1 //===- CodeGenRegisters.cpp - Register and RegisterClass Info -------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file defines structures to encapsulate information gleaned from the
11 // target register and register class definitions.
13 //===----------------------------------------------------------------------===//
15 #include "CodeGenRegisters.h"
16 #include "CodeGenTarget.h"
17 #include "llvm/TableGen/Error.h"
18 #include "llvm/ADT/SmallVector.h"
19 #include "llvm/ADT/STLExtras.h"
20 #include "llvm/ADT/StringExtras.h"
24 //===----------------------------------------------------------------------===//
26 //===----------------------------------------------------------------------===//
28 CodeGenSubRegIndex::CodeGenSubRegIndex(Record *R, unsigned Enum)
33 std::string CodeGenSubRegIndex::getNamespace() const {
34 if (TheDef->getValue("Namespace"))
35 return TheDef->getValueAsString("Namespace");
40 const std::string &CodeGenSubRegIndex::getName() const {
41 return TheDef->getName();
44 std::string CodeGenSubRegIndex::getQualifiedName() const {
45 std::string N = getNamespace();
52 void CodeGenSubRegIndex::updateComponents(CodeGenRegBank &RegBank) {
53 std::vector<Record*> Comps = TheDef->getValueAsListOfDefs("ComposedOf");
56 if (Comps.size() != 2)
57 throw TGError(TheDef->getLoc(), "ComposedOf must have exactly two entries");
58 CodeGenSubRegIndex *A = RegBank.getSubRegIdx(Comps[0]);
59 CodeGenSubRegIndex *B = RegBank.getSubRegIdx(Comps[1]);
60 CodeGenSubRegIndex *X = A->addComposite(B, this);
62 throw TGError(TheDef->getLoc(), "Ambiguous ComposedOf entries");
65 void CodeGenSubRegIndex::cleanComposites() {
66 // Clean out redundant mappings of the form this+X -> X.
67 for (CompMap::iterator i = Composed.begin(), e = Composed.end(); i != e;) {
68 CompMap::iterator j = i;
70 if (j->first == j->second)
75 //===----------------------------------------------------------------------===//
77 //===----------------------------------------------------------------------===//
79 CodeGenRegister::CodeGenRegister(Record *R, unsigned Enum)
82 CostPerUse(R->getValueAsInt("CostPerUse")),
83 CoveredBySubRegs(R->getValueAsBit("CoveredBySubRegs")),
84 SubRegsComplete(false)
87 const std::string &CodeGenRegister::getName() const {
88 return TheDef->getName();
91 // Merge two RegUnitLists maintining the order and removing duplicates.
92 // Overwrites MergedRU in the process.
93 static void mergeRegUnits(CodeGenRegister::RegUnitList &MergedRU,
94 const CodeGenRegister::RegUnitList &RRU)
96 CodeGenRegister::RegUnitList LRU = MergedRU;
98 for (CodeGenRegister::RegUnitList::const_iterator
99 RI = RRU.begin(), RE = RRU.end(), LI = LRU.begin(), LE = LRU.end();
100 RI != RE || LI != LE;) {
102 CodeGenRegister::RegUnitList::const_iterator &NextI =
103 (RI != RE && (LI == LE || *RI < *LI)) ? RI : LI;
105 if (MergedRU.empty() || *NextI != MergedRU.back())
106 MergedRU.push_back(*NextI);
111 const CodeGenRegister::SubRegMap &
112 CodeGenRegister::getSubRegs(CodeGenRegBank &RegBank) {
113 // Only compute this map once.
116 SubRegsComplete = true;
118 std::vector<Record*> SubList = TheDef->getValueAsListOfDefs("SubRegs");
119 std::vector<Record*> IdxList = TheDef->getValueAsListOfDefs("SubRegIndices");
120 if (SubList.size() != IdxList.size())
121 throw TGError(TheDef->getLoc(), "Register " + getName() +
122 " SubRegIndices doesn't match SubRegs");
124 // First insert the direct subregs and make sure they are fully indexed.
125 SmallVector<CodeGenSubRegIndex*, 8> Indices;
126 for (unsigned i = 0, e = SubList.size(); i != e; ++i) {
127 CodeGenRegister *SR = RegBank.getReg(SubList[i]);
128 CodeGenSubRegIndex *Idx = RegBank.getSubRegIdx(IdxList[i]);
129 Indices.push_back(Idx);
130 if (!SubRegs.insert(std::make_pair(Idx, SR)).second)
131 throw TGError(TheDef->getLoc(), "SubRegIndex " + Idx->getName() +
132 " appears twice in Register " + getName());
135 // Keep track of inherited subregs and how they can be reached.
136 SmallPtrSet<CodeGenRegister*, 8> Orphans;
138 // Clone inherited subregs and place duplicate entries in Orphans.
139 // Here the order is important - earlier subregs take precedence.
140 for (unsigned i = 0, e = SubList.size(); i != e; ++i) {
141 CodeGenRegister *SR = RegBank.getReg(SubList[i]);
142 const SubRegMap &Map = SR->getSubRegs(RegBank);
144 // Add this as a super-register of SR now all sub-registers are in the list.
145 // This creates a topological ordering, the exact order depends on the
146 // order getSubRegs is called on all registers.
147 SR->SuperRegs.push_back(this);
149 for (SubRegMap::const_iterator SI = Map.begin(), SE = Map.end(); SI != SE;
151 if (!SubRegs.insert(*SI).second)
152 Orphans.insert(SI->second);
154 // Noop sub-register indexes are possible, so avoid duplicates.
155 if (SI->second != SR)
156 SI->second->SuperRegs.push_back(this);
160 // Expand any composed subreg indices.
161 // If dsub_2 has ComposedOf = [qsub_1, dsub_0], and this register has a
162 // qsub_1 subreg, add a dsub_2 subreg. Keep growing Indices and process
163 // expanded subreg indices recursively.
164 for (unsigned i = 0; i != Indices.size(); ++i) {
165 CodeGenSubRegIndex *Idx = Indices[i];
166 const CodeGenSubRegIndex::CompMap &Comps = Idx->getComposites();
167 CodeGenRegister *SR = SubRegs[Idx];
168 const SubRegMap &Map = SR->getSubRegs(RegBank);
170 // Look at the possible compositions of Idx.
171 // They may not all be supported by SR.
172 for (CodeGenSubRegIndex::CompMap::const_iterator I = Comps.begin(),
173 E = Comps.end(); I != E; ++I) {
174 SubRegMap::const_iterator SRI = Map.find(I->first);
175 if (SRI == Map.end())
176 continue; // Idx + I->first doesn't exist in SR.
177 // Add I->second as a name for the subreg SRI->second, assuming it is
178 // orphaned, and the name isn't already used for something else.
179 if (SubRegs.count(I->second) || !Orphans.erase(SRI->second))
181 // We found a new name for the orphaned sub-register.
182 SubRegs.insert(std::make_pair(I->second, SRI->second));
183 Indices.push_back(I->second);
187 // Process the composites.
188 ListInit *Comps = TheDef->getValueAsListInit("CompositeIndices");
189 for (unsigned i = 0, e = Comps->size(); i != e; ++i) {
190 DagInit *Pat = dynamic_cast<DagInit*>(Comps->getElement(i));
192 throw TGError(TheDef->getLoc(), "Invalid dag '" +
193 Comps->getElement(i)->getAsString() +
194 "' in CompositeIndices");
195 DefInit *BaseIdxInit = dynamic_cast<DefInit*>(Pat->getOperator());
196 if (!BaseIdxInit || !BaseIdxInit->getDef()->isSubClassOf("SubRegIndex"))
197 throw TGError(TheDef->getLoc(), "Invalid SubClassIndex in " +
199 CodeGenSubRegIndex *BaseIdx = RegBank.getSubRegIdx(BaseIdxInit->getDef());
201 // Resolve list of subreg indices into R2.
202 CodeGenRegister *R2 = this;
203 for (DagInit::const_arg_iterator di = Pat->arg_begin(),
204 de = Pat->arg_end(); di != de; ++di) {
205 DefInit *IdxInit = dynamic_cast<DefInit*>(*di);
206 if (!IdxInit || !IdxInit->getDef()->isSubClassOf("SubRegIndex"))
207 throw TGError(TheDef->getLoc(), "Invalid SubClassIndex in " +
209 CodeGenSubRegIndex *Idx = RegBank.getSubRegIdx(IdxInit->getDef());
210 const SubRegMap &R2Subs = R2->getSubRegs(RegBank);
211 SubRegMap::const_iterator ni = R2Subs.find(Idx);
212 if (ni == R2Subs.end())
213 throw TGError(TheDef->getLoc(), "Composite " + Pat->getAsString() +
214 " refers to bad index in " + R2->getName());
218 // Insert composite index. Allow overriding inherited indices etc.
219 SubRegs[BaseIdx] = R2;
221 // R2 is no longer an orphan.
225 // Now Orphans contains the inherited subregisters without a direct index.
226 // Create inferred indexes for all missing entries.
227 // Work backwards in the Indices vector in order to compose subregs bottom-up.
228 // Consider this subreg sequence:
230 // qsub_1 -> dsub_0 -> ssub_0
232 // The qsub_1 -> dsub_0 composition becomes dsub_2, so the ssub_0 register
233 // can be reached in two different ways:
238 // We pick the latter composition because another register may have [dsub_0,
239 // dsub_1, dsub_2] subregs without neccessarily having a qsub_1 subreg. The
240 // dsub_2 -> ssub_0 composition can be shared.
241 while (!Indices.empty() && !Orphans.empty()) {
242 CodeGenSubRegIndex *Idx = Indices.pop_back_val();
243 CodeGenRegister *SR = SubRegs[Idx];
244 const SubRegMap &Map = SR->getSubRegs(RegBank);
245 for (SubRegMap::const_iterator SI = Map.begin(), SE = Map.end(); SI != SE;
247 if (Orphans.erase(SI->second))
248 SubRegs[RegBank.getCompositeSubRegIndex(Idx, SI->first)] = SI->second;
251 // Initialize RegUnitList. A register with no subregisters creates its own
252 // unit. Otherwise, it inherits all its subregister's units. Because
253 // getSubRegs is called recursively, this processes the register hierarchy in
256 // TODO: We currently assume all register units correspond to a named "leaf"
257 // register. We should also unify register units for ad-hoc register
258 // aliases. This can be done by iteratively merging units for aliasing
259 // registers using a worklist.
260 assert(RegUnits.empty() && "Should only initialize RegUnits once");
261 if (SubRegs.empty()) {
262 RegUnits.push_back(RegBank.newRegUnit());
265 for (SubRegMap::const_iterator I = SubRegs.begin(), E = SubRegs.end();
267 // Strangely a register may have itself as a subreg (self-cycle) e.g. XMM.
268 CodeGenRegister *SR = I->second;
270 if (RegUnits.empty())
271 RegUnits.push_back(RegBank.newRegUnit());
274 // Merge the subregister's units into this register's RegUnits.
275 mergeRegUnits(RegUnits, SR->RegUnits);
282 CodeGenRegister::addSubRegsPreOrder(SetVector<const CodeGenRegister*> &OSet,
283 CodeGenRegBank &RegBank) const {
284 assert(SubRegsComplete && "Must precompute sub-registers");
285 std::vector<Record*> Indices = TheDef->getValueAsListOfDefs("SubRegIndices");
286 for (unsigned i = 0, e = Indices.size(); i != e; ++i) {
287 CodeGenSubRegIndex *Idx = RegBank.getSubRegIdx(Indices[i]);
288 CodeGenRegister *SR = SubRegs.find(Idx)->second;
290 SR->addSubRegsPreOrder(OSet, RegBank);
294 //===----------------------------------------------------------------------===//
296 //===----------------------------------------------------------------------===//
298 // A RegisterTuples def is used to generate pseudo-registers from lists of
299 // sub-registers. We provide a SetTheory expander class that returns the new
302 struct TupleExpander : SetTheory::Expander {
303 void expand(SetTheory &ST, Record *Def, SetTheory::RecSet &Elts) {
304 std::vector<Record*> Indices = Def->getValueAsListOfDefs("SubRegIndices");
305 unsigned Dim = Indices.size();
306 ListInit *SubRegs = Def->getValueAsListInit("SubRegs");
307 if (Dim != SubRegs->getSize())
308 throw TGError(Def->getLoc(), "SubRegIndices and SubRegs size mismatch");
310 throw TGError(Def->getLoc(), "Tuples must have at least 2 sub-registers");
312 // Evaluate the sub-register lists to be zipped.
313 unsigned Length = ~0u;
314 SmallVector<SetTheory::RecSet, 4> Lists(Dim);
315 for (unsigned i = 0; i != Dim; ++i) {
316 ST.evaluate(SubRegs->getElement(i), Lists[i]);
317 Length = std::min(Length, unsigned(Lists[i].size()));
323 // Precompute some types.
324 Record *RegisterCl = Def->getRecords().getClass("Register");
325 RecTy *RegisterRecTy = RecordRecTy::get(RegisterCl);
326 StringInit *BlankName = StringInit::get("");
329 for (unsigned n = 0; n != Length; ++n) {
331 Record *Proto = Lists[0][n];
332 std::vector<Init*> Tuple;
333 unsigned CostPerUse = 0;
334 for (unsigned i = 0; i != Dim; ++i) {
335 Record *Reg = Lists[i][n];
337 Name += Reg->getName();
338 Tuple.push_back(DefInit::get(Reg));
339 CostPerUse = std::max(CostPerUse,
340 unsigned(Reg->getValueAsInt("CostPerUse")));
343 // Create a new Record representing the synthesized register. This record
344 // is only for consumption by CodeGenRegister, it is not added to the
346 Record *NewReg = new Record(Name, Def->getLoc(), Def->getRecords());
349 // Copy Proto super-classes.
350 for (unsigned i = 0, e = Proto->getSuperClasses().size(); i != e; ++i)
351 NewReg->addSuperClass(Proto->getSuperClasses()[i]);
353 // Copy Proto fields.
354 for (unsigned i = 0, e = Proto->getValues().size(); i != e; ++i) {
355 RecordVal RV = Proto->getValues()[i];
357 // Skip existing fields, like NAME.
358 if (NewReg->getValue(RV.getNameInit()))
361 StringRef Field = RV.getName();
363 // Replace the sub-register list with Tuple.
364 if (Field == "SubRegs")
365 RV.setValue(ListInit::get(Tuple, RegisterRecTy));
367 // Provide a blank AsmName. MC hacks are required anyway.
368 if (Field == "AsmName")
369 RV.setValue(BlankName);
371 // CostPerUse is aggregated from all Tuple members.
372 if (Field == "CostPerUse")
373 RV.setValue(IntInit::get(CostPerUse));
375 // Composite registers are always covered by sub-registers.
376 if (Field == "CoveredBySubRegs")
377 RV.setValue(BitInit::get(true));
379 // Copy fields from the RegisterTuples def.
380 if (Field == "SubRegIndices" ||
381 Field == "CompositeIndices") {
382 NewReg->addValue(*Def->getValue(Field));
386 // Some fields get their default uninitialized value.
387 if (Field == "DwarfNumbers" ||
388 Field == "DwarfAlias" ||
389 Field == "Aliases") {
390 if (const RecordVal *DefRV = RegisterCl->getValue(Field))
391 NewReg->addValue(*DefRV);
395 // Everything else is copied from Proto.
396 NewReg->addValue(RV);
403 //===----------------------------------------------------------------------===//
404 // CodeGenRegisterClass
405 //===----------------------------------------------------------------------===//
407 CodeGenRegisterClass::CodeGenRegisterClass(CodeGenRegBank &RegBank, Record *R)
408 : TheDef(R), Name(R->getName()), EnumValue(-1) {
409 // Rename anonymous register classes.
410 if (R->getName().size() > 9 && R->getName()[9] == '.') {
411 static unsigned AnonCounter = 0;
412 R->setName("AnonRegClass_"+utostr(AnonCounter++));
415 std::vector<Record*> TypeList = R->getValueAsListOfDefs("RegTypes");
416 for (unsigned i = 0, e = TypeList.size(); i != e; ++i) {
417 Record *Type = TypeList[i];
418 if (!Type->isSubClassOf("ValueType"))
419 throw "RegTypes list member '" + Type->getName() +
420 "' does not derive from the ValueType class!";
421 VTs.push_back(getValueType(Type));
423 assert(!VTs.empty() && "RegisterClass must contain at least one ValueType!");
425 // Allocation order 0 is the full set. AltOrders provides others.
426 const SetTheory::RecVec *Elements = RegBank.getSets().expand(R);
427 ListInit *AltOrders = R->getValueAsListInit("AltOrders");
428 Orders.resize(1 + AltOrders->size());
430 // Default allocation order always contains all registers.
431 for (unsigned i = 0, e = Elements->size(); i != e; ++i) {
432 Orders[0].push_back((*Elements)[i]);
433 Members.insert(RegBank.getReg((*Elements)[i]));
436 // Alternative allocation orders may be subsets.
437 SetTheory::RecSet Order;
438 for (unsigned i = 0, e = AltOrders->size(); i != e; ++i) {
439 RegBank.getSets().evaluate(AltOrders->getElement(i), Order);
440 Orders[1 + i].append(Order.begin(), Order.end());
441 // Verify that all altorder members are regclass members.
442 while (!Order.empty()) {
443 CodeGenRegister *Reg = RegBank.getReg(Order.back());
446 throw TGError(R->getLoc(), " AltOrder register " + Reg->getName() +
447 " is not a class member");
451 // SubRegClasses is a list<dag> containing (RC, subregindex, ...) dags.
452 ListInit *SRC = R->getValueAsListInit("SubRegClasses");
453 for (ListInit::const_iterator i = SRC->begin(), e = SRC->end(); i != e; ++i) {
454 DagInit *DAG = dynamic_cast<DagInit*>(*i);
455 if (!DAG) throw "SubRegClasses must contain DAGs";
456 DefInit *DAGOp = dynamic_cast<DefInit*>(DAG->getOperator());
458 if (!DAGOp || !(RCRec = DAGOp->getDef())->isSubClassOf("RegisterClass"))
459 throw "Operator '" + DAG->getOperator()->getAsString() +
460 "' in SubRegClasses is not a RegisterClass";
461 // Iterate over args, all SubRegIndex instances.
462 for (DagInit::const_arg_iterator ai = DAG->arg_begin(), ae = DAG->arg_end();
464 DefInit *Idx = dynamic_cast<DefInit*>(*ai);
466 if (!Idx || !(IdxRec = Idx->getDef())->isSubClassOf("SubRegIndex"))
467 throw "Argument '" + (*ai)->getAsString() +
468 "' in SubRegClasses is not a SubRegIndex";
469 if (!SubRegClasses.insert(std::make_pair(IdxRec, RCRec)).second)
470 throw "SubRegIndex '" + IdxRec->getName() + "' mentioned twice";
474 // Allow targets to override the size in bits of the RegisterClass.
475 unsigned Size = R->getValueAsInt("Size");
477 Namespace = R->getValueAsString("Namespace");
478 SpillSize = Size ? Size : EVT(VTs[0]).getSizeInBits();
479 SpillAlignment = R->getValueAsInt("Alignment");
480 CopyCost = R->getValueAsInt("CopyCost");
481 Allocatable = R->getValueAsBit("isAllocatable");
482 AltOrderSelect = R->getValueAsString("AltOrderSelect");
485 // Create an inferred register class that was missing from the .td files.
486 // Most properties will be inherited from the closest super-class after the
487 // class structure has been computed.
488 CodeGenRegisterClass::CodeGenRegisterClass(StringRef Name, Key Props)
489 : Members(*Props.Members),
493 SpillSize(Props.SpillSize),
494 SpillAlignment(Props.SpillAlignment),
499 // Compute inherited propertied for a synthesized register class.
500 void CodeGenRegisterClass::inheritProperties(CodeGenRegBank &RegBank) {
501 assert(!getDef() && "Only synthesized classes can inherit properties");
502 assert(!SuperClasses.empty() && "Synthesized class without super class");
504 // The last super-class is the smallest one.
505 CodeGenRegisterClass &Super = *SuperClasses.back();
507 // Most properties are copied directly.
508 // Exceptions are members, size, and alignment
509 Namespace = Super.Namespace;
511 CopyCost = Super.CopyCost;
512 Allocatable = Super.Allocatable;
513 AltOrderSelect = Super.AltOrderSelect;
515 // Copy all allocation orders, filter out foreign registers from the larger
517 Orders.resize(Super.Orders.size());
518 for (unsigned i = 0, ie = Super.Orders.size(); i != ie; ++i)
519 for (unsigned j = 0, je = Super.Orders[i].size(); j != je; ++j)
520 if (contains(RegBank.getReg(Super.Orders[i][j])))
521 Orders[i].push_back(Super.Orders[i][j]);
524 bool CodeGenRegisterClass::contains(const CodeGenRegister *Reg) const {
525 return Members.count(Reg);
529 raw_ostream &operator<<(raw_ostream &OS, const CodeGenRegisterClass::Key &K) {
530 OS << "{ S=" << K.SpillSize << ", A=" << K.SpillAlignment;
531 for (CodeGenRegister::Set::const_iterator I = K.Members->begin(),
532 E = K.Members->end(); I != E; ++I)
533 OS << ", " << (*I)->getName();
538 // This is a simple lexicographical order that can be used to search for sets.
539 // It is not the same as the topological order provided by TopoOrderRC.
540 bool CodeGenRegisterClass::Key::
541 operator<(const CodeGenRegisterClass::Key &B) const {
542 assert(Members && B.Members);
543 if (*Members != *B.Members)
544 return *Members < *B.Members;
545 if (SpillSize != B.SpillSize)
546 return SpillSize < B.SpillSize;
547 return SpillAlignment < B.SpillAlignment;
550 // Returns true if RC is a strict subclass.
551 // RC is a sub-class of this class if it is a valid replacement for any
552 // instruction operand where a register of this classis required. It must
553 // satisfy these conditions:
555 // 1. All RC registers are also in this.
556 // 2. The RC spill size must not be smaller than our spill size.
557 // 3. RC spill alignment must be compatible with ours.
559 static bool testSubClass(const CodeGenRegisterClass *A,
560 const CodeGenRegisterClass *B) {
561 return A->SpillAlignment && B->SpillAlignment % A->SpillAlignment == 0 &&
562 A->SpillSize <= B->SpillSize &&
563 std::includes(A->getMembers().begin(), A->getMembers().end(),
564 B->getMembers().begin(), B->getMembers().end(),
565 CodeGenRegister::Less());
568 /// Sorting predicate for register classes. This provides a topological
569 /// ordering that arranges all register classes before their sub-classes.
571 /// Register classes with the same registers, spill size, and alignment form a
572 /// clique. They will be ordered alphabetically.
574 static int TopoOrderRC(const void *PA, const void *PB) {
575 const CodeGenRegisterClass *A = *(const CodeGenRegisterClass* const*)PA;
576 const CodeGenRegisterClass *B = *(const CodeGenRegisterClass* const*)PB;
580 // Order by descending set size. Note that the classes' allocation order may
581 // not have been computed yet. The Members set is always vaild.
582 if (A->getMembers().size() > B->getMembers().size())
584 if (A->getMembers().size() < B->getMembers().size())
587 // Order by ascending spill size.
588 if (A->SpillSize < B->SpillSize)
590 if (A->SpillSize > B->SpillSize)
593 // Order by ascending spill alignment.
594 if (A->SpillAlignment < B->SpillAlignment)
596 if (A->SpillAlignment > B->SpillAlignment)
599 // Finally order by name as a tie breaker.
600 return StringRef(A->getName()).compare(B->getName());
603 std::string CodeGenRegisterClass::getQualifiedName() const {
604 if (Namespace.empty())
607 return Namespace + "::" + getName();
610 // Compute sub-classes of all register classes.
611 // Assume the classes are ordered topologically.
612 void CodeGenRegisterClass::computeSubClasses(CodeGenRegBank &RegBank) {
613 ArrayRef<CodeGenRegisterClass*> RegClasses = RegBank.getRegClasses();
615 // Visit backwards so sub-classes are seen first.
616 for (unsigned rci = RegClasses.size(); rci; --rci) {
617 CodeGenRegisterClass &RC = *RegClasses[rci - 1];
618 RC.SubClasses.resize(RegClasses.size());
619 RC.SubClasses.set(RC.EnumValue);
621 // Normally, all subclasses have IDs >= rci, unless RC is part of a clique.
622 for (unsigned s = rci; s != RegClasses.size(); ++s) {
623 if (RC.SubClasses.test(s))
625 CodeGenRegisterClass *SubRC = RegClasses[s];
626 if (!testSubClass(&RC, SubRC))
628 // SubRC is a sub-class. Grap all its sub-classes so we won't have to
630 RC.SubClasses |= SubRC->SubClasses;
633 // Sweep up missed clique members. They will be immediately preceeding RC.
634 for (unsigned s = rci - 1; s && testSubClass(&RC, RegClasses[s - 1]); --s)
635 RC.SubClasses.set(s - 1);
638 // Compute the SuperClasses lists from the SubClasses vectors.
639 for (unsigned rci = 0; rci != RegClasses.size(); ++rci) {
640 const BitVector &SC = RegClasses[rci]->getSubClasses();
641 for (int s = SC.find_first(); s >= 0; s = SC.find_next(s)) {
642 if (unsigned(s) == rci)
644 RegClasses[s]->SuperClasses.push_back(RegClasses[rci]);
648 // With the class hierarchy in place, let synthesized register classes inherit
649 // properties from their closest super-class. The iteration order here can
650 // propagate properties down multiple levels.
651 for (unsigned rci = 0; rci != RegClasses.size(); ++rci)
652 if (!RegClasses[rci]->getDef())
653 RegClasses[rci]->inheritProperties(RegBank);
657 CodeGenRegisterClass::getSuperRegClasses(CodeGenSubRegIndex *SubIdx,
658 BitVector &Out) const {
659 DenseMap<CodeGenSubRegIndex*,
660 SmallPtrSet<CodeGenRegisterClass*, 8> >::const_iterator
661 FindI = SuperRegClasses.find(SubIdx);
662 if (FindI == SuperRegClasses.end())
664 for (SmallPtrSet<CodeGenRegisterClass*, 8>::const_iterator I =
665 FindI->second.begin(), E = FindI->second.end(); I != E; ++I)
666 Out.set((*I)->EnumValue);
670 //===----------------------------------------------------------------------===//
672 //===----------------------------------------------------------------------===//
674 CodeGenRegBank::CodeGenRegBank(RecordKeeper &Records) : Records(Records) {
675 // Configure register Sets to understand register classes and tuples.
676 Sets.addFieldExpander("RegisterClass", "MemberList");
677 Sets.addFieldExpander("CalleeSavedRegs", "SaveList");
678 Sets.addExpander("RegisterTuples", new TupleExpander());
680 // Read in the user-defined (named) sub-register indices.
681 // More indices will be synthesized later.
682 std::vector<Record*> SRIs = Records.getAllDerivedDefinitions("SubRegIndex");
683 std::sort(SRIs.begin(), SRIs.end(), LessRecord());
684 NumNamedIndices = SRIs.size();
685 for (unsigned i = 0, e = SRIs.size(); i != e; ++i)
686 getSubRegIdx(SRIs[i]);
687 // Build composite maps from ComposedOf fields.
688 for (unsigned i = 0, e = SubRegIndices.size(); i != e; ++i)
689 SubRegIndices[i]->updateComponents(*this);
691 // Read in the register definitions.
692 std::vector<Record*> Regs = Records.getAllDerivedDefinitions("Register");
693 std::sort(Regs.begin(), Regs.end(), LessRecord());
694 Registers.reserve(Regs.size());
695 // Assign the enumeration values.
696 for (unsigned i = 0, e = Regs.size(); i != e; ++i)
699 // Expand tuples and number the new registers.
700 std::vector<Record*> Tups =
701 Records.getAllDerivedDefinitions("RegisterTuples");
702 for (unsigned i = 0, e = Tups.size(); i != e; ++i) {
703 const std::vector<Record*> *TupRegs = Sets.expand(Tups[i]);
704 for (unsigned j = 0, je = TupRegs->size(); j != je; ++j)
705 getReg((*TupRegs)[j]);
708 // Precompute all sub-register maps now all the registers are known.
709 // This will create Composite entries for all inferred sub-register indices.
711 for (unsigned i = 0, e = Registers.size(); i != e; ++i)
712 Registers[i]->getSubRegs(*this);
714 // Read in register class definitions.
715 std::vector<Record*> RCs = Records.getAllDerivedDefinitions("RegisterClass");
717 throw std::string("No 'RegisterClass' subclasses defined!");
719 // Allocate user-defined register classes.
720 RegClasses.reserve(RCs.size());
721 for (unsigned i = 0, e = RCs.size(); i != e; ++i)
722 addToMaps(new CodeGenRegisterClass(*this, RCs[i]));
724 // Infer missing classes to create a full algebra.
725 computeInferredRegisterClasses();
727 // Order register classes topologically and assign enum values.
728 array_pod_sort(RegClasses.begin(), RegClasses.end(), TopoOrderRC);
729 for (unsigned i = 0, e = RegClasses.size(); i != e; ++i)
730 RegClasses[i]->EnumValue = i;
731 CodeGenRegisterClass::computeSubClasses(*this);
734 CodeGenSubRegIndex *CodeGenRegBank::getSubRegIdx(Record *Def) {
735 CodeGenSubRegIndex *&Idx = Def2SubRegIdx[Def];
738 Idx = new CodeGenSubRegIndex(Def, SubRegIndices.size() + 1);
739 SubRegIndices.push_back(Idx);
743 CodeGenRegister *CodeGenRegBank::getReg(Record *Def) {
744 CodeGenRegister *&Reg = Def2Reg[Def];
747 Reg = new CodeGenRegister(Def, Registers.size() + 1);
748 Registers.push_back(Reg);
752 void CodeGenRegBank::addToMaps(CodeGenRegisterClass *RC) {
753 RegClasses.push_back(RC);
755 if (Record *Def = RC->getDef())
756 Def2RC.insert(std::make_pair(Def, RC));
758 // Duplicate classes are rejected by insert().
759 // That's OK, we only care about the properties handled by CGRC::Key.
760 CodeGenRegisterClass::Key K(*RC);
761 Key2RC.insert(std::make_pair(K, RC));
764 // Create a synthetic sub-class if it is missing.
765 CodeGenRegisterClass*
766 CodeGenRegBank::getOrCreateSubClass(const CodeGenRegisterClass *RC,
767 const CodeGenRegister::Set *Members,
769 // Synthetic sub-class has the same size and alignment as RC.
770 CodeGenRegisterClass::Key K(Members, RC->SpillSize, RC->SpillAlignment);
771 RCKeyMap::const_iterator FoundI = Key2RC.find(K);
772 if (FoundI != Key2RC.end())
773 return FoundI->second;
775 // Sub-class doesn't exist, create a new one.
776 CodeGenRegisterClass *NewRC = new CodeGenRegisterClass(Name, K);
781 CodeGenRegisterClass *CodeGenRegBank::getRegClass(Record *Def) {
782 if (CodeGenRegisterClass *RC = Def2RC[Def])
785 throw TGError(Def->getLoc(), "Not a known RegisterClass!");
789 CodeGenRegBank::getCompositeSubRegIndex(CodeGenSubRegIndex *A,
790 CodeGenSubRegIndex *B) {
791 // Look for an existing entry.
792 CodeGenSubRegIndex *Comp = A->compose(B);
796 // None exists, synthesize one.
797 std::string Name = A->getName() + "_then_" + B->getName();
798 Comp = getSubRegIdx(new Record(Name, SMLoc(), Records));
799 A->addComposite(B, Comp);
803 void CodeGenRegBank::computeComposites() {
804 for (unsigned i = 0, e = Registers.size(); i != e; ++i) {
805 CodeGenRegister *Reg1 = Registers[i];
806 const CodeGenRegister::SubRegMap &SRM1 = Reg1->getSubRegs();
807 for (CodeGenRegister::SubRegMap::const_iterator i1 = SRM1.begin(),
808 e1 = SRM1.end(); i1 != e1; ++i1) {
809 CodeGenSubRegIndex *Idx1 = i1->first;
810 CodeGenRegister *Reg2 = i1->second;
811 // Ignore identity compositions.
814 const CodeGenRegister::SubRegMap &SRM2 = Reg2->getSubRegs();
815 // Try composing Idx1 with another SubRegIndex.
816 for (CodeGenRegister::SubRegMap::const_iterator i2 = SRM2.begin(),
817 e2 = SRM2.end(); i2 != e2; ++i2) {
818 CodeGenSubRegIndex *Idx2 = i2->first;
819 CodeGenRegister *Reg3 = i2->second;
820 // Ignore identity compositions.
823 // OK Reg1:IdxPair == Reg3. Find the index with Reg:Idx == Reg3.
824 for (CodeGenRegister::SubRegMap::const_iterator i1d = SRM1.begin(),
825 e1d = SRM1.end(); i1d != e1d; ++i1d) {
826 if (i1d->second == Reg3) {
827 // Conflicting composition? Emit a warning but allow it.
828 if (CodeGenSubRegIndex *Prev = Idx1->addComposite(Idx2, i1d->first))
829 errs() << "Warning: SubRegIndex " << Idx1->getQualifiedName()
830 << " and " << Idx2->getQualifiedName()
831 << " compose ambiguously as "
832 << Prev->getQualifiedName() << " or "
833 << i1d->first->getQualifiedName() << "\n";
840 // We don't care about the difference between (Idx1, Idx2) -> Idx2 and invalid
841 // compositions, so remove any mappings of that form.
842 for (unsigned i = 0, e = SubRegIndices.size(); i != e; ++i)
843 SubRegIndices[i]->cleanComposites();
846 // Compute sets of overlapping registers.
848 // The standard set is all super-registers and all sub-registers, but the
849 // target description can add arbitrary overlapping registers via the 'Aliases'
850 // field. This complicates things, but we can compute overlapping sets using
851 // the following rules:
853 // 1. The relation overlap(A, B) is reflexive and symmetric but not transitive.
855 // 2. overlap(A, B) implies overlap(A, S) for all S in supers(B).
859 // overlap(A, B) iff there exists:
860 // A' in { A, subregs(A) } and B' in { B, subregs(B) } such that:
861 // A' = B' or A' in aliases(B') or B' in aliases(A').
863 // Here subregs(A) is the full flattened sub-register set returned by
864 // A.getSubRegs() while aliases(A) is simply the special 'Aliases' field in the
865 // description of register A.
867 // This also implies that registers with a common sub-register are considered
868 // overlapping. This can happen when forming register pairs:
874 // In this case, we will infer an overlap between P0 and P1 because of the
875 // shared sub-register R1. There is no overlap between P0 and P2.
877 void CodeGenRegBank::
878 computeOverlaps(std::map<const CodeGenRegister*, CodeGenRegister::Set> &Map) {
881 // Collect overlaps that don't follow from rule 2.
882 for (unsigned i = 0, e = Registers.size(); i != e; ++i) {
883 CodeGenRegister *Reg = Registers[i];
884 CodeGenRegister::Set &Overlaps = Map[Reg];
886 // Reg overlaps itself.
887 Overlaps.insert(Reg);
889 // All super-registers overlap.
890 const CodeGenRegister::SuperRegList &Supers = Reg->getSuperRegs();
891 Overlaps.insert(Supers.begin(), Supers.end());
893 // Form symmetrical relations from the special Aliases[] lists.
894 std::vector<Record*> RegList = Reg->TheDef->getValueAsListOfDefs("Aliases");
895 for (unsigned i2 = 0, e2 = RegList.size(); i2 != e2; ++i2) {
896 CodeGenRegister *Reg2 = getReg(RegList[i2]);
897 CodeGenRegister::Set &Overlaps2 = Map[Reg2];
898 const CodeGenRegister::SuperRegList &Supers2 = Reg2->getSuperRegs();
899 // Reg overlaps Reg2 which implies it overlaps supers(Reg2).
900 Overlaps.insert(Reg2);
901 Overlaps.insert(Supers2.begin(), Supers2.end());
902 Overlaps2.insert(Reg);
903 Overlaps2.insert(Supers.begin(), Supers.end());
907 // Apply rule 2. and inherit all sub-register overlaps.
908 for (unsigned i = 0, e = Registers.size(); i != e; ++i) {
909 CodeGenRegister *Reg = Registers[i];
910 CodeGenRegister::Set &Overlaps = Map[Reg];
911 const CodeGenRegister::SubRegMap &SRM = Reg->getSubRegs();
912 for (CodeGenRegister::SubRegMap::const_iterator i2 = SRM.begin(),
913 e2 = SRM.end(); i2 != e2; ++i2) {
914 CodeGenRegister::Set &Overlaps2 = Map[i2->second];
915 Overlaps.insert(Overlaps2.begin(), Overlaps2.end());
920 void CodeGenRegBank::computeDerivedInfo() {
925 // Synthesize missing register class intersections.
927 // Make sure that sub-classes of RC exists such that getCommonSubClass(RC, X)
928 // returns a maximal register class for all X.
930 void CodeGenRegBank::inferCommonSubClass(CodeGenRegisterClass *RC) {
931 for (unsigned rci = 0, rce = RegClasses.size(); rci != rce; ++rci) {
932 CodeGenRegisterClass *RC1 = RC;
933 CodeGenRegisterClass *RC2 = RegClasses[rci];
937 // Compute the set intersection of RC1 and RC2.
938 const CodeGenRegister::Set &Memb1 = RC1->getMembers();
939 const CodeGenRegister::Set &Memb2 = RC2->getMembers();
940 CodeGenRegister::Set Intersection;
941 std::set_intersection(Memb1.begin(), Memb1.end(),
942 Memb2.begin(), Memb2.end(),
943 std::inserter(Intersection, Intersection.begin()),
944 CodeGenRegister::Less());
946 // Skip disjoint class pairs.
947 if (Intersection.empty())
950 // If RC1 and RC2 have different spill sizes or alignments, use the
951 // larger size for sub-classing. If they are equal, prefer RC1.
952 if (RC2->SpillSize > RC1->SpillSize ||
953 (RC2->SpillSize == RC1->SpillSize &&
954 RC2->SpillAlignment > RC1->SpillAlignment))
957 getOrCreateSubClass(RC1, &Intersection,
958 RC1->getName() + "_and_" + RC2->getName());
963 // Synthesize missing sub-classes for getSubClassWithSubReg().
965 // Make sure that the set of registers in RC with a given SubIdx sub-register
966 // form a register class. Update RC->SubClassWithSubReg.
968 void CodeGenRegBank::inferSubClassWithSubReg(CodeGenRegisterClass *RC) {
969 // Map SubRegIndex to set of registers in RC supporting that SubRegIndex.
970 typedef std::map<CodeGenSubRegIndex*, CodeGenRegister::Set,
971 CodeGenSubRegIndex::Less> SubReg2SetMap;
973 // Compute the set of registers supporting each SubRegIndex.
974 SubReg2SetMap SRSets;
975 for (CodeGenRegister::Set::const_iterator RI = RC->getMembers().begin(),
976 RE = RC->getMembers().end(); RI != RE; ++RI) {
977 const CodeGenRegister::SubRegMap &SRM = (*RI)->getSubRegs();
978 for (CodeGenRegister::SubRegMap::const_iterator I = SRM.begin(),
979 E = SRM.end(); I != E; ++I)
980 SRSets[I->first].insert(*RI);
983 // Find matching classes for all SRSets entries. Iterate in SubRegIndex
984 // numerical order to visit synthetic indices last.
985 for (unsigned sri = 0, sre = SubRegIndices.size(); sri != sre; ++sri) {
986 CodeGenSubRegIndex *SubIdx = SubRegIndices[sri];
987 SubReg2SetMap::const_iterator I = SRSets.find(SubIdx);
988 // Unsupported SubRegIndex. Skip it.
989 if (I == SRSets.end())
991 // In most cases, all RC registers support the SubRegIndex.
992 if (I->second.size() == RC->getMembers().size()) {
993 RC->setSubClassWithSubReg(SubIdx, RC);
996 // This is a real subset. See if we have a matching class.
997 CodeGenRegisterClass *SubRC =
998 getOrCreateSubClass(RC, &I->second,
999 RC->getName() + "_with_" + I->first->getName());
1000 RC->setSubClassWithSubReg(SubIdx, SubRC);
1005 // Synthesize missing sub-classes of RC for getMatchingSuperRegClass().
1007 // Create sub-classes of RC such that getMatchingSuperRegClass(RC, SubIdx, X)
1008 // has a maximal result for any SubIdx and any X >= FirstSubRegRC.
1011 void CodeGenRegBank::inferMatchingSuperRegClass(CodeGenRegisterClass *RC,
1012 unsigned FirstSubRegRC) {
1013 SmallVector<std::pair<const CodeGenRegister*,
1014 const CodeGenRegister*>, 16> SSPairs;
1016 // Iterate in SubRegIndex numerical order to visit synthetic indices last.
1017 for (unsigned sri = 0, sre = SubRegIndices.size(); sri != sre; ++sri) {
1018 CodeGenSubRegIndex *SubIdx = SubRegIndices[sri];
1019 // Skip indexes that aren't fully supported by RC's registers. This was
1020 // computed by inferSubClassWithSubReg() above which should have been
1022 if (RC->getSubClassWithSubReg(SubIdx) != RC)
1025 // Build list of (Super, Sub) pairs for this SubIdx.
1027 for (CodeGenRegister::Set::const_iterator RI = RC->getMembers().begin(),
1028 RE = RC->getMembers().end(); RI != RE; ++RI) {
1029 const CodeGenRegister *Super = *RI;
1030 const CodeGenRegister *Sub = Super->getSubRegs().find(SubIdx)->second;
1031 assert(Sub && "Missing sub-register");
1032 SSPairs.push_back(std::make_pair(Super, Sub));
1035 // Iterate over sub-register class candidates. Ignore classes created by
1036 // this loop. They will never be useful.
1037 for (unsigned rci = FirstSubRegRC, rce = RegClasses.size(); rci != rce;
1039 CodeGenRegisterClass *SubRC = RegClasses[rci];
1040 // Compute the subset of RC that maps into SubRC.
1041 CodeGenRegister::Set SubSet;
1042 for (unsigned i = 0, e = SSPairs.size(); i != e; ++i)
1043 if (SubRC->contains(SSPairs[i].second))
1044 SubSet.insert(SSPairs[i].first);
1047 // RC injects completely into SubRC.
1048 if (SubSet.size() == SSPairs.size()) {
1049 SubRC->addSuperRegClass(SubIdx, RC);
1052 // Only a subset of RC maps into SubRC. Make sure it is represented by a
1054 getOrCreateSubClass(RC, &SubSet, RC->getName() +
1055 "_with_" + SubIdx->getName() +
1056 "_in_" + SubRC->getName());
1063 // Infer missing register classes.
1065 void CodeGenRegBank::computeInferredRegisterClasses() {
1066 // When this function is called, the register classes have not been sorted
1067 // and assigned EnumValues yet. That means getSubClasses(),
1068 // getSuperClasses(), and hasSubClass() functions are defunct.
1069 unsigned FirstNewRC = RegClasses.size();
1071 // Visit all register classes, including the ones being added by the loop.
1072 for (unsigned rci = 0; rci != RegClasses.size(); ++rci) {
1073 CodeGenRegisterClass *RC = RegClasses[rci];
1075 // Synthesize answers for getSubClassWithSubReg().
1076 inferSubClassWithSubReg(RC);
1078 // Synthesize answers for getCommonSubClass().
1079 inferCommonSubClass(RC);
1081 // Synthesize answers for getMatchingSuperRegClass().
1082 inferMatchingSuperRegClass(RC);
1084 // New register classes are created while this loop is running, and we need
1085 // to visit all of them. I particular, inferMatchingSuperRegClass needs
1086 // to match old super-register classes with sub-register classes created
1087 // after inferMatchingSuperRegClass was called. At this point,
1088 // inferMatchingSuperRegClass has checked SuperRC = [0..rci] with SubRC =
1089 // [0..FirstNewRC). We need to cover SubRC = [FirstNewRC..rci].
1090 if (rci + 1 == FirstNewRC) {
1091 unsigned NextNewRC = RegClasses.size();
1092 for (unsigned rci2 = 0; rci2 != FirstNewRC; ++rci2)
1093 inferMatchingSuperRegClass(RegClasses[rci2], FirstNewRC);
1094 FirstNewRC = NextNewRC;
1099 /// getRegisterClassForRegister - Find the register class that contains the
1100 /// specified physical register. If the register is not in a register class,
1101 /// return null. If the register is in multiple classes, and the classes have a
1102 /// superset-subset relationship and the same set of types, return the
1103 /// superclass. Otherwise return null.
1104 const CodeGenRegisterClass*
1105 CodeGenRegBank::getRegClassForRegister(Record *R) {
1106 const CodeGenRegister *Reg = getReg(R);
1107 ArrayRef<CodeGenRegisterClass*> RCs = getRegClasses();
1108 const CodeGenRegisterClass *FoundRC = 0;
1109 for (unsigned i = 0, e = RCs.size(); i != e; ++i) {
1110 const CodeGenRegisterClass &RC = *RCs[i];
1111 if (!RC.contains(Reg))
1114 // If this is the first class that contains the register,
1115 // make a note of it and go on to the next class.
1121 // If a register's classes have different types, return null.
1122 if (RC.getValueTypes() != FoundRC->getValueTypes())
1125 // Check to see if the previously found class that contains
1126 // the register is a subclass of the current class. If so,
1127 // prefer the superclass.
1128 if (RC.hasSubClass(FoundRC)) {
1133 // Check to see if the previously found class that contains
1134 // the register is a superclass of the current class. If so,
1135 // prefer the superclass.
1136 if (FoundRC->hasSubClass(&RC))
1139 // Multiple classes, and neither is a superclass of the other.
1146 BitVector CodeGenRegBank::computeCoveredRegisters(ArrayRef<Record*> Regs) {
1147 SetVector<const CodeGenRegister*> Set;
1149 // First add Regs with all sub-registers.
1150 for (unsigned i = 0, e = Regs.size(); i != e; ++i) {
1151 CodeGenRegister *Reg = getReg(Regs[i]);
1152 if (Set.insert(Reg))
1153 // Reg is new, add all sub-registers.
1154 // The pre-ordering is not important here.
1155 Reg->addSubRegsPreOrder(Set, *this);
1158 // Second, find all super-registers that are completely covered by the set.
1159 for (unsigned i = 0; i != Set.size(); ++i) {
1160 const CodeGenRegister::SuperRegList &SR = Set[i]->getSuperRegs();
1161 for (unsigned j = 0, e = SR.size(); j != e; ++j) {
1162 const CodeGenRegister *Super = SR[j];
1163 if (!Super->CoveredBySubRegs || Set.count(Super))
1165 // This new super-register is covered by its sub-registers.
1166 bool AllSubsInSet = true;
1167 const CodeGenRegister::SubRegMap &SRM = Super->getSubRegs();
1168 for (CodeGenRegister::SubRegMap::const_iterator I = SRM.begin(),
1169 E = SRM.end(); I != E; ++I)
1170 if (!Set.count(I->second)) {
1171 AllSubsInSet = false;
1174 // All sub-registers in Set, add Super as well.
1175 // We will visit Super later to recheck its super-registers.
1181 // Convert to BitVector.
1182 BitVector BV(Registers.size() + 1);
1183 for (unsigned i = 0, e = Set.size(); i != e; ++i)
1184 BV.set(Set[i]->EnumValue);