LiveIntervalAnalysis: Compute subregister ranges.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223878 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Matthias Braun
2014-12-10 01:12:12 +00:00
parent 01ddf04b63
commit c66fa840bf
2 changed files with 260 additions and 102 deletions

View File

@ -29,14 +29,75 @@ void LiveRangeCalc::reset(const MachineFunction *mf,
DomTree = MDT; DomTree = MDT;
Alloc = VNIA; Alloc = VNIA;
unsigned N = MF->getNumBlockIDs(); MainLiveOutData.reset(MF->getNumBlockIDs());
Seen.clear();
Seen.resize(N);
LiveOut.resize(N);
LiveIn.clear(); LiveIn.clear();
} }
static SlotIndex getDefIndex(const SlotIndexes &Indexes, const MachineInstr &MI,
bool EarlyClobber) {
// PHI defs begin at the basic block start index.
if (MI.isPHI())
return Indexes.getMBBStartIdx(MI.getParent());
// Instructions are either normal 'r', or early clobber 'e'.
return Indexes.getInstructionIndex(&MI).getRegSlot(EarlyClobber);
}
void LiveRangeCalc::createDeadDefs(LiveInterval &LI) {
assert(MRI && Indexes && "call reset() first");
// Visit all def operands. If the same instruction has multiple defs of Reg,
// LR.createDeadDef() will deduplicate.
const TargetRegisterInfo &TRI = *MRI->getTargetRegisterInfo();
unsigned Reg = LI.reg;
for (const MachineOperand &MO : MRI->def_operands(Reg)) {
const MachineInstr *MI = MO.getParent();
SlotIndex Idx = getDefIndex(*Indexes, *MI, MO.isEarlyClobber());
unsigned SubReg = MO.getSubReg();
if (SubReg != 0 || LI.hasSubRanges()) {
unsigned Mask = SubReg != 0 ? TRI.getSubRegIndexLaneMask(SubReg)
: MRI->getMaxLaneMaskForVReg(Reg);
// If this is the first time we see a subregister def, initialize
// subranges by creating a copy of the main range.
if (!LI.hasSubRanges() && !LI.empty()) {
unsigned ClassMask = MRI->getMaxLaneMaskForVReg(Reg);
LI.createSubRangeFrom(*Alloc, ClassMask, LI);
}
for (LiveInterval::subrange_iterator S = LI.subrange_begin(),
SE = LI.subrange_end(); S != SE; ++S) {
// A Mask for subregs common to the existing subrange and current def.
unsigned Common = S->LaneMask & Mask;
if (Common == 0)
continue;
// A Mask for subregs covered by the subrange but not the current def.
unsigned LRest = S->LaneMask & ~Mask;
LiveInterval::SubRange *CommonRange;
if (LRest != 0) {
// Split current subrange into Common and LRest ranges.
S->LaneMask = LRest;
CommonRange = LI.createSubRangeFrom(*Alloc, Common, *S);
} else {
assert(Common == S->LaneMask);
CommonRange = &*S;
}
CommonRange->createDeadDef(Idx, *Alloc);
Mask &= ~Common;
}
if (Mask != 0) {
LiveInterval::SubRange *SubRange = LI.createSubRange(*Alloc, Mask);
SubRange->createDeadDef(Idx, *Alloc);
}
}
// Create the def in LR. This may find an existing def.
LI.createDeadDef(Idx, *Alloc);
}
}
void LiveRangeCalc::createDeadDefs(LiveRange &LR, unsigned Reg) { void LiveRangeCalc::createDeadDefs(LiveRange &LR, unsigned Reg) {
assert(MRI && Indexes && "call reset() first"); assert(MRI && Indexes && "call reset() first");
@ -44,22 +105,38 @@ void LiveRangeCalc::createDeadDefs(LiveRange &LR, unsigned Reg) {
// LR.createDeadDef() will deduplicate. // LR.createDeadDef() will deduplicate.
for (MachineOperand &MO : MRI->def_operands(Reg)) { for (MachineOperand &MO : MRI->def_operands(Reg)) {
const MachineInstr *MI = MO.getParent(); const MachineInstr *MI = MO.getParent();
// Find the corresponding slot index. SlotIndex Idx = getDefIndex(*Indexes, *MI, MO.isEarlyClobber());
SlotIndex Idx;
if (MI->isPHI())
// PHI defs begin at the basic block start index.
Idx = Indexes->getMBBStartIdx(MI->getParent());
else
// Instructions are either normal 'r', or early clobber 'e'.
Idx = Indexes->getInstructionIndex(MI)
.getRegSlot(MO.isEarlyClobber());
// Create the def in LR. This may find an existing def. // Create the def in LR. This may find an existing def.
LR.createDeadDef(Idx, *Alloc); LR.createDeadDef(Idx, *Alloc);
} }
} }
static SlotIndex getUseIndex(const SlotIndexes &Indexes,
const MachineOperand &MO) {
const MachineInstr *MI = MO.getParent();
unsigned OpNo = (&MO - &MI->getOperand(0));
if (MI->isPHI()) {
assert(!MO.isDef() && "Cannot handle PHI def of partial register.");
// The actual place where a phi operand is used is the end of the pred MBB.
// PHI operands are paired: (Reg, PredMBB).
return Indexes.getMBBEndIdx(MI->getOperand(OpNo+1).getMBB());
}
// Check for early-clobber redefs.
bool isEarlyClobber = false;
unsigned DefIdx;
if (MO.isDef()) {
isEarlyClobber = MO.isEarlyClobber();
} else if (MI->isRegTiedToDefOperand(OpNo, &DefIdx)) {
// FIXME: This would be a lot easier if tied early-clobber uses also
// had an early-clobber flag.
isEarlyClobber = MI->getOperand(DefIdx).isEarlyClobber();
}
return Indexes.getInstructionIndex(MI).getRegSlot(isEarlyClobber);
}
void LiveRangeCalc::extendToUses(LiveRange &LR, unsigned Reg) { void LiveRangeCalc::extendToUses(LiveRange &LR, unsigned Reg) {
assert(MRI && Indexes && "call reset() first"); assert(MRI && Indexes && "call reset() first");
@ -73,38 +150,86 @@ void LiveRangeCalc::extendToUses(LiveRange &LR, unsigned Reg) {
continue; continue;
// MI is reading Reg. We may have visited MI before if it happens to be // MI is reading Reg. We may have visited MI before if it happens to be
// reading Reg multiple times. That is OK, extend() is idempotent. // reading Reg multiple times. That is OK, extend() is idempotent.
const MachineInstr *MI = MO.getParent(); SlotIndex Idx = getUseIndex(*Indexes, MO);
unsigned OpNo = (&MO - &MI->getOperand(0)); extend(LR, Idx, Reg, MainLiveOutData);
}
}
// Find the SlotIndex being read.
SlotIndex Idx; void LiveRangeCalc::extendToUses(LiveInterval &LI) {
if (MI->isPHI()) { assert(MRI && Indexes && "call reset() first");
assert(!MO.isDef() && "Cannot handle PHI def of partial register.");
// PHI operands are paired: (Reg, PredMBB). const TargetRegisterInfo &TRI = *MRI->getTargetRegisterInfo();
// Extend the live range to be live-out from PredMBB. SmallVector<LiveOutData,2> LiveOuts;
Idx = Indexes->getMBBEndIdx(MI->getOperand(OpNo+1).getMBB()); unsigned NumSubRanges = 0;
for (LiveInterval::subrange_iterator S = LI.subrange_begin(),
SE = LI.subrange_end(); S != SE; ++S, ++NumSubRanges) {
LiveOuts.push_back(LiveOutData());
LiveOuts.back().reset(MF->getNumBlockIDs());
}
// Visit all operands that read Reg. This may include partial defs.
unsigned Reg = LI.reg;
for (MachineOperand &MO : MRI->reg_nodbg_operands(Reg)) {
// Clear all kill flags. They will be reinserted after register allocation
// by LiveIntervalAnalysis::addKillFlags().
if (MO.isUse())
MO.setIsKill(false);
if (!MO.readsReg())
continue;
SlotIndex Idx = getUseIndex(*Indexes, MO);
unsigned SubReg = MO.getSubReg();
if (MO.isUse() && (LI.hasSubRanges() || SubReg != 0)) {
unsigned Mask = SubReg != 0
? TRI.getSubRegIndexLaneMask(SubReg)
: Mask = MRI->getMaxLaneMaskForVReg(Reg);
// If this is the first time we see a subregister def/use. Initialize
// subranges by creating a copy of the main range.
if (!LI.hasSubRanges()) {
unsigned ClassMask = MRI->getMaxLaneMaskForVReg(Reg);
LI.createSubRangeFrom(*Alloc, ClassMask, LI);
LiveOuts.insert(LiveOuts.begin(), LiveOutData());
LiveOuts.front().reset(MF->getNumBlockIDs());
++NumSubRanges;
}
unsigned SubRangeIdx = 0;
for (LiveInterval::subrange_iterator S = LI.subrange_begin(),
SE = LI.subrange_end(); S != SE; ++S, ++SubRangeIdx) {
// A Mask for subregs common to the existing subrange and current def.
unsigned Common = S->LaneMask & Mask;
if (Common == 0)
continue;
// A Mask for subregs covered by the subrange but not the current def.
unsigned LRest = S->LaneMask & ~Mask;
LiveInterval::SubRange *CommonRange;
unsigned CommonRangeIdx;
if (LRest != 0) {
// Split current subrange into Common and LRest ranges.
S->LaneMask = LRest;
CommonRange = LI.createSubRangeFrom(*Alloc, Common, *S);
CommonRangeIdx = 0;
LiveOuts.insert(LiveOuts.begin(), LiveOutData());
LiveOuts.front().reset(MF->getNumBlockIDs());
++NumSubRanges;
++SubRangeIdx;
} else { } else {
// This is a normal instruction. // The subrange and current def lanemasks match completely.
Idx = Indexes->getInstructionIndex(MI).getRegSlot(); assert(Common == S->LaneMask);
// Check for early-clobber redefs. CommonRange = &*S;
unsigned DefIdx; CommonRangeIdx = SubRangeIdx;
if (MO.isDef()) {
if (MO.isEarlyClobber())
Idx = Idx.getRegSlot(true);
} else if (MI->isRegTiedToDefOperand(OpNo, &DefIdx)) {
// FIXME: This would be a lot easier if tied early-clobber uses also
// had an early-clobber flag.
if (MI->getOperand(DefIdx).isEarlyClobber())
Idx = Idx.getRegSlot(true);
} }
extend(*CommonRange, Idx, Reg, LiveOuts[CommonRangeIdx]);
Mask &= ~Common;
} }
extend(LR, Idx, Reg); assert(SubRangeIdx == NumSubRanges);
}
extend(LI, Idx, Reg, MainLiveOutData);
} }
} }
// Transfer information from the LiveIn vector to the live ranges. void LiveRangeCalc::updateFromLiveIns(LiveOutData &LiveOuts) {
void LiveRangeCalc::updateLiveIns() {
LiveRangeUpdater Updater; LiveRangeUpdater Updater;
for (SmallVectorImpl<LiveInBlock>::iterator I = LiveIn.begin(), for (SmallVectorImpl<LiveInBlock>::iterator I = LiveIn.begin(),
E = LiveIn.end(); I != E; ++I) { E = LiveIn.end(); I != E; ++I) {
@ -121,8 +246,8 @@ void LiveRangeCalc::updateLiveIns() {
else { else {
// The value is live-through, update LiveOut as well. // The value is live-through, update LiveOut as well.
// Defer the Domtree lookup until it is needed. // Defer the Domtree lookup until it is needed.
assert(Seen.test(MBB->getNumber())); assert(LiveOuts.Seen.test(MBB->getNumber()));
LiveOut[MBB] = LiveOutPair(I->Value, (MachineDomTreeNode *)nullptr); LiveOuts.Map[MBB] = LiveOutPair(I->Value, nullptr);
} }
Updater.setDest(&I->LR); Updater.setDest(&I->LR);
Updater.add(Start, End, I->Value); Updater.add(Start, End, I->Value);
@ -131,7 +256,8 @@ void LiveRangeCalc::updateLiveIns() {
} }
void LiveRangeCalc::extend(LiveRange &LR, SlotIndex Kill, unsigned PhysReg) { void LiveRangeCalc::extend(LiveRange &LR, SlotIndex Kill, unsigned PhysReg,
LiveOutData &LiveOuts) {
assert(Kill.isValid() && "Invalid SlotIndex"); assert(Kill.isValid() && "Invalid SlotIndex");
assert(Indexes && "Missing SlotIndexes"); assert(Indexes && "Missing SlotIndexes");
assert(DomTree && "Missing dominator tree"); assert(DomTree && "Missing dominator tree");
@ -147,27 +273,28 @@ void LiveRangeCalc::extend(LiveRange &LR, SlotIndex Kill, unsigned PhysReg) {
// multiple values, and we may need to create even more phi-defs to preserve // multiple values, and we may need to create even more phi-defs to preserve
// VNInfo SSA form. Perform a search for all predecessor blocks where we // VNInfo SSA form. Perform a search for all predecessor blocks where we
// know the dominating VNInfo. // know the dominating VNInfo.
if (findReachingDefs(LR, *KillMBB, Kill, PhysReg)) if (findReachingDefs(LR, *KillMBB, Kill, PhysReg, LiveOuts))
return; return;
// When there were multiple different values, we may need new PHIs. // When there were multiple different values, we may need new PHIs.
calculateValues(); calculateValues(LiveOuts);
} }
// This function is called by a client after using the low-level API to add // This function is called by a client after using the low-level API to add
// live-out and live-in blocks. The unique value optimization is not // live-out and live-in blocks. The unique value optimization is not
// available, SplitEditor::transferValues handles that case directly anyway. // available, SplitEditor::transferValues handles that case directly anyway.
void LiveRangeCalc::calculateValues() { void LiveRangeCalc::calculateValues(LiveOutData &LiveOuts) {
assert(Indexes && "Missing SlotIndexes"); assert(Indexes && "Missing SlotIndexes");
assert(DomTree && "Missing dominator tree"); assert(DomTree && "Missing dominator tree");
updateSSA(); updateSSA(LiveOuts);
updateLiveIns(); updateFromLiveIns(LiveOuts);
} }
bool LiveRangeCalc::findReachingDefs(LiveRange &LR, MachineBasicBlock &KillMBB, bool LiveRangeCalc::findReachingDefs(LiveRange &LR, MachineBasicBlock &KillMBB,
SlotIndex Kill, unsigned PhysReg) { SlotIndex Kill, unsigned PhysReg,
LiveOutData &LiveOuts) {
unsigned KillMBBNum = KillMBB.getNumber(); unsigned KillMBBNum = KillMBB.getNumber();
// Block numbers where LR should be live-in. // Block numbers where LR should be live-in.
@ -201,8 +328,8 @@ bool LiveRangeCalc::findReachingDefs(LiveRange &LR, MachineBasicBlock &KillMBB,
MachineBasicBlock *Pred = *PI; MachineBasicBlock *Pred = *PI;
// Is this a known live-out block? // Is this a known live-out block?
if (Seen.test(Pred->getNumber())) { if (LiveOuts.Seen.test(Pred->getNumber())) {
if (VNInfo *VNI = LiveOut[Pred].first) { if (VNInfo *VNI = LiveOuts.Map[Pred].first) {
if (TheVNI && TheVNI != VNI) if (TheVNI && TheVNI != VNI)
UniqueVNI = false; UniqueVNI = false;
TheVNI = VNI; TheVNI = VNI;
@ -216,7 +343,7 @@ bool LiveRangeCalc::findReachingDefs(LiveRange &LR, MachineBasicBlock &KillMBB,
// First time we see Pred. Try to determine the live-out value, but set // First time we see Pred. Try to determine the live-out value, but set
// it as null if Pred is live-through with an unknown value. // it as null if Pred is live-through with an unknown value.
VNInfo *VNI = LR.extendInBlock(Start, End); VNInfo *VNI = LR.extendInBlock(Start, End);
setLiveOutValue(Pred, VNI); LiveOuts.setLiveOutValue(Pred, VNI);
if (VNI) { if (VNI) {
if (TheVNI && TheVNI != VNI) if (TheVNI && TheVNI != VNI)
UniqueVNI = false; UniqueVNI = false;
@ -251,7 +378,7 @@ bool LiveRangeCalc::findReachingDefs(LiveRange &LR, MachineBasicBlock &KillMBB,
if (*I == KillMBBNum && Kill.isValid()) if (*I == KillMBBNum && Kill.isValid())
End = Kill; End = Kill;
else else
LiveOut[MF->getBlockNumbered(*I)] = LiveOuts.Map[MF->getBlockNumbered(*I)] =
LiveOutPair(TheVNI, nullptr); LiveOutPair(TheVNI, nullptr);
Updater.add(Start, End, TheVNI); Updater.add(Start, End, TheVNI);
} }
@ -275,7 +402,7 @@ bool LiveRangeCalc::findReachingDefs(LiveRange &LR, MachineBasicBlock &KillMBB,
// This is essentially the same iterative algorithm that SSAUpdater uses, // 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. // except we already have a dominator tree, so we don't have to recompute it.
void LiveRangeCalc::updateSSA() { void LiveRangeCalc::updateSSA(LiveOutData &LiveOuts) {
assert(Indexes && "Missing SlotIndexes"); assert(Indexes && "Missing SlotIndexes");
assert(DomTree && "Missing dominator tree"); assert(DomTree && "Missing dominator tree");
@ -297,22 +424,23 @@ void LiveRangeCalc::updateSSA() {
// We need a live-in value to a block with no immediate dominator? // We need a live-in value to a block with no immediate dominator?
// This is probably an unreachable block that has survived somehow. // This is probably an unreachable block that has survived somehow.
bool needPHI = !IDom || !Seen.test(IDom->getBlock()->getNumber()); bool needPHI = !IDom
|| !LiveOuts.Seen.test(IDom->getBlock()->getNumber());
// IDom dominates all of our predecessors, but it may not be their // 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 // 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. // properly dominated by IDom. If so, we need a phi-def here.
if (!needPHI) { if (!needPHI) {
IDomValue = LiveOut[IDom->getBlock()]; IDomValue = LiveOuts.Map[IDom->getBlock()];
// Cache the DomTree node that defined the value. // Cache the DomTree node that defined the value.
if (IDomValue.first && !IDomValue.second) if (IDomValue.first && !IDomValue.second)
LiveOut[IDom->getBlock()].second = IDomValue.second = LiveOuts.Map[IDom->getBlock()].second = IDomValue.second =
DomTree->getNode(Indexes->getMBBFromIndex(IDomValue.first->def)); DomTree->getNode(Indexes->getMBBFromIndex(IDomValue.first->def));
for (MachineBasicBlock::pred_iterator PI = MBB->pred_begin(), for (MachineBasicBlock::pred_iterator PI = MBB->pred_begin(),
PE = MBB->pred_end(); PI != PE; ++PI) { PE = MBB->pred_end(); PI != PE; ++PI) {
LiveOutPair &Value = LiveOut[*PI]; LiveOutPair &Value = LiveOuts.Map[*PI];
if (!Value.first || Value.first == IDomValue.first) if (!Value.first || Value.first == IDomValue.first)
continue; continue;
@ -334,7 +462,7 @@ void LiveRangeCalc::updateSSA() {
// The value may be live-through even if Kill is set, as can happen when // 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 // we are called from extendRange. In that case LiveOutSeen is true, and
// LiveOut indicates a foreign or missing value. // LiveOut indicates a foreign or missing value.
LiveOutPair &LOP = LiveOut[MBB]; LiveOutPair &LOP = LiveOuts.Map[MBB];
// Create a phi-def if required. // Create a phi-def if required.
if (needPHI) { if (needPHI) {
@ -348,7 +476,7 @@ void LiveRangeCalc::updateSSA() {
// This block is done, we know the final value. // This block is done, we know the final value.
I->DomNode = nullptr; I->DomNode = nullptr;
// Add liveness since updateLiveIns now skips this node. // Add liveness since updateFromLiveIns now skips this node.
if (I->Kill.isValid()) if (I->Kill.isValid())
LR.addSegment(LiveInterval::Segment(Start, I->Kill, VNI)); LR.addSegment(LiveInterval::Segment(Start, I->Kill, VNI));
else { else {

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@ -40,12 +40,6 @@ class LiveRangeCalc {
MachineDominatorTree *DomTree; MachineDominatorTree *DomTree;
VNInfo::Allocator *Alloc; VNInfo::Allocator *Alloc;
/// Seen - Bit vector of active entries in LiveOut, also used as a visited
/// set by findReachingDefs. One entry per basic block, indexed by block
/// number. This is kept as a separate bit vector because it can be cleared
/// quickly when switching live ranges.
BitVector Seen;
/// LiveOutPair - A value and the block that defined it. The domtree node is /// LiveOutPair - A value and the block that defined it. The domtree node is
/// redundant, it can be computed as: MDT[Indexes.getMBBFromIndex(VNI->def)]. /// redundant, it can be computed as: MDT[Indexes.getMBBFromIndex(VNI->def)].
typedef std::pair<VNInfo*, MachineDomTreeNode*> LiveOutPair; typedef std::pair<VNInfo*, MachineDomTreeNode*> LiveOutPair;
@ -53,6 +47,13 @@ class LiveRangeCalc {
/// LiveOutMap - Map basic blocks to the value leaving the block. /// LiveOutMap - Map basic blocks to the value leaving the block.
typedef IndexedMap<LiveOutPair, MBB2NumberFunctor> LiveOutMap; typedef IndexedMap<LiveOutPair, MBB2NumberFunctor> LiveOutMap;
struct LiveOutData {
/// Seen - Bit vector of active entries in LiveOut, also used as a visited
/// set by findReachingDefs. One entry per basic block, indexed by block
/// number. This is kept as a separate bit vector because it can be cleared
/// quickly when switching live ranges.
BitVector Seen;
/// LiveOut - Map each basic block where a live range is live out to the /// LiveOut - Map each basic block where a live range is live out to the
/// live-out value and its defining block. /// live-out value and its defining block.
/// ///
@ -70,7 +71,20 @@ class LiveRangeCalc {
/// ///
/// The map can be shared by multiple live ranges as long as no two are /// The map can be shared by multiple live ranges as long as no two are
/// live-out of the same block. /// live-out of the same block.
LiveOutMap LiveOut; LiveOutMap Map;
void reset(unsigned NumBlocks) {
Seen.clear();
Seen.resize(NumBlocks);
Map.resize(NumBlocks);
}
void setLiveOutValue(MachineBasicBlock *MBB, VNInfo *VNI) {
Seen.set(MBB->getNumber());
Map[MBB] = LiveOutPair(VNI, nullptr);
}
};
LiveOutData MainLiveOutData;
/// LiveInBlock - Information about a basic block where a live range is known /// LiveInBlock - Information about a basic block where a live range is known
/// to be live-in, but the value has not yet been determined. /// to be live-in, but the value has not yet been determined.
@ -112,17 +126,19 @@ class LiveRangeCalc {
/// ///
/// PhysReg, when set, is used to verify live-in lists on basic blocks. /// PhysReg, when set, is used to verify live-in lists on basic blocks.
bool findReachingDefs(LiveRange &LR, MachineBasicBlock &KillMBB, bool findReachingDefs(LiveRange &LR, MachineBasicBlock &KillMBB,
SlotIndex Kill, unsigned PhysReg); SlotIndex Kill, unsigned PhysReg,
LiveOutData &LiveOuts);
/// updateSSA - Compute the values that will be live in to all requested /// updateSSA - Compute the values that will be live in to all requested
/// blocks in LiveIn. Create PHI-def values as required to preserve SSA form. /// blocks in LiveIn. Create PHI-def values as required to preserve SSA form.
/// ///
/// Every live-in block must be jointly dominated by the added live-out /// Every live-in block must be jointly dominated by the added live-out
/// blocks. No values are read from the live ranges. /// blocks. No values are read from the live ranges.
void updateSSA(); void updateSSA(LiveOutData &LiveOuts);
/// Add liveness as specified in the LiveIn vector. /// Transfer information from the LiveIn vector to the live ranges and update
void updateLiveIns(); /// the given @p LiveOuts.
void updateFromLiveIns(LiveOutData &LiveOuts);
public: public:
LiveRangeCalc() : MF(nullptr), MRI(nullptr), Indexes(nullptr), LiveRangeCalc() : MF(nullptr), MRI(nullptr), Indexes(nullptr),
@ -160,17 +176,25 @@ public:
/// single existing value, Alloc may be null. /// single existing value, Alloc may be null.
/// ///
/// PhysReg, when set, is used to verify live-in lists on basic blocks. /// PhysReg, when set, is used to verify live-in lists on basic blocks.
void extend(LiveRange &LR, SlotIndex Kill, unsigned PhysReg = 0); void extend(LiveRange &LR, SlotIndex Kill, unsigned PhysReg,
LiveOutData &LiveOuts);
void extend(LiveRange &LR, SlotIndex Kill) {
extend(LR, Kill, 0, MainLiveOutData);
}
/// createDeadDefs - Create a dead def in LI for every def operand of Reg. /// createDeadDefs - Create a dead def in LI for every def operand of Reg.
/// Each instruction defining Reg gets a new VNInfo with a corresponding /// Each instruction defining Reg gets a new VNInfo with a corresponding
/// minimal live range. /// minimal live range.
void createDeadDefs(LiveRange &LR, unsigned Reg); void createDeadDefs(LiveRange &LR, unsigned Reg);
/// createDeadDefs - Create a dead def in LI for every def of LI->reg. /// Subregister aware version of createDeadDefs(LiveRange &LR, unsigned Reg).
void createDeadDefs(LiveInterval &LI) { /// If subregister liveness tracking is enabled new subranges are created as
createDeadDefs(LI, LI.reg); /// necessary when subregister defs are found. As with
} /// createDeadDefs(LiveRange &LR, unsigned Reg) new short live segments are
/// created for every def of LI.reg. The new segments start and end at the
/// defining instruction (hence the name "DeadDef").
void createDeadDefs(LiveInterval &LI);
/// extendToUses - Extend the live range of LI to reach all uses of Reg. /// extendToUses - Extend the live range of LI to reach all uses of Reg.
/// ///
@ -178,10 +202,13 @@ public:
/// inserted as needed to preserve SSA form. /// inserted as needed to preserve SSA form.
void extendToUses(LiveRange &LR, unsigned Reg); void extendToUses(LiveRange &LR, unsigned Reg);
/// extendToUses - Extend the live range of LI to reach all uses of LI->reg. /// Subregister aware version of extendToUses(LiveRange &LR, unsigned Reg).
void extendToUses(LiveInterval &LI) { /// If subregister liveness tracking is enabled new subranges are created
extendToUses(LI, LI.reg); /// as necessary when subregister uses are found. As with
} /// extendToUses(LiveRange &LR, unsigned Reg) the segments existing at the
/// defs are extend until they reach all uses. New value numbers are created
/// at CFG joins as necessary (SSA construction).
void extendToUses(LiveInterval &LI);
//===--------------------------------------------------------------------===// //===--------------------------------------------------------------------===//
// Low-level interface. // Low-level interface.
@ -203,8 +230,7 @@ public:
/// VNI may be null only if MBB is a live-through block also passed to /// VNI may be null only if MBB is a live-through block also passed to
/// addLiveInBlock(). /// addLiveInBlock().
void setLiveOutValue(MachineBasicBlock *MBB, VNInfo *VNI) { void setLiveOutValue(MachineBasicBlock *MBB, VNInfo *VNI) {
Seen.set(MBB->getNumber()); MainLiveOutData.setLiveOutValue(MBB, VNI);
LiveOut[MBB] = LiveOutPair(VNI, nullptr);
} }
/// addLiveInBlock - Add a block with an unknown live-in value. This /// addLiveInBlock - Add a block with an unknown live-in value. This
@ -229,7 +255,11 @@ public:
/// ///
/// Every predecessor of a live-in block must have been given a value with /// Every predecessor of a live-in block must have been given a value with
/// setLiveOutValue, the value may be null for live-trough blocks. /// setLiveOutValue, the value may be null for live-trough blocks.
void calculateValues(); void calculateValues(LiveOutData &LiveOuts);
void calculateValues() {
calculateValues(MainLiveOutData);
}
}; };
} // end namespace llvm } // end namespace llvm