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[PBQP] Move register-allocation specific PBQP code into RegAllocPBQP.h.
Just clean-up - no functional change. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220145 91177308-0d34-0410-b5e6-96231b3b80d8
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Lang Hames
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@ -1,409 +0,0 @@
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//===-- RegAllocSolver.h - Heuristic PBQP Solver for reg alloc --*- C++ -*-===//
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//
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// The LLVM Compiler Infrastructure
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//
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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//
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// Heuristic PBQP solver for register allocation problems. This solver uses a
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// graph reduction approach. Nodes of degree 0, 1 and 2 are eliminated with
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// optimality-preserving rules (see ReductionRules.h). When no low-degree (<3)
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// nodes are present, a heuristic derived from Brigg's graph coloring approach
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// is used.
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//
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//===----------------------------------------------------------------------===//
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#ifndef LLVM_CODEGEN_PBQP_REGALLOCSOLVER_H
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#define LLVM_CODEGEN_PBQP_REGALLOCSOLVER_H
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#include "CostAllocator.h"
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#include "Graph.h"
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#include "ReductionRules.h"
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#include "Solution.h"
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#include "llvm/Support/ErrorHandling.h"
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#include <limits>
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#include <vector>
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namespace llvm{
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namespace PBQP {
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namespace RegAlloc {
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/// @brief Spill option index.
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inline unsigned getSpillOptionIdx() { return 0; }
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/// \brief Metadata to speed allocatability test.
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///
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/// Keeps track of the number of infinities in each row and column.
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class MatrixMetadata {
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private:
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MatrixMetadata(const MatrixMetadata&);
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void operator=(const MatrixMetadata&);
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public:
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MatrixMetadata(const PBQP::Matrix& M)
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: WorstRow(0), WorstCol(0),
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UnsafeRows(new bool[M.getRows() - 1]()),
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UnsafeCols(new bool[M.getCols() - 1]()) {
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unsigned* ColCounts = new unsigned[M.getCols() - 1]();
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for (unsigned i = 1; i < M.getRows(); ++i) {
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unsigned RowCount = 0;
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for (unsigned j = 1; j < M.getCols(); ++j) {
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if (M[i][j] == std::numeric_limits<PBQP::PBQPNum>::infinity()) {
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++RowCount;
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++ColCounts[j - 1];
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UnsafeRows[i - 1] = true;
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UnsafeCols[j - 1] = true;
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}
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}
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WorstRow = std::max(WorstRow, RowCount);
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}
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unsigned WorstColCountForCurRow =
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*std::max_element(ColCounts, ColCounts + M.getCols() - 1);
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WorstCol = std::max(WorstCol, WorstColCountForCurRow);
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delete[] ColCounts;
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}
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~MatrixMetadata() {
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delete[] UnsafeRows;
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delete[] UnsafeCols;
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}
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unsigned getWorstRow() const { return WorstRow; }
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unsigned getWorstCol() const { return WorstCol; }
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const bool* getUnsafeRows() const { return UnsafeRows; }
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const bool* getUnsafeCols() const { return UnsafeCols; }
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private:
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unsigned WorstRow, WorstCol;
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bool* UnsafeRows;
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bool* UnsafeCols;
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};
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class NodeMetadata {
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public:
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typedef std::vector<unsigned> OptionToRegMap;
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typedef enum { Unprocessed,
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OptimallyReducible,
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ConservativelyAllocatable,
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NotProvablyAllocatable } ReductionState;
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NodeMetadata() : RS(Unprocessed), DeniedOpts(0), OptUnsafeEdges(nullptr){}
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~NodeMetadata() { delete[] OptUnsafeEdges; }
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void setVReg(unsigned VReg) { this->VReg = VReg; }
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unsigned getVReg() const { return VReg; }
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void setOptionRegs(OptionToRegMap OptionRegs) {
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this->OptionRegs = std::move(OptionRegs);
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}
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const OptionToRegMap& getOptionRegs() const { return OptionRegs; }
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void setup(const Vector& Costs) {
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NumOpts = Costs.getLength() - 1;
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OptUnsafeEdges = new unsigned[NumOpts]();
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}
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ReductionState getReductionState() const { return RS; }
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void setReductionState(ReductionState RS) { this->RS = RS; }
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void handleAddEdge(const MatrixMetadata& MD, bool Transpose) {
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DeniedOpts += Transpose ? MD.getWorstCol() : MD.getWorstRow();
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const bool* UnsafeOpts =
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Transpose ? MD.getUnsafeCols() : MD.getUnsafeRows();
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for (unsigned i = 0; i < NumOpts; ++i)
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OptUnsafeEdges[i] += UnsafeOpts[i];
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}
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void handleRemoveEdge(const MatrixMetadata& MD, bool Transpose) {
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DeniedOpts -= Transpose ? MD.getWorstCol() : MD.getWorstRow();
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const bool* UnsafeOpts =
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Transpose ? MD.getUnsafeCols() : MD.getUnsafeRows();
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for (unsigned i = 0; i < NumOpts; ++i)
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OptUnsafeEdges[i] -= UnsafeOpts[i];
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}
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bool isConservativelyAllocatable() const {
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return (DeniedOpts < NumOpts) ||
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(std::find(OptUnsafeEdges, OptUnsafeEdges + NumOpts, 0) !=
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OptUnsafeEdges + NumOpts);
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}
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private:
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ReductionState RS;
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unsigned NumOpts;
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unsigned DeniedOpts;
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unsigned* OptUnsafeEdges;
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unsigned VReg;
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OptionToRegMap OptionRegs;
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};
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class RegAllocSolverImpl {
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private:
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typedef PBQP::MDMatrix<MatrixMetadata> RAMatrix;
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public:
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typedef PBQP::Vector RawVector;
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typedef PBQP::Matrix RawMatrix;
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typedef PBQP::Vector Vector;
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typedef RAMatrix Matrix;
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typedef PBQP::PoolCostAllocator<
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Vector, PBQP::VectorComparator,
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Matrix, PBQP::MatrixComparator> CostAllocator;
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typedef PBQP::GraphBase::NodeId NodeId;
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typedef PBQP::GraphBase::EdgeId EdgeId;
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typedef RegAlloc::NodeMetadata NodeMetadata;
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struct EdgeMetadata { };
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class GraphMetadata {
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public:
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GraphMetadata(MachineFunction &MF,
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LiveIntervals &LIS,
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MachineBlockFrequencyInfo &MBFI)
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: MF(MF), LIS(LIS), MBFI(MBFI) {}
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MachineFunction &MF;
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LiveIntervals &LIS;
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MachineBlockFrequencyInfo &MBFI;
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void setNodeIdForVReg(unsigned VReg, GraphBase::NodeId NId) {
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VRegToNodeId[VReg] = NId;
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}
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GraphBase::NodeId getNodeIdForVReg(unsigned VReg) const {
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auto VRegItr = VRegToNodeId.find(VReg);
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if (VRegItr == VRegToNodeId.end())
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return GraphBase::invalidNodeId();
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return VRegItr->second;
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}
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void eraseNodeIdForVReg(unsigned VReg) {
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VRegToNodeId.erase(VReg);
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}
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private:
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DenseMap<unsigned, NodeId> VRegToNodeId;
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};
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typedef PBQP::Graph<RegAllocSolverImpl> Graph;
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RegAllocSolverImpl(Graph &G) : G(G) {}
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Solution solve() {
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G.setSolver(*this);
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Solution S;
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setup();
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S = backpropagate(G, reduce());
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G.unsetSolver();
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return S;
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}
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void handleAddNode(NodeId NId) {
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G.getNodeMetadata(NId).setup(G.getNodeCosts(NId));
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}
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void handleRemoveNode(NodeId NId) {}
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void handleSetNodeCosts(NodeId NId, const Vector& newCosts) {}
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void handleAddEdge(EdgeId EId) {
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handleReconnectEdge(EId, G.getEdgeNode1Id(EId));
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handleReconnectEdge(EId, G.getEdgeNode2Id(EId));
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}
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void handleRemoveEdge(EdgeId EId) {
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handleDisconnectEdge(EId, G.getEdgeNode1Id(EId));
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handleDisconnectEdge(EId, G.getEdgeNode2Id(EId));
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}
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void handleDisconnectEdge(EdgeId EId, NodeId NId) {
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NodeMetadata& NMd = G.getNodeMetadata(NId);
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const MatrixMetadata& MMd = G.getEdgeCosts(EId).getMetadata();
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NMd.handleRemoveEdge(MMd, NId == G.getEdgeNode2Id(EId));
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if (G.getNodeDegree(NId) == 3) {
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// This node is becoming optimally reducible.
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moveToOptimallyReducibleNodes(NId);
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} else if (NMd.getReductionState() ==
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NodeMetadata::NotProvablyAllocatable &&
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NMd.isConservativelyAllocatable()) {
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// This node just became conservatively allocatable.
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moveToConservativelyAllocatableNodes(NId);
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}
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}
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void handleReconnectEdge(EdgeId EId, NodeId NId) {
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NodeMetadata& NMd = G.getNodeMetadata(NId);
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const MatrixMetadata& MMd = G.getEdgeCosts(EId).getMetadata();
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NMd.handleAddEdge(MMd, NId == G.getEdgeNode2Id(EId));
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}
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void handleSetEdgeCosts(EdgeId EId, const Matrix& NewCosts) {
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handleRemoveEdge(EId);
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NodeId N1Id = G.getEdgeNode1Id(EId);
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NodeId N2Id = G.getEdgeNode2Id(EId);
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NodeMetadata& N1Md = G.getNodeMetadata(N1Id);
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NodeMetadata& N2Md = G.getNodeMetadata(N2Id);
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const MatrixMetadata& MMd = NewCosts.getMetadata();
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N1Md.handleAddEdge(MMd, N1Id != G.getEdgeNode1Id(EId));
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N2Md.handleAddEdge(MMd, N2Id != G.getEdgeNode1Id(EId));
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}
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private:
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void removeFromCurrentSet(NodeId NId) {
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switch (G.getNodeMetadata(NId).getReductionState()) {
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case NodeMetadata::Unprocessed: break;
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case NodeMetadata::OptimallyReducible:
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assert(OptimallyReducibleNodes.find(NId) !=
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OptimallyReducibleNodes.end() &&
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"Node not in optimally reducible set.");
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OptimallyReducibleNodes.erase(NId);
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break;
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case NodeMetadata::ConservativelyAllocatable:
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assert(ConservativelyAllocatableNodes.find(NId) !=
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ConservativelyAllocatableNodes.end() &&
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"Node not in conservatively allocatable set.");
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ConservativelyAllocatableNodes.erase(NId);
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break;
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case NodeMetadata::NotProvablyAllocatable:
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assert(NotProvablyAllocatableNodes.find(NId) !=
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NotProvablyAllocatableNodes.end() &&
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"Node not in not-provably-allocatable set.");
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NotProvablyAllocatableNodes.erase(NId);
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break;
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}
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}
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void moveToOptimallyReducibleNodes(NodeId NId) {
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removeFromCurrentSet(NId);
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OptimallyReducibleNodes.insert(NId);
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G.getNodeMetadata(NId).setReductionState(
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NodeMetadata::OptimallyReducible);
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}
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void moveToConservativelyAllocatableNodes(NodeId NId) {
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removeFromCurrentSet(NId);
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ConservativelyAllocatableNodes.insert(NId);
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G.getNodeMetadata(NId).setReductionState(
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NodeMetadata::ConservativelyAllocatable);
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}
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void moveToNotProvablyAllocatableNodes(NodeId NId) {
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removeFromCurrentSet(NId);
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NotProvablyAllocatableNodes.insert(NId);
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G.getNodeMetadata(NId).setReductionState(
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NodeMetadata::NotProvablyAllocatable);
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}
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void setup() {
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// Set up worklists.
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for (auto NId : G.nodeIds()) {
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if (G.getNodeDegree(NId) < 3)
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moveToOptimallyReducibleNodes(NId);
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else if (G.getNodeMetadata(NId).isConservativelyAllocatable())
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moveToConservativelyAllocatableNodes(NId);
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else
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moveToNotProvablyAllocatableNodes(NId);
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}
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}
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// Compute a reduction order for the graph by iteratively applying PBQP
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// reduction rules. Locally optimal rules are applied whenever possible (R0,
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// R1, R2). If no locally-optimal rules apply then any conservatively
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// allocatable node is reduced. Finally, if no conservatively allocatable
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// node exists then the node with the lowest spill-cost:degree ratio is
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// selected.
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std::vector<GraphBase::NodeId> reduce() {
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assert(!G.empty() && "Cannot reduce empty graph.");
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typedef GraphBase::NodeId NodeId;
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std::vector<NodeId> NodeStack;
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// Consume worklists.
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while (true) {
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if (!OptimallyReducibleNodes.empty()) {
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NodeSet::iterator NItr = OptimallyReducibleNodes.begin();
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NodeId NId = *NItr;
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OptimallyReducibleNodes.erase(NItr);
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NodeStack.push_back(NId);
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switch (G.getNodeDegree(NId)) {
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case 0:
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break;
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case 1:
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applyR1(G, NId);
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break;
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case 2:
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applyR2(G, NId);
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break;
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default: llvm_unreachable("Not an optimally reducible node.");
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}
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} else if (!ConservativelyAllocatableNodes.empty()) {
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// Conservatively allocatable nodes will never spill. For now just
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// take the first node in the set and push it on the stack. When we
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// start optimizing more heavily for register preferencing, it may
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// would be better to push nodes with lower 'expected' or worst-case
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// register costs first (since early nodes are the most
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// constrained).
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NodeSet::iterator NItr = ConservativelyAllocatableNodes.begin();
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NodeId NId = *NItr;
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ConservativelyAllocatableNodes.erase(NItr);
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NodeStack.push_back(NId);
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G.disconnectAllNeighborsFromNode(NId);
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} else if (!NotProvablyAllocatableNodes.empty()) {
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NodeSet::iterator NItr =
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std::min_element(NotProvablyAllocatableNodes.begin(),
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NotProvablyAllocatableNodes.end(),
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SpillCostComparator(G));
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NodeId NId = *NItr;
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NotProvablyAllocatableNodes.erase(NItr);
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NodeStack.push_back(NId);
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G.disconnectAllNeighborsFromNode(NId);
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} else
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break;
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}
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return NodeStack;
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}
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class SpillCostComparator {
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public:
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SpillCostComparator(const Graph& G) : G(G) {}
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bool operator()(NodeId N1Id, NodeId N2Id) {
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PBQPNum N1SC = G.getNodeCosts(N1Id)[0] / G.getNodeDegree(N1Id);
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PBQPNum N2SC = G.getNodeCosts(N2Id)[0] / G.getNodeDegree(N2Id);
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return N1SC < N2SC;
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}
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private:
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const Graph& G;
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};
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Graph& G;
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typedef std::set<NodeId> NodeSet;
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NodeSet OptimallyReducibleNodes;
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NodeSet ConservativelyAllocatableNodes;
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NodeSet NotProvablyAllocatableNodes;
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};
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class PBQPRAGraph : public PBQP::Graph<RegAllocSolverImpl> {
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private:
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typedef PBQP::Graph<RegAllocSolverImpl> BaseT;
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public:
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PBQPRAGraph(GraphMetadata Metadata) : BaseT(Metadata) {}
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};
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inline Solution solve(PBQPRAGraph& G) {
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if (G.empty())
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return Solution();
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RegAllocSolverImpl RegAllocSolver(G);
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return RegAllocSolver.solve();
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}
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} // namespace RegAlloc
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} // namespace PBQP
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} // namespace llvm
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#endif // LLVM_CODEGEN_PBQP_REGALLOCSOLVER_H
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@ -18,13 +18,394 @@
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#include "llvm/CodeGen/MachineFunctionPass.h"
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#include "llvm/CodeGen/PBQPRAConstraint.h"
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#include "llvm/CodeGen/PBQP/RegAllocSolver.h"
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#include "llvm/CodeGen/PBQP/CostAllocator.h"
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#include "llvm/CodeGen/PBQP/ReductionRules.h"
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#include "llvm/Support/ErrorHandling.h"
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namespace llvm {
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namespace PBQP {
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namespace RegAlloc {
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/// @brief Create a PBQP register allocator instance.
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FunctionPass *
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createPBQPRegisterAllocator(char *customPassID = nullptr);
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/// @brief Spill option index.
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inline unsigned getSpillOptionIdx() { return 0; }
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/// \brief Metadata to speed allocatability test.
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///
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/// Keeps track of the number of infinities in each row and column.
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class MatrixMetadata {
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private:
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MatrixMetadata(const MatrixMetadata&);
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void operator=(const MatrixMetadata&);
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public:
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MatrixMetadata(const Matrix& M)
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: WorstRow(0), WorstCol(0),
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UnsafeRows(new bool[M.getRows() - 1]()),
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UnsafeCols(new bool[M.getCols() - 1]()) {
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unsigned* ColCounts = new unsigned[M.getCols() - 1]();
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for (unsigned i = 1; i < M.getRows(); ++i) {
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unsigned RowCount = 0;
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for (unsigned j = 1; j < M.getCols(); ++j) {
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if (M[i][j] == std::numeric_limits<PBQPNum>::infinity()) {
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++RowCount;
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++ColCounts[j - 1];
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UnsafeRows[i - 1] = true;
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UnsafeCols[j - 1] = true;
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}
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}
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WorstRow = std::max(WorstRow, RowCount);
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}
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unsigned WorstColCountForCurRow =
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*std::max_element(ColCounts, ColCounts + M.getCols() - 1);
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WorstCol = std::max(WorstCol, WorstColCountForCurRow);
|
||||
delete[] ColCounts;
|
||||
}
|
||||
|
||||
~MatrixMetadata() {
|
||||
delete[] UnsafeRows;
|
||||
delete[] UnsafeCols;
|
||||
}
|
||||
|
||||
unsigned getWorstRow() const { return WorstRow; }
|
||||
unsigned getWorstCol() const { return WorstCol; }
|
||||
const bool* getUnsafeRows() const { return UnsafeRows; }
|
||||
const bool* getUnsafeCols() const { return UnsafeCols; }
|
||||
|
||||
private:
|
||||
unsigned WorstRow, WorstCol;
|
||||
bool* UnsafeRows;
|
||||
bool* UnsafeCols;
|
||||
};
|
||||
|
||||
class NodeMetadata {
|
||||
public:
|
||||
typedef std::vector<unsigned> OptionToRegMap;
|
||||
|
||||
typedef enum { Unprocessed,
|
||||
OptimallyReducible,
|
||||
ConservativelyAllocatable,
|
||||
NotProvablyAllocatable } ReductionState;
|
||||
|
||||
NodeMetadata() : RS(Unprocessed), DeniedOpts(0), OptUnsafeEdges(nullptr){}
|
||||
~NodeMetadata() { delete[] OptUnsafeEdges; }
|
||||
|
||||
void setVReg(unsigned VReg) { this->VReg = VReg; }
|
||||
unsigned getVReg() const { return VReg; }
|
||||
|
||||
void setOptionRegs(OptionToRegMap OptionRegs) {
|
||||
this->OptionRegs = std::move(OptionRegs);
|
||||
}
|
||||
const OptionToRegMap& getOptionRegs() const { return OptionRegs; }
|
||||
|
||||
void setup(const Vector& Costs) {
|
||||
NumOpts = Costs.getLength() - 1;
|
||||
OptUnsafeEdges = new unsigned[NumOpts]();
|
||||
}
|
||||
|
||||
ReductionState getReductionState() const { return RS; }
|
||||
void setReductionState(ReductionState RS) { this->RS = RS; }
|
||||
|
||||
void handleAddEdge(const MatrixMetadata& MD, bool Transpose) {
|
||||
DeniedOpts += Transpose ? MD.getWorstCol() : MD.getWorstRow();
|
||||
const bool* UnsafeOpts =
|
||||
Transpose ? MD.getUnsafeCols() : MD.getUnsafeRows();
|
||||
for (unsigned i = 0; i < NumOpts; ++i)
|
||||
OptUnsafeEdges[i] += UnsafeOpts[i];
|
||||
}
|
||||
|
||||
void handleRemoveEdge(const MatrixMetadata& MD, bool Transpose) {
|
||||
DeniedOpts -= Transpose ? MD.getWorstCol() : MD.getWorstRow();
|
||||
const bool* UnsafeOpts =
|
||||
Transpose ? MD.getUnsafeCols() : MD.getUnsafeRows();
|
||||
for (unsigned i = 0; i < NumOpts; ++i)
|
||||
OptUnsafeEdges[i] -= UnsafeOpts[i];
|
||||
}
|
||||
|
||||
bool isConservativelyAllocatable() const {
|
||||
return (DeniedOpts < NumOpts) ||
|
||||
(std::find(OptUnsafeEdges, OptUnsafeEdges + NumOpts, 0) !=
|
||||
OptUnsafeEdges + NumOpts);
|
||||
}
|
||||
|
||||
private:
|
||||
ReductionState RS;
|
||||
unsigned NumOpts;
|
||||
unsigned DeniedOpts;
|
||||
unsigned* OptUnsafeEdges;
|
||||
unsigned VReg;
|
||||
OptionToRegMap OptionRegs;
|
||||
};
|
||||
|
||||
class RegAllocSolverImpl {
|
||||
private:
|
||||
typedef MDMatrix<MatrixMetadata> RAMatrix;
|
||||
public:
|
||||
typedef PBQP::Vector RawVector;
|
||||
typedef PBQP::Matrix RawMatrix;
|
||||
typedef PBQP::Vector Vector;
|
||||
typedef RAMatrix Matrix;
|
||||
typedef PBQP::PoolCostAllocator<
|
||||
Vector, PBQP::VectorComparator,
|
||||
Matrix, PBQP::MatrixComparator> CostAllocator;
|
||||
|
||||
typedef GraphBase::NodeId NodeId;
|
||||
typedef GraphBase::EdgeId EdgeId;
|
||||
|
||||
typedef RegAlloc::NodeMetadata NodeMetadata;
|
||||
|
||||
struct EdgeMetadata { };
|
||||
|
||||
class GraphMetadata {
|
||||
public:
|
||||
GraphMetadata(MachineFunction &MF,
|
||||
LiveIntervals &LIS,
|
||||
MachineBlockFrequencyInfo &MBFI)
|
||||
: MF(MF), LIS(LIS), MBFI(MBFI) {}
|
||||
|
||||
MachineFunction &MF;
|
||||
LiveIntervals &LIS;
|
||||
MachineBlockFrequencyInfo &MBFI;
|
||||
|
||||
void setNodeIdForVReg(unsigned VReg, GraphBase::NodeId NId) {
|
||||
VRegToNodeId[VReg] = NId;
|
||||
}
|
||||
|
||||
GraphBase::NodeId getNodeIdForVReg(unsigned VReg) const {
|
||||
auto VRegItr = VRegToNodeId.find(VReg);
|
||||
if (VRegItr == VRegToNodeId.end())
|
||||
return GraphBase::invalidNodeId();
|
||||
return VRegItr->second;
|
||||
}
|
||||
|
||||
void eraseNodeIdForVReg(unsigned VReg) {
|
||||
VRegToNodeId.erase(VReg);
|
||||
}
|
||||
|
||||
private:
|
||||
DenseMap<unsigned, NodeId> VRegToNodeId;
|
||||
};
|
||||
|
||||
typedef PBQP::Graph<RegAllocSolverImpl> Graph;
|
||||
|
||||
RegAllocSolverImpl(Graph &G) : G(G) {}
|
||||
|
||||
Solution solve() {
|
||||
G.setSolver(*this);
|
||||
Solution S;
|
||||
setup();
|
||||
S = backpropagate(G, reduce());
|
||||
G.unsetSolver();
|
||||
return S;
|
||||
}
|
||||
|
||||
void handleAddNode(NodeId NId) {
|
||||
G.getNodeMetadata(NId).setup(G.getNodeCosts(NId));
|
||||
}
|
||||
void handleRemoveNode(NodeId NId) {}
|
||||
void handleSetNodeCosts(NodeId NId, const Vector& newCosts) {}
|
||||
|
||||
void handleAddEdge(EdgeId EId) {
|
||||
handleReconnectEdge(EId, G.getEdgeNode1Id(EId));
|
||||
handleReconnectEdge(EId, G.getEdgeNode2Id(EId));
|
||||
}
|
||||
|
||||
void handleRemoveEdge(EdgeId EId) {
|
||||
handleDisconnectEdge(EId, G.getEdgeNode1Id(EId));
|
||||
handleDisconnectEdge(EId, G.getEdgeNode2Id(EId));
|
||||
}
|
||||
|
||||
void handleDisconnectEdge(EdgeId EId, NodeId NId) {
|
||||
NodeMetadata& NMd = G.getNodeMetadata(NId);
|
||||
const MatrixMetadata& MMd = G.getEdgeCosts(EId).getMetadata();
|
||||
NMd.handleRemoveEdge(MMd, NId == G.getEdgeNode2Id(EId));
|
||||
if (G.getNodeDegree(NId) == 3) {
|
||||
// This node is becoming optimally reducible.
|
||||
moveToOptimallyReducibleNodes(NId);
|
||||
} else if (NMd.getReductionState() ==
|
||||
NodeMetadata::NotProvablyAllocatable &&
|
||||
NMd.isConservativelyAllocatable()) {
|
||||
// This node just became conservatively allocatable.
|
||||
moveToConservativelyAllocatableNodes(NId);
|
||||
}
|
||||
}
|
||||
|
||||
void handleReconnectEdge(EdgeId EId, NodeId NId) {
|
||||
NodeMetadata& NMd = G.getNodeMetadata(NId);
|
||||
const MatrixMetadata& MMd = G.getEdgeCosts(EId).getMetadata();
|
||||
NMd.handleAddEdge(MMd, NId == G.getEdgeNode2Id(EId));
|
||||
}
|
||||
|
||||
void handleSetEdgeCosts(EdgeId EId, const Matrix& NewCosts) {
|
||||
handleRemoveEdge(EId);
|
||||
|
||||
NodeId N1Id = G.getEdgeNode1Id(EId);
|
||||
NodeId N2Id = G.getEdgeNode2Id(EId);
|
||||
NodeMetadata& N1Md = G.getNodeMetadata(N1Id);
|
||||
NodeMetadata& N2Md = G.getNodeMetadata(N2Id);
|
||||
const MatrixMetadata& MMd = NewCosts.getMetadata();
|
||||
N1Md.handleAddEdge(MMd, N1Id != G.getEdgeNode1Id(EId));
|
||||
N2Md.handleAddEdge(MMd, N2Id != G.getEdgeNode1Id(EId));
|
||||
}
|
||||
|
||||
private:
|
||||
|
||||
void removeFromCurrentSet(NodeId NId) {
|
||||
switch (G.getNodeMetadata(NId).getReductionState()) {
|
||||
case NodeMetadata::Unprocessed: break;
|
||||
case NodeMetadata::OptimallyReducible:
|
||||
assert(OptimallyReducibleNodes.find(NId) !=
|
||||
OptimallyReducibleNodes.end() &&
|
||||
"Node not in optimally reducible set.");
|
||||
OptimallyReducibleNodes.erase(NId);
|
||||
break;
|
||||
case NodeMetadata::ConservativelyAllocatable:
|
||||
assert(ConservativelyAllocatableNodes.find(NId) !=
|
||||
ConservativelyAllocatableNodes.end() &&
|
||||
"Node not in conservatively allocatable set.");
|
||||
ConservativelyAllocatableNodes.erase(NId);
|
||||
break;
|
||||
case NodeMetadata::NotProvablyAllocatable:
|
||||
assert(NotProvablyAllocatableNodes.find(NId) !=
|
||||
NotProvablyAllocatableNodes.end() &&
|
||||
"Node not in not-provably-allocatable set.");
|
||||
NotProvablyAllocatableNodes.erase(NId);
|
||||
break;
|
||||
}
|
||||
}
|
||||
|
||||
void moveToOptimallyReducibleNodes(NodeId NId) {
|
||||
removeFromCurrentSet(NId);
|
||||
OptimallyReducibleNodes.insert(NId);
|
||||
G.getNodeMetadata(NId).setReductionState(
|
||||
NodeMetadata::OptimallyReducible);
|
||||
}
|
||||
|
||||
void moveToConservativelyAllocatableNodes(NodeId NId) {
|
||||
removeFromCurrentSet(NId);
|
||||
ConservativelyAllocatableNodes.insert(NId);
|
||||
G.getNodeMetadata(NId).setReductionState(
|
||||
NodeMetadata::ConservativelyAllocatable);
|
||||
}
|
||||
|
||||
void moveToNotProvablyAllocatableNodes(NodeId NId) {
|
||||
removeFromCurrentSet(NId);
|
||||
NotProvablyAllocatableNodes.insert(NId);
|
||||
G.getNodeMetadata(NId).setReductionState(
|
||||
NodeMetadata::NotProvablyAllocatable);
|
||||
}
|
||||
|
||||
void setup() {
|
||||
// Set up worklists.
|
||||
for (auto NId : G.nodeIds()) {
|
||||
if (G.getNodeDegree(NId) < 3)
|
||||
moveToOptimallyReducibleNodes(NId);
|
||||
else if (G.getNodeMetadata(NId).isConservativelyAllocatable())
|
||||
moveToConservativelyAllocatableNodes(NId);
|
||||
else
|
||||
moveToNotProvablyAllocatableNodes(NId);
|
||||
}
|
||||
}
|
||||
|
||||
// Compute a reduction order for the graph by iteratively applying PBQP
|
||||
// reduction rules. Locally optimal rules are applied whenever possible (R0,
|
||||
// R1, R2). If no locally-optimal rules apply then any conservatively
|
||||
// allocatable node is reduced. Finally, if no conservatively allocatable
|
||||
// node exists then the node with the lowest spill-cost:degree ratio is
|
||||
// selected.
|
||||
std::vector<GraphBase::NodeId> reduce() {
|
||||
assert(!G.empty() && "Cannot reduce empty graph.");
|
||||
|
||||
typedef GraphBase::NodeId NodeId;
|
||||
std::vector<NodeId> NodeStack;
|
||||
|
||||
// Consume worklists.
|
||||
while (true) {
|
||||
if (!OptimallyReducibleNodes.empty()) {
|
||||
NodeSet::iterator NItr = OptimallyReducibleNodes.begin();
|
||||
NodeId NId = *NItr;
|
||||
OptimallyReducibleNodes.erase(NItr);
|
||||
NodeStack.push_back(NId);
|
||||
switch (G.getNodeDegree(NId)) {
|
||||
case 0:
|
||||
break;
|
||||
case 1:
|
||||
applyR1(G, NId);
|
||||
break;
|
||||
case 2:
|
||||
applyR2(G, NId);
|
||||
break;
|
||||
default: llvm_unreachable("Not an optimally reducible node.");
|
||||
}
|
||||
} else if (!ConservativelyAllocatableNodes.empty()) {
|
||||
// Conservatively allocatable nodes will never spill. For now just
|
||||
// take the first node in the set and push it on the stack. When we
|
||||
// start optimizing more heavily for register preferencing, it may
|
||||
// would be better to push nodes with lower 'expected' or worst-case
|
||||
// register costs first (since early nodes are the most
|
||||
// constrained).
|
||||
NodeSet::iterator NItr = ConservativelyAllocatableNodes.begin();
|
||||
NodeId NId = *NItr;
|
||||
ConservativelyAllocatableNodes.erase(NItr);
|
||||
NodeStack.push_back(NId);
|
||||
G.disconnectAllNeighborsFromNode(NId);
|
||||
|
||||
} else if (!NotProvablyAllocatableNodes.empty()) {
|
||||
NodeSet::iterator NItr =
|
||||
std::min_element(NotProvablyAllocatableNodes.begin(),
|
||||
NotProvablyAllocatableNodes.end(),
|
||||
SpillCostComparator(G));
|
||||
NodeId NId = *NItr;
|
||||
NotProvablyAllocatableNodes.erase(NItr);
|
||||
NodeStack.push_back(NId);
|
||||
G.disconnectAllNeighborsFromNode(NId);
|
||||
} else
|
||||
break;
|
||||
}
|
||||
|
||||
return NodeStack;
|
||||
}
|
||||
|
||||
class SpillCostComparator {
|
||||
public:
|
||||
SpillCostComparator(const Graph& G) : G(G) {}
|
||||
bool operator()(NodeId N1Id, NodeId N2Id) {
|
||||
PBQPNum N1SC = G.getNodeCosts(N1Id)[0] / G.getNodeDegree(N1Id);
|
||||
PBQPNum N2SC = G.getNodeCosts(N2Id)[0] / G.getNodeDegree(N2Id);
|
||||
return N1SC < N2SC;
|
||||
}
|
||||
private:
|
||||
const Graph& G;
|
||||
};
|
||||
|
||||
Graph& G;
|
||||
typedef std::set<NodeId> NodeSet;
|
||||
NodeSet OptimallyReducibleNodes;
|
||||
NodeSet ConservativelyAllocatableNodes;
|
||||
NodeSet NotProvablyAllocatableNodes;
|
||||
};
|
||||
|
||||
class PBQPRAGraph : public PBQP::Graph<RegAllocSolverImpl> {
|
||||
private:
|
||||
typedef PBQP::Graph<RegAllocSolverImpl> BaseT;
|
||||
public:
|
||||
PBQPRAGraph(GraphMetadata Metadata) : BaseT(Metadata) {}
|
||||
};
|
||||
|
||||
inline Solution solve(PBQPRAGraph& G) {
|
||||
if (G.empty())
|
||||
return Solution();
|
||||
RegAllocSolverImpl RegAllocSolver(G);
|
||||
return RegAllocSolver.solve();
|
||||
}
|
||||
|
||||
} // namespace RegAlloc
|
||||
} // namespace PBQP
|
||||
|
||||
/// @brief Create a PBQP register allocator instance.
|
||||
FunctionPass *
|
||||
createPBQPRegisterAllocator(char *customPassID = nullptr);
|
||||
|
||||
} // namespace llvm
|
||||
|
||||
#endif /* LLVM_CODEGEN_REGALLOCPBQP_H */
|
||||
|
||||
Loading…
Reference in New Issue
Block a user