virtual const RegClassWeight &getRegClassWeight(
const TargetRegisterClass *RC) const = 0;
+ /// Get the weight in units of pressure for this register unit.
+ virtual unsigned getRegUnitWeight(unsigned RegUnit) const = 0;
+
/// Get the number of dimensions of register pressure.
virtual unsigned getNumRegPressureSets() const = 0;
virtual const int *getRegClassPressureSets(
const TargetRegisterClass *RC) const = 0;
+ /// Get the dimensions of register pressure impacted by this register unit.
+ /// Returns a -1 terminated array of pressure set IDs.
+ virtual const int *getRegUnitPressureSets(unsigned RegUnit) const = 0;
+
/// Get a list of 'hint' registers that the register allocator should try
/// first when allocating a physical register for the virtual register
/// VirtReg. These registers are effectively moved to the front of the
const MachineFunction &MF,
const VirtRegMap *VRM = 0) const;
+ /// getRawAllocationOrder - Returns the register allocation order for a
+ /// specified register class with a target-dependent hint. The returned list
+ /// may contain reserved registers that cannot be allocated.
+ ///
+ /// Register allocators need only call this function to resolve
+ /// target-dependent hints, but it should work without hinting as well.
+ virtual ArrayRef<MCPhysReg>
+ getRawAllocationOrder(const TargetRegisterClass *RC,
+ unsigned HintType, unsigned HintReg,
+ const MachineFunction &MF) const {
+ return RC->getRawAllocationOrder(MF);
+ }
+
+ /// ResolveRegAllocHint - Resolves the specified register allocation hint
+ /// to a physical register. Returns the physical register if it is successful.
+ virtual unsigned ResolveRegAllocHint(unsigned Type, unsigned Reg,
+ const MachineFunction &MF) const {
+ if (Type == 0 && Reg && isPhysicalRegister(Reg))
+ return Reg;
+ return 0;
+ }
+
/// avoidWriteAfterWrite - Return true if the register allocator should avoid
/// writing a register from RC in two consecutive instructions.
/// This can avoid pipeline stalls on certain architectures.
}
assert(!RegClassUnitSets[RCIdx].empty() && "missing unit set for regclass");
}
+
+ // For each register unit, ensure that we have the list of UnitSets that
+ // contain the unit. Normally, this matches an existing list of UnitSets for a
+ // register class. If not, we create a new entry in RegClassUnitSets as a
+ // "fake" register class.
+ for (unsigned UnitIdx = 0, UnitEnd = NumNativeRegUnits;
+ UnitIdx < UnitEnd; ++UnitIdx) {
+ std::vector<unsigned> RUSets;
+ for (unsigned i = 0, e = RegUnitSets.size(); i != e; ++i) {
+ RegUnitSet &RUSet = RegUnitSets[i];
+ if (std::find(RUSet.Units.begin(), RUSet.Units.end(), UnitIdx)
+ == RUSet.Units.end())
+ continue;
+ RUSets.push_back(i);
+ }
+ unsigned RCUnitSetsIdx = 0;
+ for (unsigned e = RegClassUnitSets.size();
+ RCUnitSetsIdx != e; ++RCUnitSetsIdx) {
+ if (RegClassUnitSets[RCUnitSetsIdx] == RUSets) {
+ break;
+ }
+ }
+ RegUnits[UnitIdx].RegClassUnitSetsIdx = RCUnitSetsIdx;
+ if (RCUnitSetsIdx == RegClassUnitSets.size()) {
+ // Create a new list of UnitSets as a "fake" register class.
+ RegClassUnitSets.resize(RCUnitSetsIdx + 1);
+ RegClassUnitSets[RCUnitSetsIdx].swap(RUSets);
+ }
+ }
}
void CodeGenRegBank::computeDerivedInfo() {
// these two registers and their super-registers.
const CodeGenRegister *Roots[2];
- RegUnit() : Weight(0) { Roots[0] = Roots[1] = 0; }
+ // 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");
// 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.
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
<< " return RCWeightTable[RC->getID()];\n"
<< "}\n\n";
+ // Reasonable targets (not ARMv7) have unit weight for all units, so don't
+ // bother generating a table.
+ bool RegUnitsHaveUnitWeight = true;
+ for (unsigned UnitIdx = 0, UnitEnd = RegBank.getNumNativeRegUnits();
+ UnitIdx < UnitEnd; ++UnitIdx) {
+ if (RegBank.getRegUnit(UnitIdx).Weight > 1)
+ RegUnitsHaveUnitWeight = false;
+ }
+ OS << "/// Get the weight in units of pressure for this register unit.\n"
+ << "unsigned " << ClassName << "::\n"
+ << "getRegUnitWeight(unsigned RegUnit) const {\n";
+ if (!RegUnitsHaveUnitWeight) {
+ OS << " static const uint8_t RUWeightTable[] = {\n ";
+ for (unsigned UnitIdx = 0, UnitEnd = RegBank.getNumNativeRegUnits();
+ UnitIdx < UnitEnd; ++UnitIdx) {
+ const RegUnit &RU = RegBank.getRegUnit(UnitIdx);
+ assert(RU.Weight < 256 && "RegUnit too heavy");
+ OS << RU.Weight << ", ";
+ }
+ OS << "0 };\n"
+ << " return RUWeightTable[RegUnit];\n";
+ }
+ else {
+ OS << " // All register units have unit weight.\n"
+ << " return 1;\n";
+ }
+ OS << "}\n\n";
+
OS << "\n"
<< "// Get the number of dimensions of register pressure.\n"
<< "unsigned " << ClassName << "::getNumRegPressureSets() const {\n"
<< " return PressureLimitTable[Idx];\n"
<< "}\n\n";
- OS << "/// Get the dimensions of register pressure "
- << "impacted by this register class.\n"
- << "/// Returns a -1 terminated array of pressure set IDs\n"
- << "const int* " << ClassName << "::\n"
- << "getRegClassPressureSets(const TargetRegisterClass *RC) const {\n"
- << " static const int RCSetsTable[] = {\n ";
- std::vector<unsigned> RCSetStarts(NumRCs);
- for (unsigned i = 0, StartIdx = 0, e = NumRCs; i != e; ++i) {
+ // This table may be larger than NumRCs if some register units needed a list
+ // of unit sets that did not correspond to a register class.
+ unsigned NumRCUnitSets = RegBank.getNumRegClassPressureSetLists();
+ OS << "/// Table of pressure sets per register class or unit.\n"
+ << "static const int RCSetsTable[] = {\n ";
+ std::vector<unsigned> RCSetStarts(NumRCUnitSets);
+ for (unsigned i = 0, StartIdx = 0, e = NumRCUnitSets; i != e; ++i) {
RCSetStarts[i] = StartIdx;
ArrayRef<unsigned> PSetIDs = RegBank.getRCPressureSetIDs(i);
for (ArrayRef<unsigned>::iterator PSetI = PSetIDs.begin(),
OS << *PSetI << ", ";
++StartIdx;
}
- OS << "-1, \t// " << RegBank.getRegClasses()[i]->getName() << "\n ";
+ OS << "-1, \t// #" << RCSetStarts[i] << " ";
+ if (i < NumRCs)
+ OS << RegBank.getRegClasses()[i]->getName();
+ else {
+ OS << "inferred";
+ for (ArrayRef<unsigned>::iterator PSetI = PSetIDs.begin(),
+ PSetE = PSetIDs.end(); PSetI != PSetE; ++PSetI) {
+ OS << "~" << RegBank.getRegPressureSet(*PSetI).Name;
+ }
+ }
+ OS << "\n ";
++StartIdx;
}
- OS << "-1 };\n";
+ OS << "-1 };\n\n";
+
+ OS << "/// Get the dimensions of register pressure impacted by this "
+ << "register class.\n"
+ << "/// Returns a -1 terminated array of pressure set IDs\n"
+ << "const int* " << ClassName << "::\n"
+ << "getRegClassPressureSets(const TargetRegisterClass *RC) const {\n";
OS << " static const unsigned RCSetStartTable[] = {\n ";
for (unsigned i = 0, e = NumRCs; i != e; ++i) {
OS << RCSetStarts[i] << ",";
<< " unsigned SetListStart = RCSetStartTable[RC->getID()];\n"
<< " return &RCSetsTable[SetListStart];\n"
<< "}\n\n";
+
+ OS << "/// Get the dimensions of register pressure impacted by this "
+ << "register unit.\n"
+ << "/// Returns a -1 terminated array of pressure set IDs\n"
+ << "const int* " << ClassName << "::\n"
+ << "getRegUnitPressureSets(unsigned RegUnit) const {\n";
+ OS << " static const unsigned RUSetStartTable[] = {\n ";
+ for (unsigned UnitIdx = 0, UnitEnd = RegBank.getNumNativeRegUnits();
+ UnitIdx < UnitEnd; ++UnitIdx) {
+ OS << RCSetStarts[RegBank.getRegUnit(UnitIdx).RegClassUnitSetsIdx] << ",";
+ }
+ OS << "0 };\n"
+ << " unsigned SetListStart = RUSetStartTable[RegUnit];\n"
+ << " return &RCSetsTable[SetListStart];\n"
+ << "}\n\n";
}
void
}
OS << " virtual const RegClassWeight &getRegClassWeight("
<< "const TargetRegisterClass *RC) const;\n"
+ << " virtual unsigned getRegUnitWeight(unsigned RegUnit) const;\n"
<< " virtual unsigned getNumRegPressureSets() const;\n"
<< " virtual const char *getRegPressureSetName(unsigned Idx) const;\n"
<< " virtual unsigned getRegPressureSetLimit(unsigned Idx) const;\n"
<< " virtual const int *getRegClassPressureSets("
<< "const TargetRegisterClass *RC) const;\n"
+ << " virtual const int *getRegUnitPressureSets(unsigned RegUnit) const;\n"
<< "};\n\n";
ArrayRef<CodeGenRegisterClass*> RegisterClasses = RegBank.getRegClasses();