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-rw-r--r--llvm/lib/CodeGen/LiveDebugVariables.cpp84
1 files changed, 64 insertions, 20 deletions
diff --git a/llvm/lib/CodeGen/LiveDebugVariables.cpp b/llvm/lib/CodeGen/LiveDebugVariables.cpp
index 2325341..553ceb7 100644
--- a/llvm/lib/CodeGen/LiveDebugVariables.cpp
+++ b/llvm/lib/CodeGen/LiveDebugVariables.cpp
@@ -145,6 +145,14 @@ using LocMap = IntervalMap<SlotIndex, DbgVariableValue, 4>;
/// Non-spilled locations are not added to the map.
using SpillOffsetMap = DenseMap<unsigned, unsigned>;
+/// Cache to save the location where it can be used as the starting
+/// position as input for calling MachineBasicBlock::SkipPHIsLabelsAndDebug.
+/// This is to prevent MachineBasicBlock::SkipPHIsLabelsAndDebug from
+/// repeatedly searching the same set of PHIs/Labels/Debug instructions
+/// if it is called many times for the same block.
+using BlockSkipInstsMap =
+ DenseMap<MachineBasicBlock *, MachineBasicBlock::iterator>;
+
namespace {
class LDVImpl;
@@ -181,7 +189,8 @@ class UserValue {
SlotIndex StopIdx, DbgVariableValue DbgValue,
bool Spilled, unsigned SpillOffset, LiveIntervals &LIS,
const TargetInstrInfo &TII,
- const TargetRegisterInfo &TRI);
+ const TargetRegisterInfo &TRI,
+ BlockSkipInstsMap &BBSkipInstsMap);
/// Replace OldLocNo ranges with NewRegs ranges where NewRegs
/// is live. Returns true if any changes were made.
@@ -348,7 +357,8 @@ public:
void emitDebugValues(VirtRegMap *VRM, LiveIntervals &LIS,
const TargetInstrInfo &TII,
const TargetRegisterInfo &TRI,
- const SpillOffsetMap &SpillOffsets);
+ const SpillOffsetMap &SpillOffsets,
+ BlockSkipInstsMap &BBSkipInstsMap);
/// Return DebugLoc of this UserValue.
DebugLoc getDebugLoc() { return dl;}
@@ -365,7 +375,8 @@ class UserLabel {
/// Insert a DBG_LABEL into MBB at Idx.
void insertDebugLabel(MachineBasicBlock *MBB, SlotIndex Idx,
- LiveIntervals &LIS, const TargetInstrInfo &TII);
+ LiveIntervals &LIS, const TargetInstrInfo &TII,
+ BlockSkipInstsMap &BBSkipInstsMap);
public:
/// Create a new UserLabel.
@@ -379,7 +390,8 @@ public:
}
/// Recreate DBG_LABEL instruction from data structures.
- void emitDebugLabel(LiveIntervals &LIS, const TargetInstrInfo &TII);
+ void emitDebugLabel(LiveIntervals &LIS, const TargetInstrInfo &TII,
+ BlockSkipInstsMap &BBSkipInstsMap);
/// Return DebugLoc of this UserLabel.
DebugLoc getDebugLoc() { return dl; }
@@ -1282,8 +1294,8 @@ void UserValue::rewriteLocations(VirtRegMap &VRM, const MachineFunction &MF,
/// Find an iterator for inserting a DBG_VALUE instruction.
static MachineBasicBlock::iterator
-findInsertLocation(MachineBasicBlock *MBB, SlotIndex Idx,
- LiveIntervals &LIS) {
+findInsertLocation(MachineBasicBlock *MBB, SlotIndex Idx, LiveIntervals &LIS,
+ BlockSkipInstsMap &BBSkipInstsMap) {
SlotIndex Start = LIS.getMBBStartIdx(MBB);
Idx = Idx.getBaseIndex();
@@ -1292,7 +1304,29 @@ findInsertLocation(MachineBasicBlock *MBB, SlotIndex Idx,
while (!(MI = LIS.getInstructionFromIndex(Idx))) {
// We've reached the beginning of MBB.
if (Idx == Start) {
- MachineBasicBlock::iterator I = MBB->SkipPHIsLabelsAndDebug(MBB->begin());
+ // Retrieve the last PHI/Label/Debug location found when calling
+ // SkipPHIsLabelsAndDebug last time. Start searching from there.
+ //
+ // Note the iterator kept in BBSkipInstsMap is one step back based
+ // on the iterator returned by SkipPHIsLabelsAndDebug last time.
+ // One exception is when SkipPHIsLabelsAndDebug returns MBB->begin(),
+ // BBSkipInstsMap won't save it. This is to consider the case that
+ // new instructions may be inserted at the beginning of MBB after
+ // last call of SkipPHIsLabelsAndDebug. If we save MBB->begin() in
+ // BBSkipInstsMap, after new non-phi/non-label/non-debug instructions
+ // are inserted at the beginning of the MBB, the iterator in
+ // BBSkipInstsMap won't point to the beginning of the MBB anymore.
+ // Therefore The next search in SkipPHIsLabelsAndDebug will skip those
+ // newly added instructions and that is unwanted.
+ MachineBasicBlock::iterator BeginIt;
+ auto MapIt = BBSkipInstsMap.find(MBB);
+ if (MapIt == BBSkipInstsMap.end())
+ BeginIt = MBB->begin();
+ else
+ BeginIt = std::next(MapIt->second);
+ auto I = MBB->SkipPHIsLabelsAndDebug(BeginIt);
+ if (I != BeginIt)
+ BBSkipInstsMap[MBB] = std::prev(I);
return I;
}
Idx = Idx.getPrevIndex();
@@ -1332,11 +1366,13 @@ void UserValue::insertDebugValue(MachineBasicBlock *MBB, SlotIndex StartIdx,
SlotIndex StopIdx, DbgVariableValue DbgValue,
bool Spilled, unsigned SpillOffset,
LiveIntervals &LIS, const TargetInstrInfo &TII,
- const TargetRegisterInfo &TRI) {
+ const TargetRegisterInfo &TRI,
+ BlockSkipInstsMap &BBSkipInstsMap) {
SlotIndex MBBEndIdx = LIS.getMBBEndIdx(&*MBB);
// Only search within the current MBB.
StopIdx = (MBBEndIdx < StopIdx) ? MBBEndIdx : StopIdx;
- MachineBasicBlock::iterator I = findInsertLocation(MBB, StartIdx, LIS);
+ MachineBasicBlock::iterator I =
+ findInsertLocation(MBB, StartIdx, LIS, BBSkipInstsMap);
// Undef values don't exist in locations so create new "noreg" register MOs
// for them. See getLocationNo().
MachineOperand MO =
@@ -1382,9 +1418,10 @@ void UserValue::insertDebugValue(MachineBasicBlock *MBB, SlotIndex StartIdx,
}
void UserLabel::insertDebugLabel(MachineBasicBlock *MBB, SlotIndex Idx,
- LiveIntervals &LIS,
- const TargetInstrInfo &TII) {
- MachineBasicBlock::iterator I = findInsertLocation(MBB, Idx, LIS);
+ LiveIntervals &LIS, const TargetInstrInfo &TII,
+ BlockSkipInstsMap &BBSkipInstsMap) {
+ MachineBasicBlock::iterator I =
+ findInsertLocation(MBB, Idx, LIS, BBSkipInstsMap);
++NumInsertedDebugLabels;
BuildMI(*MBB, I, getDebugLoc(), TII.get(TargetOpcode::DBG_LABEL))
.addMetadata(Label);
@@ -1393,7 +1430,8 @@ void UserLabel::insertDebugLabel(MachineBasicBlock *MBB, SlotIndex Idx,
void UserValue::emitDebugValues(VirtRegMap *VRM, LiveIntervals &LIS,
const TargetInstrInfo &TII,
const TargetRegisterInfo &TRI,
- const SpillOffsetMap &SpillOffsets) {
+ const SpillOffsetMap &SpillOffsets,
+ BlockSkipInstsMap &BBSkipInstsMap) {
MachineFunction::iterator MFEnd = VRM->getMachineFunction().end();
for (LocMap::const_iterator I = locInts.begin(); I.valid();) {
@@ -1418,7 +1456,7 @@ void UserValue::emitDebugValues(VirtRegMap *VRM, LiveIntervals &LIS,
LLVM_DEBUG(dbgs() << ' ' << printMBBReference(*MBB) << '-' << MBBEnd);
insertDebugValue(&*MBB, Start, Stop, DbgValue, Spilled, SpillOffset, LIS,
- TII, TRI);
+ TII, TRI, BBSkipInstsMap);
// This interval may span multiple basic blocks.
// Insert a DBG_VALUE into each one.
while (Stop > MBBEnd) {
@@ -1429,7 +1467,7 @@ void UserValue::emitDebugValues(VirtRegMap *VRM, LiveIntervals &LIS,
MBBEnd = LIS.getMBBEndIdx(&*MBB);
LLVM_DEBUG(dbgs() << ' ' << printMBBReference(*MBB) << '-' << MBBEnd);
insertDebugValue(&*MBB, Start, Stop, DbgValue, Spilled, SpillOffset, LIS,
- TII, TRI);
+ TII, TRI, BBSkipInstsMap);
}
LLVM_DEBUG(dbgs() << '\n');
if (MBB == MFEnd)
@@ -1439,12 +1477,13 @@ void UserValue::emitDebugValues(VirtRegMap *VRM, LiveIntervals &LIS,
}
}
-void UserLabel::emitDebugLabel(LiveIntervals &LIS, const TargetInstrInfo &TII) {
+void UserLabel::emitDebugLabel(LiveIntervals &LIS, const TargetInstrInfo &TII,
+ BlockSkipInstsMap &BBSkipInstsMap) {
LLVM_DEBUG(dbgs() << "\t" << loc);
MachineFunction::iterator MBB = LIS.getMBBFromIndex(loc)->getIterator();
LLVM_DEBUG(dbgs() << ' ' << printMBBReference(*MBB));
- insertDebugLabel(&*MBB, loc, LIS, TII);
+ insertDebugLabel(&*MBB, loc, LIS, TII, BBSkipInstsMap);
LLVM_DEBUG(dbgs() << '\n');
}
@@ -1453,17 +1492,20 @@ void LDVImpl::emitDebugValues(VirtRegMap *VRM) {
LLVM_DEBUG(dbgs() << "********** EMITTING LIVE DEBUG VARIABLES **********\n");
if (!MF)
return;
+
+ BlockSkipInstsMap BBSkipInstsMap;
const TargetInstrInfo *TII = MF->getSubtarget().getInstrInfo();
SpillOffsetMap SpillOffsets;
for (auto &userValue : userValues) {
LLVM_DEBUG(userValue->print(dbgs(), TRI));
userValue->rewriteLocations(*VRM, *MF, *TII, *TRI, SpillOffsets);
- userValue->emitDebugValues(VRM, *LIS, *TII, *TRI, SpillOffsets);
+ userValue->emitDebugValues(VRM, *LIS, *TII, *TRI, SpillOffsets,
+ BBSkipInstsMap);
}
LLVM_DEBUG(dbgs() << "********** EMITTING LIVE DEBUG LABELS **********\n");
for (auto &userLabel : userLabels) {
LLVM_DEBUG(userLabel->print(dbgs(), TRI));
- userLabel->emitDebugLabel(*LIS, *TII);
+ userLabel->emitDebugLabel(*LIS, *TII, BBSkipInstsMap);
}
LLVM_DEBUG(dbgs() << "********** EMITTING INSTR REFERENCES **********\n");
@@ -1475,7 +1517,8 @@ void LDVImpl::emitDebugValues(VirtRegMap *VRM) {
for (auto &P : StashedInstrReferences) {
const SlotIndex &Idx = P.first;
auto *MBB = Slots->getMBBFromIndex(Idx);
- MachineBasicBlock::iterator insertPos = findInsertLocation(MBB, Idx, *LIS);
+ MachineBasicBlock::iterator insertPos =
+ findInsertLocation(MBB, Idx, *LIS, BBSkipInstsMap);
for (auto &Stashed : P.second) {
auto MIB = BuildMI(*MF, std::get<4>(Stashed), RefII);
MIB.addImm(std::get<0>(Stashed));
@@ -1488,6 +1531,7 @@ void LDVImpl::emitDebugValues(VirtRegMap *VRM) {
}
EmitDone = true;
+ BBSkipInstsMap.clear();
}
void LiveDebugVariables::emitDebugValues(VirtRegMap *VRM) {
generated by cgit v1.1 at 2025-09-29 08:29:23 +0000