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>
22using namespace llvm;
23
24//===----------------------------------------------------------------------===//
25// CGIOperandList Implementation
26//===----------------------------------------------------------------------===//
27
28CGIOperandList::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    unsigned NumOps = 1;
72    DagInit *MIOpInfo = nullptr;
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 (!isa<DefInit>(MIOpInfo->getOperator()) ||
84          cast<DefInit>(MIOpInfo->getOperator())->getDef()->getName() != "ops")
85        PrintFatalError("Bad value for MIOperandInfo in operand '" + Rec->getName() +
86          "'\n");
87
88      // If we have MIOpInfo, then we have #operands equal to number of entries
89      // in MIOperandInfo.
90      if (unsigned NumArgs = MIOpInfo->getNumArgs())
91        NumOps = NumArgs;
92
93      if (Rec->isSubClassOf("PredicateOp"))
94        isPredicable = true;
95      else if (Rec->isSubClassOf("OptionalDefOperand"))
96        hasOptionalDef = true;
97    } else if (Rec->getName() == "variable_ops") {
98      isVariadic = true;
99      continue;
100    } else if (Rec->isSubClassOf("RegisterClass")) {
101      OperandType = "OPERAND_REGISTER";
102    } else if (!Rec->isSubClassOf("PointerLikeRegClass") &&
103               !Rec->isSubClassOf("unknown_class"))
104      PrintFatalError("Unknown operand class '" + Rec->getName() +
105        "' in '" + R->getName() + "' instruction!");
106
107    // Check that the operand has a name and that it's unique.
108    if (ArgName.empty())
109      PrintFatalError("In instruction '" + R->getName() + "', operand #" +
110                      Twine(i) + " has no name!");
111    if (!OperandNames.insert(ArgName).second)
112      PrintFatalError("In instruction '" + R->getName() + "', operand #" +
113                      Twine(i) + " has the same name as a previous operand!");
114
115    OperandList.push_back(OperandInfo(Rec, ArgName, PrintMethod, EncoderMethod,
116                                      OperandType, MIOperandNo, NumOps,
117                                      MIOpInfo));
118    MIOperandNo += NumOps;
119  }
120
121
122  // Make sure the constraints list for each operand is large enough to hold
123  // constraint info, even if none is present.
124  for (unsigned i = 0, e = OperandList.size(); i != e; ++i)
125    OperandList[i].Constraints.resize(OperandList[i].MINumOperands);
126}
127
128
129/// getOperandNamed - Return the index of the operand with the specified
130/// non-empty name.  If the instruction does not have an operand with the
131/// specified name, abort.
132///
133unsigned CGIOperandList::getOperandNamed(StringRef Name) const {
134  unsigned OpIdx;
135  if (hasOperandNamed(Name, OpIdx)) return OpIdx;
136  PrintFatalError("'" + TheDef->getName() +
137                  "' does not have an operand named '$" + Name + "'!");
138}
139
140/// hasOperandNamed - Query whether the instruction has an operand of the
141/// given name. If so, return true and set OpIdx to the index of the
142/// operand. Otherwise, return false.
143bool CGIOperandList::hasOperandNamed(StringRef Name, unsigned &OpIdx) const {
144  assert(!Name.empty() && "Cannot search for operand with no name!");
145  for (unsigned i = 0, e = OperandList.size(); i != e; ++i)
146    if (OperandList[i].Name == Name) {
147      OpIdx = i;
148      return true;
149    }
150  return false;
151}
152
153std::pair<unsigned,unsigned>
154CGIOperandList::ParseOperandName(const std::string &Op, bool AllowWholeOp) {
155  if (Op.empty() || Op[0] != '$')
156    PrintFatalError(TheDef->getName() + ": Illegal operand name: '" + Op + "'");
157
158  std::string OpName = Op.substr(1);
159  std::string SubOpName;
160
161  // Check to see if this is $foo.bar.
162  std::string::size_type DotIdx = OpName.find_first_of(".");
163  if (DotIdx != std::string::npos) {
164    SubOpName = OpName.substr(DotIdx+1);
165    if (SubOpName.empty())
166      PrintFatalError(TheDef->getName() + ": illegal empty suboperand name in '" +Op +"'");
167    OpName = OpName.substr(0, DotIdx);
168  }
169
170  unsigned OpIdx = getOperandNamed(OpName);
171
172  if (SubOpName.empty()) {  // If no suboperand name was specified:
173    // If one was needed, throw.
174    if (OperandList[OpIdx].MINumOperands > 1 && !AllowWholeOp &&
175        SubOpName.empty())
176      PrintFatalError(TheDef->getName() + ": Illegal to refer to"
177        " whole operand part of complex operand '" + Op + "'");
178
179    // Otherwise, return the operand.
180    return std::make_pair(OpIdx, 0U);
181  }
182
183  // Find the suboperand number involved.
184  DagInit *MIOpInfo = OperandList[OpIdx].MIOperandInfo;
185  if (!MIOpInfo)
186    PrintFatalError(TheDef->getName() + ": unknown suboperand name in '" + Op + "'");
187
188  // Find the operand with the right name.
189  for (unsigned i = 0, e = MIOpInfo->getNumArgs(); i != e; ++i)
190    if (MIOpInfo->getArgName(i) == SubOpName)
191      return std::make_pair(OpIdx, i);
192
193  // Otherwise, didn't find it!
194  PrintFatalError(TheDef->getName() + ": unknown suboperand name in '" + Op + "'");
195  return std::make_pair(0U, 0U);
196}
197
198static 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      PrintFatalError("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      PrintFatalError("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    PrintFatalError("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    PrintFatalError("Illegal format for tied-to constraint: '" + CStr + "'");
236
237  std::string SrcOpName = Name.substr(wpos);
238  std::pair<unsigned,unsigned> SrcOp = Ops.ParseOperandName(SrcOpName, false);
239  if (SrcOp > DestOp) {
240    std::swap(SrcOp, DestOp);
241    std::swap(SrcOpName, DestOpName);
242  }
243
244  unsigned FlatOpNo = Ops.getFlattenedOperandNumber(SrcOp);
245
246  if (!Ops[DestOp.first].Constraints[DestOp.second].isNone())
247    PrintFatalError("Operand '" + DestOpName +
248      "' cannot have multiple constraints!");
249  Ops[DestOp.first].Constraints[DestOp.second] =
250    CGIOperandList::ConstraintInfo::getTied(FlatOpNo);
251}
252
253static void ParseConstraints(const std::string &CStr, CGIOperandList &Ops) {
254  if (CStr.empty()) return;
255
256  const std::string delims(",");
257  std::string::size_type bidx, eidx;
258
259  bidx = CStr.find_first_not_of(delims);
260  while (bidx != std::string::npos) {
261    eidx = CStr.find_first_of(delims, bidx);
262    if (eidx == std::string::npos)
263      eidx = CStr.length();
264
265    ParseConstraint(CStr.substr(bidx, eidx - bidx), Ops);
266    bidx = CStr.find_first_not_of(delims, eidx);
267  }
268}
269
270void CGIOperandList::ProcessDisableEncoding(std::string DisableEncoding) {
271  while (1) {
272    std::pair<StringRef, StringRef> P = getToken(DisableEncoding, " ,\t");
273    std::string OpName = P.first;
274    DisableEncoding = P.second;
275    if (OpName.empty()) break;
276
277    // Figure out which operand this is.
278    std::pair<unsigned,unsigned> Op = ParseOperandName(OpName, false);
279
280    // Mark the operand as not-to-be encoded.
281    if (Op.second >= OperandList[Op.first].DoNotEncode.size())
282      OperandList[Op.first].DoNotEncode.resize(Op.second+1);
283    OperandList[Op.first].DoNotEncode[Op.second] = true;
284  }
285
286}
287
288//===----------------------------------------------------------------------===//
289// CodeGenInstruction Implementation
290//===----------------------------------------------------------------------===//
291
292CodeGenInstruction::CodeGenInstruction(Record *R)
293  : TheDef(R), Operands(R), InferredFrom(nullptr) {
294  Namespace = R->getValueAsString("Namespace");
295  AsmString = R->getValueAsString("AsmString");
296
297  isReturn     = R->getValueAsBit("isReturn");
298  isBranch     = R->getValueAsBit("isBranch");
299  isIndirectBranch = R->getValueAsBit("isIndirectBranch");
300  isCompare    = R->getValueAsBit("isCompare");
301  isMoveImm    = R->getValueAsBit("isMoveImm");
302  isBitcast    = R->getValueAsBit("isBitcast");
303  isSelect     = R->getValueAsBit("isSelect");
304  isBarrier    = R->getValueAsBit("isBarrier");
305  isCall       = R->getValueAsBit("isCall");
306  canFoldAsLoad = R->getValueAsBit("canFoldAsLoad");
307  isPredicable = Operands.isPredicable || R->getValueAsBit("isPredicable");
308  isConvertibleToThreeAddress = R->getValueAsBit("isConvertibleToThreeAddress");
309  isCommutable = R->getValueAsBit("isCommutable");
310  isTerminator = R->getValueAsBit("isTerminator");
311  isReMaterializable = R->getValueAsBit("isReMaterializable");
312  hasDelaySlot = R->getValueAsBit("hasDelaySlot");
313  usesCustomInserter = R->getValueAsBit("usesCustomInserter");
314  hasPostISelHook = R->getValueAsBit("hasPostISelHook");
315  hasCtrlDep   = R->getValueAsBit("hasCtrlDep");
316  isNotDuplicable = R->getValueAsBit("isNotDuplicable");
317
318  bool Unset;
319  mayLoad      = R->getValueAsBitOrUnset("mayLoad", Unset);
320  mayLoad_Unset = Unset;
321  mayStore     = R->getValueAsBitOrUnset("mayStore", Unset);
322  mayStore_Unset = Unset;
323  hasSideEffects = R->getValueAsBitOrUnset("hasSideEffects", Unset);
324  hasSideEffects_Unset = Unset;
325  neverHasSideEffects = R->getValueAsBit("neverHasSideEffects");
326
327  isAsCheapAsAMove = R->getValueAsBit("isAsCheapAsAMove");
328  hasExtraSrcRegAllocReq = R->getValueAsBit("hasExtraSrcRegAllocReq");
329  hasExtraDefRegAllocReq = R->getValueAsBit("hasExtraDefRegAllocReq");
330  isCodeGenOnly = R->getValueAsBit("isCodeGenOnly");
331  isPseudo = R->getValueAsBit("isPseudo");
332  ImplicitDefs = R->getValueAsListOfDefs("Defs");
333  ImplicitUses = R->getValueAsListOfDefs("Uses");
334
335  if (neverHasSideEffects + hasSideEffects > 1)
336    PrintFatalError(R->getName() + ": multiple conflicting side-effect flags set!");
337
338  // Parse Constraints.
339  ParseConstraints(R->getValueAsString("Constraints"), Operands);
340
341  // Parse the DisableEncoding field.
342  Operands.ProcessDisableEncoding(R->getValueAsString("DisableEncoding"));
343
344  // First check for a ComplexDeprecationPredicate.
345  if (R->getValue("ComplexDeprecationPredicate")) {
346    HasComplexDeprecationPredicate = true;
347    DeprecatedReason = R->getValueAsString("ComplexDeprecationPredicate");
348  } else if (RecordVal *Dep = R->getValue("DeprecatedFeatureMask")) {
349    // Check if we have a Subtarget feature mask.
350    HasComplexDeprecationPredicate = false;
351    DeprecatedReason = Dep->getValue()->getAsString();
352  } else {
353    // This instruction isn't deprecated.
354    HasComplexDeprecationPredicate = false;
355    DeprecatedReason = "";
356  }
357}
358
359/// HasOneImplicitDefWithKnownVT - If the instruction has at least one
360/// implicit def and it has a known VT, return the VT, otherwise return
361/// MVT::Other.
362MVT::SimpleValueType CodeGenInstruction::
363HasOneImplicitDefWithKnownVT(const CodeGenTarget &TargetInfo) const {
364  if (ImplicitDefs.empty()) return MVT::Other;
365
366  // Check to see if the first implicit def has a resolvable type.
367  Record *FirstImplicitDef = ImplicitDefs[0];
368  assert(FirstImplicitDef->isSubClassOf("Register"));
369  const std::vector<MVT::SimpleValueType> &RegVTs =
370    TargetInfo.getRegisterVTs(FirstImplicitDef);
371  if (RegVTs.size() == 1)
372    return RegVTs[0];
373  return MVT::Other;
374}
375
376
377/// FlattenAsmStringVariants - Flatten the specified AsmString to only
378/// include text from the specified variant, returning the new string.
379std::string CodeGenInstruction::
380FlattenAsmStringVariants(StringRef Cur, unsigned Variant) {
381  std::string Res = "";
382
383  for (;;) {
384    // Find the start of the next variant string.
385    size_t VariantsStart = 0;
386    for (size_t e = Cur.size(); VariantsStart != e; ++VariantsStart)
387      if (Cur[VariantsStart] == '{' &&
388          (VariantsStart == 0 || (Cur[VariantsStart-1] != '$' &&
389                                  Cur[VariantsStart-1] != '\\')))
390        break;
391
392    // Add the prefix to the result.
393    Res += Cur.slice(0, VariantsStart);
394    if (VariantsStart == Cur.size())
395      break;
396
397    ++VariantsStart; // Skip the '{'.
398
399    // Scan to the end of the variants string.
400    size_t VariantsEnd = VariantsStart;
401    unsigned NestedBraces = 1;
402    for (size_t e = Cur.size(); VariantsEnd != e; ++VariantsEnd) {
403      if (Cur[VariantsEnd] == '}' && Cur[VariantsEnd-1] != '\\') {
404        if (--NestedBraces == 0)
405          break;
406      } else if (Cur[VariantsEnd] == '{')
407        ++NestedBraces;
408    }
409
410    // Select the Nth variant (or empty).
411    StringRef Selection = Cur.slice(VariantsStart, VariantsEnd);
412    for (unsigned i = 0; i != Variant; ++i)
413      Selection = Selection.split('|').second;
414    Res += Selection.split('|').first;
415
416    assert(VariantsEnd != Cur.size() &&
417           "Unterminated variants in assembly string!");
418    Cur = Cur.substr(VariantsEnd + 1);
419  }
420
421  return Res;
422}
423
424
425//===----------------------------------------------------------------------===//
426/// CodeGenInstAlias Implementation
427//===----------------------------------------------------------------------===//
428
429/// tryAliasOpMatch - This is a helper function for the CodeGenInstAlias
430/// constructor.  It checks if an argument in an InstAlias pattern matches
431/// the corresponding operand of the instruction.  It returns true on a
432/// successful match, with ResOp set to the result operand to be used.
433bool CodeGenInstAlias::tryAliasOpMatch(DagInit *Result, unsigned AliasOpNo,
434                                       Record *InstOpRec, bool hasSubOps,
435                                       ArrayRef<SMLoc> Loc, CodeGenTarget &T,
436                                       ResultOperand &ResOp) {
437  Init *Arg = Result->getArg(AliasOpNo);
438  DefInit *ADI = dyn_cast<DefInit>(Arg);
439  Record *ResultRecord = ADI ? ADI->getDef() : nullptr;
440
441  if (ADI && ADI->getDef() == InstOpRec) {
442    // If the operand is a record, it must have a name, and the record type
443    // must match up with the instruction's argument type.
444    if (Result->getArgName(AliasOpNo).empty())
445      PrintFatalError(Loc, "result argument #" + Twine(AliasOpNo) +
446                           " must have a name!");
447    ResOp = ResultOperand(Result->getArgName(AliasOpNo), ResultRecord);
448    return true;
449  }
450
451  // For register operands, the source register class can be a subclass
452  // of the instruction register class, not just an exact match.
453  if (InstOpRec->isSubClassOf("RegisterOperand"))
454    InstOpRec = InstOpRec->getValueAsDef("RegClass");
455
456  if (ADI && ADI->getDef()->isSubClassOf("RegisterOperand"))
457    ADI = ADI->getDef()->getValueAsDef("RegClass")->getDefInit();
458
459  if (ADI && ADI->getDef()->isSubClassOf("RegisterClass")) {
460    if (!InstOpRec->isSubClassOf("RegisterClass"))
461      return false;
462    if (!T.getRegisterClass(InstOpRec)
463              .hasSubClass(&T.getRegisterClass(ADI->getDef())))
464      return false;
465    ResOp = ResultOperand(Result->getArgName(AliasOpNo), ResultRecord);
466    return true;
467  }
468
469  // Handle explicit registers.
470  if (ADI && ADI->getDef()->isSubClassOf("Register")) {
471    if (InstOpRec->isSubClassOf("OptionalDefOperand")) {
472      DagInit *DI = InstOpRec->getValueAsDag("MIOperandInfo");
473      // The operand info should only have a single (register) entry. We
474      // want the register class of it.
475      InstOpRec = cast<DefInit>(DI->getArg(0))->getDef();
476    }
477
478    if (!InstOpRec->isSubClassOf("RegisterClass"))
479      return false;
480
481    if (!T.getRegisterClass(InstOpRec)
482        .contains(T.getRegBank().getReg(ADI->getDef())))
483      PrintFatalError(Loc, "fixed register " + ADI->getDef()->getName() +
484                      " is not a member of the " + InstOpRec->getName() +
485                      " register class!");
486
487    if (!Result->getArgName(AliasOpNo).empty())
488      PrintFatalError(Loc, "result fixed register argument must "
489                      "not have a name!");
490
491    ResOp = ResultOperand(ResultRecord);
492    return true;
493  }
494
495  // Handle "zero_reg" for optional def operands.
496  if (ADI && ADI->getDef()->getName() == "zero_reg") {
497
498    // Check if this is an optional def.
499    // Tied operands where the source is a sub-operand of a complex operand
500    // need to represent both operands in the alias destination instruction.
501    // Allow zero_reg for the tied portion. This can and should go away once
502    // the MC representation of things doesn't use tied operands at all.
503    //if (!InstOpRec->isSubClassOf("OptionalDefOperand"))
504    //  throw TGError(Loc, "reg0 used for result that is not an "
505    //                "OptionalDefOperand!");
506
507    ResOp = ResultOperand(static_cast<Record*>(nullptr));
508    return true;
509  }
510
511  // Literal integers.
512  if (IntInit *II = dyn_cast<IntInit>(Arg)) {
513    if (hasSubOps || !InstOpRec->isSubClassOf("Operand"))
514      return false;
515    // Integer arguments can't have names.
516    if (!Result->getArgName(AliasOpNo).empty())
517      PrintFatalError(Loc, "result argument #" + Twine(AliasOpNo) +
518                      " must not have a name!");
519    ResOp = ResultOperand(II->getValue());
520    return true;
521  }
522
523  // If both are Operands with the same MVT, allow the conversion. It's
524  // up to the user to make sure the values are appropriate, just like
525  // for isel Pat's.
526  if (InstOpRec->isSubClassOf("Operand") &&
527      ADI->getDef()->isSubClassOf("Operand")) {
528    // FIXME: What other attributes should we check here? Identical
529    // MIOperandInfo perhaps?
530    if (InstOpRec->getValueInit("Type") != ADI->getDef()->getValueInit("Type"))
531      return false;
532    ResOp = ResultOperand(Result->getArgName(AliasOpNo), ADI->getDef());
533    return true;
534  }
535
536  return false;
537}
538
539unsigned CodeGenInstAlias::ResultOperand::getMINumOperands() const {
540  if (!isRecord())
541    return 1;
542
543  Record *Rec = getRecord();
544  if (!Rec->isSubClassOf("Operand"))
545    return 1;
546
547  DagInit *MIOpInfo = Rec->getValueAsDag("MIOperandInfo");
548  if (MIOpInfo->getNumArgs() == 0) {
549    // Unspecified, so it defaults to 1
550    return 1;
551  }
552
553  return MIOpInfo->getNumArgs();
554}
555
556CodeGenInstAlias::CodeGenInstAlias(Record *R, unsigned Variant,
557                                   CodeGenTarget &T)
558    : TheDef(R) {
559  Result = R->getValueAsDag("ResultInst");
560  AsmString = R->getValueAsString("AsmString");
561  AsmString = CodeGenInstruction::FlattenAsmStringVariants(AsmString, Variant);
562
563
564  // Verify that the root of the result is an instruction.
565  DefInit *DI = dyn_cast<DefInit>(Result->getOperator());
566  if (!DI || !DI->getDef()->isSubClassOf("Instruction"))
567    PrintFatalError(R->getLoc(),
568                    "result of inst alias should be an instruction");
569
570  ResultInst = &T.getInstruction(DI->getDef());
571
572  // NameClass - If argument names are repeated, we need to verify they have
573  // the same class.
574  StringMap<Record*> NameClass;
575  for (unsigned i = 0, e = Result->getNumArgs(); i != e; ++i) {
576    DefInit *ADI = dyn_cast<DefInit>(Result->getArg(i));
577    if (!ADI || Result->getArgName(i).empty())
578      continue;
579    // Verify we don't have something like: (someinst GR16:$foo, GR32:$foo)
580    // $foo can exist multiple times in the result list, but it must have the
581    // same type.
582    Record *&Entry = NameClass[Result->getArgName(i)];
583    if (Entry && Entry != ADI->getDef())
584      PrintFatalError(R->getLoc(), "result value $" + Result->getArgName(i) +
585                      " is both " + Entry->getName() + " and " +
586                      ADI->getDef()->getName() + "!");
587    Entry = ADI->getDef();
588  }
589
590  // Decode and validate the arguments of the result.
591  unsigned AliasOpNo = 0;
592  for (unsigned i = 0, e = ResultInst->Operands.size(); i != e; ++i) {
593
594    // Tied registers don't have an entry in the result dag unless they're part
595    // of a complex operand, in which case we include them anyways, as we
596    // don't have any other way to specify the whole operand.
597    if (ResultInst->Operands[i].MINumOperands == 1 &&
598        ResultInst->Operands[i].getTiedRegister() != -1)
599      continue;
600
601    if (AliasOpNo >= Result->getNumArgs())
602      PrintFatalError(R->getLoc(), "not enough arguments for instruction!");
603
604    Record *InstOpRec = ResultInst->Operands[i].Rec;
605    unsigned NumSubOps = ResultInst->Operands[i].MINumOperands;
606    ResultOperand ResOp(static_cast<int64_t>(0));
607    if (tryAliasOpMatch(Result, AliasOpNo, InstOpRec, (NumSubOps > 1),
608                        R->getLoc(), T, ResOp)) {
609      // If this is a simple operand, or a complex operand with a custom match
610      // class, then we can match is verbatim.
611      if (NumSubOps == 1 ||
612          (InstOpRec->getValue("ParserMatchClass") &&
613           InstOpRec->getValueAsDef("ParserMatchClass")
614             ->getValueAsString("Name") != "Imm")) {
615        ResultOperands.push_back(ResOp);
616        ResultInstOperandIndex.push_back(std::make_pair(i, -1));
617        ++AliasOpNo;
618
619      // Otherwise, we need to match each of the suboperands individually.
620      } else {
621         DagInit *MIOI = ResultInst->Operands[i].MIOperandInfo;
622         for (unsigned SubOp = 0; SubOp != NumSubOps; ++SubOp) {
623          Record *SubRec = cast<DefInit>(MIOI->getArg(SubOp))->getDef();
624
625          // Take care to instantiate each of the suboperands with the correct
626          // nomenclature: $foo.bar
627          ResultOperands.push_back(
628              ResultOperand(Result->getArgName(AliasOpNo) + "." +
629                            MIOI->getArgName(SubOp), SubRec));
630          ResultInstOperandIndex.push_back(std::make_pair(i, SubOp));
631         }
632         ++AliasOpNo;
633      }
634      continue;
635    }
636
637    // If the argument did not match the instruction operand, and the operand
638    // is composed of multiple suboperands, try matching the suboperands.
639    if (NumSubOps > 1) {
640      DagInit *MIOI = ResultInst->Operands[i].MIOperandInfo;
641      for (unsigned SubOp = 0; SubOp != NumSubOps; ++SubOp) {
642        if (AliasOpNo >= Result->getNumArgs())
643          PrintFatalError(R->getLoc(), "not enough arguments for instruction!");
644        Record *SubRec = cast<DefInit>(MIOI->getArg(SubOp))->getDef();
645        if (tryAliasOpMatch(Result, AliasOpNo, SubRec, false,
646                            R->getLoc(), T, ResOp)) {
647          ResultOperands.push_back(ResOp);
648          ResultInstOperandIndex.push_back(std::make_pair(i, SubOp));
649          ++AliasOpNo;
650        } else {
651          PrintFatalError(R->getLoc(), "result argument #" + Twine(AliasOpNo) +
652                        " does not match instruction operand class " +
653                        (SubOp == 0 ? InstOpRec->getName() :SubRec->getName()));
654        }
655      }
656      continue;
657    }
658    PrintFatalError(R->getLoc(), "result argument #" + Twine(AliasOpNo) +
659                    " does not match instruction operand class " +
660                    InstOpRec->getName());
661  }
662
663  if (AliasOpNo != Result->getNumArgs())
664    PrintFatalError(R->getLoc(), "too many operands for instruction!");
665}
666