SelectionDAGISel::SelectionDAGISel(const TargetMachine &tm, CodeGenOpt::Level OL) :
MachineFunctionPass(&ID), TM(tm), TLI(*tm.getTargetLowering()),
FuncInfo(new FunctionLoweringInfo(TLI)),
- CurDAG(new SelectionDAG(tm, *FuncInfo)),
+ CurDAG(new SelectionDAG(tm)),
SDB(new SelectionDAGBuilder(*CurDAG, *FuncInfo, OL)),
GFI(),
OptLevel(OL),
DEBUG(dbgs() << "\n\n\n=== " << Fn.getName() << "\n");
CurDAG->init(*MF);
- FuncInfo->set(Fn, *MF, EnableFastISel);
+ FuncInfo->set(Fn, *MF);
SDB->init(GFI, *AA);
SelectAllBasicBlocks(Fn);
};
}
-/// TrivialTruncElim - Eliminate some trivial nops that can result from
-/// ShrinkDemandedOps: (trunc (ext n)) -> n.
-static bool TrivialTruncElim(SDValue Op,
- TargetLowering::TargetLoweringOpt &TLO) {
- SDValue N0 = Op.getOperand(0);
- EVT VT = Op.getValueType();
- if ((N0.getOpcode() == ISD::ZERO_EXTEND ||
- N0.getOpcode() == ISD::SIGN_EXTEND ||
- N0.getOpcode() == ISD::ANY_EXTEND) &&
- N0.getOperand(0).getValueType() == VT) {
- return TLO.CombineTo(Op, N0.getOperand(0));
- }
- return false;
-}
-
-/// ShrinkDemandedOps - A late transformation pass that shrink expressions
-/// using TargetLowering::TargetLoweringOpt::ShrinkDemandedOp. It converts
-/// x+y to (VT)((SmallVT)x+(SmallVT)y) if the casts are free.
-void SelectionDAGISel::ShrinkDemandedOps() {
- SmallVector<SDNode*, 128> Worklist;
- SmallPtrSet<SDNode*, 128> InWorklist;
-
- // Add all the dag nodes to the worklist.
- Worklist.reserve(CurDAG->allnodes_size());
- for (SelectionDAG::allnodes_iterator I = CurDAG->allnodes_begin(),
- E = CurDAG->allnodes_end(); I != E; ++I) {
- Worklist.push_back(I);
- InWorklist.insert(I);
- }
-
- TargetLowering::TargetLoweringOpt TLO(*CurDAG, true, true, true);
- while (!Worklist.empty()) {
- SDNode *N = Worklist.pop_back_val();
- InWorklist.erase(N);
-
- if (N->use_empty() && N != CurDAG->getRoot().getNode()) {
- // Deleting this node may make its operands dead, add them to the worklist
- // if they aren't already there.
- for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i)
- if (InWorklist.insert(N->getOperand(i).getNode()))
- Worklist.push_back(N->getOperand(i).getNode());
-
- CurDAG->DeleteNode(N);
- continue;
- }
-
- // Run ShrinkDemandedOp on scalar binary operations.
- if (N->getNumValues() != 1 ||
- !N->getValueType(0).isSimple() || !N->getValueType(0).isInteger())
- continue;
-
- unsigned BitWidth = N->getValueType(0).getScalarType().getSizeInBits();
- APInt Demanded = APInt::getAllOnesValue(BitWidth);
- APInt KnownZero, KnownOne;
- if (!TLI.SimplifyDemandedBits(SDValue(N, 0), Demanded,
- KnownZero, KnownOne, TLO) &&
- (N->getOpcode() != ISD::TRUNCATE ||
- !TrivialTruncElim(SDValue(N, 0), TLO)))
- continue;
-
- // Revisit the node.
- assert(!InWorklist.count(N) && "Already in worklist");
- Worklist.push_back(N);
- InWorklist.insert(N);
-
- // Replace the old value with the new one.
- DEBUG(errs() << "\nShrinkDemandedOps replacing ";
- TLO.Old.getNode()->dump(CurDAG);
- errs() << "\nWith: ";
- TLO.New.getNode()->dump(CurDAG);
- errs() << '\n');
-
- if (InWorklist.insert(TLO.New.getNode()))
- Worklist.push_back(TLO.New.getNode());
-
- SDOPsWorkListRemover DeadNodes(Worklist, InWorklist);
- CurDAG->ReplaceAllUsesOfValueWith(TLO.Old, TLO.New, &DeadNodes);
-
- if (!TLO.Old.getNode()->use_empty()) continue;
-
- for (unsigned i = 0, e = TLO.Old.getNode()->getNumOperands();
- i != e; ++i) {
- SDNode *OpNode = TLO.Old.getNode()->getOperand(i).getNode();
- if (OpNode->hasOneUse()) {
- // Add OpNode to the end of the list to revisit.
- DeadNodes.RemoveFromWorklist(OpNode);
- Worklist.push_back(OpNode);
- InWorklist.insert(OpNode);
- }
- }
-
- DeadNodes.RemoveFromWorklist(TLO.Old.getNode());
- CurDAG->DeleteNode(TLO.Old.getNode());
- }
-}
-
void SelectionDAGISel::ComputeLiveOutVRegInfo() {
SmallPtrSet<SDNode*, 128> VisitedNodes;
SmallVector<SDNode*, 128> Worklist;
BlockName = MF->getFunction()->getNameStr() + ":" +
BB->getBasicBlock()->getNameStr();
- DEBUG(dbgs() << "Initial selection DAG:\n");
- DEBUG(CurDAG->dump());
+ DEBUG(dbgs() << "Initial selection DAG:\n"; CurDAG->dump());
if (ViewDAGCombine1) CurDAG->viewGraph("dag-combine1 input for " + BlockName);
// Run the DAG combiner in pre-legalize mode.
- if (TimePassesIsEnabled) {
- NamedRegionTimer T("DAG Combining 1", GroupName);
- CurDAG->Combine(Unrestricted, *AA, OptLevel);
- } else {
+ {
+ NamedRegionTimer T("DAG Combining 1", GroupName, TimePassesIsEnabled);
CurDAG->Combine(Unrestricted, *AA, OptLevel);
}
- DEBUG(dbgs() << "Optimized lowered selection DAG:\n");
- DEBUG(CurDAG->dump());
+ DEBUG(dbgs() << "Optimized lowered selection DAG:\n"; CurDAG->dump());
// Second step, hack on the DAG until it only uses operations and types that
// the target supports.
BlockName);
bool Changed;
- if (TimePassesIsEnabled) {
- NamedRegionTimer T("Type Legalization", GroupName);
- Changed = CurDAG->LegalizeTypes();
- } else {
+ {
+ NamedRegionTimer T("Type Legalization", GroupName, TimePassesIsEnabled);
Changed = CurDAG->LegalizeTypes();
}
- DEBUG(dbgs() << "Type-legalized selection DAG:\n");
- DEBUG(CurDAG->dump());
+ DEBUG(dbgs() << "Type-legalized selection DAG:\n"; CurDAG->dump());
if (Changed) {
if (ViewDAGCombineLT)
CurDAG->viewGraph("dag-combine-lt input for " + BlockName);
// Run the DAG combiner in post-type-legalize mode.
- if (TimePassesIsEnabled) {
- NamedRegionTimer T("DAG Combining after legalize types", GroupName);
- CurDAG->Combine(NoIllegalTypes, *AA, OptLevel);
- } else {
+ {
+ NamedRegionTimer T("DAG Combining after legalize types", GroupName,
+ TimePassesIsEnabled);
CurDAG->Combine(NoIllegalTypes, *AA, OptLevel);
}
- DEBUG(dbgs() << "Optimized type-legalized selection DAG:\n");
- DEBUG(CurDAG->dump());
+ DEBUG(dbgs() << "Optimized type-legalized selection DAG:\n";
+ CurDAG->dump());
}
- if (TimePassesIsEnabled) {
- NamedRegionTimer T("Vector Legalization", GroupName);
- Changed = CurDAG->LegalizeVectors();
- } else {
+ {
+ NamedRegionTimer T("Vector Legalization", GroupName, TimePassesIsEnabled);
Changed = CurDAG->LegalizeVectors();
}
if (Changed) {
- if (TimePassesIsEnabled) {
- NamedRegionTimer T("Type Legalization 2", GroupName);
- CurDAG->LegalizeTypes();
- } else {
+ {
+ NamedRegionTimer T("Type Legalization 2", GroupName, TimePassesIsEnabled);
CurDAG->LegalizeTypes();
}
CurDAG->viewGraph("dag-combine-lv input for " + BlockName);
// Run the DAG combiner in post-type-legalize mode.
- if (TimePassesIsEnabled) {
- NamedRegionTimer T("DAG Combining after legalize vectors", GroupName);
- CurDAG->Combine(NoIllegalOperations, *AA, OptLevel);
- } else {
+ {
+ NamedRegionTimer T("DAG Combining after legalize vectors", GroupName,
+ TimePassesIsEnabled);
CurDAG->Combine(NoIllegalOperations, *AA, OptLevel);
}
- DEBUG(dbgs() << "Optimized vector-legalized selection DAG:\n");
- DEBUG(CurDAG->dump());
+ DEBUG(dbgs() << "Optimized vector-legalized selection DAG:\n";
+ CurDAG->dump());
}
if (ViewLegalizeDAGs) CurDAG->viewGraph("legalize input for " + BlockName);
- if (TimePassesIsEnabled) {
- NamedRegionTimer T("DAG Legalization", GroupName);
- CurDAG->Legalize(OptLevel);
- } else {
+ {
+ NamedRegionTimer T("DAG Legalization", GroupName, TimePassesIsEnabled);
CurDAG->Legalize(OptLevel);
}
- DEBUG(dbgs() << "Legalized selection DAG:\n");
- DEBUG(CurDAG->dump());
+ DEBUG(dbgs() << "Legalized selection DAG:\n"; CurDAG->dump());
if (ViewDAGCombine2) CurDAG->viewGraph("dag-combine2 input for " + BlockName);
// Run the DAG combiner in post-legalize mode.
- if (TimePassesIsEnabled) {
- NamedRegionTimer T("DAG Combining 2", GroupName);
- CurDAG->Combine(NoIllegalOperations, *AA, OptLevel);
- } else {
+ {
+ NamedRegionTimer T("DAG Combining 2", GroupName, TimePassesIsEnabled);
CurDAG->Combine(NoIllegalOperations, *AA, OptLevel);
}
- DEBUG(dbgs() << "Optimized legalized selection DAG:\n");
- DEBUG(CurDAG->dump());
+ DEBUG(dbgs() << "Optimized legalized selection DAG:\n"; CurDAG->dump());
- if (OptLevel != CodeGenOpt::None) {
- ShrinkDemandedOps();
+ if (OptLevel != CodeGenOpt::None)
ComputeLiveOutVRegInfo();
- }
if (ViewISelDAGs) CurDAG->viewGraph("isel input for " + BlockName);
// Third, instruction select all of the operations to machine code, adding the
// code to the MachineBasicBlock.
- if (TimePassesIsEnabled) {
- NamedRegionTimer T("Instruction Selection", GroupName);
- DoInstructionSelection();
- } else {
+ {
+ NamedRegionTimer T("Instruction Selection", GroupName, TimePassesIsEnabled);
DoInstructionSelection();
}
- DEBUG(dbgs() << "Selected selection DAG:\n");
- DEBUG(CurDAG->dump());
+ DEBUG(dbgs() << "Selected selection DAG:\n"; CurDAG->dump());
if (ViewSchedDAGs) CurDAG->viewGraph("scheduler input for " + BlockName);
// Schedule machine code.
ScheduleDAGSDNodes *Scheduler = CreateScheduler();
- if (TimePassesIsEnabled) {
- NamedRegionTimer T("Instruction Scheduling", GroupName);
- Scheduler->Run(CurDAG, BB, BB->end());
- } else {
+ {
+ NamedRegionTimer T("Instruction Scheduling", GroupName,
+ TimePassesIsEnabled);
Scheduler->Run(CurDAG, BB, BB->end());
}
// Emit machine code to BB. This can change 'BB' to the last block being
// inserted into.
- if (TimePassesIsEnabled) {
- NamedRegionTimer T("Instruction Creation", GroupName);
- BB = Scheduler->EmitSchedule();
- } else {
+ {
+ NamedRegionTimer T("Instruction Creation", GroupName, TimePassesIsEnabled);
BB = Scheduler->EmitSchedule();
}
// Free the scheduler state.
- if (TimePassesIsEnabled) {
- NamedRegionTimer T("Instruction Scheduling Cleanup", GroupName);
- delete Scheduler;
- } else {
+ {
+ NamedRegionTimer T("Instruction Scheduling Cleanup", GroupName,
+ TimePassesIsEnabled);
delete Scheduler;
}
FastIS->startNewBlock(BB);
// Do FastISel on as many instructions as possible.
for (; BI != End; ++BI) {
+ // Defer instructions with no side effects; they'll be emitted
+ // on-demand later.
+ if (BI->isSafeToSpeculativelyExecute() &&
+ !FuncInfo->isExportedInst(BI))
+ continue;
+
// Try to select the instruction with FastISel.
if (FastIS->SelectInstruction(BI))
continue;
if (!BI->getType()->isVoidTy() && !BI->use_empty()) {
unsigned &R = FuncInfo->ValueMap[BI];
if (!R)
- R = FuncInfo->CreateRegForValue(BI);
+ R = FuncInfo->CreateReg(BI->getType());
}
bool HadTailCall = false;
SelectionDAGISel::FinishBasicBlock(MachineBasicBlock *BB) {
DEBUG(dbgs() << "Total amount of phi nodes to update: "
- << FuncInfo->PHINodesToUpdate.size() << "\n");
- DEBUG(for (unsigned i = 0, e = FuncInfo->PHINodesToUpdate.size(); i != e; ++i)
+ << FuncInfo->PHINodesToUpdate.size() << "\n";
+ for (unsigned i = 0, e = FuncInfo->PHINodesToUpdate.size(); i != e; ++i)
dbgs() << "Node " << i << " : ("
<< FuncInfo->PHINodesToUpdate[i].first
<< ", " << FuncInfo->PHINodesToUpdate[i].second << ")\n");