using namespace llvm;
-void LiveRangeCalc::reset(const MachineFunction *MF,
+void LiveRangeCalc::reset(const MachineFunction *mf,
SlotIndexes *SI,
MachineDominatorTree *MDT,
VNInfo::Allocator *VNIA) {
+ MF = mf;
MRI = &MF->getRegInfo();
Indexes = SI;
DomTree = MDT;
.getRegSlot(I.getOperand().isEarlyClobber());
// Create the def in LI. This may find an existing def.
- VNInfo *VNI = LI->createDeadDef(Idx, *Alloc);
- VNI->setIsPHIDef(MI->isPHI());
+ LI->createDeadDef(Idx, *Alloc);
}
}
// Visit all operands that read Reg. This may include partial defs.
for (MachineRegisterInfo::reg_nodbg_iterator I = MRI->reg_nodbg_begin(Reg),
E = MRI->reg_nodbg_end(); I != E; ++I) {
- const MachineOperand &MO = I.getOperand();
+ MachineOperand &MO = I.getOperand();
+ // Clear all kill flags. They will be reinserted after register allocation
+ // by LiveIntervalAnalysis::addKillFlags().
+ if (MO.isUse())
+ MO.setIsKill(false);
if (!MO.readsReg())
continue;
// MI is reading Reg. We may have visited MI before if it happens to be
Idx = Idx.getRegSlot(true);
}
}
- extend(LI, Idx);
+ extend(LI, Idx, Reg);
}
}
// Transfer information from the LiveIn vector to the live ranges.
-void LiveRangeCalc::updateLiveIns(VNInfo *OverrideVNI) {
+void LiveRangeCalc::updateLiveIns() {
+ LiveRangeUpdater Updater;
for (SmallVectorImpl<LiveInBlock>::iterator I = LiveIn.begin(),
E = LiveIn.end(); I != E; ++I) {
if (!I->DomNode)
continue;
MachineBasicBlock *MBB = I->DomNode->getBlock();
-
- VNInfo *VNI = OverrideVNI ? OverrideVNI : I->Value;
- assert(VNI && "No live-in value found");
-
+ assert(I->Value && "No live-in value found");
SlotIndex Start, End;
tie(Start, End) = Indexes->getMBBRange(MBB);
if (I->Kill.isValid())
- I->LI->addRange(LiveRange(Start, I->Kill, VNI));
+ // Value is killed inside this block.
+ End = I->Kill;
else {
- I->LI->addRange(LiveRange(Start, End, VNI));
- // The value is live-through, update LiveOut as well. Defer the Domtree
- // lookup until it is needed.
+ // The value is live-through, update LiveOut as well.
+ // Defer the Domtree lookup until it is needed.
assert(Seen.test(MBB->getNumber()));
- LiveOut[MBB] = LiveOutPair(VNI, (MachineDomTreeNode *)0);
+ LiveOut[MBB] = LiveOutPair(I->Value, (MachineDomTreeNode *)0);
}
+ Updater.setDest(I->LI);
+ Updater.add(Start, End, I->Value);
}
LiveIn.clear();
}
void LiveRangeCalc::extend(LiveInterval *LI,
- SlotIndex Kill) {
+ SlotIndex Kill,
+ unsigned PhysReg) {
assert(LI && "Missing live range");
assert(Kill.isValid() && "Invalid SlotIndex");
assert(Indexes && "Missing SlotIndexes");
// multiple values, and we may need to create even more phi-defs to preserve
// VNInfo SSA form. Perform a search for all predecessor blocks where we
// know the dominating VNInfo.
- VNInfo *VNI = findReachingDefs(LI, KillMBB, Kill);
+ if (findReachingDefs(LI, KillMBB, Kill, PhysReg))
+ return;
// When there were multiple different values, we may need new PHIs.
- if (!VNI)
- updateSSA();
-
- updateLiveIns(VNI);
+ calculateValues();
}
assert(Indexes && "Missing SlotIndexes");
assert(DomTree && "Missing dominator tree");
updateSSA();
- updateLiveIns(0);
+ updateLiveIns();
}
-VNInfo *LiveRangeCalc::findReachingDefs(LiveInterval *LI,
- MachineBasicBlock *KillMBB,
- SlotIndex Kill) {
- // Blocks where LI should be live-in.
- SmallVector<MachineBasicBlock*, 16> WorkList(1, KillMBB);
+bool LiveRangeCalc::findReachingDefs(LiveInterval *LI,
+ MachineBasicBlock *KillMBB,
+ SlotIndex Kill,
+ unsigned PhysReg) {
+ unsigned KillMBBNum = KillMBB->getNumber();
+
+ // Block numbers where LI should be live-in.
+ SmallVector<unsigned, 16> WorkList(1, KillMBBNum);
// Remember if we have seen more than one value.
bool UniqueVNI = true;
// Using Seen as a visited set, perform a BFS for all reaching defs.
for (unsigned i = 0; i != WorkList.size(); ++i) {
- MachineBasicBlock *MBB = WorkList[i];
- assert(!MBB->pred_empty() && "Value live-in to entry block?");
+ MachineBasicBlock *MBB = MF->getBlockNumbered(WorkList[i]);
+
+#ifndef NDEBUG
+ if (MBB->pred_empty()) {
+ MBB->getParent()->verify();
+ llvm_unreachable("Use not jointly dominated by defs.");
+ }
+
+ if (TargetRegisterInfo::isPhysicalRegister(PhysReg) &&
+ !MBB->isLiveIn(PhysReg)) {
+ MBB->getParent()->verify();
+ errs() << "The register needs to be live in to BB#" << MBB->getNumber()
+ << ", but is missing from the live-in list.\n";
+ llvm_unreachable("Invalid global physical register");
+ }
+#endif
+
for (MachineBasicBlock::pred_iterator PI = MBB->pred_begin(),
PE = MBB->pred_end(); PI != PE; ++PI) {
MachineBasicBlock *Pred = *PI;
// No, we need a live-in value for Pred as well
if (Pred != KillMBB)
- WorkList.push_back(Pred);
+ WorkList.push_back(Pred->getNumber());
else
// Loopback to KillMBB, so value is really live through.
Kill = SlotIndex();
}
}
- // Transfer WorkList to LiveInBlocks in reverse order.
- // This ordering works best with updateSSA().
LiveIn.clear();
- LiveIn.reserve(WorkList.size());
- while(!WorkList.empty())
- addLiveInBlock(LI, DomTree->getNode(WorkList.pop_back_val()));
- // The kill block may not be live-through.
- assert(LiveIn.back().DomNode->getBlock() == KillMBB);
- LiveIn.back().Kill = Kill;
+ // Both updateSSA() and LiveRangeUpdater benefit from ordered blocks, but
+ // neither require it. Skip the sorting overhead for small updates.
+ if (WorkList.size() > 4)
+ array_pod_sort(WorkList.begin(), WorkList.end());
+
+ // If a unique reaching def was found, blit in the live ranges immediately.
+ if (UniqueVNI) {
+ LiveRangeUpdater Updater(LI);
+ for (SmallVectorImpl<unsigned>::const_iterator
+ I = WorkList.begin(), E = WorkList.end(); I != E; ++I) {
+ SlotIndex Start, End;
+ tie(Start, End) = Indexes->getMBBRange(*I);
+ // Trim the live range in KillMBB.
+ if (*I == KillMBBNum && Kill.isValid())
+ End = Kill;
+ else
+ LiveOut[MF->getBlockNumbered(*I)] =
+ LiveOutPair(TheVNI, (MachineDomTreeNode *)0);
+ Updater.add(Start, End, TheVNI);
+ }
+ return true;
+ }
+
+ // Multiple values were found, so transfer the work list to the LiveIn array
+ // where UpdateSSA will use it as a work list.
+ LiveIn.reserve(WorkList.size());
+ for (SmallVectorImpl<unsigned>::const_iterator
+ I = WorkList.begin(), E = WorkList.end(); I != E; ++I) {
+ MachineBasicBlock *MBB = MF->getBlockNumbered(*I);
+ addLiveInBlock(LI, DomTree->getNode(MBB));
+ if (MBB == KillMBB)
+ LiveIn.back().Kill = Kill;
+ }
- return UniqueVNI ? TheVNI : 0;
+ return false;
}
SlotIndex Start, End;
tie(Start, End) = Indexes->getMBBRange(MBB);
VNInfo *VNI = I->LI->getNextValue(Start, *Alloc);
- VNI->setIsPHIDef(true);
I->Value = VNI;
// This block is done, we know the final value.
I->DomNode = 0;
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