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/IntEqClasses.h"
19 #include "llvm/ADT/SmallVector.h"
20 #include "llvm/ADT/STLExtras.h"
21 #include "llvm/ADT/StringExtras.h"
22 #include "llvm/ADT/Twine.h"
26 //===----------------------------------------------------------------------===//
28 //===----------------------------------------------------------------------===//
30 CodeGenSubRegIndex::CodeGenSubRegIndex(Record *R, unsigned Enum)
31 : TheDef(R), EnumValue(Enum), LaneMask(0) {
33 if (R->getValue("Namespace"))
34 Namespace = R->getValueAsString("Namespace");
37 CodeGenSubRegIndex::CodeGenSubRegIndex(StringRef N, StringRef Nspace,
39 : TheDef(0), Name(N), Namespace(Nspace), EnumValue(Enum), LaneMask(0) {
42 std::string CodeGenSubRegIndex::getQualifiedName() const {
43 std::string N = getNamespace();
50 void CodeGenSubRegIndex::updateComponents(CodeGenRegBank &RegBank) {
54 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 std::vector<Record*> Parts =
66 TheDef->getValueAsListOfDefs("CoveringSubRegIndices");
69 throw TGError(TheDef->getLoc(),
70 "CoveredBySubRegs must have two or more entries");
71 SmallVector<CodeGenSubRegIndex*, 8> IdxParts;
72 for (unsigned i = 0, e = Parts.size(); i != e; ++i)
73 IdxParts.push_back(RegBank.getSubRegIdx(Parts[i]));
74 RegBank.addConcatSubRegIndex(IdxParts, this);
78 unsigned CodeGenSubRegIndex::computeLaneMask() {
83 // Recursion guard, shouldn't be required.
86 // The lane mask is simply the union of all sub-indices.
88 for (CompMap::iterator I = Composed.begin(), E = Composed.end(); I != E; ++I)
89 M |= I->second->computeLaneMask();
90 assert(M && "Missing lane mask, sub-register cycle?");
95 //===----------------------------------------------------------------------===//
97 //===----------------------------------------------------------------------===//
99 CodeGenRegister::CodeGenRegister(Record *R, unsigned Enum)
102 CostPerUse(R->getValueAsInt("CostPerUse")),
103 CoveredBySubRegs(R->getValueAsBit("CoveredBySubRegs")),
104 NumNativeRegUnits(0),
105 SubRegsComplete(false),
106 SuperRegsComplete(false),
110 void CodeGenRegister::buildObjectGraph(CodeGenRegBank &RegBank) {
111 std::vector<Record*> SRIs = TheDef->getValueAsListOfDefs("SubRegIndices");
112 std::vector<Record*> SRs = TheDef->getValueAsListOfDefs("SubRegs");
114 if (SRIs.size() != SRs.size())
115 throw TGError(TheDef->getLoc(),
116 "SubRegs and SubRegIndices must have the same size");
118 for (unsigned i = 0, e = SRIs.size(); i != e; ++i) {
119 ExplicitSubRegIndices.push_back(RegBank.getSubRegIdx(SRIs[i]));
120 ExplicitSubRegs.push_back(RegBank.getReg(SRs[i]));
123 // Also compute leading super-registers. Each register has a list of
124 // covered-by-subregs super-registers where it appears as the first explicit
127 // This is used by computeSecondarySubRegs() to find candidates.
128 if (CoveredBySubRegs && !ExplicitSubRegs.empty())
129 ExplicitSubRegs.front()->LeadingSuperRegs.push_back(this);
131 // Add ad hoc alias links. This is a symmetric relationship between two
132 // registers, so build a symmetric graph by adding links in both ends.
133 std::vector<Record*> Aliases = TheDef->getValueAsListOfDefs("Aliases");
134 for (unsigned i = 0, e = Aliases.size(); i != e; ++i) {
135 CodeGenRegister *Reg = RegBank.getReg(Aliases[i]);
136 ExplicitAliases.push_back(Reg);
137 Reg->ExplicitAliases.push_back(this);
141 const std::string &CodeGenRegister::getName() const {
142 return TheDef->getName();
146 // Iterate over all register units in a set of registers.
147 class RegUnitIterator {
148 CodeGenRegister::Set::const_iterator RegI, RegE;
149 CodeGenRegister::RegUnitList::const_iterator UnitI, UnitE;
152 RegUnitIterator(const CodeGenRegister::Set &Regs):
153 RegI(Regs.begin()), RegE(Regs.end()), UnitI(), UnitE() {
156 UnitI = (*RegI)->getRegUnits().begin();
157 UnitE = (*RegI)->getRegUnits().end();
162 bool isValid() const { return UnitI != UnitE; }
164 unsigned operator* () const { assert(isValid()); return *UnitI; }
166 const CodeGenRegister *getReg() const { assert(isValid()); return *RegI; }
168 /// Preincrement. Move to the next unit.
170 assert(isValid() && "Cannot advance beyond the last operand");
177 while (UnitI == UnitE) {
180 UnitI = (*RegI)->getRegUnits().begin();
181 UnitE = (*RegI)->getRegUnits().end();
187 // Merge two RegUnitLists maintaining the order and removing duplicates.
188 // Overwrites MergedRU in the process.
189 static void mergeRegUnits(CodeGenRegister::RegUnitList &MergedRU,
190 const CodeGenRegister::RegUnitList &RRU) {
191 CodeGenRegister::RegUnitList LRU = MergedRU;
193 std::set_union(LRU.begin(), LRU.end(), RRU.begin(), RRU.end(),
194 std::back_inserter(MergedRU));
197 // Return true of this unit appears in RegUnits.
198 static bool hasRegUnit(CodeGenRegister::RegUnitList &RegUnits, unsigned Unit) {
199 return std::count(RegUnits.begin(), RegUnits.end(), Unit);
202 // Inherit register units from subregisters.
203 // Return true if the RegUnits changed.
204 bool CodeGenRegister::inheritRegUnits(CodeGenRegBank &RegBank) {
205 unsigned OldNumUnits = RegUnits.size();
206 for (SubRegMap::const_iterator I = SubRegs.begin(), E = SubRegs.end();
208 CodeGenRegister *SR = I->second;
209 // Merge the subregister's units into this register's RegUnits.
210 mergeRegUnits(RegUnits, SR->RegUnits);
212 return OldNumUnits != RegUnits.size();
215 const CodeGenRegister::SubRegMap &
216 CodeGenRegister::computeSubRegs(CodeGenRegBank &RegBank) {
217 // Only compute this map once.
220 SubRegsComplete = true;
222 // First insert the explicit subregs and make sure they are fully indexed.
223 for (unsigned i = 0, e = ExplicitSubRegs.size(); i != e; ++i) {
224 CodeGenRegister *SR = ExplicitSubRegs[i];
225 CodeGenSubRegIndex *Idx = ExplicitSubRegIndices[i];
226 if (!SubRegs.insert(std::make_pair(Idx, SR)).second)
227 throw TGError(TheDef->getLoc(), "SubRegIndex " + Idx->getName() +
228 " appears twice in Register " + getName());
229 // Map explicit sub-registers first, so the names take precedence.
230 // The inherited sub-registers are mapped below.
231 SubReg2Idx.insert(std::make_pair(SR, Idx));
234 // Keep track of inherited subregs and how they can be reached.
235 SmallPtrSet<CodeGenRegister*, 8> Orphans;
237 // Clone inherited subregs and place duplicate entries in Orphans.
238 // Here the order is important - earlier subregs take precedence.
239 for (unsigned i = 0, e = ExplicitSubRegs.size(); i != e; ++i) {
240 CodeGenRegister *SR = ExplicitSubRegs[i];
241 const SubRegMap &Map = SR->computeSubRegs(RegBank);
243 for (SubRegMap::const_iterator SI = Map.begin(), SE = Map.end(); SI != SE;
245 if (!SubRegs.insert(*SI).second)
246 Orphans.insert(SI->second);
250 // Expand any composed subreg indices.
251 // If dsub_2 has ComposedOf = [qsub_1, dsub_0], and this register has a
252 // qsub_1 subreg, add a dsub_2 subreg. Keep growing Indices and process
253 // expanded subreg indices recursively.
254 SmallVector<CodeGenSubRegIndex*, 8> Indices = ExplicitSubRegIndices;
255 for (unsigned i = 0; i != Indices.size(); ++i) {
256 CodeGenSubRegIndex *Idx = Indices[i];
257 const CodeGenSubRegIndex::CompMap &Comps = Idx->getComposites();
258 CodeGenRegister *SR = SubRegs[Idx];
259 const SubRegMap &Map = SR->computeSubRegs(RegBank);
261 // Look at the possible compositions of Idx.
262 // They may not all be supported by SR.
263 for (CodeGenSubRegIndex::CompMap::const_iterator I = Comps.begin(),
264 E = Comps.end(); I != E; ++I) {
265 SubRegMap::const_iterator SRI = Map.find(I->first);
266 if (SRI == Map.end())
267 continue; // Idx + I->first doesn't exist in SR.
268 // Add I->second as a name for the subreg SRI->second, assuming it is
269 // orphaned, and the name isn't already used for something else.
270 if (SubRegs.count(I->second) || !Orphans.erase(SRI->second))
272 // We found a new name for the orphaned sub-register.
273 SubRegs.insert(std::make_pair(I->second, SRI->second));
274 Indices.push_back(I->second);
278 // Now Orphans contains the inherited subregisters without a direct index.
279 // Create inferred indexes for all missing entries.
280 // Work backwards in the Indices vector in order to compose subregs bottom-up.
281 // Consider this subreg sequence:
283 // qsub_1 -> dsub_0 -> ssub_0
285 // The qsub_1 -> dsub_0 composition becomes dsub_2, so the ssub_0 register
286 // can be reached in two different ways:
291 // We pick the latter composition because another register may have [dsub_0,
292 // dsub_1, dsub_2] subregs without necessarily having a qsub_1 subreg. The
293 // dsub_2 -> ssub_0 composition can be shared.
294 while (!Indices.empty() && !Orphans.empty()) {
295 CodeGenSubRegIndex *Idx = Indices.pop_back_val();
296 CodeGenRegister *SR = SubRegs[Idx];
297 const SubRegMap &Map = SR->computeSubRegs(RegBank);
298 for (SubRegMap::const_iterator SI = Map.begin(), SE = Map.end(); SI != SE;
300 if (Orphans.erase(SI->second))
301 SubRegs[RegBank.getCompositeSubRegIndex(Idx, SI->first)] = SI->second;
304 // Compute the inverse SubReg -> Idx map.
305 for (SubRegMap::const_iterator SI = SubRegs.begin(), SE = SubRegs.end();
307 if (SI->second == this) {
310 Loc = TheDef->getLoc();
311 throw TGError(Loc, "Register " + getName() +
312 " has itself as a sub-register");
314 // Ensure that every sub-register has a unique name.
315 DenseMap<const CodeGenRegister*, CodeGenSubRegIndex*>::iterator Ins =
316 SubReg2Idx.insert(std::make_pair(SI->second, SI->first)).first;
317 if (Ins->second == SI->first)
319 // Trouble: Two different names for SI->second.
322 Loc = TheDef->getLoc();
323 throw TGError(Loc, "Sub-register can't have two names: " +
324 SI->second->getName() + " available as " +
325 SI->first->getName() + " and " + Ins->second->getName());
328 // Derive possible names for sub-register concatenations from any explicit
329 // sub-registers. By doing this before computeSecondarySubRegs(), we ensure
330 // that getConcatSubRegIndex() won't invent any concatenated indices that the
331 // user already specified.
332 for (unsigned i = 0, e = ExplicitSubRegs.size(); i != e; ++i) {
333 CodeGenRegister *SR = ExplicitSubRegs[i];
334 if (!SR->CoveredBySubRegs || SR->ExplicitSubRegs.size() <= 1)
337 // SR is composed of multiple sub-regs. Find their names in this register.
338 SmallVector<CodeGenSubRegIndex*, 8> Parts;
339 for (unsigned j = 0, e = SR->ExplicitSubRegs.size(); j != e; ++j)
340 Parts.push_back(getSubRegIndex(SR->ExplicitSubRegs[j]));
342 // Offer this as an existing spelling for the concatenation of Parts.
343 RegBank.addConcatSubRegIndex(Parts, ExplicitSubRegIndices[i]);
346 // Initialize RegUnitList. Because getSubRegs is called recursively, this
347 // processes the register hierarchy in postorder.
349 // Inherit all sub-register units. It is good enough to look at the explicit
350 // sub-registers, the other registers won't contribute any more units.
351 for (unsigned i = 0, e = ExplicitSubRegs.size(); i != e; ++i) {
352 CodeGenRegister *SR = ExplicitSubRegs[i];
353 // Explicit sub-registers are usually disjoint, so this is a good way of
354 // computing the union. We may pick up a few duplicates that will be
356 unsigned N = RegUnits.size();
357 RegUnits.append(SR->RegUnits.begin(), SR->RegUnits.end());
358 std::inplace_merge(RegUnits.begin(), RegUnits.begin() + N, RegUnits.end());
360 RegUnits.erase(std::unique(RegUnits.begin(), RegUnits.end()), RegUnits.end());
362 // Absent any ad hoc aliasing, we create one register unit per leaf register.
363 // These units correspond to the maximal cliques in the register overlap
364 // graph which is optimal.
366 // When there is ad hoc aliasing, we simply create one unit per edge in the
367 // undirected ad hoc aliasing graph. Technically, we could do better by
368 // identifying maximal cliques in the ad hoc graph, but cliques larger than 2
369 // are extremely rare anyway (I've never seen one), so we don't bother with
370 // the added complexity.
371 for (unsigned i = 0, e = ExplicitAliases.size(); i != e; ++i) {
372 CodeGenRegister *AR = ExplicitAliases[i];
373 // Only visit each edge once.
374 if (AR->SubRegsComplete)
376 // Create a RegUnit representing this alias edge, and add it to both
378 unsigned Unit = RegBank.newRegUnit(this, AR);
379 RegUnits.push_back(Unit);
380 AR->RegUnits.push_back(Unit);
383 // Finally, create units for leaf registers without ad hoc aliases. Note that
384 // a leaf register with ad hoc aliases doesn't get its own unit - it isn't
385 // necessary. This means the aliasing leaf registers can share a single unit.
386 if (RegUnits.empty())
387 RegUnits.push_back(RegBank.newRegUnit(this));
389 // We have now computed the native register units. More may be adopted later
390 // for balancing purposes.
391 NumNativeRegUnits = RegUnits.size();
396 // In a register that is covered by its sub-registers, try to find redundant
397 // sub-registers. For example:
403 // We can infer that D1_D2 is also a sub-register, even if it wasn't named in
404 // the register definition.
406 // The explicitly specified registers form a tree. This function discovers
407 // sub-register relationships that would force a DAG.
409 void CodeGenRegister::computeSecondarySubRegs(CodeGenRegBank &RegBank) {
410 // Collect new sub-registers first, add them later.
411 SmallVector<SubRegMap::value_type, 8> NewSubRegs;
413 // Look at the leading super-registers of each sub-register. Those are the
414 // candidates for new sub-registers, assuming they are fully contained in
416 for (SubRegMap::iterator I = SubRegs.begin(), E = SubRegs.end(); I != E; ++I){
417 const CodeGenRegister *SubReg = I->second;
418 const CodeGenRegister::SuperRegList &Leads = SubReg->LeadingSuperRegs;
419 for (unsigned i = 0, e = Leads.size(); i != e; ++i) {
420 CodeGenRegister *Cand = const_cast<CodeGenRegister*>(Leads[i]);
421 // Already got this sub-register?
422 if (Cand == this || getSubRegIndex(Cand))
424 // Check if each component of Cand is already a sub-register.
425 // We know that the first component is I->second, and is present with the
427 SmallVector<CodeGenSubRegIndex*, 8> Parts(1, I->first);
428 assert(!Cand->ExplicitSubRegs.empty() &&
429 "Super-register has no sub-registers");
430 for (unsigned j = 1, e = Cand->ExplicitSubRegs.size(); j != e; ++j) {
431 if (CodeGenSubRegIndex *Idx = getSubRegIndex(Cand->ExplicitSubRegs[j]))
432 Parts.push_back(Idx);
434 // Sub-register doesn't exist.
439 // If some Cand sub-register is not part of this register, or if Cand only
440 // has one sub-register, there is nothing to do.
441 if (Parts.size() <= 1)
444 // Each part of Cand is a sub-register of this. Make the full Cand also
445 // a sub-register with a concatenated sub-register index.
446 CodeGenSubRegIndex *Concat= RegBank.getConcatSubRegIndex(Parts);
447 NewSubRegs.push_back(std::make_pair(Concat, Cand));
451 // Now add all the new sub-registers.
452 for (unsigned i = 0, e = NewSubRegs.size(); i != e; ++i) {
453 // Don't add Cand if another sub-register is already using the index.
454 if (!SubRegs.insert(NewSubRegs[i]).second)
457 CodeGenSubRegIndex *NewIdx = NewSubRegs[i].first;
458 CodeGenRegister *NewSubReg = NewSubRegs[i].second;
459 SubReg2Idx.insert(std::make_pair(NewSubReg, NewIdx));
462 // Create sub-register index composition maps for the synthesized indices.
463 for (unsigned i = 0, e = NewSubRegs.size(); i != e; ++i) {
464 CodeGenSubRegIndex *NewIdx = NewSubRegs[i].first;
465 CodeGenRegister *NewSubReg = NewSubRegs[i].second;
466 for (SubRegMap::const_iterator SI = NewSubReg->SubRegs.begin(),
467 SE = NewSubReg->SubRegs.end(); SI != SE; ++SI) {
468 CodeGenSubRegIndex *SubIdx = getSubRegIndex(SI->second);
470 throw TGError(TheDef->getLoc(), "No SubRegIndex for " +
471 SI->second->getName() + " in " + getName());
472 NewIdx->addComposite(SI->first, SubIdx);
477 void CodeGenRegister::computeSuperRegs(CodeGenRegBank &RegBank) {
478 // Only visit each register once.
479 if (SuperRegsComplete)
481 SuperRegsComplete = true;
483 // Make sure all sub-registers have been visited first, so the super-reg
484 // lists will be topologically ordered.
485 for (SubRegMap::const_iterator I = SubRegs.begin(), E = SubRegs.end();
487 I->second->computeSuperRegs(RegBank);
489 // Now add this as a super-register on all sub-registers.
490 // Also compute the TopoSigId in post-order.
492 for (SubRegMap::const_iterator I = SubRegs.begin(), E = SubRegs.end();
494 // Topological signature computed from SubIdx, TopoId(SubReg).
495 // Loops and idempotent indices have TopoSig = ~0u.
496 Id.push_back(I->first->EnumValue);
497 Id.push_back(I->second->TopoSig);
499 // Don't add duplicate entries.
500 if (!I->second->SuperRegs.empty() && I->second->SuperRegs.back() == this)
502 I->second->SuperRegs.push_back(this);
504 TopoSig = RegBank.getTopoSig(Id);
508 CodeGenRegister::addSubRegsPreOrder(SetVector<const CodeGenRegister*> &OSet,
509 CodeGenRegBank &RegBank) const {
510 assert(SubRegsComplete && "Must precompute sub-registers");
511 for (unsigned i = 0, e = ExplicitSubRegs.size(); i != e; ++i) {
512 CodeGenRegister *SR = ExplicitSubRegs[i];
514 SR->addSubRegsPreOrder(OSet, RegBank);
516 // Add any secondary sub-registers that weren't part of the explicit tree.
517 for (SubRegMap::const_iterator I = SubRegs.begin(), E = SubRegs.end();
519 OSet.insert(I->second);
522 // Compute overlapping registers.
524 // The standard set is all super-registers and all sub-registers, but the
525 // target description can add arbitrary overlapping registers via the 'Aliases'
526 // field. This complicates things, but we can compute overlapping sets using
527 // the following rules:
529 // 1. The relation overlap(A, B) is reflexive and symmetric but not transitive.
531 // 2. overlap(A, B) implies overlap(A, S) for all S in supers(B).
535 // overlap(A, B) iff there exists:
536 // A' in { A, subregs(A) } and B' in { B, subregs(B) } such that:
537 // A' = B' or A' in aliases(B') or B' in aliases(A').
539 // Here subregs(A) is the full flattened sub-register set returned by
540 // A.getSubRegs() while aliases(A) is simply the special 'Aliases' field in the
541 // description of register A.
543 // This also implies that registers with a common sub-register are considered
544 // overlapping. This can happen when forming register pairs:
550 // In this case, we will infer an overlap between P0 and P1 because of the
551 // shared sub-register R1. There is no overlap between P0 and P2.
553 void CodeGenRegister::computeOverlaps(CodeGenRegister::Set &Overlaps,
554 const CodeGenRegBank &RegBank) const {
555 assert(!RegUnits.empty() && "Compute register units before overlaps.");
557 // Register units are assigned such that the overlapping registers are the
558 // super-registers of the root registers of the register units.
559 for (unsigned rui = 0, rue = RegUnits.size(); rui != rue; ++rui) {
560 const RegUnit &RU = RegBank.getRegUnit(RegUnits[rui]);
561 ArrayRef<const CodeGenRegister*> Roots = RU.getRoots();
562 for (unsigned ri = 0, re = Roots.size(); ri != re; ++ri) {
563 const CodeGenRegister *Root = Roots[ri];
564 Overlaps.insert(Root);
565 ArrayRef<const CodeGenRegister*> Supers = Root->getSuperRegs();
566 Overlaps.insert(Supers.begin(), Supers.end());
571 // Get the sum of this register's unit weights.
572 unsigned CodeGenRegister::getWeight(const CodeGenRegBank &RegBank) const {
574 for (RegUnitList::const_iterator I = RegUnits.begin(), E = RegUnits.end();
576 Weight += RegBank.getRegUnit(*I).Weight;
581 //===----------------------------------------------------------------------===//
583 //===----------------------------------------------------------------------===//
585 // A RegisterTuples def is used to generate pseudo-registers from lists of
586 // sub-registers. We provide a SetTheory expander class that returns the new
589 struct TupleExpander : SetTheory::Expander {
590 void expand(SetTheory &ST, Record *Def, SetTheory::RecSet &Elts) {
591 std::vector<Record*> Indices = Def->getValueAsListOfDefs("SubRegIndices");
592 unsigned Dim = Indices.size();
593 ListInit *SubRegs = Def->getValueAsListInit("SubRegs");
594 if (Dim != SubRegs->getSize())
595 throw TGError(Def->getLoc(), "SubRegIndices and SubRegs size mismatch");
597 throw TGError(Def->getLoc(), "Tuples must have at least 2 sub-registers");
599 // Evaluate the sub-register lists to be zipped.
600 unsigned Length = ~0u;
601 SmallVector<SetTheory::RecSet, 4> Lists(Dim);
602 for (unsigned i = 0; i != Dim; ++i) {
603 ST.evaluate(SubRegs->getElement(i), Lists[i]);
604 Length = std::min(Length, unsigned(Lists[i].size()));
610 // Precompute some types.
611 Record *RegisterCl = Def->getRecords().getClass("Register");
612 RecTy *RegisterRecTy = RecordRecTy::get(RegisterCl);
613 StringInit *BlankName = StringInit::get("");
616 for (unsigned n = 0; n != Length; ++n) {
618 Record *Proto = Lists[0][n];
619 std::vector<Init*> Tuple;
620 unsigned CostPerUse = 0;
621 for (unsigned i = 0; i != Dim; ++i) {
622 Record *Reg = Lists[i][n];
624 Name += Reg->getName();
625 Tuple.push_back(DefInit::get(Reg));
626 CostPerUse = std::max(CostPerUse,
627 unsigned(Reg->getValueAsInt("CostPerUse")));
630 // Create a new Record representing the synthesized register. This record
631 // is only for consumption by CodeGenRegister, it is not added to the
633 Record *NewReg = new Record(Name, Def->getLoc(), Def->getRecords());
636 // Copy Proto super-classes.
637 for (unsigned i = 0, e = Proto->getSuperClasses().size(); i != e; ++i)
638 NewReg->addSuperClass(Proto->getSuperClasses()[i]);
640 // Copy Proto fields.
641 for (unsigned i = 0, e = Proto->getValues().size(); i != e; ++i) {
642 RecordVal RV = Proto->getValues()[i];
644 // Skip existing fields, like NAME.
645 if (NewReg->getValue(RV.getNameInit()))
648 StringRef Field = RV.getName();
650 // Replace the sub-register list with Tuple.
651 if (Field == "SubRegs")
652 RV.setValue(ListInit::get(Tuple, RegisterRecTy));
654 // Provide a blank AsmName. MC hacks are required anyway.
655 if (Field == "AsmName")
656 RV.setValue(BlankName);
658 // CostPerUse is aggregated from all Tuple members.
659 if (Field == "CostPerUse")
660 RV.setValue(IntInit::get(CostPerUse));
662 // Composite registers are always covered by sub-registers.
663 if (Field == "CoveredBySubRegs")
664 RV.setValue(BitInit::get(true));
666 // Copy fields from the RegisterTuples def.
667 if (Field == "SubRegIndices" ||
668 Field == "CompositeIndices") {
669 NewReg->addValue(*Def->getValue(Field));
673 // Some fields get their default uninitialized value.
674 if (Field == "DwarfNumbers" ||
675 Field == "DwarfAlias" ||
676 Field == "Aliases") {
677 if (const RecordVal *DefRV = RegisterCl->getValue(Field))
678 NewReg->addValue(*DefRV);
682 // Everything else is copied from Proto.
683 NewReg->addValue(RV);
690 //===----------------------------------------------------------------------===//
691 // CodeGenRegisterClass
692 //===----------------------------------------------------------------------===//
694 CodeGenRegisterClass::CodeGenRegisterClass(CodeGenRegBank &RegBank, Record *R)
697 TopoSigs(RegBank.getNumTopoSigs()),
699 // Rename anonymous register classes.
700 if (R->getName().size() > 9 && R->getName()[9] == '.') {
701 static unsigned AnonCounter = 0;
702 R->setName("AnonRegClass_"+utostr(AnonCounter++));
705 std::vector<Record*> TypeList = R->getValueAsListOfDefs("RegTypes");
706 for (unsigned i = 0, e = TypeList.size(); i != e; ++i) {
707 Record *Type = TypeList[i];
708 if (!Type->isSubClassOf("ValueType"))
709 throw "RegTypes list member '" + Type->getName() +
710 "' does not derive from the ValueType class!";
711 VTs.push_back(getValueType(Type));
713 assert(!VTs.empty() && "RegisterClass must contain at least one ValueType!");
715 // Allocation order 0 is the full set. AltOrders provides others.
716 const SetTheory::RecVec *Elements = RegBank.getSets().expand(R);
717 ListInit *AltOrders = R->getValueAsListInit("AltOrders");
718 Orders.resize(1 + AltOrders->size());
720 // Default allocation order always contains all registers.
721 for (unsigned i = 0, e = Elements->size(); i != e; ++i) {
722 Orders[0].push_back((*Elements)[i]);
723 const CodeGenRegister *Reg = RegBank.getReg((*Elements)[i]);
725 TopoSigs.set(Reg->getTopoSig());
728 // Alternative allocation orders may be subsets.
729 SetTheory::RecSet Order;
730 for (unsigned i = 0, e = AltOrders->size(); i != e; ++i) {
731 RegBank.getSets().evaluate(AltOrders->getElement(i), Order);
732 Orders[1 + i].append(Order.begin(), Order.end());
733 // Verify that all altorder members are regclass members.
734 while (!Order.empty()) {
735 CodeGenRegister *Reg = RegBank.getReg(Order.back());
738 throw TGError(R->getLoc(), " AltOrder register " + Reg->getName() +
739 " is not a class member");
743 // Allow targets to override the size in bits of the RegisterClass.
744 unsigned Size = R->getValueAsInt("Size");
746 Namespace = R->getValueAsString("Namespace");
747 SpillSize = Size ? Size : EVT(VTs[0]).getSizeInBits();
748 SpillAlignment = R->getValueAsInt("Alignment");
749 CopyCost = R->getValueAsInt("CopyCost");
750 Allocatable = R->getValueAsBit("isAllocatable");
751 AltOrderSelect = R->getValueAsString("AltOrderSelect");
754 // Create an inferred register class that was missing from the .td files.
755 // Most properties will be inherited from the closest super-class after the
756 // class structure has been computed.
757 CodeGenRegisterClass::CodeGenRegisterClass(CodeGenRegBank &RegBank,
758 StringRef Name, Key Props)
759 : Members(*Props.Members),
762 TopoSigs(RegBank.getNumTopoSigs()),
764 SpillSize(Props.SpillSize),
765 SpillAlignment(Props.SpillAlignment),
768 for (CodeGenRegister::Set::iterator I = Members.begin(), E = Members.end();
770 TopoSigs.set((*I)->getTopoSig());
773 // Compute inherited propertied for a synthesized register class.
774 void CodeGenRegisterClass::inheritProperties(CodeGenRegBank &RegBank) {
775 assert(!getDef() && "Only synthesized classes can inherit properties");
776 assert(!SuperClasses.empty() && "Synthesized class without super class");
778 // The last super-class is the smallest one.
779 CodeGenRegisterClass &Super = *SuperClasses.back();
781 // Most properties are copied directly.
782 // Exceptions are members, size, and alignment
783 Namespace = Super.Namespace;
785 CopyCost = Super.CopyCost;
786 Allocatable = Super.Allocatable;
787 AltOrderSelect = Super.AltOrderSelect;
789 // Copy all allocation orders, filter out foreign registers from the larger
791 Orders.resize(Super.Orders.size());
792 for (unsigned i = 0, ie = Super.Orders.size(); i != ie; ++i)
793 for (unsigned j = 0, je = Super.Orders[i].size(); j != je; ++j)
794 if (contains(RegBank.getReg(Super.Orders[i][j])))
795 Orders[i].push_back(Super.Orders[i][j]);
798 bool CodeGenRegisterClass::contains(const CodeGenRegister *Reg) const {
799 return Members.count(Reg);
803 raw_ostream &operator<<(raw_ostream &OS, const CodeGenRegisterClass::Key &K) {
804 OS << "{ S=" << K.SpillSize << ", A=" << K.SpillAlignment;
805 for (CodeGenRegister::Set::const_iterator I = K.Members->begin(),
806 E = K.Members->end(); I != E; ++I)
807 OS << ", " << (*I)->getName();
812 // This is a simple lexicographical order that can be used to search for sets.
813 // It is not the same as the topological order provided by TopoOrderRC.
814 bool CodeGenRegisterClass::Key::
815 operator<(const CodeGenRegisterClass::Key &B) const {
816 assert(Members && B.Members);
817 if (*Members != *B.Members)
818 return *Members < *B.Members;
819 if (SpillSize != B.SpillSize)
820 return SpillSize < B.SpillSize;
821 return SpillAlignment < B.SpillAlignment;
824 // Returns true if RC is a strict subclass.
825 // RC is a sub-class of this class if it is a valid replacement for any
826 // instruction operand where a register of this classis required. It must
827 // satisfy these conditions:
829 // 1. All RC registers are also in this.
830 // 2. The RC spill size must not be smaller than our spill size.
831 // 3. RC spill alignment must be compatible with ours.
833 static bool testSubClass(const CodeGenRegisterClass *A,
834 const CodeGenRegisterClass *B) {
835 return A->SpillAlignment && B->SpillAlignment % A->SpillAlignment == 0 &&
836 A->SpillSize <= B->SpillSize &&
837 std::includes(A->getMembers().begin(), A->getMembers().end(),
838 B->getMembers().begin(), B->getMembers().end(),
839 CodeGenRegister::Less());
842 /// Sorting predicate for register classes. This provides a topological
843 /// ordering that arranges all register classes before their sub-classes.
845 /// Register classes with the same registers, spill size, and alignment form a
846 /// clique. They will be ordered alphabetically.
848 static int TopoOrderRC(const void *PA, const void *PB) {
849 const CodeGenRegisterClass *A = *(const CodeGenRegisterClass* const*)PA;
850 const CodeGenRegisterClass *B = *(const CodeGenRegisterClass* const*)PB;
854 // Order by ascending spill size.
855 if (A->SpillSize < B->SpillSize)
857 if (A->SpillSize > B->SpillSize)
860 // Order by ascending spill alignment.
861 if (A->SpillAlignment < B->SpillAlignment)
863 if (A->SpillAlignment > B->SpillAlignment)
866 // Order by descending set size. Note that the classes' allocation order may
867 // not have been computed yet. The Members set is always vaild.
868 if (A->getMembers().size() > B->getMembers().size())
870 if (A->getMembers().size() < B->getMembers().size())
873 // Finally order by name as a tie breaker.
874 return StringRef(A->getName()).compare(B->getName());
877 std::string CodeGenRegisterClass::getQualifiedName() const {
878 if (Namespace.empty())
881 return Namespace + "::" + getName();
884 // Compute sub-classes of all register classes.
885 // Assume the classes are ordered topologically.
886 void CodeGenRegisterClass::computeSubClasses(CodeGenRegBank &RegBank) {
887 ArrayRef<CodeGenRegisterClass*> RegClasses = RegBank.getRegClasses();
889 // Visit backwards so sub-classes are seen first.
890 for (unsigned rci = RegClasses.size(); rci; --rci) {
891 CodeGenRegisterClass &RC = *RegClasses[rci - 1];
892 RC.SubClasses.resize(RegClasses.size());
893 RC.SubClasses.set(RC.EnumValue);
895 // Normally, all subclasses have IDs >= rci, unless RC is part of a clique.
896 for (unsigned s = rci; s != RegClasses.size(); ++s) {
897 if (RC.SubClasses.test(s))
899 CodeGenRegisterClass *SubRC = RegClasses[s];
900 if (!testSubClass(&RC, SubRC))
902 // SubRC is a sub-class. Grap all its sub-classes so we won't have to
904 RC.SubClasses |= SubRC->SubClasses;
907 // Sweep up missed clique members. They will be immediately preceding RC.
908 for (unsigned s = rci - 1; s && testSubClass(&RC, RegClasses[s - 1]); --s)
909 RC.SubClasses.set(s - 1);
912 // Compute the SuperClasses lists from the SubClasses vectors.
913 for (unsigned rci = 0; rci != RegClasses.size(); ++rci) {
914 const BitVector &SC = RegClasses[rci]->getSubClasses();
915 for (int s = SC.find_first(); s >= 0; s = SC.find_next(s)) {
916 if (unsigned(s) == rci)
918 RegClasses[s]->SuperClasses.push_back(RegClasses[rci]);
922 // With the class hierarchy in place, let synthesized register classes inherit
923 // properties from their closest super-class. The iteration order here can
924 // propagate properties down multiple levels.
925 for (unsigned rci = 0; rci != RegClasses.size(); ++rci)
926 if (!RegClasses[rci]->getDef())
927 RegClasses[rci]->inheritProperties(RegBank);
931 CodeGenRegisterClass::getSuperRegClasses(CodeGenSubRegIndex *SubIdx,
932 BitVector &Out) const {
933 DenseMap<CodeGenSubRegIndex*,
934 SmallPtrSet<CodeGenRegisterClass*, 8> >::const_iterator
935 FindI = SuperRegClasses.find(SubIdx);
936 if (FindI == SuperRegClasses.end())
938 for (SmallPtrSet<CodeGenRegisterClass*, 8>::const_iterator I =
939 FindI->second.begin(), E = FindI->second.end(); I != E; ++I)
940 Out.set((*I)->EnumValue);
943 // Populate a unique sorted list of units from a register set.
944 void CodeGenRegisterClass::buildRegUnitSet(
945 std::vector<unsigned> &RegUnits) const {
946 std::vector<unsigned> TmpUnits;
947 for (RegUnitIterator UnitI(Members); UnitI.isValid(); ++UnitI)
948 TmpUnits.push_back(*UnitI);
949 std::sort(TmpUnits.begin(), TmpUnits.end());
950 std::unique_copy(TmpUnits.begin(), TmpUnits.end(),
951 std::back_inserter(RegUnits));
954 //===----------------------------------------------------------------------===//
956 //===----------------------------------------------------------------------===//
958 CodeGenRegBank::CodeGenRegBank(RecordKeeper &Records) {
959 // Configure register Sets to understand register classes and tuples.
960 Sets.addFieldExpander("RegisterClass", "MemberList");
961 Sets.addFieldExpander("CalleeSavedRegs", "SaveList");
962 Sets.addExpander("RegisterTuples", new TupleExpander());
964 // Read in the user-defined (named) sub-register indices.
965 // More indices will be synthesized later.
966 std::vector<Record*> SRIs = Records.getAllDerivedDefinitions("SubRegIndex");
967 std::sort(SRIs.begin(), SRIs.end(), LessRecord());
968 for (unsigned i = 0, e = SRIs.size(); i != e; ++i)
969 getSubRegIdx(SRIs[i]);
970 // Build composite maps from ComposedOf fields.
971 for (unsigned i = 0, e = SubRegIndices.size(); i != e; ++i)
972 SubRegIndices[i]->updateComponents(*this);
974 // Read in the register definitions.
975 std::vector<Record*> Regs = Records.getAllDerivedDefinitions("Register");
976 std::sort(Regs.begin(), Regs.end(), LessRecord());
977 Registers.reserve(Regs.size());
978 // Assign the enumeration values.
979 for (unsigned i = 0, e = Regs.size(); i != e; ++i)
982 // Expand tuples and number the new registers.
983 std::vector<Record*> Tups =
984 Records.getAllDerivedDefinitions("RegisterTuples");
985 for (unsigned i = 0, e = Tups.size(); i != e; ++i) {
986 const std::vector<Record*> *TupRegs = Sets.expand(Tups[i]);
987 for (unsigned j = 0, je = TupRegs->size(); j != je; ++j)
988 getReg((*TupRegs)[j]);
991 // Now all the registers are known. Build the object graph of explicit
992 // register-register references.
993 for (unsigned i = 0, e = Registers.size(); i != e; ++i)
994 Registers[i]->buildObjectGraph(*this);
996 // Precompute all sub-register maps.
997 // This will create Composite entries for all inferred sub-register indices.
998 for (unsigned i = 0, e = Registers.size(); i != e; ++i)
999 Registers[i]->computeSubRegs(*this);
1001 // Infer even more sub-registers by combining leading super-registers.
1002 for (unsigned i = 0, e = Registers.size(); i != e; ++i)
1003 if (Registers[i]->CoveredBySubRegs)
1004 Registers[i]->computeSecondarySubRegs(*this);
1006 // After the sub-register graph is complete, compute the topologically
1007 // ordered SuperRegs list.
1008 for (unsigned i = 0, e = Registers.size(); i != e; ++i)
1009 Registers[i]->computeSuperRegs(*this);
1011 // Native register units are associated with a leaf register. They've all been
1013 NumNativeRegUnits = RegUnits.size();
1015 // Read in register class definitions.
1016 std::vector<Record*> RCs = Records.getAllDerivedDefinitions("RegisterClass");
1018 throw std::string("No 'RegisterClass' subclasses defined!");
1020 // Allocate user-defined register classes.
1021 RegClasses.reserve(RCs.size());
1022 for (unsigned i = 0, e = RCs.size(); i != e; ++i)
1023 addToMaps(new CodeGenRegisterClass(*this, RCs[i]));
1025 // Infer missing classes to create a full algebra.
1026 computeInferredRegisterClasses();
1028 // Order register classes topologically and assign enum values.
1029 array_pod_sort(RegClasses.begin(), RegClasses.end(), TopoOrderRC);
1030 for (unsigned i = 0, e = RegClasses.size(); i != e; ++i)
1031 RegClasses[i]->EnumValue = i;
1032 CodeGenRegisterClass::computeSubClasses(*this);
1035 // Create a synthetic CodeGenSubRegIndex without a corresponding Record.
1037 CodeGenRegBank::createSubRegIndex(StringRef Name, StringRef Namespace) {
1038 CodeGenSubRegIndex *Idx = new CodeGenSubRegIndex(Name, Namespace,
1039 SubRegIndices.size() + 1);
1040 SubRegIndices.push_back(Idx);
1044 CodeGenSubRegIndex *CodeGenRegBank::getSubRegIdx(Record *Def) {
1045 CodeGenSubRegIndex *&Idx = Def2SubRegIdx[Def];
1048 Idx = new CodeGenSubRegIndex(Def, SubRegIndices.size() + 1);
1049 SubRegIndices.push_back(Idx);
1053 CodeGenRegister *CodeGenRegBank::getReg(Record *Def) {
1054 CodeGenRegister *&Reg = Def2Reg[Def];
1057 Reg = new CodeGenRegister(Def, Registers.size() + 1);
1058 Registers.push_back(Reg);
1062 void CodeGenRegBank::addToMaps(CodeGenRegisterClass *RC) {
1063 RegClasses.push_back(RC);
1065 if (Record *Def = RC->getDef())
1066 Def2RC.insert(std::make_pair(Def, RC));
1068 // Duplicate classes are rejected by insert().
1069 // That's OK, we only care about the properties handled by CGRC::Key.
1070 CodeGenRegisterClass::Key K(*RC);
1071 Key2RC.insert(std::make_pair(K, RC));
1074 // Create a synthetic sub-class if it is missing.
1075 CodeGenRegisterClass*
1076 CodeGenRegBank::getOrCreateSubClass(const CodeGenRegisterClass *RC,
1077 const CodeGenRegister::Set *Members,
1079 // Synthetic sub-class has the same size and alignment as RC.
1080 CodeGenRegisterClass::Key K(Members, RC->SpillSize, RC->SpillAlignment);
1081 RCKeyMap::const_iterator FoundI = Key2RC.find(K);
1082 if (FoundI != Key2RC.end())
1083 return FoundI->second;
1085 // Sub-class doesn't exist, create a new one.
1086 CodeGenRegisterClass *NewRC = new CodeGenRegisterClass(*this, Name, K);
1091 CodeGenRegisterClass *CodeGenRegBank::getRegClass(Record *Def) {
1092 if (CodeGenRegisterClass *RC = Def2RC[Def])
1095 throw TGError(Def->getLoc(), "Not a known RegisterClass!");
1099 CodeGenRegBank::getCompositeSubRegIndex(CodeGenSubRegIndex *A,
1100 CodeGenSubRegIndex *B) {
1101 // Look for an existing entry.
1102 CodeGenSubRegIndex *Comp = A->compose(B);
1106 // None exists, synthesize one.
1107 std::string Name = A->getName() + "_then_" + B->getName();
1108 Comp = createSubRegIndex(Name, A->getNamespace());
1109 A->addComposite(B, Comp);
1113 CodeGenSubRegIndex *CodeGenRegBank::
1114 getConcatSubRegIndex(const SmallVector<CodeGenSubRegIndex*, 8> &Parts) {
1115 assert(Parts.size() > 1 && "Need two parts to concatenate");
1117 // Look for an existing entry.
1118 CodeGenSubRegIndex *&Idx = ConcatIdx[Parts];
1122 // None exists, synthesize one.
1123 std::string Name = Parts.front()->getName();
1124 for (unsigned i = 1, e = Parts.size(); i != e; ++i) {
1126 Name += Parts[i]->getName();
1128 return Idx = createSubRegIndex(Name, Parts.front()->getNamespace());
1131 void CodeGenRegBank::computeComposites() {
1132 // Keep track of TopoSigs visited. We only need to visit each TopoSig once,
1133 // and many registers will share TopoSigs on regular architectures.
1134 BitVector TopoSigs(getNumTopoSigs());
1136 for (unsigned i = 0, e = Registers.size(); i != e; ++i) {
1137 CodeGenRegister *Reg1 = Registers[i];
1139 // Skip identical subreg structures already processed.
1140 if (TopoSigs.test(Reg1->getTopoSig()))
1142 TopoSigs.set(Reg1->getTopoSig());
1144 const CodeGenRegister::SubRegMap &SRM1 = Reg1->getSubRegs();
1145 for (CodeGenRegister::SubRegMap::const_iterator i1 = SRM1.begin(),
1146 e1 = SRM1.end(); i1 != e1; ++i1) {
1147 CodeGenSubRegIndex *Idx1 = i1->first;
1148 CodeGenRegister *Reg2 = i1->second;
1149 // Ignore identity compositions.
1152 const CodeGenRegister::SubRegMap &SRM2 = Reg2->getSubRegs();
1153 // Try composing Idx1 with another SubRegIndex.
1154 for (CodeGenRegister::SubRegMap::const_iterator i2 = SRM2.begin(),
1155 e2 = SRM2.end(); i2 != e2; ++i2) {
1156 CodeGenSubRegIndex *Idx2 = i2->first;
1157 CodeGenRegister *Reg3 = i2->second;
1158 // Ignore identity compositions.
1161 // OK Reg1:IdxPair == Reg3. Find the index with Reg:Idx == Reg3.
1162 CodeGenSubRegIndex *Idx3 = Reg1->getSubRegIndex(Reg3);
1163 assert(Idx3 && "Sub-register doesn't have an index");
1165 // Conflicting composition? Emit a warning but allow it.
1166 if (CodeGenSubRegIndex *Prev = Idx1->addComposite(Idx2, Idx3))
1167 PrintWarning(Twine("SubRegIndex ") + Idx1->getQualifiedName() +
1168 " and " + Idx2->getQualifiedName() +
1169 " compose ambiguously as " + Prev->getQualifiedName() +
1170 " or " + Idx3->getQualifiedName());
1176 // Compute lane masks. This is similar to register units, but at the
1177 // sub-register index level. Each bit in the lane mask is like a register unit
1178 // class, and two lane masks will have a bit in common if two sub-register
1179 // indices overlap in some register.
1181 // Conservatively share a lane mask bit if two sub-register indices overlap in
1182 // some registers, but not in others. That shouldn't happen a lot.
1183 void CodeGenRegBank::computeSubRegIndexLaneMasks() {
1184 // First assign individual bits to all the leaf indices.
1186 for (unsigned i = 0, e = SubRegIndices.size(); i != e; ++i) {
1187 CodeGenSubRegIndex *Idx = SubRegIndices[i];
1188 if (Idx->getComposites().empty()) {
1189 Idx->LaneMask = 1u << Bit;
1190 // Share bit 31 in the unlikely case there are more than 32 leafs.
1191 if (Bit < 31) ++Bit;
1197 // FIXME: What if ad-hoc aliasing introduces overlaps that aren't represented
1198 // by the sub-register graph? This doesn't occur in any known targets.
1200 // Inherit lanes from composites.
1201 for (unsigned i = 0, e = SubRegIndices.size(); i != e; ++i)
1202 SubRegIndices[i]->computeLaneMask();
1206 // UberRegSet is a helper class for computeRegUnitWeights. Each UberRegSet is
1207 // the transitive closure of the union of overlapping register
1208 // classes. Together, the UberRegSets form a partition of the registers. If we
1209 // consider overlapping register classes to be connected, then each UberRegSet
1210 // is a set of connected components.
1212 // An UberRegSet will likely be a horizontal slice of register names of
1213 // the same width. Nontrivial subregisters should then be in a separate
1214 // UberRegSet. But this property isn't required for valid computation of
1215 // register unit weights.
1217 // A Weight field caches the max per-register unit weight in each UberRegSet.
1219 // A set of SingularDeterminants flags single units of some register in this set
1220 // for which the unit weight equals the set weight. These units should not have
1221 // their weight increased.
1223 CodeGenRegister::Set Regs;
1225 CodeGenRegister::RegUnitList SingularDeterminants;
1227 UberRegSet(): Weight(0) {}
1231 // Partition registers into UberRegSets, where each set is the transitive
1232 // closure of the union of overlapping register classes.
1234 // UberRegSets[0] is a special non-allocatable set.
1235 static void computeUberSets(std::vector<UberRegSet> &UberSets,
1236 std::vector<UberRegSet*> &RegSets,
1237 CodeGenRegBank &RegBank) {
1239 const std::vector<CodeGenRegister*> &Registers = RegBank.getRegisters();
1241 // The Register EnumValue is one greater than its index into Registers.
1242 assert(Registers.size() == Registers[Registers.size()-1]->EnumValue &&
1243 "register enum value mismatch");
1245 // For simplicitly make the SetID the same as EnumValue.
1246 IntEqClasses UberSetIDs(Registers.size()+1);
1247 std::set<unsigned> AllocatableRegs;
1248 for (unsigned i = 0, e = RegBank.getRegClasses().size(); i != e; ++i) {
1250 CodeGenRegisterClass *RegClass = RegBank.getRegClasses()[i];
1251 if (!RegClass->Allocatable)
1254 const CodeGenRegister::Set &Regs = RegClass->getMembers();
1258 unsigned USetID = UberSetIDs.findLeader((*Regs.begin())->EnumValue);
1259 assert(USetID && "register number 0 is invalid");
1261 AllocatableRegs.insert((*Regs.begin())->EnumValue);
1262 for (CodeGenRegister::Set::const_iterator I = llvm::next(Regs.begin()),
1263 E = Regs.end(); I != E; ++I) {
1264 AllocatableRegs.insert((*I)->EnumValue);
1265 UberSetIDs.join(USetID, (*I)->EnumValue);
1268 // Combine non-allocatable regs.
1269 for (unsigned i = 0, e = Registers.size(); i != e; ++i) {
1270 unsigned RegNum = Registers[i]->EnumValue;
1271 if (AllocatableRegs.count(RegNum))
1274 UberSetIDs.join(0, RegNum);
1276 UberSetIDs.compress();
1278 // Make the first UberSet a special unallocatable set.
1279 unsigned ZeroID = UberSetIDs[0];
1281 // Insert Registers into the UberSets formed by union-find.
1282 // Do not resize after this.
1283 UberSets.resize(UberSetIDs.getNumClasses());
1284 for (unsigned i = 0, e = Registers.size(); i != e; ++i) {
1285 const CodeGenRegister *Reg = Registers[i];
1286 unsigned USetID = UberSetIDs[Reg->EnumValue];
1289 else if (USetID == ZeroID)
1292 UberRegSet *USet = &UberSets[USetID];
1293 USet->Regs.insert(Reg);
1298 // Recompute each UberSet weight after changing unit weights.
1299 static void computeUberWeights(std::vector<UberRegSet> &UberSets,
1300 CodeGenRegBank &RegBank) {
1301 // Skip the first unallocatable set.
1302 for (std::vector<UberRegSet>::iterator I = llvm::next(UberSets.begin()),
1303 E = UberSets.end(); I != E; ++I) {
1305 // Initialize all unit weights in this set, and remember the max units/reg.
1306 const CodeGenRegister *Reg = 0;
1307 unsigned MaxWeight = 0, Weight = 0;
1308 for (RegUnitIterator UnitI(I->Regs); UnitI.isValid(); ++UnitI) {
1309 if (Reg != UnitI.getReg()) {
1310 if (Weight > MaxWeight)
1312 Reg = UnitI.getReg();
1315 unsigned UWeight = RegBank.getRegUnit(*UnitI).Weight;
1318 RegBank.increaseRegUnitWeight(*UnitI, UWeight);
1322 if (Weight > MaxWeight)
1325 // Update the set weight.
1326 I->Weight = MaxWeight;
1328 // Find singular determinants.
1329 for (CodeGenRegister::Set::iterator RegI = I->Regs.begin(),
1330 RegE = I->Regs.end(); RegI != RegE; ++RegI) {
1331 if ((*RegI)->getRegUnits().size() == 1
1332 && (*RegI)->getWeight(RegBank) == I->Weight)
1333 mergeRegUnits(I->SingularDeterminants, (*RegI)->getRegUnits());
1338 // normalizeWeight is a computeRegUnitWeights helper that adjusts the weight of
1339 // a register and its subregisters so that they have the same weight as their
1340 // UberSet. Self-recursion processes the subregister tree in postorder so
1341 // subregisters are normalized first.
1344 // - creates new adopted register units
1345 // - causes superregisters to inherit adopted units
1346 // - increases the weight of "singular" units
1347 // - induces recomputation of UberWeights.
1348 static bool normalizeWeight(CodeGenRegister *Reg,
1349 std::vector<UberRegSet> &UberSets,
1350 std::vector<UberRegSet*> &RegSets,
1351 std::set<unsigned> &NormalRegs,
1352 CodeGenRegister::RegUnitList &NormalUnits,
1353 CodeGenRegBank &RegBank) {
1354 bool Changed = false;
1355 if (!NormalRegs.insert(Reg->EnumValue).second)
1358 const CodeGenRegister::SubRegMap &SRM = Reg->getSubRegs();
1359 for (CodeGenRegister::SubRegMap::const_iterator SRI = SRM.begin(),
1360 SRE = SRM.end(); SRI != SRE; ++SRI) {
1361 if (SRI->second == Reg)
1362 continue; // self-cycles happen
1364 Changed |= normalizeWeight(SRI->second, UberSets, RegSets,
1365 NormalRegs, NormalUnits, RegBank);
1367 // Postorder register normalization.
1369 // Inherit register units newly adopted by subregisters.
1370 if (Reg->inheritRegUnits(RegBank))
1371 computeUberWeights(UberSets, RegBank);
1373 // Check if this register is too skinny for its UberRegSet.
1374 UberRegSet *UberSet = RegSets[RegBank.getRegIndex(Reg)];
1376 unsigned RegWeight = Reg->getWeight(RegBank);
1377 if (UberSet->Weight > RegWeight) {
1378 // A register unit's weight can be adjusted only if it is the singular unit
1379 // for this register, has not been used to normalize a subregister's set,
1380 // and has not already been used to singularly determine this UberRegSet.
1381 unsigned AdjustUnit = Reg->getRegUnits().front();
1382 if (Reg->getRegUnits().size() != 1
1383 || hasRegUnit(NormalUnits, AdjustUnit)
1384 || hasRegUnit(UberSet->SingularDeterminants, AdjustUnit)) {
1385 // We don't have an adjustable unit, so adopt a new one.
1386 AdjustUnit = RegBank.newRegUnit(UberSet->Weight - RegWeight);
1387 Reg->adoptRegUnit(AdjustUnit);
1388 // Adopting a unit does not immediately require recomputing set weights.
1391 // Adjust the existing single unit.
1392 RegBank.increaseRegUnitWeight(AdjustUnit, UberSet->Weight - RegWeight);
1393 // The unit may be shared among sets and registers within this set.
1394 computeUberWeights(UberSets, RegBank);
1399 // Mark these units normalized so superregisters can't change their weights.
1400 mergeRegUnits(NormalUnits, Reg->getRegUnits());
1405 // Compute a weight for each register unit created during getSubRegs.
1407 // The goal is that two registers in the same class will have the same weight,
1408 // where each register's weight is defined as sum of its units' weights.
1409 void CodeGenRegBank::computeRegUnitWeights() {
1410 std::vector<UberRegSet> UberSets;
1411 std::vector<UberRegSet*> RegSets(Registers.size());
1412 computeUberSets(UberSets, RegSets, *this);
1413 // UberSets and RegSets are now immutable.
1415 computeUberWeights(UberSets, *this);
1417 // Iterate over each Register, normalizing the unit weights until reaching
1419 unsigned NumIters = 0;
1420 for (bool Changed = true; Changed; ++NumIters) {
1421 assert(NumIters <= NumNativeRegUnits && "Runaway register unit weights");
1423 for (unsigned i = 0, e = Registers.size(); i != e; ++i) {
1424 CodeGenRegister::RegUnitList NormalUnits;
1425 std::set<unsigned> NormalRegs;
1426 Changed |= normalizeWeight(Registers[i], UberSets, RegSets,
1427 NormalRegs, NormalUnits, *this);
1432 // Find a set in UniqueSets with the same elements as Set.
1433 // Return an iterator into UniqueSets.
1434 static std::vector<RegUnitSet>::const_iterator
1435 findRegUnitSet(const std::vector<RegUnitSet> &UniqueSets,
1436 const RegUnitSet &Set) {
1437 std::vector<RegUnitSet>::const_iterator
1438 I = UniqueSets.begin(), E = UniqueSets.end();
1440 if (I->Units == Set.Units)
1446 // Return true if the RUSubSet is a subset of RUSuperSet.
1447 static bool isRegUnitSubSet(const std::vector<unsigned> &RUSubSet,
1448 const std::vector<unsigned> &RUSuperSet) {
1449 return std::includes(RUSuperSet.begin(), RUSuperSet.end(),
1450 RUSubSet.begin(), RUSubSet.end());
1453 // Iteratively prune unit sets.
1454 void CodeGenRegBank::pruneUnitSets() {
1455 assert(RegClassUnitSets.empty() && "this invalidates RegClassUnitSets");
1457 // Form an equivalence class of UnitSets with no significant difference.
1458 std::vector<unsigned> SuperSetIDs;
1459 for (unsigned SubIdx = 0, EndIdx = RegUnitSets.size();
1460 SubIdx != EndIdx; ++SubIdx) {
1461 const RegUnitSet &SubSet = RegUnitSets[SubIdx];
1462 unsigned SuperIdx = 0;
1463 for (; SuperIdx != EndIdx; ++SuperIdx) {
1464 if (SuperIdx == SubIdx)
1467 const RegUnitSet &SuperSet = RegUnitSets[SuperIdx];
1468 if (isRegUnitSubSet(SubSet.Units, SuperSet.Units)
1469 && (SubSet.Units.size() + 3 > SuperSet.Units.size())) {
1473 if (SuperIdx == EndIdx)
1474 SuperSetIDs.push_back(SubIdx);
1476 // Populate PrunedUnitSets with each equivalence class's superset.
1477 std::vector<RegUnitSet> PrunedUnitSets(SuperSetIDs.size());
1478 for (unsigned i = 0, e = SuperSetIDs.size(); i != e; ++i) {
1479 unsigned SuperIdx = SuperSetIDs[i];
1480 PrunedUnitSets[i].Name = RegUnitSets[SuperIdx].Name;
1481 PrunedUnitSets[i].Units.swap(RegUnitSets[SuperIdx].Units);
1483 RegUnitSets.swap(PrunedUnitSets);
1486 // Create a RegUnitSet for each RegClass that contains all units in the class
1487 // including adopted units that are necessary to model register pressure. Then
1488 // iteratively compute RegUnitSets such that the union of any two overlapping
1489 // RegUnitSets is repreresented.
1491 // RegisterInfoEmitter will map each RegClass to its RegUnitClass and any
1492 // RegUnitSet that is a superset of that RegUnitClass.
1493 void CodeGenRegBank::computeRegUnitSets() {
1495 // Compute a unique RegUnitSet for each RegClass.
1496 const ArrayRef<CodeGenRegisterClass*> &RegClasses = getRegClasses();
1497 unsigned NumRegClasses = RegClasses.size();
1498 for (unsigned RCIdx = 0, RCEnd = NumRegClasses; RCIdx != RCEnd; ++RCIdx) {
1499 if (!RegClasses[RCIdx]->Allocatable)
1502 // Speculatively grow the RegUnitSets to hold the new set.
1503 RegUnitSets.resize(RegUnitSets.size() + 1);
1504 RegUnitSets.back().Name = RegClasses[RCIdx]->getName();
1506 // Compute a sorted list of units in this class.
1507 RegClasses[RCIdx]->buildRegUnitSet(RegUnitSets.back().Units);
1509 // Find an existing RegUnitSet.
1510 std::vector<RegUnitSet>::const_iterator SetI =
1511 findRegUnitSet(RegUnitSets, RegUnitSets.back());
1512 if (SetI != llvm::prior(RegUnitSets.end()))
1513 RegUnitSets.pop_back();
1516 // Iteratively prune unit sets.
1519 // Iterate over all unit sets, including new ones added by this loop.
1520 unsigned NumRegUnitSubSets = RegUnitSets.size();
1521 for (unsigned Idx = 0, EndIdx = RegUnitSets.size(); Idx != EndIdx; ++Idx) {
1522 // In theory, this is combinatorial. In practice, it needs to be bounded
1523 // by a small number of sets for regpressure to be efficient.
1524 // If the assert is hit, we need to implement pruning.
1525 assert(Idx < (2*NumRegUnitSubSets) && "runaway unit set inference");
1527 // Compare new sets with all original classes.
1528 for (unsigned SearchIdx = (Idx >= NumRegUnitSubSets) ? 0 : Idx+1;
1529 SearchIdx != EndIdx; ++SearchIdx) {
1530 std::set<unsigned> Intersection;
1531 std::set_intersection(RegUnitSets[Idx].Units.begin(),
1532 RegUnitSets[Idx].Units.end(),
1533 RegUnitSets[SearchIdx].Units.begin(),
1534 RegUnitSets[SearchIdx].Units.end(),
1535 std::inserter(Intersection, Intersection.begin()));
1536 if (Intersection.empty())
1539 // Speculatively grow the RegUnitSets to hold the new set.
1540 RegUnitSets.resize(RegUnitSets.size() + 1);
1541 RegUnitSets.back().Name =
1542 RegUnitSets[Idx].Name + "+" + RegUnitSets[SearchIdx].Name;
1544 std::set_union(RegUnitSets[Idx].Units.begin(),
1545 RegUnitSets[Idx].Units.end(),
1546 RegUnitSets[SearchIdx].Units.begin(),
1547 RegUnitSets[SearchIdx].Units.end(),
1548 std::inserter(RegUnitSets.back().Units,
1549 RegUnitSets.back().Units.begin()));
1551 // Find an existing RegUnitSet, or add the union to the unique sets.
1552 std::vector<RegUnitSet>::const_iterator SetI =
1553 findRegUnitSet(RegUnitSets, RegUnitSets.back());
1554 if (SetI != llvm::prior(RegUnitSets.end()))
1555 RegUnitSets.pop_back();
1559 // Iteratively prune unit sets after inferring supersets.
1562 // For each register class, list the UnitSets that are supersets.
1563 RegClassUnitSets.resize(NumRegClasses);
1564 for (unsigned RCIdx = 0, RCEnd = NumRegClasses; RCIdx != RCEnd; ++RCIdx) {
1565 if (!RegClasses[RCIdx]->Allocatable)
1568 // Recompute the sorted list of units in this class.
1569 std::vector<unsigned> RegUnits;
1570 RegClasses[RCIdx]->buildRegUnitSet(RegUnits);
1572 // Don't increase pressure for unallocatable regclasses.
1573 if (RegUnits.empty())
1576 // Find all supersets.
1577 for (unsigned USIdx = 0, USEnd = RegUnitSets.size();
1578 USIdx != USEnd; ++USIdx) {
1579 if (isRegUnitSubSet(RegUnits, RegUnitSets[USIdx].Units))
1580 RegClassUnitSets[RCIdx].push_back(USIdx);
1582 assert(!RegClassUnitSets[RCIdx].empty() && "missing unit set for regclass");
1586 void CodeGenRegBank::computeDerivedInfo() {
1587 computeComposites();
1588 computeSubRegIndexLaneMasks();
1590 // Compute a weight for each register unit created during getSubRegs.
1591 // This may create adopted register units (with unit # >= NumNativeRegUnits).
1592 computeRegUnitWeights();
1594 // Compute a unique set of RegUnitSets. One for each RegClass and inferred
1595 // supersets for the union of overlapping sets.
1596 computeRegUnitSets();
1600 // Synthesize missing register class intersections.
1602 // Make sure that sub-classes of RC exists such that getCommonSubClass(RC, X)
1603 // returns a maximal register class for all X.
1605 void CodeGenRegBank::inferCommonSubClass(CodeGenRegisterClass *RC) {
1606 for (unsigned rci = 0, rce = RegClasses.size(); rci != rce; ++rci) {
1607 CodeGenRegisterClass *RC1 = RC;
1608 CodeGenRegisterClass *RC2 = RegClasses[rci];
1612 // Compute the set intersection of RC1 and RC2.
1613 const CodeGenRegister::Set &Memb1 = RC1->getMembers();
1614 const CodeGenRegister::Set &Memb2 = RC2->getMembers();
1615 CodeGenRegister::Set Intersection;
1616 std::set_intersection(Memb1.begin(), Memb1.end(),
1617 Memb2.begin(), Memb2.end(),
1618 std::inserter(Intersection, Intersection.begin()),
1619 CodeGenRegister::Less());
1621 // Skip disjoint class pairs.
1622 if (Intersection.empty())
1625 // If RC1 and RC2 have different spill sizes or alignments, use the
1626 // larger size for sub-classing. If they are equal, prefer RC1.
1627 if (RC2->SpillSize > RC1->SpillSize ||
1628 (RC2->SpillSize == RC1->SpillSize &&
1629 RC2->SpillAlignment > RC1->SpillAlignment))
1630 std::swap(RC1, RC2);
1632 getOrCreateSubClass(RC1, &Intersection,
1633 RC1->getName() + "_and_" + RC2->getName());
1638 // Synthesize missing sub-classes for getSubClassWithSubReg().
1640 // Make sure that the set of registers in RC with a given SubIdx sub-register
1641 // form a register class. Update RC->SubClassWithSubReg.
1643 void CodeGenRegBank::inferSubClassWithSubReg(CodeGenRegisterClass *RC) {
1644 // Map SubRegIndex to set of registers in RC supporting that SubRegIndex.
1645 typedef std::map<CodeGenSubRegIndex*, CodeGenRegister::Set,
1646 CodeGenSubRegIndex::Less> SubReg2SetMap;
1648 // Compute the set of registers supporting each SubRegIndex.
1649 SubReg2SetMap SRSets;
1650 for (CodeGenRegister::Set::const_iterator RI = RC->getMembers().begin(),
1651 RE = RC->getMembers().end(); RI != RE; ++RI) {
1652 const CodeGenRegister::SubRegMap &SRM = (*RI)->getSubRegs();
1653 for (CodeGenRegister::SubRegMap::const_iterator I = SRM.begin(),
1654 E = SRM.end(); I != E; ++I)
1655 SRSets[I->first].insert(*RI);
1658 // Find matching classes for all SRSets entries. Iterate in SubRegIndex
1659 // numerical order to visit synthetic indices last.
1660 for (unsigned sri = 0, sre = SubRegIndices.size(); sri != sre; ++sri) {
1661 CodeGenSubRegIndex *SubIdx = SubRegIndices[sri];
1662 SubReg2SetMap::const_iterator I = SRSets.find(SubIdx);
1663 // Unsupported SubRegIndex. Skip it.
1664 if (I == SRSets.end())
1666 // In most cases, all RC registers support the SubRegIndex.
1667 if (I->second.size() == RC->getMembers().size()) {
1668 RC->setSubClassWithSubReg(SubIdx, RC);
1671 // This is a real subset. See if we have a matching class.
1672 CodeGenRegisterClass *SubRC =
1673 getOrCreateSubClass(RC, &I->second,
1674 RC->getName() + "_with_" + I->first->getName());
1675 RC->setSubClassWithSubReg(SubIdx, SubRC);
1680 // Synthesize missing sub-classes of RC for getMatchingSuperRegClass().
1682 // Create sub-classes of RC such that getMatchingSuperRegClass(RC, SubIdx, X)
1683 // has a maximal result for any SubIdx and any X >= FirstSubRegRC.
1686 void CodeGenRegBank::inferMatchingSuperRegClass(CodeGenRegisterClass *RC,
1687 unsigned FirstSubRegRC) {
1688 SmallVector<std::pair<const CodeGenRegister*,
1689 const CodeGenRegister*>, 16> SSPairs;
1690 BitVector TopoSigs(getNumTopoSigs());
1692 // Iterate in SubRegIndex numerical order to visit synthetic indices last.
1693 for (unsigned sri = 0, sre = SubRegIndices.size(); sri != sre; ++sri) {
1694 CodeGenSubRegIndex *SubIdx = SubRegIndices[sri];
1695 // Skip indexes that aren't fully supported by RC's registers. This was
1696 // computed by inferSubClassWithSubReg() above which should have been
1698 if (RC->getSubClassWithSubReg(SubIdx) != RC)
1701 // Build list of (Super, Sub) pairs for this SubIdx.
1704 for (CodeGenRegister::Set::const_iterator RI = RC->getMembers().begin(),
1705 RE = RC->getMembers().end(); RI != RE; ++RI) {
1706 const CodeGenRegister *Super = *RI;
1707 const CodeGenRegister *Sub = Super->getSubRegs().find(SubIdx)->second;
1708 assert(Sub && "Missing sub-register");
1709 SSPairs.push_back(std::make_pair(Super, Sub));
1710 TopoSigs.set(Sub->getTopoSig());
1713 // Iterate over sub-register class candidates. Ignore classes created by
1714 // this loop. They will never be useful.
1715 for (unsigned rci = FirstSubRegRC, rce = RegClasses.size(); rci != rce;
1717 CodeGenRegisterClass *SubRC = RegClasses[rci];
1718 // Topological shortcut: SubRC members have the wrong shape.
1719 if (!TopoSigs.anyCommon(SubRC->getTopoSigs()))
1721 // Compute the subset of RC that maps into SubRC.
1722 CodeGenRegister::Set SubSet;
1723 for (unsigned i = 0, e = SSPairs.size(); i != e; ++i)
1724 if (SubRC->contains(SSPairs[i].second))
1725 SubSet.insert(SSPairs[i].first);
1728 // RC injects completely into SubRC.
1729 if (SubSet.size() == SSPairs.size()) {
1730 SubRC->addSuperRegClass(SubIdx, RC);
1733 // Only a subset of RC maps into SubRC. Make sure it is represented by a
1735 getOrCreateSubClass(RC, &SubSet, RC->getName() +
1736 "_with_" + SubIdx->getName() +
1737 "_in_" + SubRC->getName());
1744 // Infer missing register classes.
1746 void CodeGenRegBank::computeInferredRegisterClasses() {
1747 // When this function is called, the register classes have not been sorted
1748 // and assigned EnumValues yet. That means getSubClasses(),
1749 // getSuperClasses(), and hasSubClass() functions are defunct.
1750 unsigned FirstNewRC = RegClasses.size();
1752 // Visit all register classes, including the ones being added by the loop.
1753 for (unsigned rci = 0; rci != RegClasses.size(); ++rci) {
1754 CodeGenRegisterClass *RC = RegClasses[rci];
1756 // Synthesize answers for getSubClassWithSubReg().
1757 inferSubClassWithSubReg(RC);
1759 // Synthesize answers for getCommonSubClass().
1760 inferCommonSubClass(RC);
1762 // Synthesize answers for getMatchingSuperRegClass().
1763 inferMatchingSuperRegClass(RC);
1765 // New register classes are created while this loop is running, and we need
1766 // to visit all of them. I particular, inferMatchingSuperRegClass needs
1767 // to match old super-register classes with sub-register classes created
1768 // after inferMatchingSuperRegClass was called. At this point,
1769 // inferMatchingSuperRegClass has checked SuperRC = [0..rci] with SubRC =
1770 // [0..FirstNewRC). We need to cover SubRC = [FirstNewRC..rci].
1771 if (rci + 1 == FirstNewRC) {
1772 unsigned NextNewRC = RegClasses.size();
1773 for (unsigned rci2 = 0; rci2 != FirstNewRC; ++rci2)
1774 inferMatchingSuperRegClass(RegClasses[rci2], FirstNewRC);
1775 FirstNewRC = NextNewRC;
1780 /// getRegisterClassForRegister - Find the register class that contains the
1781 /// specified physical register. If the register is not in a register class,
1782 /// return null. If the register is in multiple classes, and the classes have a
1783 /// superset-subset relationship and the same set of types, return the
1784 /// superclass. Otherwise return null.
1785 const CodeGenRegisterClass*
1786 CodeGenRegBank::getRegClassForRegister(Record *R) {
1787 const CodeGenRegister *Reg = getReg(R);
1788 ArrayRef<CodeGenRegisterClass*> RCs = getRegClasses();
1789 const CodeGenRegisterClass *FoundRC = 0;
1790 for (unsigned i = 0, e = RCs.size(); i != e; ++i) {
1791 const CodeGenRegisterClass &RC = *RCs[i];
1792 if (!RC.contains(Reg))
1795 // If this is the first class that contains the register,
1796 // make a note of it and go on to the next class.
1802 // If a register's classes have different types, return null.
1803 if (RC.getValueTypes() != FoundRC->getValueTypes())
1806 // Check to see if the previously found class that contains
1807 // the register is a subclass of the current class. If so,
1808 // prefer the superclass.
1809 if (RC.hasSubClass(FoundRC)) {
1814 // Check to see if the previously found class that contains
1815 // the register is a superclass of the current class. If so,
1816 // prefer the superclass.
1817 if (FoundRC->hasSubClass(&RC))
1820 // Multiple classes, and neither is a superclass of the other.
1827 BitVector CodeGenRegBank::computeCoveredRegisters(ArrayRef<Record*> Regs) {
1828 SetVector<const CodeGenRegister*> Set;
1830 // First add Regs with all sub-registers.
1831 for (unsigned i = 0, e = Regs.size(); i != e; ++i) {
1832 CodeGenRegister *Reg = getReg(Regs[i]);
1833 if (Set.insert(Reg))
1834 // Reg is new, add all sub-registers.
1835 // The pre-ordering is not important here.
1836 Reg->addSubRegsPreOrder(Set, *this);
1839 // Second, find all super-registers that are completely covered by the set.
1840 for (unsigned i = 0; i != Set.size(); ++i) {
1841 const CodeGenRegister::SuperRegList &SR = Set[i]->getSuperRegs();
1842 for (unsigned j = 0, e = SR.size(); j != e; ++j) {
1843 const CodeGenRegister *Super = SR[j];
1844 if (!Super->CoveredBySubRegs || Set.count(Super))
1846 // This new super-register is covered by its sub-registers.
1847 bool AllSubsInSet = true;
1848 const CodeGenRegister::SubRegMap &SRM = Super->getSubRegs();
1849 for (CodeGenRegister::SubRegMap::const_iterator I = SRM.begin(),
1850 E = SRM.end(); I != E; ++I)
1851 if (!Set.count(I->second)) {
1852 AllSubsInSet = false;
1855 // All sub-registers in Set, add Super as well.
1856 // We will visit Super later to recheck its super-registers.
1862 // Convert to BitVector.
1863 BitVector BV(Registers.size() + 1);
1864 for (unsigned i = 0, e = Set.size(); i != e; ++i)
1865 BV.set(Set[i]->EnumValue);