#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/ADT/Statistic.h"
+#include "llvm/CodeGen/LexicalScopes.h"
#include "llvm/CodeGen/LiveIntervalAnalysis.h"
#include "llvm/CodeGen/MachineDominators.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/CodeGen/MachineRegisterInfo.h"
#include "llvm/CodeGen/Passes.h"
+#include "llvm/CodeGen/VirtRegMap.h"
+#include "llvm/Constants.h"
+#include "llvm/DebugInfo.h"
+#include "llvm/Metadata.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"
+#include "llvm/Value.h"
using namespace llvm;
EnableLDV("live-debug-variables", cl::init(true),
cl::desc("Enable the live debug variables pass"), cl::Hidden);
+STATISTIC(NumInsertedDebugValues, "Number of DBG_VALUEs inserted");
char LiveDebugVariables::ID = 0;
INITIALIZE_PASS_BEGIN(LiveDebugVariables, "livedebugvars",
/// LocMap - Map of where a user value is live, and its location.
typedef IntervalMap<SlotIndex, unsigned, 4> LocMap;
+namespace {
+/// UserValueScopes - Keeps track of lexical scopes associated with an
+/// user value's source location.
+class UserValueScopes {
+ DebugLoc DL;
+ LexicalScopes &LS;
+ SmallPtrSet<const MachineBasicBlock *, 4> LBlocks;
+
+public:
+ UserValueScopes(DebugLoc D, LexicalScopes &L) : DL(D), LS(L) {}
+
+ /// dominates - Return true if current scope dominates at least one machine
+ /// instruction in a given machine basic block.
+ bool dominates(MachineBasicBlock *MBB) {
+ if (LBlocks.empty())
+ LS.getMachineBasicBlocks(DL, LBlocks);
+ if (LBlocks.count(MBB) != 0 || LS.dominates(DL, MBB))
+ return true;
+ return false;
+ }
+};
+} // end anonymous namespace
+
/// 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
/// getNext - Return the next UserValue in the equivalence class.
UserValue *getNext() const { return next; }
- /// match - Does this UserValue match the aprameters?
+ /// match - Does this UserValue match the parameters?
bool match(const MDNode *Var, unsigned Offset) const {
return Var == variable && Offset == offset;
}
LocMap::iterator I = locInts.find(Idx);
if (!I.valid() || I.start() != Idx)
I.insert(Idx, Idx.getNextSlot(), getLocationNo(LocMO));
+ else
+ // A later DBG_VALUE at the same SlotIndex overrides the old location.
+ I.setValue(getLocationNo(LocMO));
}
/// extendDef - Extend the current definition as far as possible down the
void extendDef(SlotIndex Idx, unsigned LocNo,
LiveInterval *LI, const VNInfo *VNI,
SmallVectorImpl<SlotIndex> *Kills,
- LiveIntervals &LIS, MachineDominatorTree &MDT);
+ LiveIntervals &LIS, MachineDominatorTree &MDT,
+ UserValueScopes &UVS);
/// addDefsFromCopies - The value in LI/LocNo may be copies to other
/// registers. Determine if any of the copies are available at the kill
/// computeIntervals - Compute the live intervals of all locations after
/// collecting all their def points.
- void computeIntervals(MachineRegisterInfo &MRI,
- LiveIntervals &LIS, MachineDominatorTree &MDT);
+ void computeIntervals(MachineRegisterInfo &MRI, const TargetRegisterInfo &TRI,
+ LiveIntervals &LIS, MachineDominatorTree &MDT,
+ UserValueScopes &UVS);
/// renameRegister - Update locations to rewrite OldReg as NewReg:SubIdx.
void renameRegister(unsigned OldReg, unsigned NewReg, unsigned SubIdx,
/// Only first one needs DebugLoc to identify variable's lexical scope
/// in source file.
DebugLoc findDebugLoc();
+
+ /// getDebugLoc - Return DebugLoc of this UserValue.
+ DebugLoc getDebugLoc() { return dl;}
void print(raw_ostream&, const TargetMachine*);
};
} // namespace
LocMap::Allocator allocator;
MachineFunction *MF;
LiveIntervals *LIS;
+ LexicalScopes LS;
MachineDominatorTree *MDT;
const TargetRegisterInfo *TRI;
} // namespace
void UserValue::print(raw_ostream &OS, const TargetMachine *TM) {
- if (const MDString *MDS = dyn_cast<MDString>(variable->getOperand(2)))
- OS << "!\"" << MDS->getString() << "\"\t";
+ DIVariable DV(variable);
+ OS << "!\"";
+ DV.printExtendedName(OS);
+ OS << "\"\t";
if (offset)
OS << '+' << offset;
for (LocMap::const_iterator I = locInts.begin(); I.valid(); ++I) {
// 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();
+ LIS->getInstructionIndex(llvm::prior(MBBI)).getRegSlot();
// Handle consecutive DBG_VALUE instructions with the same slot index.
do {
if (handleDebugValue(MBBI, Idx)) {
void UserValue::extendDef(SlotIndex Idx, unsigned LocNo,
LiveInterval *LI, const VNInfo *VNI,
SmallVectorImpl<SlotIndex> *Kills,
- LiveIntervals &LIS, MachineDominatorTree &MDT) {
+ LiveIntervals &LIS, MachineDominatorTree &MDT,
+ UserValueScopes &UVS) {
SmallVector<SlotIndex, 16> Todo;
Todo.push_back(Idx);
-
do {
SlotIndex Start = Todo.pop_back_val();
MachineBasicBlock *MBB = LIS.getMBBFromIndex(Start);
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()));
+ for (unsigned i = 0, e = Children.size(); i != e; ++i) {
+ MachineBasicBlock *MBB = Children[i]->getBlock();
+ if (UVS.dominates(MBB))
+ Todo.push_back(LIS.getMBBStartIdx(MBB));
+ }
} while (!Todo.empty());
}
// Is LocNo extended to reach this copy? If not, another def may be blocking
// it, or we are looking at a wrong value of LI.
SlotIndex Idx = LIS.getInstructionIndex(MI);
- LocMap::iterator I = locInts.find(Idx.getUseIndex());
+ LocMap::iterator I = locInts.find(Idx.getRegSlot(true));
if (!I.valid() || I.value() != LocNo)
continue;
if (!LIS.hasInterval(DstReg))
continue;
LiveInterval *DstLI = &LIS.getInterval(DstReg);
- const VNInfo *DstVNI = DstLI->getVNInfoAt(Idx.getDefIndex());
- assert(DstVNI && DstVNI->def == Idx.getDefIndex() && "Bad copy value");
+ const VNInfo *DstVNI = DstLI->getVNInfoAt(Idx.getRegSlot());
+ assert(DstVNI && DstVNI->def == Idx.getRegSlot() && "Bad copy value");
CopyValues.push_back(std::make_pair(DstLI, DstVNI));
}
void
UserValue::computeIntervals(MachineRegisterInfo &MRI,
+ const TargetRegisterInfo &TRI,
LiveIntervals &LIS,
- MachineDominatorTree &MDT) {
+ MachineDominatorTree &MDT,
+ UserValueScopes &UVS) {
SmallVector<std::pair<SlotIndex, unsigned>, 16> Defs;
// Collect all defs to be extended (Skipping undefs).
unsigned LocNo = Defs[i].second;
const MachineOperand &Loc = locations[LocNo];
+ if (!Loc.isReg()) {
+ extendDef(Idx, LocNo, 0, 0, 0, LIS, MDT, UVS);
+ continue;
+ }
+
// Register locations are constrained to where the register value is live.
- if (Loc.isReg() && LIS.hasInterval(Loc.getReg())) {
- LiveInterval *LI = &LIS.getInterval(Loc.getReg());
- const VNInfo *VNI = LI->getVNInfoAt(Idx);
+ if (TargetRegisterInfo::isVirtualRegister(Loc.getReg())) {
+ LiveInterval *LI = 0;
+ const VNInfo *VNI = 0;
+ if (LIS.hasInterval(Loc.getReg())) {
+ LI = &LIS.getInterval(Loc.getReg());
+ VNI = LI->getVNInfoAt(Idx);
+ }
SmallVector<SlotIndex, 16> Kills;
- extendDef(Idx, LocNo, LI, VNI, &Kills, LIS, MDT);
- addDefsFromCopies(LI, LocNo, Kills, Defs, MRI, LIS);
- } else
- extendDef(Idx, LocNo, 0, 0, 0, LIS, MDT);
+ extendDef(Idx, LocNo, LI, VNI, &Kills, LIS, MDT, UVS);
+ if (LI)
+ addDefsFromCopies(LI, LocNo, Kills, Defs, MRI, LIS);
+ continue;
+ }
+
+ // For physregs, use the live range of the first regunit as a guide.
+ unsigned Unit = *MCRegUnitIterator(Loc.getReg(), &TRI);
+ LiveInterval *LI = &LIS.getRegUnit(Unit);
+ const VNInfo *VNI = LI->getVNInfoAt(Idx);
+ // Don't track copies from physregs, it is too expensive.
+ extendDef(Idx, LocNo, LI, VNI, 0, LIS, MDT, UVS);
}
// Finally, erase all the undefs.
void LDVImpl::computeIntervals() {
for (unsigned i = 0, e = userValues.size(); i != e; ++i) {
- userValues[i]->computeIntervals(MF->getRegInfo(), *LIS, *MDT);
+ UserValueScopes UVS(userValues[i]->getDebugLoc(), LS);
+ userValues[i]->computeIntervals(MF->getRegInfo(), *TRI, *LIS, *MDT, UVS);
userValues[i]->mapVirtRegs(this);
}
}
MDT = &pass.getAnalysis<MachineDominatorTree>();
TRI = mf.getTarget().getRegisterInfo();
clear();
+ LS.initialize(mf);
DEBUG(dbgs() << "********** COMPUTING LIVE DEBUG VARIABLES: "
- << ((Value*)mf.getFunction())->getName()
- << " **********\n");
+ << mf.getName() << " **********\n");
bool Changed = collectDebugValues(mf);
computeIntervals();
DEBUG(print(dbgs()));
+ LS.releaseMemory();
return Changed;
}
if (TargetRegisterInfo::isVirtualRegister(NewReg))
mapVirtReg(NewReg, UV);
- virtRegToEqClass.erase(OldReg);
+ if (OldReg != NewReg)
+ virtRegToEqClass.erase(OldReg);
do {
UV->renameRegister(OldReg, NewReg, SubIdx, TRI);
bool
UserValue::splitRegister(unsigned OldReg, ArrayRef<LiveInterval*> NewRegs) {
bool DidChange = false;
- for (unsigned LocNo = 0, E = locations.size(); LocNo != E; ++LocNo) {
+ // Split locations referring to OldReg. Iterate backwards so splitLocation can
+ // safely erase unused locations.
+ for (unsigned i = locations.size(); i ; --i) {
+ unsigned LocNo = i-1;
const MachineOperand *Loc = &locations[LocNo];
if (!Loc->isReg() || Loc->getReg() != OldReg)
continue;
unsigned VirtReg = Loc.getReg();
if (VRM.isAssignedReg(VirtReg) &&
TargetRegisterInfo::isPhysicalRegister(VRM.getPhys(VirtReg))) {
+ // This can create a %noreg operand in rare cases when the sub-register
+ // index is no longer available. That means the user value is in a
+ // non-existent sub-register, and %noreg is exactly what we want.
Loc.substPhysReg(VRM.getPhys(VirtReg), TRI);
- } else if (VRM.getStackSlot(VirtReg) != VirtRegMap::NO_STACK_SLOT &&
- VRM.isSpillSlotUsed(VRM.getStackSlot(VirtReg))) {
+ } else if (VRM.getStackSlot(VirtReg) != VirtRegMap::NO_STACK_SLOT) {
// FIXME: Translate SubIdx to a stackslot offset.
Loc = MachineOperand::CreateFI(VRM.getStackSlot(VirtReg));
} else {
}
// Don't insert anything after the first terminator, though.
- return MI->getDesc().isTerminator() ? MBB->getFirstTerminator() :
- llvm::next(MachineBasicBlock::iterator(MI));
+ return MI->isTerminator() ? MBB->getFirstTerminator() :
+ llvm::next(MachineBasicBlock::iterator(MI));
}
DebugLoc UserValue::findDebugLoc() {
const TargetInstrInfo &TII) {
MachineBasicBlock::iterator I = findInsertLocation(MBB, Idx, LIS);
MachineOperand &Loc = locations[LocNo];
+ ++NumInsertedDebugValues;
// Frame index locations may require a target callback.
if (Loc.isFI()) {
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) {
DEBUG(dbgs() << "********** EMITTING LIVE DEBUG VARIABLES **********\n");
const TargetInstrInfo *TII = MF->getTarget().getInstrInfo();
for (unsigned i = 0, e = userValues.size(); i != e; ++i) {
+ DEBUG(userValues[i]->print(dbgs(), &MF->getTarget()));
userValues[i]->rewriteLocations(*VRM, *TRI);
userValues[i]->emitDebugValues(VRM, *LIS, *TII);
}