mirror of
https://github.com/RPCS3/llvm-mirror.git
synced 2024-11-23 11:13:28 +01:00
0489ce9303
This is a follow-up to r331272. We've been running doxygen with the autobrief option for a couple of years now. This makes the \brief markers into our comments redundant. Since they are a visual distraction and we don't want to encourage more \brief markers in new code either, this patch removes them all. Patch produced by for i in $(git grep -l '\@brief'); do perl -pi -e 's/\@brief //g' $i & done https://reviews.llvm.org/D46290 llvm-svn: 331275
537 lines
16 KiB
C++
537 lines
16 KiB
C++
//===- RegAllocPBQP.h -------------------------------------------*- C++ -*-===//
|
|
//
|
|
// The LLVM Compiler Infrastructure
|
|
//
|
|
// This file is distributed under the University of Illinois Open Source
|
|
// License. See LICENSE.TXT for details.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
//
|
|
// This file defines the PBQPBuilder interface, for classes which build PBQP
|
|
// instances to represent register allocation problems, and the RegAllocPBQP
|
|
// interface.
|
|
//
|
|
//===----------------------------------------------------------------------===//
|
|
|
|
#ifndef LLVM_CODEGEN_REGALLOCPBQP_H
|
|
#define LLVM_CODEGEN_REGALLOCPBQP_H
|
|
|
|
#include "llvm/ADT/DenseMap.h"
|
|
#include "llvm/ADT/Hashing.h"
|
|
#include "llvm/CodeGen/PBQP/CostAllocator.h"
|
|
#include "llvm/CodeGen/PBQP/Graph.h"
|
|
#include "llvm/CodeGen/PBQP/Math.h"
|
|
#include "llvm/CodeGen/PBQP/ReductionRules.h"
|
|
#include "llvm/CodeGen/PBQP/Solution.h"
|
|
#include "llvm/Support/ErrorHandling.h"
|
|
#include <algorithm>
|
|
#include <cassert>
|
|
#include <cstddef>
|
|
#include <limits>
|
|
#include <memory>
|
|
#include <set>
|
|
#include <vector>
|
|
|
|
namespace llvm {
|
|
|
|
class FunctionPass;
|
|
class LiveIntervals;
|
|
class MachineBlockFrequencyInfo;
|
|
class MachineFunction;
|
|
class raw_ostream;
|
|
|
|
namespace PBQP {
|
|
namespace RegAlloc {
|
|
|
|
/// Spill option index.
|
|
inline unsigned getSpillOptionIdx() { return 0; }
|
|
|
|
/// Metadata to speed allocatability test.
|
|
///
|
|
/// Keeps track of the number of infinities in each row and column.
|
|
class MatrixMetadata {
|
|
public:
|
|
MatrixMetadata(const Matrix& M)
|
|
: UnsafeRows(new bool[M.getRows() - 1]()),
|
|
UnsafeCols(new bool[M.getCols() - 1]()) {
|
|
unsigned* ColCounts = new unsigned[M.getCols() - 1]();
|
|
|
|
for (unsigned i = 1; i < M.getRows(); ++i) {
|
|
unsigned RowCount = 0;
|
|
for (unsigned j = 1; j < M.getCols(); ++j) {
|
|
if (M[i][j] == std::numeric_limits<PBQPNum>::infinity()) {
|
|
++RowCount;
|
|
++ColCounts[j - 1];
|
|
UnsafeRows[i - 1] = true;
|
|
UnsafeCols[j - 1] = true;
|
|
}
|
|
}
|
|
WorstRow = std::max(WorstRow, RowCount);
|
|
}
|
|
unsigned WorstColCountForCurRow =
|
|
*std::max_element(ColCounts, ColCounts + M.getCols() - 1);
|
|
WorstCol = std::max(WorstCol, WorstColCountForCurRow);
|
|
delete[] ColCounts;
|
|
}
|
|
|
|
MatrixMetadata(const MatrixMetadata &) = delete;
|
|
MatrixMetadata &operator=(const MatrixMetadata &) = delete;
|
|
|
|
unsigned getWorstRow() const { return WorstRow; }
|
|
unsigned getWorstCol() const { return WorstCol; }
|
|
const bool* getUnsafeRows() const { return UnsafeRows.get(); }
|
|
const bool* getUnsafeCols() const { return UnsafeCols.get(); }
|
|
|
|
private:
|
|
unsigned WorstRow = 0;
|
|
unsigned WorstCol = 0;
|
|
std::unique_ptr<bool[]> UnsafeRows;
|
|
std::unique_ptr<bool[]> UnsafeCols;
|
|
};
|
|
|
|
/// Holds a vector of the allowed physical regs for a vreg.
|
|
class AllowedRegVector {
|
|
friend hash_code hash_value(const AllowedRegVector &);
|
|
|
|
public:
|
|
AllowedRegVector() = default;
|
|
AllowedRegVector(AllowedRegVector &&) = default;
|
|
|
|
AllowedRegVector(const std::vector<unsigned> &OptVec)
|
|
: NumOpts(OptVec.size()), Opts(new unsigned[NumOpts]) {
|
|
std::copy(OptVec.begin(), OptVec.end(), Opts.get());
|
|
}
|
|
|
|
unsigned size() const { return NumOpts; }
|
|
unsigned operator[](size_t I) const { return Opts[I]; }
|
|
|
|
bool operator==(const AllowedRegVector &Other) const {
|
|
if (NumOpts != Other.NumOpts)
|
|
return false;
|
|
return std::equal(Opts.get(), Opts.get() + NumOpts, Other.Opts.get());
|
|
}
|
|
|
|
bool operator!=(const AllowedRegVector &Other) const {
|
|
return !(*this == Other);
|
|
}
|
|
|
|
private:
|
|
unsigned NumOpts = 0;
|
|
std::unique_ptr<unsigned[]> Opts;
|
|
};
|
|
|
|
inline hash_code hash_value(const AllowedRegVector &OptRegs) {
|
|
unsigned *OStart = OptRegs.Opts.get();
|
|
unsigned *OEnd = OptRegs.Opts.get() + OptRegs.NumOpts;
|
|
return hash_combine(OptRegs.NumOpts,
|
|
hash_combine_range(OStart, OEnd));
|
|
}
|
|
|
|
/// Holds graph-level metadata relevant to PBQP RA problems.
|
|
class GraphMetadata {
|
|
private:
|
|
using AllowedRegVecPool = ValuePool<AllowedRegVector>;
|
|
|
|
public:
|
|
using AllowedRegVecRef = AllowedRegVecPool::PoolRef;
|
|
|
|
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;
|
|
}
|
|
|
|
AllowedRegVecRef getAllowedRegs(AllowedRegVector Allowed) {
|
|
return AllowedRegVecs.getValue(std::move(Allowed));
|
|
}
|
|
|
|
private:
|
|
DenseMap<unsigned, GraphBase::NodeId> VRegToNodeId;
|
|
AllowedRegVecPool AllowedRegVecs;
|
|
};
|
|
|
|
/// Holds solver state and other metadata relevant to each PBQP RA node.
|
|
class NodeMetadata {
|
|
public:
|
|
using AllowedRegVector = RegAlloc::AllowedRegVector;
|
|
|
|
// The node's reduction state. The order in this enum is important,
|
|
// as it is assumed nodes can only progress up (i.e. towards being
|
|
// optimally reducible) when reducing the graph.
|
|
using ReductionState = enum {
|
|
Unprocessed,
|
|
NotProvablyAllocatable,
|
|
ConservativelyAllocatable,
|
|
OptimallyReducible
|
|
};
|
|
|
|
NodeMetadata() = default;
|
|
|
|
NodeMetadata(const NodeMetadata &Other)
|
|
: RS(Other.RS), NumOpts(Other.NumOpts), DeniedOpts(Other.DeniedOpts),
|
|
OptUnsafeEdges(new unsigned[NumOpts]), VReg(Other.VReg),
|
|
AllowedRegs(Other.AllowedRegs)
|
|
#ifndef NDEBUG
|
|
, everConservativelyAllocatable(Other.everConservativelyAllocatable)
|
|
#endif
|
|
{
|
|
if (NumOpts > 0) {
|
|
std::copy(&Other.OptUnsafeEdges[0], &Other.OptUnsafeEdges[NumOpts],
|
|
&OptUnsafeEdges[0]);
|
|
}
|
|
}
|
|
|
|
NodeMetadata(NodeMetadata &&) = default;
|
|
NodeMetadata& operator=(NodeMetadata &&) = default;
|
|
|
|
void setVReg(unsigned VReg) { this->VReg = VReg; }
|
|
unsigned getVReg() const { return VReg; }
|
|
|
|
void setAllowedRegs(GraphMetadata::AllowedRegVecRef AllowedRegs) {
|
|
this->AllowedRegs = std::move(AllowedRegs);
|
|
}
|
|
const AllowedRegVector& getAllowedRegs() const { return *AllowedRegs; }
|
|
|
|
void setup(const Vector& Costs) {
|
|
NumOpts = Costs.getLength() - 1;
|
|
OptUnsafeEdges = std::unique_ptr<unsigned[]>(new unsigned[NumOpts]());
|
|
}
|
|
|
|
ReductionState getReductionState() const { return RS; }
|
|
void setReductionState(ReductionState RS) {
|
|
assert(RS >= this->RS && "A node's reduction state can not be downgraded");
|
|
this->RS = RS;
|
|
|
|
#ifndef NDEBUG
|
|
// Remember this state to assert later that a non-infinite register
|
|
// option was available.
|
|
if (RS == ConservativelyAllocatable)
|
|
everConservativelyAllocatable = true;
|
|
#endif
|
|
}
|
|
|
|
void handleAddEdge(const MatrixMetadata& MD, bool Transpose) {
|
|
DeniedOpts += Transpose ? MD.getWorstRow() : MD.getWorstCol();
|
|
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.getWorstRow() : MD.getWorstCol();
|
|
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[0], &OptUnsafeEdges[NumOpts], 0) !=
|
|
&OptUnsafeEdges[NumOpts]);
|
|
}
|
|
|
|
#ifndef NDEBUG
|
|
bool wasConservativelyAllocatable() const {
|
|
return everConservativelyAllocatable;
|
|
}
|
|
#endif
|
|
|
|
private:
|
|
ReductionState RS = Unprocessed;
|
|
unsigned NumOpts = 0;
|
|
unsigned DeniedOpts = 0;
|
|
std::unique_ptr<unsigned[]> OptUnsafeEdges;
|
|
unsigned VReg = 0;
|
|
GraphMetadata::AllowedRegVecRef AllowedRegs;
|
|
|
|
#ifndef NDEBUG
|
|
bool everConservativelyAllocatable = false;
|
|
#endif
|
|
};
|
|
|
|
class RegAllocSolverImpl {
|
|
private:
|
|
using RAMatrix = MDMatrix<MatrixMetadata>;
|
|
|
|
public:
|
|
using RawVector = PBQP::Vector;
|
|
using RawMatrix = PBQP::Matrix;
|
|
using Vector = PBQP::Vector;
|
|
using Matrix = RAMatrix;
|
|
using CostAllocator = PBQP::PoolCostAllocator<Vector, Matrix>;
|
|
|
|
using NodeId = GraphBase::NodeId;
|
|
using EdgeId = GraphBase::EdgeId;
|
|
|
|
using NodeMetadata = RegAlloc::NodeMetadata;
|
|
struct EdgeMetadata {};
|
|
using GraphMetadata = RegAlloc::GraphMetadata;
|
|
|
|
using Graph = PBQP::Graph<RegAllocSolverImpl>;
|
|
|
|
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) {
|
|
assert(G.getNodeCosts(NId).getLength() > 1 &&
|
|
"PBQP Graph should not contain single or zero-option nodes");
|
|
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 handleDisconnectEdge(EdgeId EId, NodeId NId) {
|
|
NodeMetadata& NMd = G.getNodeMetadata(NId);
|
|
const MatrixMetadata& MMd = G.getEdgeCosts(EId).getMetadata();
|
|
NMd.handleRemoveEdge(MMd, NId == G.getEdgeNode2Id(EId));
|
|
promote(NId, NMd);
|
|
}
|
|
|
|
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 handleUpdateCosts(EdgeId EId, const Matrix& NewCosts) {
|
|
NodeId N1Id = G.getEdgeNode1Id(EId);
|
|
NodeId N2Id = G.getEdgeNode2Id(EId);
|
|
NodeMetadata& N1Md = G.getNodeMetadata(N1Id);
|
|
NodeMetadata& N2Md = G.getNodeMetadata(N2Id);
|
|
bool Transpose = N1Id != G.getEdgeNode1Id(EId);
|
|
|
|
// Metadata are computed incrementally. First, update them
|
|
// by removing the old cost.
|
|
const MatrixMetadata& OldMMd = G.getEdgeCosts(EId).getMetadata();
|
|
N1Md.handleRemoveEdge(OldMMd, Transpose);
|
|
N2Md.handleRemoveEdge(OldMMd, !Transpose);
|
|
|
|
// And update now the metadata with the new cost.
|
|
const MatrixMetadata& MMd = NewCosts.getMetadata();
|
|
N1Md.handleAddEdge(MMd, Transpose);
|
|
N2Md.handleAddEdge(MMd, !Transpose);
|
|
|
|
// As the metadata may have changed with the update, the nodes may have
|
|
// become ConservativelyAllocatable or OptimallyReducible.
|
|
promote(N1Id, N1Md);
|
|
promote(N2Id, N2Md);
|
|
}
|
|
|
|
private:
|
|
void promote(NodeId NId, NodeMetadata& NMd) {
|
|
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 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.");
|
|
|
|
using NodeId = GraphBase::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];
|
|
PBQPNum N2SC = G.getNodeCosts(N2Id)[0];
|
|
if (N1SC == N2SC)
|
|
return G.getNodeDegree(N1Id) < G.getNodeDegree(N2Id);
|
|
return N1SC < N2SC;
|
|
}
|
|
|
|
private:
|
|
const Graph& G;
|
|
};
|
|
|
|
Graph& G;
|
|
using NodeSet = std::set<NodeId>;
|
|
NodeSet OptimallyReducibleNodes;
|
|
NodeSet ConservativelyAllocatableNodes;
|
|
NodeSet NotProvablyAllocatableNodes;
|
|
};
|
|
|
|
class PBQPRAGraph : public PBQP::Graph<RegAllocSolverImpl> {
|
|
private:
|
|
using BaseT = PBQP::Graph<RegAllocSolverImpl>;
|
|
|
|
public:
|
|
PBQPRAGraph(GraphMetadata Metadata) : BaseT(std::move(Metadata)) {}
|
|
|
|
/// Dump this graph to dbgs().
|
|
void dump() const;
|
|
|
|
/// Dump this graph to an output stream.
|
|
/// @param OS Output stream to print on.
|
|
void dump(raw_ostream &OS) const;
|
|
|
|
/// Print a representation of this graph in DOT format.
|
|
/// @param OS Output stream to print on.
|
|
void printDot(raw_ostream &OS) const;
|
|
};
|
|
|
|
inline Solution solve(PBQPRAGraph& G) {
|
|
if (G.empty())
|
|
return Solution();
|
|
RegAllocSolverImpl RegAllocSolver(G);
|
|
return RegAllocSolver.solve();
|
|
}
|
|
|
|
} // end namespace RegAlloc
|
|
} // end namespace PBQP
|
|
|
|
/// Create a PBQP register allocator instance.
|
|
FunctionPass *
|
|
createPBQPRegisterAllocator(char *customPassID = nullptr);
|
|
|
|
} // end namespace llvm
|
|
|
|
#endif // LLVM_CODEGEN_REGALLOCPBQP_H
|