//===- RDFLiveness.h --------------------------------------------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// Recalculate the liveness information given a data flow graph.
// This includes block live-ins and kill flags.
#ifndef LLVM_CODEGEN_RDFLIVENESS_H
#define LLVM_CODEGEN_RDFLIVENESS_H
#include "RDFGraph.h"
#include "RDFRegisters.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/MC/LaneBitmask.h"
#include <map>
#include <set>
#include <unordered_map>
#include <unordered_set>
#include <utility>
namespace llvm {
class MachineBasicBlock;
class MachineDominanceFrontier;
class MachineDominatorTree;
class MachineRegisterInfo;
class TargetRegisterInfo;
} // namespace llvm
namespace llvm {
namespace rdf {
namespace detail {
using NodeRef = std::pair<NodeId, LaneBitmask>;
} // namespace detail
} // namespace rdf
} // namespace llvm
namespace std {
template <> struct hash<llvm::rdf::detail::NodeRef> {
std::size_t operator()(llvm::rdf::detail::NodeRef R) const {
return std::hash<llvm::rdf::NodeId>{}(R.first) ^
std::hash<llvm::LaneBitmask::Type>{}(R.second.getAsInteger());
}
};
} // namespace std
namespace llvm {
namespace rdf {
struct Liveness {
public:
// This is really a std::map, except that it provides a non-trivial
// default constructor to the element accessed via [].
struct LiveMapType {
LiveMapType(const PhysicalRegisterInfo &pri) : Empty(pri) {}
RegisterAggr &operator[] (MachineBasicBlock *B) {
return Map.emplace(B, Empty).first->second;
}
private:
RegisterAggr Empty;
std::map<MachineBasicBlock*,RegisterAggr> Map;
};
using NodeRef = detail::NodeRef;
using NodeRefSet = std::unordered_set<NodeRef>;
using RefMap = std::unordered_map<RegisterId, NodeRefSet>;
Liveness(MachineRegisterInfo &mri, const DataFlowGraph &g)
: DFG(g), TRI(g.getTRI()), PRI(g.getPRI()), MDT(g.getDT()),
MDF(g.getDF()), LiveMap(g.getPRI()), Empty(), NoRegs(g.getPRI()) {}
NodeList getAllReachingDefs(RegisterRef RefRR, NodeAddr<RefNode*> RefA,
bool TopShadows, bool FullChain, const RegisterAggr &DefRRs);
NodeList getAllReachingDefs(NodeAddr<RefNode*> RefA) {
return getAllReachingDefs(RefA.Addr->getRegRef(DFG), RefA, false,
false, NoRegs);
}
NodeList getAllReachingDefs(RegisterRef RefRR, NodeAddr<RefNode*> RefA) {
return getAllReachingDefs(RefRR, RefA, false, false, NoRegs);
}
NodeSet getAllReachedUses(RegisterRef RefRR, NodeAddr<DefNode*> DefA,
const RegisterAggr &DefRRs);
NodeSet getAllReachedUses(RegisterRef RefRR, NodeAddr<DefNode*> DefA) {
return getAllReachedUses(RefRR, DefA, NoRegs);
}
std::pair<NodeSet,bool> getAllReachingDefsRec(RegisterRef RefRR,
NodeAddr<RefNode*> RefA, NodeSet &Visited, const NodeSet &Defs);
NodeAddr<RefNode*> getNearestAliasedRef(RegisterRef RefRR,
NodeAddr<InstrNode*> IA);
LiveMapType &getLiveMap() { return LiveMap; }
const LiveMapType &getLiveMap() const { return LiveMap; }
const RefMap &getRealUses(NodeId P) const {
auto F = RealUseMap.find(P);
return F == RealUseMap.end() ? Empty : F->second;
}
void computePhiInfo();
void computeLiveIns();
void resetLiveIns();
void resetKills();
void resetKills(MachineBasicBlock *B);
void trace(bool T) { Trace = T; }
private:
const DataFlowGraph &DFG;
const TargetRegisterInfo &TRI;
const PhysicalRegisterInfo &PRI;
const MachineDominatorTree &MDT;
const MachineDominanceFrontier &MDF;
LiveMapType LiveMap;
const RefMap Empty;
const RegisterAggr NoRegs;
bool Trace = false;
// Cache of mapping from node ids (for RefNodes) to the containing
// basic blocks. Not computing it each time for each node reduces
// the liveness calculation time by a large fraction.
DenseMap<NodeId, MachineBasicBlock *> NBMap;
// Phi information:
//
// RealUseMap
// map: NodeId -> (map: RegisterId -> NodeRefSet)
// phi id -> (map: register -> set of reached non-phi uses)
DenseMap<NodeId, RefMap> RealUseMap;
// Inverse iterated dominance frontier.
std::map<MachineBasicBlock*,std::set<MachineBasicBlock*>> IIDF;
// Live on entry.
std::map<MachineBasicBlock*,RefMap> PhiLON;
// Phi uses are considered to be located at the end of the block that
// they are associated with. The reaching def of a phi use dominates the
// block that the use corresponds to, but not the block that contains
// the phi itself. To include these uses in the liveness propagation (up
// the dominator tree), create a map: block -> set of uses live on exit.
std::map<MachineBasicBlock*,RefMap> PhiLOX;
MachineBasicBlock *getBlockWithRef(NodeId RN) const;
void traverse(MachineBasicBlock *B, RefMap &LiveIn);
void emptify(RefMap &M);
std::pair<NodeSet,bool> getAllReachingDefsRecImpl(RegisterRef RefRR,
NodeAddr<RefNode*> RefA, NodeSet &Visited, const NodeSet &Defs,
unsigned Nest, unsigned MaxNest);
};
raw_ostream &operator<<(raw_ostream &OS, const Print<Liveness::RefMap> &P);
} // end namespace rdf
} // end namespace llvm
#endif // LLVM_CODEGEN_RDFLIVENESS_H