1 //===-- LegalizeTypes.cpp - Common code for DAG type legalizer ------------===// 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 SelectionDAG::LegalizeTypes method. It transforms 11 // an arbitrary well-formed SelectionDAG to only consist of legal types. This 12 // is common code shared among the LegalizeTypes*.cpp files. 13 // 14 //===----------------------------------------------------------------------===// 15 16 #include "LegalizeTypes.h" 17 #include "llvm/ADT/SetVector.h" 18 #include "llvm/IR/CallingConv.h" 19 #include "llvm/IR/DataLayout.h" 20 #include "llvm/Support/CommandLine.h" 21 #include "llvm/Support/ErrorHandling.h" 22 #include "llvm/Support/raw_ostream.h" 23 using namespace llvm; 24 25 #define DEBUG_TYPE "legalize-types" 26 27 static cl::opt<bool> 28 EnableExpensiveChecks("enable-legalize-types-checking", cl::Hidden); 29 30 /// PerformExpensiveChecks - Do extensive, expensive, sanity checking. 31 void DAGTypeLegalizer::PerformExpensiveChecks() { 32 // If a node is not processed, then none of its values should be mapped by any 33 // of PromotedIntegers, ExpandedIntegers, ..., ReplacedValues. 34 35 // If a node is processed, then each value with an illegal type must be mapped 36 // by exactly one of PromotedIntegers, ExpandedIntegers, ..., ReplacedValues. 37 // Values with a legal type may be mapped by ReplacedValues, but not by any of 38 // the other maps. 39 40 // Note that these invariants may not hold momentarily when processing a node: 41 // the node being processed may be put in a map before being marked Processed. 42 43 // Note that it is possible to have nodes marked NewNode in the DAG. This can 44 // occur in two ways. Firstly, a node may be created during legalization but 45 // never passed to the legalization core. This is usually due to the implicit 46 // folding that occurs when using the DAG.getNode operators. Secondly, a new 47 // node may be passed to the legalization core, but when analyzed may morph 48 // into a different node, leaving the original node as a NewNode in the DAG. 49 // A node may morph if one of its operands changes during analysis. Whether 50 // it actually morphs or not depends on whether, after updating its operands, 51 // it is equivalent to an existing node: if so, it morphs into that existing 52 // node (CSE). An operand can change during analysis if the operand is a new 53 // node that morphs, or it is a processed value that was mapped to some other 54 // value (as recorded in ReplacedValues) in which case the operand is turned 55 // into that other value. If a node morphs then the node it morphed into will 56 // be used instead of it for legalization, however the original node continues 57 // to live on in the DAG. 58 // The conclusion is that though there may be nodes marked NewNode in the DAG, 59 // all uses of such nodes are also marked NewNode: the result is a fungus of 60 // NewNodes growing on top of the useful nodes, and perhaps using them, but 61 // not used by them. 62 63 // If a value is mapped by ReplacedValues, then it must have no uses, except 64 // by nodes marked NewNode (see above). 65 66 // The final node obtained by mapping by ReplacedValues is not marked NewNode. 67 // Note that ReplacedValues should be applied iteratively. 68 69 // Note that the ReplacedValues map may also map deleted nodes (by iterating 70 // over the DAG we never dereference deleted nodes). This means that it may 71 // also map nodes marked NewNode if the deallocated memory was reallocated as 72 // another node, and that new node was not seen by the LegalizeTypes machinery 73 // (for example because it was created but not used). In general, we cannot 74 // distinguish between new nodes and deleted nodes. 75 SmallVector<SDNode*, 16> NewNodes; 76 for (SelectionDAG::allnodes_iterator I = DAG.allnodes_begin(), 77 E = DAG.allnodes_end(); I != E; ++I) { 78 // Remember nodes marked NewNode - they are subject to extra checking below. 79 if (I->getNodeId() == NewNode) 80 NewNodes.push_back(I); 81 82 for (unsigned i = 0, e = I->getNumValues(); i != e; ++i) { 83 SDValue Res(I, i); 84 bool Failed = false; 85 86 unsigned Mapped = 0; 87 if (ReplacedValues.find(Res) != ReplacedValues.end()) { 88 Mapped |= 1; 89 // Check that remapped values are only used by nodes marked NewNode. 90 for (SDNode::use_iterator UI = I->use_begin(), UE = I->use_end(); 91 UI != UE; ++UI) 92 if (UI.getUse().getResNo() == i) 93 assert(UI->getNodeId() == NewNode && 94 "Remapped value has non-trivial use!"); 95 96 // Check that the final result of applying ReplacedValues is not 97 // marked NewNode. 98 SDValue NewVal = ReplacedValues[Res]; 99 DenseMap<SDValue, SDValue>::iterator I = ReplacedValues.find(NewVal); 100 while (I != ReplacedValues.end()) { 101 NewVal = I->second; 102 I = ReplacedValues.find(NewVal); 103 } 104 assert(NewVal.getNode()->getNodeId() != NewNode && 105 "ReplacedValues maps to a new node!"); 106 } 107 if (PromotedIntegers.find(Res) != PromotedIntegers.end()) 108 Mapped |= 2; 109 if (SoftenedFloats.find(Res) != SoftenedFloats.end()) 110 Mapped |= 4; 111 if (ScalarizedVectors.find(Res) != ScalarizedVectors.end()) 112 Mapped |= 8; 113 if (ExpandedIntegers.find(Res) != ExpandedIntegers.end()) 114 Mapped |= 16; 115 if (ExpandedFloats.find(Res) != ExpandedFloats.end()) 116 Mapped |= 32; 117 if (SplitVectors.find(Res) != SplitVectors.end()) 118 Mapped |= 64; 119 if (WidenedVectors.find(Res) != WidenedVectors.end()) 120 Mapped |= 128; 121 122 if (I->getNodeId() != Processed) { 123 // Since we allow ReplacedValues to map deleted nodes, it may map nodes 124 // marked NewNode too, since a deleted node may have been reallocated as 125 // another node that has not been seen by the LegalizeTypes machinery. 126 if ((I->getNodeId() == NewNode && Mapped > 1) || 127 (I->getNodeId() != NewNode && Mapped != 0)) { 128 dbgs() << "Unprocessed value in a map!"; 129 Failed = true; 130 } 131 } else if (isTypeLegal(Res.getValueType()) || IgnoreNodeResults(I)) { 132 if (Mapped > 1) { 133 dbgs() << "Value with legal type was transformed!"; 134 Failed = true; 135 } 136 } else { 137 if (Mapped == 0) { 138 dbgs() << "Processed value not in any map!"; 139 Failed = true; 140 } else if (Mapped & (Mapped - 1)) { 141 dbgs() << "Value in multiple maps!"; 142 Failed = true; 143 } 144 } 145 146 if (Failed) { 147 if (Mapped & 1) 148 dbgs() << " ReplacedValues"; 149 if (Mapped & 2) 150 dbgs() << " PromotedIntegers"; 151 if (Mapped & 4) 152 dbgs() << " SoftenedFloats"; 153 if (Mapped & 8) 154 dbgs() << " ScalarizedVectors"; 155 if (Mapped & 16) 156 dbgs() << " ExpandedIntegers"; 157 if (Mapped & 32) 158 dbgs() << " ExpandedFloats"; 159 if (Mapped & 64) 160 dbgs() << " SplitVectors"; 161 if (Mapped & 128) 162 dbgs() << " WidenedVectors"; 163 dbgs() << "\n"; 164 llvm_unreachable(nullptr); 165 } 166 } 167 } 168 169 // Checked that NewNodes are only used by other NewNodes. 170 for (unsigned i = 0, e = NewNodes.size(); i != e; ++i) { 171 SDNode *N = NewNodes[i]; 172 for (SDNode::use_iterator UI = N->use_begin(), UE = N->use_end(); 173 UI != UE; ++UI) 174 assert(UI->getNodeId() == NewNode && "NewNode used by non-NewNode!"); 175 } 176 } 177 178 /// run - This is the main entry point for the type legalizer. This does a 179 /// top-down traversal of the dag, legalizing types as it goes. Returns "true" 180 /// if it made any changes. 181 bool DAGTypeLegalizer::run() { 182 bool Changed = false; 183 184 // Create a dummy node (which is not added to allnodes), that adds a reference 185 // to the root node, preventing it from being deleted, and tracking any 186 // changes of the root. 187 HandleSDNode Dummy(DAG.getRoot()); 188 Dummy.setNodeId(Unanalyzed); 189 190 // The root of the dag may dangle to deleted nodes until the type legalizer is 191 // done. Set it to null to avoid confusion. 192 DAG.setRoot(SDValue()); 193 194 // Walk all nodes in the graph, assigning them a NodeId of 'ReadyToProcess' 195 // (and remembering them) if they are leaves and assigning 'Unanalyzed' if 196 // non-leaves. 197 for (SelectionDAG::allnodes_iterator I = DAG.allnodes_begin(), 198 E = DAG.allnodes_end(); I != E; ++I) { 199 if (I->getNumOperands() == 0) { 200 I->setNodeId(ReadyToProcess); 201 Worklist.push_back(I); 202 } else { 203 I->setNodeId(Unanalyzed); 204 } 205 } 206 207 // Now that we have a set of nodes to process, handle them all. 208 while (!Worklist.empty()) { 209 #ifndef XDEBUG 210 if (EnableExpensiveChecks) 211 #endif 212 PerformExpensiveChecks(); 213 214 SDNode *N = Worklist.back(); 215 Worklist.pop_back(); 216 assert(N->getNodeId() == ReadyToProcess && 217 "Node should be ready if on worklist!"); 218 219 if (IgnoreNodeResults(N)) 220 goto ScanOperands; 221 222 // Scan the values produced by the node, checking to see if any result 223 // types are illegal. 224 for (unsigned i = 0, NumResults = N->getNumValues(); i < NumResults; ++i) { 225 EVT ResultVT = N->getValueType(i); 226 switch (getTypeAction(ResultVT)) { 227 case TargetLowering::TypeLegal: 228 break; 229 // The following calls must take care of *all* of the node's results, 230 // not just the illegal result they were passed (this includes results 231 // with a legal type). Results can be remapped using ReplaceValueWith, 232 // or their promoted/expanded/etc values registered in PromotedIntegers, 233 // ExpandedIntegers etc. 234 case TargetLowering::TypePromoteInteger: 235 PromoteIntegerResult(N, i); 236 Changed = true; 237 goto NodeDone; 238 case TargetLowering::TypeExpandInteger: 239 ExpandIntegerResult(N, i); 240 Changed = true; 241 goto NodeDone; 242 case TargetLowering::TypeSoftenFloat: 243 SoftenFloatResult(N, i); 244 Changed = true; 245 goto NodeDone; 246 case TargetLowering::TypeExpandFloat: 247 ExpandFloatResult(N, i); 248 Changed = true; 249 goto NodeDone; 250 case TargetLowering::TypeScalarizeVector: 251 ScalarizeVectorResult(N, i); 252 Changed = true; 253 goto NodeDone; 254 case TargetLowering::TypeSplitVector: 255 SplitVectorResult(N, i); 256 Changed = true; 257 goto NodeDone; 258 case TargetLowering::TypeWidenVector: 259 WidenVectorResult(N, i); 260 Changed = true; 261 goto NodeDone; 262 } 263 } 264 265 ScanOperands: 266 // Scan the operand list for the node, handling any nodes with operands that 267 // are illegal. 268 { 269 unsigned NumOperands = N->getNumOperands(); 270 bool NeedsReanalyzing = false; 271 unsigned i; 272 for (i = 0; i != NumOperands; ++i) { 273 if (IgnoreNodeResults(N->getOperand(i).getNode())) 274 continue; 275 276 EVT OpVT = N->getOperand(i).getValueType(); 277 switch (getTypeAction(OpVT)) { 278 case TargetLowering::TypeLegal: 279 continue; 280 // The following calls must either replace all of the node's results 281 // using ReplaceValueWith, and return "false"; or update the node's 282 // operands in place, and return "true". 283 case TargetLowering::TypePromoteInteger: 284 NeedsReanalyzing = PromoteIntegerOperand(N, i); 285 Changed = true; 286 break; 287 case TargetLowering::TypeExpandInteger: 288 NeedsReanalyzing = ExpandIntegerOperand(N, i); 289 Changed = true; 290 break; 291 case TargetLowering::TypeSoftenFloat: 292 NeedsReanalyzing = SoftenFloatOperand(N, i); 293 Changed = true; 294 break; 295 case TargetLowering::TypeExpandFloat: 296 NeedsReanalyzing = ExpandFloatOperand(N, i); 297 Changed = true; 298 break; 299 case TargetLowering::TypeScalarizeVector: 300 NeedsReanalyzing = ScalarizeVectorOperand(N, i); 301 Changed = true; 302 break; 303 case TargetLowering::TypeSplitVector: 304 NeedsReanalyzing = SplitVectorOperand(N, i); 305 Changed = true; 306 break; 307 case TargetLowering::TypeWidenVector: 308 NeedsReanalyzing = WidenVectorOperand(N, i); 309 Changed = true; 310 break; 311 } 312 break; 313 } 314 315 // The sub-method updated N in place. Check to see if any operands are new, 316 // and if so, mark them. If the node needs revisiting, don't add all users 317 // to the worklist etc. 318 if (NeedsReanalyzing) { 319 assert(N->getNodeId() == ReadyToProcess && "Node ID recalculated?"); 320 N->setNodeId(NewNode); 321 // Recompute the NodeId and correct processed operands, adding the node to 322 // the worklist if ready. 323 SDNode *M = AnalyzeNewNode(N); 324 if (M == N) 325 // The node didn't morph - nothing special to do, it will be revisited. 326 continue; 327 328 // The node morphed - this is equivalent to legalizing by replacing every 329 // value of N with the corresponding value of M. So do that now. 330 assert(N->getNumValues() == M->getNumValues() && 331 "Node morphing changed the number of results!"); 332 for (unsigned i = 0, e = N->getNumValues(); i != e; ++i) 333 // Replacing the value takes care of remapping the new value. 334 ReplaceValueWith(SDValue(N, i), SDValue(M, i)); 335 assert(N->getNodeId() == NewNode && "Unexpected node state!"); 336 // The node continues to live on as part of the NewNode fungus that 337 // grows on top of the useful nodes. Nothing more needs to be done 338 // with it - move on to the next node. 339 continue; 340 } 341 342 if (i == NumOperands) { 343 DEBUG(dbgs() << "Legally typed node: "; N->dump(&DAG); dbgs() << "\n"); 344 } 345 } 346 NodeDone: 347 348 // If we reach here, the node was processed, potentially creating new nodes. 349 // Mark it as processed and add its users to the worklist as appropriate. 350 assert(N->getNodeId() == ReadyToProcess && "Node ID recalculated?"); 351 N->setNodeId(Processed); 352 353 for (SDNode::use_iterator UI = N->use_begin(), E = N->use_end(); 354 UI != E; ++UI) { 355 SDNode *User = *UI; 356 int NodeId = User->getNodeId(); 357 358 // This node has two options: it can either be a new node or its Node ID 359 // may be a count of the number of operands it has that are not ready. 360 if (NodeId > 0) { 361 User->setNodeId(NodeId-1); 362 363 // If this was the last use it was waiting on, add it to the ready list. 364 if (NodeId-1 == ReadyToProcess) 365 Worklist.push_back(User); 366 continue; 367 } 368 369 // If this is an unreachable new node, then ignore it. If it ever becomes 370 // reachable by being used by a newly created node then it will be handled 371 // by AnalyzeNewNode. 372 if (NodeId == NewNode) 373 continue; 374 375 // Otherwise, this node is new: this is the first operand of it that 376 // became ready. Its new NodeId is the number of operands it has minus 1 377 // (as this node is now processed). 378 assert(NodeId == Unanalyzed && "Unknown node ID!"); 379 User->setNodeId(User->getNumOperands() - 1); 380 381 // If the node only has a single operand, it is now ready. 382 if (User->getNumOperands() == 1) 383 Worklist.push_back(User); 384 } 385 } 386 387 #ifndef XDEBUG 388 if (EnableExpensiveChecks) 389 #endif 390 PerformExpensiveChecks(); 391 392 // If the root changed (e.g. it was a dead load) update the root. 393 DAG.setRoot(Dummy.getValue()); 394 395 // Remove dead nodes. This is important to do for cleanliness but also before 396 // the checking loop below. Implicit folding by the DAG.getNode operators and 397 // node morphing can cause unreachable nodes to be around with their flags set 398 // to new. 399 DAG.RemoveDeadNodes(); 400 401 // In a debug build, scan all the nodes to make sure we found them all. This 402 // ensures that there are no cycles and that everything got processed. 403 #ifndef NDEBUG 404 for (SelectionDAG::allnodes_iterator I = DAG.allnodes_begin(), 405 E = DAG.allnodes_end(); I != E; ++I) { 406 bool Failed = false; 407 408 // Check that all result types are legal. 409 if (!IgnoreNodeResults(I)) 410 for (unsigned i = 0, NumVals = I->getNumValues(); i < NumVals; ++i) 411 if (!isTypeLegal(I->getValueType(i))) { 412 dbgs() << "Result type " << i << " illegal!\n"; 413 Failed = true; 414 } 415 416 // Check that all operand types are legal. 417 for (unsigned i = 0, NumOps = I->getNumOperands(); i < NumOps; ++i) 418 if (!IgnoreNodeResults(I->getOperand(i).getNode()) && 419 !isTypeLegal(I->getOperand(i).getValueType())) { 420 dbgs() << "Operand type " << i << " illegal!\n"; 421 Failed = true; 422 } 423 424 if (I->getNodeId() != Processed) { 425 if (I->getNodeId() == NewNode) 426 dbgs() << "New node not analyzed?\n"; 427 else if (I->getNodeId() == Unanalyzed) 428 dbgs() << "Unanalyzed node not noticed?\n"; 429 else if (I->getNodeId() > 0) 430 dbgs() << "Operand not processed?\n"; 431 else if (I->getNodeId() == ReadyToProcess) 432 dbgs() << "Not added to worklist?\n"; 433 Failed = true; 434 } 435 436 if (Failed) { 437 I->dump(&DAG); dbgs() << "\n"; 438 llvm_unreachable(nullptr); 439 } 440 } 441 #endif 442 443 return Changed; 444 } 445 446 /// AnalyzeNewNode - The specified node is the root of a subtree of potentially 447 /// new nodes. Correct any processed operands (this may change the node) and 448 /// calculate the NodeId. If the node itself changes to a processed node, it 449 /// is not remapped - the caller needs to take care of this. 450 /// Returns the potentially changed node. 451 SDNode *DAGTypeLegalizer::AnalyzeNewNode(SDNode *N) { 452 // If this was an existing node that is already done, we're done. 453 if (N->getNodeId() != NewNode && N->getNodeId() != Unanalyzed) 454 return N; 455 456 // Remove any stale map entries. 457 ExpungeNode(N); 458 459 // Okay, we know that this node is new. Recursively walk all of its operands 460 // to see if they are new also. The depth of this walk is bounded by the size 461 // of the new tree that was constructed (usually 2-3 nodes), so we don't worry 462 // about revisiting of nodes. 463 // 464 // As we walk the operands, keep track of the number of nodes that are 465 // processed. If non-zero, this will become the new nodeid of this node. 466 // Operands may morph when they are analyzed. If so, the node will be 467 // updated after all operands have been analyzed. Since this is rare, 468 // the code tries to minimize overhead in the non-morphing case. 469 470 SmallVector<SDValue, 8> NewOps; 471 unsigned NumProcessed = 0; 472 for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i) { 473 SDValue OrigOp = N->getOperand(i); 474 SDValue Op = OrigOp; 475 476 AnalyzeNewValue(Op); // Op may morph. 477 478 if (Op.getNode()->getNodeId() == Processed) 479 ++NumProcessed; 480 481 if (!NewOps.empty()) { 482 // Some previous operand changed. Add this one to the list. 483 NewOps.push_back(Op); 484 } else if (Op != OrigOp) { 485 // This is the first operand to change - add all operands so far. 486 NewOps.append(N->op_begin(), N->op_begin() + i); 487 NewOps.push_back(Op); 488 } 489 } 490 491 // Some operands changed - update the node. 492 if (!NewOps.empty()) { 493 SDNode *M = DAG.UpdateNodeOperands(N, NewOps); 494 if (M != N) { 495 // The node morphed into a different node. Normally for this to happen 496 // the original node would have to be marked NewNode. However this can 497 // in theory momentarily not be the case while ReplaceValueWith is doing 498 // its stuff. Mark the original node NewNode to help sanity checking. 499 N->setNodeId(NewNode); 500 if (M->getNodeId() != NewNode && M->getNodeId() != Unanalyzed) 501 // It morphed into a previously analyzed node - nothing more to do. 502 return M; 503 504 // It morphed into a different new node. Do the equivalent of passing 505 // it to AnalyzeNewNode: expunge it and calculate the NodeId. No need 506 // to remap the operands, since they are the same as the operands we 507 // remapped above. 508 N = M; 509 ExpungeNode(N); 510 } 511 } 512 513 // Calculate the NodeId. 514 N->setNodeId(N->getNumOperands() - NumProcessed); 515 if (N->getNodeId() == ReadyToProcess) 516 Worklist.push_back(N); 517 518 return N; 519 } 520 521 /// AnalyzeNewValue - Call AnalyzeNewNode, updating the node in Val if needed. 522 /// If the node changes to a processed node, then remap it. 523 void DAGTypeLegalizer::AnalyzeNewValue(SDValue &Val) { 524 Val.setNode(AnalyzeNewNode(Val.getNode())); 525 if (Val.getNode()->getNodeId() == Processed) 526 // We were passed a processed node, or it morphed into one - remap it. 527 RemapValue(Val); 528 } 529 530 /// ExpungeNode - If N has a bogus mapping in ReplacedValues, eliminate it. 531 /// This can occur when a node is deleted then reallocated as a new node - 532 /// the mapping in ReplacedValues applies to the deleted node, not the new 533 /// one. 534 /// The only map that can have a deleted node as a source is ReplacedValues. 535 /// Other maps can have deleted nodes as targets, but since their looked-up 536 /// values are always immediately remapped using RemapValue, resulting in a 537 /// not-deleted node, this is harmless as long as ReplacedValues/RemapValue 538 /// always performs correct mappings. In order to keep the mapping correct, 539 /// ExpungeNode should be called on any new nodes *before* adding them as 540 /// either source or target to ReplacedValues (which typically means calling 541 /// Expunge when a new node is first seen, since it may no longer be marked 542 /// NewNode by the time it is added to ReplacedValues). 543 void DAGTypeLegalizer::ExpungeNode(SDNode *N) { 544 if (N->getNodeId() != NewNode) 545 return; 546 547 // If N is not remapped by ReplacedValues then there is nothing to do. 548 unsigned i, e; 549 for (i = 0, e = N->getNumValues(); i != e; ++i) 550 if (ReplacedValues.find(SDValue(N, i)) != ReplacedValues.end()) 551 break; 552 553 if (i == e) 554 return; 555 556 // Remove N from all maps - this is expensive but rare. 557 558 for (DenseMap<SDValue, SDValue>::iterator I = PromotedIntegers.begin(), 559 E = PromotedIntegers.end(); I != E; ++I) { 560 assert(I->first.getNode() != N); 561 RemapValue(I->second); 562 } 563 564 for (DenseMap<SDValue, SDValue>::iterator I = SoftenedFloats.begin(), 565 E = SoftenedFloats.end(); I != E; ++I) { 566 assert(I->first.getNode() != N); 567 RemapValue(I->second); 568 } 569 570 for (DenseMap<SDValue, SDValue>::iterator I = ScalarizedVectors.begin(), 571 E = ScalarizedVectors.end(); I != E; ++I) { 572 assert(I->first.getNode() != N); 573 RemapValue(I->second); 574 } 575 576 for (DenseMap<SDValue, SDValue>::iterator I = WidenedVectors.begin(), 577 E = WidenedVectors.end(); I != E; ++I) { 578 assert(I->first.getNode() != N); 579 RemapValue(I->second); 580 } 581 582 for (DenseMap<SDValue, std::pair<SDValue, SDValue> >::iterator 583 I = ExpandedIntegers.begin(), E = ExpandedIntegers.end(); I != E; ++I){ 584 assert(I->first.getNode() != N); 585 RemapValue(I->second.first); 586 RemapValue(I->second.second); 587 } 588 589 for (DenseMap<SDValue, std::pair<SDValue, SDValue> >::iterator 590 I = ExpandedFloats.begin(), E = ExpandedFloats.end(); I != E; ++I) { 591 assert(I->first.getNode() != N); 592 RemapValue(I->second.first); 593 RemapValue(I->second.second); 594 } 595 596 for (DenseMap<SDValue, std::pair<SDValue, SDValue> >::iterator 597 I = SplitVectors.begin(), E = SplitVectors.end(); I != E; ++I) { 598 assert(I->first.getNode() != N); 599 RemapValue(I->second.first); 600 RemapValue(I->second.second); 601 } 602 603 for (DenseMap<SDValue, SDValue>::iterator I = ReplacedValues.begin(), 604 E = ReplacedValues.end(); I != E; ++I) 605 RemapValue(I->second); 606 607 for (unsigned i = 0, e = N->getNumValues(); i != e; ++i) 608 ReplacedValues.erase(SDValue(N, i)); 609 } 610 611 /// RemapValue - If the specified value was already legalized to another value, 612 /// replace it by that value. 613 void DAGTypeLegalizer::RemapValue(SDValue &N) { 614 DenseMap<SDValue, SDValue>::iterator I = ReplacedValues.find(N); 615 if (I != ReplacedValues.end()) { 616 // Use path compression to speed up future lookups if values get multiply 617 // replaced with other values. 618 RemapValue(I->second); 619 N = I->second; 620 621 // Note that it is possible to have N.getNode()->getNodeId() == NewNode at 622 // this point because it is possible for a node to be put in the map before 623 // being processed. 624 } 625 } 626 627 namespace { 628 /// NodeUpdateListener - This class is a DAGUpdateListener that listens for 629 /// updates to nodes and recomputes their ready state. 630 class NodeUpdateListener : public SelectionDAG::DAGUpdateListener { 631 DAGTypeLegalizer &DTL; 632 SmallSetVector<SDNode*, 16> &NodesToAnalyze; 633 public: 634 explicit NodeUpdateListener(DAGTypeLegalizer &dtl, 635 SmallSetVector<SDNode*, 16> &nta) 636 : SelectionDAG::DAGUpdateListener(dtl.getDAG()), 637 DTL(dtl), NodesToAnalyze(nta) {} 638 639 void NodeDeleted(SDNode *N, SDNode *E) override { 640 assert(N->getNodeId() != DAGTypeLegalizer::ReadyToProcess && 641 N->getNodeId() != DAGTypeLegalizer::Processed && 642 "Invalid node ID for RAUW deletion!"); 643 // It is possible, though rare, for the deleted node N to occur as a 644 // target in a map, so note the replacement N -> E in ReplacedValues. 645 assert(E && "Node not replaced?"); 646 DTL.NoteDeletion(N, E); 647 648 // In theory the deleted node could also have been scheduled for analysis. 649 // So remove it from the set of nodes which will be analyzed. 650 NodesToAnalyze.remove(N); 651 652 // In general nothing needs to be done for E, since it didn't change but 653 // only gained new uses. However N -> E was just added to ReplacedValues, 654 // and the result of a ReplacedValues mapping is not allowed to be marked 655 // NewNode. So if E is marked NewNode, then it needs to be analyzed. 656 if (E->getNodeId() == DAGTypeLegalizer::NewNode) 657 NodesToAnalyze.insert(E); 658 } 659 660 void NodeUpdated(SDNode *N) override { 661 // Node updates can mean pretty much anything. It is possible that an 662 // operand was set to something already processed (f.e.) in which case 663 // this node could become ready. Recompute its flags. 664 assert(N->getNodeId() != DAGTypeLegalizer::ReadyToProcess && 665 N->getNodeId() != DAGTypeLegalizer::Processed && 666 "Invalid node ID for RAUW deletion!"); 667 N->setNodeId(DAGTypeLegalizer::NewNode); 668 NodesToAnalyze.insert(N); 669 } 670 }; 671 } 672 673 674 /// ReplaceValueWith - The specified value was legalized to the specified other 675 /// value. Update the DAG and NodeIds replacing any uses of From to use To 676 /// instead. 677 void DAGTypeLegalizer::ReplaceValueWith(SDValue From, SDValue To) { 678 assert(From.getNode() != To.getNode() && "Potential legalization loop!"); 679 680 // If expansion produced new nodes, make sure they are properly marked. 681 ExpungeNode(From.getNode()); 682 AnalyzeNewValue(To); // Expunges To. 683 684 // Anything that used the old node should now use the new one. Note that this 685 // can potentially cause recursive merging. 686 SmallSetVector<SDNode*, 16> NodesToAnalyze; 687 NodeUpdateListener NUL(*this, NodesToAnalyze); 688 do { 689 DAG.ReplaceAllUsesOfValueWith(From, To); 690 691 // The old node may still be present in a map like ExpandedIntegers or 692 // PromotedIntegers. Inform maps about the replacement. 693 ReplacedValues[From] = To; 694 695 // Process the list of nodes that need to be reanalyzed. 696 while (!NodesToAnalyze.empty()) { 697 SDNode *N = NodesToAnalyze.back(); 698 NodesToAnalyze.pop_back(); 699 if (N->getNodeId() != DAGTypeLegalizer::NewNode) 700 // The node was analyzed while reanalyzing an earlier node - it is safe 701 // to skip. Note that this is not a morphing node - otherwise it would 702 // still be marked NewNode. 703 continue; 704 705 // Analyze the node's operands and recalculate the node ID. 706 SDNode *M = AnalyzeNewNode(N); 707 if (M != N) { 708 // The node morphed into a different node. Make everyone use the new 709 // node instead. 710 assert(M->getNodeId() != NewNode && "Analysis resulted in NewNode!"); 711 assert(N->getNumValues() == M->getNumValues() && 712 "Node morphing changed the number of results!"); 713 for (unsigned i = 0, e = N->getNumValues(); i != e; ++i) { 714 SDValue OldVal(N, i); 715 SDValue NewVal(M, i); 716 if (M->getNodeId() == Processed) 717 RemapValue(NewVal); 718 DAG.ReplaceAllUsesOfValueWith(OldVal, NewVal); 719 // OldVal may be a target of the ReplacedValues map which was marked 720 // NewNode to force reanalysis because it was updated. Ensure that 721 // anything that ReplacedValues mapped to OldVal will now be mapped 722 // all the way to NewVal. 723 ReplacedValues[OldVal] = NewVal; 724 } 725 // The original node continues to exist in the DAG, marked NewNode. 726 } 727 } 728 // When recursively update nodes with new nodes, it is possible to have 729 // new uses of From due to CSE. If this happens, replace the new uses of 730 // From with To. 731 } while (!From.use_empty()); 732 } 733 734 void DAGTypeLegalizer::SetPromotedInteger(SDValue Op, SDValue Result) { 735 assert(Result.getValueType() == 736 TLI.getTypeToTransformTo(*DAG.getContext(), Op.getValueType()) && 737 "Invalid type for promoted integer"); 738 AnalyzeNewValue(Result); 739 740 SDValue &OpEntry = PromotedIntegers[Op]; 741 assert(!OpEntry.getNode() && "Node is already promoted!"); 742 OpEntry = Result; 743 } 744 745 void DAGTypeLegalizer::SetSoftenedFloat(SDValue Op, SDValue Result) { 746 assert(Result.getValueType() == 747 TLI.getTypeToTransformTo(*DAG.getContext(), Op.getValueType()) && 748 "Invalid type for softened float"); 749 AnalyzeNewValue(Result); 750 751 SDValue &OpEntry = SoftenedFloats[Op]; 752 assert(!OpEntry.getNode() && "Node is already converted to integer!"); 753 OpEntry = Result; 754 } 755 756 void DAGTypeLegalizer::SetScalarizedVector(SDValue Op, SDValue Result) { 757 // Note that in some cases vector operation operands may be greater than 758 // the vector element type. For example BUILD_VECTOR of type <1 x i1> with 759 // a constant i8 operand. 760 assert(Result.getValueType().getSizeInBits() >= 761 Op.getValueType().getVectorElementType().getSizeInBits() && 762 "Invalid type for scalarized vector"); 763 AnalyzeNewValue(Result); 764 765 SDValue &OpEntry = ScalarizedVectors[Op]; 766 assert(!OpEntry.getNode() && "Node is already scalarized!"); 767 OpEntry = Result; 768 } 769 770 void DAGTypeLegalizer::GetExpandedInteger(SDValue Op, SDValue &Lo, 771 SDValue &Hi) { 772 std::pair<SDValue, SDValue> &Entry = ExpandedIntegers[Op]; 773 RemapValue(Entry.first); 774 RemapValue(Entry.second); 775 assert(Entry.first.getNode() && "Operand isn't expanded"); 776 Lo = Entry.first; 777 Hi = Entry.second; 778 } 779 780 void DAGTypeLegalizer::SetExpandedInteger(SDValue Op, SDValue Lo, 781 SDValue Hi) { 782 assert(Lo.getValueType() == 783 TLI.getTypeToTransformTo(*DAG.getContext(), Op.getValueType()) && 784 Hi.getValueType() == Lo.getValueType() && 785 "Invalid type for expanded integer"); 786 // Lo/Hi may have been newly allocated, if so, add nodeid's as relevant. 787 AnalyzeNewValue(Lo); 788 AnalyzeNewValue(Hi); 789 790 // Remember that this is the result of the node. 791 std::pair<SDValue, SDValue> &Entry = ExpandedIntegers[Op]; 792 assert(!Entry.first.getNode() && "Node already expanded"); 793 Entry.first = Lo; 794 Entry.second = Hi; 795 } 796 797 void DAGTypeLegalizer::GetExpandedFloat(SDValue Op, SDValue &Lo, 798 SDValue &Hi) { 799 std::pair<SDValue, SDValue> &Entry = ExpandedFloats[Op]; 800 RemapValue(Entry.first); 801 RemapValue(Entry.second); 802 assert(Entry.first.getNode() && "Operand isn't expanded"); 803 Lo = Entry.first; 804 Hi = Entry.second; 805 } 806 807 void DAGTypeLegalizer::SetExpandedFloat(SDValue Op, SDValue Lo, 808 SDValue Hi) { 809 assert(Lo.getValueType() == 810 TLI.getTypeToTransformTo(*DAG.getContext(), Op.getValueType()) && 811 Hi.getValueType() == Lo.getValueType() && 812 "Invalid type for expanded float"); 813 // Lo/Hi may have been newly allocated, if so, add nodeid's as relevant. 814 AnalyzeNewValue(Lo); 815 AnalyzeNewValue(Hi); 816 817 // Remember that this is the result of the node. 818 std::pair<SDValue, SDValue> &Entry = ExpandedFloats[Op]; 819 assert(!Entry.first.getNode() && "Node already expanded"); 820 Entry.first = Lo; 821 Entry.second = Hi; 822 } 823 824 void DAGTypeLegalizer::GetSplitVector(SDValue Op, SDValue &Lo, 825 SDValue &Hi) { 826 std::pair<SDValue, SDValue> &Entry = SplitVectors[Op]; 827 RemapValue(Entry.first); 828 RemapValue(Entry.second); 829 assert(Entry.first.getNode() && "Operand isn't split"); 830 Lo = Entry.first; 831 Hi = Entry.second; 832 } 833 834 void DAGTypeLegalizer::SetSplitVector(SDValue Op, SDValue Lo, 835 SDValue Hi) { 836 assert(Lo.getValueType().getVectorElementType() == 837 Op.getValueType().getVectorElementType() && 838 2*Lo.getValueType().getVectorNumElements() == 839 Op.getValueType().getVectorNumElements() && 840 Hi.getValueType() == Lo.getValueType() && 841 "Invalid type for split vector"); 842 // Lo/Hi may have been newly allocated, if so, add nodeid's as relevant. 843 AnalyzeNewValue(Lo); 844 AnalyzeNewValue(Hi); 845 846 // Remember that this is the result of the node. 847 std::pair<SDValue, SDValue> &Entry = SplitVectors[Op]; 848 assert(!Entry.first.getNode() && "Node already split"); 849 Entry.first = Lo; 850 Entry.second = Hi; 851 } 852 853 void DAGTypeLegalizer::SetWidenedVector(SDValue Op, SDValue Result) { 854 assert(Result.getValueType() == 855 TLI.getTypeToTransformTo(*DAG.getContext(), Op.getValueType()) && 856 "Invalid type for widened vector"); 857 AnalyzeNewValue(Result); 858 859 SDValue &OpEntry = WidenedVectors[Op]; 860 assert(!OpEntry.getNode() && "Node already widened!"); 861 OpEntry = Result; 862 } 863 864 865 //===----------------------------------------------------------------------===// 866 // Utilities. 867 //===----------------------------------------------------------------------===// 868 869 /// BitConvertToInteger - Convert to an integer of the same size. 870 SDValue DAGTypeLegalizer::BitConvertToInteger(SDValue Op) { 871 unsigned BitWidth = Op.getValueType().getSizeInBits(); 872 return DAG.getNode(ISD::BITCAST, SDLoc(Op), 873 EVT::getIntegerVT(*DAG.getContext(), BitWidth), Op); 874 } 875 876 /// BitConvertVectorToIntegerVector - Convert to a vector of integers of the 877 /// same size. 878 SDValue DAGTypeLegalizer::BitConvertVectorToIntegerVector(SDValue Op) { 879 assert(Op.getValueType().isVector() && "Only applies to vectors!"); 880 unsigned EltWidth = Op.getValueType().getVectorElementType().getSizeInBits(); 881 EVT EltNVT = EVT::getIntegerVT(*DAG.getContext(), EltWidth); 882 unsigned NumElts = Op.getValueType().getVectorNumElements(); 883 return DAG.getNode(ISD::BITCAST, SDLoc(Op), 884 EVT::getVectorVT(*DAG.getContext(), EltNVT, NumElts), Op); 885 } 886 887 SDValue DAGTypeLegalizer::CreateStackStoreLoad(SDValue Op, 888 EVT DestVT) { 889 SDLoc dl(Op); 890 // Create the stack frame object. Make sure it is aligned for both 891 // the source and destination types. 892 SDValue StackPtr = DAG.CreateStackTemporary(Op.getValueType(), DestVT); 893 // Emit a store to the stack slot. 894 SDValue Store = DAG.getStore(DAG.getEntryNode(), dl, Op, StackPtr, 895 MachinePointerInfo(), false, false, 0); 896 // Result is a load from the stack slot. 897 return DAG.getLoad(DestVT, dl, Store, StackPtr, MachinePointerInfo(), 898 false, false, false, 0); 899 } 900 901 /// CustomLowerNode - Replace the node's results with custom code provided 902 /// by the target and return "true", or do nothing and return "false". 903 /// The last parameter is FALSE if we are dealing with a node with legal 904 /// result types and illegal operand. The second parameter denotes the type of 905 /// illegal OperandNo in that case. 906 /// The last parameter being TRUE means we are dealing with a 907 /// node with illegal result types. The second parameter denotes the type of 908 /// illegal ResNo in that case. 909 bool DAGTypeLegalizer::CustomLowerNode(SDNode *N, EVT VT, bool LegalizeResult) { 910 // See if the target wants to custom lower this node. 911 if (TLI.getOperationAction(N->getOpcode(), VT) != TargetLowering::Custom) 912 return false; 913 914 SmallVector<SDValue, 8> Results; 915 if (LegalizeResult) 916 TLI.ReplaceNodeResults(N, Results, DAG); 917 else 918 TLI.LowerOperationWrapper(N, Results, DAG); 919 920 if (Results.empty()) 921 // The target didn't want to custom lower it after all. 922 return false; 923 924 // Make everything that once used N's values now use those in Results instead. 925 assert(Results.size() == N->getNumValues() && 926 "Custom lowering returned the wrong number of results!"); 927 for (unsigned i = 0, e = Results.size(); i != e; ++i) { 928 ReplaceValueWith(SDValue(N, i), Results[i]); 929 } 930 return true; 931 } 932 933 934 /// CustomWidenLowerNode - Widen the node's results with custom code provided 935 /// by the target and return "true", or do nothing and return "false". 936 bool DAGTypeLegalizer::CustomWidenLowerNode(SDNode *N, EVT VT) { 937 // See if the target wants to custom lower this node. 938 if (TLI.getOperationAction(N->getOpcode(), VT) != TargetLowering::Custom) 939 return false; 940 941 SmallVector<SDValue, 8> Results; 942 TLI.ReplaceNodeResults(N, Results, DAG); 943 944 if (Results.empty()) 945 // The target didn't want to custom widen lower its result after all. 946 return false; 947 948 // Update the widening map. 949 assert(Results.size() == N->getNumValues() && 950 "Custom lowering returned the wrong number of results!"); 951 for (unsigned i = 0, e = Results.size(); i != e; ++i) 952 SetWidenedVector(SDValue(N, i), Results[i]); 953 return true; 954 } 955 956 SDValue DAGTypeLegalizer::DisintegrateMERGE_VALUES(SDNode *N, unsigned ResNo) { 957 for (unsigned i = 0, e = N->getNumValues(); i != e; ++i) 958 if (i != ResNo) 959 ReplaceValueWith(SDValue(N, i), SDValue(N->getOperand(i))); 960 return SDValue(N->getOperand(ResNo)); 961 } 962 963 /// GetPairElements - Use ISD::EXTRACT_ELEMENT nodes to extract the low and 964 /// high parts of the given value. 965 void DAGTypeLegalizer::GetPairElements(SDValue Pair, 966 SDValue &Lo, SDValue &Hi) { 967 SDLoc dl(Pair); 968 EVT NVT = TLI.getTypeToTransformTo(*DAG.getContext(), Pair.getValueType()); 969 Lo = DAG.getNode(ISD::EXTRACT_ELEMENT, dl, NVT, Pair, 970 DAG.getIntPtrConstant(0)); 971 Hi = DAG.getNode(ISD::EXTRACT_ELEMENT, dl, NVT, Pair, 972 DAG.getIntPtrConstant(1)); 973 } 974 975 SDValue DAGTypeLegalizer::GetVectorElementPointer(SDValue VecPtr, EVT EltVT, 976 SDValue Index) { 977 SDLoc dl(Index); 978 // Make sure the index type is big enough to compute in. 979 Index = DAG.getZExtOrTrunc(Index, dl, TLI.getPointerTy()); 980 981 // Calculate the element offset and add it to the pointer. 982 unsigned EltSize = EltVT.getSizeInBits() / 8; // FIXME: should be ABI size. 983 984 Index = DAG.getNode(ISD::MUL, dl, Index.getValueType(), Index, 985 DAG.getConstant(EltSize, Index.getValueType())); 986 return DAG.getNode(ISD::ADD, dl, Index.getValueType(), Index, VecPtr); 987 } 988 989 /// JoinIntegers - Build an integer with low bits Lo and high bits Hi. 990 SDValue DAGTypeLegalizer::JoinIntegers(SDValue Lo, SDValue Hi) { 991 // Arbitrarily use dlHi for result SDLoc 992 SDLoc dlHi(Hi); 993 SDLoc dlLo(Lo); 994 EVT LVT = Lo.getValueType(); 995 EVT HVT = Hi.getValueType(); 996 EVT NVT = EVT::getIntegerVT(*DAG.getContext(), 997 LVT.getSizeInBits() + HVT.getSizeInBits()); 998 999 Lo = DAG.getNode(ISD::ZERO_EXTEND, dlLo, NVT, Lo); 1000 Hi = DAG.getNode(ISD::ANY_EXTEND, dlHi, NVT, Hi); 1001 Hi = DAG.getNode(ISD::SHL, dlHi, NVT, Hi, 1002 DAG.getConstant(LVT.getSizeInBits(), TLI.getPointerTy())); 1003 return DAG.getNode(ISD::OR, dlHi, NVT, Lo, Hi); 1004 } 1005 1006 /// LibCallify - Convert the node into a libcall with the same prototype. 1007 SDValue DAGTypeLegalizer::LibCallify(RTLIB::Libcall LC, SDNode *N, 1008 bool isSigned) { 1009 unsigned NumOps = N->getNumOperands(); 1010 SDLoc dl(N); 1011 if (NumOps == 0) { 1012 return TLI.makeLibCall(DAG, LC, N->getValueType(0), nullptr, 0, isSigned, 1013 dl).first; 1014 } else if (NumOps == 1) { 1015 SDValue Op = N->getOperand(0); 1016 return TLI.makeLibCall(DAG, LC, N->getValueType(0), &Op, 1, isSigned, 1017 dl).first; 1018 } else if (NumOps == 2) { 1019 SDValue Ops[2] = { N->getOperand(0), N->getOperand(1) }; 1020 return TLI.makeLibCall(DAG, LC, N->getValueType(0), Ops, 2, isSigned, 1021 dl).first; 1022 } 1023 SmallVector<SDValue, 8> Ops(NumOps); 1024 for (unsigned i = 0; i < NumOps; ++i) 1025 Ops[i] = N->getOperand(i); 1026 1027 return TLI.makeLibCall(DAG, LC, N->getValueType(0), 1028 &Ops[0], NumOps, isSigned, dl).first; 1029 } 1030 1031 // ExpandChainLibCall - Expand a node into a call to a libcall. Similar to 1032 // ExpandLibCall except that the first operand is the in-chain. 1033 std::pair<SDValue, SDValue> 1034 DAGTypeLegalizer::ExpandChainLibCall(RTLIB::Libcall LC, 1035 SDNode *Node, 1036 bool isSigned) { 1037 SDValue InChain = Node->getOperand(0); 1038 1039 TargetLowering::ArgListTy Args; 1040 TargetLowering::ArgListEntry Entry; 1041 for (unsigned i = 1, e = Node->getNumOperands(); i != e; ++i) { 1042 EVT ArgVT = Node->getOperand(i).getValueType(); 1043 Type *ArgTy = ArgVT.getTypeForEVT(*DAG.getContext()); 1044 Entry.Node = Node->getOperand(i); 1045 Entry.Ty = ArgTy; 1046 Entry.isSExt = isSigned; 1047 Entry.isZExt = !isSigned; 1048 Args.push_back(Entry); 1049 } 1050 SDValue Callee = DAG.getExternalSymbol(TLI.getLibcallName(LC), 1051 TLI.getPointerTy()); 1052 1053 Type *RetTy = Node->getValueType(0).getTypeForEVT(*DAG.getContext()); 1054 1055 TargetLowering::CallLoweringInfo CLI(DAG); 1056 CLI.setDebugLoc(SDLoc(Node)).setChain(InChain) 1057 .setCallee(TLI.getLibcallCallingConv(LC), RetTy, Callee, std::move(Args), 0) 1058 .setSExtResult(isSigned).setZExtResult(!isSigned); 1059 1060 std::pair<SDValue, SDValue> CallInfo = TLI.LowerCallTo(CLI); 1061 1062 return CallInfo; 1063 } 1064 1065 /// PromoteTargetBoolean - Promote the given target boolean to a target boolean 1066 /// of the given type. A target boolean is an integer value, not necessarily of 1067 /// type i1, the bits of which conform to getBooleanContents. 1068 /// 1069 /// ValVT is the type of values that produced the boolean. 1070 SDValue DAGTypeLegalizer::PromoteTargetBoolean(SDValue Bool, EVT ValVT) { 1071 SDLoc dl(Bool); 1072 EVT BoolVT = getSetCCResultType(ValVT); 1073 ISD::NodeType ExtendCode = 1074 TargetLowering::getExtendForContent(TLI.getBooleanContents(ValVT)); 1075 return DAG.getNode(ExtendCode, dl, BoolVT, Bool); 1076 } 1077 1078 /// SplitInteger - Return the lower LoVT bits of Op in Lo and the upper HiVT 1079 /// bits in Hi. 1080 void DAGTypeLegalizer::SplitInteger(SDValue Op, 1081 EVT LoVT, EVT HiVT, 1082 SDValue &Lo, SDValue &Hi) { 1083 SDLoc dl(Op); 1084 assert(LoVT.getSizeInBits() + HiVT.getSizeInBits() == 1085 Op.getValueType().getSizeInBits() && "Invalid integer splitting!"); 1086 Lo = DAG.getNode(ISD::TRUNCATE, dl, LoVT, Op); 1087 Hi = DAG.getNode(ISD::SRL, dl, Op.getValueType(), Op, 1088 DAG.getConstant(LoVT.getSizeInBits(), TLI.getPointerTy())); 1089 Hi = DAG.getNode(ISD::TRUNCATE, dl, HiVT, Hi); 1090 } 1091 1092 /// SplitInteger - Return the lower and upper halves of Op's bits in a value 1093 /// type half the size of Op's. 1094 void DAGTypeLegalizer::SplitInteger(SDValue Op, 1095 SDValue &Lo, SDValue &Hi) { 1096 EVT HalfVT = EVT::getIntegerVT(*DAG.getContext(), 1097 Op.getValueType().getSizeInBits()/2); 1098 SplitInteger(Op, HalfVT, HalfVT, Lo, Hi); 1099 } 1100 1101 1102 //===----------------------------------------------------------------------===// 1103 // Entry Point 1104 //===----------------------------------------------------------------------===// 1105 1106 /// LegalizeTypes - This transforms the SelectionDAG into a SelectionDAG that 1107 /// only uses types natively supported by the target. Returns "true" if it made 1108 /// any changes. 1109 /// 1110 /// Note that this is an involved process that may invalidate pointers into 1111 /// the graph. 1112 bool SelectionDAG::LegalizeTypes() { 1113 return DAGTypeLegalizer(*this).run(); 1114 } 1115