llvm-6502/lib/CodeGen/LiveDebugVariables.cpp
2010-12-03 22:25:09 +00:00

825 lines
26 KiB
C++

//===- LiveDebugVariables.cpp - Tracking debug info variables -------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements the LiveDebugVariables analysis.
//
// Remove all DBG_VALUE instructions referencing virtual registers and replace
// them with a data structure tracking where live user variables are kept - in a
// virtual register or in a stack slot.
//
// Allow the data structure to be updated during register allocation when values
// are moved between registers and stack slots. Finally emit new DBG_VALUE
// instructions after register allocation is complete.
//
//===----------------------------------------------------------------------===//
#define DEBUG_TYPE "livedebug"
#include "LiveDebugVariables.h"
#include "VirtRegMap.h"
#include "llvm/Constants.h"
#include "llvm/Metadata.h"
#include "llvm/Value.h"
#include "llvm/ADT/IntervalMap.h"
#include "llvm/CodeGen/LiveIntervalAnalysis.h"
#include "llvm/CodeGen/MachineDominators.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/Passes.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/Debug.h"
#include "llvm/Target/TargetInstrInfo.h"
#include "llvm/Target/TargetMachine.h"
#include "llvm/Target/TargetRegisterInfo.h"
using namespace llvm;
static cl::opt<bool>
EnableLDV("live-debug-variables",
cl::desc("Enable the live debug variables pass"), cl::Hidden);
char LiveDebugVariables::ID = 0;
INITIALIZE_PASS_BEGIN(LiveDebugVariables, "livedebugvars",
"Debug Variable Analysis", false, false)
INITIALIZE_PASS_DEPENDENCY(MachineDominatorTree)
INITIALIZE_PASS_DEPENDENCY(LiveIntervals)
INITIALIZE_PASS_END(LiveDebugVariables, "livedebugvars",
"Debug Variable Analysis", false, false)
void LiveDebugVariables::getAnalysisUsage(AnalysisUsage &AU) const {
AU.addRequired<MachineDominatorTree>();
AU.addRequiredTransitive<LiveIntervals>();
AU.setPreservesAll();
MachineFunctionPass::getAnalysisUsage(AU);
}
LiveDebugVariables::LiveDebugVariables() : MachineFunctionPass(ID), pImpl(0) {
initializeLiveDebugVariablesPass(*PassRegistry::getPassRegistry());
}
/// Location - All the different places a user value can reside.
/// Note that this includes immediate values that technically aren't locations.
namespace {
struct Location {
/// kind - What kind of location is this?
enum Kind {
locUndef = 0,
locImm = 0x80000000,
locFPImm
};
/// Kind - One of the following:
/// 1. locUndef
/// 2. Register number (physical or virtual), data.SubIdx is the subreg index.
/// 3. ~Frame index, data.Offset is the offset.
/// 4. locImm, data.ImmVal is the constant integer value.
/// 5. locFPImm, data.CFP points to the floating point constant.
unsigned Kind;
/// Data - Extra data about location.
union {
unsigned SubIdx; ///< For virtual registers.
int64_t Offset; ///< For frame indices.
int64_t ImmVal; ///< For locImm.
const ConstantFP *CFP; ///< For locFPImm.
} Data;
Location(const MachineOperand &MO) {
switch(MO.getType()) {
case MachineOperand::MO_Register:
Kind = MO.getReg();
Data.SubIdx = MO.getSubReg();
return;
case MachineOperand::MO_Immediate:
Kind = locImm;
Data.ImmVal = MO.getImm();
return;
case MachineOperand::MO_FPImmediate:
Kind = locFPImm;
Data.CFP = MO.getFPImm();
return;
case MachineOperand::MO_FrameIndex:
Kind = ~MO.getIndex();
// FIXME: MO_FrameIndex should support an offset.
Data.Offset = 0;
return;
default:
Kind = locUndef;
return;
}
}
/// addOperand - Add this location as a machine operand to MI.
MachineInstrBuilder addOperand(MachineInstrBuilder MI) const {
switch (Kind) {
case locImm:
return MI.addImm(Data.ImmVal);
case locFPImm:
return MI.addFPImm(Data.CFP);
default:
if (isFrameIndex())
return MI.addFrameIndex(getFrameIndex());
else
return MI.addReg(Kind); // reg and undef.
}
}
bool operator==(const Location &RHS) const {
if (Kind != RHS.Kind)
return false;
switch (Kind) {
case locUndef:
return true;
case locImm:
return Data.ImmVal == RHS.Data.ImmVal;
case locFPImm:
return Data.CFP == RHS.Data.CFP;
default:
if (isReg())
return Data.SubIdx == RHS.Data.SubIdx;
else
return Data.Offset == RHS.Data.Offset;
}
}
/// isUndef - is this the singleton undef?
bool isUndef() const { return Kind == locUndef; }
/// isReg - is this a register location?
bool isReg() const { return Kind && Kind < locImm; }
/// isFrameIndex - is this a frame index location?
bool isFrameIndex() const { return Kind > locFPImm; }
int getFrameIndex() const { return ~Kind; }
void print(raw_ostream&, const TargetRegisterInfo*);
};
}
/// LocMap - Map of where a user value is live, and its location.
typedef IntervalMap<SlotIndex, unsigned, 4> LocMap;
/// UserValue - A user value is a part of a debug info user variable.
///
/// A DBG_VALUE instruction notes that (a sub-register of) a virtual register
/// holds part of a user variable. The part is identified by a byte offset.
///
/// UserValues are grouped into equivalence classes for easier searching. Two
/// user values are related if they refer to the same variable, or if they are
/// held by the same virtual register. The equivalence class is the transitive
/// closure of that relation.
namespace {
class UserValue {
const MDNode *variable; ///< The debug info variable we are part of.
unsigned offset; ///< Byte offset into variable.
UserValue *leader; ///< Equivalence class leader.
UserValue *next; ///< Next value in equivalence class, or null.
/// Numbered locations referenced by locmap.
SmallVector<Location, 4> locations;
/// Map of slot indices where this value is live.
LocMap locInts;
/// coalesceLocation - After LocNo was changed, check if it has become
/// identical to another location, and coalesce them. This may cause LocNo or
/// a later location to be erased, but no earlier location will be erased.
void coalesceLocation(unsigned LocNo);
/// insertDebugValue - Insert a DBG_VALUE into MBB at Idx for LocNo.
void insertDebugValue(MachineBasicBlock *MBB, SlotIndex Idx, unsigned LocNo,
LiveIntervals &LIS, const TargetInstrInfo &TII);
/// insertDebugKill - Insert an undef DBG_VALUE into MBB at Idx.
void insertDebugKill(MachineBasicBlock *MBB, SlotIndex Idx,
LiveIntervals &LIS, const TargetInstrInfo &TII);
public:
/// UserValue - Create a new UserValue.
UserValue(const MDNode *var, unsigned o, LocMap::Allocator &alloc)
: variable(var), offset(o), leader(this), next(0), locInts(alloc)
{}
/// getLeader - Get the leader of this value's equivalence class.
UserValue *getLeader() {
UserValue *l = leader;
while (l != l->leader)
l = l->leader;
return leader = l;
}
/// getNext - Return the next UserValue in the equivalence class.
UserValue *getNext() const { return next; }
/// match - Does this UserValue match the aprameters?
bool match(const MDNode *Var, unsigned Offset) const {
return Var == variable && Offset == offset;
}
/// merge - Merge equivalence classes.
static UserValue *merge(UserValue *L1, UserValue *L2) {
L2 = L2->getLeader();
if (!L1)
return L2;
L1 = L1->getLeader();
if (L1 == L2)
return L1;
// Splice L2 before L1's members.
UserValue *End = L2;
while (End->next)
End->leader = L1, End = End->next;
End->leader = L1;
End->next = L1->next;
L1->next = L2;
return L1;
}
/// getLocationNo - Return the location number that matches Loc.
unsigned getLocationNo(Location Loc) {
if (Loc.isUndef())
return ~0u;
unsigned n = std::find(locations.begin(), locations.end(), Loc) -
locations.begin();
if (n == locations.size())
locations.push_back(Loc);
return n;
}
/// addDef - Add a definition point to this value.
void addDef(SlotIndex Idx, const MachineOperand &LocMO) {
// Add a singular (Idx,Idx) -> Loc mapping.
LocMap::iterator I = locInts.find(Idx);
if (!I.valid() || I.start() != Idx)
I.insert(Idx, Idx.getNextSlot(), getLocationNo(LocMO));
}
/// extendDef - Extend the current definition as far as possible down the
/// dominator tree. Stop when meeting an existing def or when leaving the live
/// range of VNI.
/// @param Idx Starting point for the definition.
/// @param LocNo Location number to propagate.
/// @param LI Restrict liveness to where LI has the value VNI. May be null.
/// @param VNI When LI is not null, this is the value to restrict to.
/// @param LIS Live intervals analysis.
/// @param MDT Dominator tree.
void extendDef(SlotIndex Idx, unsigned LocNo,
LiveInterval *LI, const VNInfo *VNI,
LiveIntervals &LIS, MachineDominatorTree &MDT);
/// computeIntervals - Compute the live intervals of all locations after
/// collecting all their def points.
void computeIntervals(LiveIntervals &LIS, MachineDominatorTree &MDT);
/// renameRegister - Update locations to rewrite OldReg as NewReg:SubIdx.
void renameRegister(unsigned OldReg, unsigned NewReg, unsigned SubIdx,
const TargetRegisterInfo *TRI);
/// rewriteLocations - Rewrite virtual register locations according to the
/// provided virtual register map.
void rewriteLocations(VirtRegMap &VRM, const TargetRegisterInfo &TRI);
/// emitDebugVariables - Recreate DBG_VALUE instruction from data structures.
void emitDebugValues(VirtRegMap *VRM,
LiveIntervals &LIS, const TargetInstrInfo &TRI);
void print(raw_ostream&, const TargetRegisterInfo*);
};
} // namespace
/// LDVImpl - Implementation of the LiveDebugVariables pass.
namespace {
class LDVImpl {
LiveDebugVariables &pass;
LocMap::Allocator allocator;
MachineFunction *MF;
LiveIntervals *LIS;
MachineDominatorTree *MDT;
const TargetRegisterInfo *TRI;
/// userValues - All allocated UserValue instances.
SmallVector<UserValue*, 8> userValues;
/// Map virtual register to eq class leader.
typedef DenseMap<unsigned, UserValue*> VRMap;
VRMap virtRegToEqClass;
/// Map user variable to eq class leader.
typedef DenseMap<const MDNode *, UserValue*> UVMap;
UVMap userVarMap;
/// getUserValue - Find or create a UserValue.
UserValue *getUserValue(const MDNode *Var, unsigned Offset);
/// lookupVirtReg - Find the EC leader for VirtReg or null.
UserValue *lookupVirtReg(unsigned VirtReg);
/// mapVirtReg - Map virtual register to an equivalence class.
void mapVirtReg(unsigned VirtReg, UserValue *EC);
/// handleDebugValue - Add DBG_VALUE instruction to our maps.
/// @param MI DBG_VALUE instruction
/// @param Idx Last valid SLotIndex before instruction.
/// @return True if the DBG_VALUE instruction should be deleted.
bool handleDebugValue(MachineInstr *MI, SlotIndex Idx);
/// collectDebugValues - Collect and erase all DBG_VALUE instructions, adding
/// a UserValue def for each instruction.
/// @param mf MachineFunction to be scanned.
/// @return True if any debug values were found.
bool collectDebugValues(MachineFunction &mf);
/// computeIntervals - Compute the live intervals of all user values after
/// collecting all their def points.
void computeIntervals();
public:
LDVImpl(LiveDebugVariables *ps) : pass(*ps) {}
bool runOnMachineFunction(MachineFunction &mf);
/// clear - Relase all memory.
void clear() {
DeleteContainerPointers(userValues);
userValues.clear();
virtRegToEqClass.clear();
userVarMap.clear();
}
/// renameRegister - Replace all references to OldReg wiht NewReg:SubIdx.
void renameRegister(unsigned OldReg, unsigned NewReg, unsigned SubIdx);
/// emitDebugVariables - Recreate DBG_VALUE instruction from data structures.
void emitDebugValues(VirtRegMap *VRM);
void print(raw_ostream&);
};
} // namespace
void Location::print(raw_ostream &OS, const TargetRegisterInfo *TRI) {
switch (Kind) {
case locUndef:
OS << "undef";
return;
case locImm:
OS << "int:" << Data.ImmVal;
return;
case locFPImm:
OS << "fp:" << Data.CFP->getValueAPF().convertToDouble();
return;
default:
if (isReg()) {
if (TargetRegisterInfo::isVirtualRegister(Kind)) {
OS << "%reg" << Kind;
if (Data.SubIdx)
OS << ':' << TRI->getSubRegIndexName(Data.SubIdx);
} else
OS << '%' << TRI->getName(Kind);
} else {
OS << "fi#" << ~Kind;
if (Data.Offset)
OS << '+' << Data.Offset;
}
return;
}
}
void UserValue::print(raw_ostream &OS, const TargetRegisterInfo *TRI) {
if (const MDString *MDS = dyn_cast<MDString>(variable->getOperand(2)))
OS << "!\"" << MDS->getString() << "\"\t";
if (offset)
OS << '+' << offset;
for (LocMap::const_iterator I = locInts.begin(); I.valid(); ++I) {
OS << " [" << I.start() << ';' << I.stop() << "):";
if (I.value() == ~0u)
OS << "undef";
else
OS << I.value();
}
for (unsigned i = 0, e = locations.size(); i != e; ++i) {
OS << " Loc" << i << '=';
locations[i].print(OS, TRI);
}
OS << '\n';
}
void LDVImpl::print(raw_ostream &OS) {
OS << "********** DEBUG VARIABLES **********\n";
for (unsigned i = 0, e = userValues.size(); i != e; ++i)
userValues[i]->print(OS, TRI);
}
void UserValue::coalesceLocation(unsigned LocNo) {
unsigned KeepLoc = std::find(locations.begin(), locations.begin() + LocNo,
locations[LocNo]) - locations.begin();
unsigned EraseLoc = LocNo;
if (KeepLoc == LocNo) {
EraseLoc = std::find(locations.begin() + LocNo + 1, locations.end(),
locations[LocNo]) - locations.begin();
// No matches.
if (EraseLoc == locations.size())
return;
}
assert(KeepLoc < EraseLoc);
locations.erase(locations.begin() + EraseLoc);
// Rewrite values.
for (LocMap::iterator I = locInts.begin(); I.valid(); ++I) {
unsigned v = I.value();
if (v == EraseLoc)
I.setValue(KeepLoc); // Coalesce when possible.
else if (v > EraseLoc)
I.setValueUnchecked(v-1); // Avoid coalescing with untransformed values.
}
}
UserValue *LDVImpl::getUserValue(const MDNode *Var, unsigned Offset) {
UserValue *&Leader = userVarMap[Var];
if (Leader) {
UserValue *UV = Leader->getLeader();
Leader = UV;
for (; UV; UV = UV->getNext())
if (UV->match(Var, Offset))
return UV;
}
UserValue *UV = new UserValue(Var, Offset, allocator);
userValues.push_back(UV);
Leader = UserValue::merge(Leader, UV);
return UV;
}
void LDVImpl::mapVirtReg(unsigned VirtReg, UserValue *EC) {
assert(TargetRegisterInfo::isVirtualRegister(VirtReg) && "Only map VirtRegs");
UserValue *&Leader = virtRegToEqClass[VirtReg];
Leader = UserValue::merge(Leader, EC);
}
UserValue *LDVImpl::lookupVirtReg(unsigned VirtReg) {
if (UserValue *UV = virtRegToEqClass.lookup(VirtReg))
return UV->getLeader();
return 0;
}
bool LDVImpl::handleDebugValue(MachineInstr *MI, SlotIndex Idx) {
// DBG_VALUE loc, offset, variable
if (MI->getNumOperands() != 3 ||
!MI->getOperand(1).isImm() || !MI->getOperand(2).isMetadata()) {
DEBUG(dbgs() << "Can't handle " << *MI);
return false;
}
// Get or create the UserValue for (variable,offset).
unsigned Offset = MI->getOperand(1).getImm();
const MDNode *Var = MI->getOperand(2).getMetadata();
UserValue *UV = getUserValue(Var, Offset);
// If the location is a virtual register, make sure it is mapped.
if (MI->getOperand(0).isReg()) {
unsigned Reg = MI->getOperand(0).getReg();
if (Reg && TargetRegisterInfo::isVirtualRegister(Reg))
mapVirtReg(Reg, UV);
}
UV->addDef(Idx, MI->getOperand(0));
return true;
}
bool LDVImpl::collectDebugValues(MachineFunction &mf) {
bool Changed = false;
for (MachineFunction::iterator MFI = mf.begin(), MFE = mf.end(); MFI != MFE;
++MFI) {
MachineBasicBlock *MBB = MFI;
for (MachineBasicBlock::iterator MBBI = MBB->begin(), MBBE = MBB->end();
MBBI != MBBE;) {
if (!MBBI->isDebugValue()) {
++MBBI;
continue;
}
// DBG_VALUE has no slot index, use the previous instruction instead.
SlotIndex Idx = MBBI == MBB->begin() ?
LIS->getMBBStartIdx(MBB) :
LIS->getInstructionIndex(llvm::prior(MBBI)).getDefIndex();
// Handle consecutive DBG_VALUE instructions with the same slot index.
do {
if (handleDebugValue(MBBI, Idx)) {
MBBI = MBB->erase(MBBI);
Changed = true;
} else
++MBBI;
} while (MBBI != MBBE && MBBI->isDebugValue());
}
}
return Changed;
}
void UserValue::extendDef(SlotIndex Idx, unsigned LocNo,
LiveInterval *LI, const VNInfo *VNI,
LiveIntervals &LIS, MachineDominatorTree &MDT) {
SmallVector<SlotIndex, 16> Todo;
Todo.push_back(Idx);
do {
SlotIndex Start = Todo.pop_back_val();
MachineBasicBlock *MBB = LIS.getMBBFromIndex(Start);
SlotIndex Stop = LIS.getMBBEndIdx(MBB);
LocMap::iterator I = locInts.find(Idx);
// Limit to VNI's live range.
bool ToEnd = true;
if (LI && VNI) {
LiveRange *Range = LI->getLiveRangeContaining(Start);
if (!Range || Range->valno != VNI)
continue;
if (Range->end < Stop)
Stop = Range->end, ToEnd = false;
}
// There could already be a short def at Start.
if (I.valid() && I.start() <= Start) {
// Stop when meeting a different location or an already extended interval.
Start = Start.getNextSlot();
if (I.value() != LocNo || I.stop() != Start)
continue;
// This is a one-slot placeholder. Just skip it.
++I;
}
// Limited by the next def.
if (I.valid() && I.start() < Stop)
Stop = I.start(), ToEnd = false;
if (Start >= Stop)
continue;
I.insert(Start, Stop, LocNo);
// If we extended to the MBB end, propagate down the dominator tree.
if (!ToEnd)
continue;
const std::vector<MachineDomTreeNode*> &Children =
MDT.getNode(MBB)->getChildren();
for (unsigned i = 0, e = Children.size(); i != e; ++i)
Todo.push_back(LIS.getMBBStartIdx(Children[i]->getBlock()));
} while (!Todo.empty());
}
void
UserValue::computeIntervals(LiveIntervals &LIS, MachineDominatorTree &MDT) {
SmallVector<std::pair<SlotIndex, unsigned>, 16> Defs;
// Collect all defs to be extended (Skipping undefs).
for (LocMap::const_iterator I = locInts.begin(); I.valid(); ++I)
if (I.value() != ~0u)
Defs.push_back(std::make_pair(I.start(), I.value()));
for (unsigned i = 0, e = Defs.size(); i != e; ++i) {
SlotIndex Idx = Defs[i].first;
unsigned LocNo = Defs[i].second;
const Location &Loc = locations[LocNo];
// Register locations are constrained to where the register value is live.
if (Loc.isReg() && LIS.hasInterval(Loc.Kind)) {
LiveInterval *LI = &LIS.getInterval(Loc.Kind);
const VNInfo *VNI = LI->getVNInfoAt(Idx);
extendDef(Idx, LocNo, LI, VNI, LIS, MDT);
} else
extendDef(Idx, LocNo, 0, 0, LIS, MDT);
}
// Finally, erase all the undefs.
for (LocMap::iterator I = locInts.begin(); I.valid();)
if (I.value() == ~0u)
I.erase();
else
++I;
}
void LDVImpl::computeIntervals() {
for (unsigned i = 0, e = userValues.size(); i != e; ++i)
userValues[i]->computeIntervals(*LIS, *MDT);
}
bool LDVImpl::runOnMachineFunction(MachineFunction &mf) {
MF = &mf;
LIS = &pass.getAnalysis<LiveIntervals>();
MDT = &pass.getAnalysis<MachineDominatorTree>();
TRI = mf.getTarget().getRegisterInfo();
clear();
DEBUG(dbgs() << "********** COMPUTING LIVE DEBUG VARIABLES: "
<< ((Value*)mf.getFunction())->getName()
<< " **********\n");
bool Changed = collectDebugValues(mf);
computeIntervals();
DEBUG(print(dbgs()));
return Changed;
}
bool LiveDebugVariables::runOnMachineFunction(MachineFunction &mf) {
if (!EnableLDV)
return false;
if (!pImpl)
pImpl = new LDVImpl(this);
return static_cast<LDVImpl*>(pImpl)->runOnMachineFunction(mf);
}
void LiveDebugVariables::releaseMemory() {
if (pImpl)
static_cast<LDVImpl*>(pImpl)->clear();
}
LiveDebugVariables::~LiveDebugVariables() {
if (pImpl)
delete static_cast<LDVImpl*>(pImpl);
}
void UserValue::
renameRegister(unsigned OldReg, unsigned NewReg, unsigned SubIdx,
const TargetRegisterInfo *TRI) {
for (unsigned i = locations.size(); i; --i) {
unsigned LocNo = i - 1;
Location &Loc = locations[LocNo];
if (Loc.Kind != OldReg)
continue;
Loc.Kind = NewReg;
if (SubIdx && Loc.Data.SubIdx)
Loc.Data.SubIdx = TRI->composeSubRegIndices(SubIdx, Loc.Data.SubIdx);
coalesceLocation(LocNo);
}
}
void LDVImpl::
renameRegister(unsigned OldReg, unsigned NewReg, unsigned SubIdx) {
UserValue *UV = lookupVirtReg(OldReg);
if (!UV)
return;
if (TargetRegisterInfo::isVirtualRegister(NewReg))
mapVirtReg(NewReg, UV);
virtRegToEqClass.erase(OldReg);
do {
UV->renameRegister(OldReg, NewReg, SubIdx, TRI);
UV = UV->getNext();
} while (UV);
}
void LiveDebugVariables::
renameRegister(unsigned OldReg, unsigned NewReg, unsigned SubIdx) {
if (pImpl)
static_cast<LDVImpl*>(pImpl)->renameRegister(OldReg, NewReg, SubIdx);
}
void
UserValue::rewriteLocations(VirtRegMap &VRM, const TargetRegisterInfo &TRI) {
// Iterate over locations in reverse makes it easier to handle coalescing.
for (unsigned i = locations.size(); i ; --i) {
unsigned LocNo = i-1;
Location &Loc = locations[LocNo];
// Only virtual registers are rewritten.
if (!Loc.isReg() || !TargetRegisterInfo::isVirtualRegister(Loc.Kind))
continue;
unsigned VirtReg = Loc.Kind;
if (VRM.isAssignedReg(VirtReg)) {
unsigned PhysReg = VRM.getPhys(VirtReg);
if (Loc.Data.SubIdx)
PhysReg = TRI.getSubReg(PhysReg, Loc.Data.SubIdx);
Loc.Kind = PhysReg;
Loc.Data.SubIdx = 0;
} else if (VRM.getStackSlot(VirtReg) != VirtRegMap::NO_STACK_SLOT) {
Loc.Kind = ~VRM.getStackSlot(VirtReg);
// FIXME: Translate SubIdx to a stackslot offset.
Loc.Data.Offset = 0;
} else {
Loc.Kind = Location::locUndef;
}
coalesceLocation(LocNo);
}
DEBUG(print(dbgs(), &TRI));
}
/// findInsertLocation - Find an iterator and DebugLoc for inserting a DBG_VALUE
/// instruction.
static MachineBasicBlock::iterator
findInsertLocation(MachineBasicBlock *MBB, SlotIndex Idx, DebugLoc &DL,
LiveIntervals &LIS) {
SlotIndex Start = LIS.getMBBStartIdx(MBB);
Idx = Idx.getBaseIndex();
// Try to find an insert location by going backwards from Idx.
MachineInstr *MI;
while (!(MI = LIS.getInstructionFromIndex(Idx))) {
// We've reached the beginning of MBB.
if (Idx == Start) {
MachineBasicBlock::iterator I = MBB->SkipPHIsAndLabels(MBB->begin());
if (I != MBB->end())
DL = I->getDebugLoc();
return I;
}
Idx = Idx.getPrevIndex();
}
// We found an instruction. The insert point is after the instr.
DL = MI->getDebugLoc();
return llvm::next(MachineBasicBlock::iterator(MI));
}
void UserValue::insertDebugValue(MachineBasicBlock *MBB, SlotIndex Idx,
unsigned LocNo,
LiveIntervals &LIS,
const TargetInstrInfo &TII) {
DebugLoc DL;
MachineBasicBlock::iterator I = findInsertLocation(MBB, Idx, DL, LIS);
Location &Loc = locations[LocNo];
// Frame index locations may require a target callback.
if (Loc.isFrameIndex()) {
MachineInstr *MI = TII.emitFrameIndexDebugValue(*MBB->getParent(),
Loc.getFrameIndex(),
offset, variable, DL);
if (MI) {
MBB->insert(I, MI);
return;
}
}
// This is not a frame index, or the target is happy with a standard FI.
Loc.addOperand(BuildMI(*MBB, I, DL, TII.get(TargetOpcode::DBG_VALUE)))
.addImm(offset).addMetadata(variable);
}
void UserValue::insertDebugKill(MachineBasicBlock *MBB, SlotIndex Idx,
LiveIntervals &LIS, const TargetInstrInfo &TII) {
DebugLoc DL;
MachineBasicBlock::iterator I = findInsertLocation(MBB, Idx, DL, LIS);
BuildMI(*MBB, I, DL, TII.get(TargetOpcode::DBG_VALUE)).addReg(0)
.addImm(offset).addMetadata(variable);
}
void UserValue::emitDebugValues(VirtRegMap *VRM, LiveIntervals &LIS,
const TargetInstrInfo &TII) {
MachineFunction::iterator MFEnd = VRM->getMachineFunction().end();
for (LocMap::const_iterator I = locInts.begin(); I.valid();) {
SlotIndex Start = I.start();
SlotIndex Stop = I.stop();
unsigned LocNo = I.value();
DEBUG(dbgs() << "\t[" << Start << ';' << Stop << "):" << LocNo);
MachineFunction::iterator MBB = LIS.getMBBFromIndex(Start);
SlotIndex MBBEnd = LIS.getMBBEndIdx(MBB);
DEBUG(dbgs() << " BB#" << MBB->getNumber() << '-' << MBBEnd);
insertDebugValue(MBB, Start, LocNo, LIS, TII);
// This interval may span multiple basic blocks.
// Insert a DBG_VALUE into each one.
while(Stop > MBBEnd) {
// Move to the next block.
Start = MBBEnd;
if (++MBB == MFEnd)
break;
MBBEnd = LIS.getMBBEndIdx(MBB);
DEBUG(dbgs() << " BB#" << MBB->getNumber() << '-' << MBBEnd);
insertDebugValue(MBB, Start, LocNo, LIS, TII);
}
DEBUG(dbgs() << '\n');
if (MBB == MFEnd)
break;
++I;
if (Stop == MBBEnd)
continue;
// The current interval ends before MBB.
// Insert a kill if there is a gap.
if (!I.valid() || I.start() > Stop)
insertDebugKill(MBB, Stop, LIS, TII);
}
}
void LDVImpl::emitDebugValues(VirtRegMap *VRM) {
DEBUG(dbgs() << "********** EMITTING LIVE DEBUG VARIABLES **********\n");
const TargetInstrInfo *TII = MF->getTarget().getInstrInfo();
for (unsigned i = 0, e = userValues.size(); i != e; ++i) {
userValues[i]->rewriteLocations(*VRM, *TRI);
userValues[i]->emitDebugValues(VRM, *LIS, *TII);
}
}
void LiveDebugVariables::emitDebugValues(VirtRegMap *VRM) {
if (pImpl)
static_cast<LDVImpl*>(pImpl)->emitDebugValues(VRM);
}
#ifndef NDEBUG
void LiveDebugVariables::dump() {
if (pImpl)
static_cast<LDVImpl*>(pImpl)->print(dbgs());
}
#endif