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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 "Error.h"
17 #include "Record.h"
18 #include "llvm/ADT/StringExtras.h"
19 #include "llvm/ADT/StringMap.h"
20 #include "llvm/ADT/STLExtras.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 = dynamic_cast<DefInit*>(OutDI->getOperator())) {
36     if (Init->getDef()->getName() != "outs")
37       throw R->getName() + ": invalid def name for output list: use 'outs'";
38   } else
39     throw R->getName() + ": invalid output list: use 'outs'";
40 
41   NumDefs = OutDI->getNumArgs();
42 
43   DagInit *InDI = R->getValueAsDag("InOperandList");
44   if (DefInit *Init = dynamic_cast<DefInit*>(InDI->getOperator())) {
45     if (Init->getDef()->getName() != "ins")
46       throw R->getName() + ": invalid def name for input list: use 'ins'";
47   } else
48     throw 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 = dynamic_cast<DefInit*>(ArgInit);
64     if (!Arg)
65       throw "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     unsigned NumOps = 1;
72     DagInit *MIOpInfo = 0;
73     if (Rec->isSubClassOf("RegisterOperand")) {
74       PrintMethod = Rec->getValueAsString("PrintMethod");
75     } else if (Rec->isSubClassOf("Operand")) {
76       PrintMethod = Rec->getValueAsString("PrintMethod");
77       OperandType = Rec->getValueAsString("OperandType");
78       // If there is an explicit encoder method, use it.
79       EncoderMethod = Rec->getValueAsString("EncoderMethod");
80       MIOpInfo = Rec->getValueAsDag("MIOperandInfo");
81 
82       // Verify that MIOpInfo has an 'ops' root value.
83       if (!dynamic_cast<DefInit*>(MIOpInfo->getOperator()) ||
84           dynamic_cast<DefInit*>(MIOpInfo->getOperator())
85           ->getDef()->getName() != "ops")
86         throw "Bad value for MIOperandInfo in operand '" + Rec->getName() +
87         "'\n";
88 
89       // If we have MIOpInfo, then we have #operands equal to number of entries
90       // in MIOperandInfo.
91       if (unsigned NumArgs = MIOpInfo->getNumArgs())
92         NumOps = NumArgs;
93 
94       if (Rec->isSubClassOf("PredicateOperand"))
95         isPredicable = true;
96       else if (Rec->isSubClassOf("OptionalDefOperand"))
97         hasOptionalDef = true;
98     } else if (Rec->getName() == "variable_ops") {
99       isVariadic = true;
100       continue;
101     } else if (Rec->isSubClassOf("RegisterClass")) {
102       OperandType = "OPERAND_REGISTER";
103     } else if (!Rec->isSubClassOf("PointerLikeRegClass") &&
104                Rec->getName() != "unknown")
105       throw "Unknown operand class '" + Rec->getName() +
106       "' in '" + R->getName() + "' instruction!";
107 
108     // Check that the operand has a name and that it's unique.
109     if (ArgName.empty())
110       throw "In instruction '" + R->getName() + "', operand #" + utostr(i) +
111       " has no name!";
112     if (!OperandNames.insert(ArgName).second)
113       throw "In instruction '" + R->getName() + "', operand #" + utostr(i) +
114       " has the same name as a previous operand!";
115 
116     OperandList.push_back(OperandInfo(Rec, ArgName, PrintMethod, EncoderMethod,
117                                       OperandType, MIOperandNo, NumOps,
118                                       MIOpInfo));
119     MIOperandNo += NumOps;
120   }
121 
122 
123   // Make sure the constraints list for each operand is large enough to hold
124   // constraint info, even if none is present.
125   for (unsigned i = 0, e = OperandList.size(); i != e; ++i)
126     OperandList[i].Constraints.resize(OperandList[i].MINumOperands);
127 }
128 
129 
130 /// getOperandNamed - Return the index of the operand with the specified
131 /// non-empty name.  If the instruction does not have an operand with the
132 /// specified name, throw an exception.
133 ///
getOperandNamed(StringRef Name) const134 unsigned CGIOperandList::getOperandNamed(StringRef Name) const {
135   unsigned OpIdx;
136   if (hasOperandNamed(Name, OpIdx)) return OpIdx;
137   throw "'" + TheDef->getName() + "' does not have an operand named '$" +
138     Name.str() + "'!";
139 }
140 
141 /// hasOperandNamed - Query whether the instruction has an operand of the
142 /// given name. If so, return true and set OpIdx to the index of the
143 /// operand. Otherwise, return false.
hasOperandNamed(StringRef Name,unsigned & OpIdx) const144 bool CGIOperandList::hasOperandNamed(StringRef Name, unsigned &OpIdx) const {
145   assert(!Name.empty() && "Cannot search for operand with no name!");
146   for (unsigned i = 0, e = OperandList.size(); i != e; ++i)
147     if (OperandList[i].Name == Name) {
148       OpIdx = i;
149       return true;
150     }
151   return false;
152 }
153 
154 std::pair<unsigned,unsigned>
ParseOperandName(const std::string & Op,bool AllowWholeOp)155 CGIOperandList::ParseOperandName(const std::string &Op, bool AllowWholeOp) {
156   if (Op.empty() || Op[0] != '$')
157     throw TheDef->getName() + ": Illegal operand name: '" + Op + "'";
158 
159   std::string OpName = Op.substr(1);
160   std::string SubOpName;
161 
162   // Check to see if this is $foo.bar.
163   std::string::size_type DotIdx = OpName.find_first_of(".");
164   if (DotIdx != std::string::npos) {
165     SubOpName = OpName.substr(DotIdx+1);
166     if (SubOpName.empty())
167       throw TheDef->getName() + ": illegal empty suboperand name in '" +Op +"'";
168     OpName = OpName.substr(0, DotIdx);
169   }
170 
171   unsigned OpIdx = getOperandNamed(OpName);
172 
173   if (SubOpName.empty()) {  // If no suboperand name was specified:
174     // If one was needed, throw.
175     if (OperandList[OpIdx].MINumOperands > 1 && !AllowWholeOp &&
176         SubOpName.empty())
177       throw TheDef->getName() + ": Illegal to refer to"
178       " whole operand part of complex operand '" + Op + "'";
179 
180     // Otherwise, return the operand.
181     return std::make_pair(OpIdx, 0U);
182   }
183 
184   // Find the suboperand number involved.
185   DagInit *MIOpInfo = OperandList[OpIdx].MIOperandInfo;
186   if (MIOpInfo == 0)
187     throw TheDef->getName() + ": unknown suboperand name in '" + Op + "'";
188 
189   // Find the operand with the right name.
190   for (unsigned i = 0, e = MIOpInfo->getNumArgs(); i != e; ++i)
191     if (MIOpInfo->getArgName(i) == SubOpName)
192       return std::make_pair(OpIdx, i);
193 
194   // Otherwise, didn't find it!
195   throw TheDef->getName() + ": unknown suboperand name in '" + Op + "'";
196 }
197 
ParseConstraint(const std::string & CStr,CGIOperandList & Ops)198 static void ParseConstraint(const std::string &CStr, CGIOperandList &Ops) {
199   // EARLY_CLOBBER: @early $reg
200   std::string::size_type wpos = CStr.find_first_of(" \t");
201   std::string::size_type start = CStr.find_first_not_of(" \t");
202   std::string Tok = CStr.substr(start, wpos - start);
203   if (Tok == "@earlyclobber") {
204     std::string Name = CStr.substr(wpos+1);
205     wpos = Name.find_first_not_of(" \t");
206     if (wpos == std::string::npos)
207       throw "Illegal format for @earlyclobber constraint: '" + CStr + "'";
208     Name = Name.substr(wpos);
209     std::pair<unsigned,unsigned> Op = Ops.ParseOperandName(Name, false);
210 
211     // Build the string for the operand
212     if (!Ops[Op.first].Constraints[Op.second].isNone())
213       throw "Operand '" + Name + "' cannot have multiple constraints!";
214     Ops[Op.first].Constraints[Op.second] =
215     CGIOperandList::ConstraintInfo::getEarlyClobber();
216     return;
217   }
218 
219   // Only other constraint is "TIED_TO" for now.
220   std::string::size_type pos = CStr.find_first_of('=');
221   assert(pos != std::string::npos && "Unrecognized constraint");
222   start = CStr.find_first_not_of(" \t");
223   std::string Name = CStr.substr(start, pos - start);
224 
225   // TIED_TO: $src1 = $dst
226   wpos = Name.find_first_of(" \t");
227   if (wpos == std::string::npos)
228     throw "Illegal format for tied-to constraint: '" + CStr + "'";
229   std::string DestOpName = Name.substr(0, wpos);
230   std::pair<unsigned,unsigned> DestOp = Ops.ParseOperandName(DestOpName, false);
231 
232   Name = CStr.substr(pos+1);
233   wpos = Name.find_first_not_of(" \t");
234   if (wpos == std::string::npos)
235     throw "Illegal format for tied-to constraint: '" + CStr + "'";
236 
237   std::pair<unsigned,unsigned> SrcOp =
238   Ops.ParseOperandName(Name.substr(wpos), false);
239   if (SrcOp > DestOp)
240     throw "Illegal tied-to operand constraint '" + CStr + "'";
241 
242 
243   unsigned FlatOpNo = Ops.getFlattenedOperandNumber(SrcOp);
244 
245   if (!Ops[DestOp.first].Constraints[DestOp.second].isNone())
246     throw "Operand '" + DestOpName + "' cannot have multiple constraints!";
247   Ops[DestOp.first].Constraints[DestOp.second] =
248   CGIOperandList::ConstraintInfo::getTied(FlatOpNo);
249 }
250 
ParseConstraints(const std::string & CStr,CGIOperandList & Ops)251 static void ParseConstraints(const std::string &CStr, CGIOperandList &Ops) {
252   if (CStr.empty()) return;
253 
254   const std::string delims(",");
255   std::string::size_type bidx, eidx;
256 
257   bidx = CStr.find_first_not_of(delims);
258   while (bidx != std::string::npos) {
259     eidx = CStr.find_first_of(delims, bidx);
260     if (eidx == std::string::npos)
261       eidx = CStr.length();
262 
263     ParseConstraint(CStr.substr(bidx, eidx - bidx), Ops);
264     bidx = CStr.find_first_not_of(delims, eidx);
265   }
266 }
267 
ProcessDisableEncoding(std::string DisableEncoding)268 void CGIOperandList::ProcessDisableEncoding(std::string DisableEncoding) {
269   while (1) {
270     std::string OpName;
271     tie(OpName, DisableEncoding) = getToken(DisableEncoding, " ,\t");
272     if (OpName.empty()) break;
273 
274     // Figure out which operand this is.
275     std::pair<unsigned,unsigned> Op = ParseOperandName(OpName, false);
276 
277     // Mark the operand as not-to-be encoded.
278     if (Op.second >= OperandList[Op.first].DoNotEncode.size())
279       OperandList[Op.first].DoNotEncode.resize(Op.second+1);
280     OperandList[Op.first].DoNotEncode[Op.second] = true;
281   }
282 
283 }
284 
285 //===----------------------------------------------------------------------===//
286 // CodeGenInstruction Implementation
287 //===----------------------------------------------------------------------===//
288 
CodeGenInstruction(Record * R)289 CodeGenInstruction::CodeGenInstruction(Record *R) : TheDef(R), Operands(R) {
290   Namespace = R->getValueAsString("Namespace");
291   AsmString = R->getValueAsString("AsmString");
292 
293   isReturn     = R->getValueAsBit("isReturn");
294   isBranch     = R->getValueAsBit("isBranch");
295   isIndirectBranch = R->getValueAsBit("isIndirectBranch");
296   isCompare    = R->getValueAsBit("isCompare");
297   isMoveImm    = R->getValueAsBit("isMoveImm");
298   isBitcast    = R->getValueAsBit("isBitcast");
299   isBarrier    = R->getValueAsBit("isBarrier");
300   isCall       = R->getValueAsBit("isCall");
301   canFoldAsLoad = R->getValueAsBit("canFoldAsLoad");
302   mayLoad      = R->getValueAsBit("mayLoad");
303   mayStore     = R->getValueAsBit("mayStore");
304   isPredicable = Operands.isPredicable || R->getValueAsBit("isPredicable");
305   isConvertibleToThreeAddress = R->getValueAsBit("isConvertibleToThreeAddress");
306   isCommutable = R->getValueAsBit("isCommutable");
307   isTerminator = R->getValueAsBit("isTerminator");
308   isReMaterializable = R->getValueAsBit("isReMaterializable");
309   hasDelaySlot = R->getValueAsBit("hasDelaySlot");
310   usesCustomInserter = R->getValueAsBit("usesCustomInserter");
311   hasCtrlDep   = R->getValueAsBit("hasCtrlDep");
312   isNotDuplicable = R->getValueAsBit("isNotDuplicable");
313   hasSideEffects = R->getValueAsBit("hasSideEffects");
314   neverHasSideEffects = R->getValueAsBit("neverHasSideEffects");
315   isAsCheapAsAMove = R->getValueAsBit("isAsCheapAsAMove");
316   hasExtraSrcRegAllocReq = R->getValueAsBit("hasExtraSrcRegAllocReq");
317   hasExtraDefRegAllocReq = R->getValueAsBit("hasExtraDefRegAllocReq");
318   isCodeGenOnly = R->getValueAsBit("isCodeGenOnly");
319   isPseudo = R->getValueAsBit("isPseudo");
320   ImplicitDefs = R->getValueAsListOfDefs("Defs");
321   ImplicitUses = R->getValueAsListOfDefs("Uses");
322 
323   if (neverHasSideEffects + hasSideEffects > 1)
324     throw R->getName() + ": multiple conflicting side-effect flags set!";
325 
326   // Parse Constraints.
327   ParseConstraints(R->getValueAsString("Constraints"), Operands);
328 
329   // Parse the DisableEncoding field.
330   Operands.ProcessDisableEncoding(R->getValueAsString("DisableEncoding"));
331 }
332 
333 /// HasOneImplicitDefWithKnownVT - If the instruction has at least one
334 /// implicit def and it has a known VT, return the VT, otherwise return
335 /// MVT::Other.
336 MVT::SimpleValueType CodeGenInstruction::
HasOneImplicitDefWithKnownVT(const CodeGenTarget & TargetInfo) const337 HasOneImplicitDefWithKnownVT(const CodeGenTarget &TargetInfo) const {
338   if (ImplicitDefs.empty()) return MVT::Other;
339 
340   // Check to see if the first implicit def has a resolvable type.
341   Record *FirstImplicitDef = ImplicitDefs[0];
342   assert(FirstImplicitDef->isSubClassOf("Register"));
343   const std::vector<MVT::SimpleValueType> &RegVTs =
344     TargetInfo.getRegisterVTs(FirstImplicitDef);
345   if (RegVTs.size() == 1)
346     return RegVTs[0];
347   return MVT::Other;
348 }
349 
350 
351 /// FlattenAsmStringVariants - Flatten the specified AsmString to only
352 /// include text from the specified variant, returning the new string.
353 std::string CodeGenInstruction::
FlattenAsmStringVariants(StringRef Cur,unsigned Variant)354 FlattenAsmStringVariants(StringRef Cur, unsigned Variant) {
355   std::string Res = "";
356 
357   for (;;) {
358     // Find the start of the next variant string.
359     size_t VariantsStart = 0;
360     for (size_t e = Cur.size(); VariantsStart != e; ++VariantsStart)
361       if (Cur[VariantsStart] == '{' &&
362           (VariantsStart == 0 || (Cur[VariantsStart-1] != '$' &&
363                                   Cur[VariantsStart-1] != '\\')))
364         break;
365 
366     // Add the prefix to the result.
367     Res += Cur.slice(0, VariantsStart);
368     if (VariantsStart == Cur.size())
369       break;
370 
371     ++VariantsStart; // Skip the '{'.
372 
373     // Scan to the end of the variants string.
374     size_t VariantsEnd = VariantsStart;
375     unsigned NestedBraces = 1;
376     for (size_t e = Cur.size(); VariantsEnd != e; ++VariantsEnd) {
377       if (Cur[VariantsEnd] == '}' && Cur[VariantsEnd-1] != '\\') {
378         if (--NestedBraces == 0)
379           break;
380       } else if (Cur[VariantsEnd] == '{')
381         ++NestedBraces;
382     }
383 
384     // Select the Nth variant (or empty).
385     StringRef Selection = Cur.slice(VariantsStart, VariantsEnd);
386     for (unsigned i = 0; i != Variant; ++i)
387       Selection = Selection.split('|').second;
388     Res += Selection.split('|').first;
389 
390     assert(VariantsEnd != Cur.size() &&
391            "Unterminated variants in assembly string!");
392     Cur = Cur.substr(VariantsEnd + 1);
393   }
394 
395   return Res;
396 }
397 
398 
399 //===----------------------------------------------------------------------===//
400 /// CodeGenInstAlias Implementation
401 //===----------------------------------------------------------------------===//
402 
403 /// tryAliasOpMatch - This is a helper function for the CodeGenInstAlias
404 /// constructor.  It checks if an argument in an InstAlias pattern matches
405 /// the corresponding operand of the instruction.  It returns true on a
406 /// successful match, with ResOp set to the result operand to be used.
tryAliasOpMatch(DagInit * Result,unsigned AliasOpNo,Record * InstOpRec,bool hasSubOps,SMLoc Loc,CodeGenTarget & T,ResultOperand & ResOp)407 bool CodeGenInstAlias::tryAliasOpMatch(DagInit *Result, unsigned AliasOpNo,
408                                        Record *InstOpRec, bool hasSubOps,
409                                        SMLoc Loc, CodeGenTarget &T,
410                                        ResultOperand &ResOp) {
411   Init *Arg = Result->getArg(AliasOpNo);
412   DefInit *ADI = dynamic_cast<DefInit*>(Arg);
413 
414   if (ADI && ADI->getDef() == InstOpRec) {
415     // If the operand is a record, it must have a name, and the record type
416     // must match up with the instruction's argument type.
417     if (Result->getArgName(AliasOpNo).empty())
418       throw TGError(Loc, "result argument #" + utostr(AliasOpNo) +
419                     " must have a name!");
420     ResOp = ResultOperand(Result->getArgName(AliasOpNo), ADI->getDef());
421     return true;
422   }
423 
424   // Handle explicit registers.
425   if (ADI && ADI->getDef()->isSubClassOf("Register")) {
426     if (InstOpRec->isSubClassOf("RegisterOperand"))
427       InstOpRec = InstOpRec->getValueAsDef("RegClass");
428 
429     if (!InstOpRec->isSubClassOf("RegisterClass"))
430       return false;
431 
432     if (!T.getRegisterClass(InstOpRec)
433         .contains(T.getRegBank().getReg(ADI->getDef())))
434       throw TGError(Loc, "fixed register " +ADI->getDef()->getName()
435                     + " is not a member of the " + InstOpRec->getName() +
436                     " register class!");
437 
438     if (!Result->getArgName(AliasOpNo).empty())
439       throw TGError(Loc, "result fixed register argument must "
440                     "not have a name!");
441 
442     ResOp = ResultOperand(ADI->getDef());
443     return true;
444   }
445 
446   // Handle "zero_reg" for optional def operands.
447   if (ADI && ADI->getDef()->getName() == "zero_reg") {
448 
449     // Check if this is an optional def.
450     if (!InstOpRec->isSubClassOf("OptionalDefOperand"))
451       throw TGError(Loc, "reg0 used for result that is not an "
452                     "OptionalDefOperand!");
453 
454     ResOp = ResultOperand(static_cast<Record*>(0));
455     return true;
456   }
457 
458   if (IntInit *II = dynamic_cast<IntInit*>(Arg)) {
459     if (hasSubOps || !InstOpRec->isSubClassOf("Operand"))
460       return false;
461     // Integer arguments can't have names.
462     if (!Result->getArgName(AliasOpNo).empty())
463       throw TGError(Loc, "result argument #" + utostr(AliasOpNo) +
464                     " must not have a name!");
465     ResOp = ResultOperand(II->getValue());
466     return true;
467   }
468 
469   return false;
470 }
471 
CodeGenInstAlias(Record * R,CodeGenTarget & T)472 CodeGenInstAlias::CodeGenInstAlias(Record *R, CodeGenTarget &T) : TheDef(R) {
473   AsmString = R->getValueAsString("AsmString");
474   Result = R->getValueAsDag("ResultInst");
475 
476   // Verify that the root of the result is an instruction.
477   DefInit *DI = dynamic_cast<DefInit*>(Result->getOperator());
478   if (DI == 0 || !DI->getDef()->isSubClassOf("Instruction"))
479     throw TGError(R->getLoc(), "result of inst alias should be an instruction");
480 
481   ResultInst = &T.getInstruction(DI->getDef());
482 
483   // NameClass - If argument names are repeated, we need to verify they have
484   // the same class.
485   StringMap<Record*> NameClass;
486   for (unsigned i = 0, e = Result->getNumArgs(); i != e; ++i) {
487     DefInit *ADI = dynamic_cast<DefInit*>(Result->getArg(i));
488     if (!ADI || Result->getArgName(i).empty())
489       continue;
490     // Verify we don't have something like: (someinst GR16:$foo, GR32:$foo)
491     // $foo can exist multiple times in the result list, but it must have the
492     // same type.
493     Record *&Entry = NameClass[Result->getArgName(i)];
494     if (Entry && Entry != ADI->getDef())
495       throw TGError(R->getLoc(), "result value $" + Result->getArgName(i) +
496                     " is both " + Entry->getName() + " and " +
497                     ADI->getDef()->getName() + "!");
498     Entry = ADI->getDef();
499   }
500 
501   // Decode and validate the arguments of the result.
502   unsigned AliasOpNo = 0;
503   for (unsigned i = 0, e = ResultInst->Operands.size(); i != e; ++i) {
504 
505     // Tied registers don't have an entry in the result dag.
506     if (ResultInst->Operands[i].getTiedRegister() != -1)
507       continue;
508 
509     if (AliasOpNo >= Result->getNumArgs())
510       throw TGError(R->getLoc(), "not enough arguments for instruction!");
511 
512     Record *InstOpRec = ResultInst->Operands[i].Rec;
513     unsigned NumSubOps = ResultInst->Operands[i].MINumOperands;
514     ResultOperand ResOp(static_cast<int64_t>(0));
515     if (tryAliasOpMatch(Result, AliasOpNo, InstOpRec, (NumSubOps > 1),
516                         R->getLoc(), T, ResOp)) {
517       ResultOperands.push_back(ResOp);
518       ResultInstOperandIndex.push_back(std::make_pair(i, -1));
519       ++AliasOpNo;
520       continue;
521     }
522 
523     // If the argument did not match the instruction operand, and the operand
524     // is composed of multiple suboperands, try matching the suboperands.
525     if (NumSubOps > 1) {
526       DagInit *MIOI = ResultInst->Operands[i].MIOperandInfo;
527       for (unsigned SubOp = 0; SubOp != NumSubOps; ++SubOp) {
528         if (AliasOpNo >= Result->getNumArgs())
529           throw TGError(R->getLoc(), "not enough arguments for instruction!");
530         Record *SubRec = dynamic_cast<DefInit*>(MIOI->getArg(SubOp))->getDef();
531         if (tryAliasOpMatch(Result, AliasOpNo, SubRec, false,
532                             R->getLoc(), T, ResOp)) {
533           ResultOperands.push_back(ResOp);
534           ResultInstOperandIndex.push_back(std::make_pair(i, SubOp));
535           ++AliasOpNo;
536         } else {
537           throw TGError(R->getLoc(), "result argument #" + utostr(AliasOpNo) +
538                         " does not match instruction operand class " +
539                         (SubOp == 0 ? InstOpRec->getName() :SubRec->getName()));
540         }
541       }
542       continue;
543     }
544     throw TGError(R->getLoc(), "result argument #" + utostr(AliasOpNo) +
545                   " does not match instruction operand class " +
546                   InstOpRec->getName());
547   }
548 
549   if (AliasOpNo != Result->getNumArgs())
550     throw TGError(R->getLoc(), "too many operands for instruction!");
551 }
552