1 //===- LiveDebugVariables.cpp - Tracking debug info variables -------------===//
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 LiveDebugVariables analysis.
12 // Remove all DBG_VALUE instructions referencing virtual registers and replace
13 // them with a data structure tracking where live user variables are kept - in a
14 // virtual register or in a stack slot.
16 // Allow the data structure to be updated during register allocation when values
17 // are moved between registers and stack slots. Finally emit new DBG_VALUE
18 // instructions after register allocation is complete.
20 //===----------------------------------------------------------------------===//
22 #define DEBUG_TYPE "livedebug"
23 #include "LiveDebugVariables.h"
24 #include "VirtRegMap.h"
25 #include "llvm/Constants.h"
26 #include "llvm/Metadata.h"
27 #include "llvm/Value.h"
28 #include "llvm/ADT/IntervalMap.h"
29 #include "llvm/CodeGen/LiveIntervalAnalysis.h"
30 #include "llvm/CodeGen/MachineDominators.h"
31 #include "llvm/CodeGen/MachineFunction.h"
32 #include "llvm/CodeGen/MachineInstrBuilder.h"
33 #include "llvm/CodeGen/MachineRegisterInfo.h"
34 #include "llvm/CodeGen/Passes.h"
35 #include "llvm/Support/CommandLine.h"
36 #include "llvm/Support/Debug.h"
37 #include "llvm/Target/TargetInstrInfo.h"
38 #include "llvm/Target/TargetMachine.h"
39 #include "llvm/Target/TargetRegisterInfo.h"
44 EnableLDV("live-debug-variables", cl::init(true),
45 cl::desc("Enable the live debug variables pass"), cl::Hidden);
47 char LiveDebugVariables::ID = 0;
49 INITIALIZE_PASS_BEGIN(LiveDebugVariables, "livedebugvars",
50 "Debug Variable Analysis", false, false)
51 INITIALIZE_PASS_DEPENDENCY(MachineDominatorTree)
52 INITIALIZE_PASS_DEPENDENCY(LiveIntervals)
53 INITIALIZE_PASS_END(LiveDebugVariables, "livedebugvars",
54 "Debug Variable Analysis", false, false)
56 void LiveDebugVariables::getAnalysisUsage(AnalysisUsage &AU) const {
57 AU.addRequired<MachineDominatorTree>();
58 AU.addRequiredTransitive<LiveIntervals>();
60 MachineFunctionPass::getAnalysisUsage(AU);
63 LiveDebugVariables::LiveDebugVariables() : MachineFunctionPass(ID), pImpl(0) {
64 initializeLiveDebugVariablesPass(*PassRegistry::getPassRegistry());
67 /// LocMap - Map of where a user value is live, and its location.
68 typedef IntervalMap<SlotIndex, unsigned, 4> LocMap;
70 /// UserValue - A user value is a part of a debug info user variable.
72 /// A DBG_VALUE instruction notes that (a sub-register of) a virtual register
73 /// holds part of a user variable. The part is identified by a byte offset.
75 /// UserValues are grouped into equivalence classes for easier searching. Two
76 /// user values are related if they refer to the same variable, or if they are
77 /// held by the same virtual register. The equivalence class is the transitive
78 /// closure of that relation.
82 const MDNode *variable; ///< The debug info variable we are part of.
83 unsigned offset; ///< Byte offset into variable.
84 DebugLoc dl; ///< The debug location for the variable. This is
85 ///< used by dwarf writer to find lexical scope.
86 UserValue *leader; ///< Equivalence class leader.
87 UserValue *next; ///< Next value in equivalence class, or null.
89 /// Numbered locations referenced by locmap.
90 SmallVector<MachineOperand, 4> locations;
92 /// Map of slot indices where this value is live.
95 /// coalesceLocation - After LocNo was changed, check if it has become
96 /// identical to another location, and coalesce them. This may cause LocNo or
97 /// a later location to be erased, but no earlier location will be erased.
98 void coalesceLocation(unsigned LocNo);
100 /// insertDebugValue - Insert a DBG_VALUE into MBB at Idx for LocNo.
101 void insertDebugValue(MachineBasicBlock *MBB, SlotIndex Idx, unsigned LocNo,
102 LiveIntervals &LIS, const TargetInstrInfo &TII);
104 /// insertDebugKill - Insert an undef DBG_VALUE into MBB at Idx.
105 void insertDebugKill(MachineBasicBlock *MBB, SlotIndex Idx,
106 LiveIntervals &LIS, const TargetInstrInfo &TII);
109 /// UserValue - Create a new UserValue.
110 UserValue(const MDNode *var, unsigned o, DebugLoc L,
111 LocMap::Allocator &alloc)
112 : variable(var), offset(o), dl(L), leader(this), next(0), locInts(alloc)
115 /// getLeader - Get the leader of this value's equivalence class.
116 UserValue *getLeader() {
117 UserValue *l = leader;
118 while (l != l->leader)
123 /// getNext - Return the next UserValue in the equivalence class.
124 UserValue *getNext() const { return next; }
126 /// match - Does this UserValue match the aprameters?
127 bool match(const MDNode *Var, unsigned Offset) const {
128 return Var == variable && Offset == offset;
131 /// merge - Merge equivalence classes.
132 static UserValue *merge(UserValue *L1, UserValue *L2) {
133 L2 = L2->getLeader();
136 L1 = L1->getLeader();
139 // Splice L2 before L1's members.
142 End->leader = L1, End = End->next;
144 End->next = L1->next;
149 /// getLocationNo - Return the location number that matches Loc.
150 unsigned getLocationNo(const MachineOperand &LocMO) {
152 if (LocMO.getReg() == 0)
154 // For register locations we dont care about use/def and other flags.
155 for (unsigned i = 0, e = locations.size(); i != e; ++i)
156 if (locations[i].isReg() &&
157 locations[i].getReg() == LocMO.getReg() &&
158 locations[i].getSubReg() == LocMO.getSubReg())
161 for (unsigned i = 0, e = locations.size(); i != e; ++i)
162 if (LocMO.isIdenticalTo(locations[i]))
164 locations.push_back(LocMO);
165 // We are storing a MachineOperand outside a MachineInstr.
166 locations.back().clearParent();
167 // Don't store def operands.
168 if (locations.back().isReg())
169 locations.back().setIsUse();
170 return locations.size() - 1;
173 /// mapVirtRegs - Ensure that all virtual register locations are mapped.
174 void mapVirtRegs(LDVImpl *LDV);
176 /// addDef - Add a definition point to this value.
177 void addDef(SlotIndex Idx, const MachineOperand &LocMO) {
178 // Add a singular (Idx,Idx) -> Loc mapping.
179 LocMap::iterator I = locInts.find(Idx);
180 if (!I.valid() || I.start() != Idx)
181 I.insert(Idx, Idx.getNextSlot(), getLocationNo(LocMO));
184 /// extendDef - Extend the current definition as far as possible down the
185 /// dominator tree. Stop when meeting an existing def or when leaving the live
187 /// End points where VNI is no longer live are added to Kills.
188 /// @param Idx Starting point for the definition.
189 /// @param LocNo Location number to propagate.
190 /// @param LI Restrict liveness to where LI has the value VNI. May be null.
191 /// @param VNI When LI is not null, this is the value to restrict to.
192 /// @param Kills Append end points of VNI's live range to Kills.
193 /// @param LIS Live intervals analysis.
194 /// @param MDT Dominator tree.
195 void extendDef(SlotIndex Idx, unsigned LocNo,
196 LiveInterval *LI, const VNInfo *VNI,
197 SmallVectorImpl<SlotIndex> *Kills,
198 LiveIntervals &LIS, MachineDominatorTree &MDT);
200 /// addDefsFromCopies - The value in LI/LocNo may be copies to other
201 /// registers. Determine if any of the copies are available at the kill
202 /// points, and add defs if possible.
203 /// @param LI Scan for copies of the value in LI->reg.
204 /// @param LocNo Location number of LI->reg.
205 /// @param Kills Points where the range of LocNo could be extended.
206 /// @param NewDefs Append (Idx, LocNo) of inserted defs here.
207 void addDefsFromCopies(LiveInterval *LI, unsigned LocNo,
208 const SmallVectorImpl<SlotIndex> &Kills,
209 SmallVectorImpl<std::pair<SlotIndex, unsigned> > &NewDefs,
210 MachineRegisterInfo &MRI,
213 /// computeIntervals - Compute the live intervals of all locations after
214 /// collecting all their def points.
215 void computeIntervals(MachineRegisterInfo &MRI,
216 LiveIntervals &LIS, MachineDominatorTree &MDT);
218 /// renameRegister - Update locations to rewrite OldReg as NewReg:SubIdx.
219 void renameRegister(unsigned OldReg, unsigned NewReg, unsigned SubIdx,
220 const TargetRegisterInfo *TRI);
222 /// rewriteLocations - Rewrite virtual register locations according to the
223 /// provided virtual register map.
224 void rewriteLocations(VirtRegMap &VRM, const TargetRegisterInfo &TRI);
226 /// emitDebugVariables - Recreate DBG_VALUE instruction from data structures.
227 void emitDebugValues(VirtRegMap *VRM,
228 LiveIntervals &LIS, const TargetInstrInfo &TRI);
230 /// findDebugLoc - Return DebugLoc used for this DBG_VALUE instruction. A
231 /// variable may have more than one corresponding DBG_VALUE instructions.
232 /// Only first one needs DebugLoc to identify variable's lexical scope
234 DebugLoc findDebugLoc();
235 void print(raw_ostream&, const TargetRegisterInfo*);
239 /// LDVImpl - Implementation of the LiveDebugVariables pass.
242 LiveDebugVariables &pass;
243 LocMap::Allocator allocator;
246 MachineDominatorTree *MDT;
247 const TargetRegisterInfo *TRI;
249 /// userValues - All allocated UserValue instances.
250 SmallVector<UserValue*, 8> userValues;
252 /// Map virtual register to eq class leader.
253 typedef DenseMap<unsigned, UserValue*> VRMap;
254 VRMap virtRegToEqClass;
256 /// Map user variable to eq class leader.
257 typedef DenseMap<const MDNode *, UserValue*> UVMap;
260 /// getUserValue - Find or create a UserValue.
261 UserValue *getUserValue(const MDNode *Var, unsigned Offset, DebugLoc DL);
263 /// lookupVirtReg - Find the EC leader for VirtReg or null.
264 UserValue *lookupVirtReg(unsigned VirtReg);
266 /// handleDebugValue - Add DBG_VALUE instruction to our maps.
267 /// @param MI DBG_VALUE instruction
268 /// @param Idx Last valid SLotIndex before instruction.
269 /// @return True if the DBG_VALUE instruction should be deleted.
270 bool handleDebugValue(MachineInstr *MI, SlotIndex Idx);
272 /// collectDebugValues - Collect and erase all DBG_VALUE instructions, adding
273 /// a UserValue def for each instruction.
274 /// @param mf MachineFunction to be scanned.
275 /// @return True if any debug values were found.
276 bool collectDebugValues(MachineFunction &mf);
278 /// computeIntervals - Compute the live intervals of all user values after
279 /// collecting all their def points.
280 void computeIntervals();
283 LDVImpl(LiveDebugVariables *ps) : pass(*ps) {}
284 bool runOnMachineFunction(MachineFunction &mf);
286 /// clear - Relase all memory.
288 DeleteContainerPointers(userValues);
290 virtRegToEqClass.clear();
294 /// mapVirtReg - Map virtual register to an equivalence class.
295 void mapVirtReg(unsigned VirtReg, UserValue *EC);
297 /// renameRegister - Replace all references to OldReg wiht NewReg:SubIdx.
298 void renameRegister(unsigned OldReg, unsigned NewReg, unsigned SubIdx);
300 /// emitDebugVariables - Recreate DBG_VALUE instruction from data structures.
301 void emitDebugValues(VirtRegMap *VRM);
303 void print(raw_ostream&);
307 void UserValue::print(raw_ostream &OS, const TargetRegisterInfo *TRI) {
308 if (const MDString *MDS = dyn_cast<MDString>(variable->getOperand(2)))
309 OS << "!\"" << MDS->getString() << "\"\t";
312 for (LocMap::const_iterator I = locInts.begin(); I.valid(); ++I) {
313 OS << " [" << I.start() << ';' << I.stop() << "):";
314 if (I.value() == ~0u)
319 for (unsigned i = 0, e = locations.size(); i != e; ++i)
320 OS << " Loc" << i << '=' << locations[i];
324 void LDVImpl::print(raw_ostream &OS) {
325 OS << "********** DEBUG VARIABLES **********\n";
326 for (unsigned i = 0, e = userValues.size(); i != e; ++i)
327 userValues[i]->print(OS, TRI);
330 void UserValue::coalesceLocation(unsigned LocNo) {
331 unsigned KeepLoc = 0;
332 for (unsigned e = locations.size(); KeepLoc != e; ++KeepLoc) {
333 if (KeepLoc == LocNo)
335 if (locations[KeepLoc].isIdenticalTo(locations[LocNo]))
339 if (KeepLoc == locations.size())
342 // Keep the smaller location, erase the larger one.
343 unsigned EraseLoc = LocNo;
344 if (KeepLoc > EraseLoc)
345 std::swap(KeepLoc, EraseLoc);
346 locations.erase(locations.begin() + EraseLoc);
349 for (LocMap::iterator I = locInts.begin(); I.valid(); ++I) {
350 unsigned v = I.value();
352 I.setValue(KeepLoc); // Coalesce when possible.
353 else if (v > EraseLoc)
354 I.setValueUnchecked(v-1); // Avoid coalescing with untransformed values.
358 void UserValue::mapVirtRegs(LDVImpl *LDV) {
359 for (unsigned i = 0, e = locations.size(); i != e; ++i)
360 if (locations[i].isReg() &&
361 TargetRegisterInfo::isVirtualRegister(locations[i].getReg()))
362 LDV->mapVirtReg(locations[i].getReg(), this);
365 UserValue *LDVImpl::getUserValue(const MDNode *Var, unsigned Offset,
367 UserValue *&Leader = userVarMap[Var];
369 UserValue *UV = Leader->getLeader();
371 for (; UV; UV = UV->getNext())
372 if (UV->match(Var, Offset))
376 UserValue *UV = new UserValue(Var, Offset, DL, allocator);
377 userValues.push_back(UV);
378 Leader = UserValue::merge(Leader, UV);
382 void LDVImpl::mapVirtReg(unsigned VirtReg, UserValue *EC) {
383 assert(TargetRegisterInfo::isVirtualRegister(VirtReg) && "Only map VirtRegs");
384 UserValue *&Leader = virtRegToEqClass[VirtReg];
385 Leader = UserValue::merge(Leader, EC);
388 UserValue *LDVImpl::lookupVirtReg(unsigned VirtReg) {
389 if (UserValue *UV = virtRegToEqClass.lookup(VirtReg))
390 return UV->getLeader();
394 bool LDVImpl::handleDebugValue(MachineInstr *MI, SlotIndex Idx) {
395 // DBG_VALUE loc, offset, variable
396 if (MI->getNumOperands() != 3 ||
397 !MI->getOperand(1).isImm() || !MI->getOperand(2).isMetadata()) {
398 DEBUG(dbgs() << "Can't handle " << *MI);
402 // Get or create the UserValue for (variable,offset).
403 unsigned Offset = MI->getOperand(1).getImm();
404 const MDNode *Var = MI->getOperand(2).getMetadata();
405 UserValue *UV = getUserValue(Var, Offset, MI->getDebugLoc());
406 UV->addDef(Idx, MI->getOperand(0));
410 bool LDVImpl::collectDebugValues(MachineFunction &mf) {
411 bool Changed = false;
412 for (MachineFunction::iterator MFI = mf.begin(), MFE = mf.end(); MFI != MFE;
414 MachineBasicBlock *MBB = MFI;
415 for (MachineBasicBlock::iterator MBBI = MBB->begin(), MBBE = MBB->end();
417 if (!MBBI->isDebugValue()) {
421 // DBG_VALUE has no slot index, use the previous instruction instead.
422 SlotIndex Idx = MBBI == MBB->begin() ?
423 LIS->getMBBStartIdx(MBB) :
424 LIS->getInstructionIndex(llvm::prior(MBBI)).getDefIndex();
425 // Handle consecutive DBG_VALUE instructions with the same slot index.
427 if (handleDebugValue(MBBI, Idx)) {
428 MBBI = MBB->erase(MBBI);
432 } while (MBBI != MBBE && MBBI->isDebugValue());
438 void UserValue::extendDef(SlotIndex Idx, unsigned LocNo,
439 LiveInterval *LI, const VNInfo *VNI,
440 SmallVectorImpl<SlotIndex> *Kills,
441 LiveIntervals &LIS, MachineDominatorTree &MDT) {
442 SmallVector<SlotIndex, 16> Todo;
446 SlotIndex Start = Todo.pop_back_val();
447 MachineBasicBlock *MBB = LIS.getMBBFromIndex(Start);
448 SlotIndex Stop = LIS.getMBBEndIdx(MBB);
449 LocMap::iterator I = locInts.find(Start);
451 // Limit to VNI's live range.
454 LiveRange *Range = LI->getLiveRangeContaining(Start);
455 if (!Range || Range->valno != VNI) {
457 Kills->push_back(Start);
460 if (Range->end < Stop)
461 Stop = Range->end, ToEnd = false;
464 // There could already be a short def at Start.
465 if (I.valid() && I.start() <= Start) {
466 // Stop when meeting a different location or an already extended interval.
467 Start = Start.getNextSlot();
468 if (I.value() != LocNo || I.stop() != Start)
470 // This is a one-slot placeholder. Just skip it.
474 // Limited by the next def.
475 if (I.valid() && I.start() < Stop)
476 Stop = I.start(), ToEnd = false;
477 // Limited by VNI's live range.
478 else if (!ToEnd && Kills)
479 Kills->push_back(Stop);
484 I.insert(Start, Stop, LocNo);
486 // If we extended to the MBB end, propagate down the dominator tree.
489 const std::vector<MachineDomTreeNode*> &Children =
490 MDT.getNode(MBB)->getChildren();
491 for (unsigned i = 0, e = Children.size(); i != e; ++i)
492 Todo.push_back(LIS.getMBBStartIdx(Children[i]->getBlock()));
493 } while (!Todo.empty());
497 UserValue::addDefsFromCopies(LiveInterval *LI, unsigned LocNo,
498 const SmallVectorImpl<SlotIndex> &Kills,
499 SmallVectorImpl<std::pair<SlotIndex, unsigned> > &NewDefs,
500 MachineRegisterInfo &MRI, LiveIntervals &LIS) {
503 // Don't track copies from physregs, there are too many uses.
504 if (!TargetRegisterInfo::isVirtualRegister(LI->reg))
507 // Collect all the (vreg, valno) pairs that are copies of LI.
508 SmallVector<std::pair<LiveInterval*, const VNInfo*>, 8> CopyValues;
509 for (MachineRegisterInfo::use_nodbg_iterator
510 UI = MRI.use_nodbg_begin(LI->reg),
511 UE = MRI.use_nodbg_end(); UI != UE; ++UI) {
512 // Copies of the full value.
513 if (UI.getOperand().getSubReg() || !UI->isCopy())
515 MachineInstr *MI = &*UI;
516 unsigned DstReg = MI->getOperand(0).getReg();
518 // Is LocNo extended to reach this copy? If not, another def may be blocking
519 // it, or we are looking at a wrong value of LI.
520 SlotIndex Idx = LIS.getInstructionIndex(MI);
521 LocMap::iterator I = locInts.find(Idx.getUseIndex());
522 if (!I.valid() || I.value() != LocNo)
525 if (!LIS.hasInterval(DstReg))
527 LiveInterval *DstLI = &LIS.getInterval(DstReg);
528 const VNInfo *DstVNI = DstLI->getVNInfoAt(Idx.getDefIndex());
529 assert(DstVNI && DstVNI->def == Idx.getDefIndex() && "Bad copy value");
530 CopyValues.push_back(std::make_pair(DstLI, DstVNI));
533 if (CopyValues.empty())
536 DEBUG(dbgs() << "Got " << CopyValues.size() << " copies of " << *LI << '\n');
538 // Try to add defs of the copied values for each kill point.
539 for (unsigned i = 0, e = Kills.size(); i != e; ++i) {
540 SlotIndex Idx = Kills[i];
541 for (unsigned j = 0, e = CopyValues.size(); j != e; ++j) {
542 LiveInterval *DstLI = CopyValues[j].first;
543 const VNInfo *DstVNI = CopyValues[j].second;
544 if (DstLI->getVNInfoAt(Idx) != DstVNI)
546 // Check that there isn't already a def at Idx
547 LocMap::iterator I = locInts.find(Idx);
548 if (I.valid() && I.start() <= Idx)
550 DEBUG(dbgs() << "Kill at " << Idx << " covered by valno #"
551 << DstVNI->id << " in " << *DstLI << '\n');
552 MachineInstr *CopyMI = LIS.getInstructionFromIndex(DstVNI->def);
553 assert(CopyMI && CopyMI->isCopy() && "Bad copy value");
554 unsigned LocNo = getLocationNo(CopyMI->getOperand(0));
555 I.insert(Idx, Idx.getNextSlot(), LocNo);
556 NewDefs.push_back(std::make_pair(Idx, LocNo));
563 UserValue::computeIntervals(MachineRegisterInfo &MRI,
565 MachineDominatorTree &MDT) {
566 SmallVector<std::pair<SlotIndex, unsigned>, 16> Defs;
568 // Collect all defs to be extended (Skipping undefs).
569 for (LocMap::const_iterator I = locInts.begin(); I.valid(); ++I)
570 if (I.value() != ~0u)
571 Defs.push_back(std::make_pair(I.start(), I.value()));
573 // Extend all defs, and possibly add new ones along the way.
574 for (unsigned i = 0; i != Defs.size(); ++i) {
575 SlotIndex Idx = Defs[i].first;
576 unsigned LocNo = Defs[i].second;
577 const MachineOperand &Loc = locations[LocNo];
579 // Register locations are constrained to where the register value is live.
580 if (Loc.isReg() && LIS.hasInterval(Loc.getReg())) {
581 LiveInterval *LI = &LIS.getInterval(Loc.getReg());
582 const VNInfo *VNI = LI->getVNInfoAt(Idx);
583 SmallVector<SlotIndex, 16> Kills;
584 extendDef(Idx, LocNo, LI, VNI, &Kills, LIS, MDT);
585 addDefsFromCopies(LI, LocNo, Kills, Defs, MRI, LIS);
587 extendDef(Idx, LocNo, 0, 0, 0, LIS, MDT);
590 // Finally, erase all the undefs.
591 for (LocMap::iterator I = locInts.begin(); I.valid();)
592 if (I.value() == ~0u)
598 void LDVImpl::computeIntervals() {
599 for (unsigned i = 0, e = userValues.size(); i != e; ++i) {
600 userValues[i]->computeIntervals(MF->getRegInfo(), *LIS, *MDT);
601 userValues[i]->mapVirtRegs(this);
605 bool LDVImpl::runOnMachineFunction(MachineFunction &mf) {
607 LIS = &pass.getAnalysis<LiveIntervals>();
608 MDT = &pass.getAnalysis<MachineDominatorTree>();
609 TRI = mf.getTarget().getRegisterInfo();
611 DEBUG(dbgs() << "********** COMPUTING LIVE DEBUG VARIABLES: "
612 << ((Value*)mf.getFunction())->getName()
615 bool Changed = collectDebugValues(mf);
617 DEBUG(print(dbgs()));
621 bool LiveDebugVariables::runOnMachineFunction(MachineFunction &mf) {
625 pImpl = new LDVImpl(this);
626 return static_cast<LDVImpl*>(pImpl)->runOnMachineFunction(mf);
629 void LiveDebugVariables::releaseMemory() {
631 static_cast<LDVImpl*>(pImpl)->clear();
634 LiveDebugVariables::~LiveDebugVariables() {
636 delete static_cast<LDVImpl*>(pImpl);
640 renameRegister(unsigned OldReg, unsigned NewReg, unsigned SubIdx,
641 const TargetRegisterInfo *TRI) {
642 for (unsigned i = locations.size(); i; --i) {
643 unsigned LocNo = i - 1;
644 MachineOperand &Loc = locations[LocNo];
645 if (!Loc.isReg() || Loc.getReg() != OldReg)
647 if (TargetRegisterInfo::isPhysicalRegister(NewReg))
648 Loc.substPhysReg(NewReg, *TRI);
650 Loc.substVirtReg(NewReg, SubIdx, *TRI);
651 coalesceLocation(LocNo);
656 renameRegister(unsigned OldReg, unsigned NewReg, unsigned SubIdx) {
657 UserValue *UV = lookupVirtReg(OldReg);
661 if (TargetRegisterInfo::isVirtualRegister(NewReg))
662 mapVirtReg(NewReg, UV);
663 virtRegToEqClass.erase(OldReg);
666 UV->renameRegister(OldReg, NewReg, SubIdx, TRI);
671 void LiveDebugVariables::
672 renameRegister(unsigned OldReg, unsigned NewReg, unsigned SubIdx) {
674 static_cast<LDVImpl*>(pImpl)->renameRegister(OldReg, NewReg, SubIdx);
678 UserValue::rewriteLocations(VirtRegMap &VRM, const TargetRegisterInfo &TRI) {
679 // Iterate over locations in reverse makes it easier to handle coalescing.
680 for (unsigned i = locations.size(); i ; --i) {
681 unsigned LocNo = i-1;
682 MachineOperand &Loc = locations[LocNo];
683 // Only virtual registers are rewritten.
684 if (!Loc.isReg() || !Loc.getReg() ||
685 !TargetRegisterInfo::isVirtualRegister(Loc.getReg()))
687 unsigned VirtReg = Loc.getReg();
688 if (VRM.isAssignedReg(VirtReg) &&
689 TargetRegisterInfo::isPhysicalRegister(VRM.getPhys(VirtReg))) {
690 Loc.substPhysReg(VRM.getPhys(VirtReg), TRI);
691 } else if (VRM.getStackSlot(VirtReg) != VirtRegMap::NO_STACK_SLOT &&
692 VRM.isSpillSlotUsed(VRM.getStackSlot(VirtReg))) {
693 // FIXME: Translate SubIdx to a stackslot offset.
694 Loc = MachineOperand::CreateFI(VRM.getStackSlot(VirtReg));
699 coalesceLocation(LocNo);
701 DEBUG(print(dbgs(), &TRI));
704 /// findInsertLocation - Find an iterator for inserting a DBG_VALUE
706 static MachineBasicBlock::iterator
707 findInsertLocation(MachineBasicBlock *MBB, SlotIndex Idx,
708 LiveIntervals &LIS) {
709 SlotIndex Start = LIS.getMBBStartIdx(MBB);
710 Idx = Idx.getBaseIndex();
712 // Try to find an insert location by going backwards from Idx.
714 while (!(MI = LIS.getInstructionFromIndex(Idx))) {
715 // We've reached the beginning of MBB.
717 MachineBasicBlock::iterator I = MBB->SkipPHIsAndLabels(MBB->begin());
720 Idx = Idx.getPrevIndex();
723 // Don't insert anything after the first terminator, though.
724 return MI->getDesc().isTerminator() ? MBB->getFirstTerminator() :
725 llvm::next(MachineBasicBlock::iterator(MI));
728 DebugLoc UserValue::findDebugLoc() {
733 void UserValue::insertDebugValue(MachineBasicBlock *MBB, SlotIndex Idx,
736 const TargetInstrInfo &TII) {
737 MachineBasicBlock::iterator I = findInsertLocation(MBB, Idx, LIS);
738 MachineOperand &Loc = locations[LocNo];
740 // Frame index locations may require a target callback.
742 MachineInstr *MI = TII.emitFrameIndexDebugValue(*MBB->getParent(),
743 Loc.getIndex(), offset, variable,
750 // This is not a frame index, or the target is happy with a standard FI.
751 BuildMI(*MBB, I, findDebugLoc(), TII.get(TargetOpcode::DBG_VALUE))
752 .addOperand(Loc).addImm(offset).addMetadata(variable);
755 void UserValue::insertDebugKill(MachineBasicBlock *MBB, SlotIndex Idx,
756 LiveIntervals &LIS, const TargetInstrInfo &TII) {
757 MachineBasicBlock::iterator I = findInsertLocation(MBB, Idx, LIS);
758 BuildMI(*MBB, I, findDebugLoc(), TII.get(TargetOpcode::DBG_VALUE)).addReg(0)
759 .addImm(offset).addMetadata(variable);
762 void UserValue::emitDebugValues(VirtRegMap *VRM, LiveIntervals &LIS,
763 const TargetInstrInfo &TII) {
764 MachineFunction::iterator MFEnd = VRM->getMachineFunction().end();
766 for (LocMap::const_iterator I = locInts.begin(); I.valid();) {
767 SlotIndex Start = I.start();
768 SlotIndex Stop = I.stop();
769 unsigned LocNo = I.value();
770 DEBUG(dbgs() << "\t[" << Start << ';' << Stop << "):" << LocNo);
771 MachineFunction::iterator MBB = LIS.getMBBFromIndex(Start);
772 SlotIndex MBBEnd = LIS.getMBBEndIdx(MBB);
774 DEBUG(dbgs() << " BB#" << MBB->getNumber() << '-' << MBBEnd);
775 insertDebugValue(MBB, Start, LocNo, LIS, TII);
777 // This interval may span multiple basic blocks.
778 // Insert a DBG_VALUE into each one.
779 while(Stop > MBBEnd) {
780 // Move to the next block.
784 MBBEnd = LIS.getMBBEndIdx(MBB);
785 DEBUG(dbgs() << " BB#" << MBB->getNumber() << '-' << MBBEnd);
786 insertDebugValue(MBB, Start, LocNo, LIS, TII);
788 DEBUG(dbgs() << '\n');
795 // The current interval ends before MBB.
796 // Insert a kill if there is a gap.
797 if (!I.valid() || I.start() > Stop)
798 insertDebugKill(MBB, Stop, LIS, TII);
802 void LDVImpl::emitDebugValues(VirtRegMap *VRM) {
803 DEBUG(dbgs() << "********** EMITTING LIVE DEBUG VARIABLES **********\n");
804 const TargetInstrInfo *TII = MF->getTarget().getInstrInfo();
805 for (unsigned i = 0, e = userValues.size(); i != e; ++i) {
806 userValues[i]->rewriteLocations(*VRM, *TRI);
807 userValues[i]->emitDebugValues(VRM, *LIS, *TII);
811 void LiveDebugVariables::emitDebugValues(VirtRegMap *VRM) {
813 static_cast<LDVImpl*>(pImpl)->emitDebugValues(VRM);
818 void LiveDebugVariables::dump() {
820 static_cast<LDVImpl*>(pImpl)->print(dbgs());