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);
105 /// UserValue - Create a new UserValue.
106 UserValue(const MDNode *var, unsigned o, DebugLoc L,
107 LocMap::Allocator &alloc)
108 : variable(var), offset(o), dl(L), leader(this), next(0), locInts(alloc)
111 /// getLeader - Get the leader of this value's equivalence class.
112 UserValue *getLeader() {
113 UserValue *l = leader;
114 while (l != l->leader)
119 /// getNext - Return the next UserValue in the equivalence class.
120 UserValue *getNext() const { return next; }
122 /// match - Does this UserValue match the aprameters?
123 bool match(const MDNode *Var, unsigned Offset) const {
124 return Var == variable && Offset == offset;
127 /// merge - Merge equivalence classes.
128 static UserValue *merge(UserValue *L1, UserValue *L2) {
129 L2 = L2->getLeader();
132 L1 = L1->getLeader();
135 // Splice L2 before L1's members.
138 End->leader = L1, End = End->next;
140 End->next = L1->next;
145 /// getLocationNo - Return the location number that matches Loc.
146 unsigned getLocationNo(const MachineOperand &LocMO) {
148 if (LocMO.getReg() == 0)
150 // For register locations we dont care about use/def and other flags.
151 for (unsigned i = 0, e = locations.size(); i != e; ++i)
152 if (locations[i].isReg() &&
153 locations[i].getReg() == LocMO.getReg() &&
154 locations[i].getSubReg() == LocMO.getSubReg())
157 for (unsigned i = 0, e = locations.size(); i != e; ++i)
158 if (LocMO.isIdenticalTo(locations[i]))
160 locations.push_back(LocMO);
161 // We are storing a MachineOperand outside a MachineInstr.
162 locations.back().clearParent();
163 // Don't store def operands.
164 if (locations.back().isReg())
165 locations.back().setIsUse();
166 return locations.size() - 1;
169 /// mapVirtRegs - Ensure that all virtual register locations are mapped.
170 void mapVirtRegs(LDVImpl *LDV);
172 /// addDef - Add a definition point to this value.
173 void addDef(SlotIndex Idx, const MachineOperand &LocMO) {
174 // Add a singular (Idx,Idx) -> Loc mapping.
175 LocMap::iterator I = locInts.find(Idx);
176 if (!I.valid() || I.start() != Idx)
177 I.insert(Idx, Idx.getNextSlot(), getLocationNo(LocMO));
180 /// extendDef - Extend the current definition as far as possible down the
181 /// dominator tree. Stop when meeting an existing def or when leaving the live
183 /// End points where VNI is no longer live are added to Kills.
184 /// @param Idx Starting point for the definition.
185 /// @param LocNo Location number to propagate.
186 /// @param LI Restrict liveness to where LI has the value VNI. May be null.
187 /// @param VNI When LI is not null, this is the value to restrict to.
188 /// @param Kills Append end points of VNI's live range to Kills.
189 /// @param LIS Live intervals analysis.
190 /// @param MDT Dominator tree.
191 void extendDef(SlotIndex Idx, unsigned LocNo,
192 LiveInterval *LI, const VNInfo *VNI,
193 SmallVectorImpl<SlotIndex> *Kills,
194 LiveIntervals &LIS, MachineDominatorTree &MDT);
196 /// addDefsFromCopies - The value in LI/LocNo may be copies to other
197 /// registers. Determine if any of the copies are available at the kill
198 /// points, and add defs if possible.
199 /// @param LI Scan for copies of the value in LI->reg.
200 /// @param LocNo Location number of LI->reg.
201 /// @param Kills Points where the range of LocNo could be extended.
202 /// @param NewDefs Append (Idx, LocNo) of inserted defs here.
203 void addDefsFromCopies(LiveInterval *LI, unsigned LocNo,
204 const SmallVectorImpl<SlotIndex> &Kills,
205 SmallVectorImpl<std::pair<SlotIndex, unsigned> > &NewDefs,
206 MachineRegisterInfo &MRI,
209 /// computeIntervals - Compute the live intervals of all locations after
210 /// collecting all their def points.
211 void computeIntervals(MachineRegisterInfo &MRI,
212 LiveIntervals &LIS, MachineDominatorTree &MDT);
214 /// renameRegister - Update locations to rewrite OldReg as NewReg:SubIdx.
215 void renameRegister(unsigned OldReg, unsigned NewReg, unsigned SubIdx,
216 const TargetRegisterInfo *TRI);
218 /// rewriteLocations - Rewrite virtual register locations according to the
219 /// provided virtual register map.
220 void rewriteLocations(VirtRegMap &VRM, const TargetRegisterInfo &TRI);
222 /// emitDebugVariables - Recreate DBG_VALUE instruction from data structures.
223 void emitDebugValues(VirtRegMap *VRM,
224 LiveIntervals &LIS, const TargetInstrInfo &TRI);
226 /// findDebugLoc - Return DebugLoc used for this DBG_VALUE instruction. A
227 /// variable may have more than one corresponding DBG_VALUE instructions.
228 /// Only first one needs DebugLoc to identify variable's lexical scope
230 DebugLoc findDebugLoc();
231 void print(raw_ostream&, const TargetMachine*);
235 /// LDVImpl - Implementation of the LiveDebugVariables pass.
238 LiveDebugVariables &pass;
239 LocMap::Allocator allocator;
242 MachineDominatorTree *MDT;
243 const TargetRegisterInfo *TRI;
245 /// userValues - All allocated UserValue instances.
246 SmallVector<UserValue*, 8> userValues;
248 /// Map virtual register to eq class leader.
249 typedef DenseMap<unsigned, UserValue*> VRMap;
250 VRMap virtRegToEqClass;
252 /// Map user variable to eq class leader.
253 typedef DenseMap<const MDNode *, UserValue*> UVMap;
256 /// getUserValue - Find or create a UserValue.
257 UserValue *getUserValue(const MDNode *Var, unsigned Offset, DebugLoc DL);
259 /// lookupVirtReg - Find the EC leader for VirtReg or null.
260 UserValue *lookupVirtReg(unsigned VirtReg);
262 /// handleDebugValue - Add DBG_VALUE instruction to our maps.
263 /// @param MI DBG_VALUE instruction
264 /// @param Idx Last valid SLotIndex before instruction.
265 /// @return True if the DBG_VALUE instruction should be deleted.
266 bool handleDebugValue(MachineInstr *MI, SlotIndex Idx);
268 /// collectDebugValues - Collect and erase all DBG_VALUE instructions, adding
269 /// a UserValue def for each instruction.
270 /// @param mf MachineFunction to be scanned.
271 /// @return True if any debug values were found.
272 bool collectDebugValues(MachineFunction &mf);
274 /// computeIntervals - Compute the live intervals of all user values after
275 /// collecting all their def points.
276 void computeIntervals();
279 LDVImpl(LiveDebugVariables *ps) : pass(*ps) {}
280 bool runOnMachineFunction(MachineFunction &mf);
282 /// clear - Relase all memory.
284 DeleteContainerPointers(userValues);
286 virtRegToEqClass.clear();
290 /// mapVirtReg - Map virtual register to an equivalence class.
291 void mapVirtReg(unsigned VirtReg, UserValue *EC);
293 /// renameRegister - Replace all references to OldReg with NewReg:SubIdx.
294 void renameRegister(unsigned OldReg, unsigned NewReg, unsigned SubIdx);
296 /// emitDebugVariables - Recreate DBG_VALUE instruction from data structures.
297 void emitDebugValues(VirtRegMap *VRM);
299 void print(raw_ostream&);
303 void UserValue::print(raw_ostream &OS, const TargetMachine *TM) {
304 if (const MDString *MDS = dyn_cast<MDString>(variable->getOperand(2)))
305 OS << "!\"" << MDS->getString() << "\"\t";
308 for (LocMap::const_iterator I = locInts.begin(); I.valid(); ++I) {
309 OS << " [" << I.start() << ';' << I.stop() << "):";
310 if (I.value() == ~0u)
315 for (unsigned i = 0, e = locations.size(); i != e; ++i) {
316 OS << " Loc" << i << '=';
317 locations[i].print(OS, TM);
322 void LDVImpl::print(raw_ostream &OS) {
323 OS << "********** DEBUG VARIABLES **********\n";
324 for (unsigned i = 0, e = userValues.size(); i != e; ++i)
325 userValues[i]->print(OS, &MF->getTarget());
328 void UserValue::coalesceLocation(unsigned LocNo) {
329 unsigned KeepLoc = 0;
330 for (unsigned e = locations.size(); KeepLoc != e; ++KeepLoc) {
331 if (KeepLoc == LocNo)
333 if (locations[KeepLoc].isIdenticalTo(locations[LocNo]))
337 if (KeepLoc == locations.size())
340 // Keep the smaller location, erase the larger one.
341 unsigned EraseLoc = LocNo;
342 if (KeepLoc > EraseLoc)
343 std::swap(KeepLoc, EraseLoc);
344 locations.erase(locations.begin() + EraseLoc);
347 for (LocMap::iterator I = locInts.begin(); I.valid(); ++I) {
348 unsigned v = I.value();
350 I.setValue(KeepLoc); // Coalesce when possible.
351 else if (v > EraseLoc)
352 I.setValueUnchecked(v-1); // Avoid coalescing with untransformed values.
356 void UserValue::mapVirtRegs(LDVImpl *LDV) {
357 for (unsigned i = 0, e = locations.size(); i != e; ++i)
358 if (locations[i].isReg() &&
359 TargetRegisterInfo::isVirtualRegister(locations[i].getReg()))
360 LDV->mapVirtReg(locations[i].getReg(), this);
363 UserValue *LDVImpl::getUserValue(const MDNode *Var, unsigned Offset,
365 UserValue *&Leader = userVarMap[Var];
367 UserValue *UV = Leader->getLeader();
369 for (; UV; UV = UV->getNext())
370 if (UV->match(Var, Offset))
374 UserValue *UV = new UserValue(Var, Offset, DL, allocator);
375 userValues.push_back(UV);
376 Leader = UserValue::merge(Leader, UV);
380 void LDVImpl::mapVirtReg(unsigned VirtReg, UserValue *EC) {
381 assert(TargetRegisterInfo::isVirtualRegister(VirtReg) && "Only map VirtRegs");
382 UserValue *&Leader = virtRegToEqClass[VirtReg];
383 Leader = UserValue::merge(Leader, EC);
386 UserValue *LDVImpl::lookupVirtReg(unsigned VirtReg) {
387 if (UserValue *UV = virtRegToEqClass.lookup(VirtReg))
388 return UV->getLeader();
392 bool LDVImpl::handleDebugValue(MachineInstr *MI, SlotIndex Idx) {
393 // DBG_VALUE loc, offset, variable
394 if (MI->getNumOperands() != 3 ||
395 !MI->getOperand(1).isImm() || !MI->getOperand(2).isMetadata()) {
396 DEBUG(dbgs() << "Can't handle " << *MI);
400 // Get or create the UserValue for (variable,offset).
401 unsigned Offset = MI->getOperand(1).getImm();
402 const MDNode *Var = MI->getOperand(2).getMetadata();
403 UserValue *UV = getUserValue(Var, Offset, MI->getDebugLoc());
404 UV->addDef(Idx, MI->getOperand(0));
408 bool LDVImpl::collectDebugValues(MachineFunction &mf) {
409 bool Changed = false;
410 for (MachineFunction::iterator MFI = mf.begin(), MFE = mf.end(); MFI != MFE;
412 MachineBasicBlock *MBB = MFI;
413 for (MachineBasicBlock::iterator MBBI = MBB->begin(), MBBE = MBB->end();
415 if (!MBBI->isDebugValue()) {
419 // DBG_VALUE has no slot index, use the previous instruction instead.
420 SlotIndex Idx = MBBI == MBB->begin() ?
421 LIS->getMBBStartIdx(MBB) :
422 LIS->getInstructionIndex(llvm::prior(MBBI)).getDefIndex();
423 // Handle consecutive DBG_VALUE instructions with the same slot index.
425 if (handleDebugValue(MBBI, Idx)) {
426 MBBI = MBB->erase(MBBI);
430 } while (MBBI != MBBE && MBBI->isDebugValue());
436 void UserValue::extendDef(SlotIndex Idx, unsigned LocNo,
437 LiveInterval *LI, const VNInfo *VNI,
438 SmallVectorImpl<SlotIndex> *Kills,
439 LiveIntervals &LIS, MachineDominatorTree &MDT) {
440 SmallVector<SlotIndex, 16> Todo;
444 SlotIndex Start = Todo.pop_back_val();
445 MachineBasicBlock *MBB = LIS.getMBBFromIndex(Start);
446 SlotIndex Stop = LIS.getMBBEndIdx(MBB);
447 LocMap::iterator I = locInts.find(Start);
449 // Limit to VNI's live range.
452 LiveRange *Range = LI->getLiveRangeContaining(Start);
453 if (!Range || Range->valno != VNI) {
455 Kills->push_back(Start);
458 if (Range->end < Stop)
459 Stop = Range->end, ToEnd = false;
462 // There could already be a short def at Start.
463 if (I.valid() && I.start() <= Start) {
464 // Stop when meeting a different location or an already extended interval.
465 Start = Start.getNextSlot();
466 if (I.value() != LocNo || I.stop() != Start)
468 // This is a one-slot placeholder. Just skip it.
472 // Limited by the next def.
473 if (I.valid() && I.start() < Stop)
474 Stop = I.start(), ToEnd = false;
475 // Limited by VNI's live range.
476 else if (!ToEnd && Kills)
477 Kills->push_back(Stop);
482 I.insert(Start, Stop, LocNo);
484 // If we extended to the MBB end, propagate down the dominator tree.
487 const std::vector<MachineDomTreeNode*> &Children =
488 MDT.getNode(MBB)->getChildren();
489 for (unsigned i = 0, e = Children.size(); i != e; ++i)
490 Todo.push_back(LIS.getMBBStartIdx(Children[i]->getBlock()));
491 } while (!Todo.empty());
495 UserValue::addDefsFromCopies(LiveInterval *LI, unsigned LocNo,
496 const SmallVectorImpl<SlotIndex> &Kills,
497 SmallVectorImpl<std::pair<SlotIndex, unsigned> > &NewDefs,
498 MachineRegisterInfo &MRI, LiveIntervals &LIS) {
501 // Don't track copies from physregs, there are too many uses.
502 if (!TargetRegisterInfo::isVirtualRegister(LI->reg))
505 // Collect all the (vreg, valno) pairs that are copies of LI.
506 SmallVector<std::pair<LiveInterval*, const VNInfo*>, 8> CopyValues;
507 for (MachineRegisterInfo::use_nodbg_iterator
508 UI = MRI.use_nodbg_begin(LI->reg),
509 UE = MRI.use_nodbg_end(); UI != UE; ++UI) {
510 // Copies of the full value.
511 if (UI.getOperand().getSubReg() || !UI->isCopy())
513 MachineInstr *MI = &*UI;
514 unsigned DstReg = MI->getOperand(0).getReg();
516 // Don't follow copies to physregs. These are usually setting up call
517 // arguments, and the argument registers are always call clobbered. We are
518 // better off in the source register which could be a callee-saved register,
519 // or it could be spilled.
520 if (!TargetRegisterInfo::isVirtualRegister(DstReg))
523 // Is LocNo extended to reach this copy? If not, another def may be blocking
524 // it, or we are looking at a wrong value of LI.
525 SlotIndex Idx = LIS.getInstructionIndex(MI);
526 LocMap::iterator I = locInts.find(Idx.getUseIndex());
527 if (!I.valid() || I.value() != LocNo)
530 if (!LIS.hasInterval(DstReg))
532 LiveInterval *DstLI = &LIS.getInterval(DstReg);
533 const VNInfo *DstVNI = DstLI->getVNInfoAt(Idx.getDefIndex());
534 assert(DstVNI && DstVNI->def == Idx.getDefIndex() && "Bad copy value");
535 CopyValues.push_back(std::make_pair(DstLI, DstVNI));
538 if (CopyValues.empty())
541 DEBUG(dbgs() << "Got " << CopyValues.size() << " copies of " << *LI << '\n');
543 // Try to add defs of the copied values for each kill point.
544 for (unsigned i = 0, e = Kills.size(); i != e; ++i) {
545 SlotIndex Idx = Kills[i];
546 for (unsigned j = 0, e = CopyValues.size(); j != e; ++j) {
547 LiveInterval *DstLI = CopyValues[j].first;
548 const VNInfo *DstVNI = CopyValues[j].second;
549 if (DstLI->getVNInfoAt(Idx) != DstVNI)
551 // Check that there isn't already a def at Idx
552 LocMap::iterator I = locInts.find(Idx);
553 if (I.valid() && I.start() <= Idx)
555 DEBUG(dbgs() << "Kill at " << Idx << " covered by valno #"
556 << DstVNI->id << " in " << *DstLI << '\n');
557 MachineInstr *CopyMI = LIS.getInstructionFromIndex(DstVNI->def);
558 assert(CopyMI && CopyMI->isCopy() && "Bad copy value");
559 unsigned LocNo = getLocationNo(CopyMI->getOperand(0));
560 I.insert(Idx, Idx.getNextSlot(), LocNo);
561 NewDefs.push_back(std::make_pair(Idx, LocNo));
568 UserValue::computeIntervals(MachineRegisterInfo &MRI,
570 MachineDominatorTree &MDT) {
571 SmallVector<std::pair<SlotIndex, unsigned>, 16> Defs;
573 // Collect all defs to be extended (Skipping undefs).
574 for (LocMap::const_iterator I = locInts.begin(); I.valid(); ++I)
575 if (I.value() != ~0u)
576 Defs.push_back(std::make_pair(I.start(), I.value()));
578 // Extend all defs, and possibly add new ones along the way.
579 for (unsigned i = 0; i != Defs.size(); ++i) {
580 SlotIndex Idx = Defs[i].first;
581 unsigned LocNo = Defs[i].second;
582 const MachineOperand &Loc = locations[LocNo];
584 // Register locations are constrained to where the register value is live.
585 if (Loc.isReg() && LIS.hasInterval(Loc.getReg())) {
586 LiveInterval *LI = &LIS.getInterval(Loc.getReg());
587 const VNInfo *VNI = LI->getVNInfoAt(Idx);
588 SmallVector<SlotIndex, 16> Kills;
589 extendDef(Idx, LocNo, LI, VNI, &Kills, LIS, MDT);
590 addDefsFromCopies(LI, LocNo, Kills, Defs, MRI, LIS);
592 extendDef(Idx, LocNo, 0, 0, 0, LIS, MDT);
595 // Finally, erase all the undefs.
596 for (LocMap::iterator I = locInts.begin(); I.valid();)
597 if (I.value() == ~0u)
603 void LDVImpl::computeIntervals() {
604 for (unsigned i = 0, e = userValues.size(); i != e; ++i) {
605 userValues[i]->computeIntervals(MF->getRegInfo(), *LIS, *MDT);
606 userValues[i]->mapVirtRegs(this);
610 bool LDVImpl::runOnMachineFunction(MachineFunction &mf) {
612 LIS = &pass.getAnalysis<LiveIntervals>();
613 MDT = &pass.getAnalysis<MachineDominatorTree>();
614 TRI = mf.getTarget().getRegisterInfo();
616 DEBUG(dbgs() << "********** COMPUTING LIVE DEBUG VARIABLES: "
617 << ((Value*)mf.getFunction())->getName()
620 bool Changed = collectDebugValues(mf);
622 DEBUG(print(dbgs()));
626 bool LiveDebugVariables::runOnMachineFunction(MachineFunction &mf) {
630 pImpl = new LDVImpl(this);
631 return static_cast<LDVImpl*>(pImpl)->runOnMachineFunction(mf);
634 void LiveDebugVariables::releaseMemory() {
636 static_cast<LDVImpl*>(pImpl)->clear();
639 LiveDebugVariables::~LiveDebugVariables() {
641 delete static_cast<LDVImpl*>(pImpl);
645 renameRegister(unsigned OldReg, unsigned NewReg, unsigned SubIdx,
646 const TargetRegisterInfo *TRI) {
647 for (unsigned i = locations.size(); i; --i) {
648 unsigned LocNo = i - 1;
649 MachineOperand &Loc = locations[LocNo];
650 if (!Loc.isReg() || Loc.getReg() != OldReg)
652 if (TargetRegisterInfo::isPhysicalRegister(NewReg))
653 Loc.substPhysReg(NewReg, *TRI);
655 Loc.substVirtReg(NewReg, SubIdx, *TRI);
656 coalesceLocation(LocNo);
661 renameRegister(unsigned OldReg, unsigned NewReg, unsigned SubIdx) {
662 UserValue *UV = lookupVirtReg(OldReg);
666 if (TargetRegisterInfo::isVirtualRegister(NewReg))
667 mapVirtReg(NewReg, UV);
668 virtRegToEqClass.erase(OldReg);
671 UV->renameRegister(OldReg, NewReg, SubIdx, TRI);
676 void LiveDebugVariables::
677 renameRegister(unsigned OldReg, unsigned NewReg, unsigned SubIdx) {
679 static_cast<LDVImpl*>(pImpl)->renameRegister(OldReg, NewReg, SubIdx);
683 UserValue::rewriteLocations(VirtRegMap &VRM, const TargetRegisterInfo &TRI) {
684 // Iterate over locations in reverse makes it easier to handle coalescing.
685 for (unsigned i = locations.size(); i ; --i) {
686 unsigned LocNo = i-1;
687 MachineOperand &Loc = locations[LocNo];
688 // Only virtual registers are rewritten.
689 if (!Loc.isReg() || !Loc.getReg() ||
690 !TargetRegisterInfo::isVirtualRegister(Loc.getReg()))
692 unsigned VirtReg = Loc.getReg();
693 if (VRM.isAssignedReg(VirtReg) &&
694 TargetRegisterInfo::isPhysicalRegister(VRM.getPhys(VirtReg))) {
695 Loc.substPhysReg(VRM.getPhys(VirtReg), TRI);
696 } else if (VRM.getStackSlot(VirtReg) != VirtRegMap::NO_STACK_SLOT &&
697 VRM.isSpillSlotUsed(VRM.getStackSlot(VirtReg))) {
698 // FIXME: Translate SubIdx to a stackslot offset.
699 Loc = MachineOperand::CreateFI(VRM.getStackSlot(VirtReg));
704 coalesceLocation(LocNo);
708 /// findInsertLocation - Find an iterator for inserting a DBG_VALUE
710 static MachineBasicBlock::iterator
711 findInsertLocation(MachineBasicBlock *MBB, SlotIndex Idx,
712 LiveIntervals &LIS) {
713 SlotIndex Start = LIS.getMBBStartIdx(MBB);
714 Idx = Idx.getBaseIndex();
716 // Try to find an insert location by going backwards from Idx.
718 while (!(MI = LIS.getInstructionFromIndex(Idx))) {
719 // We've reached the beginning of MBB.
721 MachineBasicBlock::iterator I = MBB->SkipPHIsAndLabels(MBB->begin());
724 Idx = Idx.getPrevIndex();
727 // Don't insert anything after the first terminator, though.
728 return MI->getDesc().isTerminator() ? MBB->getFirstTerminator() :
729 llvm::next(MachineBasicBlock::iterator(MI));
732 DebugLoc UserValue::findDebugLoc() {
737 void UserValue::insertDebugValue(MachineBasicBlock *MBB, SlotIndex Idx,
740 const TargetInstrInfo &TII) {
741 MachineBasicBlock::iterator I = findInsertLocation(MBB, Idx, LIS);
742 MachineOperand &Loc = locations[LocNo];
744 // Frame index locations may require a target callback.
746 MachineInstr *MI = TII.emitFrameIndexDebugValue(*MBB->getParent(),
747 Loc.getIndex(), offset, variable,
754 // This is not a frame index, or the target is happy with a standard FI.
755 BuildMI(*MBB, I, findDebugLoc(), TII.get(TargetOpcode::DBG_VALUE))
756 .addOperand(Loc).addImm(offset).addMetadata(variable);
759 void UserValue::emitDebugValues(VirtRegMap *VRM, LiveIntervals &LIS,
760 const TargetInstrInfo &TII) {
761 MachineFunction::iterator MFEnd = VRM->getMachineFunction().end();
763 for (LocMap::const_iterator I = locInts.begin(); I.valid();) {
764 SlotIndex Start = I.start();
765 SlotIndex Stop = I.stop();
766 unsigned LocNo = I.value();
767 DEBUG(dbgs() << "\t[" << Start << ';' << Stop << "):" << LocNo);
768 MachineFunction::iterator MBB = LIS.getMBBFromIndex(Start);
769 SlotIndex MBBEnd = LIS.getMBBEndIdx(MBB);
771 DEBUG(dbgs() << " BB#" << MBB->getNumber() << '-' << MBBEnd);
772 insertDebugValue(MBB, Start, LocNo, LIS, TII);
774 // This interval may span multiple basic blocks.
775 // Insert a DBG_VALUE into each one.
776 while(Stop > MBBEnd) {
777 // Move to the next block.
781 MBBEnd = LIS.getMBBEndIdx(MBB);
782 DEBUG(dbgs() << " BB#" << MBB->getNumber() << '-' << MBBEnd);
783 insertDebugValue(MBB, Start, LocNo, LIS, TII);
785 DEBUG(dbgs() << '\n');
793 void LDVImpl::emitDebugValues(VirtRegMap *VRM) {
794 DEBUG(dbgs() << "********** EMITTING LIVE DEBUG VARIABLES **********\n");
795 const TargetInstrInfo *TII = MF->getTarget().getInstrInfo();
796 for (unsigned i = 0, e = userValues.size(); i != e; ++i) {
797 userValues[i]->rewriteLocations(*VRM, *TRI);
798 userValues[i]->emitDebugValues(VRM, *LIS, *TII);
802 void LiveDebugVariables::emitDebugValues(VirtRegMap *VRM) {
804 static_cast<LDVImpl*>(pImpl)->emitDebugValues(VRM);
809 void LiveDebugVariables::dump() {
811 static_cast<LDVImpl*>(pImpl)->print(dbgs());