utils/TableGen/CodeGenInstruction.cpp

   1 //===- CodeGenInstruction.cpp - CodeGen Instruction Class Wrapper ---------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 // This file implements the CodeGenInstruction class.
  10 //
  11 //===----------------------------------------------------------------------===//
  12
  13 #include "CodeGenInstruction.h"
  14 #include "CodeGenTarget.h"
  15 #include "llvm/ADT/STLExtras.h"
  16 #include "llvm/ADT/StringExtras.h"
  17 #include "llvm/ADT/StringMap.h"
  18 #include "llvm/TableGen/Error.h"
  19 #include "llvm/TableGen/Record.h"
  20 #include <set>
  21 using namespace llvm;
  22
  23 //===----------------------------------------------------------------------===//
  24 // CGIOperandList Implementation
  25 //===----------------------------------------------------------------------===//
  26
  27 CGIOperandList::CGIOperandList(Record *R) : TheDef(R) {
  28   isPredicable = false;
  29   hasOptionalDef = false;
  30   isVariadic = false;
  31
  32   DagInit *OutDI = R->getValueAsDag("OutOperandList");
  33
  34   if (DefInit *Init = dyn_cast<DefInit>(OutDI->getOperator())) {
  35     if (Init->getDef()->getName() != "outs")
  36       PrintFatalError(R->getLoc(),
  37                       R->getName() +
  38                           ": invalid def name for output list: use 'outs'");
  39   } else
  40     PrintFatalError(R->getLoc(),
  41                     R->getName() + ": invalid output list: use 'outs'");
  42
  43   NumDefs = OutDI->getNumArgs();
  44
  45   DagInit *InDI = R->getValueAsDag("InOperandList");
  46   if (DefInit *Init = dyn_cast<DefInit>(InDI->getOperator())) {
  47     if (Init->getDef()->getName() != "ins")
  48       PrintFatalError(R->getLoc(),
  49                       R->getName() +
  50                           ": invalid def name for input list: use 'ins'");
  51   } else
  52     PrintFatalError(R->getLoc(),
  53                     R->getName() + ": invalid input list: use 'ins'");
  54
  55   unsigned MIOperandNo = 0;
  56   std::set<std::string> OperandNames;
  57   unsigned e = InDI->getNumArgs() + OutDI->getNumArgs();
  58   OperandList.reserve(e);
  59   for (unsigned i = 0; i != e; ++i){
  60     Init *ArgInit;
  61     StringRef ArgName;
  62     if (i < NumDefs) {
  63       ArgInit = OutDI->getArg(i);
  64       ArgName = OutDI->getArgNameStr(i);
  65     } else {
  66       ArgInit = InDI->getArg(i-NumDefs);
  67       ArgName = InDI->getArgNameStr(i-NumDefs);
  68     }
  69
  70     DefInit *Arg = dyn_cast<DefInit>(ArgInit);
  71     if (!Arg)
  72       PrintFatalError(R->getLoc(), "Illegal operand for the '" + R->getName() +
  73                                        "' instruction!");
  74
  75     Record *Rec = Arg->getDef();
  76     std::string PrintMethod = "printOperand";
  77     std::string EncoderMethod;
  78     std::string OperandType = "OPERAND_UNKNOWN";
  79     std::string OperandNamespace = "MCOI";
  80     unsigned NumOps = 1;
  81     DagInit *MIOpInfo = nullptr;
  82     if (Rec->isSubClassOf("RegisterOperand")) {
  83       PrintMethod = Rec->getValueAsString("PrintMethod");
  84       OperandType = Rec->getValueAsString("OperandType");
  85       OperandNamespace = Rec->getValueAsString("OperandNamespace");
  86       EncoderMethod = Rec->getValueAsString("EncoderMethod");
  87     } else if (Rec->isSubClassOf("Operand")) {
  88       PrintMethod = Rec->getValueAsString("PrintMethod");
  89       OperandType = Rec->getValueAsString("OperandType");
  90       OperandNamespace = Rec->getValueAsString("OperandNamespace");
  91       // If there is an explicit encoder method, use it.
  92       EncoderMethod = Rec->getValueAsString("EncoderMethod");
  93       MIOpInfo = Rec->getValueAsDag("MIOperandInfo");
  94
  95       // Verify that MIOpInfo has an 'ops' root value.
  96       if (!isa<DefInit>(MIOpInfo->getOperator()) ||
  97           cast<DefInit>(MIOpInfo->getOperator())->getDef()->getName() != "ops")
  98         PrintFatalError(R->getLoc(),
  99                         "Bad value for MIOperandInfo in operand '" +
 100                             Rec->getName() + "'\n");
 101
 102       // If we have MIOpInfo, then we have #operands equal to number of entries
 103       // in MIOperandInfo.
 104       if (unsigned NumArgs = MIOpInfo->getNumArgs())
 105         NumOps = NumArgs;
 106
 107       if (Rec->isSubClassOf("PredicateOp"))
 108         isPredicable = true;
 109       else if (Rec->isSubClassOf("OptionalDefOperand"))
 110         hasOptionalDef = true;
 111     } else if (Rec->getName() == "variable_ops") {
 112       isVariadic = true;
 113       continue;
 114     } else if (Rec->isSubClassOf("RegisterClass")) {
 115       OperandType = "OPERAND_REGISTER";
 116     } else if (!Rec->isSubClassOf("PointerLikeRegClass") &&
 117                !Rec->isSubClassOf("unknown_class"))
 118       PrintFatalError(R->getLoc(), "Unknown operand class '" + Rec->getName() +
 119                                        "' in '" + R->getName() +
 120                                        "' instruction!");
 121
 122     // Check that the operand has a name and that it's unique.
 123     if (ArgName.empty())
 124       PrintFatalError(R->getLoc(), "In instruction '" + R->getName() +
 125                                        "', operand #" + Twine(i) +
 126                                        " has no name!");
 127     if (!OperandNames.insert(ArgName).second)
 128       PrintFatalError(R->getLoc(),
 129                       "In instruction '" + R->getName() + "', operand #" +
 130                           Twine(i) +
 131                           " has the same name as a previous operand!");
 132
 133     OperandList.emplace_back(Rec, ArgName, PrintMethod, EncoderMethod,
 134                              OperandNamespace + "::" + OperandType, MIOperandNo,
 135                              NumOps, MIOpInfo);
 136     MIOperandNo += NumOps;
 137   }
 138
 139
 140   // Make sure the constraints list for each operand is large enough to hold
 141   // constraint info, even if none is present.
 142   for (OperandInfo &OpInfo : OperandList)
 143     OpInfo.Constraints.resize(OpInfo.MINumOperands);
 144 }
 145
 146
 147 /// getOperandNamed - Return the index of the operand with the specified
 148 /// non-empty name.  If the instruction does not have an operand with the
 149 /// specified name, abort.
 150 ///
 151 unsigned CGIOperandList::getOperandNamed(StringRef Name) const {
 152   unsigned OpIdx;
 153   if (hasOperandNamed(Name, OpIdx))
 154     return OpIdx;
 155   PrintFatalError(TheDef->getLoc(), "'" + TheDef->getName() +
 156                                         "' does not have an operand named '$" +
 157                                         Name + "'!");
 158 }
 159
 160 /// hasOperandNamed - Query whether the instruction has an operand of the
 161 /// given name. If so, return true and set OpIdx to the index of the
 162 /// operand. Otherwise, return false.
 163 bool CGIOperandList::hasOperandNamed(StringRef Name, unsigned &OpIdx) const {
 164   assert(!Name.empty() && "Cannot search for operand with no name!");
 165   for (unsigned i = 0, e = OperandList.size(); i != e; ++i)
 166     if (OperandList[i].Name == Name) {
 167       OpIdx = i;
 168       return true;
 169     }
 170   return false;
 171 }
 172
 173 std::pair<unsigned,unsigned>
 174 CGIOperandList::ParseOperandName(const std::string &Op, bool AllowWholeOp) {
 175   if (Op.empty() || Op[0] != '$')
 176     PrintFatalError(TheDef->getLoc(),
 177                     TheDef->getName() + ": Illegal operand name: '" + Op + "'");
 178
 179   std::string OpName = Op.substr(1);
 180   std::string SubOpName;
 181
 182   // Check to see if this is $foo.bar.
 183   std::string::size_type DotIdx = OpName.find_first_of('.');
 184   if (DotIdx != std::string::npos) {
 185     SubOpName = OpName.substr(DotIdx+1);
 186     if (SubOpName.empty())
 187       PrintFatalError(TheDef->getLoc(),
 188                       TheDef->getName() +
 189                           ": illegal empty suboperand name in '" + Op + "'");
 190     OpName = OpName.substr(0, DotIdx);
 191   }
 192
 193   unsigned OpIdx = getOperandNamed(OpName);
 194
 195   if (SubOpName.empty()) {  // If no suboperand name was specified:
 196     // If one was needed, throw.
 197     if (OperandList[OpIdx].MINumOperands > 1 && !AllowWholeOp &&
 198         SubOpName.empty())
 199       PrintFatalError(TheDef->getLoc(),
 200                       TheDef->getName() +
 201                           ": Illegal to refer to"
 202                           " whole operand part of complex operand '" +
 203                           Op + "'");
 204
 205     // Otherwise, return the operand.
 206     return std::make_pair(OpIdx, 0U);
 207   }
 208
 209   // Find the suboperand number involved.
 210   DagInit *MIOpInfo = OperandList[OpIdx].MIOperandInfo;
 211   if (!MIOpInfo)
 212     PrintFatalError(TheDef->getLoc(), TheDef->getName() +
 213                                           ": unknown suboperand name in '" +
 214                                           Op + "'");
 215
 216   // Find the operand with the right name.
 217   for (unsigned i = 0, e = MIOpInfo->getNumArgs(); i != e; ++i)
 218     if (MIOpInfo->getArgNameStr(i) == SubOpName)
 219       return std::make_pair(OpIdx, i);
 220
 221   // Otherwise, didn't find it!
 222   PrintFatalError(TheDef->getLoc(), TheDef->getName() +
 223                                         ": unknown suboperand name in '" + Op +
 224                                         "'");
 225   return std::make_pair(0U, 0U);
 226 }
 227
 228 static void ParseConstraint(const std::string &CStr, CGIOperandList &Ops,
 229                             Record *Rec) {
 230   // EARLY_CLOBBER: @early $reg
 231   std::string::size_type wpos = CStr.find_first_of(" \t");
 232   std::string::size_type start = CStr.find_first_not_of(" \t");
 233   std::string Tok = CStr.substr(start, wpos - start);
 234   if (Tok == "@earlyclobber") {
 235     std::string Name = CStr.substr(wpos+1);
 236     wpos = Name.find_first_not_of(" \t");
 237     if (wpos == std::string::npos)
 238       PrintFatalError(
 239         Rec->getLoc(), "Illegal format for @earlyclobber constraint in '" +
 240         Rec->getName() + "': '" + CStr + "'");
 241     Name = Name.substr(wpos);
 242     std::pair<unsigned,unsigned> Op = Ops.ParseOperandName(Name, false);
 243
 244     // Build the string for the operand
 245     if (!Ops[Op.first].Constraints[Op.second].isNone())
 246       PrintFatalError(
 247         Rec->getLoc(), "Operand '" + Name + "' of '" + Rec->getName() +
 248         "' cannot have multiple constraints!");
 249     Ops[Op.first].Constraints[Op.second] =
 250     CGIOperandList::ConstraintInfo::getEarlyClobber();
 251     return;
 252   }
 253
 254   // Only other constraint is "TIED_TO" for now.
 255   std::string::size_type pos = CStr.find_first_of('=');
 256   if (pos == std::string::npos)
 257     PrintFatalError(
 258       Rec->getLoc(), "Unrecognized constraint '" + CStr +
 259       "' in '" + Rec->getName() + "'");
 260   start = CStr.find_first_not_of(" \t");
 261
 262   // TIED_TO: $src1 = $dst
 263   wpos = CStr.find_first_of(" \t", start);
 264   if (wpos == std::string::npos || wpos > pos)
 265     PrintFatalError(
 266       Rec->getLoc(), "Illegal format for tied-to constraint in '" +
 267       Rec->getName() + "': '" + CStr + "'");
 268   std::string LHSOpName = StringRef(CStr).substr(start, wpos - start);
 269   std::pair<unsigned,unsigned> LHSOp = Ops.ParseOperandName(LHSOpName, false);
 270
 271   wpos = CStr.find_first_not_of(" \t", pos + 1);
 272   if (wpos == std::string::npos)
 273     PrintFatalError(
 274       Rec->getLoc(), "Illegal format for tied-to constraint: '" + CStr + "'");
 275
 276   std::string RHSOpName = StringRef(CStr).substr(wpos);
 277   std::pair<unsigned,unsigned> RHSOp = Ops.ParseOperandName(RHSOpName, false);
 278
 279   // Sort the operands into order, which should put the output one
 280   // first. But keep the original order, for use in diagnostics.
 281   bool FirstIsDest = (LHSOp < RHSOp);
 282   std::pair<unsigned,unsigned> DestOp = (FirstIsDest ? LHSOp : RHSOp);
 283   StringRef DestOpName = (FirstIsDest ? LHSOpName : RHSOpName);
 284   std::pair<unsigned,unsigned> SrcOp = (FirstIsDest ? RHSOp : LHSOp);
 285   StringRef SrcOpName = (FirstIsDest ? RHSOpName : LHSOpName);
 286
 287   // Ensure one operand is a def and the other is a use.
 288   if (DestOp.first >= Ops.NumDefs)
 289     PrintFatalError(
 290       Rec->getLoc(), "Input operands '" + LHSOpName + "' and '" + RHSOpName +
 291       "' of '" + Rec->getName() + "' cannot be tied!");
 292   if (SrcOp.first < Ops.NumDefs)
 293     PrintFatalError(
 294       Rec->getLoc(), "Output operands '" + LHSOpName + "' and '" + RHSOpName +
 295       "' of '" + Rec->getName() + "' cannot be tied!");
 296
 297   // The constraint has to go on the operand with higher index, i.e.
 298   // the source one. Check there isn't another constraint there
 299   // already.
 300   if (!Ops[SrcOp.first].Constraints[SrcOp.second].isNone())
 301     PrintFatalError(
 302       Rec->getLoc(), "Operand '" + SrcOpName + "' of '" + Rec->getName() +
 303       "' cannot have multiple constraints!");
 304
 305   unsigned DestFlatOpNo = Ops.getFlattenedOperandNumber(DestOp);
 306   auto NewConstraint = CGIOperandList::ConstraintInfo::getTied(DestFlatOpNo);
 307
 308   // Check that the earlier operand is not the target of another tie
 309   // before making it the target of this one.
 310   for (const CGIOperandList::OperandInfo &Op : Ops) {
 311     for (unsigned i = 0; i < Op.MINumOperands; i++)
 312       if (Op.Constraints[i] == NewConstraint)
 313         PrintFatalError(
 314           Rec->getLoc(), "Operand '" + DestOpName + "' of '" + Rec->getName() +
 315           "' cannot have multiple operands tied to it!");
 316   }
 317
 318   Ops[SrcOp.first].Constraints[SrcOp.second] = NewConstraint;
 319 }
 320
 321 static void ParseConstraints(const std::string &CStr, CGIOperandList &Ops,
 322                              Record *Rec) {
 323   if (CStr.empty()) return;
 324
 325   const std::string delims(",");
 326   std::string::size_type bidx, eidx;
 327
 328   bidx = CStr.find_first_not_of(delims);
 329   while (bidx != std::string::npos) {
 330     eidx = CStr.find_first_of(delims, bidx);
 331     if (eidx == std::string::npos)
 332       eidx = CStr.length();
 333
 334     ParseConstraint(CStr.substr(bidx, eidx - bidx), Ops, Rec);
 335     bidx = CStr.find_first_not_of(delims, eidx);
 336   }
 337 }
 338
 339 void CGIOperandList::ProcessDisableEncoding(std::string DisableEncoding) {
 340   while (1) {
 341     std::pair<StringRef, StringRef> P = getToken(DisableEncoding, " ,\t");
 342     std::string OpName = P.first;
 343     DisableEncoding = P.second;
 344     if (OpName.empty()) break;
 345
 346     // Figure out which operand this is.
 347     std::pair<unsigned,unsigned> Op = ParseOperandName(OpName, false);
 348
 349     // Mark the operand as not-to-be encoded.
 350     if (Op.second >= OperandList[Op.first].DoNotEncode.size())
 351       OperandList[Op.first].DoNotEncode.resize(Op.second+1);
 352     OperandList[Op.first].DoNotEncode[Op.second] = true;
 353   }
 354
 355 }
 356
 357 //===----------------------------------------------------------------------===//
 358 // CodeGenInstruction Implementation
 359 //===----------------------------------------------------------------------===//
 360
 361 CodeGenInstruction::CodeGenInstruction(Record *R)
 362   : TheDef(R), Operands(R), InferredFrom(nullptr) {
 363   Namespace = R->getValueAsString("Namespace");
 364   AsmString = R->getValueAsString("AsmString");
 365
 366   isPreISelOpcode = R->getValueAsBit("isPreISelOpcode");
 367   isReturn     = R->getValueAsBit("isReturn");
 368   isEHScopeReturn = R->getValueAsBit("isEHScopeReturn");
 369   isBranch     = R->getValueAsBit("isBranch");
 370   isIndirectBranch = R->getValueAsBit("isIndirectBranch");
 371   isCompare    = R->getValueAsBit("isCompare");
 372   isMoveImm    = R->getValueAsBit("isMoveImm");
 373   isMoveReg    = R->getValueAsBit("isMoveReg");
 374   isBitcast    = R->getValueAsBit("isBitcast");
 375   isSelect     = R->getValueAsBit("isSelect");
 376   isBarrier    = R->getValueAsBit("isBarrier");
 377   isCall       = R->getValueAsBit("isCall");
 378   isAdd        = R->getValueAsBit("isAdd");
 379   isTrap       = R->getValueAsBit("isTrap");
 380   canFoldAsLoad = R->getValueAsBit("canFoldAsLoad");
 381   isPredicable = !R->getValueAsBit("isUnpredicable") && (
 382       Operands.isPredicable || R->getValueAsBit("isPredicable"));
 383   isConvertibleToThreeAddress = R->getValueAsBit("isConvertibleToThreeAddress");
 384   isCommutable = R->getValueAsBit("isCommutable");
 385   isTerminator = R->getValueAsBit("isTerminator");
 386   isReMaterializable = R->getValueAsBit("isReMaterializable");
 387   hasDelaySlot = R->getValueAsBit("hasDelaySlot");
 388   usesCustomInserter = R->getValueAsBit("usesCustomInserter");
 389   hasPostISelHook = R->getValueAsBit("hasPostISelHook");
 390   hasCtrlDep   = R->getValueAsBit("hasCtrlDep");
 391   isNotDuplicable = R->getValueAsBit("isNotDuplicable");
 392   isRegSequence = R->getValueAsBit("isRegSequence");
 393   isExtractSubreg = R->getValueAsBit("isExtractSubreg");
 394   isInsertSubreg = R->getValueAsBit("isInsertSubreg");
 395   isConvergent = R->getValueAsBit("isConvergent");
 396   hasNoSchedulingInfo = R->getValueAsBit("hasNoSchedulingInfo");
 397   FastISelShouldIgnore = R->getValueAsBit("FastISelShouldIgnore");
 398   variadicOpsAreDefs = R->getValueAsBit("variadicOpsAreDefs");
 399
 400   bool Unset;
 401   mayLoad      = R->getValueAsBitOrUnset("mayLoad", Unset);
 402   mayLoad_Unset = Unset;
 403   mayStore     = R->getValueAsBitOrUnset("mayStore", Unset);
 404   mayStore_Unset = Unset;
 405   mayRaiseFPException = R->getValueAsBit("mayRaiseFPException");
 406   hasSideEffects = R->getValueAsBitOrUnset("hasSideEffects", Unset);
 407   hasSideEffects_Unset = Unset;
 408
 409   isAsCheapAsAMove = R->getValueAsBit("isAsCheapAsAMove");
 410   hasExtraSrcRegAllocReq = R->getValueAsBit("hasExtraSrcRegAllocReq");
 411   hasExtraDefRegAllocReq = R->getValueAsBit("hasExtraDefRegAllocReq");
 412   isCodeGenOnly = R->getValueAsBit("isCodeGenOnly");
 413   isPseudo = R->getValueAsBit("isPseudo");
 414   ImplicitDefs = R->getValueAsListOfDefs("Defs");
 415   ImplicitUses = R->getValueAsListOfDefs("Uses");
 416
 417   // This flag is only inferred from the pattern.
 418   hasChain = false;
 419   hasChain_Inferred = false;
 420
 421   // Parse Constraints.
 422   ParseConstraints(R->getValueAsString("Constraints"), Operands, R);
 423
 424   // Parse the DisableEncoding field.
 425   Operands.ProcessDisableEncoding(R->getValueAsString("DisableEncoding"));
 426
 427   // First check for a ComplexDeprecationPredicate.
 428   if (R->getValue("ComplexDeprecationPredicate")) {
 429     HasComplexDeprecationPredicate = true;
 430     DeprecatedReason = R->getValueAsString("ComplexDeprecationPredicate");
 431   } else if (RecordVal *Dep = R->getValue("DeprecatedFeatureMask")) {
 432     // Check if we have a Subtarget feature mask.
 433     HasComplexDeprecationPredicate = false;
 434     DeprecatedReason = Dep->getValue()->getAsString();
 435   } else {
 436     // This instruction isn't deprecated.
 437     HasComplexDeprecationPredicate = false;
 438     DeprecatedReason = "";
 439   }
 440 }
 441
 442 /// HasOneImplicitDefWithKnownVT - If the instruction has at least one
 443 /// implicit def and it has a known VT, return the VT, otherwise return
 444 /// MVT::Other.
 445 MVT::SimpleValueType CodeGenInstruction::
 446 HasOneImplicitDefWithKnownVT(const CodeGenTarget &TargetInfo) const {
 447   if (ImplicitDefs.empty()) return MVT::Other;
 448
 449   // Check to see if the first implicit def has a resolvable type.
 450   Record *FirstImplicitDef = ImplicitDefs[0];
 451   assert(FirstImplicitDef->isSubClassOf("Register"));
 452   const std::vector<ValueTypeByHwMode> &RegVTs =
 453     TargetInfo.getRegisterVTs(FirstImplicitDef);
 454   if (RegVTs.size() == 1 && RegVTs[0].isSimple())
 455     return RegVTs[0].getSimple().SimpleTy;
 456   return MVT::Other;
 457 }
 458
 459
 460 /// FlattenAsmStringVariants - Flatten the specified AsmString to only
 461 /// include text from the specified variant, returning the new string.
 462 std::string CodeGenInstruction::
 463 FlattenAsmStringVariants(StringRef Cur, unsigned Variant) {
 464   std::string Res = "";
 465
 466   for (;;) {
 467     // Find the start of the next variant string.
 468     size_t VariantsStart = 0;
 469     for (size_t e = Cur.size(); VariantsStart != e; ++VariantsStart)
 470       if (Cur[VariantsStart] == '{' &&
 471           (VariantsStart == 0 || (Cur[VariantsStart-1] != '$' &&
 472                                   Cur[VariantsStart-1] != '\\')))
 473         break;
 474
 475     // Add the prefix to the result.
 476     Res += Cur.slice(0, VariantsStart);
 477     if (VariantsStart == Cur.size())
 478       break;
 479
 480     ++VariantsStart; // Skip the '{'.
 481
 482     // Scan to the end of the variants string.
 483     size_t VariantsEnd = VariantsStart;
 484     unsigned NestedBraces = 1;
 485     for (size_t e = Cur.size(); VariantsEnd != e; ++VariantsEnd) {
 486       if (Cur[VariantsEnd] == '}' && Cur[VariantsEnd-1] != '\\') {
 487         if (--NestedBraces == 0)
 488           break;
 489       } else if (Cur[VariantsEnd] == '{')
 490         ++NestedBraces;
 491     }
 492
 493     // Select the Nth variant (or empty).
 494     StringRef Selection = Cur.slice(VariantsStart, VariantsEnd);
 495     for (unsigned i = 0; i != Variant; ++i)
 496       Selection = Selection.split('|').second;
 497     Res += Selection.split('|').first;
 498
 499     assert(VariantsEnd != Cur.size() &&
 500            "Unterminated variants in assembly string!");
 501     Cur = Cur.substr(VariantsEnd + 1);
 502   }
 503
 504   return Res;
 505 }
 506
 507 bool CodeGenInstruction::isOperandAPointer(unsigned i) const {
 508   if (DagInit *ConstraintList = TheDef->getValueAsDag("InOperandList")) {
 509     if (i < ConstraintList->getNumArgs()) {
 510       if (DefInit *Constraint = dyn_cast<DefInit>(ConstraintList->getArg(i))) {
 511         return Constraint->getDef()->isSubClassOf("TypedOperand") &&
 512                Constraint->getDef()->getValueAsBit("IsPointer");
 513       }
 514     }
 515   }
 516   return false;
 517 }
 518
 519 //===----------------------------------------------------------------------===//
 520 /// CodeGenInstAlias Implementation
 521 //===----------------------------------------------------------------------===//
 522
 523 /// tryAliasOpMatch - This is a helper function for the CodeGenInstAlias
 524 /// constructor.  It checks if an argument in an InstAlias pattern matches
 525 /// the corresponding operand of the instruction.  It returns true on a
 526 /// successful match, with ResOp set to the result operand to be used.
 527 bool CodeGenInstAlias::tryAliasOpMatch(DagInit *Result, unsigned AliasOpNo,
 528                                        Record *InstOpRec, bool hasSubOps,
 529                                        ArrayRef<SMLoc> Loc, CodeGenTarget &T,
 530                                        ResultOperand &ResOp) {
 531   Init *Arg = Result->getArg(AliasOpNo);
 532   DefInit *ADI = dyn_cast<DefInit>(Arg);
 533   Record *ResultRecord = ADI ? ADI->getDef() : nullptr;
 534
 535   if (ADI && ADI->getDef() == InstOpRec) {
 536     // If the operand is a record, it must have a name, and the record type
 537     // must match up with the instruction's argument type.
 538     if (!Result->getArgName(AliasOpNo))
 539       PrintFatalError(Loc, "result argument #" + Twine(AliasOpNo) +
 540                            " must have a name!");
 541     ResOp = ResultOperand(Result->getArgNameStr(AliasOpNo), ResultRecord);
 542     return true;
 543   }
 544
 545   // For register operands, the source register class can be a subclass
 546   // of the instruction register class, not just an exact match.
 547   if (InstOpRec->isSubClassOf("RegisterOperand"))
 548     InstOpRec = InstOpRec->getValueAsDef("RegClass");
 549
 550   if (ADI && ADI->getDef()->isSubClassOf("RegisterOperand"))
 551     ADI = ADI->getDef()->getValueAsDef("RegClass")->getDefInit();
 552
 553   if (ADI && ADI->getDef()->isSubClassOf("RegisterClass")) {
 554     if (!InstOpRec->isSubClassOf("RegisterClass"))
 555       return false;
 556     if (!T.getRegisterClass(InstOpRec)
 557               .hasSubClass(&T.getRegisterClass(ADI->getDef())))
 558       return false;
 559     ResOp = ResultOperand(Result->getArgNameStr(AliasOpNo), ResultRecord);
 560     return true;
 561   }
 562
 563   // Handle explicit registers.
 564   if (ADI && ADI->getDef()->isSubClassOf("Register")) {
 565     if (InstOpRec->isSubClassOf("OptionalDefOperand")) {
 566       DagInit *DI = InstOpRec->getValueAsDag("MIOperandInfo");
 567       // The operand info should only have a single (register) entry. We
 568       // want the register class of it.
 569       InstOpRec = cast<DefInit>(DI->getArg(0))->getDef();
 570     }
 571
 572     if (!InstOpRec->isSubClassOf("RegisterClass"))
 573       return false;
 574
 575     if (!T.getRegisterClass(InstOpRec)
 576         .contains(T.getRegBank().getReg(ADI->getDef())))
 577       PrintFatalError(Loc, "fixed register " + ADI->getDef()->getName() +
 578                       " is not a member of the " + InstOpRec->getName() +
 579                       " register class!");
 580
 581     if (Result->getArgName(AliasOpNo))
 582       PrintFatalError(Loc, "result fixed register argument must "
 583                       "not have a name!");
 584
 585     ResOp = ResultOperand(ResultRecord);
 586     return true;
 587   }
 588
 589   // Handle "zero_reg" for optional def operands.
 590   if (ADI && ADI->getDef()->getName() == "zero_reg") {
 591
 592     // Check if this is an optional def.
 593     // Tied operands where the source is a sub-operand of a complex operand
 594     // need to represent both operands in the alias destination instruction.
 595     // Allow zero_reg for the tied portion. This can and should go away once
 596     // the MC representation of things doesn't use tied operands at all.
 597     //if (!InstOpRec->isSubClassOf("OptionalDefOperand"))
 598     //  throw TGError(Loc, "reg0 used for result that is not an "
 599     //                "OptionalDefOperand!");
 600
 601     ResOp = ResultOperand(static_cast<Record*>(nullptr));
 602     return true;
 603   }
 604
 605   // Literal integers.
 606   if (IntInit *II = dyn_cast<IntInit>(Arg)) {
 607     if (hasSubOps || !InstOpRec->isSubClassOf("Operand"))
 608       return false;
 609     // Integer arguments can't have names.
 610     if (Result->getArgName(AliasOpNo))
 611       PrintFatalError(Loc, "result argument #" + Twine(AliasOpNo) +
 612                       " must not have a name!");
 613     ResOp = ResultOperand(II->getValue());
 614     return true;
 615   }
 616
 617   // Bits<n> (also used for 0bxx literals)
 618   if (BitsInit *BI = dyn_cast<BitsInit>(Arg)) {
 619     if (hasSubOps || !InstOpRec->isSubClassOf("Operand"))
 620       return false;
 621     if (!BI->isComplete())
 622       return false;
 623     // Convert the bits init to an integer and use that for the result.
 624     IntInit *II =
 625       dyn_cast_or_null<IntInit>(BI->convertInitializerTo(IntRecTy::get()));
 626     if (!II)
 627       return false;
 628     ResOp = ResultOperand(II->getValue());
 629     return true;
 630   }
 631
 632   // If both are Operands with the same MVT, allow the conversion. It's
 633   // up to the user to make sure the values are appropriate, just like
 634   // for isel Pat's.
 635   if (InstOpRec->isSubClassOf("Operand") && ADI &&
 636       ADI->getDef()->isSubClassOf("Operand")) {
 637     // FIXME: What other attributes should we check here? Identical
 638     // MIOperandInfo perhaps?
 639     if (InstOpRec->getValueInit("Type") != ADI->getDef()->getValueInit("Type"))
 640       return false;
 641     ResOp = ResultOperand(Result->getArgNameStr(AliasOpNo), ADI->getDef());
 642     return true;
 643   }
 644
 645   return false;
 646 }
 647
 648 unsigned CodeGenInstAlias::ResultOperand::getMINumOperands() const {
 649   if (!isRecord())
 650     return 1;
 651
 652   Record *Rec = getRecord();
 653   if (!Rec->isSubClassOf("Operand"))
 654     return 1;
 655
 656   DagInit *MIOpInfo = Rec->getValueAsDag("MIOperandInfo");
 657   if (MIOpInfo->getNumArgs() == 0) {
 658     // Unspecified, so it defaults to 1
 659     return 1;
 660   }
 661
 662   return MIOpInfo->getNumArgs();
 663 }
 664
 665 CodeGenInstAlias::CodeGenInstAlias(Record *R, CodeGenTarget &T)
 666     : TheDef(R) {
 667   Result = R->getValueAsDag("ResultInst");
 668   AsmString = R->getValueAsString("AsmString");
 669
 670
 671   // Verify that the root of the result is an instruction.
 672   DefInit *DI = dyn_cast<DefInit>(Result->getOperator());
 673   if (!DI || !DI->getDef()->isSubClassOf("Instruction"))
 674     PrintFatalError(R->getLoc(),
 675                     "result of inst alias should be an instruction");
 676
 677   ResultInst = &T.getInstruction(DI->getDef());
 678
 679   // NameClass - If argument names are repeated, we need to verify they have
 680   // the same class.
 681   StringMap<Record*> NameClass;
 682   for (unsigned i = 0, e = Result->getNumArgs(); i != e; ++i) {
 683     DefInit *ADI = dyn_cast<DefInit>(Result->getArg(i));
 684     if (!ADI || !Result->getArgName(i))
 685       continue;
 686     // Verify we don't have something like: (someinst GR16:$foo, GR32:$foo)
 687     // $foo can exist multiple times in the result list, but it must have the
 688     // same type.
 689     Record *&Entry = NameClass[Result->getArgNameStr(i)];
 690     if (Entry && Entry != ADI->getDef())
 691       PrintFatalError(R->getLoc(), "result value $" + Result->getArgNameStr(i) +
 692                       " is both " + Entry->getName() + " and " +
 693                       ADI->getDef()->getName() + "!");
 694     Entry = ADI->getDef();
 695   }
 696
 697   // Decode and validate the arguments of the result.
 698   unsigned AliasOpNo = 0;
 699   for (unsigned i = 0, e = ResultInst->Operands.size(); i != e; ++i) {
 700
 701     // Tied registers don't have an entry in the result dag unless they're part
 702     // of a complex operand, in which case we include them anyways, as we
 703     // don't have any other way to specify the whole operand.
 704     if (ResultInst->Operands[i].MINumOperands == 1 &&
 705         ResultInst->Operands[i].getTiedRegister() != -1) {
 706       // Tied operands of different RegisterClass should be explicit within an
 707       // instruction's syntax and so cannot be skipped.
 708       int TiedOpNum = ResultInst->Operands[i].getTiedRegister();
 709       if (ResultInst->Operands[i].Rec->getName() ==
 710           ResultInst->Operands[TiedOpNum].Rec->getName())
 711         continue;
 712     }
 713
 714     if (AliasOpNo >= Result->getNumArgs())
 715       PrintFatalError(R->getLoc(), "not enough arguments for instruction!");
 716
 717     Record *InstOpRec = ResultInst->Operands[i].Rec;
 718     unsigned NumSubOps = ResultInst->Operands[i].MINumOperands;
 719     ResultOperand ResOp(static_cast<int64_t>(0));
 720     if (tryAliasOpMatch(Result, AliasOpNo, InstOpRec, (NumSubOps > 1),
 721                         R->getLoc(), T, ResOp)) {
 722       // If this is a simple operand, or a complex operand with a custom match
 723       // class, then we can match is verbatim.
 724       if (NumSubOps == 1 ||
 725           (InstOpRec->getValue("ParserMatchClass") &&
 726            InstOpRec->getValueAsDef("ParserMatchClass")
 727              ->getValueAsString("Name") != "Imm")) {
 728         ResultOperands.push_back(ResOp);
 729         ResultInstOperandIndex.push_back(std::make_pair(i, -1));
 730         ++AliasOpNo;
 731
 732       // Otherwise, we need to match each of the suboperands individually.
 733       } else {
 734          DagInit *MIOI = ResultInst->Operands[i].MIOperandInfo;
 735          for (unsigned SubOp = 0; SubOp != NumSubOps; ++SubOp) {
 736           Record *SubRec = cast<DefInit>(MIOI->getArg(SubOp))->getDef();
 737
 738           // Take care to instantiate each of the suboperands with the correct
 739           // nomenclature: $foo.bar
 740           ResultOperands.emplace_back(
 741             Result->getArgName(AliasOpNo)->getAsUnquotedString() + "." +
 742             MIOI->getArgName(SubOp)->getAsUnquotedString(), SubRec);
 743           ResultInstOperandIndex.push_back(std::make_pair(i, SubOp));
 744          }
 745          ++AliasOpNo;
 746       }
 747       continue;
 748     }
 749
 750     // If the argument did not match the instruction operand, and the operand
 751     // is composed of multiple suboperands, try matching the suboperands.
 752     if (NumSubOps > 1) {
 753       DagInit *MIOI = ResultInst->Operands[i].MIOperandInfo;
 754       for (unsigned SubOp = 0; SubOp != NumSubOps; ++SubOp) {
 755         if (AliasOpNo >= Result->getNumArgs())
 756           PrintFatalError(R->getLoc(), "not enough arguments for instruction!");
 757         Record *SubRec = cast<DefInit>(MIOI->getArg(SubOp))->getDef();
 758         if (tryAliasOpMatch(Result, AliasOpNo, SubRec, false,
 759                             R->getLoc(), T, ResOp)) {
 760           ResultOperands.push_back(ResOp);
 761           ResultInstOperandIndex.push_back(std::make_pair(i, SubOp));
 762           ++AliasOpNo;
 763         } else {
 764           PrintFatalError(R->getLoc(), "result argument #" + Twine(AliasOpNo) +
 765                         " does not match instruction operand class " +
 766                         (SubOp == 0 ? InstOpRec->getName() :SubRec->getName()));
 767         }
 768       }
 769       continue;
 770     }
 771     PrintFatalError(R->getLoc(), "result argument #" + Twine(AliasOpNo) +
 772                     " does not match instruction operand class " +
 773                     InstOpRec->getName());
 774   }
 775
 776   if (AliasOpNo != Result->getNumArgs())
 777     PrintFatalError(R->getLoc(), "too many operands for instruction!");
 778 }