1//===- DAGISelMatcherGen.cpp - Matcher generator --------------------------===// 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#include "DAGISelMatcher.h" 11#include "CodeGenDAGPatterns.h" 12#include "CodeGenRegisters.h" 13#include "llvm/ADT/DenseMap.h" 14#include "llvm/ADT/SmallVector.h" 15#include "llvm/ADT/StringMap.h" 16#include "llvm/TableGen/Error.h" 17#include "llvm/TableGen/Record.h" 18#include <utility> 19using namespace llvm; 20 21 22/// getRegisterValueType - Look up and return the ValueType of the specified 23/// register. If the register is a member of multiple register classes which 24/// have different associated types, return MVT::Other. 25static MVT::SimpleValueType getRegisterValueType(Record *R, 26 const CodeGenTarget &T) { 27 bool FoundRC = false; 28 MVT::SimpleValueType VT = MVT::Other; 29 const CodeGenRegister *Reg = T.getRegBank().getReg(R); 30 31 for (const auto &RC : T.getRegBank().getRegClasses()) { 32 if (!RC.contains(Reg)) 33 continue; 34 35 if (!FoundRC) { 36 FoundRC = true; 37 VT = RC.getValueTypeNum(0); 38 continue; 39 } 40 41 // If this occurs in multiple register classes, they all have to agree. 42 assert(VT == RC.getValueTypeNum(0)); 43 } 44 return VT; 45} 46 47 48namespace { 49 class MatcherGen { 50 const PatternToMatch &Pattern; 51 const CodeGenDAGPatterns &CGP; 52 53 /// PatWithNoTypes - This is a clone of Pattern.getSrcPattern() that starts 54 /// out with all of the types removed. This allows us to insert type checks 55 /// as we scan the tree. 56 TreePatternNode *PatWithNoTypes; 57 58 /// VariableMap - A map from variable names ('$dst') to the recorded operand 59 /// number that they were captured as. These are biased by 1 to make 60 /// insertion easier. 61 StringMap<unsigned> VariableMap; 62 63 /// This maintains the recorded operand number that OPC_CheckComplexPattern 64 /// drops each sub-operand into. We don't want to insert these into 65 /// VariableMap because that leads to identity checking if they are 66 /// encountered multiple times. Biased by 1 like VariableMap for 67 /// consistency. 68 StringMap<unsigned> NamedComplexPatternOperands; 69 70 /// NextRecordedOperandNo - As we emit opcodes to record matched values in 71 /// the RecordedNodes array, this keeps track of which slot will be next to 72 /// record into. 73 unsigned NextRecordedOperandNo; 74 75 /// MatchedChainNodes - This maintains the position in the recorded nodes 76 /// array of all of the recorded input nodes that have chains. 77 SmallVector<unsigned, 2> MatchedChainNodes; 78 79 /// MatchedGlueResultNodes - This maintains the position in the recorded 80 /// nodes array of all of the recorded input nodes that have glue results. 81 SmallVector<unsigned, 2> MatchedGlueResultNodes; 82 83 /// MatchedComplexPatterns - This maintains a list of all of the 84 /// ComplexPatterns that we need to check. The second element of each pair 85 /// is the recorded operand number of the input node. 86 SmallVector<std::pair<const TreePatternNode*, 87 unsigned>, 2> MatchedComplexPatterns; 88 89 /// PhysRegInputs - List list has an entry for each explicitly specified 90 /// physreg input to the pattern. The first elt is the Register node, the 91 /// second is the recorded slot number the input pattern match saved it in. 92 SmallVector<std::pair<Record*, unsigned>, 2> PhysRegInputs; 93 94 /// Matcher - This is the top level of the generated matcher, the result. 95 Matcher *TheMatcher; 96 97 /// CurPredicate - As we emit matcher nodes, this points to the latest check 98 /// which should have future checks stuck into its Next position. 99 Matcher *CurPredicate; 100 public: 101 MatcherGen(const PatternToMatch &pattern, const CodeGenDAGPatterns &cgp); 102 103 ~MatcherGen() { 104 delete PatWithNoTypes; 105 } 106 107 bool EmitMatcherCode(unsigned Variant); 108 void EmitResultCode(); 109 110 Matcher *GetMatcher() const { return TheMatcher; } 111 private: 112 void AddMatcher(Matcher *NewNode); 113 void InferPossibleTypes(); 114 115 // Matcher Generation. 116 void EmitMatchCode(const TreePatternNode *N, TreePatternNode *NodeNoTypes); 117 void EmitLeafMatchCode(const TreePatternNode *N); 118 void EmitOperatorMatchCode(const TreePatternNode *N, 119 TreePatternNode *NodeNoTypes); 120 121 /// If this is the first time a node with unique identifier Name has been 122 /// seen, record it. Otherwise, emit a check to make sure this is the same 123 /// node. Returns true if this is the first encounter. 124 bool recordUniqueNode(std::string Name); 125 126 // Result Code Generation. 127 unsigned getNamedArgumentSlot(StringRef Name) { 128 unsigned VarMapEntry = VariableMap[Name]; 129 assert(VarMapEntry != 0 && 130 "Variable referenced but not defined and not caught earlier!"); 131 return VarMapEntry-1; 132 } 133 134 /// GetInstPatternNode - Get the pattern for an instruction. 135 const TreePatternNode *GetInstPatternNode(const DAGInstruction &Ins, 136 const TreePatternNode *N); 137 138 void EmitResultOperand(const TreePatternNode *N, 139 SmallVectorImpl<unsigned> &ResultOps); 140 void EmitResultOfNamedOperand(const TreePatternNode *N, 141 SmallVectorImpl<unsigned> &ResultOps); 142 void EmitResultLeafAsOperand(const TreePatternNode *N, 143 SmallVectorImpl<unsigned> &ResultOps); 144 void EmitResultInstructionAsOperand(const TreePatternNode *N, 145 SmallVectorImpl<unsigned> &ResultOps); 146 void EmitResultSDNodeXFormAsOperand(const TreePatternNode *N, 147 SmallVectorImpl<unsigned> &ResultOps); 148 }; 149 150} // end anon namespace. 151 152MatcherGen::MatcherGen(const PatternToMatch &pattern, 153 const CodeGenDAGPatterns &cgp) 154: Pattern(pattern), CGP(cgp), NextRecordedOperandNo(0), 155 TheMatcher(nullptr), CurPredicate(nullptr) { 156 // We need to produce the matcher tree for the patterns source pattern. To do 157 // this we need to match the structure as well as the types. To do the type 158 // matching, we want to figure out the fewest number of type checks we need to 159 // emit. For example, if there is only one integer type supported by a 160 // target, there should be no type comparisons at all for integer patterns! 161 // 162 // To figure out the fewest number of type checks needed, clone the pattern, 163 // remove the types, then perform type inference on the pattern as a whole. 164 // If there are unresolved types, emit an explicit check for those types, 165 // apply the type to the tree, then rerun type inference. Iterate until all 166 // types are resolved. 167 // 168 PatWithNoTypes = Pattern.getSrcPattern()->clone(); 169 PatWithNoTypes->RemoveAllTypes(); 170 171 // If there are types that are manifestly known, infer them. 172 InferPossibleTypes(); 173} 174 175/// InferPossibleTypes - As we emit the pattern, we end up generating type 176/// checks and applying them to the 'PatWithNoTypes' tree. As we do this, we 177/// want to propagate implied types as far throughout the tree as possible so 178/// that we avoid doing redundant type checks. This does the type propagation. 179void MatcherGen::InferPossibleTypes() { 180 // TP - Get *SOME* tree pattern, we don't care which. It is only used for 181 // diagnostics, which we know are impossible at this point. 182 TreePattern &TP = *CGP.pf_begin()->second; 183 184 bool MadeChange = true; 185 while (MadeChange) 186 MadeChange = PatWithNoTypes->ApplyTypeConstraints(TP, 187 true/*Ignore reg constraints*/); 188} 189 190 191/// AddMatcher - Add a matcher node to the current graph we're building. 192void MatcherGen::AddMatcher(Matcher *NewNode) { 193 if (CurPredicate) 194 CurPredicate->setNext(NewNode); 195 else 196 TheMatcher = NewNode; 197 CurPredicate = NewNode; 198} 199 200 201//===----------------------------------------------------------------------===// 202// Pattern Match Generation 203//===----------------------------------------------------------------------===// 204 205/// EmitLeafMatchCode - Generate matching code for leaf nodes. 206void MatcherGen::EmitLeafMatchCode(const TreePatternNode *N) { 207 assert(N->isLeaf() && "Not a leaf?"); 208 209 // Direct match against an integer constant. 210 if (IntInit *II = dyn_cast<IntInit>(N->getLeafValue())) { 211 // If this is the root of the dag we're matching, we emit a redundant opcode 212 // check to ensure that this gets folded into the normal top-level 213 // OpcodeSwitch. 214 if (N == Pattern.getSrcPattern()) { 215 const SDNodeInfo &NI = CGP.getSDNodeInfo(CGP.getSDNodeNamed("imm")); 216 AddMatcher(new CheckOpcodeMatcher(NI)); 217 } 218 219 return AddMatcher(new CheckIntegerMatcher(II->getValue())); 220 } 221 222 // An UnsetInit represents a named node without any constraints. 223 if (N->getLeafValue() == UnsetInit::get()) { 224 assert(N->hasName() && "Unnamed ? leaf"); 225 return; 226 } 227 228 DefInit *DI = dyn_cast<DefInit>(N->getLeafValue()); 229 if (!DI) { 230 errs() << "Unknown leaf kind: " << *N << "\n"; 231 abort(); 232 } 233 234 Record *LeafRec = DI->getDef(); 235 236 // A ValueType leaf node can represent a register when named, or itself when 237 // unnamed. 238 if (LeafRec->isSubClassOf("ValueType")) { 239 // A named ValueType leaf always matches: (add i32:$a, i32:$b). 240 if (N->hasName()) 241 return; 242 // An unnamed ValueType as in (sext_inreg GPR:$foo, i8). 243 return AddMatcher(new CheckValueTypeMatcher(LeafRec->getName())); 244 } 245 246 if (// Handle register references. Nothing to do here, they always match. 247 LeafRec->isSubClassOf("RegisterClass") || 248 LeafRec->isSubClassOf("RegisterOperand") || 249 LeafRec->isSubClassOf("PointerLikeRegClass") || 250 LeafRec->isSubClassOf("SubRegIndex") || 251 // Place holder for SRCVALUE nodes. Nothing to do here. 252 LeafRec->getName() == "srcvalue") 253 return; 254 255 // If we have a physreg reference like (mul gpr:$src, EAX) then we need to 256 // record the register 257 if (LeafRec->isSubClassOf("Register")) { 258 AddMatcher(new RecordMatcher("physreg input "+LeafRec->getName(), 259 NextRecordedOperandNo)); 260 PhysRegInputs.push_back(std::make_pair(LeafRec, NextRecordedOperandNo++)); 261 return; 262 } 263 264 if (LeafRec->isSubClassOf("CondCode")) 265 return AddMatcher(new CheckCondCodeMatcher(LeafRec->getName())); 266 267 if (LeafRec->isSubClassOf("ComplexPattern")) { 268 // We can't model ComplexPattern uses that don't have their name taken yet. 269 // The OPC_CheckComplexPattern operation implicitly records the results. 270 if (N->getName().empty()) { 271 errs() << "We expect complex pattern uses to have names: " << *N << "\n"; 272 exit(1); 273 } 274 275 // Remember this ComplexPattern so that we can emit it after all the other 276 // structural matches are done. 277 unsigned InputOperand = VariableMap[N->getName()] - 1; 278 MatchedComplexPatterns.push_back(std::make_pair(N, InputOperand)); 279 return; 280 } 281 282 errs() << "Unknown leaf kind: " << *N << "\n"; 283 abort(); 284} 285 286void MatcherGen::EmitOperatorMatchCode(const TreePatternNode *N, 287 TreePatternNode *NodeNoTypes) { 288 assert(!N->isLeaf() && "Not an operator?"); 289 290 if (N->getOperator()->isSubClassOf("ComplexPattern")) { 291 // The "name" of a non-leaf complex pattern (MY_PAT $op1, $op2) is 292 // "MY_PAT:op1:op2". We should already have validated that the uses are 293 // consistent. 294 std::string PatternName = N->getOperator()->getName(); 295 for (unsigned i = 0; i < N->getNumChildren(); ++i) { 296 PatternName += ":"; 297 PatternName += N->getChild(i)->getName(); 298 } 299 300 if (recordUniqueNode(PatternName)) { 301 auto NodeAndOpNum = std::make_pair(N, NextRecordedOperandNo - 1); 302 MatchedComplexPatterns.push_back(NodeAndOpNum); 303 } 304 305 return; 306 } 307 308 const SDNodeInfo &CInfo = CGP.getSDNodeInfo(N->getOperator()); 309 310 // If this is an 'and R, 1234' where the operation is AND/OR and the RHS is 311 // a constant without a predicate fn that has more that one bit set, handle 312 // this as a special case. This is usually for targets that have special 313 // handling of certain large constants (e.g. alpha with it's 8/16/32-bit 314 // handling stuff). Using these instructions is often far more efficient 315 // than materializing the constant. Unfortunately, both the instcombiner 316 // and the dag combiner can often infer that bits are dead, and thus drop 317 // them from the mask in the dag. For example, it might turn 'AND X, 255' 318 // into 'AND X, 254' if it knows the low bit is set. Emit code that checks 319 // to handle this. 320 if ((N->getOperator()->getName() == "and" || 321 N->getOperator()->getName() == "or") && 322 N->getChild(1)->isLeaf() && N->getChild(1)->getPredicateFns().empty() && 323 N->getPredicateFns().empty()) { 324 if (IntInit *II = dyn_cast<IntInit>(N->getChild(1)->getLeafValue())) { 325 if (!isPowerOf2_32(II->getValue())) { // Don't bother with single bits. 326 // If this is at the root of the pattern, we emit a redundant 327 // CheckOpcode so that the following checks get factored properly under 328 // a single opcode check. 329 if (N == Pattern.getSrcPattern()) 330 AddMatcher(new CheckOpcodeMatcher(CInfo)); 331 332 // Emit the CheckAndImm/CheckOrImm node. 333 if (N->getOperator()->getName() == "and") 334 AddMatcher(new CheckAndImmMatcher(II->getValue())); 335 else 336 AddMatcher(new CheckOrImmMatcher(II->getValue())); 337 338 // Match the LHS of the AND as appropriate. 339 AddMatcher(new MoveChildMatcher(0)); 340 EmitMatchCode(N->getChild(0), NodeNoTypes->getChild(0)); 341 AddMatcher(new MoveParentMatcher()); 342 return; 343 } 344 } 345 } 346 347 // Check that the current opcode lines up. 348 AddMatcher(new CheckOpcodeMatcher(CInfo)); 349 350 // If this node has memory references (i.e. is a load or store), tell the 351 // interpreter to capture them in the memref array. 352 if (N->NodeHasProperty(SDNPMemOperand, CGP)) 353 AddMatcher(new RecordMemRefMatcher()); 354 355 // If this node has a chain, then the chain is operand #0 is the SDNode, and 356 // the child numbers of the node are all offset by one. 357 unsigned OpNo = 0; 358 if (N->NodeHasProperty(SDNPHasChain, CGP)) { 359 // Record the node and remember it in our chained nodes list. 360 AddMatcher(new RecordMatcher("'" + N->getOperator()->getName() + 361 "' chained node", 362 NextRecordedOperandNo)); 363 // Remember all of the input chains our pattern will match. 364 MatchedChainNodes.push_back(NextRecordedOperandNo++); 365 366 // Don't look at the input chain when matching the tree pattern to the 367 // SDNode. 368 OpNo = 1; 369 370 // If this node is not the root and the subtree underneath it produces a 371 // chain, then the result of matching the node is also produce a chain. 372 // Beyond that, this means that we're also folding (at least) the root node 373 // into the node that produce the chain (for example, matching 374 // "(add reg, (load ptr))" as a add_with_memory on X86). This is 375 // problematic, if the 'reg' node also uses the load (say, its chain). 376 // Graphically: 377 // 378 // [LD] 379 // ^ ^ 380 // | \ DAG's like cheese. 381 // / | 382 // / [YY] 383 // | ^ 384 // [XX]--/ 385 // 386 // It would be invalid to fold XX and LD. In this case, folding the two 387 // nodes together would induce a cycle in the DAG, making it a 'cyclic DAG' 388 // To prevent this, we emit a dynamic check for legality before allowing 389 // this to be folded. 390 // 391 const TreePatternNode *Root = Pattern.getSrcPattern(); 392 if (N != Root) { // Not the root of the pattern. 393 // If there is a node between the root and this node, then we definitely 394 // need to emit the check. 395 bool NeedCheck = !Root->hasChild(N); 396 397 // If it *is* an immediate child of the root, we can still need a check if 398 // the root SDNode has multiple inputs. For us, this means that it is an 399 // intrinsic, has multiple operands, or has other inputs like chain or 400 // glue). 401 if (!NeedCheck) { 402 const SDNodeInfo &PInfo = CGP.getSDNodeInfo(Root->getOperator()); 403 NeedCheck = 404 Root->getOperator() == CGP.get_intrinsic_void_sdnode() || 405 Root->getOperator() == CGP.get_intrinsic_w_chain_sdnode() || 406 Root->getOperator() == CGP.get_intrinsic_wo_chain_sdnode() || 407 PInfo.getNumOperands() > 1 || 408 PInfo.hasProperty(SDNPHasChain) || 409 PInfo.hasProperty(SDNPInGlue) || 410 PInfo.hasProperty(SDNPOptInGlue); 411 } 412 413 if (NeedCheck) 414 AddMatcher(new CheckFoldableChainNodeMatcher()); 415 } 416 } 417 418 // If this node has an output glue and isn't the root, remember it. 419 if (N->NodeHasProperty(SDNPOutGlue, CGP) && 420 N != Pattern.getSrcPattern()) { 421 // TODO: This redundantly records nodes with both glues and chains. 422 423 // Record the node and remember it in our chained nodes list. 424 AddMatcher(new RecordMatcher("'" + N->getOperator()->getName() + 425 "' glue output node", 426 NextRecordedOperandNo)); 427 // Remember all of the nodes with output glue our pattern will match. 428 MatchedGlueResultNodes.push_back(NextRecordedOperandNo++); 429 } 430 431 // If this node is known to have an input glue or if it *might* have an input 432 // glue, capture it as the glue input of the pattern. 433 if (N->NodeHasProperty(SDNPOptInGlue, CGP) || 434 N->NodeHasProperty(SDNPInGlue, CGP)) 435 AddMatcher(new CaptureGlueInputMatcher()); 436 437 for (unsigned i = 0, e = N->getNumChildren(); i != e; ++i, ++OpNo) { 438 // Get the code suitable for matching this child. Move to the child, check 439 // it then move back to the parent. 440 AddMatcher(new MoveChildMatcher(OpNo)); 441 EmitMatchCode(N->getChild(i), NodeNoTypes->getChild(i)); 442 AddMatcher(new MoveParentMatcher()); 443 } 444} 445 446bool MatcherGen::recordUniqueNode(std::string Name) { 447 unsigned &VarMapEntry = VariableMap[Name]; 448 if (VarMapEntry == 0) { 449 // If it is a named node, we must emit a 'Record' opcode. 450 AddMatcher(new RecordMatcher("$" + Name, NextRecordedOperandNo)); 451 VarMapEntry = ++NextRecordedOperandNo; 452 return true; 453 } 454 455 // If we get here, this is a second reference to a specific name. Since 456 // we already have checked that the first reference is valid, we don't 457 // have to recursively match it, just check that it's the same as the 458 // previously named thing. 459 AddMatcher(new CheckSameMatcher(VarMapEntry-1)); 460 return false; 461} 462 463void MatcherGen::EmitMatchCode(const TreePatternNode *N, 464 TreePatternNode *NodeNoTypes) { 465 // If N and NodeNoTypes don't agree on a type, then this is a case where we 466 // need to do a type check. Emit the check, apply the type to NodeNoTypes and 467 // reinfer any correlated types. 468 SmallVector<unsigned, 2> ResultsToTypeCheck; 469 470 for (unsigned i = 0, e = NodeNoTypes->getNumTypes(); i != e; ++i) { 471 if (NodeNoTypes->getExtType(i) == N->getExtType(i)) continue; 472 NodeNoTypes->setType(i, N->getExtType(i)); 473 InferPossibleTypes(); 474 ResultsToTypeCheck.push_back(i); 475 } 476 477 // If this node has a name associated with it, capture it in VariableMap. If 478 // we already saw this in the pattern, emit code to verify dagness. 479 if (!N->getName().empty()) 480 if (!recordUniqueNode(N->getName())) 481 return; 482 483 if (N->isLeaf()) 484 EmitLeafMatchCode(N); 485 else 486 EmitOperatorMatchCode(N, NodeNoTypes); 487 488 // If there are node predicates for this node, generate their checks. 489 for (unsigned i = 0, e = N->getPredicateFns().size(); i != e; ++i) 490 AddMatcher(new CheckPredicateMatcher(N->getPredicateFns()[i])); 491 492 for (unsigned i = 0, e = ResultsToTypeCheck.size(); i != e; ++i) 493 AddMatcher(new CheckTypeMatcher(N->getType(ResultsToTypeCheck[i]), 494 ResultsToTypeCheck[i])); 495} 496 497/// EmitMatcherCode - Generate the code that matches the predicate of this 498/// pattern for the specified Variant. If the variant is invalid this returns 499/// true and does not generate code, if it is valid, it returns false. 500bool MatcherGen::EmitMatcherCode(unsigned Variant) { 501 // If the root of the pattern is a ComplexPattern and if it is specified to 502 // match some number of root opcodes, these are considered to be our variants. 503 // Depending on which variant we're generating code for, emit the root opcode 504 // check. 505 if (const ComplexPattern *CP = 506 Pattern.getSrcPattern()->getComplexPatternInfo(CGP)) { 507 const std::vector<Record*> &OpNodes = CP->getRootNodes(); 508 assert(!OpNodes.empty() &&"Complex Pattern must specify what it can match"); 509 if (Variant >= OpNodes.size()) return true; 510 511 AddMatcher(new CheckOpcodeMatcher(CGP.getSDNodeInfo(OpNodes[Variant]))); 512 } else { 513 if (Variant != 0) return true; 514 } 515 516 // Emit the matcher for the pattern structure and types. 517 EmitMatchCode(Pattern.getSrcPattern(), PatWithNoTypes); 518 519 // If the pattern has a predicate on it (e.g. only enabled when a subtarget 520 // feature is around, do the check). 521 if (!Pattern.getPredicateCheck().empty()) 522 AddMatcher(new CheckPatternPredicateMatcher(Pattern.getPredicateCheck())); 523 524 // Now that we've completed the structural type match, emit any ComplexPattern 525 // checks (e.g. addrmode matches). We emit this after the structural match 526 // because they are generally more expensive to evaluate and more difficult to 527 // factor. 528 for (unsigned i = 0, e = MatchedComplexPatterns.size(); i != e; ++i) { 529 const TreePatternNode *N = MatchedComplexPatterns[i].first; 530 531 // Remember where the results of this match get stuck. 532 if (N->isLeaf()) { 533 NamedComplexPatternOperands[N->getName()] = NextRecordedOperandNo + 1; 534 } else { 535 unsigned CurOp = NextRecordedOperandNo; 536 for (unsigned i = 0; i < N->getNumChildren(); ++i) { 537 NamedComplexPatternOperands[N->getChild(i)->getName()] = CurOp + 1; 538 CurOp += N->getChild(i)->getNumMIResults(CGP); 539 } 540 } 541 542 // Get the slot we recorded the value in from the name on the node. 543 unsigned RecNodeEntry = MatchedComplexPatterns[i].second; 544 545 const ComplexPattern &CP = *N->getComplexPatternInfo(CGP); 546 547 // Emit a CheckComplexPat operation, which does the match (aborting if it 548 // fails) and pushes the matched operands onto the recorded nodes list. 549 AddMatcher(new CheckComplexPatMatcher(CP, RecNodeEntry, 550 N->getName(), NextRecordedOperandNo)); 551 552 // Record the right number of operands. 553 NextRecordedOperandNo += CP.getNumOperands(); 554 if (CP.hasProperty(SDNPHasChain)) { 555 // If the complex pattern has a chain, then we need to keep track of the 556 // fact that we just recorded a chain input. The chain input will be 557 // matched as the last operand of the predicate if it was successful. 558 ++NextRecordedOperandNo; // Chained node operand. 559 560 // It is the last operand recorded. 561 assert(NextRecordedOperandNo > 1 && 562 "Should have recorded input/result chains at least!"); 563 MatchedChainNodes.push_back(NextRecordedOperandNo-1); 564 } 565 566 // TODO: Complex patterns can't have output glues, if they did, we'd want 567 // to record them. 568 } 569 570 return false; 571} 572 573 574//===----------------------------------------------------------------------===// 575// Node Result Generation 576//===----------------------------------------------------------------------===// 577 578void MatcherGen::EmitResultOfNamedOperand(const TreePatternNode *N, 579 SmallVectorImpl<unsigned> &ResultOps){ 580 assert(!N->getName().empty() && "Operand not named!"); 581 582 if (unsigned SlotNo = NamedComplexPatternOperands[N->getName()]) { 583 // Complex operands have already been completely selected, just find the 584 // right slot ant add the arguments directly. 585 for (unsigned i = 0; i < N->getNumMIResults(CGP); ++i) 586 ResultOps.push_back(SlotNo - 1 + i); 587 588 return; 589 } 590 591 unsigned SlotNo = getNamedArgumentSlot(N->getName()); 592 593 // If this is an 'imm' or 'fpimm' node, make sure to convert it to the target 594 // version of the immediate so that it doesn't get selected due to some other 595 // node use. 596 if (!N->isLeaf()) { 597 StringRef OperatorName = N->getOperator()->getName(); 598 if (OperatorName == "imm" || OperatorName == "fpimm") { 599 AddMatcher(new EmitConvertToTargetMatcher(SlotNo)); 600 ResultOps.push_back(NextRecordedOperandNo++); 601 return; 602 } 603 } 604 605 for (unsigned i = 0; i < N->getNumMIResults(CGP); ++i) 606 ResultOps.push_back(SlotNo + i); 607} 608 609void MatcherGen::EmitResultLeafAsOperand(const TreePatternNode *N, 610 SmallVectorImpl<unsigned> &ResultOps) { 611 assert(N->isLeaf() && "Must be a leaf"); 612 613 if (IntInit *II = dyn_cast<IntInit>(N->getLeafValue())) { 614 AddMatcher(new EmitIntegerMatcher(II->getValue(), N->getType(0))); 615 ResultOps.push_back(NextRecordedOperandNo++); 616 return; 617 } 618 619 // If this is an explicit register reference, handle it. 620 if (DefInit *DI = dyn_cast<DefInit>(N->getLeafValue())) { 621 Record *Def = DI->getDef(); 622 if (Def->isSubClassOf("Register")) { 623 const CodeGenRegister *Reg = 624 CGP.getTargetInfo().getRegBank().getReg(Def); 625 AddMatcher(new EmitRegisterMatcher(Reg, N->getType(0))); 626 ResultOps.push_back(NextRecordedOperandNo++); 627 return; 628 } 629 630 if (Def->getName() == "zero_reg") { 631 AddMatcher(new EmitRegisterMatcher(nullptr, N->getType(0))); 632 ResultOps.push_back(NextRecordedOperandNo++); 633 return; 634 } 635 636 // Handle a reference to a register class. This is used 637 // in COPY_TO_SUBREG instructions. 638 if (Def->isSubClassOf("RegisterOperand")) 639 Def = Def->getValueAsDef("RegClass"); 640 if (Def->isSubClassOf("RegisterClass")) { 641 std::string Value = getQualifiedName(Def) + "RegClassID"; 642 AddMatcher(new EmitStringIntegerMatcher(Value, MVT::i32)); 643 ResultOps.push_back(NextRecordedOperandNo++); 644 return; 645 } 646 647 // Handle a subregister index. This is used for INSERT_SUBREG etc. 648 if (Def->isSubClassOf("SubRegIndex")) { 649 std::string Value = getQualifiedName(Def); 650 AddMatcher(new EmitStringIntegerMatcher(Value, MVT::i32)); 651 ResultOps.push_back(NextRecordedOperandNo++); 652 return; 653 } 654 } 655 656 errs() << "unhandled leaf node: \n"; 657 N->dump(); 658} 659 660/// GetInstPatternNode - Get the pattern for an instruction. 661/// 662const TreePatternNode *MatcherGen:: 663GetInstPatternNode(const DAGInstruction &Inst, const TreePatternNode *N) { 664 const TreePattern *InstPat = Inst.getPattern(); 665 666 // FIXME2?: Assume actual pattern comes before "implicit". 667 TreePatternNode *InstPatNode; 668 if (InstPat) 669 InstPatNode = InstPat->getTree(0); 670 else if (/*isRoot*/ N == Pattern.getDstPattern()) 671 InstPatNode = Pattern.getSrcPattern(); 672 else 673 return nullptr; 674 675 if (InstPatNode && !InstPatNode->isLeaf() && 676 InstPatNode->getOperator()->getName() == "set") 677 InstPatNode = InstPatNode->getChild(InstPatNode->getNumChildren()-1); 678 679 return InstPatNode; 680} 681 682static bool 683mayInstNodeLoadOrStore(const TreePatternNode *N, 684 const CodeGenDAGPatterns &CGP) { 685 Record *Op = N->getOperator(); 686 const CodeGenTarget &CGT = CGP.getTargetInfo(); 687 CodeGenInstruction &II = CGT.getInstruction(Op); 688 return II.mayLoad || II.mayStore; 689} 690 691static unsigned 692numNodesThatMayLoadOrStore(const TreePatternNode *N, 693 const CodeGenDAGPatterns &CGP) { 694 if (N->isLeaf()) 695 return 0; 696 697 Record *OpRec = N->getOperator(); 698 if (!OpRec->isSubClassOf("Instruction")) 699 return 0; 700 701 unsigned Count = 0; 702 if (mayInstNodeLoadOrStore(N, CGP)) 703 ++Count; 704 705 for (unsigned i = 0, e = N->getNumChildren(); i != e; ++i) 706 Count += numNodesThatMayLoadOrStore(N->getChild(i), CGP); 707 708 return Count; 709} 710 711void MatcherGen:: 712EmitResultInstructionAsOperand(const TreePatternNode *N, 713 SmallVectorImpl<unsigned> &OutputOps) { 714 Record *Op = N->getOperator(); 715 const CodeGenTarget &CGT = CGP.getTargetInfo(); 716 CodeGenInstruction &II = CGT.getInstruction(Op); 717 const DAGInstruction &Inst = CGP.getInstruction(Op); 718 719 // If we can, get the pattern for the instruction we're generating. We derive 720 // a variety of information from this pattern, such as whether it has a chain. 721 // 722 // FIXME2: This is extremely dubious for several reasons, not the least of 723 // which it gives special status to instructions with patterns that Pat<> 724 // nodes can't duplicate. 725 const TreePatternNode *InstPatNode = GetInstPatternNode(Inst, N); 726 727 // NodeHasChain - Whether the instruction node we're creating takes chains. 728 bool NodeHasChain = InstPatNode && 729 InstPatNode->TreeHasProperty(SDNPHasChain, CGP); 730 731 // Instructions which load and store from memory should have a chain, 732 // regardless of whether they happen to have an internal pattern saying so. 733 if (Pattern.getSrcPattern()->TreeHasProperty(SDNPHasChain, CGP) 734 && (II.hasCtrlDep || II.mayLoad || II.mayStore || II.canFoldAsLoad || 735 II.hasSideEffects)) 736 NodeHasChain = true; 737 738 bool isRoot = N == Pattern.getDstPattern(); 739 740 // TreeHasOutGlue - True if this tree has glue. 741 bool TreeHasInGlue = false, TreeHasOutGlue = false; 742 if (isRoot) { 743 const TreePatternNode *SrcPat = Pattern.getSrcPattern(); 744 TreeHasInGlue = SrcPat->TreeHasProperty(SDNPOptInGlue, CGP) || 745 SrcPat->TreeHasProperty(SDNPInGlue, CGP); 746 747 // FIXME2: this is checking the entire pattern, not just the node in 748 // question, doing this just for the root seems like a total hack. 749 TreeHasOutGlue = SrcPat->TreeHasProperty(SDNPOutGlue, CGP); 750 } 751 752 // NumResults - This is the number of results produced by the instruction in 753 // the "outs" list. 754 unsigned NumResults = Inst.getNumResults(); 755 756 // Number of operands we know the output instruction must have. If it is 757 // variadic, we could have more operands. 758 unsigned NumFixedOperands = II.Operands.size(); 759 760 SmallVector<unsigned, 8> InstOps; 761 762 // Loop over all of the fixed operands of the instruction pattern, emitting 763 // code to fill them all in. The node 'N' usually has number children equal to 764 // the number of input operands of the instruction. However, in cases where 765 // there are predicate operands for an instruction, we need to fill in the 766 // 'execute always' values. Match up the node operands to the instruction 767 // operands to do this. 768 unsigned ChildNo = 0; 769 for (unsigned InstOpNo = NumResults, e = NumFixedOperands; 770 InstOpNo != e; ++InstOpNo) { 771 // Determine what to emit for this operand. 772 Record *OperandNode = II.Operands[InstOpNo].Rec; 773 if (OperandNode->isSubClassOf("OperandWithDefaultOps") && 774 !CGP.getDefaultOperand(OperandNode).DefaultOps.empty()) { 775 // This is a predicate or optional def operand; emit the 776 // 'default ops' operands. 777 const DAGDefaultOperand &DefaultOp 778 = CGP.getDefaultOperand(OperandNode); 779 for (unsigned i = 0, e = DefaultOp.DefaultOps.size(); i != e; ++i) 780 EmitResultOperand(DefaultOp.DefaultOps[i], InstOps); 781 continue; 782 } 783 784 // Otherwise this is a normal operand or a predicate operand without 785 // 'execute always'; emit it. 786 787 // For operands with multiple sub-operands we may need to emit 788 // multiple child patterns to cover them all. However, ComplexPattern 789 // children may themselves emit multiple MI operands. 790 unsigned NumSubOps = 1; 791 if (OperandNode->isSubClassOf("Operand")) { 792 DagInit *MIOpInfo = OperandNode->getValueAsDag("MIOperandInfo"); 793 if (unsigned NumArgs = MIOpInfo->getNumArgs()) 794 NumSubOps = NumArgs; 795 } 796 797 unsigned FinalNumOps = InstOps.size() + NumSubOps; 798 while (InstOps.size() < FinalNumOps) { 799 const TreePatternNode *Child = N->getChild(ChildNo); 800 unsigned BeforeAddingNumOps = InstOps.size(); 801 EmitResultOperand(Child, InstOps); 802 assert(InstOps.size() > BeforeAddingNumOps && "Didn't add any operands"); 803 804 // If the operand is an instruction and it produced multiple results, just 805 // take the first one. 806 if (!Child->isLeaf() && Child->getOperator()->isSubClassOf("Instruction")) 807 InstOps.resize(BeforeAddingNumOps+1); 808 809 ++ChildNo; 810 } 811 } 812 813 // If this is a variadic output instruction (i.e. REG_SEQUENCE), we can't 814 // expand suboperands, use default operands, or other features determined from 815 // the CodeGenInstruction after the fixed operands, which were handled 816 // above. Emit the remaining instructions implicitly added by the use for 817 // variable_ops. 818 if (II.Operands.isVariadic) { 819 for (unsigned I = ChildNo, E = N->getNumChildren(); I < E; ++I) 820 EmitResultOperand(N->getChild(I), InstOps); 821 } 822 823 // If this node has input glue or explicitly specified input physregs, we 824 // need to add chained and glued copyfromreg nodes and materialize the glue 825 // input. 826 if (isRoot && !PhysRegInputs.empty()) { 827 // Emit all of the CopyToReg nodes for the input physical registers. These 828 // occur in patterns like (mul:i8 AL:i8, GR8:i8:$src). 829 for (unsigned i = 0, e = PhysRegInputs.size(); i != e; ++i) 830 AddMatcher(new EmitCopyToRegMatcher(PhysRegInputs[i].second, 831 PhysRegInputs[i].first)); 832 // Even if the node has no other glue inputs, the resultant node must be 833 // glued to the CopyFromReg nodes we just generated. 834 TreeHasInGlue = true; 835 } 836 837 // Result order: node results, chain, glue 838 839 // Determine the result types. 840 SmallVector<MVT::SimpleValueType, 4> ResultVTs; 841 for (unsigned i = 0, e = N->getNumTypes(); i != e; ++i) 842 ResultVTs.push_back(N->getType(i)); 843 844 // If this is the root instruction of a pattern that has physical registers in 845 // its result pattern, add output VTs for them. For example, X86 has: 846 // (set AL, (mul ...)) 847 // This also handles implicit results like: 848 // (implicit EFLAGS) 849 if (isRoot && !Pattern.getDstRegs().empty()) { 850 // If the root came from an implicit def in the instruction handling stuff, 851 // don't re-add it. 852 Record *HandledReg = nullptr; 853 if (II.HasOneImplicitDefWithKnownVT(CGT) != MVT::Other) 854 HandledReg = II.ImplicitDefs[0]; 855 856 for (unsigned i = 0; i != Pattern.getDstRegs().size(); ++i) { 857 Record *Reg = Pattern.getDstRegs()[i]; 858 if (!Reg->isSubClassOf("Register") || Reg == HandledReg) continue; 859 ResultVTs.push_back(getRegisterValueType(Reg, CGT)); 860 } 861 } 862 863 // If this is the root of the pattern and the pattern we're matching includes 864 // a node that is variadic, mark the generated node as variadic so that it 865 // gets the excess operands from the input DAG. 866 int NumFixedArityOperands = -1; 867 if (isRoot && 868 Pattern.getSrcPattern()->NodeHasProperty(SDNPVariadic, CGP)) 869 NumFixedArityOperands = Pattern.getSrcPattern()->getNumChildren(); 870 871 // If this is the root node and multiple matched nodes in the input pattern 872 // have MemRefs in them, have the interpreter collect them and plop them onto 873 // this node. If there is just one node with MemRefs, leave them on that node 874 // even if it is not the root. 875 // 876 // FIXME3: This is actively incorrect for result patterns with multiple 877 // memory-referencing instructions. 878 bool PatternHasMemOperands = 879 Pattern.getSrcPattern()->TreeHasProperty(SDNPMemOperand, CGP); 880 881 bool NodeHasMemRefs = false; 882 if (PatternHasMemOperands) { 883 unsigned NumNodesThatLoadOrStore = 884 numNodesThatMayLoadOrStore(Pattern.getDstPattern(), CGP); 885 bool NodeIsUniqueLoadOrStore = mayInstNodeLoadOrStore(N, CGP) && 886 NumNodesThatLoadOrStore == 1; 887 NodeHasMemRefs = 888 NodeIsUniqueLoadOrStore || (isRoot && (mayInstNodeLoadOrStore(N, CGP) || 889 NumNodesThatLoadOrStore != 1)); 890 } 891 892 assert((!ResultVTs.empty() || TreeHasOutGlue || NodeHasChain) && 893 "Node has no result"); 894 895 AddMatcher(new EmitNodeMatcher(II.Namespace+"::"+II.TheDef->getName(), 896 ResultVTs, InstOps, 897 NodeHasChain, TreeHasInGlue, TreeHasOutGlue, 898 NodeHasMemRefs, NumFixedArityOperands, 899 NextRecordedOperandNo)); 900 901 // The non-chain and non-glue results of the newly emitted node get recorded. 902 for (unsigned i = 0, e = ResultVTs.size(); i != e; ++i) { 903 if (ResultVTs[i] == MVT::Other || ResultVTs[i] == MVT::Glue) break; 904 OutputOps.push_back(NextRecordedOperandNo++); 905 } 906} 907 908void MatcherGen:: 909EmitResultSDNodeXFormAsOperand(const TreePatternNode *N, 910 SmallVectorImpl<unsigned> &ResultOps) { 911 assert(N->getOperator()->isSubClassOf("SDNodeXForm") && "Not SDNodeXForm?"); 912 913 // Emit the operand. 914 SmallVector<unsigned, 8> InputOps; 915 916 // FIXME2: Could easily generalize this to support multiple inputs and outputs 917 // to the SDNodeXForm. For now we just support one input and one output like 918 // the old instruction selector. 919 assert(N->getNumChildren() == 1); 920 EmitResultOperand(N->getChild(0), InputOps); 921 922 // The input currently must have produced exactly one result. 923 assert(InputOps.size() == 1 && "Unexpected input to SDNodeXForm"); 924 925 AddMatcher(new EmitNodeXFormMatcher(InputOps[0], N->getOperator())); 926 ResultOps.push_back(NextRecordedOperandNo++); 927} 928 929void MatcherGen::EmitResultOperand(const TreePatternNode *N, 930 SmallVectorImpl<unsigned> &ResultOps) { 931 // This is something selected from the pattern we matched. 932 if (!N->getName().empty()) 933 return EmitResultOfNamedOperand(N, ResultOps); 934 935 if (N->isLeaf()) 936 return EmitResultLeafAsOperand(N, ResultOps); 937 938 Record *OpRec = N->getOperator(); 939 if (OpRec->isSubClassOf("Instruction")) 940 return EmitResultInstructionAsOperand(N, ResultOps); 941 if (OpRec->isSubClassOf("SDNodeXForm")) 942 return EmitResultSDNodeXFormAsOperand(N, ResultOps); 943 errs() << "Unknown result node to emit code for: " << *N << '\n'; 944 PrintFatalError("Unknown node in result pattern!"); 945} 946 947void MatcherGen::EmitResultCode() { 948 // Patterns that match nodes with (potentially multiple) chain inputs have to 949 // merge them together into a token factor. This informs the generated code 950 // what all the chained nodes are. 951 if (!MatchedChainNodes.empty()) 952 AddMatcher(new EmitMergeInputChainsMatcher(MatchedChainNodes)); 953 954 // Codegen the root of the result pattern, capturing the resulting values. 955 SmallVector<unsigned, 8> Ops; 956 EmitResultOperand(Pattern.getDstPattern(), Ops); 957 958 // At this point, we have however many values the result pattern produces. 959 // However, the input pattern might not need all of these. If there are 960 // excess values at the end (such as implicit defs of condition codes etc) 961 // just lop them off. This doesn't need to worry about glue or chains, just 962 // explicit results. 963 // 964 unsigned NumSrcResults = Pattern.getSrcPattern()->getNumTypes(); 965 966 // If the pattern also has (implicit) results, count them as well. 967 if (!Pattern.getDstRegs().empty()) { 968 // If the root came from an implicit def in the instruction handling stuff, 969 // don't re-add it. 970 Record *HandledReg = nullptr; 971 const TreePatternNode *DstPat = Pattern.getDstPattern(); 972 if (!DstPat->isLeaf() &&DstPat->getOperator()->isSubClassOf("Instruction")){ 973 const CodeGenTarget &CGT = CGP.getTargetInfo(); 974 CodeGenInstruction &II = CGT.getInstruction(DstPat->getOperator()); 975 976 if (II.HasOneImplicitDefWithKnownVT(CGT) != MVT::Other) 977 HandledReg = II.ImplicitDefs[0]; 978 } 979 980 for (unsigned i = 0; i != Pattern.getDstRegs().size(); ++i) { 981 Record *Reg = Pattern.getDstRegs()[i]; 982 if (!Reg->isSubClassOf("Register") || Reg == HandledReg) continue; 983 ++NumSrcResults; 984 } 985 } 986 987 assert(Ops.size() >= NumSrcResults && "Didn't provide enough results"); 988 Ops.resize(NumSrcResults); 989 990 // If the matched pattern covers nodes which define a glue result, emit a node 991 // that tells the matcher about them so that it can update their results. 992 if (!MatchedGlueResultNodes.empty()) 993 AddMatcher(new MarkGlueResultsMatcher(MatchedGlueResultNodes)); 994 995 AddMatcher(new CompleteMatchMatcher(Ops, Pattern)); 996} 997 998 999/// ConvertPatternToMatcher - Create the matcher for the specified pattern with 1000/// the specified variant. If the variant number is invalid, this returns null. 1001Matcher *llvm::ConvertPatternToMatcher(const PatternToMatch &Pattern, 1002 unsigned Variant, 1003 const CodeGenDAGPatterns &CGP) { 1004 MatcherGen Gen(Pattern, CGP); 1005 1006 // Generate the code for the matcher. 1007 if (Gen.EmitMatcherCode(Variant)) 1008 return nullptr; 1009 1010 // FIXME2: Kill extra MoveParent commands at the end of the matcher sequence. 1011 // FIXME2: Split result code out to another table, and make the matcher end 1012 // with an "Emit <index>" command. This allows result generation stuff to be 1013 // shared and factored? 1014 1015 // If the match succeeds, then we generate Pattern. 1016 Gen.EmitResultCode(); 1017 1018 // Unconditional match. 1019 return Gen.GetMatcher(); 1020} 1021