void UserValue::coalesceLocation(unsigned LocNo) { unsigned KeepLoc = 0; for (unsigned e = locations.size(); KeepLoc != e; ++KeepLoc) { if (KeepLoc == LocNo) continue; if (locations[KeepLoc].isIdenticalTo(locations[LocNo])) break; } // No matches. if (KeepLoc == locations.size()) return; // Keep the smaller location, erase the larger one. unsigned EraseLoc = LocNo; if (KeepLoc > EraseLoc) std::swap(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. } }
void UserValue::computeIntervals(MachineRegisterInfo &MRI, 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())); // Extend all defs, and possibly add new ones along the way. for (unsigned i = 0; i != Defs.size(); ++i) { SlotIndex Idx = Defs[i].first; unsigned LocNo = Defs[i].second; const MachineOperand &Loc = locations[LocNo]; // 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); 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); } // Finally, erase all the undefs. for (LocMap::iterator I = locInts.begin(); I.valid();) if (I.value() == ~0u) I.erase(); else ++I; }
void UserValue::extendDef(SlotIndex Idx, unsigned LocNo, LiveRange *LR, const VNInfo *VNI, SmallVectorImpl<SlotIndex> *Kills, 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); SlotIndex Stop = LIS.getMBBEndIdx(MBB); LocMap::iterator I = locInts.find(Start); // Limit to VNI's live range. bool ToEnd = true; if (LR && VNI) { LiveInterval::Segment *Segment = LR->getSegmentContaining(Start); if (!Segment || Segment->valno != VNI) { if (Kills) Kills->push_back(Start); continue; } if (Segment->end < Stop) Stop = Segment->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; // Limited by VNI's live range. else if (!ToEnd && Kills) Kills->push_back(Stop); 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) { MachineBasicBlock *MBB = Children[i]->getBlock(); if (UVS.dominates(MBB)) Todo.push_back(LIS.getMBBStartIdx(MBB)); } } while (!Todo.empty()); }
void UserValue::computeIntervals(MachineRegisterInfo &MRI, const TargetRegisterInfo &TRI, LiveIntervals &LIS, MachineDominatorTree &MDT, UserValueScopes &UVS) { 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())); // Extend all defs, and possibly add new ones along the way. for (unsigned i = 0; i != Defs.size(); ++i) { SlotIndex Idx = Defs[i].first; 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 (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, 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); LiveRange *LR = &LIS.getRegUnit(Unit); const VNInfo *VNI = LR->getVNInfoAt(Idx); // Don't track copies from physregs, it is too expensive. extendDef(Idx, LocNo, LR, VNI, 0, LIS, MDT, UVS); } // Finally, erase all the undefs. for (LocMap::iterator I = locInts.begin(); I.valid();) if (I.value() == ~0u) I.erase(); else ++I; }
/// We only propagate DBG_VALUES locally here. LiveDebugValues performs a /// data-flow analysis to propagate them beyond basic block boundaries. void UserValue::extendDef(SlotIndex Idx, unsigned LocNo, LiveRange *LR, const VNInfo *VNI, SmallVectorImpl<SlotIndex> *Kills, LiveIntervals &LIS, MachineDominatorTree &MDT, UserValueScopes &UVS) { SlotIndex Start = Idx; MachineBasicBlock *MBB = LIS.getMBBFromIndex(Start); SlotIndex Stop = LIS.getMBBEndIdx(MBB); LocMap::iterator I = locInts.find(Start); // Limit to VNI's live range. bool ToEnd = true; if (LR && VNI) { LiveInterval::Segment *Segment = LR->getSegmentContaining(Start); if (!Segment || Segment->valno != VNI) { if (Kills) Kills->push_back(Start); return; } if (Segment->end < Stop) { Stop = Segment->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) return; // 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; } // Limited by VNI's live range. else if (!ToEnd && Kills) Kills->push_back(Stop); if (Start < Stop) I.insert(Start, Stop, LocNo); }
void UserValue::addDefsFromCopies(LiveInterval *LI, unsigned LocNo, const SmallVectorImpl<SlotIndex> &Kills, SmallVectorImpl<std::pair<SlotIndex, unsigned> > &NewDefs, MachineRegisterInfo &MRI, LiveIntervals &LIS) { if (Kills.empty()) return; // Don't track copies from physregs, there are too many uses. if (!TargetRegisterInfo::isVirtualRegister(LI->reg)) return; // Collect all the (vreg, valno) pairs that are copies of LI. SmallVector<std::pair<LiveInterval*, const VNInfo*>, 8> CopyValues; for (MachineRegisterInfo::use_nodbg_iterator UI = MRI.use_nodbg_begin(LI->reg), UE = MRI.use_nodbg_end(); UI != UE; ++UI) { // Copies of the full value. if (UI.getOperand().getSubReg() || !UI->isCopy()) continue; MachineInstr *MI = &*UI; unsigned DstReg = MI->getOperand(0).getReg(); // Don't follow copies to physregs. These are usually setting up call // arguments, and the argument registers are always call clobbered. We are // better off in the source register which could be a callee-saved register, // or it could be spilled. if (!TargetRegisterInfo::isVirtualRegister(DstReg)) continue; // 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.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.getRegSlot()); assert(DstVNI && DstVNI->def == Idx.getRegSlot() && "Bad copy value"); CopyValues.push_back(std::make_pair(DstLI, DstVNI)); } if (CopyValues.empty()) return; DEBUG(dbgs() << "Got " << CopyValues.size() << " copies of " << *LI << '\n'); // Try to add defs of the copied values for each kill point. for (unsigned i = 0, e = Kills.size(); i != e; ++i) { SlotIndex Idx = Kills[i]; for (unsigned j = 0, e = CopyValues.size(); j != e; ++j) { LiveInterval *DstLI = CopyValues[j].first; const VNInfo *DstVNI = CopyValues[j].second; if (DstLI->getVNInfoAt(Idx) != DstVNI) continue; // Check that there isn't already a def at Idx LocMap::iterator I = locInts.find(Idx); if (I.valid() && I.start() <= Idx) continue; DEBUG(dbgs() << "Kill at " << Idx << " covered by valno #" << DstVNI->id << " in " << *DstLI << '\n'); MachineInstr *CopyMI = LIS.getInstructionFromIndex(DstVNI->def); assert(CopyMI && CopyMI->isCopy() && "Bad copy value"); unsigned LocNo = getLocationNo(CopyMI->getOperand(0)); I.insert(Idx, Idx.getNextSlot(), LocNo); NewDefs.push_back(std::make_pair(Idx, LocNo)); break; } } }
void UserValue::computeIntervals(MachineRegisterInfo &MRI, const TargetRegisterInfo &TRI, LiveIntervals &LIS, LexicalScopes &LS) { 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() != UndefLocNo) Defs.push_back(std::make_pair(I.start(), I.value())); // Extend all defs, and possibly add new ones along the way. for (unsigned i = 0; i != Defs.size(); ++i) { SlotIndex Idx = Defs[i].first; unsigned LocNo = Defs[i].second; const MachineOperand &Loc = locations[LocNo]; if (!Loc.isReg()) { extendDef(Idx, LocNo, nullptr, nullptr, nullptr, LIS); continue; } // Register locations are constrained to where the register value is live. if (TargetRegisterInfo::isVirtualRegister(Loc.getReg())) { LiveInterval *LI = nullptr; const VNInfo *VNI = nullptr; 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); 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); LiveRange *LR = &LIS.getRegUnit(Unit); const VNInfo *VNI = LR->getVNInfoAt(Idx); // Don't track copies from physregs, it is too expensive. extendDef(Idx, LocNo, LR, VNI, nullptr, LIS); } // Erase all the undefs. for (LocMap::iterator I = locInts.begin(); I.valid();) if (I.value() == UndefLocNo) I.erase(); else ++I; // The computed intervals may extend beyond the range of the debug // location's lexical scope. In this case, splitting of an interval // can result in an interval outside of the scope being created, // causing extra unnecessary DBG_VALUEs to be emitted. To prevent // this, trim the intervals to the lexical scope. LexicalScope *Scope = LS.findLexicalScope(dl); if (!Scope) return; SlotIndex PrevEnd; LocMap::iterator I = locInts.begin(); // Iterate over the lexical scope ranges. Each time round the loop // we check the intervals for overlap with the end of the previous // range and the start of the next. The first range is handled as // a special case where there is no PrevEnd. for (const InsnRange &Range : Scope->getRanges()) { SlotIndex RStart = LIS.getInstructionIndex(*Range.first); SlotIndex REnd = LIS.getInstructionIndex(*Range.second); // At the start of each iteration I has been advanced so that // I.stop() >= PrevEnd. Check for overlap. if (PrevEnd && I.start() < PrevEnd) { SlotIndex IStop = I.stop(); unsigned LocNo = I.value(); // Stop overlaps previous end - trim the end of the interval to // the scope range. I.setStopUnchecked(PrevEnd); ++I; // If the interval also overlaps the start of the "next" (i.e. // current) range create a new interval for the remainder (which // may be further trimmed). if (RStart < IStop) I.insert(RStart, IStop, LocNo); } // Advance I so that I.stop() >= RStart, and check for overlap. I.advanceTo(RStart); if (!I.valid()) return; if (I.start() < RStart) { // Interval start overlaps range - trim to the scope range. I.setStartUnchecked(RStart); // Remember that this interval was trimmed. trimmedDefs.insert(RStart); } // The end of a lexical scope range is the last instruction in the // range. To convert to an interval we need the index of the // instruction after it. REnd = REnd.getNextIndex(); // Advance I to first interval outside current range. I.advanceTo(REnd); if (!I.valid()) return; PrevEnd = REnd; } // Check for overlap with end of final range. if (PrevEnd && I.start() < PrevEnd) I.setStopUnchecked(PrevEnd); }