1 //===- CodeGenInstruction.cpp - CodeGen Instruction Class Wrapper ---------===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file implements the CodeGenInstruction class.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "CodeGenInstruction.h"
15 #include "CodeGenTarget.h"
16 #include "llvm/ADT/STLExtras.h"
17 #include "llvm/ADT/StringExtras.h"
18 #include "llvm/ADT/StringMap.h"
19 #include "llvm/TableGen/Error.h"
20 #include "llvm/TableGen/Record.h"
21 #include <set>
22 using namespace llvm;
23 
24 //===----------------------------------------------------------------------===//
25 // CGIOperandList Implementation
26 //===----------------------------------------------------------------------===//
27 
CGIOperandList(Record * R)28 CGIOperandList::CGIOperandList(Record *R) : TheDef(R) {
29   isPredicable = false;
30   hasOptionalDef = false;
31   isVariadic = false;
32 
33   DagInit *OutDI = R->getValueAsDag("OutOperandList");
34 
35   if (DefInit *Init = dyn_cast<DefInit>(OutDI->getOperator())) {
36     if (Init->getDef()->getName() != "outs")
37       PrintFatalError(R->getName() + ": invalid def name for output list: use 'outs'");
38   } else
39     PrintFatalError(R->getName() + ": invalid output list: use 'outs'");
40 
41   NumDefs = OutDI->getNumArgs();
42 
43   DagInit *InDI = R->getValueAsDag("InOperandList");
44   if (DefInit *Init = dyn_cast<DefInit>(InDI->getOperator())) {
45     if (Init->getDef()->getName() != "ins")
46       PrintFatalError(R->getName() + ": invalid def name for input list: use 'ins'");
47   } else
48     PrintFatalError(R->getName() + ": invalid input list: use 'ins'");
49 
50   unsigned MIOperandNo = 0;
51   std::set<std::string> OperandNames;
52   for (unsigned i = 0, e = InDI->getNumArgs()+OutDI->getNumArgs(); i != e; ++i){
53     Init *ArgInit;
54     std::string ArgName;
55     if (i < NumDefs) {
56       ArgInit = OutDI->getArg(i);
57       ArgName = OutDI->getArgName(i);
58     } else {
59       ArgInit = InDI->getArg(i-NumDefs);
60       ArgName = InDI->getArgName(i-NumDefs);
61     }
62 
63     DefInit *Arg = dyn_cast<DefInit>(ArgInit);
64     if (!Arg)
65       PrintFatalError("Illegal operand for the '" + R->getName() + "' instruction!");
66 
67     Record *Rec = Arg->getDef();
68     std::string PrintMethod = "printOperand";
69     std::string EncoderMethod;
70     std::string OperandType = "OPERAND_UNKNOWN";
71     std::string OperandNamespace = "MCOI";
72     unsigned NumOps = 1;
73     DagInit *MIOpInfo = nullptr;
74     if (Rec->isSubClassOf("RegisterOperand")) {
75       PrintMethod = Rec->getValueAsString("PrintMethod");
76       OperandType = Rec->getValueAsString("OperandType");
77       OperandNamespace = Rec->getValueAsString("OperandNamespace");
78     } else if (Rec->isSubClassOf("Operand")) {
79       PrintMethod = Rec->getValueAsString("PrintMethod");
80       OperandType = Rec->getValueAsString("OperandType");
81       // If there is an explicit encoder method, use it.
82       EncoderMethod = Rec->getValueAsString("EncoderMethod");
83       MIOpInfo = Rec->getValueAsDag("MIOperandInfo");
84 
85       // Verify that MIOpInfo has an 'ops' root value.
86       if (!isa<DefInit>(MIOpInfo->getOperator()) ||
87           cast<DefInit>(MIOpInfo->getOperator())->getDef()->getName() != "ops")
88         PrintFatalError("Bad value for MIOperandInfo in operand '" + Rec->getName() +
89           "'\n");
90 
91       // If we have MIOpInfo, then we have #operands equal to number of entries
92       // in MIOperandInfo.
93       if (unsigned NumArgs = MIOpInfo->getNumArgs())
94         NumOps = NumArgs;
95 
96       if (Rec->isSubClassOf("PredicateOp"))
97         isPredicable = true;
98       else if (Rec->isSubClassOf("OptionalDefOperand"))
99         hasOptionalDef = true;
100     } else if (Rec->getName() == "variable_ops") {
101       isVariadic = true;
102       continue;
103     } else if (Rec->isSubClassOf("RegisterClass")) {
104       OperandType = "OPERAND_REGISTER";
105     } else if (!Rec->isSubClassOf("PointerLikeRegClass") &&
106                !Rec->isSubClassOf("unknown_class"))
107       PrintFatalError("Unknown operand class '" + Rec->getName() +
108         "' in '" + R->getName() + "' instruction!");
109 
110     // Check that the operand has a name and that it's unique.
111     if (ArgName.empty())
112       PrintFatalError("In instruction '" + R->getName() + "', operand #" +
113                       Twine(i) + " has no name!");
114     if (!OperandNames.insert(ArgName).second)
115       PrintFatalError("In instruction '" + R->getName() + "', operand #" +
116                       Twine(i) + " has the same name as a previous operand!");
117 
118     OperandList.push_back(OperandInfo(Rec, ArgName, PrintMethod, EncoderMethod,
119                                       OperandNamespace + "::" + OperandType,
120 				      MIOperandNo, NumOps, MIOpInfo));
121     MIOperandNo += NumOps;
122   }
123 
124 
125   // Make sure the constraints list for each operand is large enough to hold
126   // constraint info, even if none is present.
127   for (unsigned i = 0, e = OperandList.size(); i != e; ++i)
128     OperandList[i].Constraints.resize(OperandList[i].MINumOperands);
129 }
130 
131 
132 /// getOperandNamed - Return the index of the operand with the specified
133 /// non-empty name.  If the instruction does not have an operand with the
134 /// specified name, abort.
135 ///
getOperandNamed(StringRef Name) const136 unsigned CGIOperandList::getOperandNamed(StringRef Name) const {
137   unsigned OpIdx;
138   if (hasOperandNamed(Name, OpIdx)) return OpIdx;
139   PrintFatalError("'" + TheDef->getName() +
140                   "' does not have an operand named '$" + Name + "'!");
141 }
142 
143 /// hasOperandNamed - Query whether the instruction has an operand of the
144 /// given name. If so, return true and set OpIdx to the index of the
145 /// operand. Otherwise, return false.
hasOperandNamed(StringRef Name,unsigned & OpIdx) const146 bool CGIOperandList::hasOperandNamed(StringRef Name, unsigned &OpIdx) const {
147   assert(!Name.empty() && "Cannot search for operand with no name!");
148   for (unsigned i = 0, e = OperandList.size(); i != e; ++i)
149     if (OperandList[i].Name == Name) {
150       OpIdx = i;
151       return true;
152     }
153   return false;
154 }
155 
156 std::pair<unsigned,unsigned>
ParseOperandName(const std::string & Op,bool AllowWholeOp)157 CGIOperandList::ParseOperandName(const std::string &Op, bool AllowWholeOp) {
158   if (Op.empty() || Op[0] != '$')
159     PrintFatalError(TheDef->getName() + ": Illegal operand name: '" + Op + "'");
160 
161   std::string OpName = Op.substr(1);
162   std::string SubOpName;
163 
164   // Check to see if this is $foo.bar.
165   std::string::size_type DotIdx = OpName.find_first_of(".");
166   if (DotIdx != std::string::npos) {
167     SubOpName = OpName.substr(DotIdx+1);
168     if (SubOpName.empty())
169       PrintFatalError(TheDef->getName() + ": illegal empty suboperand name in '" +Op +"'");
170     OpName = OpName.substr(0, DotIdx);
171   }
172 
173   unsigned OpIdx = getOperandNamed(OpName);
174 
175   if (SubOpName.empty()) {  // If no suboperand name was specified:
176     // If one was needed, throw.
177     if (OperandList[OpIdx].MINumOperands > 1 && !AllowWholeOp &&
178         SubOpName.empty())
179       PrintFatalError(TheDef->getName() + ": Illegal to refer to"
180         " whole operand part of complex operand '" + Op + "'");
181 
182     // Otherwise, return the operand.
183     return std::make_pair(OpIdx, 0U);
184   }
185 
186   // Find the suboperand number involved.
187   DagInit *MIOpInfo = OperandList[OpIdx].MIOperandInfo;
188   if (!MIOpInfo)
189     PrintFatalError(TheDef->getName() + ": unknown suboperand name in '" + Op + "'");
190 
191   // Find the operand with the right name.
192   for (unsigned i = 0, e = MIOpInfo->getNumArgs(); i != e; ++i)
193     if (MIOpInfo->getArgName(i) == SubOpName)
194       return std::make_pair(OpIdx, i);
195 
196   // Otherwise, didn't find it!
197   PrintFatalError(TheDef->getName() + ": unknown suboperand name in '" + Op + "'");
198   return std::make_pair(0U, 0U);
199 }
200 
ParseConstraint(const std::string & CStr,CGIOperandList & Ops)201 static void ParseConstraint(const std::string &CStr, CGIOperandList &Ops) {
202   // EARLY_CLOBBER: @early $reg
203   std::string::size_type wpos = CStr.find_first_of(" \t");
204   std::string::size_type start = CStr.find_first_not_of(" \t");
205   std::string Tok = CStr.substr(start, wpos - start);
206   if (Tok == "@earlyclobber") {
207     std::string Name = CStr.substr(wpos+1);
208     wpos = Name.find_first_not_of(" \t");
209     if (wpos == std::string::npos)
210       PrintFatalError("Illegal format for @earlyclobber constraint: '" + CStr + "'");
211     Name = Name.substr(wpos);
212     std::pair<unsigned,unsigned> Op = Ops.ParseOperandName(Name, false);
213 
214     // Build the string for the operand
215     if (!Ops[Op.first].Constraints[Op.second].isNone())
216       PrintFatalError("Operand '" + Name + "' cannot have multiple constraints!");
217     Ops[Op.first].Constraints[Op.second] =
218     CGIOperandList::ConstraintInfo::getEarlyClobber();
219     return;
220   }
221 
222   // Only other constraint is "TIED_TO" for now.
223   std::string::size_type pos = CStr.find_first_of('=');
224   assert(pos != std::string::npos && "Unrecognized constraint");
225   start = CStr.find_first_not_of(" \t");
226   std::string Name = CStr.substr(start, pos - start);
227 
228   // TIED_TO: $src1 = $dst
229   wpos = Name.find_first_of(" \t");
230   if (wpos == std::string::npos)
231     PrintFatalError("Illegal format for tied-to constraint: '" + CStr + "'");
232   std::string DestOpName = Name.substr(0, wpos);
233   std::pair<unsigned,unsigned> DestOp = Ops.ParseOperandName(DestOpName, false);
234 
235   Name = CStr.substr(pos+1);
236   wpos = Name.find_first_not_of(" \t");
237   if (wpos == std::string::npos)
238     PrintFatalError("Illegal format for tied-to constraint: '" + CStr + "'");
239 
240   std::string SrcOpName = Name.substr(wpos);
241   std::pair<unsigned,unsigned> SrcOp = Ops.ParseOperandName(SrcOpName, false);
242   if (SrcOp > DestOp) {
243     std::swap(SrcOp, DestOp);
244     std::swap(SrcOpName, DestOpName);
245   }
246 
247   unsigned FlatOpNo = Ops.getFlattenedOperandNumber(SrcOp);
248 
249   if (!Ops[DestOp.first].Constraints[DestOp.second].isNone())
250     PrintFatalError("Operand '" + DestOpName +
251       "' cannot have multiple constraints!");
252   Ops[DestOp.first].Constraints[DestOp.second] =
253     CGIOperandList::ConstraintInfo::getTied(FlatOpNo);
254 }
255 
ParseConstraints(const std::string & CStr,CGIOperandList & Ops)256 static void ParseConstraints(const std::string &CStr, CGIOperandList &Ops) {
257   if (CStr.empty()) return;
258 
259   const std::string delims(",");
260   std::string::size_type bidx, eidx;
261 
262   bidx = CStr.find_first_not_of(delims);
263   while (bidx != std::string::npos) {
264     eidx = CStr.find_first_of(delims, bidx);
265     if (eidx == std::string::npos)
266       eidx = CStr.length();
267 
268     ParseConstraint(CStr.substr(bidx, eidx - bidx), Ops);
269     bidx = CStr.find_first_not_of(delims, eidx);
270   }
271 }
272 
ProcessDisableEncoding(std::string DisableEncoding)273 void CGIOperandList::ProcessDisableEncoding(std::string DisableEncoding) {
274   while (1) {
275     std::pair<StringRef, StringRef> P = getToken(DisableEncoding, " ,\t");
276     std::string OpName = P.first;
277     DisableEncoding = P.second;
278     if (OpName.empty()) break;
279 
280     // Figure out which operand this is.
281     std::pair<unsigned,unsigned> Op = ParseOperandName(OpName, false);
282 
283     // Mark the operand as not-to-be encoded.
284     if (Op.second >= OperandList[Op.first].DoNotEncode.size())
285       OperandList[Op.first].DoNotEncode.resize(Op.second+1);
286     OperandList[Op.first].DoNotEncode[Op.second] = true;
287   }
288 
289 }
290 
291 //===----------------------------------------------------------------------===//
292 // CodeGenInstruction Implementation
293 //===----------------------------------------------------------------------===//
294 
CodeGenInstruction(Record * R)295 CodeGenInstruction::CodeGenInstruction(Record *R)
296   : TheDef(R), Operands(R), InferredFrom(nullptr) {
297   Namespace = R->getValueAsString("Namespace");
298   AsmString = R->getValueAsString("AsmString");
299 
300   isReturn     = R->getValueAsBit("isReturn");
301   isBranch     = R->getValueAsBit("isBranch");
302   isIndirectBranch = R->getValueAsBit("isIndirectBranch");
303   isCompare    = R->getValueAsBit("isCompare");
304   isMoveImm    = R->getValueAsBit("isMoveImm");
305   isBitcast    = R->getValueAsBit("isBitcast");
306   isSelect     = R->getValueAsBit("isSelect");
307   isBarrier    = R->getValueAsBit("isBarrier");
308   isCall       = R->getValueAsBit("isCall");
309   canFoldAsLoad = R->getValueAsBit("canFoldAsLoad");
310   isPredicable = Operands.isPredicable || R->getValueAsBit("isPredicable");
311   isConvertibleToThreeAddress = R->getValueAsBit("isConvertibleToThreeAddress");
312   isCommutable = R->getValueAsBit("isCommutable");
313   isTerminator = R->getValueAsBit("isTerminator");
314   isReMaterializable = R->getValueAsBit("isReMaterializable");
315   hasDelaySlot = R->getValueAsBit("hasDelaySlot");
316   usesCustomInserter = R->getValueAsBit("usesCustomInserter");
317   hasPostISelHook = R->getValueAsBit("hasPostISelHook");
318   hasCtrlDep   = R->getValueAsBit("hasCtrlDep");
319   isNotDuplicable = R->getValueAsBit("isNotDuplicable");
320   isRegSequence = R->getValueAsBit("isRegSequence");
321   isExtractSubreg = R->getValueAsBit("isExtractSubreg");
322   isInsertSubreg = R->getValueAsBit("isInsertSubreg");
323 
324   bool Unset;
325   mayLoad      = R->getValueAsBitOrUnset("mayLoad", Unset);
326   mayLoad_Unset = Unset;
327   mayStore     = R->getValueAsBitOrUnset("mayStore", Unset);
328   mayStore_Unset = Unset;
329   hasSideEffects = R->getValueAsBitOrUnset("hasSideEffects", Unset);
330   hasSideEffects_Unset = Unset;
331 
332   isAsCheapAsAMove = R->getValueAsBit("isAsCheapAsAMove");
333   hasExtraSrcRegAllocReq = R->getValueAsBit("hasExtraSrcRegAllocReq");
334   hasExtraDefRegAllocReq = R->getValueAsBit("hasExtraDefRegAllocReq");
335   isCodeGenOnly = R->getValueAsBit("isCodeGenOnly");
336   isPseudo = R->getValueAsBit("isPseudo");
337   ImplicitDefs = R->getValueAsListOfDefs("Defs");
338   ImplicitUses = R->getValueAsListOfDefs("Uses");
339 
340   // Parse Constraints.
341   ParseConstraints(R->getValueAsString("Constraints"), Operands);
342 
343   // Parse the DisableEncoding field.
344   Operands.ProcessDisableEncoding(R->getValueAsString("DisableEncoding"));
345 
346   // First check for a ComplexDeprecationPredicate.
347   if (R->getValue("ComplexDeprecationPredicate")) {
348     HasComplexDeprecationPredicate = true;
349     DeprecatedReason = R->getValueAsString("ComplexDeprecationPredicate");
350   } else if (RecordVal *Dep = R->getValue("DeprecatedFeatureMask")) {
351     // Check if we have a Subtarget feature mask.
352     HasComplexDeprecationPredicate = false;
353     DeprecatedReason = Dep->getValue()->getAsString();
354   } else {
355     // This instruction isn't deprecated.
356     HasComplexDeprecationPredicate = false;
357     DeprecatedReason = "";
358   }
359 }
360 
361 /// HasOneImplicitDefWithKnownVT - If the instruction has at least one
362 /// implicit def and it has a known VT, return the VT, otherwise return
363 /// MVT::Other.
364 MVT::SimpleValueType CodeGenInstruction::
HasOneImplicitDefWithKnownVT(const CodeGenTarget & TargetInfo) const365 HasOneImplicitDefWithKnownVT(const CodeGenTarget &TargetInfo) const {
366   if (ImplicitDefs.empty()) return MVT::Other;
367 
368   // Check to see if the first implicit def has a resolvable type.
369   Record *FirstImplicitDef = ImplicitDefs[0];
370   assert(FirstImplicitDef->isSubClassOf("Register"));
371   const std::vector<MVT::SimpleValueType> &RegVTs =
372     TargetInfo.getRegisterVTs(FirstImplicitDef);
373   if (RegVTs.size() == 1)
374     return RegVTs[0];
375   return MVT::Other;
376 }
377 
378 
379 /// FlattenAsmStringVariants - Flatten the specified AsmString to only
380 /// include text from the specified variant, returning the new string.
381 std::string CodeGenInstruction::
FlattenAsmStringVariants(StringRef Cur,unsigned Variant)382 FlattenAsmStringVariants(StringRef Cur, unsigned Variant) {
383   std::string Res = "";
384 
385   for (;;) {
386     // Find the start of the next variant string.
387     size_t VariantsStart = 0;
388     for (size_t e = Cur.size(); VariantsStart != e; ++VariantsStart)
389       if (Cur[VariantsStart] == '{' &&
390           (VariantsStart == 0 || (Cur[VariantsStart-1] != '$' &&
391                                   Cur[VariantsStart-1] != '\\')))
392         break;
393 
394     // Add the prefix to the result.
395     Res += Cur.slice(0, VariantsStart);
396     if (VariantsStart == Cur.size())
397       break;
398 
399     ++VariantsStart; // Skip the '{'.
400 
401     // Scan to the end of the variants string.
402     size_t VariantsEnd = VariantsStart;
403     unsigned NestedBraces = 1;
404     for (size_t e = Cur.size(); VariantsEnd != e; ++VariantsEnd) {
405       if (Cur[VariantsEnd] == '}' && Cur[VariantsEnd-1] != '\\') {
406         if (--NestedBraces == 0)
407           break;
408       } else if (Cur[VariantsEnd] == '{')
409         ++NestedBraces;
410     }
411 
412     // Select the Nth variant (or empty).
413     StringRef Selection = Cur.slice(VariantsStart, VariantsEnd);
414     for (unsigned i = 0; i != Variant; ++i)
415       Selection = Selection.split('|').second;
416     Res += Selection.split('|').first;
417 
418     assert(VariantsEnd != Cur.size() &&
419            "Unterminated variants in assembly string!");
420     Cur = Cur.substr(VariantsEnd + 1);
421   }
422 
423   return Res;
424 }
425 
426 
427 //===----------------------------------------------------------------------===//
428 /// CodeGenInstAlias Implementation
429 //===----------------------------------------------------------------------===//
430 
431 /// tryAliasOpMatch - This is a helper function for the CodeGenInstAlias
432 /// constructor.  It checks if an argument in an InstAlias pattern matches
433 /// the corresponding operand of the instruction.  It returns true on a
434 /// successful match, with ResOp set to the result operand to be used.
tryAliasOpMatch(DagInit * Result,unsigned AliasOpNo,Record * InstOpRec,bool hasSubOps,ArrayRef<SMLoc> Loc,CodeGenTarget & T,ResultOperand & ResOp)435 bool CodeGenInstAlias::tryAliasOpMatch(DagInit *Result, unsigned AliasOpNo,
436                                        Record *InstOpRec, bool hasSubOps,
437                                        ArrayRef<SMLoc> Loc, CodeGenTarget &T,
438                                        ResultOperand &ResOp) {
439   Init *Arg = Result->getArg(AliasOpNo);
440   DefInit *ADI = dyn_cast<DefInit>(Arg);
441   Record *ResultRecord = ADI ? ADI->getDef() : nullptr;
442 
443   if (ADI && ADI->getDef() == InstOpRec) {
444     // If the operand is a record, it must have a name, and the record type
445     // must match up with the instruction's argument type.
446     if (Result->getArgName(AliasOpNo).empty())
447       PrintFatalError(Loc, "result argument #" + Twine(AliasOpNo) +
448                            " must have a name!");
449     ResOp = ResultOperand(Result->getArgName(AliasOpNo), ResultRecord);
450     return true;
451   }
452 
453   // For register operands, the source register class can be a subclass
454   // of the instruction register class, not just an exact match.
455   if (InstOpRec->isSubClassOf("RegisterOperand"))
456     InstOpRec = InstOpRec->getValueAsDef("RegClass");
457 
458   if (ADI && ADI->getDef()->isSubClassOf("RegisterOperand"))
459     ADI = ADI->getDef()->getValueAsDef("RegClass")->getDefInit();
460 
461   if (ADI && ADI->getDef()->isSubClassOf("RegisterClass")) {
462     if (!InstOpRec->isSubClassOf("RegisterClass"))
463       return false;
464     if (!T.getRegisterClass(InstOpRec)
465               .hasSubClass(&T.getRegisterClass(ADI->getDef())))
466       return false;
467     ResOp = ResultOperand(Result->getArgName(AliasOpNo), ResultRecord);
468     return true;
469   }
470 
471   // Handle explicit registers.
472   if (ADI && ADI->getDef()->isSubClassOf("Register")) {
473     if (InstOpRec->isSubClassOf("OptionalDefOperand")) {
474       DagInit *DI = InstOpRec->getValueAsDag("MIOperandInfo");
475       // The operand info should only have a single (register) entry. We
476       // want the register class of it.
477       InstOpRec = cast<DefInit>(DI->getArg(0))->getDef();
478     }
479 
480     if (!InstOpRec->isSubClassOf("RegisterClass"))
481       return false;
482 
483     if (!T.getRegisterClass(InstOpRec)
484         .contains(T.getRegBank().getReg(ADI->getDef())))
485       PrintFatalError(Loc, "fixed register " + ADI->getDef()->getName() +
486                       " is not a member of the " + InstOpRec->getName() +
487                       " register class!");
488 
489     if (!Result->getArgName(AliasOpNo).empty())
490       PrintFatalError(Loc, "result fixed register argument must "
491                       "not have a name!");
492 
493     ResOp = ResultOperand(ResultRecord);
494     return true;
495   }
496 
497   // Handle "zero_reg" for optional def operands.
498   if (ADI && ADI->getDef()->getName() == "zero_reg") {
499 
500     // Check if this is an optional def.
501     // Tied operands where the source is a sub-operand of a complex operand
502     // need to represent both operands in the alias destination instruction.
503     // Allow zero_reg for the tied portion. This can and should go away once
504     // the MC representation of things doesn't use tied operands at all.
505     //if (!InstOpRec->isSubClassOf("OptionalDefOperand"))
506     //  throw TGError(Loc, "reg0 used for result that is not an "
507     //                "OptionalDefOperand!");
508 
509     ResOp = ResultOperand(static_cast<Record*>(nullptr));
510     return true;
511   }
512 
513   // Literal integers.
514   if (IntInit *II = dyn_cast<IntInit>(Arg)) {
515     if (hasSubOps || !InstOpRec->isSubClassOf("Operand"))
516       return false;
517     // Integer arguments can't have names.
518     if (!Result->getArgName(AliasOpNo).empty())
519       PrintFatalError(Loc, "result argument #" + Twine(AliasOpNo) +
520                       " must not have a name!");
521     ResOp = ResultOperand(II->getValue());
522     return true;
523   }
524 
525   // Bits<n> (also used for 0bxx literals)
526   if (BitsInit *BI = dyn_cast<BitsInit>(Arg)) {
527     if (hasSubOps || !InstOpRec->isSubClassOf("Operand"))
528       return false;
529     if (!BI->isComplete())
530       return false;
531     // Convert the bits init to an integer and use that for the result.
532     IntInit *II =
533       dyn_cast_or_null<IntInit>(BI->convertInitializerTo(IntRecTy::get()));
534     if (!II)
535       return false;
536     ResOp = ResultOperand(II->getValue());
537     return true;
538   }
539 
540   // If both are Operands with the same MVT, allow the conversion. It's
541   // up to the user to make sure the values are appropriate, just like
542   // for isel Pat's.
543   if (InstOpRec->isSubClassOf("Operand") && ADI &&
544       ADI->getDef()->isSubClassOf("Operand")) {
545     // FIXME: What other attributes should we check here? Identical
546     // MIOperandInfo perhaps?
547     if (InstOpRec->getValueInit("Type") != ADI->getDef()->getValueInit("Type"))
548       return false;
549     ResOp = ResultOperand(Result->getArgName(AliasOpNo), ADI->getDef());
550     return true;
551   }
552 
553   return false;
554 }
555 
getMINumOperands() const556 unsigned CodeGenInstAlias::ResultOperand::getMINumOperands() const {
557   if (!isRecord())
558     return 1;
559 
560   Record *Rec = getRecord();
561   if (!Rec->isSubClassOf("Operand"))
562     return 1;
563 
564   DagInit *MIOpInfo = Rec->getValueAsDag("MIOperandInfo");
565   if (MIOpInfo->getNumArgs() == 0) {
566     // Unspecified, so it defaults to 1
567     return 1;
568   }
569 
570   return MIOpInfo->getNumArgs();
571 }
572 
CodeGenInstAlias(Record * R,unsigned Variant,CodeGenTarget & T)573 CodeGenInstAlias::CodeGenInstAlias(Record *R, unsigned Variant,
574                                    CodeGenTarget &T)
575     : TheDef(R) {
576   Result = R->getValueAsDag("ResultInst");
577   AsmString = R->getValueAsString("AsmString");
578   AsmString = CodeGenInstruction::FlattenAsmStringVariants(AsmString, Variant);
579 
580 
581   // Verify that the root of the result is an instruction.
582   DefInit *DI = dyn_cast<DefInit>(Result->getOperator());
583   if (!DI || !DI->getDef()->isSubClassOf("Instruction"))
584     PrintFatalError(R->getLoc(),
585                     "result of inst alias should be an instruction");
586 
587   ResultInst = &T.getInstruction(DI->getDef());
588 
589   // NameClass - If argument names are repeated, we need to verify they have
590   // the same class.
591   StringMap<Record*> NameClass;
592   for (unsigned i = 0, e = Result->getNumArgs(); i != e; ++i) {
593     DefInit *ADI = dyn_cast<DefInit>(Result->getArg(i));
594     if (!ADI || Result->getArgName(i).empty())
595       continue;
596     // Verify we don't have something like: (someinst GR16:$foo, GR32:$foo)
597     // $foo can exist multiple times in the result list, but it must have the
598     // same type.
599     Record *&Entry = NameClass[Result->getArgName(i)];
600     if (Entry && Entry != ADI->getDef())
601       PrintFatalError(R->getLoc(), "result value $" + Result->getArgName(i) +
602                       " is both " + Entry->getName() + " and " +
603                       ADI->getDef()->getName() + "!");
604     Entry = ADI->getDef();
605   }
606 
607   // Decode and validate the arguments of the result.
608   unsigned AliasOpNo = 0;
609   for (unsigned i = 0, e = ResultInst->Operands.size(); i != e; ++i) {
610 
611     // Tied registers don't have an entry in the result dag unless they're part
612     // of a complex operand, in which case we include them anyways, as we
613     // don't have any other way to specify the whole operand.
614     if (ResultInst->Operands[i].MINumOperands == 1 &&
615         ResultInst->Operands[i].getTiedRegister() != -1)
616       continue;
617 
618     if (AliasOpNo >= Result->getNumArgs())
619       PrintFatalError(R->getLoc(), "not enough arguments for instruction!");
620 
621     Record *InstOpRec = ResultInst->Operands[i].Rec;
622     unsigned NumSubOps = ResultInst->Operands[i].MINumOperands;
623     ResultOperand ResOp(static_cast<int64_t>(0));
624     if (tryAliasOpMatch(Result, AliasOpNo, InstOpRec, (NumSubOps > 1),
625                         R->getLoc(), T, ResOp)) {
626       // If this is a simple operand, or a complex operand with a custom match
627       // class, then we can match is verbatim.
628       if (NumSubOps == 1 ||
629           (InstOpRec->getValue("ParserMatchClass") &&
630            InstOpRec->getValueAsDef("ParserMatchClass")
631              ->getValueAsString("Name") != "Imm")) {
632         ResultOperands.push_back(ResOp);
633         ResultInstOperandIndex.push_back(std::make_pair(i, -1));
634         ++AliasOpNo;
635 
636       // Otherwise, we need to match each of the suboperands individually.
637       } else {
638          DagInit *MIOI = ResultInst->Operands[i].MIOperandInfo;
639          for (unsigned SubOp = 0; SubOp != NumSubOps; ++SubOp) {
640           Record *SubRec = cast<DefInit>(MIOI->getArg(SubOp))->getDef();
641 
642           // Take care to instantiate each of the suboperands with the correct
643           // nomenclature: $foo.bar
644           ResultOperands.push_back(
645               ResultOperand(Result->getArgName(AliasOpNo) + "." +
646                             MIOI->getArgName(SubOp), SubRec));
647           ResultInstOperandIndex.push_back(std::make_pair(i, SubOp));
648          }
649          ++AliasOpNo;
650       }
651       continue;
652     }
653 
654     // If the argument did not match the instruction operand, and the operand
655     // is composed of multiple suboperands, try matching the suboperands.
656     if (NumSubOps > 1) {
657       DagInit *MIOI = ResultInst->Operands[i].MIOperandInfo;
658       for (unsigned SubOp = 0; SubOp != NumSubOps; ++SubOp) {
659         if (AliasOpNo >= Result->getNumArgs())
660           PrintFatalError(R->getLoc(), "not enough arguments for instruction!");
661         Record *SubRec = cast<DefInit>(MIOI->getArg(SubOp))->getDef();
662         if (tryAliasOpMatch(Result, AliasOpNo, SubRec, false,
663                             R->getLoc(), T, ResOp)) {
664           ResultOperands.push_back(ResOp);
665           ResultInstOperandIndex.push_back(std::make_pair(i, SubOp));
666           ++AliasOpNo;
667         } else {
668           PrintFatalError(R->getLoc(), "result argument #" + Twine(AliasOpNo) +
669                         " does not match instruction operand class " +
670                         (SubOp == 0 ? InstOpRec->getName() :SubRec->getName()));
671         }
672       }
673       continue;
674     }
675     PrintFatalError(R->getLoc(), "result argument #" + Twine(AliasOpNo) +
676                     " does not match instruction operand class " +
677                     InstOpRec->getName());
678   }
679 
680   if (AliasOpNo != Result->getNumArgs())
681     PrintFatalError(R->getLoc(), "too many operands for instruction!");
682 }
683