[llvm-commits] [llvm] r166122 - in /llvm/trunk: include/llvm/CodeGen/SchedulerRegistry.h lib/CodeGen/SelectionDAG/ScheduleDAGFast.cpp lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.cpp lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.h
Jim Grosbach
grosbach at apple.com
Wed Oct 17 14:52:48 PDT 2012
Any reasonable way to get some test cases?
-Jim
On Oct 17, 2012, at 12:39 PM, Evan Cheng <evan.cheng at apple.com> wrote:
> Author: evancheng
> Date: Wed Oct 17 14:39:36 2012
> New Revision: 166122
>
> URL: http://llvm.org/viewvc/llvm-project?rev=166122&view=rev
> Log:
> Add a really faster pre-RA scheduler (-pre-RA-sched=linearize). It doesn't use
> any scheduling heuristics nor does it build up any scheduling data structure
> that other heuristics use. It essentially linearize by doing a DFA walk but
> it does handle glues correctly.
>
> IMPORTANT: it probably can't handle all the physical register dependencies so
> it's not suitable for x86. It also doesn't deal with dbg_value nodes right now
> so it's definitely is still WIP.
>
> rdar://12474515
>
> Modified:
> llvm/trunk/include/llvm/CodeGen/SchedulerRegistry.h
> llvm/trunk/lib/CodeGen/SelectionDAG/ScheduleDAGFast.cpp
> llvm/trunk/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.cpp
> llvm/trunk/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.h
>
> Modified: llvm/trunk/include/llvm/CodeGen/SchedulerRegistry.h
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/CodeGen/SchedulerRegistry.h?rev=166122&r1=166121&r2=166122&view=diff
> ==============================================================================
> --- llvm/trunk/include/llvm/CodeGen/SchedulerRegistry.h (original)
> +++ llvm/trunk/include/llvm/CodeGen/SchedulerRegistry.h Wed Oct 17 14:39:36 2012
> @@ -102,6 +102,11 @@
> ScheduleDAGSDNodes *createDefaultScheduler(SelectionDAGISel *IS,
> CodeGenOpt::Level OptLevel);
>
> +/// createDAGLinearizer - This creates a "no-scheduling" scheduler which
> +/// linearize the DAG using topological order.
> +ScheduleDAGSDNodes *createDAGLinearizer(SelectionDAGISel *IS,
> + CodeGenOpt::Level OptLevel);
> +
> } // end namespace llvm
>
> #endif
>
> Modified: llvm/trunk/lib/CodeGen/SelectionDAG/ScheduleDAGFast.cpp
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/ScheduleDAGFast.cpp?rev=166122&r1=166121&r2=166122&view=diff
> ==============================================================================
> --- llvm/trunk/lib/CodeGen/SelectionDAG/ScheduleDAGFast.cpp (original)
> +++ llvm/trunk/lib/CodeGen/SelectionDAG/ScheduleDAGFast.cpp Wed Oct 17 14:39:36 2012
> @@ -13,6 +13,7 @@
>
> #define DEBUG_TYPE "pre-RA-sched"
> #include "ScheduleDAGSDNodes.h"
> +#include "InstrEmitter.h"
> #include "llvm/InlineAsm.h"
> #include "llvm/CodeGen/SchedulerRegistry.h"
> #include "llvm/CodeGen/SelectionDAGISel.h"
> @@ -34,6 +35,10 @@
> static RegisterScheduler
> fastDAGScheduler("fast", "Fast suboptimal list scheduling",
> createFastDAGScheduler);
> +static RegisterScheduler
> + linearizeDAGScheduler("linearize", "Linearize DAG, no scheduling",
> + createDAGLinearizer);
> +
>
> namespace {
> /// FastPriorityQueue - A degenerate priority queue that considers
> @@ -629,6 +634,153 @@
> #endif
> }
>
> +
> +//===----------------------------------------------------------------------===//
> +// ScheduleDAGLinearize - No scheduling scheduler, it simply linearize the
> +// DAG in topological order.
> +// IMPORTANT: this may not work for targets with phyreg dependency.
> +//
> +class ScheduleDAGLinearize : public ScheduleDAGSDNodes {
> +public:
> + ScheduleDAGLinearize(MachineFunction &mf) : ScheduleDAGSDNodes(mf) {}
> +
> + void Schedule();
> +
> + MachineBasicBlock *EmitSchedule(MachineBasicBlock::iterator &InsertPos);
> +
> +private:
> + std::vector<SDNode*> Sequence;
> + DenseMap<SDNode*, SDNode*> GluedMap; // Cache glue to its user
> +
> + void ScheduleNode(SDNode *N);
> +};
> +
> +void ScheduleDAGLinearize::ScheduleNode(SDNode *N) {
> + if (N->getNodeId() != 0)
> + llvm_unreachable(0);
> +
> + if (!N->isMachineOpcode() &&
> + (N->getOpcode() == ISD::EntryToken || isPassiveNode(N)))
> + // These nodes do not need to be translated into MIs.
> + return;
> +
> + DEBUG(dbgs() << "\n*** Scheduling: ");
> + DEBUG(N->dump(DAG));
> + Sequence.push_back(N);
> +
> + unsigned NumOps = N->getNumOperands();
> + if (unsigned NumLeft = NumOps) {
> + SDNode *GluedOpN = 0;
> + do {
> + const SDValue &Op = N->getOperand(NumLeft-1);
> + SDNode *OpN = Op.getNode();
> +
> + if (NumLeft == NumOps && Op.getValueType() == MVT::Glue) {
> + // Schedule glue operand right above N.
> + GluedOpN = OpN;
> + assert(OpN->getNodeId() != 0 && "Glue operand not ready?");
> + OpN->setNodeId(0);
> + ScheduleNode(OpN);
> + continue;
> + }
> +
> + if (OpN == GluedOpN)
> + // Glue operand is already scheduled.
> + continue;
> +
> + DenseMap<SDNode*, SDNode*>::iterator DI = GluedMap.find(OpN);
> + if (DI != GluedMap.end() && DI->second != N)
> + // Users of glues are counted against the glued users.
> + OpN = DI->second;
> +
> + unsigned Degree = OpN->getNodeId();
> + assert(Degree > 0 && "Predecessor over-released!");
> + OpN->setNodeId(--Degree);
> + if (Degree == 0)
> + ScheduleNode(OpN);
> + } while (--NumLeft);
> + }
> +}
> +
> +/// findGluedUser - Find the representative use of a glue value by walking
> +/// the use chain.
> +static SDNode *findGluedUser(SDNode *N) {
> + while (SDNode *Glued = N->getGluedUser())
> + N = Glued;
> + return N;
> +}
> +
> +void ScheduleDAGLinearize::Schedule() {
> + DEBUG(dbgs() << "********** DAG Linearization **********\n");
> +
> + SmallVector<SDNode*, 8> Glues;
> + unsigned DAGSize = 0;
> + for (SelectionDAG::allnodes_iterator I = DAG->allnodes_begin(),
> + E = DAG->allnodes_end(); I != E; ++I) {
> + SDNode *N = I;
> +
> + // Use node id to record degree.
> + unsigned Degree = N->use_size();
> + N->setNodeId(Degree);
> + unsigned NumVals = N->getNumValues();
> + if (NumVals && N->getValueType(NumVals-1) == MVT::Glue &&
> + N->hasAnyUseOfValue(NumVals-1)) {
> + SDNode *User = findGluedUser(N);
> + if (User) {
> + Glues.push_back(N);
> + GluedMap.insert(std::make_pair(N, User));
> + }
> + }
> +
> + if (N->isMachineOpcode() ||
> + (N->getOpcode() != ISD::EntryToken && !isPassiveNode(N)))
> + ++DAGSize;
> + }
> +
> + for (unsigned i = 0, e = Glues.size(); i != e; ++i) {
> + SDNode *Glue = Glues[i];
> + SDNode *GUser = GluedMap[Glue];
> + unsigned Degree = Glue->getNodeId();
> + unsigned UDegree = GUser->getNodeId();
> +
> + // Glue user must be scheduled together with the glue operand. So other
> + // users of the glue operand must be treated as its users.
> + SDNode *ImmGUser = Glue->getGluedUser();
> + for (SDNode::use_iterator ui = Glue->use_begin(), ue = Glue->use_end();
> + ui != ue; ++ui)
> + if (*ui == ImmGUser)
> + --Degree;
> + GUser->setNodeId(UDegree + Degree);
> + Glue->setNodeId(1);
> + }
> +
> + Sequence.reserve(DAGSize);
> + ScheduleNode(DAG->getRoot().getNode());
> +}
> +
> +MachineBasicBlock*
> +ScheduleDAGLinearize::EmitSchedule(MachineBasicBlock::iterator &InsertPos) {
> + InstrEmitter Emitter(BB, InsertPos);
> + DenseMap<SDValue, unsigned> VRBaseMap;
> +
> + DEBUG({
> + dbgs() << "\n*** Final schedule ***\n";
> + });
> +
> + // FIXME: Handle dbg_values.
> + unsigned NumNodes = Sequence.size();
> + for (unsigned i = 0; i != NumNodes; ++i) {
> + SDNode *N = Sequence[NumNodes-i-1];
> + DEBUG(N->dump(DAG));
> + Emitter.EmitNode(N, false, false, VRBaseMap);
> + }
> +
> + DEBUG(dbgs() << '\n');
> +
> + InsertPos = Emitter.getInsertPos();
> + return Emitter.getBlock();
> +}
> +
> //===----------------------------------------------------------------------===//
> // Public Constructor Functions
> //===----------------------------------------------------------------------===//
> @@ -637,3 +789,8 @@
> llvm::createFastDAGScheduler(SelectionDAGISel *IS, CodeGenOpt::Level) {
> return new ScheduleDAGFast(*IS->MF);
> }
> +
> +llvm::ScheduleDAGSDNodes *
> +llvm::createDAGLinearizer(SelectionDAGISel *IS, CodeGenOpt::Level) {
> + return new ScheduleDAGLinearize(*IS->MF);
> +}
>
> Modified: llvm/trunk/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.cpp
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.cpp?rev=166122&r1=166121&r2=166122&view=diff
> ==============================================================================
> --- llvm/trunk/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.cpp (original)
> +++ llvm/trunk/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.cpp Wed Oct 17 14:39:36 2012
> @@ -831,8 +831,7 @@
> }
>
> SmallVector<SDNode *, 4> GluedNodes;
> - for (SDNode *N = SU->getNode()->getGluedNode(); N;
> - N = N->getGluedNode())
> + for (SDNode *N = SU->getNode()->getGluedNode(); N; N = N->getGluedNode())
> GluedNodes.push_back(N);
> while (!GluedNodes.empty()) {
> SDNode *N = GluedNodes.back();
>
> Modified: llvm/trunk/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.h
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.h?rev=166122&r1=166121&r2=166122&view=diff
> ==============================================================================
> --- llvm/trunk/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.h (original)
> +++ llvm/trunk/lib/CodeGen/SelectionDAG/ScheduleDAGSDNodes.h Wed Oct 17 14:39:36 2012
> @@ -114,7 +114,8 @@
> /// EmitSchedule - Insert MachineInstrs into the MachineBasicBlock
> /// according to the order specified in Sequence.
> ///
> - MachineBasicBlock *EmitSchedule(MachineBasicBlock::iterator &InsertPos);
> + virtual MachineBasicBlock*
> + EmitSchedule(MachineBasicBlock::iterator &InsertPos);
>
> virtual void dumpNode(const SUnit *SU) const;
>
>
>
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