#define CODEGEN_REGISTERS_H
#include "SetTheory.h"
-#include "llvm/TableGen/Record.h"
-#include "llvm/CodeGen/ValueTypes.h"
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/BitVector.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/SetVector.h"
+#include "llvm/CodeGen/ValueTypes.h"
#include "llvm/Support/ErrorHandling.h"
+#include "llvm/TableGen/Record.h"
#include <cstdlib>
#include <map>
-#include <string>
#include <set>
+#include <string>
#include <vector>
namespace llvm {
/// CodeGenSubRegIndex - Represents a sub-register index.
class CodeGenSubRegIndex {
Record *const TheDef;
- const unsigned EnumValue;
+ std::string Name;
+ std::string Namespace;
public:
+ uint16_t Size;
+ uint16_t Offset;
+ const unsigned EnumValue;
+ unsigned LaneMask;
+
+ // Are all super-registers containing this SubRegIndex covered by their
+ // sub-registers?
+ bool AllSuperRegsCovered;
+
CodeGenSubRegIndex(Record *R, unsigned Enum);
+ CodeGenSubRegIndex(StringRef N, StringRef Nspace, unsigned Enum);
- const std::string &getName() const;
- std::string getNamespace() const;
+ const std::string &getName() const { return Name; }
+ const std::string &getNamespace() const { return Namespace; }
std::string getQualifiedName() const;
// Order CodeGenSubRegIndex pointers by EnumValue.
// Return a conflicting composite, or NULL
CodeGenSubRegIndex *addComposite(CodeGenSubRegIndex *A,
CodeGenSubRegIndex *B) {
+ assert(A && B);
std::pair<CompMap::iterator, bool> Ins =
Composed.insert(std::make_pair(A, B));
+ // Synthetic subreg indices that aren't contiguous (for instance ARM
+ // register tuples) don't have a bit range, so it's OK to let
+ // B->Offset == -1. For the other cases, accumulate the offset and set
+ // the size here. Only do so if there is no offset yet though.
+ if ((Offset != (uint16_t)-1 && A->Offset != (uint16_t)-1) &&
+ (B->Offset == (uint16_t)-1)) {
+ B->Offset = Offset + A->Offset;
+ B->Size = A->Size;
+ }
return (Ins.second || Ins.first->second == B) ? 0 : Ins.first->second;
}
// Update the composite maps of components specified in 'ComposedOf'.
void updateComponents(CodeGenRegBank&);
- // Clean out redundant composite mappings.
- void cleanComposites();
-
// Return the map of composites.
const CompMap &getComposites() const { return Composed; }
+ // Compute LaneMask from Composed. Return LaneMask.
+ unsigned computeLaneMask();
+
private:
CompMap Composed;
};
const std::string &getName() const;
- // Get a map of sub-registers computed lazily.
+ // Extract more information from TheDef. This is used to build an object
+ // graph after all CodeGenRegister objects have been created.
+ void buildObjectGraph(CodeGenRegBank&);
+
+ // Lazily compute a map of all sub-registers.
// This includes unique entries for all sub-sub-registers.
- const SubRegMap &getSubRegs(CodeGenRegBank&);
+ const SubRegMap &computeSubRegs(CodeGenRegBank&);
+
+ // Compute extra sub-registers by combining the existing sub-registers.
+ void computeSecondarySubRegs(CodeGenRegBank&);
+
+ // Add this as a super-register to all sub-registers after the sub-register
+ // graph has been built.
+ void computeSuperRegs(CodeGenRegBank&);
const SubRegMap &getSubRegs() const {
assert(SubRegsComplete && "Must precompute sub-registers");
void addSubRegsPreOrder(SetVector<const CodeGenRegister*> &OSet,
CodeGenRegBank&) const;
- // List of super-registers in topological order, small to large.
+ // Return the sub-register index naming Reg as a sub-register of this
+ // register. Returns NULL if Reg is not a sub-register.
+ CodeGenSubRegIndex *getSubRegIndex(const CodeGenRegister *Reg) const {
+ return SubReg2Idx.lookup(Reg);
+ }
+
typedef std::vector<const CodeGenRegister*> SuperRegList;
- // Get the list of super-registers.
- // This is only valid after computeDerivedInfo has visited all registers.
+ // Get the list of super-registers in topological order, small to large.
+ // This is valid after computeSubRegs visits all registers during RegBank
+ // construction.
const SuperRegList &getSuperRegs() const {
assert(SubRegsComplete && "Must precompute sub-registers");
return SuperRegs;
}
+ // Get the list of ad hoc aliases. The graph is symmetric, so the list
+ // contains all registers in 'Aliases', and all registers that mention this
+ // register in 'Aliases'.
+ ArrayRef<CodeGenRegister*> getExplicitAliases() const {
+ return ExplicitAliases;
+ }
+
+ // Get the topological signature of this register. This is a small integer
+ // less than RegBank.getNumTopoSigs(). Registers with the same TopoSig have
+ // identical sub-register structure. That is, they support the same set of
+ // sub-register indices mapping to the same kind of sub-registers
+ // (TopoSig-wise).
+ unsigned getTopoSig() const {
+ assert(SuperRegsComplete && "TopoSigs haven't been computed yet.");
+ return TopoSig;
+ }
+
+ // List of register units in ascending order.
+ typedef SmallVector<unsigned, 16> RegUnitList;
+
+ // How many entries in RegUnitList are native?
+ unsigned NumNativeRegUnits;
+
+ // Get the list of register units.
+ // This is only valid after computeSubRegs() completes.
+ const RegUnitList &getRegUnits() const { return RegUnits; }
+
+ // Get the native register units. This is a prefix of getRegUnits().
+ ArrayRef<unsigned> getNativeRegUnits() const {
+ return makeArrayRef(RegUnits).slice(0, NumNativeRegUnits);
+ }
+
+ // Inherit register units from subregisters.
+ // Return true if the RegUnits changed.
+ bool inheritRegUnits(CodeGenRegBank &RegBank);
+
+ // Adopt a register unit for pressure tracking.
+ // A unit is adopted iff its unit number is >= NumNativeRegUnits.
+ void adoptRegUnit(unsigned RUID) { RegUnits.push_back(RUID); }
+
+ // Get the sum of this register's register unit weights.
+ unsigned getWeight(const CodeGenRegBank &RegBank) const;
+
// Order CodeGenRegister pointers by EnumValue.
struct Less {
bool operator()(const CodeGenRegister *A,
private:
bool SubRegsComplete;
+ bool SuperRegsComplete;
+ unsigned TopoSig;
+
+ // The sub-registers explicit in the .td file form a tree.
+ SmallVector<CodeGenSubRegIndex*, 8> ExplicitSubRegIndices;
+ SmallVector<CodeGenRegister*, 8> ExplicitSubRegs;
+
+ // Explicit ad hoc aliases, symmetrized to form an undirected graph.
+ SmallVector<CodeGenRegister*, 8> ExplicitAliases;
+
+ // Super-registers where this is the first explicit sub-register.
+ SuperRegList LeadingSuperRegs;
+
SubRegMap SubRegs;
SuperRegList SuperRegs;
+ DenseMap<const CodeGenRegister*, CodeGenSubRegIndex*> SubReg2Idx;
+ RegUnitList RegUnits;
};
//
DenseMap<CodeGenSubRegIndex*,
SmallPtrSet<CodeGenRegisterClass*, 8> > SuperRegClasses;
+
+ // Bit vector of TopoSigs for the registers in this class. This will be
+ // very sparse on regular architectures.
+ BitVector TopoSigs;
+
public:
unsigned EnumValue;
std::string Namespace;
- std::vector<MVT::SimpleValueType> VTs;
+ SmallVector<MVT::SimpleValueType, 4> VTs;
unsigned SpillSize;
unsigned SpillAlignment;
int CopyCost;
bool Allocatable;
- // Map SubRegIndex -> RegisterClass
- DenseMap<Record*,Record*> SubRegClasses;
std::string AltOrderSelect;
// Return the Record that defined this class, or NULL if the class was
const std::string &getName() const { return Name; }
std::string getQualifiedName() const;
- const std::vector<MVT::SimpleValueType> &getValueTypes() const {return VTs;}
+ ArrayRef<MVT::SimpleValueType> getValueTypes() const {return VTs;}
unsigned getNumValueTypes() const { return VTs.size(); }
MVT::SimpleValueType getValueTypeNum(unsigned VTNum) const {
// getOrder(0).
const CodeGenRegister::Set &getMembers() const { return Members; }
+ // Get a bit vector of TopoSigs present in this register class.
+ const BitVector &getTopoSigs() const { return TopoSigs; }
+
+ // Populate a unique sorted list of units from a register set.
+ void buildRegUnitSet(std::vector<unsigned> &RegUnits) const;
+
CodeGenRegisterClass(CodeGenRegBank&, Record *R);
// A key representing the parts of a register class used for forming
};
// Create a non-user defined register class.
- CodeGenRegisterClass(StringRef Name, Key Props);
+ CodeGenRegisterClass(CodeGenRegBank&, StringRef Name, Key Props);
// Called by CodeGenRegBank::CodeGenRegBank().
static void computeSubClasses(CodeGenRegBank&);
};
+ // Register units are used to model interference and register pressure.
+ // Every register is assigned one or more register units such that two
+ // registers overlap if and only if they have a register unit in common.
+ //
+ // Normally, one register unit is created per leaf register. Non-leaf
+ // registers inherit the units of their sub-registers.
+ struct RegUnit {
+ // Weight assigned to this RegUnit for estimating register pressure.
+ // This is useful when equalizing weights in register classes with mixed
+ // register topologies.
+ unsigned Weight;
+
+ // Each native RegUnit corresponds to one or two root registers. The full
+ // set of registers containing this unit can be computed as the union of
+ // these two registers and their super-registers.
+ const CodeGenRegister *Roots[2];
+
+ // Index into RegClassUnitSets where we can find the list of UnitSets that
+ // contain this unit.
+ unsigned RegClassUnitSetsIdx;
+
+ RegUnit() : Weight(0), RegClassUnitSetsIdx(0) { Roots[0] = Roots[1] = 0; }
+
+ ArrayRef<const CodeGenRegister*> getRoots() const {
+ assert(!(Roots[1] && !Roots[0]) && "Invalid roots array");
+ return makeArrayRef(Roots, !!Roots[0] + !!Roots[1]);
+ }
+ };
+
+ // Each RegUnitSet is a sorted vector with a name.
+ struct RegUnitSet {
+ typedef std::vector<unsigned>::const_iterator iterator;
+
+ std::string Name;
+ std::vector<unsigned> Units;
+ };
+
+ // Base vector for identifying TopoSigs. The contents uniquely identify a
+ // TopoSig, only computeSuperRegs needs to know how.
+ typedef SmallVector<unsigned, 16> TopoSigId;
+
// CodeGenRegBank - Represent a target's registers and the relations between
// them.
class CodeGenRegBank {
- RecordKeeper &Records;
SetTheory Sets;
// SubRegIndices.
std::vector<CodeGenSubRegIndex*> SubRegIndices;
DenseMap<Record*, CodeGenSubRegIndex*> Def2SubRegIdx;
- unsigned NumNamedIndices;
+
+ CodeGenSubRegIndex *createSubRegIndex(StringRef Name, StringRef NameSpace);
+
+ typedef std::map<SmallVector<CodeGenSubRegIndex*, 8>,
+ CodeGenSubRegIndex*> ConcatIdxMap;
+ ConcatIdxMap ConcatIdx;
// Registers.
std::vector<CodeGenRegister*> Registers;
+ StringMap<CodeGenRegister*> RegistersByName;
DenseMap<Record*, CodeGenRegister*> Def2Reg;
+ unsigned NumNativeRegUnits;
+
+ std::map<TopoSigId, unsigned> TopoSigs;
+
+ // Includes native (0..NumNativeRegUnits-1) and adopted register units.
+ SmallVector<RegUnit, 8> RegUnits;
// Register classes.
std::vector<CodeGenRegisterClass*> RegClasses;
typedef std::map<CodeGenRegisterClass::Key, CodeGenRegisterClass*> RCKeyMap;
RCKeyMap Key2RC;
+ // Remember each unique set of register units. Initially, this contains a
+ // unique set for each register class. Simliar sets are coalesced with
+ // pruneUnitSets and new supersets are inferred during computeRegUnitSets.
+ std::vector<RegUnitSet> RegUnitSets;
+
+ // Map RegisterClass index to the index of the RegUnitSet that contains the
+ // class's units and any inferred RegUnit supersets.
+ //
+ // NOTE: This could grow beyond the number of register classes when we map
+ // register units to lists of unit sets. If the list of unit sets does not
+ // already exist for a register class, we create a new entry in this vector.
+ std::vector<std::vector<unsigned> > RegClassUnitSets;
+
// Add RC to *2RC maps.
void addToMaps(CodeGenRegisterClass*);
void inferMatchingSuperRegClass(CodeGenRegisterClass *RC,
unsigned FirstSubRegRC = 0);
+ // Iteratively prune unit sets.
+ void pruneUnitSets();
+
+ // Compute a weight for each register unit created during getSubRegs.
+ void computeRegUnitWeights();
+
+ // Create a RegUnitSet for each RegClass and infer superclasses.
+ void computeRegUnitSets();
+
// Populate the Composite map from sub-register relationships.
void computeComposites();
+ // Compute a lane mask for each sub-register index.
+ void computeSubRegIndexLaneMasks();
+
public:
CodeGenRegBank(RecordKeeper&);
// in the .td files. The rest are synthesized such that all sub-registers
// have a unique name.
ArrayRef<CodeGenSubRegIndex*> getSubRegIndices() { return SubRegIndices; }
- unsigned getNumNamedIndices() { return NumNamedIndices; }
// Find a SubRegIndex form its Record def.
CodeGenSubRegIndex *getSubRegIdx(Record*);
CodeGenSubRegIndex *getCompositeSubRegIndex(CodeGenSubRegIndex *A,
CodeGenSubRegIndex *B);
+ // Find or create a sub-register index representing the concatenation of
+ // non-overlapping sibling indices.
+ CodeGenSubRegIndex *
+ getConcatSubRegIndex(const SmallVector<CodeGenSubRegIndex*, 8>&);
+
+ void
+ addConcatSubRegIndex(const SmallVector<CodeGenSubRegIndex*, 8> &Parts,
+ CodeGenSubRegIndex *Idx) {
+ ConcatIdx.insert(std::make_pair(Parts, Idx));
+ }
+
const std::vector<CodeGenRegister*> &getRegisters() { return Registers; }
+ const StringMap<CodeGenRegister*> &getRegistersByName() {
+ return RegistersByName;
+ }
// Find a register from its Record def.
CodeGenRegister *getReg(Record*);
+ // Get a Register's index into the Registers array.
+ unsigned getRegIndex(const CodeGenRegister *Reg) const {
+ return Reg->EnumValue - 1;
+ }
+
+ // Return the number of allocated TopoSigs. The first TopoSig representing
+ // leaf registers is allocated number 0.
+ unsigned getNumTopoSigs() const {
+ return TopoSigs.size();
+ }
+
+ // Find or create a TopoSig for the given TopoSigId.
+ // This function is only for use by CodeGenRegister::computeSuperRegs().
+ // Others should simply use Reg->getTopoSig().
+ unsigned getTopoSig(const TopoSigId &Id) {
+ return TopoSigs.insert(std::make_pair(Id, TopoSigs.size())).first->second;
+ }
+
+ // Create a native register unit that is associated with one or two root
+ // registers.
+ unsigned newRegUnit(CodeGenRegister *R0, CodeGenRegister *R1 = 0) {
+ RegUnits.resize(RegUnits.size() + 1);
+ RegUnits.back().Roots[0] = R0;
+ RegUnits.back().Roots[1] = R1;
+ return RegUnits.size() - 1;
+ }
+
+ // Create a new non-native register unit that can be adopted by a register
+ // to increase its pressure. Note that NumNativeRegUnits is not increased.
+ unsigned newRegUnit(unsigned Weight) {
+ RegUnits.resize(RegUnits.size() + 1);
+ RegUnits.back().Weight = Weight;
+ return RegUnits.size() - 1;
+ }
+
+ // Native units are the singular unit of a leaf register. Register aliasing
+ // is completely characterized by native units. Adopted units exist to give
+ // register additional weight but don't affect aliasing.
+ bool isNativeUnit(unsigned RUID) {
+ return RUID < NumNativeRegUnits;
+ }
+
+ unsigned getNumNativeRegUnits() const {
+ return NumNativeRegUnits;
+ }
+
+ RegUnit &getRegUnit(unsigned RUID) { return RegUnits[RUID]; }
+ const RegUnit &getRegUnit(unsigned RUID) const { return RegUnits[RUID]; }
+
ArrayRef<CodeGenRegisterClass*> getRegClasses() const {
return RegClasses;
}
/// return the superclass. Otherwise return null.
const CodeGenRegisterClass* getRegClassForRegister(Record *R);
+ // Get the sum of unit weights.
+ unsigned getRegUnitSetWeight(const std::vector<unsigned> &Units) const {
+ unsigned Weight = 0;
+ for (std::vector<unsigned>::const_iterator
+ I = Units.begin(), E = Units.end(); I != E; ++I)
+ Weight += getRegUnit(*I).Weight;
+ return Weight;
+ }
+
+ // Increase a RegUnitWeight.
+ void increaseRegUnitWeight(unsigned RUID, unsigned Inc) {
+ getRegUnit(RUID).Weight += Inc;
+ }
+
+ // Get the number of register pressure dimensions.
+ unsigned getNumRegPressureSets() const { return RegUnitSets.size(); }
+
+ // Get a set of register unit IDs for a given dimension of pressure.
+ RegUnitSet getRegPressureSet(unsigned Idx) const {
+ return RegUnitSets[Idx];
+ }
+
+ // The number of pressure set lists may be larget than the number of
+ // register classes if some register units appeared in a list of sets that
+ // did not correspond to an existing register class.
+ unsigned getNumRegClassPressureSetLists() const {
+ return RegClassUnitSets.size();
+ }
+
+ // Get a list of pressure set IDs for a register class. Liveness of a
+ // register in this class impacts each pressure set in this list by the
+ // weight of the register. An exact solution requires all registers in a
+ // class to have the same class, but it is not strictly guaranteed.
+ ArrayRef<unsigned> getRCPressureSetIDs(unsigned RCIdx) const {
+ return RegClassUnitSets[RCIdx];
+ }
+
// Computed derived records such as missing sub-register indices.
void computeDerivedInfo();
- // Compute full overlap sets for every register. These sets include the
- // rarely used aliases that are neither sub nor super-registers.
- //
- // Map[R1].count(R2) is reflexive and symmetric, but not transitive.
- //
- // If R1 is a sub-register of R2, Map[R1] is a subset of Map[R2].
- void computeOverlaps(std::map<const CodeGenRegister*,
- CodeGenRegister::Set> &Map);
-
// Compute the set of registers completely covered by the registers in Regs.
// The returned BitVector will have a bit set for each register in Regs,
// all sub-registers, and all super-registers that are covered by the
// This is used to compute the mask of call-preserved registers from a list
// of callee-saves.
BitVector computeCoveredRegisters(ArrayRef<Record*> Regs);
+
+ // Bit mask of lanes that cover their registers. A sub-register index whose
+ // LaneMask is contained in CoveringLanes will be completely covered by
+ // another sub-register with the same or larger lane mask.
+ unsigned CoveringLanes;
};
}