1 //===-- LiveIntervalAnalysis.cpp - Live Interval Analysis -----------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file implements the LiveInterval analysis pass which is used
11 // by the Linear Scan Register allocator. This pass linearizes the
12 // basic blocks of the function in DFS order and uses the
13 // LiveVariables pass to conservatively compute live intervals for
14 // each virtual and physical register.
16 //===----------------------------------------------------------------------===//
18 #define DEBUG_TYPE "regalloc"
19 #include "llvm/CodeGen/LiveIntervalAnalysis.h"
20 #include "llvm/Value.h"
21 #include "llvm/Analysis/AliasAnalysis.h"
22 #include "llvm/CodeGen/LiveVariables.h"
23 #include "llvm/CodeGen/MachineDominators.h"
24 #include "llvm/CodeGen/MachineInstr.h"
25 #include "llvm/CodeGen/MachineRegisterInfo.h"
26 #include "llvm/CodeGen/Passes.h"
27 #include "llvm/Target/TargetRegisterInfo.h"
28 #include "llvm/Target/TargetInstrInfo.h"
29 #include "llvm/Target/TargetMachine.h"
30 #include "llvm/Support/CommandLine.h"
31 #include "llvm/Support/Debug.h"
32 #include "llvm/Support/ErrorHandling.h"
33 #include "llvm/Support/raw_ostream.h"
34 #include "llvm/ADT/DenseSet.h"
35 #include "llvm/ADT/STLExtras.h"
36 #include "LiveRangeCalc.h"
37 #include "VirtRegMap.h"
43 // Switch to the new experimental algorithm for computing live intervals.
45 NewLiveIntervals("new-live-intervals", cl::Hidden,
46 cl::desc("Use new algorithm forcomputing live intervals"));
48 char LiveIntervals::ID = 0;
49 char &llvm::LiveIntervalsID = LiveIntervals::ID;
50 INITIALIZE_PASS_BEGIN(LiveIntervals, "liveintervals",
51 "Live Interval Analysis", false, false)
52 INITIALIZE_AG_DEPENDENCY(AliasAnalysis)
53 INITIALIZE_PASS_DEPENDENCY(LiveVariables)
54 INITIALIZE_PASS_DEPENDENCY(MachineDominatorTree)
55 INITIALIZE_PASS_DEPENDENCY(SlotIndexes)
56 INITIALIZE_PASS_END(LiveIntervals, "liveintervals",
57 "Live Interval Analysis", false, false)
59 void LiveIntervals::getAnalysisUsage(AnalysisUsage &AU) const {
61 AU.addRequired<AliasAnalysis>();
62 AU.addPreserved<AliasAnalysis>();
63 AU.addRequired<LiveVariables>();
64 AU.addPreserved<LiveVariables>();
65 AU.addPreservedID(MachineLoopInfoID);
66 AU.addRequiredTransitiveID(MachineDominatorsID);
67 AU.addPreservedID(MachineDominatorsID);
68 AU.addPreserved<SlotIndexes>();
69 AU.addRequiredTransitive<SlotIndexes>();
70 MachineFunctionPass::getAnalysisUsage(AU);
73 LiveIntervals::LiveIntervals() : MachineFunctionPass(ID),
74 DomTree(0), LRCalc(0) {
75 initializeLiveIntervalsPass(*PassRegistry::getPassRegistry());
78 LiveIntervals::~LiveIntervals() {
82 void LiveIntervals::releaseMemory() {
83 // Free the live intervals themselves.
84 for (unsigned i = 0, e = VirtRegIntervals.size(); i != e; ++i)
85 delete VirtRegIntervals[TargetRegisterInfo::index2VirtReg(i)];
86 VirtRegIntervals.clear();
89 RegMaskBlocks.clear();
91 for (unsigned i = 0, e = RegUnitIntervals.size(); i != e; ++i)
92 delete RegUnitIntervals[i];
93 RegUnitIntervals.clear();
95 // Release VNInfo memory regions, VNInfo objects don't need to be dtor'd.
96 VNInfoAllocator.Reset();
99 /// runOnMachineFunction - Register allocate the whole function
101 bool LiveIntervals::runOnMachineFunction(MachineFunction &fn) {
103 MRI = &MF->getRegInfo();
104 TM = &fn.getTarget();
105 TRI = TM->getRegisterInfo();
106 TII = TM->getInstrInfo();
107 AA = &getAnalysis<AliasAnalysis>();
108 LV = &getAnalysis<LiveVariables>();
109 Indexes = &getAnalysis<SlotIndexes>();
110 DomTree = &getAnalysis<MachineDominatorTree>();
112 LRCalc = new LiveRangeCalc();
113 AllocatableRegs = TRI->getAllocatableSet(fn);
114 ReservedRegs = TRI->getReservedRegs(fn);
116 // Allocate space for all virtual registers.
117 VirtRegIntervals.resize(MRI->getNumVirtRegs());
119 if (NewLiveIntervals) {
120 // This is the new way of computing live intervals.
121 // It is independent of LiveVariables, and it can run at any time.
125 // This is the old way of computing live intervals.
126 // It depends on LiveVariables.
129 computeLiveInRegUnits();
135 /// print - Implement the dump method.
136 void LiveIntervals::print(raw_ostream &OS, const Module* ) const {
137 OS << "********** INTERVALS **********\n";
139 // Dump the regunits.
140 for (unsigned i = 0, e = RegUnitIntervals.size(); i != e; ++i)
141 if (LiveInterval *LI = RegUnitIntervals[i])
142 OS << PrintRegUnit(i, TRI) << " = " << *LI << '\n';
144 // Dump the virtregs.
145 for (unsigned i = 0, e = MRI->getNumVirtRegs(); i != e; ++i) {
146 unsigned Reg = TargetRegisterInfo::index2VirtReg(i);
147 if (hasInterval(Reg))
148 OS << PrintReg(Reg) << " = " << getInterval(Reg) << '\n';
154 void LiveIntervals::printInstrs(raw_ostream &OS) const {
155 OS << "********** MACHINEINSTRS **********\n";
156 MF->print(OS, Indexes);
159 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
160 void LiveIntervals::dumpInstrs() const {
166 bool MultipleDefsBySameMI(const MachineInstr &MI, unsigned MOIdx) {
167 unsigned Reg = MI.getOperand(MOIdx).getReg();
168 for (unsigned i = MOIdx+1, e = MI.getNumOperands(); i < e; ++i) {
169 const MachineOperand &MO = MI.getOperand(i);
172 if (MO.getReg() == Reg && MO.isDef()) {
173 assert(MI.getOperand(MOIdx).getSubReg() != MO.getSubReg() &&
174 MI.getOperand(MOIdx).getSubReg() &&
175 (MO.getSubReg() || MO.isImplicit()));
182 /// isPartialRedef - Return true if the specified def at the specific index is
183 /// partially re-defining the specified live interval. A common case of this is
184 /// a definition of the sub-register.
185 bool LiveIntervals::isPartialRedef(SlotIndex MIIdx, MachineOperand &MO,
186 LiveInterval &interval) {
187 if (!MO.getSubReg() || MO.isEarlyClobber())
190 SlotIndex RedefIndex = MIIdx.getRegSlot();
191 const LiveRange *OldLR =
192 interval.getLiveRangeContaining(RedefIndex.getRegSlot(true));
193 MachineInstr *DefMI = getInstructionFromIndex(OldLR->valno->def);
195 return DefMI->findRegisterDefOperandIdx(interval.reg) != -1;
200 void LiveIntervals::handleVirtualRegisterDef(MachineBasicBlock *mbb,
201 MachineBasicBlock::iterator mi,
205 LiveInterval &interval) {
206 DEBUG(dbgs() << "\t\tregister: " << PrintReg(interval.reg, TRI));
208 // Virtual registers may be defined multiple times (due to phi
209 // elimination and 2-addr elimination). Much of what we do only has to be
210 // done once for the vreg. We use an empty interval to detect the first
211 // time we see a vreg.
212 LiveVariables::VarInfo& vi = LV->getVarInfo(interval.reg);
213 if (interval.empty()) {
214 // Get the Idx of the defining instructions.
215 SlotIndex defIndex = MIIdx.getRegSlot(MO.isEarlyClobber());
217 // Make sure the first definition is not a partial redefinition.
218 assert(!MO.readsReg() && "First def cannot also read virtual register "
219 "missing <undef> flag?");
221 VNInfo *ValNo = interval.getNextValue(defIndex, VNInfoAllocator);
222 assert(ValNo->id == 0 && "First value in interval is not 0?");
224 // Loop over all of the blocks that the vreg is defined in. There are
225 // two cases we have to handle here. The most common case is a vreg
226 // whose lifetime is contained within a basic block. In this case there
227 // will be a single kill, in MBB, which comes after the definition.
228 if (vi.Kills.size() == 1 && vi.Kills[0]->getParent() == mbb) {
229 // FIXME: what about dead vars?
231 if (vi.Kills[0] != mi)
232 killIdx = getInstructionIndex(vi.Kills[0]).getRegSlot();
234 killIdx = defIndex.getDeadSlot();
236 // If the kill happens after the definition, we have an intra-block
238 if (killIdx > defIndex) {
239 assert(vi.AliveBlocks.empty() &&
240 "Shouldn't be alive across any blocks!");
241 LiveRange LR(defIndex, killIdx, ValNo);
242 interval.addRange(LR);
243 DEBUG(dbgs() << " +" << LR << "\n");
248 // The other case we handle is when a virtual register lives to the end
249 // of the defining block, potentially live across some blocks, then is
250 // live into some number of blocks, but gets killed. Start by adding a
251 // range that goes from this definition to the end of the defining block.
252 LiveRange NewLR(defIndex, getMBBEndIdx(mbb), ValNo);
253 DEBUG(dbgs() << " +" << NewLR);
254 interval.addRange(NewLR);
256 bool PHIJoin = LV->isPHIJoin(interval.reg);
259 // A phi join register is killed at the end of the MBB and revived as a
260 // new valno in the killing blocks.
261 assert(vi.AliveBlocks.empty() && "Phi join can't pass through blocks");
262 DEBUG(dbgs() << " phi-join");
264 // Iterate over all of the blocks that the variable is completely
265 // live in, adding [insrtIndex(begin), instrIndex(end)+4) to the
267 for (SparseBitVector<>::iterator I = vi.AliveBlocks.begin(),
268 E = vi.AliveBlocks.end(); I != E; ++I) {
269 MachineBasicBlock *aliveBlock = MF->getBlockNumbered(*I);
270 LiveRange LR(getMBBStartIdx(aliveBlock), getMBBEndIdx(aliveBlock),
272 interval.addRange(LR);
273 DEBUG(dbgs() << " +" << LR);
277 // Finally, this virtual register is live from the start of any killing
278 // block to the 'use' slot of the killing instruction.
279 for (unsigned i = 0, e = vi.Kills.size(); i != e; ++i) {
280 MachineInstr *Kill = vi.Kills[i];
281 SlotIndex Start = getMBBStartIdx(Kill->getParent());
282 SlotIndex killIdx = getInstructionIndex(Kill).getRegSlot();
284 // Create interval with one of a NEW value number. Note that this value
285 // number isn't actually defined by an instruction, weird huh? :)
287 assert(getInstructionFromIndex(Start) == 0 &&
288 "PHI def index points at actual instruction.");
289 ValNo = interval.getNextValue(Start, VNInfoAllocator);
291 LiveRange LR(Start, killIdx, ValNo);
292 interval.addRange(LR);
293 DEBUG(dbgs() << " +" << LR);
297 if (MultipleDefsBySameMI(*mi, MOIdx))
298 // Multiple defs of the same virtual register by the same instruction.
299 // e.g. %reg1031:5<def>, %reg1031:6<def> = VLD1q16 %reg1024<kill>, ...
300 // This is likely due to elimination of REG_SEQUENCE instructions. Return
301 // here since there is nothing to do.
304 // If this is the second time we see a virtual register definition, it
305 // must be due to phi elimination or two addr elimination. If this is
306 // the result of two address elimination, then the vreg is one of the
307 // def-and-use register operand.
309 // It may also be partial redef like this:
310 // 80 %reg1041:6<def> = VSHRNv4i16 %reg1034<kill>, 12, pred:14, pred:%reg0
311 // 120 %reg1041:5<def> = VSHRNv4i16 %reg1039<kill>, 12, pred:14, pred:%reg0
312 bool PartReDef = isPartialRedef(MIIdx, MO, interval);
313 if (PartReDef || mi->isRegTiedToUseOperand(MOIdx)) {
314 // If this is a two-address definition, then we have already processed
315 // the live range. The only problem is that we didn't realize there
316 // are actually two values in the live interval. Because of this we
317 // need to take the LiveRegion that defines this register and split it
319 SlotIndex RedefIndex = MIIdx.getRegSlot(MO.isEarlyClobber());
321 const LiveRange *OldLR =
322 interval.getLiveRangeContaining(RedefIndex.getRegSlot(true));
323 VNInfo *OldValNo = OldLR->valno;
324 SlotIndex DefIndex = OldValNo->def.getRegSlot();
326 // Delete the previous value, which should be short and continuous,
327 // because the 2-addr copy must be in the same MBB as the redef.
328 interval.removeRange(DefIndex, RedefIndex);
330 // The new value number (#1) is defined by the instruction we claimed
332 VNInfo *ValNo = interval.createValueCopy(OldValNo, VNInfoAllocator);
334 // Value#0 is now defined by the 2-addr instruction.
335 OldValNo->def = RedefIndex;
337 // Add the new live interval which replaces the range for the input copy.
338 LiveRange LR(DefIndex, RedefIndex, ValNo);
339 DEBUG(dbgs() << " replace range with " << LR);
340 interval.addRange(LR);
342 // If this redefinition is dead, we need to add a dummy unit live
343 // range covering the def slot.
345 interval.addRange(LiveRange(RedefIndex, RedefIndex.getDeadSlot(),
348 DEBUG(dbgs() << " RESULT: " << interval);
349 } else if (LV->isPHIJoin(interval.reg)) {
350 // In the case of PHI elimination, each variable definition is only
351 // live until the end of the block. We've already taken care of the
352 // rest of the live range.
354 SlotIndex defIndex = MIIdx.getRegSlot();
355 if (MO.isEarlyClobber())
356 defIndex = MIIdx.getRegSlot(true);
358 VNInfo *ValNo = interval.getNextValue(defIndex, VNInfoAllocator);
360 SlotIndex killIndex = getMBBEndIdx(mbb);
361 LiveRange LR(defIndex, killIndex, ValNo);
362 interval.addRange(LR);
363 DEBUG(dbgs() << " phi-join +" << LR);
365 llvm_unreachable("Multiply defined register");
369 DEBUG(dbgs() << '\n');
372 void LiveIntervals::handleRegisterDef(MachineBasicBlock *MBB,
373 MachineBasicBlock::iterator MI,
377 if (TargetRegisterInfo::isVirtualRegister(MO.getReg()))
378 handleVirtualRegisterDef(MBB, MI, MIIdx, MO, MOIdx,
379 getOrCreateInterval(MO.getReg()));
382 /// computeIntervals - computes the live intervals for virtual
383 /// registers. for some ordering of the machine instructions [1,N] a
384 /// live interval is an interval [i, j) where 1 <= i <= j < N for
385 /// which a variable is live
386 void LiveIntervals::computeIntervals() {
387 DEBUG(dbgs() << "********** COMPUTING LIVE INTERVALS **********\n"
388 << "********** Function: " << MF->getName() << '\n');
390 RegMaskBlocks.resize(MF->getNumBlockIDs());
392 SmallVector<unsigned, 8> UndefUses;
393 for (MachineFunction::iterator MBBI = MF->begin(), E = MF->end();
395 MachineBasicBlock *MBB = MBBI;
396 RegMaskBlocks[MBB->getNumber()].first = RegMaskSlots.size();
401 // Track the index of the current machine instr.
402 SlotIndex MIIndex = getMBBStartIdx(MBB);
403 DEBUG(dbgs() << "BB#" << MBB->getNumber()
404 << ":\t\t# derived from " << MBB->getName() << "\n");
406 // Skip over empty initial indices.
407 if (getInstructionFromIndex(MIIndex) == 0)
408 MIIndex = Indexes->getNextNonNullIndex(MIIndex);
410 for (MachineBasicBlock::iterator MI = MBB->begin(), miEnd = MBB->end();
412 DEBUG(dbgs() << MIIndex << "\t" << *MI);
413 if (MI->isDebugValue())
415 assert(Indexes->getInstructionFromIndex(MIIndex) == MI &&
416 "Lost SlotIndex synchronization");
419 for (int i = MI->getNumOperands() - 1; i >= 0; --i) {
420 MachineOperand &MO = MI->getOperand(i);
422 // Collect register masks.
423 if (MO.isRegMask()) {
424 RegMaskSlots.push_back(MIIndex.getRegSlot());
425 RegMaskBits.push_back(MO.getRegMask());
429 if (!MO.isReg() || !TargetRegisterInfo::isVirtualRegister(MO.getReg()))
432 // handle register defs - build intervals
434 handleRegisterDef(MBB, MI, MIIndex, MO, i);
435 else if (MO.isUndef())
436 UndefUses.push_back(MO.getReg());
439 // Move to the next instr slot.
440 MIIndex = Indexes->getNextNonNullIndex(MIIndex);
443 // Compute the number of register mask instructions in this block.
444 std::pair<unsigned, unsigned> &RMB = RegMaskBlocks[MBB->getNumber()];
445 RMB.second = RegMaskSlots.size() - RMB.first;
448 // Create empty intervals for registers defined by implicit_def's (except
449 // for those implicit_def that define values which are liveout of their
451 for (unsigned i = 0, e = UndefUses.size(); i != e; ++i) {
452 unsigned UndefReg = UndefUses[i];
453 (void)getOrCreateInterval(UndefReg);
457 LiveInterval* LiveIntervals::createInterval(unsigned reg) {
458 float Weight = TargetRegisterInfo::isPhysicalRegister(reg) ? HUGE_VALF : 0.0F;
459 return new LiveInterval(reg, Weight);
463 /// computeVirtRegInterval - Compute the live interval of a virtual register,
464 /// based on defs and uses.
465 void LiveIntervals::computeVirtRegInterval(LiveInterval *LI) {
466 assert(LRCalc && "LRCalc not initialized.");
467 assert(LI->empty() && "Should only compute empty intervals.");
468 LRCalc->reset(MF, getSlotIndexes(), DomTree, &getVNInfoAllocator());
469 LRCalc->createDeadDefs(LI);
470 LRCalc->extendToUses(LI);
473 void LiveIntervals::computeVirtRegs() {
474 for (unsigned i = 0, e = MRI->getNumVirtRegs(); i != e; ++i) {
475 unsigned Reg = TargetRegisterInfo::index2VirtReg(i);
476 if (MRI->reg_nodbg_empty(Reg))
478 LiveInterval *LI = createInterval(Reg);
479 VirtRegIntervals[Reg] = LI;
480 computeVirtRegInterval(LI);
484 void LiveIntervals::computeRegMasks() {
485 RegMaskBlocks.resize(MF->getNumBlockIDs());
487 // Find all instructions with regmask operands.
488 for (MachineFunction::iterator MBBI = MF->begin(), E = MF->end();
490 MachineBasicBlock *MBB = MBBI;
491 std::pair<unsigned, unsigned> &RMB = RegMaskBlocks[MBB->getNumber()];
492 RMB.first = RegMaskSlots.size();
493 for (MachineBasicBlock::iterator MI = MBB->begin(), ME = MBB->end();
495 for (MIOperands MO(MI); MO.isValid(); ++MO) {
496 if (!MO->isRegMask())
498 RegMaskSlots.push_back(Indexes->getInstructionIndex(MI).getRegSlot());
499 RegMaskBits.push_back(MO->getRegMask());
501 // Compute the number of register mask instructions in this block.
502 RMB.second = RegMaskSlots.size() - RMB.first;
506 //===----------------------------------------------------------------------===//
507 // Register Unit Liveness
508 //===----------------------------------------------------------------------===//
510 // Fixed interference typically comes from ABI boundaries: Function arguments
511 // and return values are passed in fixed registers, and so are exception
512 // pointers entering landing pads. Certain instructions require values to be
513 // present in specific registers. That is also represented through fixed
517 /// computeRegUnitInterval - Compute the live interval of a register unit, based
518 /// on the uses and defs of aliasing registers. The interval should be empty,
519 /// or contain only dead phi-defs from ABI blocks.
520 void LiveIntervals::computeRegUnitInterval(LiveInterval *LI) {
521 unsigned Unit = LI->reg;
523 assert(LRCalc && "LRCalc not initialized.");
524 LRCalc->reset(MF, getSlotIndexes(), DomTree, &getVNInfoAllocator());
526 // The physregs aliasing Unit are the roots and their super-registers.
527 // Create all values as dead defs before extending to uses. Note that roots
528 // may share super-registers. That's OK because createDeadDefs() is
529 // idempotent. It is very rare for a register unit to have multiple roots, so
530 // uniquing super-registers is probably not worthwhile.
531 for (MCRegUnitRootIterator Roots(Unit, TRI); Roots.isValid(); ++Roots) {
532 unsigned Root = *Roots;
533 if (!MRI->reg_empty(Root))
534 LRCalc->createDeadDefs(LI, Root);
535 for (MCSuperRegIterator Supers(Root, TRI); Supers.isValid(); ++Supers) {
536 if (!MRI->reg_empty(*Supers))
537 LRCalc->createDeadDefs(LI, *Supers);
541 // Now extend LI to reach all uses.
542 // Ignore uses of reserved registers. We only track defs of those.
543 for (MCRegUnitRootIterator Roots(Unit, TRI); Roots.isValid(); ++Roots) {
544 unsigned Root = *Roots;
545 if (!isReserved(Root) && !MRI->reg_empty(Root))
546 LRCalc->extendToUses(LI, Root);
547 for (MCSuperRegIterator Supers(Root, TRI); Supers.isValid(); ++Supers) {
548 unsigned Reg = *Supers;
549 if (!isReserved(Reg) && !MRI->reg_empty(Reg))
550 LRCalc->extendToUses(LI, Reg);
556 /// computeLiveInRegUnits - Precompute the live ranges of any register units
557 /// that are live-in to an ABI block somewhere. Register values can appear
558 /// without a corresponding def when entering the entry block or a landing pad.
560 void LiveIntervals::computeLiveInRegUnits() {
561 RegUnitIntervals.resize(TRI->getNumRegUnits());
562 DEBUG(dbgs() << "Computing live-in reg-units in ABI blocks.\n");
564 // Keep track of the intervals allocated.
565 SmallVector<LiveInterval*, 8> NewIntvs;
567 // Check all basic blocks for live-ins.
568 for (MachineFunction::const_iterator MFI = MF->begin(), MFE = MF->end();
570 const MachineBasicBlock *MBB = MFI;
572 // We only care about ABI blocks: Entry + landing pads.
573 if ((MFI != MF->begin() && !MBB->isLandingPad()) || MBB->livein_empty())
576 // Create phi-defs at Begin for all live-in registers.
577 SlotIndex Begin = Indexes->getMBBStartIdx(MBB);
578 DEBUG(dbgs() << Begin << "\tBB#" << MBB->getNumber());
579 for (MachineBasicBlock::livein_iterator LII = MBB->livein_begin(),
580 LIE = MBB->livein_end(); LII != LIE; ++LII) {
581 for (MCRegUnitIterator Units(*LII, TRI); Units.isValid(); ++Units) {
582 unsigned Unit = *Units;
583 LiveInterval *Intv = RegUnitIntervals[Unit];
585 Intv = RegUnitIntervals[Unit] = new LiveInterval(Unit, HUGE_VALF);
586 NewIntvs.push_back(Intv);
588 VNInfo *VNI = Intv->createDeadDef(Begin, getVNInfoAllocator());
590 DEBUG(dbgs() << ' ' << PrintRegUnit(Unit, TRI) << '#' << VNI->id);
593 DEBUG(dbgs() << '\n');
595 DEBUG(dbgs() << "Created " << NewIntvs.size() << " new intervals.\n");
597 // Compute the 'normal' part of the intervals.
598 for (unsigned i = 0, e = NewIntvs.size(); i != e; ++i)
599 computeRegUnitInterval(NewIntvs[i]);
603 /// shrinkToUses - After removing some uses of a register, shrink its live
604 /// range to just the remaining uses. This method does not compute reaching
605 /// defs for new uses, and it doesn't remove dead defs.
606 bool LiveIntervals::shrinkToUses(LiveInterval *li,
607 SmallVectorImpl<MachineInstr*> *dead) {
608 DEBUG(dbgs() << "Shrink: " << *li << '\n');
609 assert(TargetRegisterInfo::isVirtualRegister(li->reg)
610 && "Can only shrink virtual registers");
611 // Find all the values used, including PHI kills.
612 SmallVector<std::pair<SlotIndex, VNInfo*>, 16> WorkList;
614 // Blocks that have already been added to WorkList as live-out.
615 SmallPtrSet<MachineBasicBlock*, 16> LiveOut;
617 // Visit all instructions reading li->reg.
618 for (MachineRegisterInfo::reg_iterator I = MRI->reg_begin(li->reg);
619 MachineInstr *UseMI = I.skipInstruction();) {
620 if (UseMI->isDebugValue() || !UseMI->readsVirtualRegister(li->reg))
622 SlotIndex Idx = getInstructionIndex(UseMI).getRegSlot();
623 LiveRangeQuery LRQ(*li, Idx);
624 VNInfo *VNI = LRQ.valueIn();
626 // This shouldn't happen: readsVirtualRegister returns true, but there is
627 // no live value. It is likely caused by a target getting <undef> flags
629 DEBUG(dbgs() << Idx << '\t' << *UseMI
630 << "Warning: Instr claims to read non-existent value in "
634 // Special case: An early-clobber tied operand reads and writes the
635 // register one slot early.
636 if (VNInfo *DefVNI = LRQ.valueDefined())
639 WorkList.push_back(std::make_pair(Idx, VNI));
642 // Create a new live interval with only minimal live segments per def.
643 LiveInterval NewLI(li->reg, 0);
644 for (LiveInterval::vni_iterator I = li->vni_begin(), E = li->vni_end();
649 NewLI.addRange(LiveRange(VNI->def, VNI->def.getDeadSlot(), VNI));
652 // Keep track of the PHIs that are in use.
653 SmallPtrSet<VNInfo*, 8> UsedPHIs;
655 // Extend intervals to reach all uses in WorkList.
656 while (!WorkList.empty()) {
657 SlotIndex Idx = WorkList.back().first;
658 VNInfo *VNI = WorkList.back().second;
660 const MachineBasicBlock *MBB = getMBBFromIndex(Idx.getPrevSlot());
661 SlotIndex BlockStart = getMBBStartIdx(MBB);
663 // Extend the live range for VNI to be live at Idx.
664 if (VNInfo *ExtVNI = NewLI.extendInBlock(BlockStart, Idx)) {
666 assert(ExtVNI == VNI && "Unexpected existing value number");
667 // Is this a PHIDef we haven't seen before?
668 if (!VNI->isPHIDef() || VNI->def != BlockStart || !UsedPHIs.insert(VNI))
670 // The PHI is live, make sure the predecessors are live-out.
671 for (MachineBasicBlock::const_pred_iterator PI = MBB->pred_begin(),
672 PE = MBB->pred_end(); PI != PE; ++PI) {
673 if (!LiveOut.insert(*PI))
675 SlotIndex Stop = getMBBEndIdx(*PI);
676 // A predecessor is not required to have a live-out value for a PHI.
677 if (VNInfo *PVNI = li->getVNInfoBefore(Stop))
678 WorkList.push_back(std::make_pair(Stop, PVNI));
683 // VNI is live-in to MBB.
684 DEBUG(dbgs() << " live-in at " << BlockStart << '\n');
685 NewLI.addRange(LiveRange(BlockStart, Idx, VNI));
687 // Make sure VNI is live-out from the predecessors.
688 for (MachineBasicBlock::const_pred_iterator PI = MBB->pred_begin(),
689 PE = MBB->pred_end(); PI != PE; ++PI) {
690 if (!LiveOut.insert(*PI))
692 SlotIndex Stop = getMBBEndIdx(*PI);
693 assert(li->getVNInfoBefore(Stop) == VNI &&
694 "Wrong value out of predecessor");
695 WorkList.push_back(std::make_pair(Stop, VNI));
699 // Handle dead values.
700 bool CanSeparate = false;
701 for (LiveInterval::vni_iterator I = li->vni_begin(), E = li->vni_end();
706 LiveInterval::iterator LII = NewLI.FindLiveRangeContaining(VNI->def);
707 assert(LII != NewLI.end() && "Missing live range for PHI");
708 if (LII->end != VNI->def.getDeadSlot())
710 if (VNI->isPHIDef()) {
711 // This is a dead PHI. Remove it.
713 NewLI.removeRange(*LII);
714 DEBUG(dbgs() << "Dead PHI at " << VNI->def << " may separate interval\n");
717 // This is a dead def. Make sure the instruction knows.
718 MachineInstr *MI = getInstructionFromIndex(VNI->def);
719 assert(MI && "No instruction defining live value");
720 MI->addRegisterDead(li->reg, TRI);
721 if (dead && MI->allDefsAreDead()) {
722 DEBUG(dbgs() << "All defs dead: " << VNI->def << '\t' << *MI);
728 // Move the trimmed ranges back.
729 li->ranges.swap(NewLI.ranges);
730 DEBUG(dbgs() << "Shrunk: " << *li << '\n');
734 void LiveIntervals::extendToIndices(LiveInterval *LI,
735 ArrayRef<SlotIndex> Indices) {
736 assert(LRCalc && "LRCalc not initialized.");
737 LRCalc->reset(MF, getSlotIndexes(), DomTree, &getVNInfoAllocator());
738 for (unsigned i = 0, e = Indices.size(); i != e; ++i)
739 LRCalc->extend(LI, Indices[i]);
742 void LiveIntervals::pruneValue(LiveInterval *LI, SlotIndex Kill,
743 SmallVectorImpl<SlotIndex> *EndPoints) {
744 LiveRangeQuery LRQ(*LI, Kill);
745 VNInfo *VNI = LRQ.valueOut();
749 MachineBasicBlock *KillMBB = Indexes->getMBBFromIndex(Kill);
750 SlotIndex MBBStart, MBBEnd;
751 tie(MBBStart, MBBEnd) = Indexes->getMBBRange(KillMBB);
753 // If VNI isn't live out from KillMBB, the value is trivially pruned.
754 if (LRQ.endPoint() < MBBEnd) {
755 LI->removeRange(Kill, LRQ.endPoint());
756 if (EndPoints) EndPoints->push_back(LRQ.endPoint());
760 // VNI is live out of KillMBB.
761 LI->removeRange(Kill, MBBEnd);
762 if (EndPoints) EndPoints->push_back(MBBEnd);
764 // Find all blocks that are reachable from MBB without leaving VNI's live
766 for (df_iterator<MachineBasicBlock*>
767 I = df_begin(KillMBB), E = df_end(KillMBB); I != E;) {
768 MachineBasicBlock *MBB = *I;
769 // KillMBB itself was already handled.
770 if (MBB == KillMBB) {
775 // Check if VNI is live in to MBB.
776 tie(MBBStart, MBBEnd) = Indexes->getMBBRange(MBB);
777 LiveRangeQuery LRQ(*LI, MBBStart);
778 if (LRQ.valueIn() != VNI) {
779 // This block isn't part of the VNI live range. Prune the search.
784 // Prune the search if VNI is killed in MBB.
785 if (LRQ.endPoint() < MBBEnd) {
786 LI->removeRange(MBBStart, LRQ.endPoint());
787 if (EndPoints) EndPoints->push_back(LRQ.endPoint());
792 // VNI is live through MBB.
793 LI->removeRange(MBBStart, MBBEnd);
794 if (EndPoints) EndPoints->push_back(MBBEnd);
799 //===----------------------------------------------------------------------===//
800 // Register allocator hooks.
803 void LiveIntervals::addKillFlags(const VirtRegMap *VRM) {
804 // Keep track of regunit ranges.
805 SmallVector<std::pair<LiveInterval*, LiveInterval::iterator>, 8> RU;
807 for (unsigned i = 0, e = MRI->getNumVirtRegs(); i != e; ++i) {
808 unsigned Reg = TargetRegisterInfo::index2VirtReg(i);
809 if (MRI->reg_nodbg_empty(Reg))
811 LiveInterval *LI = &getInterval(Reg);
815 // Find the regunit intervals for the assigned register. They may overlap
816 // the virtual register live range, cancelling any kills.
818 for (MCRegUnitIterator Units(VRM->getPhys(Reg), TRI); Units.isValid();
820 LiveInterval *RUInt = &getRegUnit(*Units);
823 RU.push_back(std::make_pair(RUInt, RUInt->find(LI->begin()->end)));
826 // Every instruction that kills Reg corresponds to a live range end point.
827 for (LiveInterval::iterator RI = LI->begin(), RE = LI->end(); RI != RE;
829 // A block index indicates an MBB edge.
830 if (RI->end.isBlock())
832 MachineInstr *MI = getInstructionFromIndex(RI->end);
836 // Check if any of the reguints are live beyond the end of RI. That could
837 // happen when a physreg is defined as a copy of a virtreg:
839 // %EAX = COPY %vreg5
840 // FOO %vreg5 <--- MI, cancel kill because %EAX is live.
843 // There should be no kill flag on FOO when %vreg5 is rewritten as %EAX.
844 bool CancelKill = false;
845 for (unsigned u = 0, e = RU.size(); u != e; ++u) {
846 LiveInterval *RInt = RU[u].first;
847 LiveInterval::iterator &I = RU[u].second;
848 if (I == RInt->end())
850 I = RInt->advanceTo(I, RI->end);
851 if (I == RInt->end() || I->start >= RI->end)
853 // I is overlapping RI.
858 MI->clearRegisterKills(Reg, NULL);
860 MI->addRegisterKilled(Reg, NULL);
866 LiveIntervals::intervalIsInOneMBB(const LiveInterval &LI) const {
867 // A local live range must be fully contained inside the block, meaning it is
868 // defined and killed at instructions, not at block boundaries. It is not
869 // live in or or out of any block.
871 // It is technically possible to have a PHI-defined live range identical to a
872 // single block, but we are going to return false in that case.
874 SlotIndex Start = LI.beginIndex();
878 SlotIndex Stop = LI.endIndex();
882 // getMBBFromIndex doesn't need to search the MBB table when both indexes
883 // belong to proper instructions.
884 MachineBasicBlock *MBB1 = Indexes->getMBBFromIndex(Start);
885 MachineBasicBlock *MBB2 = Indexes->getMBBFromIndex(Stop);
886 return MBB1 == MBB2 ? MBB1 : NULL;
890 LiveIntervals::hasPHIKill(const LiveInterval &LI, const VNInfo *VNI) const {
891 for (LiveInterval::const_vni_iterator I = LI.vni_begin(), E = LI.vni_end();
893 const VNInfo *PHI = *I;
894 if (PHI->isUnused() || !PHI->isPHIDef())
896 const MachineBasicBlock *PHIMBB = getMBBFromIndex(PHI->def);
897 // Conservatively return true instead of scanning huge predecessor lists.
898 if (PHIMBB->pred_size() > 100)
900 for (MachineBasicBlock::const_pred_iterator
901 PI = PHIMBB->pred_begin(), PE = PHIMBB->pred_end(); PI != PE; ++PI)
902 if (VNI == LI.getVNInfoBefore(Indexes->getMBBEndIdx(*PI)))
909 LiveIntervals::getSpillWeight(bool isDef, bool isUse, unsigned loopDepth) {
910 // Limit the loop depth ridiculousness.
914 // The loop depth is used to roughly estimate the number of times the
915 // instruction is executed. Something like 10^d is simple, but will quickly
916 // overflow a float. This expression behaves like 10^d for small d, but is
917 // more tempered for large d. At d=200 we get 6.7e33 which leaves a bit of
918 // headroom before overflow.
919 // By the way, powf() might be unavailable here. For consistency,
920 // We may take pow(double,double).
921 float lc = std::pow(1 + (100.0 / (loopDepth + 10)), (double)loopDepth);
923 return (isDef + isUse) * lc;
926 LiveRange LiveIntervals::addLiveRangeToEndOfBlock(unsigned reg,
927 MachineInstr* startInst) {
928 LiveInterval& Interval = getOrCreateInterval(reg);
929 VNInfo* VN = Interval.getNextValue(
930 SlotIndex(getInstructionIndex(startInst).getRegSlot()),
931 getVNInfoAllocator());
933 SlotIndex(getInstructionIndex(startInst).getRegSlot()),
934 getMBBEndIdx(startInst->getParent()), VN);
935 Interval.addRange(LR);
941 //===----------------------------------------------------------------------===//
942 // Register mask functions
943 //===----------------------------------------------------------------------===//
945 bool LiveIntervals::checkRegMaskInterference(LiveInterval &LI,
946 BitVector &UsableRegs) {
949 LiveInterval::iterator LiveI = LI.begin(), LiveE = LI.end();
951 // Use a smaller arrays for local live ranges.
952 ArrayRef<SlotIndex> Slots;
953 ArrayRef<const uint32_t*> Bits;
954 if (MachineBasicBlock *MBB = intervalIsInOneMBB(LI)) {
955 Slots = getRegMaskSlotsInBlock(MBB->getNumber());
956 Bits = getRegMaskBitsInBlock(MBB->getNumber());
958 Slots = getRegMaskSlots();
959 Bits = getRegMaskBits();
962 // We are going to enumerate all the register mask slots contained in LI.
963 // Start with a binary search of RegMaskSlots to find a starting point.
964 ArrayRef<SlotIndex>::iterator SlotI =
965 std::lower_bound(Slots.begin(), Slots.end(), LiveI->start);
966 ArrayRef<SlotIndex>::iterator SlotE = Slots.end();
968 // No slots in range, LI begins after the last call.
974 assert(*SlotI >= LiveI->start);
975 // Loop over all slots overlapping this segment.
976 while (*SlotI < LiveI->end) {
977 // *SlotI overlaps LI. Collect mask bits.
979 // This is the first overlap. Initialize UsableRegs to all ones.
981 UsableRegs.resize(TRI->getNumRegs(), true);
984 // Remove usable registers clobbered by this mask.
985 UsableRegs.clearBitsNotInMask(Bits[SlotI-Slots.begin()]);
986 if (++SlotI == SlotE)
989 // *SlotI is beyond the current LI segment.
990 LiveI = LI.advanceTo(LiveI, *SlotI);
993 // Advance SlotI until it overlaps.
994 while (*SlotI < LiveI->start)
995 if (++SlotI == SlotE)
1000 //===----------------------------------------------------------------------===//
1001 // IntervalUpdate class.
1002 //===----------------------------------------------------------------------===//
1004 // HMEditor is a toolkit used by handleMove to trim or extend live intervals.
1005 class LiveIntervals::HMEditor {
1008 const MachineRegisterInfo& MRI;
1009 const TargetRegisterInfo& TRI;
1012 typedef std::pair<LiveInterval*, LiveRange*> IntRangePair;
1013 typedef DenseSet<IntRangePair> RangeSet;
1020 RegRanges() : Use(0), EC(0), Dead(0), Def(0) {}
1022 typedef DenseMap<unsigned, RegRanges> BundleRanges;
1025 HMEditor(LiveIntervals& LIS, const MachineRegisterInfo& MRI,
1026 const TargetRegisterInfo& TRI, SlotIndex NewIdx)
1027 : LIS(LIS), MRI(MRI), TRI(TRI), NewIdx(NewIdx) {}
1029 // Update intervals for all operands of MI from OldIdx to NewIdx.
1030 // This assumes that MI used to be at OldIdx, and now resides at
1032 void moveAllRangesFrom(MachineInstr* MI, SlotIndex OldIdx) {
1033 assert(NewIdx != OldIdx && "No-op move? That's a bit strange.");
1035 // Collect the operands.
1036 RangeSet Entering, Internal, Exiting;
1037 bool hasRegMaskOp = false;
1038 collectRanges(MI, Entering, Internal, Exiting, hasRegMaskOp, OldIdx);
1040 // To keep the LiveRanges valid within an interval, move the ranges closest
1041 // to the destination first. This prevents ranges from overlapping, to that
1042 // APIs like removeRange still work.
1043 if (NewIdx < OldIdx) {
1044 moveAllEnteringFrom(OldIdx, Entering);
1045 moveAllInternalFrom(OldIdx, Internal);
1046 moveAllExitingFrom(OldIdx, Exiting);
1049 moveAllExitingFrom(OldIdx, Exiting);
1050 moveAllInternalFrom(OldIdx, Internal);
1051 moveAllEnteringFrom(OldIdx, Entering);
1055 updateRegMaskSlots(OldIdx);
1058 LIValidator validator;
1059 validator = std::for_each(Entering.begin(), Entering.end(), validator);
1060 validator = std::for_each(Internal.begin(), Internal.end(), validator);
1061 validator = std::for_each(Exiting.begin(), Exiting.end(), validator);
1062 assert(validator.rangesOk() && "moveAllOperandsFrom broke liveness.");
1067 // Update intervals for all operands of MI to refer to BundleStart's
1069 void moveAllRangesInto(MachineInstr* MI, MachineInstr* BundleStart) {
1070 if (MI == BundleStart)
1071 return; // Bundling instr with itself - nothing to do.
1073 SlotIndex OldIdx = LIS.getSlotIndexes()->getInstructionIndex(MI);
1074 assert(LIS.getSlotIndexes()->getInstructionFromIndex(OldIdx) == MI &&
1075 "SlotIndex <-> Instruction mapping broken for MI");
1077 // Collect all ranges already in the bundle.
1078 MachineBasicBlock::instr_iterator BII(BundleStart);
1079 RangeSet Entering, Internal, Exiting;
1080 bool hasRegMaskOp = false;
1081 collectRanges(BII, Entering, Internal, Exiting, hasRegMaskOp, NewIdx);
1082 assert(!hasRegMaskOp && "Can't have RegMask operand in bundle.");
1083 for (++BII; &*BII == MI || BII->isInsideBundle(); ++BII) {
1086 collectRanges(BII, Entering, Internal, Exiting, hasRegMaskOp, NewIdx);
1087 assert(!hasRegMaskOp && "Can't have RegMask operand in bundle.");
1090 BundleRanges BR = createBundleRanges(Entering, Internal, Exiting);
1095 collectRanges(MI, Entering, Internal, Exiting, hasRegMaskOp, OldIdx);
1096 assert(!hasRegMaskOp && "Can't have RegMask operand in bundle.");
1098 DEBUG(dbgs() << "Entering: " << Entering.size() << "\n");
1099 DEBUG(dbgs() << "Internal: " << Internal.size() << "\n");
1100 DEBUG(dbgs() << "Exiting: " << Exiting.size() << "\n");
1102 moveAllEnteringFromInto(OldIdx, Entering, BR);
1103 moveAllInternalFromInto(OldIdx, Internal, BR);
1104 moveAllExitingFromInto(OldIdx, Exiting, BR);
1108 LIValidator validator;
1109 validator = std::for_each(Entering.begin(), Entering.end(), validator);
1110 validator = std::for_each(Internal.begin(), Internal.end(), validator);
1111 validator = std::for_each(Exiting.begin(), Exiting.end(), validator);
1112 assert(validator.rangesOk() && "moveAllOperandsInto broke liveness.");
1121 DenseSet<const LiveInterval*> Checked, Bogus;
1123 void operator()(const IntRangePair& P) {
1124 const LiveInterval* LI = P.first;
1125 if (Checked.count(LI))
1130 SlotIndex LastEnd = LI->begin()->start;
1131 for (LiveInterval::const_iterator LRI = LI->begin(), LRE = LI->end();
1132 LRI != LRE; ++LRI) {
1133 const LiveRange& LR = *LRI;
1134 if (LastEnd > LR.start || LR.start >= LR.end)
1140 bool rangesOk() const {
1141 return Bogus.empty();
1146 // Collect IntRangePairs for all operands of MI that may need fixing.
1147 // Treat's MI's index as OldIdx (regardless of what it is in SlotIndexes'
1149 void collectRanges(MachineInstr* MI, RangeSet& Entering, RangeSet& Internal,
1150 RangeSet& Exiting, bool& hasRegMaskOp, SlotIndex OldIdx) {
1151 hasRegMaskOp = false;
1152 for (MachineInstr::mop_iterator MOI = MI->operands_begin(),
1153 MOE = MI->operands_end();
1154 MOI != MOE; ++MOI) {
1155 const MachineOperand& MO = *MOI;
1157 if (MO.isRegMask()) {
1158 hasRegMaskOp = true;
1162 if (!MO.isReg() || MO.getReg() == 0)
1165 unsigned Reg = MO.getReg();
1167 // Don't track uses of reserved registers - they're not accurate.
1168 // Reserved register live ranges look like a set of dead defs.
1170 TargetRegisterInfo::isPhysicalRegister(Reg) && LIS.isReserved(Reg);
1172 // Collect ranges for register units. These live ranges are computed on
1173 // demand, so just skip any that haven't been computed yet.
1174 if (TargetRegisterInfo::isPhysicalRegister(Reg)) {
1175 for (MCRegUnitIterator Units(Reg, &TRI); Units.isValid(); ++Units)
1176 if (LiveInterval *LI = LIS.getCachedRegUnit(*Units))
1177 collectRanges(MO, LI, Entering, Internal, Exiting, OldIdx, Resv);
1179 // Collect ranges for individual virtual registers.
1180 collectRanges(MO, &LIS.getInterval(Reg),
1181 Entering, Internal, Exiting, OldIdx);
1186 void collectRanges(const MachineOperand &MO, LiveInterval *LI,
1187 RangeSet &Entering, RangeSet &Internal, RangeSet &Exiting,
1188 SlotIndex OldIdx, bool IgnoreReads = false) {
1189 if (!IgnoreReads && MO.readsReg()) {
1190 LiveRange* LR = LI->getLiveRangeContaining(OldIdx);
1192 Entering.insert(std::make_pair(LI, LR));
1195 LiveRange* LR = LI->getLiveRangeContaining(OldIdx.getRegSlot());
1196 assert(LR != 0 && "No live range for def?");
1197 if (LR->end > OldIdx.getDeadSlot())
1198 Exiting.insert(std::make_pair(LI, LR));
1200 Internal.insert(std::make_pair(LI, LR));
1204 BundleRanges createBundleRanges(RangeSet& Entering,
1206 RangeSet& Exiting) {
1209 for (RangeSet::iterator EI = Entering.begin(), EE = Entering.end();
1211 LiveInterval* LI = EI->first;
1212 LiveRange* LR = EI->second;
1213 BR[LI->reg].Use = LR;
1216 for (RangeSet::iterator II = Internal.begin(), IE = Internal.end();
1218 LiveInterval* LI = II->first;
1219 LiveRange* LR = II->second;
1220 if (LR->end.isDead()) {
1221 BR[LI->reg].Dead = LR;
1223 BR[LI->reg].EC = LR;
1227 for (RangeSet::iterator EI = Exiting.begin(), EE = Exiting.end();
1229 LiveInterval* LI = EI->first;
1230 LiveRange* LR = EI->second;
1231 BR[LI->reg].Def = LR;
1237 void moveKillFlags(unsigned reg, SlotIndex OldIdx, SlotIndex newKillIdx) {
1238 MachineInstr* OldKillMI = LIS.getInstructionFromIndex(OldIdx);
1239 if (!OldKillMI->killsRegister(reg))
1240 return; // Bail out if we don't have kill flags on the old register.
1241 MachineInstr* NewKillMI = LIS.getInstructionFromIndex(newKillIdx);
1242 assert(OldKillMI->killsRegister(reg) && "Old 'kill' instr isn't a kill.");
1243 assert(!NewKillMI->killsRegister(reg) &&
1244 "New kill instr is already a kill.");
1245 OldKillMI->clearRegisterKills(reg, &TRI);
1246 NewKillMI->addRegisterKilled(reg, &TRI);
1249 void updateRegMaskSlots(SlotIndex OldIdx) {
1250 SmallVectorImpl<SlotIndex>::iterator RI =
1251 std::lower_bound(LIS.RegMaskSlots.begin(), LIS.RegMaskSlots.end(),
1253 assert(*RI == OldIdx && "No RegMask at OldIdx.");
1255 assert(*prior(RI) < *RI && *RI < *next(RI) &&
1256 "RegSlots out of order. Did you move one call across another?");
1259 // Return the last use of reg between NewIdx and OldIdx.
1260 SlotIndex findLastUseBefore(unsigned Reg, SlotIndex OldIdx) {
1261 SlotIndex LastUse = NewIdx;
1263 if (TargetRegisterInfo::isVirtualRegister(Reg)) {
1264 for (MachineRegisterInfo::use_nodbg_iterator
1265 UI = MRI.use_nodbg_begin(Reg),
1266 UE = MRI.use_nodbg_end();
1267 UI != UE; UI.skipInstruction()) {
1268 const MachineInstr* MI = &*UI;
1269 SlotIndex InstSlot = LIS.getSlotIndexes()->getInstructionIndex(MI);
1270 if (InstSlot > LastUse && InstSlot < OldIdx)
1274 MachineInstr* MI = LIS.getSlotIndexes()->getInstructionFromIndex(NewIdx);
1275 MachineBasicBlock::iterator MII(MI);
1277 MachineBasicBlock* MBB = MI->getParent();
1278 for (; MII != MBB->end() && LIS.getInstructionIndex(MII) < OldIdx; ++MII){
1279 for (MachineInstr::mop_iterator MOI = MII->operands_begin(),
1280 MOE = MII->operands_end();
1281 MOI != MOE; ++MOI) {
1282 const MachineOperand& mop = *MOI;
1283 if (!mop.isReg() || mop.getReg() == 0 ||
1284 TargetRegisterInfo::isVirtualRegister(mop.getReg()))
1287 if (TRI.hasRegUnit(mop.getReg(), Reg))
1288 LastUse = LIS.getInstructionIndex(MII);
1295 void moveEnteringUpFrom(SlotIndex OldIdx, IntRangePair& P) {
1296 LiveInterval* LI = P.first;
1297 LiveRange* LR = P.second;
1298 bool LiveThrough = LR->end > OldIdx.getRegSlot();
1301 SlotIndex LastUse = findLastUseBefore(LI->reg, OldIdx);
1302 if (LastUse != NewIdx)
1303 moveKillFlags(LI->reg, NewIdx, LastUse);
1304 LR->end = LastUse.getRegSlot(LR->end.isEarlyClobber());
1307 void moveEnteringDownFrom(SlotIndex OldIdx, IntRangePair& P) {
1308 LiveInterval* LI = P.first;
1309 LiveRange* LR = P.second;
1310 // Extend the LiveRange if NewIdx is past the end.
1311 if (NewIdx > LR->end) {
1312 // Move kill flags if OldIdx was not originally the end
1313 // (otherwise LR->end points to an invalid slot).
1314 if (LR->end.getRegSlot() != OldIdx.getRegSlot()) {
1315 assert(LR->end > OldIdx && "LiveRange does not cover original slot");
1316 moveKillFlags(LI->reg, LR->end, NewIdx);
1318 LR->end = NewIdx.getRegSlot(LR->end.isEarlyClobber());
1322 void moveAllEnteringFrom(SlotIndex OldIdx, RangeSet& Entering) {
1323 bool GoingUp = NewIdx < OldIdx;
1326 for (RangeSet::iterator EI = Entering.begin(), EE = Entering.end();
1328 moveEnteringUpFrom(OldIdx, *EI);
1330 for (RangeSet::iterator EI = Entering.begin(), EE = Entering.end();
1332 moveEnteringDownFrom(OldIdx, *EI);
1336 void moveInternalFrom(SlotIndex OldIdx, IntRangePair& P) {
1337 LiveInterval* LI = P.first;
1338 LiveRange* LR = P.second;
1339 assert(OldIdx < LR->start && LR->start < OldIdx.getDeadSlot() &&
1340 LR->end <= OldIdx.getDeadSlot() &&
1341 "Range should be internal to OldIdx.");
1343 Tmp.start = NewIdx.getRegSlot(LR->start.isEarlyClobber());
1344 Tmp.valno->def = Tmp.start;
1345 Tmp.end = LR->end.isDead() ? NewIdx.getDeadSlot() : NewIdx.getRegSlot();
1346 LI->removeRange(*LR);
1350 void moveAllInternalFrom(SlotIndex OldIdx, RangeSet& Internal) {
1351 for (RangeSet::iterator II = Internal.begin(), IE = Internal.end();
1353 moveInternalFrom(OldIdx, *II);
1356 void moveExitingFrom(SlotIndex OldIdx, IntRangePair& P) {
1357 LiveRange* LR = P.second;
1358 assert(OldIdx < LR->start && LR->start < OldIdx.getDeadSlot() &&
1359 "Range should start in OldIdx.");
1360 assert(LR->end > OldIdx.getDeadSlot() && "Range should exit OldIdx.");
1361 SlotIndex NewStart = NewIdx.getRegSlot(LR->start.isEarlyClobber());
1362 LR->start = NewStart;
1363 LR->valno->def = NewStart;
1366 void moveAllExitingFrom(SlotIndex OldIdx, RangeSet& Exiting) {
1367 for (RangeSet::iterator EI = Exiting.begin(), EE = Exiting.end();
1369 moveExitingFrom(OldIdx, *EI);
1372 void moveEnteringUpFromInto(SlotIndex OldIdx, IntRangePair& P,
1374 LiveInterval* LI = P.first;
1375 LiveRange* LR = P.second;
1376 bool LiveThrough = LR->end > OldIdx.getRegSlot();
1378 assert((LR->start < NewIdx || BR[LI->reg].Def == LR) &&
1379 "Def in bundle should be def range.");
1380 assert((BR[LI->reg].Use == 0 || BR[LI->reg].Use == LR) &&
1381 "If bundle has use for this reg it should be LR.");
1382 BR[LI->reg].Use = LR;
1386 SlotIndex LastUse = findLastUseBefore(LI->reg, OldIdx);
1387 moveKillFlags(LI->reg, OldIdx, LastUse);
1389 if (LR->start < NewIdx) {
1390 // Becoming a new entering range.
1391 assert(BR[LI->reg].Dead == 0 && BR[LI->reg].Def == 0 &&
1392 "Bundle shouldn't be re-defining reg mid-range.");
1393 assert((BR[LI->reg].Use == 0 || BR[LI->reg].Use == LR) &&
1394 "Bundle shouldn't have different use range for same reg.");
1395 LR->end = LastUse.getRegSlot();
1396 BR[LI->reg].Use = LR;
1398 // Becoming a new Dead-def.
1399 assert(LR->start == NewIdx.getRegSlot(LR->start.isEarlyClobber()) &&
1400 "Live range starting at unexpected slot.");
1401 assert(BR[LI->reg].Def == LR && "Reg should have def range.");
1402 assert(BR[LI->reg].Dead == 0 &&
1403 "Can't have def and dead def of same reg in a bundle.");
1404 LR->end = LastUse.getDeadSlot();
1405 BR[LI->reg].Dead = BR[LI->reg].Def;
1406 BR[LI->reg].Def = 0;
1410 void moveEnteringDownFromInto(SlotIndex OldIdx, IntRangePair& P,
1412 LiveInterval* LI = P.first;
1413 LiveRange* LR = P.second;
1414 if (NewIdx > LR->end) {
1415 // Range extended to bundle. Add to bundle uses.
1416 // Note: Currently adds kill flags to bundle start.
1417 assert(BR[LI->reg].Use == 0 &&
1418 "Bundle already has use range for reg.");
1419 moveKillFlags(LI->reg, LR->end, NewIdx);
1420 LR->end = NewIdx.getRegSlot();
1421 BR[LI->reg].Use = LR;
1423 assert(BR[LI->reg].Use != 0 &&
1424 "Bundle should already have a use range for reg.");
1428 void moveAllEnteringFromInto(SlotIndex OldIdx, RangeSet& Entering,
1430 bool GoingUp = NewIdx < OldIdx;
1433 for (RangeSet::iterator EI = Entering.begin(), EE = Entering.end();
1435 moveEnteringUpFromInto(OldIdx, *EI, BR);
1437 for (RangeSet::iterator EI = Entering.begin(), EE = Entering.end();
1439 moveEnteringDownFromInto(OldIdx, *EI, BR);
1443 void moveInternalFromInto(SlotIndex OldIdx, IntRangePair& P,
1445 // TODO: Sane rules for moving ranges into bundles.
1448 void moveAllInternalFromInto(SlotIndex OldIdx, RangeSet& Internal,
1450 for (RangeSet::iterator II = Internal.begin(), IE = Internal.end();
1452 moveInternalFromInto(OldIdx, *II, BR);
1455 void moveExitingFromInto(SlotIndex OldIdx, IntRangePair& P,
1457 LiveInterval* LI = P.first;
1458 LiveRange* LR = P.second;
1460 assert(LR->start.isRegister() &&
1461 "Don't know how to merge exiting ECs into bundles yet.");
1463 if (LR->end > NewIdx.getDeadSlot()) {
1464 // This range is becoming an exiting range on the bundle.
1465 // If there was an old dead-def of this reg, delete it.
1466 if (BR[LI->reg].Dead != 0) {
1467 LI->removeRange(*BR[LI->reg].Dead);
1468 BR[LI->reg].Dead = 0;
1470 assert(BR[LI->reg].Def == 0 &&
1471 "Can't have two defs for the same variable exiting a bundle.");
1472 LR->start = NewIdx.getRegSlot();
1473 LR->valno->def = LR->start;
1474 BR[LI->reg].Def = LR;
1476 // This range is becoming internal to the bundle.
1477 assert(LR->end == NewIdx.getRegSlot() &&
1478 "Can't bundle def whose kill is before the bundle");
1479 if (BR[LI->reg].Dead || BR[LI->reg].Def) {
1480 // Already have a def for this. Just delete range.
1481 LI->removeRange(*LR);
1483 // Make range dead, record.
1484 LR->end = NewIdx.getDeadSlot();
1485 BR[LI->reg].Dead = LR;
1486 assert(BR[LI->reg].Use == LR &&
1487 "Range becoming dead should currently be use.");
1489 // In both cases the range is no longer a use on the bundle.
1490 BR[LI->reg].Use = 0;
1494 void moveAllExitingFromInto(SlotIndex OldIdx, RangeSet& Exiting,
1496 for (RangeSet::iterator EI = Exiting.begin(), EE = Exiting.end();
1498 moveExitingFromInto(OldIdx, *EI, BR);
1503 void LiveIntervals::handleMove(MachineInstr* MI) {
1504 SlotIndex OldIndex = Indexes->getInstructionIndex(MI);
1505 Indexes->removeMachineInstrFromMaps(MI);
1506 SlotIndex NewIndex = MI->isInsideBundle() ?
1507 Indexes->getInstructionIndex(MI) :
1508 Indexes->insertMachineInstrInMaps(MI);
1509 assert(getMBBStartIdx(MI->getParent()) <= OldIndex &&
1510 OldIndex < getMBBEndIdx(MI->getParent()) &&
1511 "Cannot handle moves across basic block boundaries.");
1512 assert(!MI->isBundled() && "Can't handle bundled instructions yet.");
1514 HMEditor HME(*this, *MRI, *TRI, NewIndex);
1515 HME.moveAllRangesFrom(MI, OldIndex);
1518 void LiveIntervals::handleMoveIntoBundle(MachineInstr* MI,
1519 MachineInstr* BundleStart) {
1520 SlotIndex NewIndex = Indexes->getInstructionIndex(BundleStart);
1521 HMEditor HME(*this, *MRI, *TRI, NewIndex);
1522 HME.moveAllRangesInto(MI, BundleStart);