#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/Support/CommandLine.h"
#include "llvm/Support/Debug.h"
/// held by the same virtual register. The equivalence class is the transitive
/// closure of that relation.
namespace {
+class LDVImpl;
class UserValue {
const MDNode *variable; ///< The debug info variable we are part of.
unsigned offset; ///< Byte offset into variable.
/// getLocationNo - Return the location number that matches Loc.
unsigned getLocationNo(const MachineOperand &LocMO) {
- if (LocMO.isReg() && LocMO.getReg() == 0)
- return ~0u;
- for (unsigned i = 0, e = locations.size(); i != e; ++i)
- if (LocMO.isIdenticalTo(locations[i]))
- return i;
+ if (LocMO.isReg()) {
+ if (LocMO.getReg() == 0)
+ return ~0u;
+ // For register locations we dont care about use/def and other flags.
+ for (unsigned i = 0, e = locations.size(); i != e; ++i)
+ if (locations[i].isReg() &&
+ locations[i].getReg() == LocMO.getReg() &&
+ locations[i].getSubReg() == LocMO.getSubReg())
+ return i;
+ } else
+ for (unsigned i = 0, e = locations.size(); i != e; ++i)
+ if (LocMO.isIdenticalTo(locations[i]))
+ return i;
locations.push_back(LocMO);
// We are storing a MachineOperand outside a MachineInstr.
locations.back().clearParent();
+ // Don't store def operands.
+ if (locations.back().isReg())
+ locations.back().setIsUse();
return locations.size() - 1;
}
+ /// mapVirtRegs - Ensure that all virtual register locations are mapped.
+ void mapVirtRegs(LDVImpl *LDV);
+
/// addDef - Add a definition point to this value.
void addDef(SlotIndex Idx, const MachineOperand &LocMO) {
// Add a singular (Idx,Idx) -> Loc mapping.
/// 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.
+ /// End points where VNI is no longer live are added to Kills.
/// @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 Kills Append end points of VNI's live range to Kills.
/// @param LIS Live intervals analysis.
/// @param MDT Dominator tree.
void extendDef(SlotIndex Idx, unsigned LocNo,
LiveInterval *LI, const VNInfo *VNI,
+ SmallVectorImpl<SlotIndex> *Kills,
LiveIntervals &LIS, MachineDominatorTree &MDT);
+ /// addDefsFromCopies - The value in LI/LocNo may be copies to other
+ /// registers. Determine if any of the copies are available at the kill
+ /// points, and add defs if possible.
+ /// @param LI Scan for copies of the value in LI->reg.
+ /// @param LocNo Location number of LI->reg.
+ /// @param Kills Points where the range of LocNo could be extended.
+ /// @param NewDefs Append (Idx, LocNo) of inserted defs here.
+ void addDefsFromCopies(LiveInterval *LI, unsigned LocNo,
+ const SmallVectorImpl<SlotIndex> &Kills,
+ SmallVectorImpl<std::pair<SlotIndex, unsigned> > &NewDefs,
+ MachineRegisterInfo &MRI,
+ LiveIntervals &LIS);
+
/// computeIntervals - Compute the live intervals of all locations after
/// collecting all their def points.
- void computeIntervals(LiveIntervals &LIS, MachineDominatorTree &MDT);
+ void computeIntervals(MachineRegisterInfo &MRI,
+ LiveIntervals &LIS, MachineDominatorTree &MDT);
/// renameRegister - Update locations to rewrite OldReg as NewReg:SubIdx.
void renameRegister(unsigned OldReg, unsigned NewReg, unsigned SubIdx,
/// 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.
userVarMap.clear();
}
+ /// mapVirtReg - Map virtual register to an equivalence class.
+ void mapVirtReg(unsigned VirtReg, UserValue *EC);
+
/// renameRegister - Replace all references to OldReg wiht NewReg:SubIdx.
void renameRegister(unsigned OldReg, unsigned NewReg, unsigned SubIdx);
}
}
+void UserValue::mapVirtRegs(LDVImpl *LDV) {
+ for (unsigned i = 0, e = locations.size(); i != e; ++i)
+ if (locations[i].isReg() &&
+ TargetRegisterInfo::isVirtualRegister(locations[i].getReg()))
+ LDV->mapVirtReg(locations[i].getReg(), this);
+}
+
UserValue *LDVImpl::getUserValue(const MDNode *Var, unsigned Offset,
DebugLoc DL) {
UserValue *&Leader = userVarMap[Var];
unsigned Offset = MI->getOperand(1).getImm();
const MDNode *Var = MI->getOperand(2).getMetadata();
UserValue *UV = getUserValue(Var, Offset, MI->getDebugLoc());
-
- // If the location is a virtual register, make sure it is mapped.
- if (MI->getOperand(0).isReg()) {
- unsigned Reg = MI->getOperand(0).getReg();
- if (TargetRegisterInfo::isVirtualRegister(Reg))
- mapVirtReg(Reg, UV);
- }
-
UV->addDef(Idx, MI->getOperand(0));
return true;
}
void UserValue::extendDef(SlotIndex Idx, unsigned LocNo,
LiveInterval *LI, const VNInfo *VNI,
+ SmallVectorImpl<SlotIndex> *Kills,
LiveIntervals &LIS, MachineDominatorTree &MDT) {
SmallVector<SlotIndex, 16> Todo;
Todo.push_back(Idx);
bool ToEnd = true;
if (LI && VNI) {
LiveRange *Range = LI->getLiveRangeContaining(Start);
- if (!Range || Range->valno != VNI)
+ if (!Range || Range->valno != VNI) {
+ if (Kills)
+ Kills->push_back(Start);
continue;
+ }
if (Range->end < Stop)
Stop = Range->end, ToEnd = false;
}
// 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;
}
void
-UserValue::computeIntervals(LiveIntervals &LIS, MachineDominatorTree &MDT) {
+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();
+
+ // 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());
+ 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");
+ 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,
+ LiveIntervals &LIS,
+ MachineDominatorTree &MDT) {
SmallVector<std::pair<SlotIndex, unsigned>, 16> Defs;
// Collect all defs to be extended (Skipping undefs).
if (I.value() != ~0u)
Defs.push_back(std::make_pair(I.start(), I.value()));
- for (unsigned i = 0, e = Defs.size(); i != e; ++i) {
+ // 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() && LIS.hasInterval(Loc.getReg())) {
LiveInterval *LI = &LIS.getInterval(Loc.getReg());
const VNInfo *VNI = LI->getVNInfoAt(Idx);
- extendDef(Idx, LocNo, LI, VNI, LIS, MDT);
+ 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, LIS, MDT);
+ extendDef(Idx, LocNo, 0, 0, 0, LIS, MDT);
}
// Finally, erase all the undefs.
}
void LDVImpl::computeIntervals() {
- for (unsigned i = 0, e = userValues.size(); i != e; ++i)
- userValues[i]->computeIntervals(*LIS, *MDT);
+ for (unsigned i = 0, e = userValues.size(); i != e; ++i) {
+ userValues[i]->computeIntervals(MF->getRegInfo(), *LIS, *MDT);
+ userValues[i]->mapVirtRegs(this);
+ }
}
bool LDVImpl::runOnMachineFunction(MachineFunction &mf) {
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