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 case TargetLowering::TypePromoteFloat: 263 PromoteFloatResult(N, i); 264 Changed = true; 265 goto NodeDone; 266 } 267 } 268 269 ScanOperands: 270 // Scan the operand list for the node, handling any nodes with operands that 271 // are illegal. 272 { 273 unsigned NumOperands = N->getNumOperands(); 274 bool NeedsReanalyzing = false; 275 unsigned i; 276 for (i = 0; i != NumOperands; ++i) { 277 if (IgnoreNodeResults(N->getOperand(i).getNode())) 278 continue; 279 280 EVT OpVT = N->getOperand(i).getValueType(); 281 switch (getTypeAction(OpVT)) { 282 case TargetLowering::TypeLegal: 283 continue; 284 // The following calls must either replace all of the node's results 285 // using ReplaceValueWith, and return "false"; or update the node's 286 // operands in place, and return "true". 287 case TargetLowering::TypePromoteInteger: 288 NeedsReanalyzing = PromoteIntegerOperand(N, i); 289 Changed = true; 290 break; 291 case TargetLowering::TypeExpandInteger: 292 NeedsReanalyzing = ExpandIntegerOperand(N, i); 293 Changed = true; 294 break; 295 case TargetLowering::TypeSoftenFloat: 296 NeedsReanalyzing = SoftenFloatOperand(N, i); 297 Changed = true; 298 break; 299 case TargetLowering::TypeExpandFloat: 300 NeedsReanalyzing = ExpandFloatOperand(N, i); 301 Changed = true; 302 break; 303 case TargetLowering::TypeScalarizeVector: 304 NeedsReanalyzing = ScalarizeVectorOperand(N, i); 305 Changed = true; 306 break; 307 case TargetLowering::TypeSplitVector: 308 NeedsReanalyzing = SplitVectorOperand(N, i); 309 Changed = true; 310 break; 311 case TargetLowering::TypeWidenVector: 312 NeedsReanalyzing = WidenVectorOperand(N, i); 313 Changed = true; 314 break; 315 case TargetLowering::TypePromoteFloat: 316 NeedsReanalyzing = PromoteFloatOperand(N, i); 317 Changed = true; 318 break; 319 } 320 break; 321 } 322 323 // The sub-method updated N in place. Check to see if any operands are new, 324 // and if so, mark them. If the node needs revisiting, don't add all users 325 // to the worklist etc. 326 if (NeedsReanalyzing) { 327 assert(N->getNodeId() == ReadyToProcess && "Node ID recalculated?"); 328 N->setNodeId(NewNode); 329 // Recompute the NodeId and correct processed operands, adding the node to 330 // the worklist if ready. 331 SDNode *M = AnalyzeNewNode(N); 332 if (M == N) 333 // The node didn't morph - nothing special to do, it will be revisited. 334 continue; 335 336 // The node morphed - this is equivalent to legalizing by replacing every 337 // value of N with the corresponding value of M. So do that now. 338 assert(N->getNumValues() == M->getNumValues() && 339 "Node morphing changed the number of results!"); 340 for (unsigned i = 0, e = N->getNumValues(); i != e; ++i) 341 // Replacing the value takes care of remapping the new value. 342 ReplaceValueWith(SDValue(N, i), SDValue(M, i)); 343 assert(N->getNodeId() == NewNode && "Unexpected node state!"); 344 // The node continues to live on as part of the NewNode fungus that 345 // grows on top of the useful nodes. Nothing more needs to be done 346 // with it - move on to the next node. 347 continue; 348 } 349 350 if (i == NumOperands) { 351 DEBUG(dbgs() << "Legally typed node: "; N->dump(&DAG); dbgs() << "\n"); 352 } 353 } 354 NodeDone: 355 356 // If we reach here, the node was processed, potentially creating new nodes. 357 // Mark it as processed and add its users to the worklist as appropriate. 358 assert(N->getNodeId() == ReadyToProcess && "Node ID recalculated?"); 359 N->setNodeId(Processed); 360 361 for (SDNode::use_iterator UI = N->use_begin(), E = N->use_end(); 362 UI != E; ++UI) { 363 SDNode *User = *UI; 364 int NodeId = User->getNodeId(); 365 366 // This node has two options: it can either be a new node or its Node ID 367 // may be a count of the number of operands it has that are not ready. 368 if (NodeId > 0) { 369 User->setNodeId(NodeId-1); 370 371 // If this was the last use it was waiting on, add it to the ready list. 372 if (NodeId-1 == ReadyToProcess) 373 Worklist.push_back(User); 374 continue; 375 } 376 377 // If this is an unreachable new node, then ignore it. If it ever becomes 378 // reachable by being used by a newly created node then it will be handled 379 // by AnalyzeNewNode. 380 if (NodeId == NewNode) 381 continue; 382 383 // Otherwise, this node is new: this is the first operand of it that 384 // became ready. Its new NodeId is the number of operands it has minus 1 385 // (as this node is now processed). 386 assert(NodeId == Unanalyzed && "Unknown node ID!"); 387 User->setNodeId(User->getNumOperands() - 1); 388 389 // If the node only has a single operand, it is now ready. 390 if (User->getNumOperands() == 1) 391 Worklist.push_back(User); 392 } 393 } 394 395 #ifndef XDEBUG 396 if (EnableExpensiveChecks) 397 #endif 398 PerformExpensiveChecks(); 399 400 // If the root changed (e.g. it was a dead load) update the root. 401 DAG.setRoot(Dummy.getValue()); 402 403 // Remove dead nodes. This is important to do for cleanliness but also before 404 // the checking loop below. Implicit folding by the DAG.getNode operators and 405 // node morphing can cause unreachable nodes to be around with their flags set 406 // to new. 407 DAG.RemoveDeadNodes(); 408 409 // In a debug build, scan all the nodes to make sure we found them all. This 410 // ensures that there are no cycles and that everything got processed. 411 #ifndef NDEBUG 412 for (SelectionDAG::allnodes_iterator I = DAG.allnodes_begin(), 413 E = DAG.allnodes_end(); I != E; ++I) { 414 bool Failed = false; 415 416 // Check that all result types are legal. 417 if (!IgnoreNodeResults(I)) 418 for (unsigned i = 0, NumVals = I->getNumValues(); i < NumVals; ++i) 419 if (!isTypeLegal(I->getValueType(i))) { 420 dbgs() << "Result type " << i << " illegal!\n"; 421 Failed = true; 422 } 423 424 // Check that all operand types are legal. 425 for (unsigned i = 0, NumOps = I->getNumOperands(); i < NumOps; ++i) 426 if (!IgnoreNodeResults(I->getOperand(i).getNode()) && 427 !isTypeLegal(I->getOperand(i).getValueType())) { 428 dbgs() << "Operand type " << i << " illegal!\n"; 429 Failed = true; 430 } 431 432 if (I->getNodeId() != Processed) { 433 if (I->getNodeId() == NewNode) 434 dbgs() << "New node not analyzed?\n"; 435 else if (I->getNodeId() == Unanalyzed) 436 dbgs() << "Unanalyzed node not noticed?\n"; 437 else if (I->getNodeId() > 0) 438 dbgs() << "Operand not processed?\n"; 439 else if (I->getNodeId() == ReadyToProcess) 440 dbgs() << "Not added to worklist?\n"; 441 Failed = true; 442 } 443 444 if (Failed) { 445 I->dump(&DAG); dbgs() << "\n"; 446 llvm_unreachable(nullptr); 447 } 448 } 449 #endif 450 451 return Changed; 452 } 453 454 /// AnalyzeNewNode - The specified node is the root of a subtree of potentially 455 /// new nodes. Correct any processed operands (this may change the node) and 456 /// calculate the NodeId. If the node itself changes to a processed node, it 457 /// is not remapped - the caller needs to take care of this. 458 /// Returns the potentially changed node. 459 SDNode *DAGTypeLegalizer::AnalyzeNewNode(SDNode *N) { 460 // If this was an existing node that is already done, we're done. 461 if (N->getNodeId() != NewNode && N->getNodeId() != Unanalyzed) 462 return N; 463 464 // Remove any stale map entries. 465 ExpungeNode(N); 466 467 // Okay, we know that this node is new. Recursively walk all of its operands 468 // to see if they are new also. The depth of this walk is bounded by the size 469 // of the new tree that was constructed (usually 2-3 nodes), so we don't worry 470 // about revisiting of nodes. 471 // 472 // As we walk the operands, keep track of the number of nodes that are 473 // processed. If non-zero, this will become the new nodeid of this node. 474 // Operands may morph when they are analyzed. If so, the node will be 475 // updated after all operands have been analyzed. Since this is rare, 476 // the code tries to minimize overhead in the non-morphing case. 477 478 SmallVector<SDValue, 8> NewOps; 479 unsigned NumProcessed = 0; 480 for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i) { 481 SDValue OrigOp = N->getOperand(i); 482 SDValue Op = OrigOp; 483 484 AnalyzeNewValue(Op); // Op may morph. 485 486 if (Op.getNode()->getNodeId() == Processed) 487 ++NumProcessed; 488 489 if (!NewOps.empty()) { 490 // Some previous operand changed. Add this one to the list. 491 NewOps.push_back(Op); 492 } else if (Op != OrigOp) { 493 // This is the first operand to change - add all operands so far. 494 NewOps.append(N->op_begin(), N->op_begin() + i); 495 NewOps.push_back(Op); 496 } 497 } 498 499 // Some operands changed - update the node. 500 if (!NewOps.empty()) { 501 SDNode *M = DAG.UpdateNodeOperands(N, NewOps); 502 if (M != N) { 503 // The node morphed into a different node. Normally for this to happen 504 // the original node would have to be marked NewNode. However this can 505 // in theory momentarily not be the case while ReplaceValueWith is doing 506 // its stuff. Mark the original node NewNode to help sanity checking. 507 N->setNodeId(NewNode); 508 if (M->getNodeId() != NewNode && M->getNodeId() != Unanalyzed) 509 // It morphed into a previously analyzed node - nothing more to do. 510 return M; 511 512 // It morphed into a different new node. Do the equivalent of passing 513 // it to AnalyzeNewNode: expunge it and calculate the NodeId. No need 514 // to remap the operands, since they are the same as the operands we 515 // remapped above. 516 N = M; 517 ExpungeNode(N); 518 } 519 } 520 521 // Calculate the NodeId. 522 N->setNodeId(N->getNumOperands() - NumProcessed); 523 if (N->getNodeId() == ReadyToProcess) 524 Worklist.push_back(N); 525 526 return N; 527 } 528 529 /// AnalyzeNewValue - Call AnalyzeNewNode, updating the node in Val if needed. 530 /// If the node changes to a processed node, then remap it. 531 void DAGTypeLegalizer::AnalyzeNewValue(SDValue &Val) { 532 Val.setNode(AnalyzeNewNode(Val.getNode())); 533 if (Val.getNode()->getNodeId() == Processed) 534 // We were passed a processed node, or it morphed into one - remap it. 535 RemapValue(Val); 536 } 537 538 /// ExpungeNode - If N has a bogus mapping in ReplacedValues, eliminate it. 539 /// This can occur when a node is deleted then reallocated as a new node - 540 /// the mapping in ReplacedValues applies to the deleted node, not the new 541 /// one. 542 /// The only map that can have a deleted node as a source is ReplacedValues. 543 /// Other maps can have deleted nodes as targets, but since their looked-up 544 /// values are always immediately remapped using RemapValue, resulting in a 545 /// not-deleted node, this is harmless as long as ReplacedValues/RemapValue 546 /// always performs correct mappings. In order to keep the mapping correct, 547 /// ExpungeNode should be called on any new nodes *before* adding them as 548 /// either source or target to ReplacedValues (which typically means calling 549 /// Expunge when a new node is first seen, since it may no longer be marked 550 /// NewNode by the time it is added to ReplacedValues). 551 void DAGTypeLegalizer::ExpungeNode(SDNode *N) { 552 if (N->getNodeId() != NewNode) 553 return; 554 555 // If N is not remapped by ReplacedValues then there is nothing to do. 556 unsigned i, e; 557 for (i = 0, e = N->getNumValues(); i != e; ++i) 558 if (ReplacedValues.find(SDValue(N, i)) != ReplacedValues.end()) 559 break; 560 561 if (i == e) 562 return; 563 564 // Remove N from all maps - this is expensive but rare. 565 566 for (DenseMap<SDValue, SDValue>::iterator I = PromotedIntegers.begin(), 567 E = PromotedIntegers.end(); I != E; ++I) { 568 assert(I->first.getNode() != N); 569 RemapValue(I->second); 570 } 571 572 for (DenseMap<SDValue, SDValue>::iterator I = SoftenedFloats.begin(), 573 E = SoftenedFloats.end(); I != E; ++I) { 574 assert(I->first.getNode() != N); 575 RemapValue(I->second); 576 } 577 578 for (DenseMap<SDValue, SDValue>::iterator I = ScalarizedVectors.begin(), 579 E = ScalarizedVectors.end(); I != E; ++I) { 580 assert(I->first.getNode() != N); 581 RemapValue(I->second); 582 } 583 584 for (DenseMap<SDValue, SDValue>::iterator I = WidenedVectors.begin(), 585 E = WidenedVectors.end(); I != E; ++I) { 586 assert(I->first.getNode() != N); 587 RemapValue(I->second); 588 } 589 590 for (DenseMap<SDValue, std::pair<SDValue, SDValue> >::iterator 591 I = ExpandedIntegers.begin(), E = ExpandedIntegers.end(); I != E; ++I){ 592 assert(I->first.getNode() != N); 593 RemapValue(I->second.first); 594 RemapValue(I->second.second); 595 } 596 597 for (DenseMap<SDValue, std::pair<SDValue, SDValue> >::iterator 598 I = ExpandedFloats.begin(), E = ExpandedFloats.end(); I != E; ++I) { 599 assert(I->first.getNode() != N); 600 RemapValue(I->second.first); 601 RemapValue(I->second.second); 602 } 603 604 for (DenseMap<SDValue, std::pair<SDValue, SDValue> >::iterator 605 I = SplitVectors.begin(), E = SplitVectors.end(); I != E; ++I) { 606 assert(I->first.getNode() != N); 607 RemapValue(I->second.first); 608 RemapValue(I->second.second); 609 } 610 611 for (DenseMap<SDValue, SDValue>::iterator I = ReplacedValues.begin(), 612 E = ReplacedValues.end(); I != E; ++I) 613 RemapValue(I->second); 614 615 for (unsigned i = 0, e = N->getNumValues(); i != e; ++i) 616 ReplacedValues.erase(SDValue(N, i)); 617 } 618 619 /// RemapValue - If the specified value was already legalized to another value, 620 /// replace it by that value. 621 void DAGTypeLegalizer::RemapValue(SDValue &N) { 622 DenseMap<SDValue, SDValue>::iterator I = ReplacedValues.find(N); 623 if (I != ReplacedValues.end()) { 624 // Use path compression to speed up future lookups if values get multiply 625 // replaced with other values. 626 RemapValue(I->second); 627 N = I->second; 628 629 // Note that it is possible to have N.getNode()->getNodeId() == NewNode at 630 // this point because it is possible for a node to be put in the map before 631 // being processed. 632 } 633 } 634 635 namespace { 636 /// NodeUpdateListener - This class is a DAGUpdateListener that listens for 637 /// updates to nodes and recomputes their ready state. 638 class NodeUpdateListener : public SelectionDAG::DAGUpdateListener { 639 DAGTypeLegalizer &DTL; 640 SmallSetVector<SDNode*, 16> &NodesToAnalyze; 641 public: 642 explicit NodeUpdateListener(DAGTypeLegalizer &dtl, 643 SmallSetVector<SDNode*, 16> &nta) 644 : SelectionDAG::DAGUpdateListener(dtl.getDAG()), 645 DTL(dtl), NodesToAnalyze(nta) {} 646 647 void NodeDeleted(SDNode *N, SDNode *E) override { 648 assert(N->getNodeId() != DAGTypeLegalizer::ReadyToProcess && 649 N->getNodeId() != DAGTypeLegalizer::Processed && 650 "Invalid node ID for RAUW deletion!"); 651 // It is possible, though rare, for the deleted node N to occur as a 652 // target in a map, so note the replacement N -> E in ReplacedValues. 653 assert(E && "Node not replaced?"); 654 DTL.NoteDeletion(N, E); 655 656 // In theory the deleted node could also have been scheduled for analysis. 657 // So remove it from the set of nodes which will be analyzed. 658 NodesToAnalyze.remove(N); 659 660 // In general nothing needs to be done for E, since it didn't change but 661 // only gained new uses. However N -> E was just added to ReplacedValues, 662 // and the result of a ReplacedValues mapping is not allowed to be marked 663 // NewNode. So if E is marked NewNode, then it needs to be analyzed. 664 if (E->getNodeId() == DAGTypeLegalizer::NewNode) 665 NodesToAnalyze.insert(E); 666 } 667 668 void NodeUpdated(SDNode *N) override { 669 // Node updates can mean pretty much anything. It is possible that an 670 // operand was set to something already processed (f.e.) in which case 671 // this node could become ready. Recompute its flags. 672 assert(N->getNodeId() != DAGTypeLegalizer::ReadyToProcess && 673 N->getNodeId() != DAGTypeLegalizer::Processed && 674 "Invalid node ID for RAUW deletion!"); 675 N->setNodeId(DAGTypeLegalizer::NewNode); 676 NodesToAnalyze.insert(N); 677 } 678 }; 679 } 680 681 682 /// ReplaceValueWith - The specified value was legalized to the specified other 683 /// value. Update the DAG and NodeIds replacing any uses of From to use To 684 /// instead. 685 void DAGTypeLegalizer::ReplaceValueWith(SDValue From, SDValue To) { 686 assert(From.getNode() != To.getNode() && "Potential legalization loop!"); 687 688 // If expansion produced new nodes, make sure they are properly marked. 689 ExpungeNode(From.getNode()); 690 AnalyzeNewValue(To); // Expunges To. 691 692 // Anything that used the old node should now use the new one. Note that this 693 // can potentially cause recursive merging. 694 SmallSetVector<SDNode*, 16> NodesToAnalyze; 695 NodeUpdateListener NUL(*this, NodesToAnalyze); 696 do { 697 DAG.ReplaceAllUsesOfValueWith(From, To); 698 699 // The old node may still be present in a map like ExpandedIntegers or 700 // PromotedIntegers. Inform maps about the replacement. 701 ReplacedValues[From] = To; 702 703 // Process the list of nodes that need to be reanalyzed. 704 while (!NodesToAnalyze.empty()) { 705 SDNode *N = NodesToAnalyze.back(); 706 NodesToAnalyze.pop_back(); 707 if (N->getNodeId() != DAGTypeLegalizer::NewNode) 708 // The node was analyzed while reanalyzing an earlier node - it is safe 709 // to skip. Note that this is not a morphing node - otherwise it would 710 // still be marked NewNode. 711 continue; 712 713 // Analyze the node's operands and recalculate the node ID. 714 SDNode *M = AnalyzeNewNode(N); 715 if (M != N) { 716 // The node morphed into a different node. Make everyone use the new 717 // node instead. 718 assert(M->getNodeId() != NewNode && "Analysis resulted in NewNode!"); 719 assert(N->getNumValues() == M->getNumValues() && 720 "Node morphing changed the number of results!"); 721 for (unsigned i = 0, e = N->getNumValues(); i != e; ++i) { 722 SDValue OldVal(N, i); 723 SDValue NewVal(M, i); 724 if (M->getNodeId() == Processed) 725 RemapValue(NewVal); 726 DAG.ReplaceAllUsesOfValueWith(OldVal, NewVal); 727 // OldVal may be a target of the ReplacedValues map which was marked 728 // NewNode to force reanalysis because it was updated. Ensure that 729 // anything that ReplacedValues mapped to OldVal will now be mapped 730 // all the way to NewVal. 731 ReplacedValues[OldVal] = NewVal; 732 } 733 // The original node continues to exist in the DAG, marked NewNode. 734 } 735 } 736 // When recursively update nodes with new nodes, it is possible to have 737 // new uses of From due to CSE. If this happens, replace the new uses of 738 // From with To. 739 } while (!From.use_empty()); 740 } 741 742 void DAGTypeLegalizer::SetPromotedInteger(SDValue Op, SDValue Result) { 743 assert(Result.getValueType() == 744 TLI.getTypeToTransformTo(*DAG.getContext(), Op.getValueType()) && 745 "Invalid type for promoted integer"); 746 AnalyzeNewValue(Result); 747 748 SDValue &OpEntry = PromotedIntegers[Op]; 749 assert(!OpEntry.getNode() && "Node is already promoted!"); 750 OpEntry = Result; 751 } 752 753 void DAGTypeLegalizer::SetSoftenedFloat(SDValue Op, SDValue Result) { 754 assert(Result.getValueType() == 755 TLI.getTypeToTransformTo(*DAG.getContext(), Op.getValueType()) && 756 "Invalid type for softened float"); 757 AnalyzeNewValue(Result); 758 759 SDValue &OpEntry = SoftenedFloats[Op]; 760 assert(!OpEntry.getNode() && "Node is already converted to integer!"); 761 OpEntry = Result; 762 } 763 764 void DAGTypeLegalizer::SetPromotedFloat(SDValue Op, SDValue Result) { 765 assert(Result.getValueType() == 766 TLI.getTypeToTransformTo(*DAG.getContext(), Op.getValueType()) && 767 "Invalid type for promoted float"); 768 AnalyzeNewValue(Result); 769 770 SDValue &OpEntry = PromotedFloats[Op]; 771 assert(!OpEntry.getNode() && "Node is already promoted!"); 772 OpEntry = Result; 773 } 774 775 void DAGTypeLegalizer::SetScalarizedVector(SDValue Op, SDValue Result) { 776 // Note that in some cases vector operation operands may be greater than 777 // the vector element type. For example BUILD_VECTOR of type <1 x i1> with 778 // a constant i8 operand. 779 assert(Result.getValueType().getSizeInBits() >= 780 Op.getValueType().getVectorElementType().getSizeInBits() && 781 "Invalid type for scalarized vector"); 782 AnalyzeNewValue(Result); 783 784 SDValue &OpEntry = ScalarizedVectors[Op]; 785 assert(!OpEntry.getNode() && "Node is already scalarized!"); 786 OpEntry = Result; 787 } 788 789 void DAGTypeLegalizer::GetExpandedInteger(SDValue Op, SDValue &Lo, 790 SDValue &Hi) { 791 std::pair<SDValue, SDValue> &Entry = ExpandedIntegers[Op]; 792 RemapValue(Entry.first); 793 RemapValue(Entry.second); 794 assert(Entry.first.getNode() && "Operand isn't expanded"); 795 Lo = Entry.first; 796 Hi = Entry.second; 797 } 798 799 void DAGTypeLegalizer::SetExpandedInteger(SDValue Op, SDValue Lo, 800 SDValue Hi) { 801 assert(Lo.getValueType() == 802 TLI.getTypeToTransformTo(*DAG.getContext(), Op.getValueType()) && 803 Hi.getValueType() == Lo.getValueType() && 804 "Invalid type for expanded integer"); 805 // Lo/Hi may have been newly allocated, if so, add nodeid's as relevant. 806 AnalyzeNewValue(Lo); 807 AnalyzeNewValue(Hi); 808 809 // Remember that this is the result of the node. 810 std::pair<SDValue, SDValue> &Entry = ExpandedIntegers[Op]; 811 assert(!Entry.first.getNode() && "Node already expanded"); 812 Entry.first = Lo; 813 Entry.second = Hi; 814 } 815 816 void DAGTypeLegalizer::GetExpandedFloat(SDValue Op, SDValue &Lo, 817 SDValue &Hi) { 818 std::pair<SDValue, SDValue> &Entry = ExpandedFloats[Op]; 819 RemapValue(Entry.first); 820 RemapValue(Entry.second); 821 assert(Entry.first.getNode() && "Operand isn't expanded"); 822 Lo = Entry.first; 823 Hi = Entry.second; 824 } 825 826 void DAGTypeLegalizer::SetExpandedFloat(SDValue Op, SDValue Lo, 827 SDValue Hi) { 828 assert(Lo.getValueType() == 829 TLI.getTypeToTransformTo(*DAG.getContext(), Op.getValueType()) && 830 Hi.getValueType() == Lo.getValueType() && 831 "Invalid type for expanded float"); 832 // Lo/Hi may have been newly allocated, if so, add nodeid's as relevant. 833 AnalyzeNewValue(Lo); 834 AnalyzeNewValue(Hi); 835 836 // Remember that this is the result of the node. 837 std::pair<SDValue, SDValue> &Entry = ExpandedFloats[Op]; 838 assert(!Entry.first.getNode() && "Node already expanded"); 839 Entry.first = Lo; 840 Entry.second = Hi; 841 } 842 843 void DAGTypeLegalizer::GetSplitVector(SDValue Op, SDValue &Lo, 844 SDValue &Hi) { 845 std::pair<SDValue, SDValue> &Entry = SplitVectors[Op]; 846 RemapValue(Entry.first); 847 RemapValue(Entry.second); 848 assert(Entry.first.getNode() && "Operand isn't split"); 849 Lo = Entry.first; 850 Hi = Entry.second; 851 } 852 853 void DAGTypeLegalizer::SetSplitVector(SDValue Op, SDValue Lo, 854 SDValue Hi) { 855 assert(Lo.getValueType().getVectorElementType() == 856 Op.getValueType().getVectorElementType() && 857 2*Lo.getValueType().getVectorNumElements() == 858 Op.getValueType().getVectorNumElements() && 859 Hi.getValueType() == Lo.getValueType() && 860 "Invalid type for split vector"); 861 // Lo/Hi may have been newly allocated, if so, add nodeid's as relevant. 862 AnalyzeNewValue(Lo); 863 AnalyzeNewValue(Hi); 864 865 // Remember that this is the result of the node. 866 std::pair<SDValue, SDValue> &Entry = SplitVectors[Op]; 867 assert(!Entry.first.getNode() && "Node already split"); 868 Entry.first = Lo; 869 Entry.second = Hi; 870 } 871 872 void DAGTypeLegalizer::SetWidenedVector(SDValue Op, SDValue Result) { 873 assert(Result.getValueType() == 874 TLI.getTypeToTransformTo(*DAG.getContext(), Op.getValueType()) && 875 "Invalid type for widened vector"); 876 AnalyzeNewValue(Result); 877 878 SDValue &OpEntry = WidenedVectors[Op]; 879 assert(!OpEntry.getNode() && "Node already widened!"); 880 OpEntry = Result; 881 } 882 883 884 //===----------------------------------------------------------------------===// 885 // Utilities. 886 //===----------------------------------------------------------------------===// 887 888 /// BitConvertToInteger - Convert to an integer of the same size. 889 SDValue DAGTypeLegalizer::BitConvertToInteger(SDValue Op) { 890 unsigned BitWidth = Op.getValueType().getSizeInBits(); 891 return DAG.getNode(ISD::BITCAST, SDLoc(Op), 892 EVT::getIntegerVT(*DAG.getContext(), BitWidth), Op); 893 } 894 895 /// BitConvertVectorToIntegerVector - Convert to a vector of integers of the 896 /// same size. 897 SDValue DAGTypeLegalizer::BitConvertVectorToIntegerVector(SDValue Op) { 898 assert(Op.getValueType().isVector() && "Only applies to vectors!"); 899 unsigned EltWidth = Op.getValueType().getVectorElementType().getSizeInBits(); 900 EVT EltNVT = EVT::getIntegerVT(*DAG.getContext(), EltWidth); 901 unsigned NumElts = Op.getValueType().getVectorNumElements(); 902 return DAG.getNode(ISD::BITCAST, SDLoc(Op), 903 EVT::getVectorVT(*DAG.getContext(), EltNVT, NumElts), Op); 904 } 905 906 SDValue DAGTypeLegalizer::CreateStackStoreLoad(SDValue Op, 907 EVT DestVT) { 908 SDLoc dl(Op); 909 // Create the stack frame object. Make sure it is aligned for both 910 // the source and destination types. 911 SDValue StackPtr = DAG.CreateStackTemporary(Op.getValueType(), DestVT); 912 // Emit a store to the stack slot. 913 SDValue Store = DAG.getStore(DAG.getEntryNode(), dl, Op, StackPtr, 914 MachinePointerInfo(), false, false, 0); 915 // Result is a load from the stack slot. 916 return DAG.getLoad(DestVT, dl, Store, StackPtr, MachinePointerInfo(), 917 false, false, false, 0); 918 } 919 920 /// CustomLowerNode - Replace the node's results with custom code provided 921 /// by the target and return "true", or do nothing and return "false". 922 /// The last parameter is FALSE if we are dealing with a node with legal 923 /// result types and illegal operand. The second parameter denotes the type of 924 /// illegal OperandNo in that case. 925 /// The last parameter being TRUE means we are dealing with a 926 /// node with illegal result types. The second parameter denotes the type of 927 /// illegal ResNo in that case. 928 bool DAGTypeLegalizer::CustomLowerNode(SDNode *N, EVT VT, bool LegalizeResult) { 929 // See if the target wants to custom lower this node. 930 if (TLI.getOperationAction(N->getOpcode(), VT) != TargetLowering::Custom) 931 return false; 932 933 SmallVector<SDValue, 8> Results; 934 if (LegalizeResult) 935 TLI.ReplaceNodeResults(N, Results, DAG); 936 else 937 TLI.LowerOperationWrapper(N, Results, DAG); 938 939 if (Results.empty()) 940 // The target didn't want to custom lower it after all. 941 return false; 942 943 // When called from DAGTypeLegalizer::ExpandIntegerResult, we might need to 944 // provide the same kind of custom splitting behavior. 945 if (Results.size() == N->getNumValues() + 1 && LegalizeResult) { 946 // We've legalized a return type by splitting it. If there is a chain, 947 // replace that too. 948 SetExpandedInteger(SDValue(N, 0), Results[0], Results[1]); 949 if (N->getNumValues() > 1) 950 ReplaceValueWith(SDValue(N, 1), Results[2]); 951 return true; 952 } 953 954 // Make everything that once used N's values now use those in Results instead. 955 assert(Results.size() == N->getNumValues() && 956 "Custom lowering returned the wrong number of results!"); 957 for (unsigned i = 0, e = Results.size(); i != e; ++i) { 958 ReplaceValueWith(SDValue(N, i), Results[i]); 959 } 960 return true; 961 } 962 963 964 /// CustomWidenLowerNode - Widen the node's results with custom code provided 965 /// by the target and return "true", or do nothing and return "false". 966 bool DAGTypeLegalizer::CustomWidenLowerNode(SDNode *N, EVT VT) { 967 // See if the target wants to custom lower this node. 968 if (TLI.getOperationAction(N->getOpcode(), VT) != TargetLowering::Custom) 969 return false; 970 971 SmallVector<SDValue, 8> Results; 972 TLI.ReplaceNodeResults(N, Results, DAG); 973 974 if (Results.empty()) 975 // The target didn't want to custom widen lower its result after all. 976 return false; 977 978 // Update the widening map. 979 assert(Results.size() == N->getNumValues() && 980 "Custom lowering returned the wrong number of results!"); 981 for (unsigned i = 0, e = Results.size(); i != e; ++i) 982 SetWidenedVector(SDValue(N, i), Results[i]); 983 return true; 984 } 985 986 SDValue DAGTypeLegalizer::DisintegrateMERGE_VALUES(SDNode *N, unsigned ResNo) { 987 for (unsigned i = 0, e = N->getNumValues(); i != e; ++i) 988 if (i != ResNo) 989 ReplaceValueWith(SDValue(N, i), SDValue(N->getOperand(i))); 990 return SDValue(N->getOperand(ResNo)); 991 } 992 993 /// GetPairElements - Use ISD::EXTRACT_ELEMENT nodes to extract the low and 994 /// high parts of the given value. 995 void DAGTypeLegalizer::GetPairElements(SDValue Pair, 996 SDValue &Lo, SDValue &Hi) { 997 SDLoc dl(Pair); 998 EVT NVT = TLI.getTypeToTransformTo(*DAG.getContext(), Pair.getValueType()); 999 Lo = DAG.getNode(ISD::EXTRACT_ELEMENT, dl, NVT, Pair, 1000 DAG.getIntPtrConstant(0)); 1001 Hi = DAG.getNode(ISD::EXTRACT_ELEMENT, dl, NVT, Pair, 1002 DAG.getIntPtrConstant(1)); 1003 } 1004 1005 SDValue DAGTypeLegalizer::GetVectorElementPointer(SDValue VecPtr, EVT EltVT, 1006 SDValue Index) { 1007 SDLoc dl(Index); 1008 // Make sure the index type is big enough to compute in. 1009 Index = DAG.getZExtOrTrunc(Index, dl, TLI.getPointerTy()); 1010 1011 // Calculate the element offset and add it to the pointer. 1012 unsigned EltSize = EltVT.getSizeInBits() / 8; // FIXME: should be ABI size. 1013 1014 Index = DAG.getNode(ISD::MUL, dl, Index.getValueType(), Index, 1015 DAG.getConstant(EltSize, Index.getValueType())); 1016 return DAG.getNode(ISD::ADD, dl, Index.getValueType(), Index, VecPtr); 1017 } 1018 1019 /// JoinIntegers - Build an integer with low bits Lo and high bits Hi. 1020 SDValue DAGTypeLegalizer::JoinIntegers(SDValue Lo, SDValue Hi) { 1021 // Arbitrarily use dlHi for result SDLoc 1022 SDLoc dlHi(Hi); 1023 SDLoc dlLo(Lo); 1024 EVT LVT = Lo.getValueType(); 1025 EVT HVT = Hi.getValueType(); 1026 EVT NVT = EVT::getIntegerVT(*DAG.getContext(), 1027 LVT.getSizeInBits() + HVT.getSizeInBits()); 1028 1029 Lo = DAG.getNode(ISD::ZERO_EXTEND, dlLo, NVT, Lo); 1030 Hi = DAG.getNode(ISD::ANY_EXTEND, dlHi, NVT, Hi); 1031 Hi = DAG.getNode(ISD::SHL, dlHi, NVT, Hi, 1032 DAG.getConstant(LVT.getSizeInBits(), TLI.getPointerTy())); 1033 return DAG.getNode(ISD::OR, dlHi, NVT, Lo, Hi); 1034 } 1035 1036 /// LibCallify - Convert the node into a libcall with the same prototype. 1037 SDValue DAGTypeLegalizer::LibCallify(RTLIB::Libcall LC, SDNode *N, 1038 bool isSigned) { 1039 unsigned NumOps = N->getNumOperands(); 1040 SDLoc dl(N); 1041 if (NumOps == 0) { 1042 return TLI.makeLibCall(DAG, LC, N->getValueType(0), nullptr, 0, isSigned, 1043 dl).first; 1044 } else if (NumOps == 1) { 1045 SDValue Op = N->getOperand(0); 1046 return TLI.makeLibCall(DAG, LC, N->getValueType(0), &Op, 1, isSigned, 1047 dl).first; 1048 } else if (NumOps == 2) { 1049 SDValue Ops[2] = { N->getOperand(0), N->getOperand(1) }; 1050 return TLI.makeLibCall(DAG, LC, N->getValueType(0), Ops, 2, isSigned, 1051 dl).first; 1052 } 1053 SmallVector<SDValue, 8> Ops(NumOps); 1054 for (unsigned i = 0; i < NumOps; ++i) 1055 Ops[i] = N->getOperand(i); 1056 1057 return TLI.makeLibCall(DAG, LC, N->getValueType(0), 1058 &Ops[0], NumOps, isSigned, dl).first; 1059 } 1060 1061 // ExpandChainLibCall - Expand a node into a call to a libcall. Similar to 1062 // ExpandLibCall except that the first operand is the in-chain. 1063 std::pair<SDValue, SDValue> 1064 DAGTypeLegalizer::ExpandChainLibCall(RTLIB::Libcall LC, 1065 SDNode *Node, 1066 bool isSigned) { 1067 SDValue InChain = Node->getOperand(0); 1068 1069 TargetLowering::ArgListTy Args; 1070 TargetLowering::ArgListEntry Entry; 1071 for (unsigned i = 1, e = Node->getNumOperands(); i != e; ++i) { 1072 EVT ArgVT = Node->getOperand(i).getValueType(); 1073 Type *ArgTy = ArgVT.getTypeForEVT(*DAG.getContext()); 1074 Entry.Node = Node->getOperand(i); 1075 Entry.Ty = ArgTy; 1076 Entry.isSExt = isSigned; 1077 Entry.isZExt = !isSigned; 1078 Args.push_back(Entry); 1079 } 1080 SDValue Callee = DAG.getExternalSymbol(TLI.getLibcallName(LC), 1081 TLI.getPointerTy()); 1082 1083 Type *RetTy = Node->getValueType(0).getTypeForEVT(*DAG.getContext()); 1084 1085 TargetLowering::CallLoweringInfo CLI(DAG); 1086 CLI.setDebugLoc(SDLoc(Node)).setChain(InChain) 1087 .setCallee(TLI.getLibcallCallingConv(LC), RetTy, Callee, std::move(Args), 0) 1088 .setSExtResult(isSigned).setZExtResult(!isSigned); 1089 1090 std::pair<SDValue, SDValue> CallInfo = TLI.LowerCallTo(CLI); 1091 1092 return CallInfo; 1093 } 1094 1095 /// PromoteTargetBoolean - Promote the given target boolean to a target boolean 1096 /// of the given type. A target boolean is an integer value, not necessarily of 1097 /// type i1, the bits of which conform to getBooleanContents. 1098 /// 1099 /// ValVT is the type of values that produced the boolean. 1100 SDValue DAGTypeLegalizer::PromoteTargetBoolean(SDValue Bool, EVT ValVT) { 1101 SDLoc dl(Bool); 1102 EVT BoolVT = getSetCCResultType(ValVT); 1103 ISD::NodeType ExtendCode = 1104 TargetLowering::getExtendForContent(TLI.getBooleanContents(ValVT)); 1105 return DAG.getNode(ExtendCode, dl, BoolVT, Bool); 1106 } 1107 1108 /// SplitInteger - Return the lower LoVT bits of Op in Lo and the upper HiVT 1109 /// bits in Hi. 1110 void DAGTypeLegalizer::SplitInteger(SDValue Op, 1111 EVT LoVT, EVT HiVT, 1112 SDValue &Lo, SDValue &Hi) { 1113 SDLoc dl(Op); 1114 assert(LoVT.getSizeInBits() + HiVT.getSizeInBits() == 1115 Op.getValueType().getSizeInBits() && "Invalid integer splitting!"); 1116 Lo = DAG.getNode(ISD::TRUNCATE, dl, LoVT, Op); 1117 Hi = DAG.getNode(ISD::SRL, dl, Op.getValueType(), Op, 1118 DAG.getConstant(LoVT.getSizeInBits(), TLI.getPointerTy())); 1119 Hi = DAG.getNode(ISD::TRUNCATE, dl, HiVT, Hi); 1120 } 1121 1122 /// SplitInteger - Return the lower and upper halves of Op's bits in a value 1123 /// type half the size of Op's. 1124 void DAGTypeLegalizer::SplitInteger(SDValue Op, 1125 SDValue &Lo, SDValue &Hi) { 1126 EVT HalfVT = EVT::getIntegerVT(*DAG.getContext(), 1127 Op.getValueType().getSizeInBits()/2); 1128 SplitInteger(Op, HalfVT, HalfVT, Lo, Hi); 1129 } 1130 1131 1132 //===----------------------------------------------------------------------===// 1133 // Entry Point 1134 //===----------------------------------------------------------------------===// 1135 1136 /// LegalizeTypes - This transforms the SelectionDAG into a SelectionDAG that 1137 /// only uses types natively supported by the target. Returns "true" if it made 1138 /// any changes. 1139 /// 1140 /// Note that this is an involved process that may invalidate pointers into 1141 /// the graph. 1142 bool SelectionDAG::LegalizeTypes() { 1143 return DAGTypeLegalizer(*this).run(); 1144 } 1145