#include "llvm/CodeGen/MachineLoopInfo.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/RegAllocRegistry.h"
+#include "llvm/CodeGen/RegisterClassInfo.h"
#include "llvm/CodeGen/VirtRegMap.h"
#include "llvm/PassAnalysisSupport.h"
#include "llvm/Support/CommandLine.h"
clEnumValEnd),
cl::init(SplitEditor::SM_Partition));
+static cl::opt<unsigned>
+LastChanceRecoloringMaxDepth("lcr-max-depth", cl::Hidden,
+ cl::desc("Last chance recoloring max depth"),
+ cl::init(5));
+
+static cl::opt<unsigned> LastChanceRecoloringMaxInterference(
+ "lcr-max-interf", cl::Hidden,
+ cl::desc("Last chance recoloring maximum number of considered"
+ " interference at a time"),
+ cl::init(8));
+
static RegisterRegAlloc greedyRegAlloc("greedy", "greedy register allocator",
createGreedyRegisterAllocator);
class RAGreedy : public MachineFunctionPass,
public RegAllocBase,
private LiveRangeEdit::Delegate {
+ // Convenient shortcuts.
+ typedef std::priority_queue<std::pair<unsigned, unsigned> > PQueue;
+ typedef SmallPtrSet<LiveInterval *, 4> SmallLISet;
+ typedef SmallSet<unsigned, 16> SmallVirtRegSet;
// context
MachineFunction *MF;
+ // Shortcuts to some useful interface.
+ const TargetInstrInfo *TII;
+ const TargetRegisterInfo *TRI;
+ RegisterClassInfo RCI;
+
// analyses
SlotIndexes *Indexes;
MachineBlockFrequencyInfo *MBFI;
// state
OwningPtr<Spiller> SpillerInstance;
- std::priority_queue<std::pair<unsigned, unsigned> > Queue;
+ PQueue Queue;
unsigned NextCascade;
// Live ranges pass through a number of stages as we try to allocate them.
unsigned BrokenHints; ///< Total number of broken hints.
float MaxWeight; ///< Maximum spill weight evicted.
- EvictionCost(unsigned B = 0) : BrokenHints(B), MaxWeight(0) {}
+ EvictionCost(): BrokenHints(0), MaxWeight(0) {}
bool isMax() const { return BrokenHints == ~0u; }
+ void setMax() { BrokenHints = ~0u; }
+
+ void setBrokenHints(unsigned NHints) { BrokenHints = NHints; }
+
bool operator<(const EvictionCost &O) const {
if (BrokenHints != O.BrokenHints)
return BrokenHints < O.BrokenHints;
}
};
- /// Candidate info for for each PhysReg in AllocationOrder.
+ /// Candidate info for each PhysReg in AllocationOrder.
/// This vector never shrinks, but grows to the size of the largest register
/// class.
SmallVector<GlobalSplitCandidate, 32> GlobalCand;
- enum { NoCand = ~0u };
+ enum LLVM_ENUM_INT_TYPE(unsigned) { NoCand = ~0u };
/// Candidate map. Each edge bundle is assigned to a GlobalCand entry, or to
/// NoCand which indicates the stack interval.
static char ID;
private:
+ unsigned selectOrSplitImpl(LiveInterval &, SmallVectorImpl<unsigned> &,
+ SmallVirtRegSet &, unsigned = 0);
+
bool LRE_CanEraseVirtReg(unsigned);
void LRE_WillShrinkVirtReg(unsigned);
void LRE_DidCloneVirtReg(unsigned, unsigned);
+ void enqueue(PQueue &CurQueue, LiveInterval *LI);
+ LiveInterval *dequeue(PQueue &CurQueue);
BlockFrequency calcSpillCost();
bool addSplitConstraints(InterferenceCache::Cursor, BlockFrequency&);
bool canEvictInterference(LiveInterval&, unsigned, bool, EvictionCost&);
void evictInterference(LiveInterval&, unsigned,
SmallVectorImpl<unsigned>&);
+ bool mayRecolorAllInterferences(unsigned PhysReg, LiveInterval &VirtReg,
+ SmallLISet &RecoloringCandidates,
+ const SmallVirtRegSet &FixedRegisters);
unsigned tryAssign(LiveInterval&, AllocationOrder&,
SmallVectorImpl<unsigned>&);
SmallVectorImpl<unsigned>&);
unsigned trySplit(LiveInterval&, AllocationOrder&,
SmallVectorImpl<unsigned>&);
+ unsigned tryLastChanceRecoloring(LiveInterval &, AllocationOrder &,
+ SmallVectorImpl<unsigned> &,
+ SmallVirtRegSet &, unsigned);
+ bool tryRecoloringCandidates(PQueue &, SmallVectorImpl<unsigned> &,
+ SmallVirtRegSet &, unsigned);
};
} // end anonymous namespace
// Hysteresis to use when comparing floats.
// This helps stabilize decisions based on float comparisons.
-const float Hysteresis = 0.98f;
+const float Hysteresis = (2007 / 2048.0f); // 0.97998046875
FunctionPass* llvm::createGreedyRegisterAllocator() {
initializeSlotIndexesPass(*PassRegistry::getPassRegistry());
initializeRegisterCoalescerPass(*PassRegistry::getPassRegistry());
initializeMachineSchedulerPass(*PassRegistry::getPassRegistry());
- initializeCalculateSpillWeightsPass(*PassRegistry::getPassRegistry());
initializeLiveStacksPass(*PassRegistry::getPassRegistry());
initializeMachineDominatorTreePass(*PassRegistry::getPassRegistry());
initializeMachineLoopInfoPass(*PassRegistry::getPassRegistry());
AU.addPreserved<LiveDebugVariables>();
AU.addRequired<LiveStacks>();
AU.addPreserved<LiveStacks>();
- AU.addRequired<CalculateSpillWeights>();
AU.addRequired<MachineDominatorTree>();
AU.addPreserved<MachineDominatorTree>();
AU.addRequired<MachineLoopInfo>();
GlobalCand.clear();
}
-void RAGreedy::enqueue(LiveInterval *LI) {
+void RAGreedy::enqueue(LiveInterval *LI) { enqueue(Queue, LI); }
+
+void RAGreedy::enqueue(PQueue &CurQueue, LiveInterval *LI) {
// Prioritize live ranges by size, assigning larger ranges first.
// The queue holds (size, reg) pairs.
const unsigned Size = LI->getSize();
// Allocate original local ranges in linear instruction order. Since they
// are singly defined, this produces optimal coloring in the absence of
// global interference and other constraints.
- Prio = LI->beginIndex().getInstrDistance(Indexes->getLastIndex());
+ if (!TRI->reverseLocalAssignment())
+ Prio = LI->beginIndex().getInstrDistance(Indexes->getLastIndex());
+ else {
+ // Allocating bottom up may allow many short LRGs to be assigned first
+ // to one of the cheap registers. This could be much faster for very
+ // large blocks on targets with many physical registers.
+ Prio = Indexes->getZeroIndex().getInstrDistance(LI->beginIndex());
+ }
}
else {
// Allocate global and split ranges in long->short order. Long ranges that
}
// The virtual register number is a tie breaker for same-sized ranges.
// Give lower vreg numbers higher priority to assign them first.
- Queue.push(std::make_pair(Prio, ~Reg));
+ CurQueue.push(std::make_pair(Prio, ~Reg));
}
-LiveInterval *RAGreedy::dequeue() {
- if (Queue.empty())
+LiveInterval *RAGreedy::dequeue() { return dequeue(Queue); }
+
+LiveInterval *RAGreedy::dequeue(PQueue &CurQueue) {
+ if (CurQueue.empty())
return 0;
- LiveInterval *LI = &LIS->getInterval(~Queue.top().second);
- Queue.pop();
+ LiveInterval *LI = &LIS->getInterval(~CurQueue.top().second);
+ CurQueue.pop();
return LI;
}
if (unsigned Hint = MRI->getSimpleHint(VirtReg.reg))
if (Order.isHint(Hint)) {
DEBUG(dbgs() << "missed hint " << PrintReg(Hint, TRI) << '\n');
- EvictionCost MaxCost(1);
+ EvictionCost MaxCost;
+ MaxCost.setBrokenHints(1);
if (canEvictInterference(VirtReg, Hint, true, MaxCost)) {
evictInterference(VirtReg, Hint, NewVRegs);
return Hint;
if (CanSplit && IsHint && !BreaksHint)
return true;
- return A.weight > B.weight;
+ if (A.weight > B.weight) {
+ DEBUG(dbgs() << "should evict: " << B << " w= " << B.weight << '\n');
+ return true;
+ }
+ return false;
}
/// canEvictInterference - Return true if all interferences between VirtReg and
return false;
if (Urgent)
continue;
+ // Apply the eviction policy for non-urgent evictions.
+ if (!shouldEvict(VirtReg, IsHint, *Intf, BreaksHint))
+ return false;
// If !MaxCost.isMax(), then we're just looking for a cheap register.
// Evicting another local live range in this case could lead to suboptimal
// coloring.
!canReassign(*Intf, PhysReg)) {
return false;
}
- // Finally, apply the eviction policy for non-urgent evictions.
- if (!shouldEvict(VirtReg, IsHint, *Intf, BreaksHint))
- return false;
}
}
MaxCost = Cost;
NamedRegionTimer T("Evict", TimerGroupName, TimePassesIsEnabled);
// Keep track of the cheapest interference seen so far.
- EvictionCost BestCost(~0u);
+ EvictionCost BestCost;
+ BestCost.setMax();
unsigned BestPhys = 0;
unsigned OrderLimit = Order.getOrder().size();
}
Order.rewind();
- while (unsigned PhysReg = Order.nextWithDups(OrderLimit)) {
+ while (unsigned PhysReg = Order.next(OrderLimit)) {
if (TRI->getCostPerUse(PhysReg) >= CostPerUseLimit)
continue;
// The first use of a callee-saved register in a function has cost 1.
// No benefit from the compact region, our fallback will be per-block
// splitting. Make sure we find a solution that is cheaper than spilling.
BestCost = calcSpillCost();
- DEBUG(dbgs() << "Cost of isolating all blocks = " << BestCost << '\n');
+ DEBUG(dbgs() << "Cost of isolating all blocks = ";
+ MBFI->printBlockFreq(dbgs(), BestCost) << '\n');
}
Order.rewind();
DEBUG(dbgs() << PrintReg(PhysReg, TRI) << "\tno positive bundles\n");
continue;
}
- DEBUG(dbgs() << PrintReg(PhysReg, TRI) << "\tstatic = " << Cost);
+ DEBUG(dbgs() << PrintReg(PhysReg, TRI) << "\tstatic = ";
+ MBFI->printBlockFreq(dbgs(), Cost));
if (Cost >= BestCost) {
DEBUG({
if (BestCand == NoCand)
Cost += calcGlobalSplitCost(Cand);
DEBUG({
- dbgs() << ", total = " << Cost << " with bundles";
+ dbgs() << ", total = "; MBFI->printBlockFreq(dbgs(), Cost)
+ << " with bundles";
for (int i = Cand.LiveBundles.find_first(); i>=0;
i = Cand.LiveBundles.find_next(i))
dbgs() << " EB#" << i;
// Per-Instruction Splitting
//===----------------------------------------------------------------------===//
+/// Get the number of allocatable registers that match the constraints of \p Reg
+/// on \p MI and that are also in \p SuperRC.
+static unsigned getNumAllocatableRegsForConstraints(
+ const MachineInstr *MI, unsigned Reg, const TargetRegisterClass *SuperRC,
+ const TargetInstrInfo *TII, const TargetRegisterInfo *TRI,
+ const RegisterClassInfo &RCI) {
+ assert(SuperRC && "Invalid register class");
+
+ const TargetRegisterClass *ConstrainedRC =
+ MI->getRegClassConstraintEffectForVReg(Reg, SuperRC, TII, TRI,
+ /* ExploreBundle */ true);
+ if (!ConstrainedRC)
+ return 0;
+ return RCI.getNumAllocatableRegs(ConstrainedRC);
+}
+
/// tryInstructionSplit - Split a live range around individual instructions.
/// This is normally not worthwhile since the spiller is doing essentially the
/// same thing. However, when the live range is in a constrained register
unsigned
RAGreedy::tryInstructionSplit(LiveInterval &VirtReg, AllocationOrder &Order,
SmallVectorImpl<unsigned> &NewVRegs) {
+ const TargetRegisterClass *CurRC = MRI->getRegClass(VirtReg.reg);
// There is no point to this if there are no larger sub-classes.
- if (!RegClassInfo.isProperSubClass(MRI->getRegClass(VirtReg.reg)))
+ if (!RegClassInfo.isProperSubClass(CurRC))
return 0;
// Always enable split spill mode, since we're effectively spilling to a
DEBUG(dbgs() << "Split around " << Uses.size() << " individual instrs.\n");
- // Split around every non-copy instruction.
+ const TargetRegisterClass *SuperRC = TRI->getLargestLegalSuperClass(CurRC);
+ unsigned SuperRCNumAllocatableRegs = RCI.getNumAllocatableRegs(SuperRC);
+ // Split around every non-copy instruction if this split will relax
+ // the constraints on the virtual register.
+ // Otherwise, splitting just inserts uncoalescable copies that do not help
+ // the allocation.
for (unsigned i = 0; i != Uses.size(); ++i) {
if (const MachineInstr *MI = Indexes->getInstructionFromIndex(Uses[i]))
- if (MI->isFullCopy()) {
+ if (MI->isFullCopy() ||
+ SuperRCNumAllocatableRegs ==
+ getNumAllocatableRegsForConstraints(MI, VirtReg.reg, SuperRC, TII,
+ TRI, RCI)) {
DEBUG(dbgs() << " skip:\t" << Uses[i] << '\t' << *MI);
continue;
}
// Add fixed interference.
for (MCRegUnitIterator Units(PhysReg, TRI); Units.isValid(); ++Units) {
- const LiveInterval &LI = LIS->getRegUnit(*Units);
- LiveInterval::const_iterator I = LI.find(StartIdx);
- LiveInterval::const_iterator E = LI.end();
+ const LiveRange &LR = LIS->getRegUnit(*Units);
+ LiveRange::const_iterator I = LR.find(StartIdx);
+ LiveRange::const_iterator E = LR.end();
// Same loop as above. Mark any overlapped gaps as HUGE_VALF.
for (unsigned Gap = 0; I != E && I->start < StopIdx; ++I) {
break;
for (; Gap != NumGaps; ++Gap) {
- GapWeight[Gap] = HUGE_VALF;
+ GapWeight[Gap] = llvm::huge_valf;
if (Uses[Gap+1].getBaseIndex() >= I->end)
break;
}
const float blockFreq =
SpillPlacer->getBlockFrequency(BI.MBB->getNumber()).getFrequency() *
- (1.0f / BlockFrequency::getEntryFrequency());
+ (1.0f / MBFI->getEntryFreq());
SmallVector<float, 8> GapWeight;
Order.rewind();
// Remove any gaps with regmask clobbers.
if (Matrix->checkRegMaskInterference(VirtReg, PhysReg))
for (unsigned i = 0, e = RegMaskGaps.size(); i != e; ++i)
- GapWeight[RegMaskGaps[i]] = HUGE_VALF;
+ GapWeight[RegMaskGaps[i]] = llvm::huge_valf;
// Try to find the best sequence of gaps to close.
// The new spill weight must be larger than any gap interference.
// Legally, without causing looping?
bool Legal = !ProgressRequired || NewGaps < NumGaps;
- if (Legal && MaxGap < HUGE_VALF) {
+ if (Legal && MaxGap < llvm::huge_valf) {
// Estimate the new spill weight. Each instruction reads or writes the
// register. Conservatively assume there are no read-modify-write
// instructions.
return tryBlockSplit(VirtReg, Order, NewVRegs);
}
+//===----------------------------------------------------------------------===//
+// Last Chance Recoloring
+//===----------------------------------------------------------------------===//
+
+/// mayRecolorAllInterferences - Check if the virtual registers that
+/// interfere with \p VirtReg on \p PhysReg (or one of its aliases) may be
+/// recolored to free \p PhysReg.
+/// When true is returned, \p RecoloringCandidates has been augmented with all
+/// the live intervals that need to be recolored in order to free \p PhysReg
+/// for \p VirtReg.
+/// \p FixedRegisters contains all the virtual registers that cannot be
+/// recolored.
+bool
+RAGreedy::mayRecolorAllInterferences(unsigned PhysReg, LiveInterval &VirtReg,
+ SmallLISet &RecoloringCandidates,
+ const SmallVirtRegSet &FixedRegisters) {
+ const TargetRegisterClass *CurRC = MRI->getRegClass(VirtReg.reg);
+
+ for (MCRegUnitIterator Units(PhysReg, TRI); Units.isValid(); ++Units) {
+ LiveIntervalUnion::Query &Q = Matrix->query(VirtReg, *Units);
+ // If there is LastChanceRecoloringMaxInterference or more interferences,
+ // chances are one would not be recolorable.
+ if (Q.collectInterferingVRegs(LastChanceRecoloringMaxInterference) >=
+ LastChanceRecoloringMaxInterference) {
+ DEBUG(dbgs() << "Early abort: too many interferences.\n");
+ return false;
+ }
+ for (unsigned i = Q.interferingVRegs().size(); i; --i) {
+ LiveInterval *Intf = Q.interferingVRegs()[i - 1];
+ // If Intf is done and sit on the same register class as VirtReg,
+ // it would not be recolorable as it is in the same state as VirtReg.
+ if ((getStage(*Intf) == RS_Done &&
+ MRI->getRegClass(Intf->reg) == CurRC) ||
+ FixedRegisters.count(Intf->reg)) {
+ DEBUG(dbgs() << "Early abort: the inteference is not recolorable.\n");
+ return false;
+ }
+ RecoloringCandidates.insert(Intf);
+ }
+ }
+ return true;
+}
+
+/// tryLastChanceRecoloring - Try to assign a color to \p VirtReg by recoloring
+/// its interferences.
+/// Last chance recoloring chooses a color for \p VirtReg and recolors every
+/// virtual register that was using it. The recoloring process may recursively
+/// use the last chance recoloring. Therefore, when a virtual register has been
+/// assigned a color by this mechanism, it is marked as Fixed, i.e., it cannot
+/// be last-chance-recolored again during this recoloring "session".
+/// E.g.,
+/// Let
+/// vA can use {R1, R2 }
+/// vB can use { R2, R3}
+/// vC can use {R1 }
+/// Where vA, vB, and vC cannot be split anymore (they are reloads for
+/// instance) and they all interfere.
+///
+/// vA is assigned R1
+/// vB is assigned R2
+/// vC tries to evict vA but vA is already done.
+/// Regular register allocation fails.
+///
+/// Last chance recoloring kicks in:
+/// vC does as if vA was evicted => vC uses R1.
+/// vC is marked as fixed.
+/// vA needs to find a color.
+/// None are available.
+/// vA cannot evict vC: vC is a fixed virtual register now.
+/// vA does as if vB was evicted => vA uses R2.
+/// vB needs to find a color.
+/// R3 is available.
+/// Recoloring => vC = R1, vA = R2, vB = R3
+///
+/// \p Order defines the prefered allocation order for \p VirtReg.
+/// \p NewRegs will contain any new virtual register that have been created
+/// (split, spill) during the process and that must be assigned.
+/// \p FixedRegisters contains all the virtual registers that cannot be
+/// recolored.
+/// \p Depth gives the current depth of the last chance recoloring.
+/// \return a physical register that can be used for VirtReg or ~0u if none
+/// exists.
+unsigned RAGreedy::tryLastChanceRecoloring(LiveInterval &VirtReg,
+ AllocationOrder &Order,
+ SmallVectorImpl<unsigned> &NewVRegs,
+ SmallVirtRegSet &FixedRegisters,
+ unsigned Depth) {
+ DEBUG(dbgs() << "Try last chance recoloring for " << VirtReg << '\n');
+ // Ranges must be Done.
+ assert(getStage(VirtReg) >= RS_Done &&
+ "Last chance recoloring should really be last chance");
+ // Set the max depth to LastChanceRecoloringMaxDepth.
+ // We may want to reconsider that if we end up with a too large search space
+ // for target with hundreds of registers.
+ // Indeed, in that case we may want to cut the search space earlier.
+ if (Depth >= LastChanceRecoloringMaxDepth) {
+ DEBUG(dbgs() << "Abort because max depth has been reached.\n");
+ return ~0u;
+ }
+
+ // Set of Live intervals that will need to be recolored.
+ SmallLISet RecoloringCandidates;
+ // Record the original mapping virtual register to physical register in case
+ // the recoloring fails.
+ DenseMap<unsigned, unsigned> VirtRegToPhysReg;
+ // Mark VirtReg as fixed, i.e., it will not be recolored pass this point in
+ // this recoloring "session".
+ FixedRegisters.insert(VirtReg.reg);
+
+ Order.rewind();
+ while (unsigned PhysReg = Order.next()) {
+ DEBUG(dbgs() << "Try to assign: " << VirtReg << " to "
+ << PrintReg(PhysReg, TRI) << '\n');
+ RecoloringCandidates.clear();
+ VirtRegToPhysReg.clear();
+
+ // It is only possible to recolor virtual register interference.
+ if (Matrix->checkInterference(VirtReg, PhysReg) >
+ LiveRegMatrix::IK_VirtReg) {
+ DEBUG(dbgs() << "Some inteferences are not with virtual registers.\n");
+
+ continue;
+ }
+
+ // Early give up on this PhysReg if it is obvious we cannot recolor all
+ // the interferences.
+ if (!mayRecolorAllInterferences(PhysReg, VirtReg, RecoloringCandidates,
+ FixedRegisters)) {
+ DEBUG(dbgs() << "Some inteferences cannot be recolored.\n");
+ continue;
+ }
+
+ // RecoloringCandidates contains all the virtual registers that interfer
+ // with VirtReg on PhysReg (or one of its aliases).
+ // Enqueue them for recoloring and perform the actual recoloring.
+ PQueue RecoloringQueue;
+ for (SmallLISet::iterator It = RecoloringCandidates.begin(),
+ EndIt = RecoloringCandidates.end();
+ It != EndIt; ++It) {
+ unsigned ItVirtReg = (*It)->reg;
+ enqueue(RecoloringQueue, *It);
+ assert(VRM->hasPhys(ItVirtReg) &&
+ "Interferences are supposed to be with allocated vairables");
+
+ // Record the current allocation.
+ VirtRegToPhysReg[ItVirtReg] = VRM->getPhys(ItVirtReg);
+ // unset the related struct.
+ Matrix->unassign(**It);
+ }
+
+ // Do as if VirtReg was assigned to PhysReg so that the underlying
+ // recoloring has the right information about the interferes and
+ // available colors.
+ Matrix->assign(VirtReg, PhysReg);
+
+ // Save the current recoloring state.
+ // If we cannot recolor all the interferences, we will have to start again
+ // at this point for the next physical register.
+ SmallVirtRegSet SaveFixedRegisters(FixedRegisters);
+ if (tryRecoloringCandidates(RecoloringQueue, NewVRegs, FixedRegisters,
+ Depth)) {
+ // Do not mess up with the global assignment process.
+ // I.e., VirtReg must be unassigned.
+ Matrix->unassign(VirtReg);
+ return PhysReg;
+ }
+
+ DEBUG(dbgs() << "Fail to assign: " << VirtReg << " to "
+ << PrintReg(PhysReg, TRI) << '\n');
+
+ // The recoloring attempt failed, undo the changes.
+ FixedRegisters = SaveFixedRegisters;
+ Matrix->unassign(VirtReg);
+
+ for (SmallLISet::iterator It = RecoloringCandidates.begin(),
+ EndIt = RecoloringCandidates.end();
+ It != EndIt; ++It) {
+ unsigned ItVirtReg = (*It)->reg;
+ if (VRM->hasPhys(ItVirtReg))
+ Matrix->unassign(**It);
+ Matrix->assign(**It, VirtRegToPhysReg[ItVirtReg]);
+ }
+ }
+
+ // Last chance recoloring did not worked either, give up.
+ return ~0u;
+}
+
+/// tryRecoloringCandidates - Try to assign a new color to every register
+/// in \RecoloringQueue.
+/// \p NewRegs will contain any new virtual register created during the
+/// recoloring process.
+/// \p FixedRegisters[in/out] contains all the registers that have been
+/// recolored.
+/// \return true if all virtual registers in RecoloringQueue were successfully
+/// recolored, false otherwise.
+bool RAGreedy::tryRecoloringCandidates(PQueue &RecoloringQueue,
+ SmallVectorImpl<unsigned> &NewVRegs,
+ SmallVirtRegSet &FixedRegisters,
+ unsigned Depth) {
+ while (!RecoloringQueue.empty()) {
+ LiveInterval *LI = dequeue(RecoloringQueue);
+ DEBUG(dbgs() << "Try to recolor: " << *LI << '\n');
+ unsigned PhysReg;
+ PhysReg = selectOrSplitImpl(*LI, NewVRegs, FixedRegisters, Depth + 1);
+ if (PhysReg == ~0u || !PhysReg)
+ return false;
+ DEBUG(dbgs() << "Recoloring of " << *LI
+ << " succeeded with: " << PrintReg(PhysReg, TRI) << '\n');
+ Matrix->assign(*LI, PhysReg);
+ FixedRegisters.insert(LI->reg);
+ }
+ return true;
+}
//===----------------------------------------------------------------------===//
// Main Entry Point
unsigned RAGreedy::selectOrSplit(LiveInterval &VirtReg,
SmallVectorImpl<unsigned> &NewVRegs) {
+ SmallVirtRegSet FixedRegisters;
+ return selectOrSplitImpl(VirtReg, NewVRegs, FixedRegisters);
+}
+
+unsigned RAGreedy::selectOrSplitImpl(LiveInterval &VirtReg,
+ SmallVectorImpl<unsigned> &NewVRegs,
+ SmallVirtRegSet &FixedRegisters,
+ unsigned Depth) {
// First try assigning a free register.
AllocationOrder Order(VirtReg.reg, *VRM, RegClassInfo);
if (unsigned PhysReg = tryAssign(VirtReg, Order, NewVRegs))
// If we couldn't allocate a register from spilling, there is probably some
// invalid inline assembly. The base class wil report it.
if (Stage >= RS_Done || !VirtReg.isSpillable())
- return ~0u;
+ return tryLastChanceRecoloring(VirtReg, Order, NewVRegs, FixedRegisters,
+ Depth);
// Try splitting VirtReg or interferences.
unsigned PhysReg = trySplit(VirtReg, Order, NewVRegs);
<< "********** Function: " << mf.getName() << '\n');
MF = &mf;
+ TRI = MF->getTarget().getRegisterInfo();
+ TII = MF->getTarget().getInstrInfo();
+ RCI.runOnMachineFunction(mf);
if (VerifyEnabled)
MF->verify(this, "Before greedy register allocator");
SpillPlacer = &getAnalysis<SpillPlacement>();
DebugVars = &getAnalysis<LiveDebugVariables>();
+ calculateSpillWeightsAndHints(*LIS, mf, *Loops, *MBFI);
+
DEBUG(LIS->dump());
SA.reset(new SplitAnalysis(*VRM, *LIS, *Loops));
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