6502/llvm-6502
1
0
Fork 0
mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2024-07-26 06:29:20 +00:00
Code Issues Projects Releases Wiki Activity
06c0f25499
llvm-6502/lib/CodeGen/RegAllocGreedy.cpp
Jakob Stoklund Olesen 06c0f25499 Add SplitKit::isOriginalEndpoint and use it to force live range splitting to terminate. 
An original endpoint is an instruction that killed or defined the original live
range before any live ranges were split.

When splitting global live ranges, avoid creating local live ranges without any
original endpoints. We may still create global live ranges without original
endpoints, but such a range won't be split again, and live range splitting still
terminates.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@126151 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-21 23:09:46 +00:00

1295 lines
46 KiB
C++
Raw Blame History

//===-- RegAllocGreedy.cpp - greedy register allocator --------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file defines the RAGreedy function pass for register allocation in
// optimized builds.
//
//===----------------------------------------------------------------------===//
#define DEBUG_TYPE "regalloc"
#include "AllocationOrder.h"
#include "LiveIntervalUnion.h"
#include "LiveRangeEdit.h"
#include "RegAllocBase.h"
#include "Spiller.h"
#include "SpillPlacement.h"
#include "SplitKit.h"
#include "VirtRegMap.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/Analysis/AliasAnalysis.h"
#include "llvm/Function.h"
#include "llvm/PassAnalysisSupport.h"
#include "llvm/CodeGen/CalcSpillWeights.h"
#include "llvm/CodeGen/EdgeBundles.h"
#include "llvm/CodeGen/LiveIntervalAnalysis.h"
#include "llvm/CodeGen/LiveStackAnalysis.h"
#include "llvm/CodeGen/MachineDominators.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/CodeGen/MachineLoopInfo.h"
#include "llvm/CodeGen/MachineLoopRanges.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/Passes.h"
#include "llvm/CodeGen/RegAllocRegistry.h"
#include "llvm/CodeGen/RegisterCoalescer.h"
#include "llvm/Target/TargetOptions.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Support/Timer.h"
using namespace llvm;
STATISTIC(NumGlobalSplits, "Number of split global live ranges");
STATISTIC(NumLocalSplits, "Number of split local live ranges");
STATISTIC(NumReassigned, "Number of interferences reassigned");
STATISTIC(NumEvicted, "Number of interferences evicted");
static RegisterRegAlloc greedyRegAlloc("greedy", "greedy register allocator",
createGreedyRegisterAllocator);
namespace {
class RAGreedy : public MachineFunctionPass, public RegAllocBase {
// context
MachineFunction *MF;
BitVector ReservedRegs;
// analyses
SlotIndexes *Indexes;
LiveStacks *LS;
MachineDominatorTree *DomTree;
MachineLoopInfo *Loops;
MachineLoopRanges *LoopRanges;
EdgeBundles *Bundles;
SpillPlacement *SpillPlacer;
// state
std::auto_ptr<Spiller> SpillerInstance;
std::auto_ptr<SplitAnalysis> SA;
// splitting state.
/// All basic blocks where the current register is live.
SmallVector<SpillPlacement::BlockConstraint, 8> SpillConstraints;
/// For every instruction in SA->UseSlots, store the previous non-copy
/// instruction.
SmallVector<SlotIndex, 8> PrevSlot;
public:
RAGreedy();
/// Return the pass name.
virtual const char* getPassName() const {
return "Greedy Register Allocator";
}
/// RAGreedy analysis usage.
virtual void getAnalysisUsage(AnalysisUsage &AU) const;
virtual void releaseMemory();
virtual Spiller &spiller() { return *SpillerInstance; }
virtual float getPriority(LiveInterval *LI);
virtual unsigned selectOrSplit(LiveInterval&,
SmallVectorImpl<LiveInterval*>&);
/// Perform register allocation.
virtual bool runOnMachineFunction(MachineFunction &mf);
static char ID;
private:
bool checkUncachedInterference(LiveInterval&, unsigned);
LiveInterval *getSingleInterference(LiveInterval&, unsigned);
bool reassignVReg(LiveInterval &InterferingVReg, unsigned OldPhysReg);
float calcInterferenceWeight(LiveInterval&, unsigned);
float calcInterferenceInfo(LiveInterval&, unsigned);
float calcGlobalSplitCost(const BitVector&);
void splitAroundRegion(LiveInterval&, unsigned, const BitVector&,
SmallVectorImpl<LiveInterval*>&);
void calcGapWeights(unsigned, SmallVectorImpl<float>&);
SlotIndex getPrevMappedIndex(const MachineInstr*);
void calcPrevSlots();
unsigned nextSplitPoint(unsigned);
unsigned tryReassignOrEvict(LiveInterval&, AllocationOrder&,
SmallVectorImpl<LiveInterval*>&);
unsigned tryRegionSplit(LiveInterval&, AllocationOrder&,
SmallVectorImpl<LiveInterval*>&);
unsigned tryLocalSplit(LiveInterval&, AllocationOrder&,
SmallVectorImpl<LiveInterval*>&);
unsigned trySplit(LiveInterval&, AllocationOrder&,
SmallVectorImpl<LiveInterval*>&);
unsigned trySpillInterferences(LiveInterval&, AllocationOrder&,
SmallVectorImpl<LiveInterval*>&);
};
} // end anonymous namespace
char RAGreedy::ID = 0;
FunctionPass* llvm::createGreedyRegisterAllocator() {
return new RAGreedy();
}
RAGreedy::RAGreedy(): MachineFunctionPass(ID) {
initializeSlotIndexesPass(*PassRegistry::getPassRegistry());
initializeLiveIntervalsPass(*PassRegistry::getPassRegistry());
initializeSlotIndexesPass(*PassRegistry::getPassRegistry());
initializeStrongPHIEliminationPass(*PassRegistry::getPassRegistry());
initializeRegisterCoalescerAnalysisGroup(*PassRegistry::getPassRegistry());
initializeCalculateSpillWeightsPass(*PassRegistry::getPassRegistry());
initializeLiveStacksPass(*PassRegistry::getPassRegistry());
initializeMachineDominatorTreePass(*PassRegistry::getPassRegistry());
initializeMachineLoopInfoPass(*PassRegistry::getPassRegistry());
initializeMachineLoopRangesPass(*PassRegistry::getPassRegistry());
initializeVirtRegMapPass(*PassRegistry::getPassRegistry());
initializeEdgeBundlesPass(*PassRegistry::getPassRegistry());
initializeSpillPlacementPass(*PassRegistry::getPassRegistry());
}
void RAGreedy::getAnalysisUsage(AnalysisUsage &AU) const {
AU.setPreservesCFG();
AU.addRequired<AliasAnalysis>();
AU.addPreserved<AliasAnalysis>();
AU.addRequired<LiveIntervals>();
AU.addRequired<SlotIndexes>();
AU.addPreserved<SlotIndexes>();
if (StrongPHIElim)
AU.addRequiredID(StrongPHIEliminationID);
AU.addRequiredTransitive<RegisterCoalescer>();
AU.addRequired<CalculateSpillWeights>();
AU.addRequired<LiveStacks>();
AU.addPreserved<LiveStacks>();
AU.addRequired<MachineDominatorTree>();
AU.addPreserved<MachineDominatorTree>();
AU.addRequired<MachineLoopInfo>();
AU.addPreserved<MachineLoopInfo>();
AU.addRequired<MachineLoopRanges>();
AU.addPreserved<MachineLoopRanges>();
AU.addRequired<VirtRegMap>();
AU.addPreserved<VirtRegMap>();
AU.addRequired<EdgeBundles>();
AU.addRequired<SpillPlacement>();
MachineFunctionPass::getAnalysisUsage(AU);
}
void RAGreedy::releaseMemory() {
SpillerInstance.reset(0);
RegAllocBase::releaseMemory();
}
float RAGreedy::getPriority(LiveInterval *LI) {
float Priority = LI->weight;
// Prioritize hinted registers so they are allocated first.
std::pair<unsigned, unsigned> Hint;
if (Hint.first || Hint.second) {
// The hint can be target specific, a virtual register, or a physreg.
Priority *= 2;
// Prefer physreg hints above anything else.
if (Hint.first == 0 && TargetRegisterInfo::isPhysicalRegister(Hint.second))
Priority *= 2;
}
return Priority;
}
//===----------------------------------------------------------------------===//
// Register Reassignment
//===----------------------------------------------------------------------===//
// Check interference without using the cache.
bool RAGreedy::checkUncachedInterference(LiveInterval &VirtReg,
unsigned PhysReg) {
for (const unsigned *AliasI = TRI->getOverlaps(PhysReg); *AliasI; ++AliasI) {
LiveIntervalUnion::Query subQ(&VirtReg, &PhysReg2LiveUnion[*AliasI]);
if (subQ.checkInterference())
return true;
}
return false;
}
/// getSingleInterference - Return the single interfering virtual register
/// assigned to PhysReg. Return 0 if more than one virtual register is
/// interfering.
LiveInterval *RAGreedy::getSingleInterference(LiveInterval &VirtReg,
unsigned PhysReg) {
// Check physreg and aliases.
LiveInterval *Interference = 0;
for (const unsigned *AliasI = TRI->getOverlaps(PhysReg); *AliasI; ++AliasI) {
LiveIntervalUnion::Query &Q = query(VirtReg, *AliasI);
if (Q.checkInterference()) {
if (Interference)
return 0;
Q.collectInterferingVRegs(1);
if (!Q.seenAllInterferences())
return 0;
Interference = Q.interferingVRegs().front();
}
}
return Interference;
}
// Attempt to reassign this virtual register to a different physical register.
//
// FIXME: we are not yet caching these "second-level" interferences discovered
// in the sub-queries. These interferences can change with each call to
// selectOrSplit. However, we could implement a "may-interfere" cache that
// could be conservatively dirtied when we reassign or split.
//
// FIXME: This may result in a lot of alias queries. We could summarize alias
// live intervals in their parent register's live union, but it's messy.
bool RAGreedy::reassignVReg(LiveInterval &InterferingVReg,
unsigned WantedPhysReg) {
assert(TargetRegisterInfo::isVirtualRegister(InterferingVReg.reg) &&
"Can only reassign virtual registers");
assert(TRI->regsOverlap(WantedPhysReg, VRM->getPhys(InterferingVReg.reg)) &&
"inconsistent phys reg assigment");
AllocationOrder Order(InterferingVReg.reg, *VRM, ReservedRegs);
while (unsigned PhysReg = Order.next()) {
// Don't reassign to a WantedPhysReg alias.
if (TRI->regsOverlap(PhysReg, WantedPhysReg))
continue;
if (checkUncachedInterference(InterferingVReg, PhysReg))
continue;
// Reassign the interfering virtual reg to this physical reg.
unsigned OldAssign = VRM->getPhys(InterferingVReg.reg);
DEBUG(dbgs() << "reassigning: " << InterferingVReg << " from " <<
TRI->getName(OldAssign) << " to " << TRI->getName(PhysReg) << '\n');
unassign(InterferingVReg, OldAssign);
assign(InterferingVReg, PhysReg);
++NumReassigned;
return true;
}
return false;
}
/// tryReassignOrEvict - Try to reassign a single interferences to a different
/// physreg, or evict a single interference with a lower spill weight.
/// @param VirtReg Currently unassigned virtual register.
/// @param Order Physregs to try.
/// @return Physreg to assign VirtReg, or 0.
unsigned RAGreedy::tryReassignOrEvict(LiveInterval &VirtReg,
AllocationOrder &Order,
SmallVectorImpl<LiveInterval*> &NewVRegs){
NamedRegionTimer T("Reassign", TimerGroupName, TimePassesIsEnabled);
// Keep track of the lightest single interference seen so far.
float BestWeight = VirtReg.weight;
LiveInterval *BestVirt = 0;
unsigned BestPhys = 0;
Order.rewind();
while (unsigned PhysReg = Order.next()) {
LiveInterval *InterferingVReg = getSingleInterference(VirtReg, PhysReg);
if (!InterferingVReg)
continue;
if (TargetRegisterInfo::isPhysicalRegister(InterferingVReg->reg))
continue;
if (reassignVReg(*InterferingVReg, PhysReg))
return PhysReg;
// Cannot reassign, is this an eviction candidate?
if (InterferingVReg->weight < BestWeight) {
BestVirt = InterferingVReg;
BestPhys = PhysReg;
BestWeight = InterferingVReg->weight;
}
}
// Nothing reassigned, can we evict a lighter single interference?
if (BestVirt) {
DEBUG(dbgs() << "evicting lighter " << *BestVirt << '\n');
unassign(*BestVirt, VRM->getPhys(BestVirt->reg));
++NumEvicted;
NewVRegs.push_back(BestVirt);
return BestPhys;
}
return 0;
}
//===----------------------------------------------------------------------===//
// Region Splitting
//===----------------------------------------------------------------------===//
/// calcInterferenceInfo - Compute per-block outgoing and ingoing constraints
/// when considering interference from PhysReg. Also compute an optimistic local
/// cost of this interference pattern.
///
/// The final cost of a split is the local cost + global cost of preferences
/// broken by SpillPlacement.
///
float RAGreedy::calcInterferenceInfo(LiveInterval &VirtReg, unsigned PhysReg) {
// Reset interference dependent info.
SpillConstraints.resize(SA->LiveBlocks.size());
for (unsigned i = 0, e = SA->LiveBlocks.size(); i != e; ++i) {
SplitAnalysis::BlockInfo &BI = SA->LiveBlocks[i];
SpillPlacement::BlockConstraint &BC = SpillConstraints[i];
BC.Number = BI.MBB->getNumber();
BC.Entry = (BI.Uses && BI.LiveIn) ?
SpillPlacement::PrefReg : SpillPlacement::DontCare;
BC.Exit = (BI.Uses && BI.LiveOut) ?
SpillPlacement::PrefReg : SpillPlacement::DontCare;
BI.OverlapEntry = BI.OverlapExit = false;
}
// Add interference info from each PhysReg alias.
for (const unsigned *AI = TRI->getOverlaps(PhysReg); *AI; ++AI) {
if (!query(VirtReg, *AI).checkInterference())
continue;
LiveIntervalUnion::SegmentIter IntI =
PhysReg2LiveUnion[*AI].find(VirtReg.beginIndex());
if (!IntI.valid())
continue;
// Determine which blocks have interference live in or after the last split
// point.
for (unsigned i = 0, e = SA->LiveBlocks.size(); i != e; ++i) {
SplitAnalysis::BlockInfo &BI = SA->LiveBlocks[i];
SpillPlacement::BlockConstraint &BC = SpillConstraints[i];
SlotIndex Start, Stop;
tie(Start, Stop) = Indexes->getMBBRange(BI.MBB);
// Skip interference-free blocks.
if (IntI.start() >= Stop)
continue;
// Is the interference live-in?
if (BI.LiveIn) {
IntI.advanceTo(Start);
if (!IntI.valid())
break;
if (IntI.start() <= Start)
BC.Entry = SpillPlacement::MustSpill;
}
// Is the interference overlapping the last split point?
if (BI.LiveOut) {
if (IntI.stop() < BI.LastSplitPoint)
IntI.advanceTo(BI.LastSplitPoint.getPrevSlot());
if (!IntI.valid())
break;
if (IntI.start() < Stop)
BC.Exit = SpillPlacement::MustSpill;
}
}
// Rewind iterator and check other interferences.
IntI.find(VirtReg.beginIndex());
for (unsigned i = 0, e = SA->LiveBlocks.size(); i != e; ++i) {
SplitAnalysis::BlockInfo &BI = SA->LiveBlocks[i];
SpillPlacement::BlockConstraint &BC = SpillConstraints[i];
SlotIndex Start, Stop;
tie(Start, Stop) = Indexes->getMBBRange(BI.MBB);
// Skip interference-free blocks.
if (IntI.start() >= Stop)
continue;
// Handle transparent blocks with interference separately.
// Transparent blocks never incur any fixed cost.
if (BI.LiveThrough && !BI.Uses) {
IntI.advanceTo(Start);
if (!IntI.valid())
break;
if (IntI.start() >= Stop)
continue;
if (BC.Entry != SpillPlacement::MustSpill)
BC.Entry = SpillPlacement::PrefSpill;
if (BC.Exit != SpillPlacement::MustSpill)
BC.Exit = SpillPlacement::PrefSpill;
continue;
}
// Now we only have blocks with uses left.
// Check if the interference overlaps the uses.
assert(BI.Uses && "Non-transparent block without any uses");
// Check interference on entry.
if (BI.LiveIn && BC.Entry != SpillPlacement::MustSpill) {
IntI.advanceTo(Start);
if (!IntI.valid())
break;
// Not live in, but before the first use.
if (IntI.start() < BI.FirstUse) {
BC.Entry = SpillPlacement::PrefSpill;
// If the block contains a kill from an earlier split, never split
// again in the same block.
if (!BI.LiveThrough && !SA->isOriginalEndpoint(BI.Kill))
BC.Entry = SpillPlacement::MustSpill;
}
}
// Does interference overlap the uses in the entry segment
// [FirstUse;Kill)?
if (BI.LiveIn && !BI.OverlapEntry) {
IntI.advanceTo(BI.FirstUse);
if (!IntI.valid())
break;
// A live-through interval has no kill.
// Check [FirstUse;LastUse) instead.
if (IntI.start() < (BI.LiveThrough ? BI.LastUse : BI.Kill))
BI.OverlapEntry = true;
}
// Does interference overlap the uses in the exit segment [Def;LastUse)?
if (BI.LiveOut && !BI.LiveThrough && !BI.OverlapExit) {
IntI.advanceTo(BI.Def);
if (!IntI.valid())
break;
if (IntI.start() < BI.LastUse)
BI.OverlapExit = true;
}
// Check interference on exit.
if (BI.LiveOut && BC.Exit != SpillPlacement::MustSpill) {
// Check interference between LastUse and Stop.
if (BC.Exit != SpillPlacement::PrefSpill) {
IntI.advanceTo(BI.LastUse);
if (!IntI.valid())
break;
if (IntI.start() < Stop) {
BC.Exit = SpillPlacement::PrefSpill;
// Avoid splitting twice in the same block.
if (!BI.LiveThrough && !SA->isOriginalEndpoint(BI.Def))
BC.Exit = SpillPlacement::MustSpill;
}
}
}
}
}
// Accumulate a local cost of this interference pattern.
float LocalCost = 0;
for (unsigned i = 0, e = SA->LiveBlocks.size(); i != e; ++i) {
SplitAnalysis::BlockInfo &BI = SA->LiveBlocks[i];
if (!BI.Uses)
continue;
SpillPlacement::BlockConstraint &BC = SpillConstraints[i];
unsigned Inserts = 0;
// Do we need spill code for the entry segment?
if (BI.LiveIn)
Inserts += BI.OverlapEntry || BC.Entry != SpillPlacement::PrefReg;
// For the exit segment?
if (BI.LiveOut)
Inserts += BI.OverlapExit || BC.Exit != SpillPlacement::PrefReg;
// The local cost of spill code in this block is the block frequency times
// the number of spill instructions inserted.
if (Inserts)
LocalCost += Inserts * SpillPlacer->getBlockFrequency(BI.MBB);
}
DEBUG(dbgs() << "Local cost of " << PrintReg(PhysReg, TRI) << " = "
<< LocalCost << '\n');
return LocalCost;
}
/// calcGlobalSplitCost - Return the global split cost of following the split
/// pattern in LiveBundles. This cost should be added to the local cost of the
/// interference pattern in SpillConstraints.
///
float RAGreedy::calcGlobalSplitCost(const BitVector &LiveBundles) {
float GlobalCost = 0;
for (unsigned i = 0, e = SpillConstraints.size(); i != e; ++i) {
SpillPlacement::BlockConstraint &BC = SpillConstraints[i];
unsigned Inserts = 0;
// Broken entry preference?
Inserts += LiveBundles[Bundles->getBundle(BC.Number, 0)] !=
(BC.Entry == SpillPlacement::PrefReg);
// Broken exit preference?
Inserts += LiveBundles[Bundles->getBundle(BC.Number, 1)] !=
(BC.Exit == SpillPlacement::PrefReg);
if (Inserts)
GlobalCost +=
Inserts * SpillPlacer->getBlockFrequency(SA->LiveBlocks[i].MBB);
}
DEBUG(dbgs() << "Global cost = " << GlobalCost << '\n');
return GlobalCost;
}
/// splitAroundRegion - Split VirtReg around the region determined by
/// LiveBundles. Make an effort to avoid interference from PhysReg.
///
/// The 'register' interval is going to contain as many uses as possible while
/// avoiding interference. The 'stack' interval is the complement constructed by
/// SplitEditor. It will contain the rest.
///
void RAGreedy::splitAroundRegion(LiveInterval &VirtReg, unsigned PhysReg,
const BitVector &LiveBundles,
SmallVectorImpl<LiveInterval*> &NewVRegs) {
DEBUG({
dbgs() << "Splitting around region for " << PrintReg(PhysReg, TRI)
<< " with bundles";
for (int i = LiveBundles.find_first(); i>=0; i = LiveBundles.find_next(i))
dbgs() << " EB#" << i;
dbgs() << ".\n";
});
// First compute interference ranges in the live blocks.
typedef std::pair<SlotIndex, SlotIndex> IndexPair;
SmallVector<IndexPair, 8> InterferenceRanges;
InterferenceRanges.resize(SA->LiveBlocks.size());
for (const unsigned *AI = TRI->getOverlaps(PhysReg); *AI; ++AI) {
if (!query(VirtReg, *AI).checkInterference())
continue;
LiveIntervalUnion::SegmentIter IntI =
PhysReg2LiveUnion[*AI].find(VirtReg.beginIndex());
if (!IntI.valid())
continue;
for (unsigned i = 0, e = SA->LiveBlocks.size(); i != e; ++i) {
const SplitAnalysis::BlockInfo &BI = SA->LiveBlocks[i];
IndexPair &IP = InterferenceRanges[i];
SlotIndex Start, Stop;
tie(Start, Stop) = Indexes->getMBBRange(BI.MBB);
// Skip interference-free blocks.
if (IntI.start() >= Stop)
continue;
// First interference in block.
if (BI.LiveIn) {
IntI.advanceTo(Start);
if (!IntI.valid())
break;
if (IntI.start() >= Stop)
continue;
if (!IP.first.isValid() || IntI.start() < IP.first)
IP.first = IntI.start();
}
// Last interference in block.
if (BI.LiveOut) {
IntI.advanceTo(Stop);
if (!IntI.valid() || IntI.start() >= Stop)
--IntI;
if (IntI.stop() <= Start)
continue;
if (!IP.second.isValid() || IntI.stop() > IP.second)
IP.second = IntI.stop();
}
}
}
SmallVector<LiveInterval*, 4> SpillRegs;
LiveRangeEdit LREdit(VirtReg, NewVRegs, SpillRegs);
SplitEditor SE(*SA, *LIS, *VRM, *DomTree, LREdit);
// Create the main cross-block interval.
SE.openIntv();
// First add all defs that are live out of a block.
for (unsigned i = 0, e = SA->LiveBlocks.size(); i != e; ++i) {
SplitAnalysis::BlockInfo &BI = SA->LiveBlocks[i];
bool RegIn = LiveBundles[Bundles->getBundle(BI.MBB->getNumber(), 0)];
bool RegOut = LiveBundles[Bundles->getBundle(BI.MBB->getNumber(), 1)];
// Should the register be live out?
if (!BI.LiveOut || !RegOut)
continue;
IndexPair &IP = InterferenceRanges[i];
SlotIndex Start, Stop;
tie(Start, Stop) = Indexes->getMBBRange(BI.MBB);
DEBUG(dbgs() << "BB#" << BI.MBB->getNumber() << " -> EB#"
<< Bundles->getBundle(BI.MBB->getNumber(), 1)
<< " intf [" << IP.first << ';' << IP.second << ')');
// The interference interval should either be invalid or overlap MBB.
assert((!IP.first.isValid() || IP.first < Stop) && "Bad interference");
assert((!IP.second.isValid() || IP.second > Start) && "Bad interference");
// Check interference leaving the block.
if (!IP.second.isValid()) {
// Block is interference-free.
DEBUG(dbgs() << ", no interference");
if (!BI.Uses) {
assert(BI.LiveThrough && "No uses, but not live through block?");
// Block is live-through without interference.
DEBUG(dbgs() << ", no uses"
<< (RegIn ? ", live-through.\n" : ", stack in.\n"));
if (!RegIn)
SE.enterIntvAtEnd(*BI.MBB);
continue;
}
if (!BI.LiveThrough) {
DEBUG(dbgs() << ", not live-through.\n");
SE.useIntv(SE.enterIntvBefore(BI.Def), Stop);
continue;
}
if (!RegIn) {
// Block is live-through, but entry bundle is on the stack.
// Reload just before the first use.
DEBUG(dbgs() << ", not live-in, enter before first use.\n");
SE.useIntv(SE.enterIntvBefore(BI.FirstUse), Stop);
continue;
}
DEBUG(dbgs() << ", live-through.\n");
continue;
}
// Block has interference.
DEBUG(dbgs() << ", interference to " << IP.second);
if (!BI.LiveThrough && IP.second <= BI.Def) {
// The interference doesn't reach the outgoing segment.
DEBUG(dbgs() << " doesn't affect def from " << BI.Def << '\n');
SE.useIntv(BI.Def, Stop);
continue;
}
if (!BI.Uses) {
// No uses in block, avoid interference by reloading as late as possible.
DEBUG(dbgs() << ", no uses.\n");
SlotIndex SegStart = SE.enterIntvAtEnd(*BI.MBB);
assert(SegStart >= IP.second && "Couldn't avoid interference");
continue;
}
if (IP.second.getBoundaryIndex() < BI.LastUse) {
// There are interference-free uses at the end of the block.
// Find the first use that can get the live-out register.
SmallVectorImpl<SlotIndex>::const_iterator UI =
std::lower_bound(SA->UseSlots.begin(), SA->UseSlots.end(),
IP.second.getBoundaryIndex());
assert(UI != SA->UseSlots.end() && "Couldn't find last use");
SlotIndex Use = *UI;
assert(Use <= BI.LastUse && "Couldn't find last use");
// Only attempt a split befroe the last split point.
if (Use.getBaseIndex() <= BI.LastSplitPoint) {
DEBUG(dbgs() << ", free use at " << Use << ".\n");
SlotIndex SegStart = SE.enterIntvBefore(Use);
assert(SegStart >= IP.second && "Couldn't avoid interference");
assert(SegStart < BI.LastSplitPoint && "Impossible split point");
SE.useIntv(SegStart, Stop);
continue;
}
}
// Interference is after the last use.
DEBUG(dbgs() << " after last use.\n");
SlotIndex SegStart = SE.enterIntvAtEnd(*BI.MBB);
assert(SegStart >= IP.second && "Couldn't avoid interference");
}
// Now all defs leading to live bundles are handled, do everything else.
for (unsigned i = 0, e = SA->LiveBlocks.size(); i != e; ++i) {
SplitAnalysis::BlockInfo &BI = SA->LiveBlocks[i];
bool RegIn = LiveBundles[Bundles->getBundle(BI.MBB->getNumber(), 0)];
bool RegOut = LiveBundles[Bundles->getBundle(BI.MBB->getNumber(), 1)];
// Is the register live-in?
if (!BI.LiveIn || !RegIn)
continue;
// We have an incoming register. Check for interference.
IndexPair &IP = InterferenceRanges[i];
SlotIndex Start, Stop;
tie(Start, Stop) = Indexes->getMBBRange(BI.MBB);
DEBUG(dbgs() << "EB#" << Bundles->getBundle(BI.MBB->getNumber(), 0)
<< " -> BB#" << BI.MBB->getNumber());
// Check interference entering the block.
if (!IP.first.isValid()) {
// Block is interference-free.
DEBUG(dbgs() << ", no interference");
if (!BI.Uses) {
assert(BI.LiveThrough && "No uses, but not live through block?");
// Block is live-through without interference.
if (RegOut) {
DEBUG(dbgs() << ", no uses, live-through.\n");
SE.useIntv(Start, Stop);
} else {
DEBUG(dbgs() << ", no uses, stack-out.\n");
SE.leaveIntvAtTop(*BI.MBB);
}
continue;
}
if (!BI.LiveThrough) {
DEBUG(dbgs() << ", killed in block.\n");
SE.useIntv(Start, SE.leaveIntvAfter(BI.Kill));
continue;
}
if (!RegOut) {
// Block is live-through, but exit bundle is on the stack.
// Spill immediately after the last use.
if (BI.LastUse < BI.LastSplitPoint) {
DEBUG(dbgs() << ", uses, stack-out.\n");
SE.useIntv(Start, SE.leaveIntvAfter(BI.LastUse));
continue;
}
// The last use is after the last split point, it is probably an
// indirect jump.
DEBUG(dbgs() << ", uses at " << BI.LastUse << " after split point "
<< BI.LastSplitPoint << ", stack-out.\n");
SlotIndex SegEnd = SE.leaveIntvBefore(BI.LastSplitPoint);
SE.useIntv(Start, SegEnd);
// Run a double interval from the split to the last use.
// This makes it possible to spill the complement without affecting the
// indirect branch.
SE.overlapIntv(SegEnd, BI.LastUse);
continue;
}
// Register is live-through.
DEBUG(dbgs() << ", uses, live-through.\n");
SE.useIntv(Start, Stop);
continue;
}
// Block has interference.
DEBUG(dbgs() << ", interference from " << IP.first);
if (!BI.LiveThrough && IP.first >= BI.Kill) {
// The interference doesn't reach the outgoing segment.
DEBUG(dbgs() << " doesn't affect kill at " << BI.Kill << '\n');
SE.useIntv(Start, BI.Kill);
continue;
}
if (!BI.Uses) {
// No uses in block, avoid interference by spilling as soon as possible.
DEBUG(dbgs() << ", no uses.\n");
SlotIndex SegEnd = SE.leaveIntvAtTop(*BI.MBB);
assert(SegEnd <= IP.first && "Couldn't avoid interference");
continue;
}
if (IP.first.getBaseIndex() > BI.FirstUse) {
// There are interference-free uses at the beginning of the block.
// Find the last use that can get the register.
SmallVectorImpl<SlotIndex>::const_iterator UI =
std::lower_bound(SA->UseSlots.begin(), SA->UseSlots.end(),
IP.first.getBaseIndex());
assert(UI != SA->UseSlots.begin() && "Couldn't find first use");
SlotIndex Use = (--UI)->getBoundaryIndex();
DEBUG(dbgs() << ", free use at " << *UI << ".\n");
SlotIndex SegEnd = SE.leaveIntvAfter(Use);
assert(SegEnd <= IP.first && "Couldn't avoid interference");
SE.useIntv(Start, SegEnd);
continue;
}
// Interference is before the first use.
DEBUG(dbgs() << " before first use.\n");
SlotIndex SegEnd = SE.leaveIntvAtTop(*BI.MBB);
assert(SegEnd <= IP.first && "Couldn't avoid interference");
}
SE.closeIntv();
// FIXME: Should we be more aggressive about splitting the stack region into
// per-block segments? The current approach allows the stack region to
// separate into connected components. Some components may be allocatable.
SE.finish();
++NumGlobalSplits;
if (VerifyEnabled) {
MF->verify(this, "After splitting live range around region");
#ifndef NDEBUG
// Make sure that at least one of the new intervals can allocate to PhysReg.
// That was the whole point of splitting the live range.
bool found = false;
for (LiveRangeEdit::iterator I = LREdit.begin(), E = LREdit.end(); I != E;
++I)
if (!checkUncachedInterference(**I, PhysReg)) {
found = true;
break;
}
assert(found && "No allocatable intervals after pointless splitting");
#endif
}
}
unsigned RAGreedy::tryRegionSplit(LiveInterval &VirtReg, AllocationOrder &Order,
SmallVectorImpl<LiveInterval*> &NewVRegs) {
BitVector LiveBundles, BestBundles;
float BestCost = 0;
unsigned BestReg = 0;
Order.rewind();
while (unsigned PhysReg = Order.next()) {
float Cost = calcInterferenceInfo(VirtReg, PhysReg);
if (BestReg && Cost >= BestCost)
continue;
SpillPlacer->placeSpills(SpillConstraints, LiveBundles);
// No live bundles, defer to splitSingleBlocks().
if (!LiveBundles.any())
continue;
Cost += calcGlobalSplitCost(LiveBundles);
if (!BestReg || Cost < BestCost) {
BestReg = PhysReg;
BestCost = Cost;
BestBundles.swap(LiveBundles);
}
}
if (!BestReg)
return 0;
splitAroundRegion(VirtReg, BestReg, BestBundles, NewVRegs);
return 0;
}
//===----------------------------------------------------------------------===//
// Local Splitting
//===----------------------------------------------------------------------===//
/// calcGapWeights - Compute the maximum spill weight that needs to be evicted
/// in order to use PhysReg between two entries in SA->UseSlots.
///
/// GapWeight[i] represents the gap between UseSlots[i] and UseSlots[i+1].
///
void RAGreedy::calcGapWeights(unsigned PhysReg,
SmallVectorImpl<float> &GapWeight) {
assert(SA->LiveBlocks.size() == 1 && "Not a local interval");
const SplitAnalysis::BlockInfo &BI = SA->LiveBlocks.front();
const SmallVectorImpl<SlotIndex> &Uses = SA->UseSlots;
const unsigned NumGaps = Uses.size()-1;
// Start and end points for the interference check.
SlotIndex StartIdx = BI.LiveIn ? BI.FirstUse.getBaseIndex() : BI.FirstUse;
SlotIndex StopIdx = BI.LiveOut ? BI.LastUse.getBoundaryIndex() : BI.LastUse;
GapWeight.assign(NumGaps, 0.0f);
// Add interference from each overlapping register.
for (const unsigned *AI = TRI->getOverlaps(PhysReg); *AI; ++AI) {
if (!query(const_cast<LiveInterval&>(SA->getParent()), *AI)
.checkInterference())
continue;
// We know that VirtReg is a continuous interval from FirstUse to LastUse,
// so we don't need InterferenceQuery.
//
// Interference that overlaps an instruction is counted in both gaps
// surrounding the instruction. The exception is interference before
// StartIdx and after StopIdx.
//
LiveIntervalUnion::SegmentIter IntI = PhysReg2LiveUnion[*AI].find(StartIdx);
for (unsigned Gap = 0; IntI.valid() && IntI.start() < StopIdx; ++IntI) {
// Skip the gaps before IntI.
while (Uses[Gap+1].getBoundaryIndex() < IntI.start())
if (++Gap == NumGaps)
break;
if (Gap == NumGaps)
break;
// Update the gaps covered by IntI.
const float weight = IntI.value()->weight;
for (; Gap != NumGaps; ++Gap) {
GapWeight[Gap] = std::max(GapWeight[Gap], weight);
if (Uses[Gap+1].getBaseIndex() >= IntI.stop())
break;
}
if (Gap == NumGaps)
break;
}
}
}
/// getPrevMappedIndex - Return the slot index of the last non-copy instruction
/// before MI that has a slot index. If MI is the first mapped instruction in
/// its block, return the block start index instead.
///
SlotIndex RAGreedy::getPrevMappedIndex(const MachineInstr *MI) {
assert(MI && "Missing MachineInstr");
const MachineBasicBlock *MBB = MI->getParent();
MachineBasicBlock::const_iterator B = MBB->begin(), I = MI;
while (I != B)
if (!(--I)->isDebugValue() && !I->isCopy())
return Indexes->getInstructionIndex(I);
return Indexes->getMBBStartIdx(MBB);
}
/// calcPrevSlots - Fill in the PrevSlot array with the index of the previous
/// real non-copy instruction for each instruction in SA->UseSlots.
///
void RAGreedy::calcPrevSlots() {
const SmallVectorImpl<SlotIndex> &Uses = SA->UseSlots;
PrevSlot.clear();
PrevSlot.reserve(Uses.size());
for (unsigned i = 0, e = Uses.size(); i != e; ++i) {
const MachineInstr *MI = Indexes->getInstructionFromIndex(Uses[i]);
PrevSlot.push_back(getPrevMappedIndex(MI).getDefIndex());
}
}
/// nextSplitPoint - Find the next index into SA->UseSlots > i such that it may
/// be beneficial to split before UseSlots[i].
///
/// 0 is always a valid split point
unsigned RAGreedy::nextSplitPoint(unsigned i) {
const SmallVectorImpl<SlotIndex> &Uses = SA->UseSlots;
const unsigned Size = Uses.size();
assert(i != Size && "No split points after the end");
// Allow split before i when Uses[i] is not adjacent to the previous use.
while (++i != Size && PrevSlot[i].getBaseIndex() <= Uses[i-1].getBaseIndex())
;
return i;
}
/// tryLocalSplit - Try to split VirtReg into smaller intervals inside its only
/// basic block.
///
unsigned RAGreedy::tryLocalSplit(LiveInterval &VirtReg, AllocationOrder &Order,
SmallVectorImpl<LiveInterval*> &NewVRegs) {
assert(SA->LiveBlocks.size() == 1 && "Not a local interval");
const SplitAnalysis::BlockInfo &BI = SA->LiveBlocks.front();
// Note that it is possible to have an interval that is live-in or live-out
// while only covering a single block - A phi-def can use undef values from
// predecessors, and the block could be a single-block loop.
// We don't bother doing anything clever about such a case, we simply assume
// that the interval is continuous from FirstUse to LastUse. We should make
// sure that we don't do anything illegal to such an interval, though.
const SmallVectorImpl<SlotIndex> &Uses = SA->UseSlots;
if (Uses.size() <= 2)
return 0;
const unsigned NumGaps = Uses.size()-1;
DEBUG({
dbgs() << "tryLocalSplit: ";
for (unsigned i = 0, e = Uses.size(); i != e; ++i)
dbgs() << ' ' << SA->UseSlots[i];
dbgs() << '\n';
});
// For every use, find the previous mapped non-copy instruction.
// We use this to detect valid split points, and to estimate new interval
// sizes.
calcPrevSlots();
unsigned BestBefore = NumGaps;
unsigned BestAfter = 0;
float BestDiff = 0;
const float blockFreq = SpillPlacer->getBlockFrequency(BI.MBB);
SmallVector<float, 8> GapWeight;
Order.rewind();
while (unsigned PhysReg = Order.next()) {
// Keep track of the largest spill weight that would need to be evicted in
// order to make use of PhysReg between UseSlots[i] and UseSlots[i+1].
calcGapWeights(PhysReg, GapWeight);
// Try to find the best sequence of gaps to close.
// The new spill weight must be larger than any gap interference.
// We will split before Uses[SplitBefore] and after Uses[SplitAfter].
unsigned SplitBefore = 0, SplitAfter = nextSplitPoint(1) - 1;
// MaxGap should always be max(GapWeight[SplitBefore..SplitAfter-1]).
// It is the spill weight that needs to be evicted.
float MaxGap = GapWeight[0];
for (unsigned i = 1; i != SplitAfter; ++i)
MaxGap = std::max(MaxGap, GapWeight[i]);
for (;;) {
// Live before/after split?
const bool LiveBefore = SplitBefore != 0 || BI.LiveIn;
const bool LiveAfter = SplitAfter != NumGaps || BI.LiveOut;
DEBUG(dbgs() << PrintReg(PhysReg, TRI) << ' '
<< Uses[SplitBefore] << '-' << Uses[SplitAfter]
<< " i=" << MaxGap);
// Stop before the interval gets so big we wouldn't be making progress.
if (!LiveBefore && !LiveAfter) {
DEBUG(dbgs() << " all\n");
break;
}
// Should the interval be extended or shrunk?
bool Shrink = true;
if (MaxGap < HUGE_VALF) {
// Estimate the new spill weight.
//
// Each instruction reads and writes the register, except the first
// instr doesn't read when !FirstLive, and the last instr doesn't write
// when !LastLive.
//
// We will be inserting copies before and after, so the total number of
// reads and writes is 2 * EstUses.
//
const unsigned EstUses = 2*(SplitAfter - SplitBefore) +
2*(LiveBefore + LiveAfter);
// Try to guess the size of the new interval. This should be trivial,
// but the slot index of an inserted copy can be a lot smaller than the
// instruction it is inserted before if there are many dead indexes
// between them.
//
// We measure the distance from the instruction before SplitBefore to
// get a conservative estimate.
//
// The final distance can still be different if inserting copies
// triggers a slot index renumbering.
//
const float EstWeight = normalizeSpillWeight(blockFreq * EstUses,
PrevSlot[SplitBefore].distance(Uses[SplitAfter]));
// Would this split be possible to allocate?
// Never allocate all gaps, we wouldn't be making progress.
float Diff = EstWeight - MaxGap;
DEBUG(dbgs() << " w=" << EstWeight << " d=" << Diff);
if (Diff > 0) {
Shrink = false;
if (Diff > BestDiff) {
DEBUG(dbgs() << " (best)");
BestDiff = Diff;
BestBefore = SplitBefore;
BestAfter = SplitAfter;
}
}
}
// Try to shrink.
if (Shrink) {
SplitBefore = nextSplitPoint(SplitBefore);
if (SplitBefore < SplitAfter) {
DEBUG(dbgs() << " shrink\n");
// Recompute the max when necessary.
if (GapWeight[SplitBefore - 1] >= MaxGap) {
MaxGap = GapWeight[SplitBefore];
for (unsigned i = SplitBefore + 1; i != SplitAfter; ++i)
MaxGap = std::max(MaxGap, GapWeight[i]);
}
continue;
}
MaxGap = 0;
}
// Try to extend the interval.
if (SplitAfter >= NumGaps) {
DEBUG(dbgs() << " end\n");
break;
}
DEBUG(dbgs() << " extend\n");
for (unsigned e = nextSplitPoint(SplitAfter + 1) - 1;
SplitAfter != e; ++SplitAfter)
MaxGap = std::max(MaxGap, GapWeight[SplitAfter]);
continue;
}
}
// Didn't find any candidates?
if (BestBefore == NumGaps)
return 0;
DEBUG(dbgs() << "Best local split range: " << Uses[BestBefore]
<< '-' << Uses[BestAfter] << ", " << BestDiff
<< ", " << (BestAfter - BestBefore + 1) << " instrs\n");
SmallVector<LiveInterval*, 4> SpillRegs;
LiveRangeEdit LREdit(VirtReg, NewVRegs, SpillRegs);
SplitEditor SE(*SA, *LIS, *VRM, *DomTree, LREdit);
SE.openIntv();
SlotIndex SegStart = SE.enterIntvBefore(Uses[BestBefore]);
SlotIndex SegStop = SE.leaveIntvAfter(Uses[BestAfter]);
SE.useIntv(SegStart, SegStop);
SE.closeIntv();
SE.finish();
++NumLocalSplits;
return 0;
}
//===----------------------------------------------------------------------===//
// Live Range Splitting
//===----------------------------------------------------------------------===//
/// trySplit - Try to split VirtReg or one of its interferences, making it
/// assignable.
/// @return Physreg when VirtReg may be assigned and/or new NewVRegs.
unsigned RAGreedy::trySplit(LiveInterval &VirtReg, AllocationOrder &Order,
SmallVectorImpl<LiveInterval*>&NewVRegs) {
SA->analyze(&VirtReg);
// Local intervals are handled separately.
if (LIS->intervalIsInOneMBB(VirtReg)) {
NamedRegionTimer T("Local Splitting", TimerGroupName, TimePassesIsEnabled);
return tryLocalSplit(VirtReg, Order, NewVRegs);
}
NamedRegionTimer T("Global Splitting", TimerGroupName, TimePassesIsEnabled);
// First try to split around a region spanning multiple blocks.
unsigned PhysReg = tryRegionSplit(VirtReg, Order, NewVRegs);
if (PhysReg || !NewVRegs.empty())
return PhysReg;
// Then isolate blocks with multiple uses.
SplitAnalysis::BlockPtrSet Blocks;
if (SA->getMultiUseBlocks(Blocks)) {
SmallVector<LiveInterval*, 4> SpillRegs;
LiveRangeEdit LREdit(VirtReg, NewVRegs, SpillRegs);
SplitEditor(*SA, *LIS, *VRM, *DomTree, LREdit).splitSingleBlocks(Blocks);
if (VerifyEnabled)
MF->verify(this, "After splitting live range around basic blocks");
}
// Don't assign any physregs.
return 0;
}
//===----------------------------------------------------------------------===//
// Spilling
//===----------------------------------------------------------------------===//
/// calcInterferenceWeight - Calculate the combined spill weight of
/// interferences when assigning VirtReg to PhysReg.
float RAGreedy::calcInterferenceWeight(LiveInterval &VirtReg, unsigned PhysReg){
float Sum = 0;
for (const unsigned *AI = TRI->getOverlaps(PhysReg); *AI; ++AI) {
LiveIntervalUnion::Query &Q = query(VirtReg, *AI);
Q.collectInterferingVRegs();
if (Q.seenUnspillableVReg())
return HUGE_VALF;
for (unsigned i = 0, e = Q.interferingVRegs().size(); i != e; ++i)
Sum += Q.interferingVRegs()[i]->weight;
}
return Sum;
}
/// trySpillInterferences - Try to spill interfering registers instead of the
/// current one. Only do it if the accumulated spill weight is smaller than the
/// current spill weight.
unsigned RAGreedy::trySpillInterferences(LiveInterval &VirtReg,
AllocationOrder &Order,
SmallVectorImpl<LiveInterval*> &NewVRegs) {
NamedRegionTimer T("Spill Interference", TimerGroupName, TimePassesIsEnabled);
unsigned BestPhys = 0;
float BestWeight = 0;
Order.rewind();
while (unsigned PhysReg = Order.next()) {
float Weight = calcInterferenceWeight(VirtReg, PhysReg);
if (Weight == HUGE_VALF || Weight >= VirtReg.weight)
continue;
if (!BestPhys || Weight < BestWeight)
BestPhys = PhysReg, BestWeight = Weight;
}
// No candidates found.
if (!BestPhys)
return 0;
// Collect all interfering registers.
SmallVector<LiveInterval*, 8> Spills;
for (const unsigned *AI = TRI->getOverlaps(BestPhys); *AI; ++AI) {
LiveIntervalUnion::Query &Q = query(VirtReg, *AI);
Spills.append(Q.interferingVRegs().begin(), Q.interferingVRegs().end());
for (unsigned i = 0, e = Q.interferingVRegs().size(); i != e; ++i) {
LiveInterval *VReg = Q.interferingVRegs()[i];
unassign(*VReg, *AI);
}
}
// Spill them all.
DEBUG(dbgs() << "spilling " << Spills.size() << " interferences with weight "
<< BestWeight << '\n');
for (unsigned i = 0, e = Spills.size(); i != e; ++i)
spiller().spill(Spills[i], NewVRegs, Spills);
return BestPhys;
}
//===----------------------------------------------------------------------===//
// Main Entry Point
//===----------------------------------------------------------------------===//
unsigned RAGreedy::selectOrSplit(LiveInterval &VirtReg,
SmallVectorImpl<LiveInterval*> &NewVRegs) {
// First try assigning a free register.
AllocationOrder Order(VirtReg.reg, *VRM, ReservedRegs);
while (unsigned PhysReg = Order.next()) {
if (!checkPhysRegInterference(VirtReg, PhysReg))
return PhysReg;
}
// Try to reassign interferences.
if (unsigned PhysReg = tryReassignOrEvict(VirtReg, Order, NewVRegs))
return PhysReg;
assert(NewVRegs.empty() && "Cannot append to existing NewVRegs");
// Try splitting VirtReg or interferences.
unsigned PhysReg = trySplit(VirtReg, Order, NewVRegs);
if (PhysReg || !NewVRegs.empty())
return PhysReg;
// Try to spill another interfering reg with less spill weight.
PhysReg = trySpillInterferences(VirtReg, Order, NewVRegs);
if (PhysReg)
return PhysReg;
// Finally spill VirtReg itself.
NamedRegionTimer T("Spiller", TimerGroupName, TimePassesIsEnabled);
SmallVector<LiveInterval*, 1> pendingSpills;
spiller().spill(&VirtReg, NewVRegs, pendingSpills);
// The live virtual register requesting allocation was spilled, so tell
// the caller not to allocate anything during this round.
return 0;
}
bool RAGreedy::runOnMachineFunction(MachineFunction &mf) {
DEBUG(dbgs() << "********** GREEDY REGISTER ALLOCATION **********\n"
<< "********** Function: "
<< ((Value*)mf.getFunction())->getName() << '\n');
MF = &mf;
if (VerifyEnabled)
MF->verify(this, "Before greedy register allocator");
RegAllocBase::init(getAnalysis<VirtRegMap>(), getAnalysis<LiveIntervals>());
Indexes = &getAnalysis<SlotIndexes>();
DomTree = &getAnalysis<MachineDominatorTree>();
ReservedRegs = TRI->getReservedRegs(*MF);
SpillerInstance.reset(createInlineSpiller(*this, *MF, *VRM));
Loops = &getAnalysis<MachineLoopInfo>();
LoopRanges = &getAnalysis<MachineLoopRanges>();
Bundles = &getAnalysis<EdgeBundles>();
SpillPlacer = &getAnalysis<SpillPlacement>();
SA.reset(new SplitAnalysis(*VRM, *LIS, *Loops));
allocatePhysRegs();
addMBBLiveIns(MF);
LIS->addKillFlags();
// Run rewriter
{
NamedRegionTimer T("Rewriter", TimerGroupName, TimePassesIsEnabled);
VRM->rewrite(Indexes);
}
// The pass output is in VirtRegMap. Release all the transient data.
releaseMemory();
return true;
}
Reference in New Issue View Git Blame Copy Permalink