#include "SplitKit.h"
#include "LiveRangeEdit.h"
#include "VirtRegMap.h"
-#include "llvm/CodeGen/CalcSpillWeights.h"
+#include "llvm/ADT/Statistic.h"
#include "llvm/CodeGen/LiveIntervalAnalysis.h"
#include "llvm/CodeGen/MachineDominators.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
-#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Debug.h"
#include "llvm/Support/raw_ostream.h"
#include "llvm/Target/TargetInstrInfo.h"
using namespace llvm;
-static cl::opt<bool>
-AllowSplit("spiller-splits-edges",
- cl::desc("Allow critical edge splitting during spilling"));
+STATISTIC(NumFinished, "Number of splits finished");
+STATISTIC(NumSimple, "Number of splits that were simple");
+STATISTIC(NumCopies, "Number of copies inserted for splitting");
+STATISTIC(NumRemats, "Number of rematerialized defs for splitting");
+STATISTIC(NumRepairs, "Number of invalid live ranges repaired");
//===----------------------------------------------------------------------===//
// Split Analysis
LIS(lis),
Loops(mli),
TII(*MF.getTarget().getInstrInfo()),
- CurLI(0) {}
+ CurLI(0),
+ LastSplitPoint(MF.getNumBlockIDs()) {}
void SplitAnalysis::clear() {
UseSlots.clear();
- UsingInstrs.clear();
- UsingBlocks.clear();
- LiveBlocks.clear();
+ UseBlocks.clear();
+ ThroughBlocks.clear();
CurLI = 0;
+ DidRepairRange = false;
}
-bool SplitAnalysis::canAnalyzeBranch(const MachineBasicBlock *MBB) {
- MachineBasicBlock *T, *F;
- SmallVector<MachineOperand, 4> Cond;
- return !TII.AnalyzeBranch(const_cast<MachineBasicBlock&>(*MBB), T, F, Cond);
+SlotIndex SplitAnalysis::computeLastSplitPoint(unsigned Num) {
+ const MachineBasicBlock *MBB = MF.getBlockNumbered(Num);
+ const MachineBasicBlock *LPad = MBB->getLandingPadSuccessor();
+ std::pair<SlotIndex, SlotIndex> &LSP = LastSplitPoint[Num];
+
+ // Compute split points on the first call. The pair is independent of the
+ // current live interval.
+ if (!LSP.first.isValid()) {
+ MachineBasicBlock::const_iterator FirstTerm = MBB->getFirstTerminator();
+ if (FirstTerm == MBB->end())
+ LSP.first = LIS.getMBBEndIdx(MBB);
+ else
+ LSP.first = LIS.getInstructionIndex(FirstTerm);
+
+ // If there is a landing pad successor, also find the call instruction.
+ if (!LPad)
+ return LSP.first;
+ // There may not be a call instruction (?) in which case we ignore LPad.
+ LSP.second = LSP.first;
+ for (MachineBasicBlock::const_iterator I = FirstTerm, E = MBB->begin();
+ I != E; --I)
+ if (I->getDesc().isCall()) {
+ LSP.second = LIS.getInstructionIndex(I);
+ break;
+ }
+ }
+
+ // If CurLI is live into a landing pad successor, move the last split point
+ // back to the call that may throw.
+ if (LPad && LSP.second.isValid() && LIS.isLiveInToMBB(*CurLI, LPad))
+ return LSP.second;
+ else
+ return LSP.first;
}
/// analyzeUses - Count instructions, basic blocks, and loops using CurLI.
void SplitAnalysis::analyzeUses() {
+ assert(UseSlots.empty() && "Call clear first");
+
+ // First get all the defs from the interval values. This provides the correct
+ // slots for early clobbers.
+ for (LiveInterval::const_vni_iterator I = CurLI->vni_begin(),
+ E = CurLI->vni_end(); I != E; ++I)
+ if (!(*I)->isPHIDef() && !(*I)->isUnused())
+ UseSlots.push_back((*I)->def);
+
+ // Get use slots form the use-def chain.
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;
- MachineInstr *MI = MO.getParent();
- if (MI->isDebugValue() || !UsingInstrs.insert(MI))
- continue;
- UseSlots.push_back(LIS.getInstructionIndex(MI).getDefIndex());
- MachineBasicBlock *MBB = MI->getParent();
- UsingBlocks[MBB]++;
- }
+ for (MachineRegisterInfo::use_nodbg_iterator
+ I = MRI.use_nodbg_begin(CurLI->reg), E = MRI.use_nodbg_end(); I != E;
+ ++I)
+ if (!I.getOperand().isUndef())
+ UseSlots.push_back(LIS.getInstructionIndex(&*I).getDefIndex());
+
array_pod_sort(UseSlots.begin(), UseSlots.end());
- calcLiveBlockInfo();
- DEBUG(dbgs() << " counted "
- << UsingInstrs.size() << " instrs, "
- << UsingBlocks.size() << " blocks.\n");
+
+ // Remove duplicates, keeping the smaller slot for each instruction.
+ // That is what we want for early clobbers.
+ UseSlots.erase(std::unique(UseSlots.begin(), UseSlots.end(),
+ SlotIndex::isSameInstr),
+ UseSlots.end());
+
+ // Compute per-live block info.
+ if (!calcLiveBlockInfo()) {
+ // FIXME: calcLiveBlockInfo found inconsistencies in the live range.
+ // I am looking at you, SimpleRegisterCoalescing!
+ DidRepairRange = true;
+ ++NumRepairs;
+ DEBUG(dbgs() << "*** Fixing inconsistent live interval! ***\n");
+ const_cast<LiveIntervals&>(LIS)
+ .shrinkToUses(const_cast<LiveInterval*>(CurLI));
+ UseBlocks.clear();
+ ThroughBlocks.clear();
+ bool fixed = calcLiveBlockInfo();
+ (void)fixed;
+ assert(fixed && "Couldn't fix broken live interval");
+ }
+
+ DEBUG(dbgs() << "Analyze counted "
+ << UseSlots.size() << " instrs in "
+ << UseBlocks.size() << " blocks, through "
+ << NumThroughBlocks << " blocks.\n");
}
/// calcLiveBlockInfo - Fill the LiveBlocks array with information about blocks
/// where CurLI is live.
-void SplitAnalysis::calcLiveBlockInfo() {
+bool SplitAnalysis::calcLiveBlockInfo() {
+ ThroughBlocks.resize(MF.getNumBlockIDs());
+ NumThroughBlocks = NumGapBlocks = 0;
if (CurLI->empty())
- return;
+ return true;
LiveInterval::const_iterator LVI = CurLI->begin();
LiveInterval::const_iterator LVE = CurLI->end();
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) {
+ // If the block contains no uses, the range must be live through. At one
+ // point, SimpleRegisterCoalescing could create dangling ranges that ended
+ // mid-block.
+ if (UseI == UseE || *UseI >= Stop) {
+ ++NumThroughBlocks;
+ ThroughBlocks.set(BI.MBB->getNumber());
+ // The range shouldn't end mid-block if there are no uses. This shouldn't
+ // happen.
+ if (LVI->end < Stop)
+ return false;
+ } else {
+ // This block has uses. Find the first and last uses in the block.
BI.FirstUse = *UseI;
assert(BI.FirstUse >= Start);
do ++UseI;
while (UseI != UseE && *UseI < Stop);
BI.LastUse = UseI[-1];
assert(BI.LastUse < Stop);
- }
- // 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;
+ // LVI is the first live segment overlapping MBB.
+ BI.LiveIn = LVI->start <= Start;
+
+ // Look for gaps in the live range.
+ BI.LiveOut = true;
+ while (LVI->end < Stop) {
+ SlotIndex LastStop = LVI->end;
+ if (++LVI == LVE || LVI->start >= Stop) {
+ BI.LiveOut = false;
+ BI.LastUse = LastStop;
+ break;
+ }
+ if (LastStop < LVI->start) {
+ // There is a gap in the live range. Create duplicate entries for the
+ // live-in snippet and the live-out snippet.
+ ++NumGapBlocks;
+
+ // Push the Live-in part.
+ BI.LiveThrough = false;
+ BI.LiveOut = false;
+ UseBlocks.push_back(BI);
+ UseBlocks.back().LastUse = LastStop;
+
+ // Set up BI for the live-out part.
+ BI.LiveIn = false;
+ BI.LiveOut = true;
+ BI.FirstUse = LVI->start;
+ }
}
- }
- // Don't set LiveThrough when the block has a gap.
- BI.LiveThrough = !hasGap && BI.LiveIn && BI.LiveOut;
- LiveBlocks.push_back(BI);
+ // Don't set LiveThrough when the block has a gap.
+ BI.LiveThrough = BI.LiveIn && BI.LiveOut;
+ UseBlocks.push_back(BI);
- // LVI is now at LVE or LVI->end >= Stop.
- if (LVI == LVE)
- break;
+ // LVI is now at LVE or LVI->end >= Stop.
+ if (LVI == LVE)
+ break;
+ }
// Live segment ends exactly at Stop. Move to the next segment.
if (LVI->end == Stop && ++LVI == LVE)
else
MFI = LIS.getMBBFromIndex(LVI->start);
}
+
+ assert(getNumLiveBlocks() == countLiveBlocks(CurLI) && "Bad block count");
+ return true;
+}
+
+unsigned SplitAnalysis::countLiveBlocks(const LiveInterval *cli) const {
+ if (cli->empty())
+ return 0;
+ LiveInterval *li = const_cast<LiveInterval*>(cli);
+ LiveInterval::iterator LVI = li->begin();
+ LiveInterval::iterator LVE = li->end();
+ unsigned Count = 0;
+
+ // Loop over basic blocks where li is live.
+ MachineFunction::const_iterator MFI = LIS.getMBBFromIndex(LVI->start);
+ SlotIndex Stop = LIS.getMBBEndIdx(MFI);
+ for (;;) {
+ ++Count;
+ LVI = li->advanceTo(LVI, Stop);
+ if (LVI == LVE)
+ return Count;
+ do {
+ ++MFI;
+ Stop = LIS.getMBBEndIdx(MFI);
+ } while (Stop <= LVI->start);
+ }
}
bool SplitAnalysis::isOriginalEndpoint(SlotIndex Idx) const {
return I != Orig.begin() && (--I)->end == Idx;
}
-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 << ')';
- }
-}
-
void SplitAnalysis::analyze(const LiveInterval *li) {
clear();
CurLI = li;
SplitEditor::SplitEditor(SplitAnalysis &sa,
LiveIntervals &lis,
VirtRegMap &vrm,
- MachineDominatorTree &mdt,
- LiveRangeEdit &edit)
+ MachineDominatorTree &mdt)
: SA(sa), LIS(lis), VRM(vrm),
MRI(vrm.getMachineFunction().getRegInfo()),
MDT(mdt),
TII(*vrm.getMachineFunction().getTarget().getInstrInfo()),
TRI(*vrm.getMachineFunction().getTarget().getRegisterInfo()),
- Edit(edit),
+ Edit(0),
OpenIdx(0),
RegAssign(Allocator)
-{
+{}
+
+void SplitEditor::reset(LiveRangeEdit &lre) {
+ Edit = &lre;
+ OpenIdx = 0;
+ RegAssign.clear();
+ Values.clear();
+
+ // We don't need to clear LiveOutCache, only LiveOutSeen entries are read.
+ LiveOutSeen.clear();
+
// We don't need an AliasAnalysis since we will only be performing
// cheap-as-a-copy remats anyway.
- Edit.anyRematerializable(LIS, TII, 0);
+ Edit->anyRematerializable(LIS, TII, 0);
}
void SplitEditor::dump() const {
SlotIndex Idx) {
assert(ParentVNI && "Mapping NULL value");
assert(Idx.isValid() && "Invalid SlotIndex");
- assert(Edit.getParent().getVNInfoAt(Idx) == ParentVNI && "Bad Parent VNI");
- LiveInterval *LI = Edit.get(RegIdx);
+ assert(Edit->getParent().getVNInfoAt(Idx) == ParentVNI && "Bad Parent VNI");
+ LiveInterval *LI = Edit->get(RegIdx);
// 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(std::make_pair(std::make_pair(RegIdx, ParentVNI->id), VNI));
// This was previously a single mapping. Make sure the old def is represented
// by a trivial live range.
SlotIndex Def = VNI->def;
- Edit.get(RegIdx)->addRange(LiveRange(Def, Def.getNextSlot(), VNI));
+ Edit->get(RegIdx)->addRange(LiveRange(Def, Def.getNextSlot(), VNI));
VNI = 0;
}
assert(Idx.isValid() && "Invalid SlotIndex");
MachineBasicBlock *IdxMBB = LIS.getMBBFromIndex(Idx);
assert(IdxMBB && "No MBB at Idx");
- LiveInterval *LI = Edit.get(RegIdx);
+ LiveInterval *LI = Edit->get(RegIdx);
// Is there a def in the same MBB we can extend?
if (LI->extendInBlock(LIS.getMBBStartIdx(IdxMBB), 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 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');
+ // VNInfo.
+ VNInfo *VNI = findReachingDefs(LI, IdxMBB, Idx.getNextSlot());
+
+ // When there were multiple different values, we may need new PHIs.
+ if (!VNI)
+ return updateSSA();
+
+ // Poor man's SSA update for the single-value case.
+ LiveOutPair LOP(VNI, MDT[LIS.getMBBFromIndex(VNI->def)]);
+ for (SmallVectorImpl<LiveInBlock>::iterator I = LiveInBlocks.begin(),
+ E = LiveInBlocks.end(); I != E; ++I) {
+ MachineBasicBlock *MBB = I->DomNode->getBlock();
+ SlotIndex Start = LIS.getMBBStartIdx(MBB);
+ if (I->Kill.isValid())
+ LI->addRange(LiveRange(Start, I->Kill, VNI));
+ else {
+ LiveOutCache[MBB] = LOP;
+ LI->addRange(LiveRange(Start, LIS.getMBBEndIdx(MBB), VNI));
+ }
+ }
+}
+
+/// findReachingDefs - Search the CFG for known live-out values.
+/// Add required live-in blocks to LiveInBlocks.
+VNInfo *SplitEditor::findReachingDefs(LiveInterval *LI,
+ MachineBasicBlock *KillMBB,
+ SlotIndex Kill) {
+ // Initialize the live-out cache the first time it is needed.
+ if (LiveOutSeen.empty()) {
+ unsigned N = VRM.getMachineFunction().getNumBlockIDs();
+ LiveOutSeen.resize(N);
+ LiveOutCache.resize(N);
+ }
// Blocks where LI should be live-in.
- SmallVector<MachineDomTreeNode*, 16> LiveIn;
- LiveIn.push_back(MDT[IdxMBB]);
+ SmallVector<MachineBasicBlock*, 16> WorkList(1, KillMBB);
+
+ // Remember if we have seen more than one value.
+ bool UniqueVNI = true;
+ VNInfo *TheVNI = 0;
// 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 (unsigned i = 0; i != WorkList.size(); ++i) {
+ MachineBasicBlock *MBB = WorkList[i];
+ assert(!MBB->pred_empty() && "Value live-in to entry block?");
for (MachineBasicBlock::pred_iterator PI = MBB->pred_begin(),
PE = MBB->pred_end(); PI != PE; ++PI) {
MachineBasicBlock *Pred = *PI;
+ LiveOutPair &LOP = LiveOutCache[Pred];
+
// 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)
+ if (LiveOutSeen.test(Pred->getNumber())) {
+ if (VNInfo *VNI = LOP.first) {
+ if (TheVNI && TheVNI != VNI)
+ UniqueVNI = false;
+ TheVNI = VNI;
+ }
continue;
+ }
+
+ // First time. LOP is garbage and must be cleared below.
+ LiveOutSeen.set(Pred->getNumber());
// Does Pred provide a live-out value?
SlotIndex Start, Last;
tie(Start, Last) = LIS.getSlotIndexes()->getMBBRange(Pred);
Last = Last.getPrevSlot();
- if (VNInfo *VNI = LI->extendInBlock(Start, Last)) {
- MachineBasicBlock *DefMBB = LIS.getMBBFromIndex(VNI->def);
- LiveOutPair &LOP = LOIP.first->second;
- LOP.first = VNI;
- LOP.second = MDT[DefMBB];
+ VNInfo *VNI = LI->extendInBlock(Start, Last);
+ LOP.first = VNI;
+ if (VNI) {
+ LOP.second = MDT[LIS.getMBBFromIndex(VNI->def)];
+ if (TheVNI && TheVNI != VNI)
+ UniqueVNI = false;
+ TheVNI = VNI;
continue;
}
+ LOP.second = 0;
+
// No, we need a live-in value for Pred as well
- if (Pred != IdxMBB)
- LiveIn.push_back(MDT[Pred]);
+ if (Pred != KillMBB)
+ WorkList.push_back(Pred);
+ else
+ // Loopback to KillMBB, so value is really live through.
+ Kill = SlotIndex();
}
}
- // We may need to add phi-def values to preserve the SSA form.
- VNInfo *IdxVNI = updateSSA(RegIdx, LiveIn, Idx, IdxMBB);
+ // Transfer WorkList to LiveInBlocks in reverse order.
+ // This ordering works best with updateSSA().
+ LiveInBlocks.clear();
+ LiveInBlocks.reserve(WorkList.size());
+ while(!WorkList.empty())
+ LiveInBlocks.push_back(MDT[WorkList.pop_back_val()]);
-#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
+ // The kill block may not be live-through.
+ assert(LiveInBlocks.back().DomNode->getBlock() == KillMBB);
+ LiveInBlocks.back().Kill = Kill;
- // 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.
- 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));
- }
+ return UniqueVNI ? TheVNI : 0;
}
-VNInfo *SplitEditor::updateSSA(unsigned RegIdx,
- SmallVectorImpl<MachineDomTreeNode*> &LiveIn,
- SlotIndex Idx,
- const MachineBasicBlock *IdxMBB) {
+void SplitEditor::updateSSA() {
// 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.
- LiveInterval *LI = Edit.get(RegIdx);
- 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];
+ // when necessary.
+ for (SmallVectorImpl<LiveInBlock>::iterator I = LiveInBlocks.begin(),
+ E = LiveInBlocks.end(); I != E; ++I) {
+ MachineDomTreeNode *Node = I->DomNode;
+ // Skip block if the live-in value has already been determined.
+ if (!Node)
+ continue;
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;
+ bool needPHI = !IDom || !LiveOutSeen.test(IDom->getBlock()->getNumber());
- // 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;
- }
-
- // 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.
+ // IDom dominates all of our predecessors, but it may not be their
+ // 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) {
+ IDomValue = LiveOutCache[IDom->getBlock()];
for (MachineBasicBlock::pred_iterator PI = MBB->pred_begin(),
PE = MBB->pred_end(); PI != PE; ++PI) {
LiveOutPair Value = LiveOutCache[*PI];
}
}
+ // The value may be live-through even if Kill is set, as can happen when
+ // we are called from extendRange. In that case LiveOutSeen is true, and
+ // LiveOutCache indicates a foreign or missing value.
+ LiveOutPair &LOP = LiveOutCache[MBB];
+
// Create a phi-def if required.
if (needPHI) {
++Changes;
SlotIndex Start = LIS.getMBBStartIdx(MBB);
+ unsigned RegIdx = RegAssign.lookup(Start);
+ LiveInterval *LI = Edit->get(RegIdx);
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.
+ I->Value = VNI;
+ // This block is done, we know the final value.
+ I->DomNode = 0;
+ if (I->Kill.isValid())
+ LI->addRange(LiveRange(Start, I->Kill, VNI));
+ else {
LI->addRange(LiveRange(Start, LIS.getMBBEndIdx(MBB), VNI));
- I->second = LiveOutPair(VNI, Node);
+ LOP = LiveOutPair(VNI, Node);
}
} else if (IDomValue.first) {
- // No phi-def here. Remember incoming value for IdxMBB.
- if (MBB == IdxMBB)
- IdxVNI = IDomValue.first;
+ // No phi-def here. Remember incoming value.
+ I->Value = IDomValue.first;
+ if (I->Kill.isValid())
+ continue;
// 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) {
+ if (LOP.second != Node && LOP.first != IDomValue.first) {
++Changes;
- I->second = IDomValue;
- DEBUG(dbgs() << " - BB#" << MBB->getNumber()
- << " idom valno #" << IDomValue.first->id
- << " from BB#" << IDom->getBlock()->getNumber() << '\n');
+ LOP = IDomValue;
}
}
}
- DEBUG(dbgs() << " - made " << Changes << " changes.\n");
} while (Changes);
- assert(IdxVNI && "Didn't find value for Idx");
- return IdxVNI;
+ // The values in LiveInBlocks are now accurate. No more phi-defs are needed
+ // for these blocks, so we can color the live ranges.
+ for (SmallVectorImpl<LiveInBlock>::iterator I = LiveInBlocks.begin(),
+ E = LiveInBlocks.end(); I != E; ++I) {
+ if (!I->DomNode)
+ continue;
+ assert(I->Value && "No live-in value found");
+ MachineBasicBlock *MBB = I->DomNode->getBlock();
+ SlotIndex Start = LIS.getMBBStartIdx(MBB);
+ unsigned RegIdx = RegAssign.lookup(Start);
+ LiveInterval *LI = Edit->get(RegIdx);
+ LI->addRange(LiveRange(Start, I->Kill.isValid() ?
+ I->Kill : LIS.getMBBEndIdx(MBB), I->Value));
+ }
}
VNInfo *SplitEditor::defFromParent(unsigned RegIdx,
MachineBasicBlock::iterator I) {
MachineInstr *CopyMI = 0;
SlotIndex Def;
- LiveInterval *LI = Edit.get(RegIdx);
+ LiveInterval *LI = Edit->get(RegIdx);
+
+ // We may be trying to avoid interference that ends at a deleted instruction,
+ // so always begin RegIdx 0 early and all others late.
+ bool Late = RegIdx != 0;
// 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);
+ if (Edit->canRematerializeAt(RM, UseIdx, true, LIS)) {
+ Def = Edit->rematerializeAt(MBB, I, LI->reg, RM, LIS, TII, TRI, Late);
+ ++NumRemats;
} 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();
+ .addReg(Edit->getReg());
+ Def = LIS.getSlotIndexes()->insertMachineInstrInMaps(CopyMI, Late)
+ .getDefIndex();
+ ++NumCopies;
}
- // Temporarily mark all values as complex mapped.
- markComplexMapped(RegIdx, ParentVNI);
-
// Define the value in Reg.
VNInfo *VNI = defValue(RegIdx, ParentVNI, Def);
VNI->setCopy(CopyMI);
}
/// Create a new virtual register and live interval.
-void SplitEditor::openIntv() {
- assert(!OpenIdx && "Previous LI not closed before openIntv");
-
+unsigned SplitEditor::openIntv() {
// Create the complement as index 0.
- if (Edit.empty())
- Edit.create(MRI, LIS, VRM);
+ if (Edit->empty())
+ Edit->create(LIS, VRM);
// Create the open interval.
- OpenIdx = Edit.size();
- Edit.create(MRI, LIS, VRM);
+ OpenIdx = Edit->size();
+ Edit->create(LIS, VRM);
+ return OpenIdx;
+}
+
+void SplitEditor::selectIntv(unsigned Idx) {
+ assert(Idx != 0 && "Cannot select the complement interval");
+ assert(Idx < Edit->size() && "Can only select previously opened interval");
+ OpenIdx = Idx;
}
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);
+ VNInfo *ParentVNI = Edit->getParent().getVNInfoAt(Idx);
if (!ParentVNI) {
DEBUG(dbgs() << ": not live\n");
return Idx;
SlotIndex End = LIS.getMBBEndIdx(&MBB);
SlotIndex Last = End.getPrevSlot();
DEBUG(dbgs() << " enterIntvAtEnd BB#" << MBB.getNumber() << ", " << Last);
- VNInfo *ParentVNI = Edit.getParent().getVNInfoAt(Last);
+ VNInfo *ParentVNI = Edit->getParent().getVNInfoAt(Last);
if (!ParentVNI) {
DEBUG(dbgs() << ": not live\n");
return End;
}
DEBUG(dbgs() << ": valno " << ParentVNI->id);
VNInfo *VNI = defFromParent(OpenIdx, ParentVNI, Last, MBB,
- LIS.getLastSplitPoint(Edit.getParent(), &MBB));
+ LIS.getLastSplitPoint(Edit->getParent(), &MBB));
RegAssign.insert(VNI->def, End, OpenIdx);
DEBUG(dump());
return VNI->def;
// The interval must be live beyond the instruction at Idx.
Idx = Idx.getBoundaryIndex();
- VNInfo *ParentVNI = Edit.getParent().getVNInfoAt(Idx);
+ VNInfo *ParentVNI = Edit->getParent().getVNInfoAt(Idx);
if (!ParentVNI) {
DEBUG(dbgs() << ": not live\n");
return Idx.getNextSlot();
// The interval must be live into the instruction at Idx.
Idx = Idx.getBoundaryIndex();
- VNInfo *ParentVNI = Edit.getParent().getVNInfoAt(Idx);
+ VNInfo *ParentVNI = Edit->getParent().getVNInfoAt(Idx);
if (!ParentVNI) {
DEBUG(dbgs() << ": not live\n");
return Idx.getNextSlot();
SlotIndex Start = LIS.getMBBStartIdx(&MBB);
DEBUG(dbgs() << " leaveIntvAtTop BB#" << MBB.getNumber() << ", " << Start);
- VNInfo *ParentVNI = Edit.getParent().getVNInfoAt(Start);
+ VNInfo *ParentVNI = Edit->getParent().getVNInfoAt(Start);
if (!ParentVNI) {
DEBUG(dbgs() << ": not live\n");
return Start;
void SplitEditor::overlapIntv(SlotIndex Start, SlotIndex End) {
assert(OpenIdx && "openIntv not called before overlapIntv");
- assert(Edit.getParent().getVNInfoAt(Start) ==
- Edit.getParent().getVNInfoAt(End.getPrevSlot()) &&
+ const VNInfo *ParentVNI = Edit->getParent().getVNInfoAt(Start);
+ assert(ParentVNI == 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 extendRange().
+ if (ParentVNI)
+ markComplexMapped(0, ParentVNI);
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(OpenIdx && "openIntv not called before closeIntv");
- OpenIdx = 0;
+/// transferValues - Transfer all possible values to the new live ranges.
+/// Values that were rematerialized are left alone, they need extendRange().
+bool SplitEditor::transferValues() {
+ bool Skipped = false;
+ LiveInBlocks.clear();
+ RegAssignMap::const_iterator AssignI = RegAssign.begin();
+ for (LiveInterval::const_iterator ParentI = Edit->getParent().begin(),
+ ParentE = Edit->getParent().end(); ParentI != ParentE; ++ParentI) {
+ DEBUG(dbgs() << " blit " << *ParentI << ':');
+ VNInfo *ParentVNI = ParentI->valno;
+ // RegAssign has holes where RegIdx 0 should be used.
+ SlotIndex Start = ParentI->start;
+ AssignI.advanceTo(Start);
+ do {
+ unsigned RegIdx;
+ SlotIndex End = ParentI->end;
+ if (!AssignI.valid()) {
+ RegIdx = 0;
+ } else if (AssignI.start() <= Start) {
+ RegIdx = AssignI.value();
+ if (AssignI.stop() < End) {
+ End = AssignI.stop();
+ ++AssignI;
+ }
+ } else {
+ RegIdx = 0;
+ End = std::min(End, AssignI.start());
+ }
+
+ // The interval [Start;End) is continuously mapped to RegIdx, ParentVNI.
+ DEBUG(dbgs() << " [" << Start << ';' << End << ")=" << RegIdx);
+ LiveInterval *LI = Edit->get(RegIdx);
+
+ // Check for a simply defined value that can be blitted directly.
+ if (VNInfo *VNI = Values.lookup(std::make_pair(RegIdx, ParentVNI->id))) {
+ DEBUG(dbgs() << ':' << VNI->id);
+ LI->addRange(LiveRange(Start, End, VNI));
+ Start = End;
+ continue;
+ }
+
+ // Skip rematerialized values, we need to use extendRange() and
+ // extendPHIKillRanges() to completely recompute the live ranges.
+ if (Edit->didRematerialize(ParentVNI)) {
+ DEBUG(dbgs() << "(remat)");
+ Skipped = true;
+ Start = End;
+ continue;
+ }
+
+ // Initialize the live-out cache the first time it is needed.
+ if (LiveOutSeen.empty()) {
+ unsigned N = VRM.getMachineFunction().getNumBlockIDs();
+ LiveOutSeen.resize(N);
+ LiveOutCache.resize(N);
+ }
+
+ // This value has multiple defs in RegIdx, but it wasn't rematerialized,
+ // so the live range is accurate. Add live-in blocks in [Start;End) to the
+ // LiveInBlocks.
+ MachineFunction::iterator MBB = LIS.getMBBFromIndex(Start);
+ SlotIndex BlockStart, BlockEnd;
+ tie(BlockStart, BlockEnd) = LIS.getSlotIndexes()->getMBBRange(MBB);
+
+ // The first block may be live-in, or it may have its own def.
+ if (Start != BlockStart) {
+ VNInfo *VNI = LI->extendInBlock(BlockStart,
+ std::min(BlockEnd, End).getPrevSlot());
+ assert(VNI && "Missing def for complex mapped value");
+ DEBUG(dbgs() << ':' << VNI->id << "*BB#" << MBB->getNumber());
+ // MBB has its own def. Is it also live-out?
+ if (BlockEnd <= End) {
+ LiveOutSeen.set(MBB->getNumber());
+ LiveOutCache[MBB] = LiveOutPair(VNI, MDT[MBB]);
+ }
+ // Skip to the next block for live-in.
+ ++MBB;
+ BlockStart = BlockEnd;
+ }
+
+ // Handle the live-in blocks covered by [Start;End).
+ assert(Start <= BlockStart && "Expected live-in block");
+ while (BlockStart < End) {
+ DEBUG(dbgs() << ">BB#" << MBB->getNumber());
+ BlockEnd = LIS.getMBBEndIdx(MBB);
+ if (BlockStart == ParentVNI->def) {
+ // This block has the def of a parent PHI, so it isn't live-in.
+ assert(ParentVNI->isPHIDef() && "Non-phi defined at block start?");
+ VNInfo *VNI = LI->extendInBlock(BlockStart,
+ std::min(BlockEnd, End).getPrevSlot());
+ assert(VNI && "Missing def for complex mapped parent PHI");
+ if (End >= BlockEnd) {
+ // Live-out as well.
+ LiveOutSeen.set(MBB->getNumber());
+ LiveOutCache[MBB] = LiveOutPair(VNI, MDT[MBB]);
+ }
+ } else {
+ // This block needs a live-in value.
+ LiveInBlocks.push_back(MDT[MBB]);
+ // The last block covered may not be live-out.
+ if (End < BlockEnd)
+ LiveInBlocks.back().Kill = End;
+ else {
+ // Live-out, but we need updateSSA to tell us the value.
+ LiveOutSeen.set(MBB->getNumber());
+ LiveOutCache[MBB] = LiveOutPair((VNInfo*)0,
+ (MachineDomTreeNode*)0);
+ }
+ }
+ BlockStart = BlockEnd;
+ ++MBB;
+ }
+ Start = End;
+ } while (Start != ParentI->end);
+ DEBUG(dbgs() << '\n');
+ }
+
+ if (!LiveInBlocks.empty())
+ updateSSA();
+
+ return Skipped;
}
-/// rewriteAssigned - Rewrite all uses of Edit.getReg().
-void SplitEditor::rewriteAssigned() {
- for (MachineRegisterInfo::reg_iterator RI = MRI.reg_begin(Edit.getReg()),
+void SplitEditor::extendPHIKillRanges() {
+ // 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);
+ MachineBasicBlock *MBB = LIS.getMBBFromIndex(PHIVNI->def);
+ for (MachineBasicBlock::pred_iterator PI = MBB->pred_begin(),
+ PE = MBB->pred_end(); PI != PE; ++PI) {
+ SlotIndex End = LIS.getMBBEndIdx(*PI).getPrevSlot();
+ // The predecessor may not have a live-out value. That is OK, like an
+ // undef PHI operand.
+ if (Edit->getParent().liveAt(End)) {
+ assert(RegAssign.lookup(End) == RegIdx &&
+ "Different register assignment in phi predecessor");
+ extendRange(RegIdx, End);
+ }
+ }
+ }
+}
+
+/// rewriteAssigned - Rewrite all uses of Edit->getReg().
+void SplitEditor::rewriteAssigned(bool ExtendRanges) {
+ for (MachineRegisterInfo::reg_iterator RI = MRI.reg_begin(Edit->getReg()),
RE = MRI.reg_end(); RI != RE;) {
MachineOperand &MO = RI.getOperand();
MachineInstr *MI = MO.getParent();
// <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);
+ MO.setReg(Edit->get(0)->reg);
continue;
}
SlotIndex Idx = LIS.getInstructionIndex(MI);
- Idx = MO.isUse() ? Idx.getUseIndex() : Idx.getDefIndex();
+ if (MO.isDef())
+ Idx = MO.isEarlyClobber() ? Idx.getUseIndex() : Idx.getDefIndex();
// Rewrite to the mapped register at Idx.
unsigned RegIdx = RegAssign.lookup(Idx);
- MO.setReg(Edit.get(RegIdx)->reg);
+ MO.setReg(Edit->get(RegIdx)->reg);
DEBUG(dbgs() << " rewr BB#" << MI->getParent()->getNumber() << '\t'
<< Idx << ':' << RegIdx << '\t' << *MI);
- // Extend liveness to Idx.
+ // Extend liveness to Idx if the instruction reads reg.
+ if (!ExtendRanges)
+ continue;
+
+ // Skip instructions that don't read Reg.
+ if (MO.isDef()) {
+ if (!MO.getSubReg() && !MO.isEarlyClobber())
+ continue;
+ // We may wan't to extend a live range for a partial redef, or for a use
+ // tied to an early clobber.
+ Idx = Idx.getPrevSlot();
+ if (!Edit->getParent().liveAt(Idx))
+ continue;
+ } else
+ Idx = Idx.getUseIndex();
+
extendRange(RegIdx, Idx);
}
}
-/// 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::deleteRematVictims() {
+ SmallVector<MachineInstr*, 8> Dead;
+ for (LiveRangeEdit::iterator I = Edit->begin(), E = Edit->end(); I != E; ++I){
+ LiveInterval *LI = *I;
+ for (LiveInterval::const_iterator LII = LI->begin(), LIE = LI->end();
+ LII != LIE; ++LII) {
+ // Dead defs end at the store slot.
+ if (LII->end != LII->valno->def.getNextSlot())
+ continue;
+ MachineInstr *MI = LIS.getInstructionFromIndex(LII->valno->def);
+ assert(MI && "Missing instruction for dead def");
+ MI->addRegisterDead(LI->reg, &TRI);
+
+ if (!MI->allDefsAreDead())
+ continue;
+
+ DEBUG(dbgs() << "All defs dead: " << *MI);
+ Dead.push_back(MI);
+ }
}
+
+ if (Dead.empty())
+ return;
+
+ Edit->eliminateDeadDefs(Dead, LIS, VRM, TII);
}
-void SplitEditor::finish() {
- assert(OpenIdx == 0 && "Previous LI not closed before rewrite");
+void SplitEditor::finish(SmallVectorImpl<unsigned> *LRMap) {
+ ++NumFinished;
// At this point, the live intervals in Edit contain VNInfos corresponding to
// the inserted copies.
// 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) {
+ 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;
unsigned RegIdx = RegAssign.lookup(ParentVNI->def);
- // Mark all values as complex to force liveness computation.
- // This should really only be necessary for remat victims, but we are lazy.
- markComplexMapped(RegIdx, ParentVNI);
- defValue(RegIdx, ParentVNI, ParentVNI->def);
+ VNInfo *VNI = defValue(RegIdx, ParentVNI, ParentVNI->def);
+ VNI->setIsPHIDef(ParentVNI->isPHIDef());
+ VNI->setCopy(ParentVNI->getCopy());
+
+ // Mark rematted values as complex everywhere to force liveness computation.
+ // The new live ranges may be truncated.
+ if (Edit->didRematerialize(ParentVNI))
+ for (unsigned i = 0, e = Edit->size(); i != e; ++i)
+ markComplexMapped(i, ParentVNI);
}
#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)
+ 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 extendRange 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);
- 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 (Edit.getParent().liveAt(End)) {
- DEBUG(dbgs() << " has parent live out\n");
- assert(RegAssign.lookup(End) == RegIdx &&
- "Different register assignment in phi predecessor");
- extendRange(RegIdx, End);
- } else
- DEBUG(dbgs() << " is not live-out\n");
- }
- DEBUG(dbgs() << " " << *Edit.get(RegIdx) << '\n');
- }
+ // Transfer the simply mapped values, check if any are skipped.
+ bool Skipped = transferValues();
+ if (Skipped)
+ extendPHIKillRanges();
+ else
+ ++NumSimple;
- // Rewrite instructions.
- rewriteAssigned();
+ // Rewrite virtual registers, possibly extending ranges.
+ rewriteAssigned(Skipped);
- // FIXME: Delete defs that were rematted everywhere.
+ // Delete defs that were rematted everywhere.
+ if (Skipped)
+ deleteRematVictims();
// Get rid of unused values and set phi-kill flags.
- for (LiveRangeEdit::iterator I = Edit.begin(), E = Edit.end(); I != E; ++I)
+ for (LiveRangeEdit::iterator I = Edit->begin(), E = Edit->end(); I != E; ++I)
(*I)->RenumberValues(LIS);
+ // Provide a reverse mapping from original indices to Edit ranges.
+ if (LRMap) {
+ LRMap->clear();
+ for (unsigned i = 0, e = Edit->size(); i != e; ++i)
+ LRMap->push_back(i);
+ }
+
// Now check if any registers were separated into multiple components.
ConnectedVNInfoEqClasses ConEQ(LIS);
- for (unsigned i = 0, e = Edit.size(); i != e; ++i) {
+ 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);
+ 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]);
+ for (unsigned j = 1; j != NumComp; ++j)
+ dups.push_back(&Edit->create(LIS, VRM));
+ ConEQ.Distribute(&dups[0], MRI);
+ // The new intervals all map back to i.
+ if (LRMap)
+ LRMap->resize(Edit->size(), i);
}
// 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');
- }
+ Edit->calculateRegClassAndHint(VRM.getMachineFunction(), LIS, SA.Loops);
+
+ assert(!LRMap || LRMap->size() == Edit->size());
}
/// 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)
+ if (UseBlocks.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;
- unsigned Instrs = UsingBlocks.lookup(BI.MBB);
- if (Instrs <= 1)
- continue;
- if (Instrs == 2 && BI.LiveIn && BI.LiveOut && !BI.LiveThrough)
+ for (unsigned i = 0, e = UseBlocks.size(); i != e; ++i) {
+ const BlockInfo &BI = UseBlocks[i];
+ if (BI.FirstUse == BI.LastUse)
continue;
Blocks.insert(BI.MBB);
}
return !Blocks.empty();
}
+void SplitEditor::splitSingleBlock(const SplitAnalysis::BlockInfo &BI) {
+ openIntv();
+ SlotIndex LastSplitPoint = SA.getLastSplitPoint(BI.MBB->getNumber());
+ SlotIndex SegStart = enterIntvBefore(std::min(BI.FirstUse,
+ LastSplitPoint));
+ if (!BI.LiveOut || BI.LastUse < LastSplitPoint) {
+ useIntv(SegStart, leaveIntvAfter(BI.LastUse));
+ } else {
+ // The last use is after the last valid split point.
+ SlotIndex SegStop = leaveIntvBefore(LastSplitPoint);
+ useIntv(SegStart, SegStop);
+ overlapIntv(SegStop, BI.LastUse);
+ }
+}
+
/// 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");
-
- 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();
- SlotIndex SegStart = enterIntvBefore(BI.FirstUse);
- if (!BI.LiveOut || BI.LastUse < BI.LastSplitPoint) {
- useIntv(SegStart, leaveIntvAfter(BI.LastUse));
- } else {
- // The last use is after the last valid split point.
- SlotIndex SegStop = leaveIntvBefore(BI.LastSplitPoint);
- useIntv(SegStart, SegStop);
- overlapIntv(SegStop, BI.LastUse);
- }
- closeIntv();
+ ArrayRef<SplitAnalysis::BlockInfo> UseBlocks = SA.getUseBlocks();
+ for (unsigned i = 0; i != UseBlocks.size(); ++i) {
+ const SplitAnalysis::BlockInfo &BI = UseBlocks[i];
+ if (Blocks.count(BI.MBB))
+ splitSingleBlock(BI);
}
finish();
}
projects / oota-llvm.git / blobdiff