Edit.getParent())); + LIMappers.back().reset(Edit.get(0)); } - DEBUG(dbgs() << " enterIntvBefore " << Idx << ": " << *openli_ << '\n'); -} -/// enterIntvAtEnd - Enter openli at the end of MBB. -/// PhiMBB is a successor inside openli where a PHI value is created. -/// Currently, all entries must share the same PhiMBB. -void SplitEditor::enterIntvAtEnd(MachineBasicBlock &A, MachineBasicBlock &B) { - assert(openli_ && "openIntv not called before enterIntvAtEnd"); - - SlotIndex EndA = lis_.getMBBEndIdx(&A); - VNInfo *CurVNIA = curli_->getVNInfoAt(EndA.getPrevIndex()); - if (!CurVNIA) { - DEBUG(dbgs() << " enterIntvAtEnd, curli not live out of BB#" - << A.getNumber() << ".\n"); - return; - } + // Create the open interval. + OpenIdx = Edit.size(); + Edit.create(MRI, LIS, VRM); + LIMappers.push_back(LiveIntervalMap(LIS, MDT, Edit.getParent())); + LIMappers[OpenIdx].reset(Edit.get(OpenIdx)); +} - // Add a phi kill value and live range out of A. - VNInfo *VNIA = insertCopy(*openli_, A, A.getFirstTerminator()); - openli_->addRange(LiveRange(VNIA->def, EndA, VNIA)); - - // FIXME: If this is the only entry edge, we don't need the extra PHI value. - // FIXME: If there are multiple entry blocks (so not a loop), we need proper - // SSA update. - - // Now look at the start of B. - SlotIndex StartB = lis_.getMBBStartIdx(&B); - SlotIndex EndB = lis_.getMBBEndIdx(&B); - const LiveRange *CurB = curli_->getLiveRangeContaining(StartB); - if (!CurB) { - DEBUG(dbgs() << " enterIntvAtEnd: curli not live in to BB#" - << B.getNumber() << ".\n"); - return; +SlotIndex SplitEditor::enterIntvBefore(SlotIndex Idx) { + assert(OpenIdx && "openIntv not called before enterIntvBefore"); + DEBUG(dbgs() << " enterIntvBefore " << Idx); + Idx = Idx.getBaseIndex(); + VNInfo *ParentVNI = Edit.getParent().getVNInfoAt(Idx); + if (!ParentVNI) { + DEBUG(dbgs() << ": not live\n"); + return Idx; } + DEBUG(dbgs() << ": valno " << ParentVNI->id << '\n'); + MachineInstr *MI = LIS.getInstructionFromIndex(Idx); + assert(MI && "enterIntvBefore called with invalid index"); - VNInfo *VNIB = openli_->getVNInfoAt(StartB); - if (!VNIB) { - // Create a phi value. - VNIB = openli_->getNextValue(SlotIndex(StartB, true), 0, false, - lis_.getVNInfoAllocator()); - VNIB->setIsPHIDef(true); - VNInfo *&mapVNI = valueMap_[CurB->valno]; - if (mapVNI) { - // Multiple copies - must create PHI value. - abort(); - } else { - // This is the first copy of dupLR. Mark the mapping. - mapVNI = VNIB; - } + VNInfo *VNI = defFromParent(OpenIdx, ParentVNI, Idx, *MI->getParent(), MI); + return VNI->def; +} +SlotIndex SplitEditor::enterIntvAtEnd(MachineBasicBlock &MBB) { + assert(OpenIdx && "openIntv not called before enterIntvAtEnd"); + SlotIndex End = LIS.getMBBEndIdx(&MBB); + SlotIndex Last = End.getPrevSlot(); + DEBUG(dbgs() << " enterIntvAtEnd BB#" << MBB.getNumber() << ", " << Last); + VNInfo *ParentVNI = Edit.getParent().getVNInfoAt(Last); + if (!ParentVNI) { + DEBUG(dbgs() << ": not live\n"); + return End; } - - DEBUG(dbgs() << " enterIntvAtEnd: " << *openli_ << '\n'); + DEBUG(dbgs() << ": valno " << ParentVNI->id); + VNInfo *VNI = defFromParent(OpenIdx, ParentVNI, Last, MBB, + LIS.getLastSplitPoint(Edit.getParent(), &MBB)); + RegAssign.insert(VNI->def, End, OpenIdx); + DEBUG(dump()); + return VNI->def; } -/// useIntv - indicate that all instructions in MBB should use openli. +/// useIntv - indicate that all instructions in MBB should use OpenLI. void SplitEditor::useIntv(const MachineBasicBlock &MBB) { - useIntv(lis_.getMBBStartIdx(&MBB), lis_.getMBBEndIdx(&MBB)); + useIntv(LIS.getMBBStartIdx(&MBB), LIS.getMBBEndIdx(&MBB)); } void SplitEditor::useIntv(SlotIndex Start, SlotIndex End) { - assert(openli_ && "openIntv not called before useIntv"); + assert(OpenIdx && "openIntv not called before useIntv"); + DEBUG(dbgs() << " useIntv [" << Start << ';' << End << "):"); + RegAssign.insert(Start, End, OpenIdx); + DEBUG(dump()); +} - // Map the curli values from the interval into openli_ - LiveInterval::const_iterator B = curli_->begin(), E = curli_->end(); - LiveInterval::const_iterator I = std::lower_bound(B, E, Start); +SlotIndex SplitEditor::leaveIntvAfter(SlotIndex Idx) { + assert(OpenIdx && "openIntv not called before leaveIntvAfter"); + DEBUG(dbgs() << " leaveIntvAfter " << Idx); - if (I != B) { - --I; - // I begins before Start, but overlaps. - if (I->end > Start) - openli_->addRange(LiveRange(Start, std::min(End, I->end), - mapValue(I->valno))); - ++I; + // The interval must be live beyond the instruction at Idx. + Idx = Idx.getBoundaryIndex(); + VNInfo *ParentVNI = Edit.getParent().getVNInfoAt(Idx); + if (!ParentVNI) { + DEBUG(dbgs() << ": not live\n"); + return Idx.getNextSlot(); } + DEBUG(dbgs() << ": valno " << ParentVNI->id << '\n'); - // The remaining ranges begin after Start. - for (;I != E && I->start < End; ++I) - openli_->addRange(LiveRange(I->start, std::min(End, I->end), - mapValue(I->valno))); - DEBUG(dbgs() << " use [" << Start << ';' << End << "): " << *openli_ - << '\n'); + MachineInstr *MI = LIS.getInstructionFromIndex(Idx); + assert(MI && "No instruction at index"); + VNInfo *VNI = defFromParent(0, ParentVNI, Idx, *MI->getParent(), + llvm::next(MachineBasicBlock::iterator(MI))); + return VNI->def; } -/// leaveIntvAfter - Leave openli after the instruction at Idx. -void SplitEditor::leaveIntvAfter(SlotIndex Idx) { - assert(openli_ && "openIntv not called before leaveIntvAfter"); +SlotIndex SplitEditor::leaveIntvBefore(SlotIndex Idx) { + assert(OpenIdx && "openIntv not called before leaveIntvBefore"); + DEBUG(dbgs() << " leaveIntvBefore " << Idx); - const LiveRange *CurLR = curli_->getLiveRangeContaining(Idx.getDefIndex()); - if (!CurLR || CurLR->end <= Idx.getBoundaryIndex()) { - DEBUG(dbgs() << " leaveIntvAfter " << Idx << ": not live\n"); - return; + // The interval must be live into the instruction at Idx. + Idx = Idx.getBoundaryIndex(); + VNInfo *ParentVNI = Edit.getParent().getVNInfoAt(Idx); + if (!ParentVNI) { + DEBUG(dbgs() << ": not live\n"); + return Idx.getNextSlot(); } + DEBUG(dbgs() << ": valno " << ParentVNI->id << '\n'); - // Was this value of curli live through openli? - if (!openli_->liveAt(CurLR->valno->def)) { - DEBUG(dbgs() << " leaveIntvAfter " << Idx << ": using external value\n"); - liveThrough_ = true; - return; - } - - // We are going to insert a back copy, so we must have a dupli_. - LiveRange *DupLR = getDupLI()->getLiveRangeContaining(Idx.getDefIndex()); - assert(DupLR && "dupli not live into black, but curli is?"); - - // Insert the COPY instruction. - MachineBasicBlock::iterator I = lis_.getInstructionFromIndex(Idx); - MachineInstr *MI = BuildMI(*I->getParent(), llvm::next(I), I->getDebugLoc(), - tii_.get(TargetOpcode::COPY), dupli_->reg) - .addReg(openli_->reg); - SlotIndex CopyIdx = lis_.InsertMachineInstrInMaps(MI).getDefIndex(); - openli_->addRange(LiveRange(Idx.getDefIndex(), CopyIdx, - mapValue(CurLR->valno))); - DupLR->valno->def = CopyIdx; - DEBUG(dbgs() << " leaveIntvAfter " << Idx << ": " << *openli_ << '\n'); + MachineInstr *MI = LIS.getInstructionFromIndex(Idx); + assert(MI && "No instruction at index"); + VNInfo *VNI = defFromParent(0, ParentVNI, Idx, *MI->getParent(), MI); + return VNI->def; } -/// leaveIntvAtTop - Leave the interval at the top of MBB. -/// Currently, only one value can leave the interval. -void SplitEditor::leaveIntvAtTop(MachineBasicBlock &MBB) { - assert(openli_ && "openIntv not called before leaveIntvAtTop"); - - SlotIndex Start = lis_.getMBBStartIdx(&MBB); - const LiveRange *CurLR = curli_->getLiveRangeContaining(Start); - - // Is curli even live-in to MBB? - if (!CurLR) { - DEBUG(dbgs() << " leaveIntvAtTop at " << Start << ": not live\n"); - return; - } - - // Is curli defined by PHI at the beginning of MBB? - bool isPHIDef = CurLR->valno->isPHIDef() && - CurLR->valno->def.getBaseIndex() == Start; +SlotIndex SplitEditor::leaveIntvAtTop(MachineBasicBlock &MBB) { + assert(OpenIdx && "openIntv not called before leaveIntvAtTop"); + SlotIndex Start = LIS.getMBBStartIdx(&MBB); + DEBUG(dbgs() << " leaveIntvAtTop BB#" << MBB.getNumber() << ", " << Start); - // If MBB is using a value of curli that was defined outside the openli range, - // we don't want to copy it back here. - if (!isPHIDef && !openli_->liveAt(CurLR->valno->def)) { - DEBUG(dbgs() << " leaveIntvAtTop at " << Start - << ": using external value\n"); - liveThrough_ = true; - return; + VNInfo *ParentVNI = Edit.getParent().getVNInfoAt(Start); + if (!ParentVNI) { + DEBUG(dbgs() << ": not live\n"); + return Start; } - // We are going to insert a back copy, so we must have a dupli_. - LiveRange *DupLR = getDupLI()->getLiveRangeContaining(Start); - assert(DupLR && "dupli not live into black, but curli is?"); - - // Insert the COPY instruction. - MachineInstr *MI = BuildMI(MBB, MBB.begin(), DebugLoc(), - tii_.get(TargetOpcode::COPY), dupli_->reg) - .addReg(openli_->reg); - SlotIndex Idx = lis_.InsertMachineInstrInMaps(MI).getDefIndex(); - - // Adjust dupli and openli values. - if (isPHIDef) { - // dupli was already a PHI on entry to MBB. Simply insert an openli PHI, - // and shift the dupli def down to the COPY. - VNInfo *VNI = openli_->getNextValue(SlotIndex(Start, true), 0, false, - lis_.getVNInfoAllocator()); - VNI->setIsPHIDef(true); - openli_->addRange(LiveRange(VNI->def, Idx, VNI)); - - dupli_->removeRange(Start, Idx); - DupLR->valno->def = Idx; - DupLR->valno->setIsPHIDef(false); - } else { - // The dupli value was defined somewhere inside the openli range. - DEBUG(dbgs() << " leaveIntvAtTop source value defined at " - << DupLR->valno->def << "\n"); - // FIXME: We may not need a PHI here if all predecessors have the same - // value. - VNInfo *VNI = openli_->getNextValue(SlotIndex(Start, true), 0, false, - lis_.getVNInfoAllocator()); - VNI->setIsPHIDef(true); - openli_->addRange(LiveRange(VNI->def, Idx, VNI)); - - // FIXME: What if DupLR->valno is used by multiple exits? SSA Update. - - // closeIntv is going to remove the superfluous live ranges. - DupLR->valno->def = Idx; - DupLR->valno->setIsPHIDef(false); - } + VNInfo *VNI = defFromParent(0, ParentVNI, Start, MBB, + MBB.SkipPHIsAndLabels(MBB.begin())); + RegAssign.insert(Start, VNI->def, OpenIdx); + DEBUG(dump()); + return VNI->def; +} - DEBUG(dbgs() << " leaveIntvAtTop at " << Idx << ": " << *openli_ << '\n'); +void SplitEditor::overlapIntv(SlotIndex Start, SlotIndex End) { + assert(OpenIdx && "openIntv not called before overlapIntv"); + assert(Edit.getParent().getVNInfoAt(Start) == + Edit.getParent().getVNInfoAt(End.getPrevSlot()) && + "Parent changes value in extended range"); + assert(Edit.get(0)->getVNInfoAt(Start) && "Start must come from leaveIntv*"); + assert(LIS.getMBBFromIndex(Start) == LIS.getMBBFromIndex(End) && + "Range cannot span basic blocks"); + + // Treat this as useIntv() for now. The complement interval will be extended + // as needed by mapValue(). + DEBUG(dbgs() << " overlapIntv [" << Start << ';' << End << "):"); + RegAssign.insert(Start, End, OpenIdx); + DEBUG(dump()); } /// closeIntv - Indicate that we are done editing the currently open /// LiveInterval, and ranges can be trimmed. void SplitEditor::closeIntv() { - assert(openli_ && "openIntv not called before closeIntv"); - - DEBUG(dbgs() << " closeIntv cleaning up\n"); - DEBUG(dbgs() << " open " << *openli_ << '\n'); - - if (liveThrough_) { - DEBUG(dbgs() << " value live through region, leaving dupli as is.\n"); - } else { - // live out with copies inserted, or killed by region. Either way we need to - // remove the overlapping region from dupli. - getDupLI(); - for (LiveInterval::iterator I = openli_->begin(), E = openli_->end(); - I != E; ++I) { - dupli_->removeRange(I->start, I->end); - } - // FIXME: A block branching to the entry block may also branch elsewhere - // curli is live. We need both openli and curli to be live in that case. - DEBUG(dbgs() << " dup2 " << *dupli_ << '\n'); - } - openli_ = 0; - valueMap_.clear(); + assert(OpenIdx && "openIntv not called before closeIntv"); + OpenIdx = 0; } -/// rewrite - after all the new live ranges have been created, rewrite -/// instructions using curli to use the new intervals. -void SplitEditor::rewrite() { - assert(!openli_ && "Previous LI not closed before rewrite"); - const LiveInterval *curli = sa_.getCurLI(); - for (MachineRegisterInfo::reg_iterator RI = mri_.reg_begin(curli->reg), - RE = mri_.reg_end(); RI != RE;) { +/// rewriteAssigned - Rewrite all uses of Edit.getReg(). +void SplitEditor::rewriteAssigned() { + for (MachineRegisterInfo::reg_iterator RI = MRI.reg_begin(Edit.getReg()), + RE = MRI.reg_end(); RI != RE;) { MachineOperand &MO = RI.getOperand(); MachineInstr *MI = MO.getParent(); ++RI; + // LiveDebugVariables should have handled all DBG_VALUE instructions. if (MI->isDebugValue()) { DEBUG(dbgs() << "Zapping " << *MI); - // FIXME: We can do much better with debug values. MO.setReg(0); continue; } - SlotIndex Idx = lis_.getInstructionIndex(MI); - Idx = MO.isUse() ? Idx.getUseIndex() : Idx.getDefIndex(); - LiveInterval *LI = dupli_; - for (unsigned i = firstInterval, e = intervals_.size(); i != e; ++i) { - LiveInterval *testli = intervals_[i]; - if (testli->liveAt(Idx)) { - LI = testli; - break; - } - } - if (LI) { - MO.setReg(LI->reg); - sa_.removeUse(MI); - DEBUG(dbgs() << " rewrite " << Idx << '\t' << *MI); - } - } - // dupli_ goes in last, after rewriting. - if (dupli_) { - if (dupli_->empty()) { - DEBUG(dbgs() << " dupli became empty?\n"); - lis_.removeInterval(dupli_->reg); - dupli_ = 0; - } else { - dupli_->RenumberValues(lis_); - intervals_.push_back(dupli_); + // <undef> operands don't really read the register, so just assign them to + // the complement. + if (MO.isUse() && MO.isUndef()) { + MO.setReg(Edit.get(0)->reg); + continue; } + + SlotIndex Idx = LIS.getInstructionIndex(MI); + Idx = MO.isUse() ? Idx.getUseIndex() : Idx.getDefIndex(); + + // Rewrite to the mapped register at Idx. + unsigned RegIdx = RegAssign.lookup(Idx); + MO.setReg(Edit.get(RegIdx)->reg); + DEBUG(dbgs() << " rewr BB#" << MI->getParent()->getNumber() << '\t' + << Idx << ':' << RegIdx << '\t' << *MI); + + // Extend liveness to Idx. + const VNInfo *ParentVNI = Edit.getParent().getVNInfoAt(Idx); + LIMappers[RegIdx].mapValue(ParentVNI, Idx); } +} - // Calculate spill weight and allocation hints for new intervals. - VirtRegAuxInfo vrai(vrm_.getMachineFunction(), lis_, sa_.loops_); - for (unsigned i = firstInterval, e = intervals_.size(); i != e; ++i) { - LiveInterval &li = *intervals_[i]; - vrai.CalculateRegClass(li.reg); - vrai.CalculateWeightAndHint(li); - DEBUG(dbgs() << " new interval " << mri_.getRegClass(li.reg)->getName() - << ":" << li << '\n'); +/// rewriteSplit - Rewrite uses of Intvs[0] according to the ConEQ mapping. +void SplitEditor::rewriteComponents(const SmallVectorImpl<LiveInterval*> &Intvs, + const ConnectedVNInfoEqClasses &ConEq) { + for (MachineRegisterInfo::reg_iterator RI = MRI.reg_begin(Intvs[0]->reg), + RE = MRI.reg_end(); RI != RE;) { + MachineOperand &MO = RI.getOperand(); + MachineInstr *MI = MO.getParent(); + ++RI; + if (MO.isUse() && MO.isUndef()) + continue; + // DBG_VALUE instructions should have been eliminated earlier. + SlotIndex Idx = LIS.getInstructionIndex(MI); + Idx = MO.isUse() ? Idx.getUseIndex() : Idx.getDefIndex(); + DEBUG(dbgs() << " rewr BB#" << MI->getParent()->getNumber() << '\t' + << Idx << ':'); + const VNInfo *VNI = Intvs[0]->getVNInfoAt(Idx); + assert(VNI && "Interval not live at use."); + MO.setReg(Intvs[ConEq.getEqClass(VNI)]->reg); + DEBUG(dbgs() << VNI->id << '\t' << *MI); } } +void SplitEditor::finish() { + assert(OpenIdx == 0 && "Previous LI not closed before rewrite"); -//===----------------------------------------------------------------------===// -// Loop Splitting -//===----------------------------------------------------------------------===// + // At this point, the live intervals in Edit contain VNInfos corresponding to + // the inserted copies. -bool SplitEditor::splitAroundLoop(const MachineLoop *Loop) { - SplitAnalysis::LoopBlocks Blocks; - sa_.getLoopBlocks(Loop, Blocks); + // Add the original defs from the parent interval. + for (LiveInterval::const_vni_iterator I = Edit.getParent().vni_begin(), + E = Edit.getParent().vni_end(); I != E; ++I) { + const VNInfo *ParentVNI = *I; + if (ParentVNI->isUnused()) + continue; + LiveIntervalMap &LIM = LIMappers[RegAssign.lookup(ParentVNI->def)]; + VNInfo *VNI = LIM.defValue(ParentVNI, ParentVNI->def); + LIM.getLI()->addRange(LiveRange(ParentVNI->def, + ParentVNI->def.getNextSlot(), VNI)); + // Mark all values as complex to force liveness computation. + // This should really only be necessary for remat victims, but we are lazy. + LIM.markComplexMapped(ParentVNI); + } - // Break critical edges as needed. - SplitAnalysis::BlockPtrSet CriticalExits; - sa_.getCriticalExits(Blocks, CriticalExits); - assert(CriticalExits.empty() && "Cannot break critical exits yet"); +#ifndef NDEBUG + // Every new interval must have a def by now, otherwise the split is bogus. + for (LiveRangeEdit::iterator I = Edit.begin(), E = Edit.end(); I != E; ++I) + assert((*I)->hasAtLeastOneValue() && "Split interval has no value"); +#endif + + // FIXME: Don't recompute the liveness of all values, infer it from the + // overlaps between the parent live interval and RegAssign. + // The mapValue algorithm is only necessary when: + // - The parent value maps to multiple defs, and new phis are needed, or + // - The value has been rematerialized before some uses, and we want to + // minimize the live range so it only reaches the remaining uses. + // All other values have simple liveness that can be computed from RegAssign + // and the parent live interval. + + // Extend live ranges to be live-out for successor PHI values. + for (LiveInterval::const_vni_iterator I = Edit.getParent().vni_begin(), + E = Edit.getParent().vni_end(); I != E; ++I) { + const VNInfo *PHIVNI = *I; + if (PHIVNI->isUnused() || !PHIVNI->isPHIDef()) + continue; + unsigned RegIdx = RegAssign.lookup(PHIVNI->def); + LiveIntervalMap &LIM = LIMappers[RegIdx]; + MachineBasicBlock *MBB = LIS.getMBBFromIndex(PHIVNI->def); + DEBUG(dbgs() << " map phi in BB#" << MBB->getNumber() << '@' << PHIVNI->def + << " -> " << RegIdx << '\n'); + for (MachineBasicBlock::pred_iterator PI = MBB->pred_begin(), + PE = MBB->pred_end(); PI != PE; ++PI) { + SlotIndex End = LIS.getMBBEndIdx(*PI).getPrevSlot(); + DEBUG(dbgs() << " pred BB#" << (*PI)->getNumber() << '@' << End); + // The predecessor may not have a live-out value. That is OK, like an + // undef PHI operand. + if (VNInfo *VNI = Edit.getParent().getVNInfoAt(End)) { + DEBUG(dbgs() << " has parent valno #" << VNI->id << " live out\n"); + assert(RegAssign.lookup(End) == RegIdx && + "Different register assignment in phi predecessor"); + LIM.mapValue(VNI, End); + } + else + DEBUG(dbgs() << " is not live-out\n"); + } + DEBUG(dbgs() << " " << *LIM.getLI() << '\n'); + } - // Create new live interval for the loop. - openIntv(); + // Rewrite instructions. + rewriteAssigned(); - // Insert copies in the predecessors. - for (SplitAnalysis::BlockPtrSet::iterator I = Blocks.Preds.begin(), - E = Blocks.Preds.end(); I != E; ++I) { - MachineBasicBlock &MBB = const_cast<MachineBasicBlock&>(**I); - enterIntvAtEnd(MBB, *Loop->getHeader()); - } + // FIXME: Delete defs that were rematted everywhere. - // Switch all loop blocks. - for (SplitAnalysis::BlockPtrSet::iterator I = Blocks.Loop.begin(), - E = Blocks.Loop.end(); I != E; ++I) - useIntv(**I); + // Get rid of unused values and set phi-kill flags. + for (LiveRangeEdit::iterator I = Edit.begin(), E = Edit.end(); I != E; ++I) + (*I)->RenumberValues(LIS); - // Insert back copies in the exit blocks. - for (SplitAnalysis::BlockPtrSet::iterator I = Blocks.Exits.begin(), - E = Blocks.Exits.end(); I != E; ++I) { - MachineBasicBlock &MBB = const_cast<MachineBasicBlock&>(**I); - leaveIntvAtTop(MBB); + // Now check if any registers were separated into multiple components. + ConnectedVNInfoEqClasses ConEQ(LIS); + for (unsigned i = 0, e = Edit.size(); i != e; ++i) { + // Don't use iterators, they are invalidated by create() below. + LiveInterval *li = Edit.get(i); + unsigned NumComp = ConEQ.Classify(li); + if (NumComp <= 1) + continue; + DEBUG(dbgs() << " " << NumComp << " components: " << *li << '\n'); + SmallVector<LiveInterval*, 8> dups; + dups.push_back(li); + for (unsigned i = 1; i != NumComp; ++i) + dups.push_back(&Edit.create(MRI, LIS, VRM)); + rewriteComponents(dups, ConEQ); + ConEQ.Distribute(&dups[0]); } - // Done. - closeIntv(); - rewrite(); - return dupli_; + // Calculate spill weight and allocation hints for new intervals. + VirtRegAuxInfo vrai(VRM.getMachineFunction(), LIS, SA.Loops); + for (LiveRangeEdit::iterator I = Edit.begin(), E = Edit.end(); I != E; ++I){ + LiveInterval &li = **I; + vrai.CalculateRegClass(li.reg); + vrai.CalculateWeightAndHint(li); + DEBUG(dbgs() << " new interval " << MRI.getRegClass(li.reg)->getName() + << ":" << li << '\n'); + } } @@ -979,45 +914,50 @@ bool SplitEditor::splitAroundLoop(const MachineLoop *Loop) { // Single Block Splitting //===----------------------------------------------------------------------===// -/// splitSingleBlocks - Split curli into a separate live interval inside each -/// basic block in Blocks. Return true if curli has been completely replaced, -/// false if curli is still intact, and needs to be spilled or split further. -bool SplitEditor::splitSingleBlocks(const SplitAnalysis::BlockPtrSet &Blocks) { - DEBUG(dbgs() << " splitSingleBlocks for " << Blocks.size() << " blocks.\n"); - // Determine the first and last instruction using curli in each block. - typedef std::pair<SlotIndex,SlotIndex> IndexPair; - typedef DenseMap<const MachineBasicBlock*,IndexPair> IndexPairMap; - IndexPairMap MBBRange; - for (SplitAnalysis::InstrPtrSet::const_iterator I = sa_.usingInstrs_.begin(), - E = sa_.usingInstrs_.end(); I != E; ++I) { - const MachineBasicBlock *MBB = (*I)->getParent(); - if (!Blocks.count(MBB)) +/// getMultiUseBlocks - if CurLI has more than one use in a basic block, it +/// may be an advantage to split CurLI for the duration of the block. +bool SplitAnalysis::getMultiUseBlocks(BlockPtrSet &Blocks) { + // If CurLI is local to one block, there is no point to splitting it. + if (LiveBlocks.size() <= 1) + return false; + // Add blocks with multiple uses. + for (unsigned i = 0, e = LiveBlocks.size(); i != e; ++i) { + const BlockInfo &BI = LiveBlocks[i]; + if (!BI.Uses) continue; - SlotIndex Idx = lis_.getInstructionIndex(*I); - DEBUG(dbgs() << " BB#" << MBB->getNumber() << '\t' << Idx << '\t' << **I); - IndexPair &IP = MBBRange[MBB]; - if (!IP.first.isValid() || Idx < IP.first) - IP.first = Idx; - if (!IP.second.isValid() || Idx > IP.second) - IP.second = Idx; + unsigned Instrs = UsingBlocks.lookup(BI.MBB); + if (Instrs <= 1) + continue; + if (Instrs == 2 && BI.LiveIn && BI.LiveOut && !BI.LiveThrough) + continue; + Blocks.insert(BI.MBB); } + return !Blocks.empty(); +} + +/// splitSingleBlocks - Split CurLI into a separate live interval inside each +/// basic block in Blocks. +void SplitEditor::splitSingleBlocks(const SplitAnalysis::BlockPtrSet &Blocks) { + DEBUG(dbgs() << " splitSingleBlocks for " << Blocks.size() << " blocks.\n"); - // Create a new interval for each block. - for (SplitAnalysis::BlockPtrSet::const_iterator I = Blocks.begin(), - E = Blocks.end(); I != E; ++I) { - IndexPair &IP = MBBRange[*I]; - DEBUG(dbgs() << " splitting for BB#" << (*I)->getNumber() << ": [" - << IP.first << ';' << IP.second << ")\n"); - assert(IP.first.isValid() && IP.second.isValid()); + for (unsigned i = 0, e = SA.LiveBlocks.size(); i != e; ++i) { + const SplitAnalysis::BlockInfo &BI = SA.LiveBlocks[i]; + if (!BI.Uses || !Blocks.count(BI.MBB)) + continue; openIntv(); - enterIntvBefore(IP.first); - useIntv(IP.first.getBaseIndex(), IP.second.getBoundaryIndex()); - leaveIntvAfter(IP.second); + SlotIndex SegStart = enterIntvBefore(BI.FirstUse); + if (BI.LastUse < BI.LastSplitPoint) { + useIntv(SegStart, leaveIntvAfter(BI.LastUse)); + } else { + // THe last use os after tha last valid split point. + SlotIndex SegStop = leaveIntvBefore(BI.LastSplitPoint); + useIntv(SegStart, SegStop); + overlapIntv(SegStop, BI.LastUse); + } closeIntv(); } - rewrite(); - return dupli_; + finish(); } @@ -1025,31 +965,29 @@ bool SplitEditor::splitSingleBlocks(const SplitAnalysis::BlockPtrSet &Blocks) { // Sub Block Splitting //===----------------------------------------------------------------------===// -/// getBlockForInsideSplit - If curli is contained inside a single basic block, +/// getBlockForInsideSplit - If CurLI is contained inside a single basic block, /// and it wou pay to subdivide the interval inside that block, return it. /// Otherwise return NULL. The returned block can be passed to /// SplitEditor::splitInsideBlock. const MachineBasicBlock *SplitAnalysis::getBlockForInsideSplit() { // The interval must be exclusive to one block. - if (usingBlocks_.size() != 1) + if (UsingBlocks.size() != 1) return 0; // Don't to this for less than 4 instructions. We want to be sure that // splitting actually reduces the instruction count per interval. - if (usingInstrs_.size() < 4) + if (UsingInstrs.size() < 4) return 0; - return usingBlocks_.begin()->first; + return UsingBlocks.begin()->first; } -/// splitInsideBlock - Split curli into multiple intervals inside MBB. Return -/// true if curli has been completely replaced, false if curli is still -/// intact, and needs to be spilled or split further. -bool SplitEditor::splitInsideBlock(const MachineBasicBlock *MBB) { +/// splitInsideBlock - Split CurLI into multiple intervals inside MBB. +void SplitEditor::splitInsideBlock(const MachineBasicBlock *MBB) { SmallVector<SlotIndex, 32> Uses; - Uses.reserve(sa_.usingInstrs_.size()); - for (SplitAnalysis::InstrPtrSet::const_iterator I = sa_.usingInstrs_.begin(), - E = sa_.usingInstrs_.end(); I != E; ++I) + Uses.reserve(SA.UsingInstrs.size()); + for (SplitAnalysis::InstrPtrSet::const_iterator I = SA.UsingInstrs.begin(), + E = SA.UsingInstrs.end(); I != E; ++I) if ((*I)->getParent() == MBB) - Uses.push_back(lis_.getInstructionIndex(*I)); + Uses.push_back(LIS.getInstructionIndex(*I)); DEBUG(dbgs() << " splitInsideBlock BB#" << MBB->getNumber() << " for " << Uses.size() << " instructions.\n"); assert(Uses.size() >= 3 && "Need at least 3 instructions"); @@ -1077,21 +1015,16 @@ bool SplitEditor::splitInsideBlock(const MachineBasicBlock *MBB) { // First interval before the gap. Don't create single-instr intervals. if (bestPos > 1) { openIntv(); - enterIntvBefore(Uses.front()); - useIntv(Uses.front().getBaseIndex(), Uses[bestPos-1].getBoundaryIndex()); - leaveIntvAfter(Uses[bestPos-1]); + useIntv(enterIntvBefore(Uses.front()), leaveIntvAfter(Uses[bestPos-1])); closeIntv(); } // Second interval after the gap. if (bestPos < Uses.size()-1) { openIntv(); - enterIntvBefore(Uses[bestPos]); - useIntv(Uses[bestPos].getBaseIndex(), Uses.back().getBoundaryIndex()); - leaveIntvAfter(Uses.back()); + useIntv(enterIntvBefore(Uses[bestPos]), leaveIntvAfter(Uses.back())); closeIntv(); } - rewrite(); - return dupli_; + finish(); } |
