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 /// splitLocation - Replace OldLocNo ranges with NewRegs ranges where NewRegs
105 /// is live. Returns true if any changes were made.
106 bool splitLocation(unsigned OldLocNo
, ArrayRef
<LiveInterval
*> NewRegs
);
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 parameters?
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 /// splitRegister - Replace OldReg ranges with NewRegs ranges where NewRegs is
223 /// live. Returns true if any changes were made.
224 bool splitRegister(unsigned OldLocNo
, ArrayRef
<LiveInterval
*> NewRegs
);
226 /// rewriteLocations - Rewrite virtual register locations according to the
227 /// provided virtual register map.
228 void rewriteLocations(VirtRegMap
&VRM
, const TargetRegisterInfo
&TRI
);
230 /// emitDebugVariables - Recreate DBG_VALUE instruction from data structures.
231 void emitDebugValues(VirtRegMap
*VRM
,
232 LiveIntervals
&LIS
, const TargetInstrInfo
&TRI
);
234 /// findDebugLoc - Return DebugLoc used for this DBG_VALUE instruction. A
235 /// variable may have more than one corresponding DBG_VALUE instructions.
236 /// Only first one needs DebugLoc to identify variable's lexical scope
238 DebugLoc
findDebugLoc();
239 void print(raw_ostream
&, const TargetMachine
*);
243 /// LDVImpl - Implementation of the LiveDebugVariables pass.
246 LiveDebugVariables
&pass
;
247 LocMap::Allocator allocator
;
250 MachineDominatorTree
*MDT
;
251 const TargetRegisterInfo
*TRI
;
253 /// userValues - All allocated UserValue instances.
254 SmallVector
<UserValue
*, 8> userValues
;
256 /// Map virtual register to eq class leader.
257 typedef DenseMap
<unsigned, UserValue
*> VRMap
;
258 VRMap virtRegToEqClass
;
260 /// Map user variable to eq class leader.
261 typedef DenseMap
<const MDNode
*, UserValue
*> UVMap
;
264 /// getUserValue - Find or create a UserValue.
265 UserValue
*getUserValue(const MDNode
*Var
, unsigned Offset
, DebugLoc DL
);
267 /// lookupVirtReg - Find the EC leader for VirtReg or null.
268 UserValue
*lookupVirtReg(unsigned VirtReg
);
270 /// handleDebugValue - Add DBG_VALUE instruction to our maps.
271 /// @param MI DBG_VALUE instruction
272 /// @param Idx Last valid SLotIndex before instruction.
273 /// @return True if the DBG_VALUE instruction should be deleted.
274 bool handleDebugValue(MachineInstr
*MI
, SlotIndex Idx
);
276 /// collectDebugValues - Collect and erase all DBG_VALUE instructions, adding
277 /// a UserValue def for each instruction.
278 /// @param mf MachineFunction to be scanned.
279 /// @return True if any debug values were found.
280 bool collectDebugValues(MachineFunction
&mf
);
282 /// computeIntervals - Compute the live intervals of all user values after
283 /// collecting all their def points.
284 void computeIntervals();
287 LDVImpl(LiveDebugVariables
*ps
) : pass(*ps
) {}
288 bool runOnMachineFunction(MachineFunction
&mf
);
290 /// clear - Relase all memory.
292 DeleteContainerPointers(userValues
);
294 virtRegToEqClass
.clear();
298 /// mapVirtReg - Map virtual register to an equivalence class.
299 void mapVirtReg(unsigned VirtReg
, UserValue
*EC
);
301 /// renameRegister - Replace all references to OldReg with NewReg:SubIdx.
302 void renameRegister(unsigned OldReg
, unsigned NewReg
, unsigned SubIdx
);
304 /// splitRegister - Replace all references to OldReg with NewRegs.
305 void splitRegister(unsigned OldReg
, ArrayRef
<LiveInterval
*> NewRegs
);
307 /// emitDebugVariables - Recreate DBG_VALUE instruction from data structures.
308 void emitDebugValues(VirtRegMap
*VRM
);
310 void print(raw_ostream
&);
314 void UserValue::print(raw_ostream
&OS
, const TargetMachine
*TM
) {
315 if (const MDString
*MDS
= dyn_cast
<MDString
>(variable
->getOperand(2)))
316 OS
<< "!\"" << MDS
->getString() << "\"\t";
319 for (LocMap::const_iterator I
= locInts
.begin(); I
.valid(); ++I
) {
320 OS
<< " [" << I
.start() << ';' << I
.stop() << "):";
321 if (I
.value() == ~0u)
326 for (unsigned i
= 0, e
= locations
.size(); i
!= e
; ++i
) {
327 OS
<< " Loc" << i
<< '=';
328 locations
[i
].print(OS
, TM
);
333 void LDVImpl::print(raw_ostream
&OS
) {
334 OS
<< "********** DEBUG VARIABLES **********\n";
335 for (unsigned i
= 0, e
= userValues
.size(); i
!= e
; ++i
)
336 userValues
[i
]->print(OS
, &MF
->getTarget());
339 void UserValue::coalesceLocation(unsigned LocNo
) {
340 unsigned KeepLoc
= 0;
341 for (unsigned e
= locations
.size(); KeepLoc
!= e
; ++KeepLoc
) {
342 if (KeepLoc
== LocNo
)
344 if (locations
[KeepLoc
].isIdenticalTo(locations
[LocNo
]))
348 if (KeepLoc
== locations
.size())
351 // Keep the smaller location, erase the larger one.
352 unsigned EraseLoc
= LocNo
;
353 if (KeepLoc
> EraseLoc
)
354 std::swap(KeepLoc
, EraseLoc
);
355 locations
.erase(locations
.begin() + EraseLoc
);
358 for (LocMap::iterator I
= locInts
.begin(); I
.valid(); ++I
) {
359 unsigned v
= I
.value();
361 I
.setValue(KeepLoc
); // Coalesce when possible.
362 else if (v
> EraseLoc
)
363 I
.setValueUnchecked(v
-1); // Avoid coalescing with untransformed values.
367 void UserValue::mapVirtRegs(LDVImpl
*LDV
) {
368 for (unsigned i
= 0, e
= locations
.size(); i
!= e
; ++i
)
369 if (locations
[i
].isReg() &&
370 TargetRegisterInfo::isVirtualRegister(locations
[i
].getReg()))
371 LDV
->mapVirtReg(locations
[i
].getReg(), this);
374 UserValue
*LDVImpl::getUserValue(const MDNode
*Var
, unsigned Offset
,
376 UserValue
*&Leader
= userVarMap
[Var
];
378 UserValue
*UV
= Leader
->getLeader();
380 for (; UV
; UV
= UV
->getNext())
381 if (UV
->match(Var
, Offset
))
385 UserValue
*UV
= new UserValue(Var
, Offset
, DL
, allocator
);
386 userValues
.push_back(UV
);
387 Leader
= UserValue::merge(Leader
, UV
);
391 void LDVImpl::mapVirtReg(unsigned VirtReg
, UserValue
*EC
) {
392 assert(TargetRegisterInfo::isVirtualRegister(VirtReg
) && "Only map VirtRegs");
393 UserValue
*&Leader
= virtRegToEqClass
[VirtReg
];
394 Leader
= UserValue::merge(Leader
, EC
);
397 UserValue
*LDVImpl::lookupVirtReg(unsigned VirtReg
) {
398 if (UserValue
*UV
= virtRegToEqClass
.lookup(VirtReg
))
399 return UV
->getLeader();
403 bool LDVImpl::handleDebugValue(MachineInstr
*MI
, SlotIndex Idx
) {
404 // DBG_VALUE loc, offset, variable
405 if (MI
->getNumOperands() != 3 ||
406 !MI
->getOperand(1).isImm() || !MI
->getOperand(2).isMetadata()) {
407 DEBUG(dbgs() << "Can't handle " << *MI
);
411 // Get or create the UserValue for (variable,offset).
412 unsigned Offset
= MI
->getOperand(1).getImm();
413 const MDNode
*Var
= MI
->getOperand(2).getMetadata();
414 UserValue
*UV
= getUserValue(Var
, Offset
, MI
->getDebugLoc());
415 UV
->addDef(Idx
, MI
->getOperand(0));
419 bool LDVImpl::collectDebugValues(MachineFunction
&mf
) {
420 bool Changed
= false;
421 for (MachineFunction::iterator MFI
= mf
.begin(), MFE
= mf
.end(); MFI
!= MFE
;
423 MachineBasicBlock
*MBB
= MFI
;
424 for (MachineBasicBlock::iterator MBBI
= MBB
->begin(), MBBE
= MBB
->end();
426 if (!MBBI
->isDebugValue()) {
430 // DBG_VALUE has no slot index, use the previous instruction instead.
431 SlotIndex Idx
= MBBI
== MBB
->begin() ?
432 LIS
->getMBBStartIdx(MBB
) :
433 LIS
->getInstructionIndex(llvm::prior(MBBI
)).getDefIndex();
434 // Handle consecutive DBG_VALUE instructions with the same slot index.
436 if (handleDebugValue(MBBI
, Idx
)) {
437 MBBI
= MBB
->erase(MBBI
);
441 } while (MBBI
!= MBBE
&& MBBI
->isDebugValue());
447 void UserValue::extendDef(SlotIndex Idx
, unsigned LocNo
,
448 LiveInterval
*LI
, const VNInfo
*VNI
,
449 SmallVectorImpl
<SlotIndex
> *Kills
,
450 LiveIntervals
&LIS
, MachineDominatorTree
&MDT
) {
451 SmallVector
<SlotIndex
, 16> Todo
;
455 SlotIndex Start
= Todo
.pop_back_val();
456 MachineBasicBlock
*MBB
= LIS
.getMBBFromIndex(Start
);
457 SlotIndex Stop
= LIS
.getMBBEndIdx(MBB
);
458 LocMap::iterator I
= locInts
.find(Start
);
460 // Limit to VNI's live range.
463 LiveRange
*Range
= LI
->getLiveRangeContaining(Start
);
464 if (!Range
|| Range
->valno
!= VNI
) {
466 Kills
->push_back(Start
);
469 if (Range
->end
< Stop
)
470 Stop
= Range
->end
, ToEnd
= false;
473 // There could already be a short def at Start.
474 if (I
.valid() && I
.start() <= Start
) {
475 // Stop when meeting a different location or an already extended interval.
476 Start
= Start
.getNextSlot();
477 if (I
.value() != LocNo
|| I
.stop() != Start
)
479 // This is a one-slot placeholder. Just skip it.
483 // Limited by the next def.
484 if (I
.valid() && I
.start() < Stop
)
485 Stop
= I
.start(), ToEnd
= false;
486 // Limited by VNI's live range.
487 else if (!ToEnd
&& Kills
)
488 Kills
->push_back(Stop
);
493 I
.insert(Start
, Stop
, LocNo
);
495 // If we extended to the MBB end, propagate down the dominator tree.
498 const std::vector
<MachineDomTreeNode
*> &Children
=
499 MDT
.getNode(MBB
)->getChildren();
500 for (unsigned i
= 0, e
= Children
.size(); i
!= e
; ++i
)
501 Todo
.push_back(LIS
.getMBBStartIdx(Children
[i
]->getBlock()));
502 } while (!Todo
.empty());
506 UserValue::addDefsFromCopies(LiveInterval
*LI
, unsigned LocNo
,
507 const SmallVectorImpl
<SlotIndex
> &Kills
,
508 SmallVectorImpl
<std::pair
<SlotIndex
, unsigned> > &NewDefs
,
509 MachineRegisterInfo
&MRI
, LiveIntervals
&LIS
) {
512 // Don't track copies from physregs, there are too many uses.
513 if (!TargetRegisterInfo::isVirtualRegister(LI
->reg
))
516 // Collect all the (vreg, valno) pairs that are copies of LI.
517 SmallVector
<std::pair
<LiveInterval
*, const VNInfo
*>, 8> CopyValues
;
518 for (MachineRegisterInfo::use_nodbg_iterator
519 UI
= MRI
.use_nodbg_begin(LI
->reg
),
520 UE
= MRI
.use_nodbg_end(); UI
!= UE
; ++UI
) {
521 // Copies of the full value.
522 if (UI
.getOperand().getSubReg() || !UI
->isCopy())
524 MachineInstr
*MI
= &*UI
;
525 unsigned DstReg
= MI
->getOperand(0).getReg();
527 // Don't follow copies to physregs. These are usually setting up call
528 // arguments, and the argument registers are always call clobbered. We are
529 // better off in the source register which could be a callee-saved register,
530 // or it could be spilled.
531 if (!TargetRegisterInfo::isVirtualRegister(DstReg
))
534 // Is LocNo extended to reach this copy? If not, another def may be blocking
535 // it, or we are looking at a wrong value of LI.
536 SlotIndex Idx
= LIS
.getInstructionIndex(MI
);
537 LocMap::iterator I
= locInts
.find(Idx
.getUseIndex());
538 if (!I
.valid() || I
.value() != LocNo
)
541 if (!LIS
.hasInterval(DstReg
))
543 LiveInterval
*DstLI
= &LIS
.getInterval(DstReg
);
544 const VNInfo
*DstVNI
= DstLI
->getVNInfoAt(Idx
.getDefIndex());
545 assert(DstVNI
&& DstVNI
->def
== Idx
.getDefIndex() && "Bad copy value");
546 CopyValues
.push_back(std::make_pair(DstLI
, DstVNI
));
549 if (CopyValues
.empty())
552 DEBUG(dbgs() << "Got " << CopyValues
.size() << " copies of " << *LI
<< '\n');
554 // Try to add defs of the copied values for each kill point.
555 for (unsigned i
= 0, e
= Kills
.size(); i
!= e
; ++i
) {
556 SlotIndex Idx
= Kills
[i
];
557 for (unsigned j
= 0, e
= CopyValues
.size(); j
!= e
; ++j
) {
558 LiveInterval
*DstLI
= CopyValues
[j
].first
;
559 const VNInfo
*DstVNI
= CopyValues
[j
].second
;
560 if (DstLI
->getVNInfoAt(Idx
) != DstVNI
)
562 // Check that there isn't already a def at Idx
563 LocMap::iterator I
= locInts
.find(Idx
);
564 if (I
.valid() && I
.start() <= Idx
)
566 DEBUG(dbgs() << "Kill at " << Idx
<< " covered by valno #"
567 << DstVNI
->id
<< " in " << *DstLI
<< '\n');
568 MachineInstr
*CopyMI
= LIS
.getInstructionFromIndex(DstVNI
->def
);
569 assert(CopyMI
&& CopyMI
->isCopy() && "Bad copy value");
570 unsigned LocNo
= getLocationNo(CopyMI
->getOperand(0));
571 I
.insert(Idx
, Idx
.getNextSlot(), LocNo
);
572 NewDefs
.push_back(std::make_pair(Idx
, LocNo
));
579 UserValue::computeIntervals(MachineRegisterInfo
&MRI
,
581 MachineDominatorTree
&MDT
) {
582 SmallVector
<std::pair
<SlotIndex
, unsigned>, 16> Defs
;
584 // Collect all defs to be extended (Skipping undefs).
585 for (LocMap::const_iterator I
= locInts
.begin(); I
.valid(); ++I
)
586 if (I
.value() != ~0u)
587 Defs
.push_back(std::make_pair(I
.start(), I
.value()));
589 // Extend all defs, and possibly add new ones along the way.
590 for (unsigned i
= 0; i
!= Defs
.size(); ++i
) {
591 SlotIndex Idx
= Defs
[i
].first
;
592 unsigned LocNo
= Defs
[i
].second
;
593 const MachineOperand
&Loc
= locations
[LocNo
];
595 // Register locations are constrained to where the register value is live.
596 if (Loc
.isReg() && LIS
.hasInterval(Loc
.getReg())) {
597 LiveInterval
*LI
= &LIS
.getInterval(Loc
.getReg());
598 const VNInfo
*VNI
= LI
->getVNInfoAt(Idx
);
599 SmallVector
<SlotIndex
, 16> Kills
;
600 extendDef(Idx
, LocNo
, LI
, VNI
, &Kills
, LIS
, MDT
);
601 addDefsFromCopies(LI
, LocNo
, Kills
, Defs
, MRI
, LIS
);
603 extendDef(Idx
, LocNo
, 0, 0, 0, LIS
, MDT
);
606 // Finally, erase all the undefs.
607 for (LocMap::iterator I
= locInts
.begin(); I
.valid();)
608 if (I
.value() == ~0u)
614 void LDVImpl::computeIntervals() {
615 for (unsigned i
= 0, e
= userValues
.size(); i
!= e
; ++i
) {
616 userValues
[i
]->computeIntervals(MF
->getRegInfo(), *LIS
, *MDT
);
617 userValues
[i
]->mapVirtRegs(this);
621 bool LDVImpl::runOnMachineFunction(MachineFunction
&mf
) {
623 LIS
= &pass
.getAnalysis
<LiveIntervals
>();
624 MDT
= &pass
.getAnalysis
<MachineDominatorTree
>();
625 TRI
= mf
.getTarget().getRegisterInfo();
627 DEBUG(dbgs() << "********** COMPUTING LIVE DEBUG VARIABLES: "
628 << ((Value
*)mf
.getFunction())->getName()
631 bool Changed
= collectDebugValues(mf
);
633 DEBUG(print(dbgs()));
637 bool LiveDebugVariables::runOnMachineFunction(MachineFunction
&mf
) {
641 pImpl
= new LDVImpl(this);
642 return static_cast<LDVImpl
*>(pImpl
)->runOnMachineFunction(mf
);
645 void LiveDebugVariables::releaseMemory() {
647 static_cast<LDVImpl
*>(pImpl
)->clear();
650 LiveDebugVariables::~LiveDebugVariables() {
652 delete static_cast<LDVImpl
*>(pImpl
);
656 renameRegister(unsigned OldReg
, unsigned NewReg
, unsigned SubIdx
,
657 const TargetRegisterInfo
*TRI
) {
658 for (unsigned i
= locations
.size(); i
; --i
) {
659 unsigned LocNo
= i
- 1;
660 MachineOperand
&Loc
= locations
[LocNo
];
661 if (!Loc
.isReg() || Loc
.getReg() != OldReg
)
663 if (TargetRegisterInfo::isPhysicalRegister(NewReg
))
664 Loc
.substPhysReg(NewReg
, *TRI
);
666 Loc
.substVirtReg(NewReg
, SubIdx
, *TRI
);
667 coalesceLocation(LocNo
);
672 renameRegister(unsigned OldReg
, unsigned NewReg
, unsigned SubIdx
) {
673 UserValue
*UV
= lookupVirtReg(OldReg
);
677 if (TargetRegisterInfo::isVirtualRegister(NewReg
))
678 mapVirtReg(NewReg
, UV
);
679 virtRegToEqClass
.erase(OldReg
);
682 UV
->renameRegister(OldReg
, NewReg
, SubIdx
, TRI
);
687 void LiveDebugVariables::
688 renameRegister(unsigned OldReg
, unsigned NewReg
, unsigned SubIdx
) {
690 static_cast<LDVImpl
*>(pImpl
)->renameRegister(OldReg
, NewReg
, SubIdx
);
693 //===----------------------------------------------------------------------===//
694 // Live Range Splitting
695 //===----------------------------------------------------------------------===//
698 UserValue::splitLocation(unsigned OldLocNo
, ArrayRef
<LiveInterval
*> NewRegs
) {
700 dbgs() << "Splitting Loc" << OldLocNo
<< '\t';
703 bool DidChange
= false;
704 LocMap::iterator LocMapI
;
705 LocMapI
.setMap(locInts
);
706 for (unsigned i
= 0; i
!= NewRegs
.size(); ++i
) {
707 LiveInterval
*LI
= NewRegs
[i
];
711 // Don't allocate the new LocNo until it is needed.
712 unsigned NewLocNo
= ~0u;
714 // Iterate over the overlaps between locInts and LI.
715 LocMapI
.find(LI
->beginIndex());
716 if (!LocMapI
.valid())
718 LiveInterval::iterator LII
= LI
->advanceTo(LI
->begin(), LocMapI
.start());
719 LiveInterval::iterator LIE
= LI
->end();
720 while (LocMapI
.valid() && LII
!= LIE
) {
721 // At this point, we know that LocMapI.stop() > LII->start.
722 LII
= LI
->advanceTo(LII
, LocMapI
.start());
726 // Now LII->end > LocMapI.start(). Do we have an overlap?
727 if (LocMapI
.value() == OldLocNo
&& LII
->start
< LocMapI
.stop()) {
728 // Overlapping correct location. Allocate NewLocNo now.
729 if (NewLocNo
== ~0u) {
730 MachineOperand MO
= MachineOperand::CreateReg(LI
->reg
, false);
731 MO
.setSubReg(locations
[OldLocNo
].getSubReg());
732 NewLocNo
= getLocationNo(MO
);
736 SlotIndex LStart
= LocMapI
.start();
737 SlotIndex LStop
= LocMapI
.stop();
739 // Trim LocMapI down to the LII overlap.
740 if (LStart
< LII
->start
)
741 LocMapI
.setStartUnchecked(LII
->start
);
742 if (LStop
> LII
->end
)
743 LocMapI
.setStopUnchecked(LII
->end
);
745 // Change the value in the overlap. This may trigger coalescing.
746 LocMapI
.setValue(NewLocNo
);
748 // Re-insert any removed OldLocNo ranges.
749 if (LStart
< LocMapI
.start()) {
750 LocMapI
.insert(LStart
, LocMapI
.start(), OldLocNo
);
752 assert(LocMapI
.valid() && "Unexpected coalescing");
754 if (LStop
> LocMapI
.stop()) {
756 LocMapI
.insert(LII
->end
, LStop
, OldLocNo
);
761 // Advance to the next overlap.
762 if (LII
->end
< LocMapI
.stop()) {
765 LocMapI
.advanceTo(LII
->start
);
768 if (!LocMapI
.valid())
770 LII
= LI
->advanceTo(LII
, LocMapI
.start());
775 // Finally, remove any remaining OldLocNo intervals and OldLocNo itself.
776 locations
.erase(locations
.begin() + OldLocNo
);
778 while (LocMapI
.valid()) {
779 unsigned v
= LocMapI
.value();
781 DEBUG(dbgs() << "Erasing [" << LocMapI
.start() << ';'
782 << LocMapI
.stop() << ")\n");
786 LocMapI
.setValueUnchecked(v
-1);
791 DEBUG({dbgs() << "Split result: \t"; print(dbgs(), 0);});
796 UserValue::splitRegister(unsigned OldReg
, ArrayRef
<LiveInterval
*> NewRegs
) {
797 bool DidChange
= false;
798 // Split locations referring to OldReg. Iterate backwards so splitLocation can
799 // safely erase unuused locations.
800 for (unsigned i
= locations
.size(); i
; --i
) {
801 unsigned LocNo
= i
-1;
802 const MachineOperand
*Loc
= &locations
[LocNo
];
803 if (!Loc
->isReg() || Loc
->getReg() != OldReg
)
805 DidChange
|= splitLocation(LocNo
, NewRegs
);
810 void LDVImpl::splitRegister(unsigned OldReg
, ArrayRef
<LiveInterval
*> NewRegs
) {
811 bool DidChange
= false;
812 for (UserValue
*UV
= lookupVirtReg(OldReg
); UV
; UV
= UV
->getNext())
813 DidChange
|= UV
->splitRegister(OldReg
, NewRegs
);
818 // Map all of the new virtual registers.
819 UserValue
*UV
= lookupVirtReg(OldReg
);
820 for (unsigned i
= 0; i
!= NewRegs
.size(); ++i
)
821 mapVirtReg(NewRegs
[i
]->reg
, UV
);
824 void LiveDebugVariables::
825 splitRegister(unsigned OldReg
, ArrayRef
<LiveInterval
*> NewRegs
) {
827 static_cast<LDVImpl
*>(pImpl
)->splitRegister(OldReg
, NewRegs
);
831 UserValue::rewriteLocations(VirtRegMap
&VRM
, const TargetRegisterInfo
&TRI
) {
832 // Iterate over locations in reverse makes it easier to handle coalescing.
833 for (unsigned i
= locations
.size(); i
; --i
) {
834 unsigned LocNo
= i
-1;
835 MachineOperand
&Loc
= locations
[LocNo
];
836 // Only virtual registers are rewritten.
837 if (!Loc
.isReg() || !Loc
.getReg() ||
838 !TargetRegisterInfo::isVirtualRegister(Loc
.getReg()))
840 unsigned VirtReg
= Loc
.getReg();
841 if (VRM
.isAssignedReg(VirtReg
) &&
842 TargetRegisterInfo::isPhysicalRegister(VRM
.getPhys(VirtReg
))) {
843 // This can create a %noreg operand in rare cases when the sub-register
844 // index is no longer available. That means the user value is in a
845 // non-existent sub-register, and %noreg is exactly what we want.
846 Loc
.substPhysReg(VRM
.getPhys(VirtReg
), TRI
);
847 } else if (VRM
.getStackSlot(VirtReg
) != VirtRegMap::NO_STACK_SLOT
&&
848 VRM
.isSpillSlotUsed(VRM
.getStackSlot(VirtReg
))) {
849 // FIXME: Translate SubIdx to a stackslot offset.
850 Loc
= MachineOperand::CreateFI(VRM
.getStackSlot(VirtReg
));
855 coalesceLocation(LocNo
);
859 /// findInsertLocation - Find an iterator for inserting a DBG_VALUE
861 static MachineBasicBlock::iterator
862 findInsertLocation(MachineBasicBlock
*MBB
, SlotIndex Idx
,
863 LiveIntervals
&LIS
) {
864 SlotIndex Start
= LIS
.getMBBStartIdx(MBB
);
865 Idx
= Idx
.getBaseIndex();
867 // Try to find an insert location by going backwards from Idx.
869 while (!(MI
= LIS
.getInstructionFromIndex(Idx
))) {
870 // We've reached the beginning of MBB.
872 MachineBasicBlock::iterator I
= MBB
->SkipPHIsAndLabels(MBB
->begin());
875 Idx
= Idx
.getPrevIndex();
878 // Don't insert anything after the first terminator, though.
879 return MI
->getDesc().isTerminator() ? MBB
->getFirstTerminator() :
880 llvm::next(MachineBasicBlock::iterator(MI
));
883 DebugLoc
UserValue::findDebugLoc() {
888 void UserValue::insertDebugValue(MachineBasicBlock
*MBB
, SlotIndex Idx
,
891 const TargetInstrInfo
&TII
) {
892 MachineBasicBlock::iterator I
= findInsertLocation(MBB
, Idx
, LIS
);
893 MachineOperand
&Loc
= locations
[LocNo
];
895 // Frame index locations may require a target callback.
897 MachineInstr
*MI
= TII
.emitFrameIndexDebugValue(*MBB
->getParent(),
898 Loc
.getIndex(), offset
, variable
,
905 // This is not a frame index, or the target is happy with a standard FI.
906 BuildMI(*MBB
, I
, findDebugLoc(), TII
.get(TargetOpcode::DBG_VALUE
))
907 .addOperand(Loc
).addImm(offset
).addMetadata(variable
);
910 void UserValue::emitDebugValues(VirtRegMap
*VRM
, LiveIntervals
&LIS
,
911 const TargetInstrInfo
&TII
) {
912 MachineFunction::iterator MFEnd
= VRM
->getMachineFunction().end();
914 for (LocMap::const_iterator I
= locInts
.begin(); I
.valid();) {
915 SlotIndex Start
= I
.start();
916 SlotIndex Stop
= I
.stop();
917 unsigned LocNo
= I
.value();
918 DEBUG(dbgs() << "\t[" << Start
<< ';' << Stop
<< "):" << LocNo
);
919 MachineFunction::iterator MBB
= LIS
.getMBBFromIndex(Start
);
920 SlotIndex MBBEnd
= LIS
.getMBBEndIdx(MBB
);
922 DEBUG(dbgs() << " BB#" << MBB
->getNumber() << '-' << MBBEnd
);
923 insertDebugValue(MBB
, Start
, LocNo
, LIS
, TII
);
925 // This interval may span multiple basic blocks.
926 // Insert a DBG_VALUE into each one.
927 while(Stop
> MBBEnd
) {
928 // Move to the next block.
932 MBBEnd
= LIS
.getMBBEndIdx(MBB
);
933 DEBUG(dbgs() << " BB#" << MBB
->getNumber() << '-' << MBBEnd
);
934 insertDebugValue(MBB
, Start
, LocNo
, LIS
, TII
);
936 DEBUG(dbgs() << '\n');
944 void LDVImpl::emitDebugValues(VirtRegMap
*VRM
) {
945 DEBUG(dbgs() << "********** EMITTING LIVE DEBUG VARIABLES **********\n");
946 const TargetInstrInfo
*TII
= MF
->getTarget().getInstrInfo();
947 for (unsigned i
= 0, e
= userValues
.size(); i
!= e
; ++i
) {
948 DEBUG(userValues
[i
]->print(dbgs(), &MF
->getTarget()));
949 userValues
[i
]->rewriteLocations(*VRM
, *TRI
);
950 userValues
[i
]->emitDebugValues(VRM
, *LIS
, *TII
);
954 void LiveDebugVariables::emitDebugValues(VirtRegMap
*VRM
) {
956 static_cast<LDVImpl
*>(pImpl
)->emitDebugValues(VRM
);
961 void LiveDebugVariables::dump() {
963 static_cast<LDVImpl
*>(pImpl
)->print(dbgs());