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+//===- CodeGenRegisters.h - Register and RegisterClass Info -----*- 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 structures to encapsulate information gleaned from the
+// target register and register class definitions.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef CODEGEN_REGISTERS_H
+#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/Support/ErrorHandling.h"
+#include <cstdlib>
+#include <map>
+#include <string>
+#include <set>
+#include <vector>
+
+namespace llvm {
+ class CodeGenRegBank;
+
+ /// CodeGenSubRegIndex - Represents a sub-register index.
+ class CodeGenSubRegIndex {
+ Record *const TheDef;
+ const unsigned EnumValue;
+
+ public:
+ CodeGenSubRegIndex(Record *R, unsigned Enum);
+
+ const std::string &getName() const;
+ std::string getNamespace() const;
+ std::string getQualifiedName() const;
+
+ // Order CodeGenSubRegIndex pointers by EnumValue.
+ struct Less {
+ bool operator()(const CodeGenSubRegIndex *A,
+ const CodeGenSubRegIndex *B) const {
+ assert(A && B);
+ return A->EnumValue < B->EnumValue;
+ }
+ };
+
+ // Map of composite subreg indices.
+ typedef std::map<CodeGenSubRegIndex*, CodeGenSubRegIndex*, Less> CompMap;
+
+ // Returns the subreg index that results from composing this with Idx.
+ // Returns NULL if this and Idx don't compose.
+ CodeGenSubRegIndex *compose(CodeGenSubRegIndex *Idx) const {
+ CompMap::const_iterator I = Composed.find(Idx);
+ return I == Composed.end() ? 0 : I->second;
+ }
+
+ // Add a composite subreg index: this+A = B.
+ // Return a conflicting composite, or NULL
+ CodeGenSubRegIndex *addComposite(CodeGenSubRegIndex *A,
+ CodeGenSubRegIndex *B) {
+ std::pair<CompMap::iterator, bool> Ins =
+ Composed.insert(std::make_pair(A, B));
+ 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; }
+
+ private:
+ CompMap Composed;
+ };
+
+ /// CodeGenRegister - Represents a register definition.
+ struct CodeGenRegister {
+ Record *TheDef;
+ unsigned EnumValue;
+ unsigned CostPerUse;
+ bool CoveredBySubRegs;
+
+ // Map SubRegIndex -> Register.
+ typedef std::map<CodeGenSubRegIndex*, CodeGenRegister*,
+ CodeGenSubRegIndex::Less> SubRegMap;
+
+ CodeGenRegister(Record *R, unsigned Enum);
+
+ const std::string &getName() const;
+
+ // Get a map of sub-registers computed lazily.
+ // This includes unique entries for all sub-sub-registers.
+ const SubRegMap &getSubRegs(CodeGenRegBank&);
+
+ const SubRegMap &getSubRegs() const {
+ assert(SubRegsComplete && "Must precompute sub-registers");
+ return SubRegs;
+ }
+
+ // Add sub-registers to OSet following a pre-order defined by the .td file.
+ void addSubRegsPreOrder(SetVector<const CodeGenRegister*> &OSet,
+ CodeGenRegBank&) const;
+
+ // List of super-registers in topological order, small to large.
+ typedef std::vector<const CodeGenRegister*> SuperRegList;
+
+ // Get the list of super-registers. This is valid after getSubReg
+ // visits all registers during RegBank construction.
+ const SuperRegList &getSuperRegs() const {
+ assert(SubRegsComplete && "Must precompute sub-registers");
+ return SuperRegs;
+ }
+
+ // List of register units in ascending order.
+ typedef SmallVector<unsigned, 16> RegUnitList;
+
+ // Get the list of register units.
+ // This is only valid after getSubRegs() completes.
+ const RegUnitList &getRegUnits() const { return RegUnits; }
+
+ // 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,
+ const CodeGenRegister *B) const {
+ assert(A && B);
+ return A->EnumValue < B->EnumValue;
+ }
+ };
+
+ // Canonically ordered set.
+ typedef std::set<const CodeGenRegister*, Less> Set;
+
+ private:
+ bool SubRegsComplete;
+ SubRegMap SubRegs;
+ SuperRegList SuperRegs;
+ RegUnitList RegUnits;
+ };
+
+
+ class CodeGenRegisterClass {
+ CodeGenRegister::Set Members;
+ // Allocation orders. Order[0] always contains all registers in Members.
+ std::vector<SmallVector<Record*, 16> > Orders;
+ // Bit mask of sub-classes including this, indexed by their EnumValue.
+ BitVector SubClasses;
+ // List of super-classes, topologocally ordered to have the larger classes
+ // first. This is the same as sorting by EnumValue.
+ SmallVector<CodeGenRegisterClass*, 4> SuperClasses;
+ Record *TheDef;
+ std::string Name;
+
+ // For a synthesized class, inherit missing properties from the nearest
+ // super-class.
+ void inheritProperties(CodeGenRegBank&);
+
+ // Map SubRegIndex -> sub-class. This is the largest sub-class where all
+ // registers have a SubRegIndex sub-register.
+ DenseMap<CodeGenSubRegIndex*, CodeGenRegisterClass*> SubClassWithSubReg;
+
+ // Map SubRegIndex -> set of super-reg classes. This is all register
+ // classes SuperRC such that:
+ //
+ // R:SubRegIndex in this RC for all R in SuperRC.
+ //
+ DenseMap<CodeGenSubRegIndex*,
+ SmallPtrSet<CodeGenRegisterClass*, 8> > SuperRegClasses;
+
+ public:
+ unsigned EnumValue;
+ std::string Namespace;
+ std::vector<MVT::SimpleValueType> 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
+ // created by TableGen.
+ Record *getDef() const { return TheDef; }
+
+ const std::string &getName() const { return Name; }
+ std::string getQualifiedName() const;
+ const std::vector<MVT::SimpleValueType> &getValueTypes() const {return VTs;}
+ unsigned getNumValueTypes() const { return VTs.size(); }
+
+ MVT::SimpleValueType getValueTypeNum(unsigned VTNum) const {
+ if (VTNum < VTs.size())
+ return VTs[VTNum];
+ llvm_unreachable("VTNum greater than number of ValueTypes in RegClass!");
+ }
+
+ // Return true if this this class contains the register.
+ bool contains(const CodeGenRegister*) const;
+
+ // Returns true if RC is a subclass.
+ // RC is a sub-class of this class if it is a valid replacement for any
+ // instruction operand where a register of this classis required. It must
+ // satisfy these conditions:
+ //
+ // 1. All RC registers are also in this.
+ // 2. The RC spill size must not be smaller than our spill size.
+ // 3. RC spill alignment must be compatible with ours.
+ //
+ bool hasSubClass(const CodeGenRegisterClass *RC) const {
+ return SubClasses.test(RC->EnumValue);
+ }
+
+ // getSubClassWithSubReg - Returns the largest sub-class where all
+ // registers have a SubIdx sub-register.
+ CodeGenRegisterClass*
+ getSubClassWithSubReg(CodeGenSubRegIndex *SubIdx) const {
+ return SubClassWithSubReg.lookup(SubIdx);
+ }
+
+ void setSubClassWithSubReg(CodeGenSubRegIndex *SubIdx,
+ CodeGenRegisterClass *SubRC) {
+ SubClassWithSubReg[SubIdx] = SubRC;
+ }
+
+ // getSuperRegClasses - Returns a bit vector of all register classes
+ // containing only SubIdx super-registers of this class.
+ void getSuperRegClasses(CodeGenSubRegIndex *SubIdx, BitVector &Out) const;
+
+ // addSuperRegClass - Add a class containing only SudIdx super-registers.
+ void addSuperRegClass(CodeGenSubRegIndex *SubIdx,
+ CodeGenRegisterClass *SuperRC) {
+ SuperRegClasses[SubIdx].insert(SuperRC);
+ }
+
+ // getSubClasses - Returns a constant BitVector of subclasses indexed by
+ // EnumValue.
+ // The SubClasses vector includs an entry for this class.
+ const BitVector &getSubClasses() const { return SubClasses; }
+
+ // getSuperClasses - Returns a list of super classes ordered by EnumValue.
+ // The array does not include an entry for this class.
+ ArrayRef<CodeGenRegisterClass*> getSuperClasses() const {
+ return SuperClasses;
+ }
+
+ // Returns an ordered list of class members.
+ // The order of registers is the same as in the .td file.
+ // No = 0 is the default allocation order, No = 1 is the first alternative.
+ ArrayRef<Record*> getOrder(unsigned No = 0) const {
+ return Orders[No];
+ }
+
+ // Return the total number of allocation orders available.
+ unsigned getNumOrders() const { return Orders.size(); }
+
+ // Get the set of registers. This set contains the same registers as
+ // getOrder(0).
+ const CodeGenRegister::Set &getMembers() const { return Members; }
+
+ // 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
+ // sub-classes. Note the ordering provided by this key is not the same as
+ // the topological order used for the EnumValues.
+ struct Key {
+ const CodeGenRegister::Set *Members;
+ unsigned SpillSize;
+ unsigned SpillAlignment;
+
+ Key(const Key &O)
+ : Members(O.Members),
+ SpillSize(O.SpillSize),
+ SpillAlignment(O.SpillAlignment) {}
+
+ Key(const CodeGenRegister::Set *M, unsigned S = 0, unsigned A = 0)
+ : Members(M), SpillSize(S), SpillAlignment(A) {}
+
+ Key(const CodeGenRegisterClass &RC)
+ : Members(&RC.getMembers()),
+ SpillSize(RC.SpillSize),
+ SpillAlignment(RC.SpillAlignment) {}
+
+ // Lexicographical order of (Members, SpillSize, SpillAlignment).
+ bool operator<(const Key&) const;
+ };
+
+ // Create a non-user defined register class.
+ CodeGenRegisterClass(StringRef Name, Key Props);
+
+ // Called by CodeGenRegBank::CodeGenRegBank().
+ static void computeSubClasses(CodeGenRegBank&);
+ };
+
+ // 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;
+ };
+
+ // 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;
+
+ // Registers.
+ std::vector<CodeGenRegister*> Registers;
+ DenseMap<Record*, CodeGenRegister*> Def2Reg;
+ unsigned NumNativeRegUnits;
+ unsigned NumRegUnits; // # native + adopted register units.
+
+ // Map each register unit to a weight (for register pressure).
+ // Includes native and adopted register units.
+ std::vector<unsigned> RegUnitWeights;
+
+ // Register classes.
+ std::vector<CodeGenRegisterClass*> RegClasses;
+ DenseMap<Record*, CodeGenRegisterClass*> Def2RC;
+ 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.
+ std::vector<std::vector<unsigned> > RegClassUnitSets;
+
+ // Add RC to *2RC maps.
+ void addToMaps(CodeGenRegisterClass*);
+
+ // Create a synthetic sub-class if it is missing.
+ CodeGenRegisterClass *getOrCreateSubClass(const CodeGenRegisterClass *RC,
+ const CodeGenRegister::Set *Membs,
+ StringRef Name);
+
+ // Infer missing register classes.
+ void computeInferredRegisterClasses();
+ void inferCommonSubClass(CodeGenRegisterClass *RC);
+ void inferSubClassWithSubReg(CodeGenRegisterClass *RC);
+ 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();
+
+ public:
+ CodeGenRegBank(RecordKeeper&);
+
+ SetTheory &getSets() { return Sets; }
+
+ // Sub-register indices. The first NumNamedIndices are defined by the user
+ // 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*);
+
+ // Find or create a sub-register index representing the A+B composition.
+ CodeGenSubRegIndex *getCompositeSubRegIndex(CodeGenSubRegIndex *A,
+ CodeGenSubRegIndex *B);
+
+ const std::vector<CodeGenRegister*> &getRegisters() { return Registers; }
+
+ // 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;
+ }
+
+ // 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) {
+ if (!RegUnitWeights.empty()) {
+ assert(Weight && "should only add allocatable units");
+ RegUnitWeights.resize(NumRegUnits+1);
+ RegUnitWeights[NumRegUnits] = Weight;
+ }
+ return NumRegUnits++;
+ }
+
+ // 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;
+ }
+
+ ArrayRef<CodeGenRegisterClass*> getRegClasses() const {
+ return RegClasses;
+ }
+
+ // Find a register class from its def.
+ CodeGenRegisterClass *getRegClass(Record*);
+
+ /// getRegisterClassForRegister - Find the register class that contains the
+ /// specified physical register. If the register is not in a register
+ /// class, return null. If the register is in multiple classes, and the
+ /// classes have a superset-subset relationship and the same set of types,
+ /// return the superclass. Otherwise return null.
+ const CodeGenRegisterClass* getRegClassForRegister(Record *R);
+
+ // Get a register unit's weight. Zero for unallocatable registers.
+ unsigned getRegUnitWeight(unsigned RUID) const {
+ return RegUnitWeights[RUID];
+ }
+
+ // 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 += getRegUnitWeight(*I);
+ return Weight;
+ }
+
+ // Increase a RegUnitWeight.
+ void increaseRegUnitWeight(unsigned RUID, unsigned Inc) {
+ RegUnitWeights[RUID] += 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];
+ }
+
+ // 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
+ // registers in Regs.
+ //
+ // This is used to compute the mask of call-preserved registers from a list
+ // of callee-saves.
+ BitVector computeCoveredRegisters(ArrayRef<Record*> Regs);
+ };
+}
+
+#endif
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