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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   unsigned e = InDI->getNumArgs() + OutDI->getNumArgs();
53   OperandList.reserve(e);
54   for (unsigned i = 0; i != e; ++i){
55     Init *ArgInit;
56     std::string ArgName;
57     if (i < NumDefs) {
58       ArgInit = OutDI->getArg(i);
59       ArgName = OutDI->getArgName(i);
60     } else {
61       ArgInit = InDI->getArg(i-NumDefs);
62       ArgName = InDI->getArgName(i-NumDefs);
63     }
64 
65     DefInit *Arg = dyn_cast<DefInit>(ArgInit);
66     if (!Arg)
67       PrintFatalError("Illegal operand for the '" + R->getName() + "' instruction!");
68 
69     Record *Rec = Arg->getDef();
70     std::string PrintMethod = "printOperand";
71     std::string EncoderMethod;
72     std::string OperandType = "OPERAND_UNKNOWN";
73     std::string OperandNamespace = "MCOI";
74     unsigned NumOps = 1;
75     DagInit *MIOpInfo = nullptr;
76     if (Rec->isSubClassOf("RegisterOperand")) {
77       PrintMethod = Rec->getValueAsString("PrintMethod");
78       OperandType = Rec->getValueAsString("OperandType");
79       OperandNamespace = Rec->getValueAsString("OperandNamespace");
80     } else if (Rec->isSubClassOf("Operand")) {
81       PrintMethod = Rec->getValueAsString("PrintMethod");
82       OperandType = Rec->getValueAsString("OperandType");
83       OperandNamespace = Rec->getValueAsString("OperandNamespace");
84       // If there is an explicit encoder method, use it.
85       EncoderMethod = Rec->getValueAsString("EncoderMethod");
86       MIOpInfo = Rec->getValueAsDag("MIOperandInfo");
87 
88       // Verify that MIOpInfo has an 'ops' root value.
89       if (!isa<DefInit>(MIOpInfo->getOperator()) ||
90           cast<DefInit>(MIOpInfo->getOperator())->getDef()->getName() != "ops")
91         PrintFatalError("Bad value for MIOperandInfo in operand '" + Rec->getName() +
92           "'\n");
93 
94       // If we have MIOpInfo, then we have #operands equal to number of entries
95       // in MIOperandInfo.
96       if (unsigned NumArgs = MIOpInfo->getNumArgs())
97         NumOps = NumArgs;
98 
99       if (Rec->isSubClassOf("PredicateOp"))
100         isPredicable = true;
101       else if (Rec->isSubClassOf("OptionalDefOperand"))
102         hasOptionalDef = true;
103     } else if (Rec->getName() == "variable_ops") {
104       isVariadic = true;
105       continue;
106     } else if (Rec->isSubClassOf("RegisterClass")) {
107       OperandType = "OPERAND_REGISTER";
108     } else if (!Rec->isSubClassOf("PointerLikeRegClass") &&
109                !Rec->isSubClassOf("unknown_class"))
110       PrintFatalError("Unknown operand class '" + Rec->getName() +
111         "' in '" + R->getName() + "' instruction!");
112 
113     // Check that the operand has a name and that it's unique.
114     if (ArgName.empty())
115       PrintFatalError("In instruction '" + R->getName() + "', operand #" +
116                       Twine(i) + " has no name!");
117     if (!OperandNames.insert(ArgName).second)
118       PrintFatalError("In instruction '" + R->getName() + "', operand #" +
119                       Twine(i) + " has the same name as a previous operand!");
120 
121     OperandList.emplace_back(Rec, ArgName, PrintMethod, EncoderMethod,
122                              OperandNamespace + "::" + OperandType, MIOperandNo,
123                              NumOps, MIOpInfo);
124     MIOperandNo += NumOps;
125   }
126 
127 
128   // Make sure the constraints list for each operand is large enough to hold
129   // constraint info, even if none is present.
130   for (unsigned i = 0, e = OperandList.size(); i != e; ++i)
131     OperandList[i].Constraints.resize(OperandList[i].MINumOperands);
132 }
133 
134 
135 /// getOperandNamed - Return the index of the operand with the specified
136 /// non-empty name.  If the instruction does not have an operand with the
137 /// specified name, abort.
138 ///
getOperandNamed(StringRef Name) const139 unsigned CGIOperandList::getOperandNamed(StringRef Name) const {
140   unsigned OpIdx;
141   if (hasOperandNamed(Name, OpIdx)) return OpIdx;
142   PrintFatalError("'" + TheDef->getName() +
143                   "' does not have an operand named '$" + Name + "'!");
144 }
145 
146 /// hasOperandNamed - Query whether the instruction has an operand of the
147 /// given name. If so, return true and set OpIdx to the index of the
148 /// operand. Otherwise, return false.
hasOperandNamed(StringRef Name,unsigned & OpIdx) const149 bool CGIOperandList::hasOperandNamed(StringRef Name, unsigned &OpIdx) const {
150   assert(!Name.empty() && "Cannot search for operand with no name!");
151   for (unsigned i = 0, e = OperandList.size(); i != e; ++i)
152     if (OperandList[i].Name == Name) {
153       OpIdx = i;
154       return true;
155     }
156   return false;
157 }
158 
159 std::pair<unsigned,unsigned>
ParseOperandName(const std::string & Op,bool AllowWholeOp)160 CGIOperandList::ParseOperandName(const std::string &Op, bool AllowWholeOp) {
161   if (Op.empty() || Op[0] != '$')
162     PrintFatalError(TheDef->getName() + ": Illegal operand name: '" + Op + "'");
163 
164   std::string OpName = Op.substr(1);
165   std::string SubOpName;
166 
167   // Check to see if this is $foo.bar.
168   std::string::size_type DotIdx = OpName.find_first_of(".");
169   if (DotIdx != std::string::npos) {
170     SubOpName = OpName.substr(DotIdx+1);
171     if (SubOpName.empty())
172       PrintFatalError(TheDef->getName() + ": illegal empty suboperand name in '" +Op +"'");
173     OpName = OpName.substr(0, DotIdx);
174   }
175 
176   unsigned OpIdx = getOperandNamed(OpName);
177 
178   if (SubOpName.empty()) {  // If no suboperand name was specified:
179     // If one was needed, throw.
180     if (OperandList[OpIdx].MINumOperands > 1 && !AllowWholeOp &&
181         SubOpName.empty())
182       PrintFatalError(TheDef->getName() + ": Illegal to refer to"
183         " whole operand part of complex operand '" + Op + "'");
184 
185     // Otherwise, return the operand.
186     return std::make_pair(OpIdx, 0U);
187   }
188 
189   // Find the suboperand number involved.
190   DagInit *MIOpInfo = OperandList[OpIdx].MIOperandInfo;
191   if (!MIOpInfo)
192     PrintFatalError(TheDef->getName() + ": unknown suboperand name in '" + Op + "'");
193 
194   // Find the operand with the right name.
195   for (unsigned i = 0, e = MIOpInfo->getNumArgs(); i != e; ++i)
196     if (MIOpInfo->getArgName(i) == SubOpName)
197       return std::make_pair(OpIdx, i);
198 
199   // Otherwise, didn't find it!
200   PrintFatalError(TheDef->getName() + ": unknown suboperand name in '" + Op + "'");
201   return std::make_pair(0U, 0U);
202 }
203 
ParseConstraint(const std::string & CStr,CGIOperandList & Ops)204 static void ParseConstraint(const std::string &CStr, CGIOperandList &Ops) {
205   // EARLY_CLOBBER: @early $reg
206   std::string::size_type wpos = CStr.find_first_of(" \t");
207   std::string::size_type start = CStr.find_first_not_of(" \t");
208   std::string Tok = CStr.substr(start, wpos - start);
209   if (Tok == "@earlyclobber") {
210     std::string Name = CStr.substr(wpos+1);
211     wpos = Name.find_first_not_of(" \t");
212     if (wpos == std::string::npos)
213       PrintFatalError("Illegal format for @earlyclobber constraint: '" + CStr + "'");
214     Name = Name.substr(wpos);
215     std::pair<unsigned,unsigned> Op = Ops.ParseOperandName(Name, false);
216 
217     // Build the string for the operand
218     if (!Ops[Op.first].Constraints[Op.second].isNone())
219       PrintFatalError("Operand '" + Name + "' cannot have multiple constraints!");
220     Ops[Op.first].Constraints[Op.second] =
221     CGIOperandList::ConstraintInfo::getEarlyClobber();
222     return;
223   }
224 
225   // Only other constraint is "TIED_TO" for now.
226   std::string::size_type pos = CStr.find_first_of('=');
227   assert(pos != std::string::npos && "Unrecognized constraint");
228   start = CStr.find_first_not_of(" \t");
229   std::string Name = CStr.substr(start, pos - start);
230 
231   // TIED_TO: $src1 = $dst
232   wpos = Name.find_first_of(" \t");
233   if (wpos == std::string::npos)
234     PrintFatalError("Illegal format for tied-to constraint: '" + CStr + "'");
235   std::string DestOpName = Name.substr(0, wpos);
236   std::pair<unsigned,unsigned> DestOp = Ops.ParseOperandName(DestOpName, false);
237 
238   Name = CStr.substr(pos+1);
239   wpos = Name.find_first_not_of(" \t");
240   if (wpos == std::string::npos)
241     PrintFatalError("Illegal format for tied-to constraint: '" + CStr + "'");
242 
243   std::string SrcOpName = Name.substr(wpos);
244   std::pair<unsigned,unsigned> SrcOp = Ops.ParseOperandName(SrcOpName, false);
245   if (SrcOp > DestOp) {
246     std::swap(SrcOp, DestOp);
247     std::swap(SrcOpName, DestOpName);
248   }
249 
250   unsigned FlatOpNo = Ops.getFlattenedOperandNumber(SrcOp);
251 
252   if (!Ops[DestOp.first].Constraints[DestOp.second].isNone())
253     PrintFatalError("Operand '" + DestOpName +
254       "' cannot have multiple constraints!");
255   Ops[DestOp.first].Constraints[DestOp.second] =
256     CGIOperandList::ConstraintInfo::getTied(FlatOpNo);
257 }
258 
ParseConstraints(const std::string & CStr,CGIOperandList & Ops)259 static void ParseConstraints(const std::string &CStr, CGIOperandList &Ops) {
260   if (CStr.empty()) return;
261 
262   const std::string delims(",");
263   std::string::size_type bidx, eidx;
264 
265   bidx = CStr.find_first_not_of(delims);
266   while (bidx != std::string::npos) {
267     eidx = CStr.find_first_of(delims, bidx);
268     if (eidx == std::string::npos)
269       eidx = CStr.length();
270 
271     ParseConstraint(CStr.substr(bidx, eidx - bidx), Ops);
272     bidx = CStr.find_first_not_of(delims, eidx);
273   }
274 }
275 
ProcessDisableEncoding(std::string DisableEncoding)276 void CGIOperandList::ProcessDisableEncoding(std::string DisableEncoding) {
277   while (1) {
278     std::pair<StringRef, StringRef> P = getToken(DisableEncoding, " ,\t");
279     std::string OpName = P.first;
280     DisableEncoding = P.second;
281     if (OpName.empty()) break;
282 
283     // Figure out which operand this is.
284     std::pair<unsigned,unsigned> Op = ParseOperandName(OpName, false);
285 
286     // Mark the operand as not-to-be encoded.
287     if (Op.second >= OperandList[Op.first].DoNotEncode.size())
288       OperandList[Op.first].DoNotEncode.resize(Op.second+1);
289     OperandList[Op.first].DoNotEncode[Op.second] = true;
290   }
291 
292 }
293 
294 //===----------------------------------------------------------------------===//
295 // CodeGenInstruction Implementation
296 //===----------------------------------------------------------------------===//
297 
CodeGenInstruction(Record * R)298 CodeGenInstruction::CodeGenInstruction(Record *R)
299   : TheDef(R), Operands(R), InferredFrom(nullptr) {
300   Namespace = R->getValueAsString("Namespace");
301   AsmString = R->getValueAsString("AsmString");
302 
303   isReturn     = R->getValueAsBit("isReturn");
304   isBranch     = R->getValueAsBit("isBranch");
305   isIndirectBranch = R->getValueAsBit("isIndirectBranch");
306   isCompare    = R->getValueAsBit("isCompare");
307   isMoveImm    = R->getValueAsBit("isMoveImm");
308   isBitcast    = R->getValueAsBit("isBitcast");
309   isSelect     = R->getValueAsBit("isSelect");
310   isBarrier    = R->getValueAsBit("isBarrier");
311   isCall       = R->getValueAsBit("isCall");
312   canFoldAsLoad = R->getValueAsBit("canFoldAsLoad");
313   isPredicable = Operands.isPredicable || R->getValueAsBit("isPredicable");
314   isConvertibleToThreeAddress = R->getValueAsBit("isConvertibleToThreeAddress");
315   isCommutable = R->getValueAsBit("isCommutable");
316   isTerminator = R->getValueAsBit("isTerminator");
317   isReMaterializable = R->getValueAsBit("isReMaterializable");
318   hasDelaySlot = R->getValueAsBit("hasDelaySlot");
319   usesCustomInserter = R->getValueAsBit("usesCustomInserter");
320   hasPostISelHook = R->getValueAsBit("hasPostISelHook");
321   hasCtrlDep   = R->getValueAsBit("hasCtrlDep");
322   isNotDuplicable = R->getValueAsBit("isNotDuplicable");
323   isRegSequence = R->getValueAsBit("isRegSequence");
324   isExtractSubreg = R->getValueAsBit("isExtractSubreg");
325   isInsertSubreg = R->getValueAsBit("isInsertSubreg");
326   isConvergent = R->getValueAsBit("isConvergent");
327   hasNoSchedulingInfo = R->getValueAsBit("hasNoSchedulingInfo");
328 
329   bool Unset;
330   mayLoad      = R->getValueAsBitOrUnset("mayLoad", Unset);
331   mayLoad_Unset = Unset;
332   mayStore     = R->getValueAsBitOrUnset("mayStore", Unset);
333   mayStore_Unset = Unset;
334   hasSideEffects = R->getValueAsBitOrUnset("hasSideEffects", Unset);
335   hasSideEffects_Unset = Unset;
336 
337   isAsCheapAsAMove = R->getValueAsBit("isAsCheapAsAMove");
338   hasExtraSrcRegAllocReq = R->getValueAsBit("hasExtraSrcRegAllocReq");
339   hasExtraDefRegAllocReq = R->getValueAsBit("hasExtraDefRegAllocReq");
340   isCodeGenOnly = R->getValueAsBit("isCodeGenOnly");
341   isPseudo = R->getValueAsBit("isPseudo");
342   ImplicitDefs = R->getValueAsListOfDefs("Defs");
343   ImplicitUses = R->getValueAsListOfDefs("Uses");
344 
345   // Parse Constraints.
346   ParseConstraints(R->getValueAsString("Constraints"), Operands);
347 
348   // Parse the DisableEncoding field.
349   Operands.ProcessDisableEncoding(R->getValueAsString("DisableEncoding"));
350 
351   // First check for a ComplexDeprecationPredicate.
352   if (R->getValue("ComplexDeprecationPredicate")) {
353     HasComplexDeprecationPredicate = true;
354     DeprecatedReason = R->getValueAsString("ComplexDeprecationPredicate");
355   } else if (RecordVal *Dep = R->getValue("DeprecatedFeatureMask")) {
356     // Check if we have a Subtarget feature mask.
357     HasComplexDeprecationPredicate = false;
358     DeprecatedReason = Dep->getValue()->getAsString();
359   } else {
360     // This instruction isn't deprecated.
361     HasComplexDeprecationPredicate = false;
362     DeprecatedReason = "";
363   }
364 }
365 
366 /// HasOneImplicitDefWithKnownVT - If the instruction has at least one
367 /// implicit def and it has a known VT, return the VT, otherwise return
368 /// MVT::Other.
369 MVT::SimpleValueType CodeGenInstruction::
HasOneImplicitDefWithKnownVT(const CodeGenTarget & TargetInfo) const370 HasOneImplicitDefWithKnownVT(const CodeGenTarget &TargetInfo) const {
371   if (ImplicitDefs.empty()) return MVT::Other;
372 
373   // Check to see if the first implicit def has a resolvable type.
374   Record *FirstImplicitDef = ImplicitDefs[0];
375   assert(FirstImplicitDef->isSubClassOf("Register"));
376   const std::vector<MVT::SimpleValueType> &RegVTs =
377     TargetInfo.getRegisterVTs(FirstImplicitDef);
378   if (RegVTs.size() == 1)
379     return RegVTs[0];
380   return MVT::Other;
381 }
382 
383 
384 /// FlattenAsmStringVariants - Flatten the specified AsmString to only
385 /// include text from the specified variant, returning the new string.
386 std::string CodeGenInstruction::
FlattenAsmStringVariants(StringRef Cur,unsigned Variant)387 FlattenAsmStringVariants(StringRef Cur, unsigned Variant) {
388   std::string Res = "";
389 
390   for (;;) {
391     // Find the start of the next variant string.
392     size_t VariantsStart = 0;
393     for (size_t e = Cur.size(); VariantsStart != e; ++VariantsStart)
394       if (Cur[VariantsStart] == '{' &&
395           (VariantsStart == 0 || (Cur[VariantsStart-1] != '$' &&
396                                   Cur[VariantsStart-1] != '\\')))
397         break;
398 
399     // Add the prefix to the result.
400     Res += Cur.slice(0, VariantsStart);
401     if (VariantsStart == Cur.size())
402       break;
403 
404     ++VariantsStart; // Skip the '{'.
405 
406     // Scan to the end of the variants string.
407     size_t VariantsEnd = VariantsStart;
408     unsigned NestedBraces = 1;
409     for (size_t e = Cur.size(); VariantsEnd != e; ++VariantsEnd) {
410       if (Cur[VariantsEnd] == '}' && Cur[VariantsEnd-1] != '\\') {
411         if (--NestedBraces == 0)
412           break;
413       } else if (Cur[VariantsEnd] == '{')
414         ++NestedBraces;
415     }
416 
417     // Select the Nth variant (or empty).
418     StringRef Selection = Cur.slice(VariantsStart, VariantsEnd);
419     for (unsigned i = 0; i != Variant; ++i)
420       Selection = Selection.split('|').second;
421     Res += Selection.split('|').first;
422 
423     assert(VariantsEnd != Cur.size() &&
424            "Unterminated variants in assembly string!");
425     Cur = Cur.substr(VariantsEnd + 1);
426   }
427 
428   return Res;
429 }
430 
431 
432 //===----------------------------------------------------------------------===//
433 /// CodeGenInstAlias Implementation
434 //===----------------------------------------------------------------------===//
435 
436 /// tryAliasOpMatch - This is a helper function for the CodeGenInstAlias
437 /// constructor.  It checks if an argument in an InstAlias pattern matches
438 /// the corresponding operand of the instruction.  It returns true on a
439 /// 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)440 bool CodeGenInstAlias::tryAliasOpMatch(DagInit *Result, unsigned AliasOpNo,
441                                        Record *InstOpRec, bool hasSubOps,
442                                        ArrayRef<SMLoc> Loc, CodeGenTarget &T,
443                                        ResultOperand &ResOp) {
444   Init *Arg = Result->getArg(AliasOpNo);
445   DefInit *ADI = dyn_cast<DefInit>(Arg);
446   Record *ResultRecord = ADI ? ADI->getDef() : nullptr;
447 
448   if (ADI && ADI->getDef() == InstOpRec) {
449     // If the operand is a record, it must have a name, and the record type
450     // must match up with the instruction's argument type.
451     if (Result->getArgName(AliasOpNo).empty())
452       PrintFatalError(Loc, "result argument #" + Twine(AliasOpNo) +
453                            " must have a name!");
454     ResOp = ResultOperand(Result->getArgName(AliasOpNo), ResultRecord);
455     return true;
456   }
457 
458   // For register operands, the source register class can be a subclass
459   // of the instruction register class, not just an exact match.
460   if (InstOpRec->isSubClassOf("RegisterOperand"))
461     InstOpRec = InstOpRec->getValueAsDef("RegClass");
462 
463   if (ADI && ADI->getDef()->isSubClassOf("RegisterOperand"))
464     ADI = ADI->getDef()->getValueAsDef("RegClass")->getDefInit();
465 
466   if (ADI && ADI->getDef()->isSubClassOf("RegisterClass")) {
467     if (!InstOpRec->isSubClassOf("RegisterClass"))
468       return false;
469     if (!T.getRegisterClass(InstOpRec)
470               .hasSubClass(&T.getRegisterClass(ADI->getDef())))
471       return false;
472     ResOp = ResultOperand(Result->getArgName(AliasOpNo), ResultRecord);
473     return true;
474   }
475 
476   // Handle explicit registers.
477   if (ADI && ADI->getDef()->isSubClassOf("Register")) {
478     if (InstOpRec->isSubClassOf("OptionalDefOperand")) {
479       DagInit *DI = InstOpRec->getValueAsDag("MIOperandInfo");
480       // The operand info should only have a single (register) entry. We
481       // want the register class of it.
482       InstOpRec = cast<DefInit>(DI->getArg(0))->getDef();
483     }
484 
485     if (!InstOpRec->isSubClassOf("RegisterClass"))
486       return false;
487 
488     if (!T.getRegisterClass(InstOpRec)
489         .contains(T.getRegBank().getReg(ADI->getDef())))
490       PrintFatalError(Loc, "fixed register " + ADI->getDef()->getName() +
491                       " is not a member of the " + InstOpRec->getName() +
492                       " register class!");
493 
494     if (!Result->getArgName(AliasOpNo).empty())
495       PrintFatalError(Loc, "result fixed register argument must "
496                       "not have a name!");
497 
498     ResOp = ResultOperand(ResultRecord);
499     return true;
500   }
501 
502   // Handle "zero_reg" for optional def operands.
503   if (ADI && ADI->getDef()->getName() == "zero_reg") {
504 
505     // Check if this is an optional def.
506     // Tied operands where the source is a sub-operand of a complex operand
507     // need to represent both operands in the alias destination instruction.
508     // Allow zero_reg for the tied portion. This can and should go away once
509     // the MC representation of things doesn't use tied operands at all.
510     //if (!InstOpRec->isSubClassOf("OptionalDefOperand"))
511     //  throw TGError(Loc, "reg0 used for result that is not an "
512     //                "OptionalDefOperand!");
513 
514     ResOp = ResultOperand(static_cast<Record*>(nullptr));
515     return true;
516   }
517 
518   // Literal integers.
519   if (IntInit *II = dyn_cast<IntInit>(Arg)) {
520     if (hasSubOps || !InstOpRec->isSubClassOf("Operand"))
521       return false;
522     // Integer arguments can't have names.
523     if (!Result->getArgName(AliasOpNo).empty())
524       PrintFatalError(Loc, "result argument #" + Twine(AliasOpNo) +
525                       " must not have a name!");
526     ResOp = ResultOperand(II->getValue());
527     return true;
528   }
529 
530   // Bits<n> (also used for 0bxx literals)
531   if (BitsInit *BI = dyn_cast<BitsInit>(Arg)) {
532     if (hasSubOps || !InstOpRec->isSubClassOf("Operand"))
533       return false;
534     if (!BI->isComplete())
535       return false;
536     // Convert the bits init to an integer and use that for the result.
537     IntInit *II =
538       dyn_cast_or_null<IntInit>(BI->convertInitializerTo(IntRecTy::get()));
539     if (!II)
540       return false;
541     ResOp = ResultOperand(II->getValue());
542     return true;
543   }
544 
545   // If both are Operands with the same MVT, allow the conversion. It's
546   // up to the user to make sure the values are appropriate, just like
547   // for isel Pat's.
548   if (InstOpRec->isSubClassOf("Operand") && ADI &&
549       ADI->getDef()->isSubClassOf("Operand")) {
550     // FIXME: What other attributes should we check here? Identical
551     // MIOperandInfo perhaps?
552     if (InstOpRec->getValueInit("Type") != ADI->getDef()->getValueInit("Type"))
553       return false;
554     ResOp = ResultOperand(Result->getArgName(AliasOpNo), ADI->getDef());
555     return true;
556   }
557 
558   return false;
559 }
560 
getMINumOperands() const561 unsigned CodeGenInstAlias::ResultOperand::getMINumOperands() const {
562   if (!isRecord())
563     return 1;
564 
565   Record *Rec = getRecord();
566   if (!Rec->isSubClassOf("Operand"))
567     return 1;
568 
569   DagInit *MIOpInfo = Rec->getValueAsDag("MIOperandInfo");
570   if (MIOpInfo->getNumArgs() == 0) {
571     // Unspecified, so it defaults to 1
572     return 1;
573   }
574 
575   return MIOpInfo->getNumArgs();
576 }
577 
CodeGenInstAlias(Record * R,unsigned Variant,CodeGenTarget & T)578 CodeGenInstAlias::CodeGenInstAlias(Record *R, unsigned Variant,
579                                    CodeGenTarget &T)
580     : TheDef(R) {
581   Result = R->getValueAsDag("ResultInst");
582   AsmString = R->getValueAsString("AsmString");
583   AsmString = CodeGenInstruction::FlattenAsmStringVariants(AsmString, Variant);
584 
585 
586   // Verify that the root of the result is an instruction.
587   DefInit *DI = dyn_cast<DefInit>(Result->getOperator());
588   if (!DI || !DI->getDef()->isSubClassOf("Instruction"))
589     PrintFatalError(R->getLoc(),
590                     "result of inst alias should be an instruction");
591 
592   ResultInst = &T.getInstruction(DI->getDef());
593 
594   // NameClass - If argument names are repeated, we need to verify they have
595   // the same class.
596   StringMap<Record*> NameClass;
597   for (unsigned i = 0, e = Result->getNumArgs(); i != e; ++i) {
598     DefInit *ADI = dyn_cast<DefInit>(Result->getArg(i));
599     if (!ADI || Result->getArgName(i).empty())
600       continue;
601     // Verify we don't have something like: (someinst GR16:$foo, GR32:$foo)
602     // $foo can exist multiple times in the result list, but it must have the
603     // same type.
604     Record *&Entry = NameClass[Result->getArgName(i)];
605     if (Entry && Entry != ADI->getDef())
606       PrintFatalError(R->getLoc(), "result value $" + Result->getArgName(i) +
607                       " is both " + Entry->getName() + " and " +
608                       ADI->getDef()->getName() + "!");
609     Entry = ADI->getDef();
610   }
611 
612   // Decode and validate the arguments of the result.
613   unsigned AliasOpNo = 0;
614   for (unsigned i = 0, e = ResultInst->Operands.size(); i != e; ++i) {
615 
616     // Tied registers don't have an entry in the result dag unless they're part
617     // of a complex operand, in which case we include them anyways, as we
618     // don't have any other way to specify the whole operand.
619     if (ResultInst->Operands[i].MINumOperands == 1 &&
620         ResultInst->Operands[i].getTiedRegister() != -1)
621       continue;
622 
623     if (AliasOpNo >= Result->getNumArgs())
624       PrintFatalError(R->getLoc(), "not enough arguments for instruction!");
625 
626     Record *InstOpRec = ResultInst->Operands[i].Rec;
627     unsigned NumSubOps = ResultInst->Operands[i].MINumOperands;
628     ResultOperand ResOp(static_cast<int64_t>(0));
629     if (tryAliasOpMatch(Result, AliasOpNo, InstOpRec, (NumSubOps > 1),
630                         R->getLoc(), T, ResOp)) {
631       // If this is a simple operand, or a complex operand with a custom match
632       // class, then we can match is verbatim.
633       if (NumSubOps == 1 ||
634           (InstOpRec->getValue("ParserMatchClass") &&
635            InstOpRec->getValueAsDef("ParserMatchClass")
636              ->getValueAsString("Name") != "Imm")) {
637         ResultOperands.push_back(ResOp);
638         ResultInstOperandIndex.push_back(std::make_pair(i, -1));
639         ++AliasOpNo;
640 
641       // Otherwise, we need to match each of the suboperands individually.
642       } else {
643          DagInit *MIOI = ResultInst->Operands[i].MIOperandInfo;
644          for (unsigned SubOp = 0; SubOp != NumSubOps; ++SubOp) {
645           Record *SubRec = cast<DefInit>(MIOI->getArg(SubOp))->getDef();
646 
647           // Take care to instantiate each of the suboperands with the correct
648           // nomenclature: $foo.bar
649           ResultOperands.emplace_back(Result->getArgName(AliasOpNo) + "." +
650                                           MIOI->getArgName(SubOp),
651                                       SubRec);
652           ResultInstOperandIndex.push_back(std::make_pair(i, SubOp));
653          }
654          ++AliasOpNo;
655       }
656       continue;
657     }
658 
659     // If the argument did not match the instruction operand, and the operand
660     // is composed of multiple suboperands, try matching the suboperands.
661     if (NumSubOps > 1) {
662       DagInit *MIOI = ResultInst->Operands[i].MIOperandInfo;
663       for (unsigned SubOp = 0; SubOp != NumSubOps; ++SubOp) {
664         if (AliasOpNo >= Result->getNumArgs())
665           PrintFatalError(R->getLoc(), "not enough arguments for instruction!");
666         Record *SubRec = cast<DefInit>(MIOI->getArg(SubOp))->getDef();
667         if (tryAliasOpMatch(Result, AliasOpNo, SubRec, false,
668                             R->getLoc(), T, ResOp)) {
669           ResultOperands.push_back(ResOp);
670           ResultInstOperandIndex.push_back(std::make_pair(i, SubOp));
671           ++AliasOpNo;
672         } else {
673           PrintFatalError(R->getLoc(), "result argument #" + Twine(AliasOpNo) +
674                         " does not match instruction operand class " +
675                         (SubOp == 0 ? InstOpRec->getName() :SubRec->getName()));
676         }
677       }
678       continue;
679     }
680     PrintFatalError(R->getLoc(), "result argument #" + Twine(AliasOpNo) +
681                     " does not match instruction operand class " +
682                     InstOpRec->getName());
683   }
684 
685   if (AliasOpNo != Result->getNumArgs())
686     PrintFatalError(R->getLoc(), "too many operands for instruction!");
687 }
688