LegalizeTypes.cpp revision 223017
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/CallingConv.h" 18#include "llvm/Target/TargetData.h" 19#include "llvm/ADT/SetVector.h" 20#include "llvm/Support/CommandLine.h" 21#include "llvm/Support/ErrorHandling.h" 22#include "llvm/Support/raw_ostream.h" 23using namespace llvm; 24 25static cl::opt<bool> 26EnableExpensiveChecks("enable-legalize-types-checking", cl::Hidden); 27 28/// PerformExpensiveChecks - Do extensive, expensive, sanity checking. 29void DAGTypeLegalizer::PerformExpensiveChecks() { 30 // If a node is not processed, then none of its values should be mapped by any 31 // of PromotedIntegers, ExpandedIntegers, ..., ReplacedValues. 32 33 // If a node is processed, then each value with an illegal type must be mapped 34 // by exactly one of PromotedIntegers, ExpandedIntegers, ..., ReplacedValues. 35 // Values with a legal type may be mapped by ReplacedValues, but not by any of 36 // the other maps. 37 38 // Note that these invariants may not hold momentarily when processing a node: 39 // the node being processed may be put in a map before being marked Processed. 40 41 // Note that it is possible to have nodes marked NewNode in the DAG. This can 42 // occur in two ways. Firstly, a node may be created during legalization but 43 // never passed to the legalization core. This is usually due to the implicit 44 // folding that occurs when using the DAG.getNode operators. Secondly, a new 45 // node may be passed to the legalization core, but when analyzed may morph 46 // into a different node, leaving the original node as a NewNode in the DAG. 47 // A node may morph if one of its operands changes during analysis. Whether 48 // it actually morphs or not depends on whether, after updating its operands, 49 // it is equivalent to an existing node: if so, it morphs into that existing 50 // node (CSE). An operand can change during analysis if the operand is a new 51 // node that morphs, or it is a processed value that was mapped to some other 52 // value (as recorded in ReplacedValues) in which case the operand is turned 53 // into that other value. If a node morphs then the node it morphed into will 54 // be used instead of it for legalization, however the original node continues 55 // to live on in the DAG. 56 // The conclusion is that though there may be nodes marked NewNode in the DAG, 57 // all uses of such nodes are also marked NewNode: the result is a fungus of 58 // NewNodes growing on top of the useful nodes, and perhaps using them, but 59 // not used by them. 60 61 // If a value is mapped by ReplacedValues, then it must have no uses, except 62 // by nodes marked NewNode (see above). 63 64 // The final node obtained by mapping by ReplacedValues is not marked NewNode. 65 // Note that ReplacedValues should be applied iteratively. 66 67 // Note that the ReplacedValues map may also map deleted nodes (by iterating 68 // over the DAG we never dereference deleted nodes). This means that it may 69 // also map nodes marked NewNode if the deallocated memory was reallocated as 70 // another node, and that new node was not seen by the LegalizeTypes machinery 71 // (for example because it was created but not used). In general, we cannot 72 // distinguish between new nodes and deleted nodes. 73 SmallVector<SDNode*, 16> NewNodes; 74 for (SelectionDAG::allnodes_iterator I = DAG.allnodes_begin(), 75 E = DAG.allnodes_end(); I != E; ++I) { 76 // Remember nodes marked NewNode - they are subject to extra checking below. 77 if (I->getNodeId() == NewNode) 78 NewNodes.push_back(I); 79 80 for (unsigned i = 0, e = I->getNumValues(); i != e; ++i) { 81 SDValue Res(I, i); 82 bool Failed = false; 83 84 unsigned Mapped = 0; 85 if (ReplacedValues.find(Res) != ReplacedValues.end()) { 86 Mapped |= 1; 87 // Check that remapped values are only used by nodes marked NewNode. 88 for (SDNode::use_iterator UI = I->use_begin(), UE = I->use_end(); 89 UI != UE; ++UI) 90 if (UI.getUse().getResNo() == i) 91 assert(UI->getNodeId() == NewNode && 92 "Remapped value has non-trivial use!"); 93 94 // Check that the final result of applying ReplacedValues is not 95 // marked NewNode. 96 SDValue NewVal = ReplacedValues[Res]; 97 DenseMap<SDValue, SDValue>::iterator I = ReplacedValues.find(NewVal); 98 while (I != ReplacedValues.end()) { 99 NewVal = I->second; 100 I = ReplacedValues.find(NewVal); 101 } 102 assert(NewVal.getNode()->getNodeId() != NewNode && 103 "ReplacedValues maps to a new node!"); 104 } 105 if (PromotedIntegers.find(Res) != PromotedIntegers.end()) 106 Mapped |= 2; 107 if (SoftenedFloats.find(Res) != SoftenedFloats.end()) 108 Mapped |= 4; 109 if (ScalarizedVectors.find(Res) != ScalarizedVectors.end()) 110 Mapped |= 8; 111 if (ExpandedIntegers.find(Res) != ExpandedIntegers.end()) 112 Mapped |= 16; 113 if (ExpandedFloats.find(Res) != ExpandedFloats.end()) 114 Mapped |= 32; 115 if (SplitVectors.find(Res) != SplitVectors.end()) 116 Mapped |= 64; 117 if (WidenedVectors.find(Res) != WidenedVectors.end()) 118 Mapped |= 128; 119 120 if (I->getNodeId() != Processed) { 121 // Since we allow ReplacedValues to map deleted nodes, it may map nodes 122 // marked NewNode too, since a deleted node may have been reallocated as 123 // another node that has not been seen by the LegalizeTypes machinery. 124 if ((I->getNodeId() == NewNode && Mapped > 1) || 125 (I->getNodeId() != NewNode && Mapped != 0)) { 126 dbgs() << "Unprocessed value in a map!"; 127 Failed = true; 128 } 129 } else if (isTypeLegal(Res.getValueType()) || IgnoreNodeResults(I)) { 130 if (Mapped > 1) { 131 dbgs() << "Value with legal type was transformed!"; 132 Failed = true; 133 } 134 } else { 135 if (Mapped == 0) { 136 dbgs() << "Processed value not in any map!"; 137 Failed = true; 138 } else if (Mapped & (Mapped - 1)) { 139 dbgs() << "Value in multiple maps!"; 140 Failed = true; 141 } 142 } 143 144 if (Failed) { 145 if (Mapped & 1) 146 dbgs() << " ReplacedValues"; 147 if (Mapped & 2) 148 dbgs() << " PromotedIntegers"; 149 if (Mapped & 4) 150 dbgs() << " SoftenedFloats"; 151 if (Mapped & 8) 152 dbgs() << " ScalarizedVectors"; 153 if (Mapped & 16) 154 dbgs() << " ExpandedIntegers"; 155 if (Mapped & 32) 156 dbgs() << " ExpandedFloats"; 157 if (Mapped & 64) 158 dbgs() << " SplitVectors"; 159 if (Mapped & 128) 160 dbgs() << " WidenedVectors"; 161 dbgs() << "\n"; 162 llvm_unreachable(0); 163 } 164 } 165 } 166 167 // Checked that NewNodes are only used by other NewNodes. 168 for (unsigned i = 0, e = NewNodes.size(); i != e; ++i) { 169 SDNode *N = NewNodes[i]; 170 for (SDNode::use_iterator UI = N->use_begin(), UE = N->use_end(); 171 UI != UE; ++UI) 172 assert(UI->getNodeId() == NewNode && "NewNode used by non-NewNode!"); 173 } 174} 175 176/// run - This is the main entry point for the type legalizer. This does a 177/// top-down traversal of the dag, legalizing types as it goes. Returns "true" 178/// if it made any changes. 179bool DAGTypeLegalizer::run() { 180 bool Changed = false; 181 182 // Create a dummy node (which is not added to allnodes), that adds a reference 183 // to the root node, preventing it from being deleted, and tracking any 184 // changes of the root. 185 HandleSDNode Dummy(DAG.getRoot()); 186 Dummy.setNodeId(Unanalyzed); 187 188 // The root of the dag may dangle to deleted nodes until the type legalizer is 189 // done. Set it to null to avoid confusion. 190 DAG.setRoot(SDValue()); 191 192 // Walk all nodes in the graph, assigning them a NodeId of 'ReadyToProcess' 193 // (and remembering them) if they are leaves and assigning 'Unanalyzed' if 194 // non-leaves. 195 for (SelectionDAG::allnodes_iterator I = DAG.allnodes_begin(), 196 E = DAG.allnodes_end(); I != E; ++I) { 197 if (I->getNumOperands() == 0) { 198 I->setNodeId(ReadyToProcess); 199 Worklist.push_back(I); 200 } else { 201 I->setNodeId(Unanalyzed); 202 } 203 } 204 205 // Now that we have a set of nodes to process, handle them all. 206 while (!Worklist.empty()) { 207#ifndef XDEBUG 208 if (EnableExpensiveChecks) 209#endif 210 PerformExpensiveChecks(); 211 212 SDNode *N = Worklist.back(); 213 Worklist.pop_back(); 214 assert(N->getNodeId() == ReadyToProcess && 215 "Node should be ready if on worklist!"); 216 217 if (IgnoreNodeResults(N)) 218 goto ScanOperands; 219 220 // Scan the values produced by the node, checking to see if any result 221 // types are illegal. 222 for (unsigned i = 0, NumResults = N->getNumValues(); i < NumResults; ++i) { 223 EVT ResultVT = N->getValueType(i); 224 switch (getTypeAction(ResultVT)) { 225 default: 226 assert(false && "Unknown action!"); 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 265ScanOperands: 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 default: 279 assert(false && "Unknown action!"); 280 case TargetLowering::TypeLegal: 281 continue; 282 // The following calls must either replace all of the node's results 283 // using ReplaceValueWith, and return "false"; or update the node's 284 // operands in place, and return "true". 285 case TargetLowering::TypePromoteInteger: 286 NeedsReanalyzing = PromoteIntegerOperand(N, i); 287 Changed = true; 288 break; 289 case TargetLowering::TypeExpandInteger: 290 NeedsReanalyzing = ExpandIntegerOperand(N, i); 291 Changed = true; 292 break; 293 case TargetLowering::TypeSoftenFloat: 294 NeedsReanalyzing = SoftenFloatOperand(N, i); 295 Changed = true; 296 break; 297 case TargetLowering::TypeExpandFloat: 298 NeedsReanalyzing = ExpandFloatOperand(N, i); 299 Changed = true; 300 break; 301 case TargetLowering::TypeScalarizeVector: 302 NeedsReanalyzing = ScalarizeVectorOperand(N, i); 303 Changed = true; 304 break; 305 case TargetLowering::TypeSplitVector: 306 NeedsReanalyzing = SplitVectorOperand(N, i); 307 Changed = true; 308 break; 309 case TargetLowering::TypeWidenVector: 310 NeedsReanalyzing = WidenVectorOperand(N, i); 311 Changed = true; 312 break; 313 } 314 break; 315 } 316 317 // The sub-method updated N in place. Check to see if any operands are new, 318 // and if so, mark them. If the node needs revisiting, don't add all users 319 // to the worklist etc. 320 if (NeedsReanalyzing) { 321 assert(N->getNodeId() == ReadyToProcess && "Node ID recalculated?"); 322 N->setNodeId(NewNode); 323 // Recompute the NodeId and correct processed operands, adding the node to 324 // the worklist if ready. 325 SDNode *M = AnalyzeNewNode(N); 326 if (M == N) 327 // The node didn't morph - nothing special to do, it will be revisited. 328 continue; 329 330 // The node morphed - this is equivalent to legalizing by replacing every 331 // value of N with the corresponding value of M. So do that now. 332 assert(N->getNumValues() == M->getNumValues() && 333 "Node morphing changed the number of results!"); 334 for (unsigned i = 0, e = N->getNumValues(); i != e; ++i) 335 // Replacing the value takes care of remapping the new value. 336 ReplaceValueWith(SDValue(N, i), SDValue(M, i)); 337 assert(N->getNodeId() == NewNode && "Unexpected node state!"); 338 // The node continues to live on as part of the NewNode fungus that 339 // grows on top of the useful nodes. Nothing more needs to be done 340 // with it - move on to the next node. 341 continue; 342 } 343 344 if (i == NumOperands) { 345 DEBUG(dbgs() << "Legally typed node: "; N->dump(&DAG); dbgs() << "\n"); 346 } 347 } 348NodeDone: 349 350 // If we reach here, the node was processed, potentially creating new nodes. 351 // Mark it as processed and add its users to the worklist as appropriate. 352 assert(N->getNodeId() == ReadyToProcess && "Node ID recalculated?"); 353 N->setNodeId(Processed); 354 355 for (SDNode::use_iterator UI = N->use_begin(), E = N->use_end(); 356 UI != E; ++UI) { 357 SDNode *User = *UI; 358 int NodeId = User->getNodeId(); 359 360 // This node has two options: it can either be a new node or its Node ID 361 // may be a count of the number of operands it has that are not ready. 362 if (NodeId > 0) { 363 User->setNodeId(NodeId-1); 364 365 // If this was the last use it was waiting on, add it to the ready list. 366 if (NodeId-1 == ReadyToProcess) 367 Worklist.push_back(User); 368 continue; 369 } 370 371 // If this is an unreachable new node, then ignore it. If it ever becomes 372 // reachable by being used by a newly created node then it will be handled 373 // by AnalyzeNewNode. 374 if (NodeId == NewNode) 375 continue; 376 377 // Otherwise, this node is new: this is the first operand of it that 378 // became ready. Its new NodeId is the number of operands it has minus 1 379 // (as this node is now processed). 380 assert(NodeId == Unanalyzed && "Unknown node ID!"); 381 User->setNodeId(User->getNumOperands() - 1); 382 383 // If the node only has a single operand, it is now ready. 384 if (User->getNumOperands() == 1) 385 Worklist.push_back(User); 386 } 387 } 388 389#ifndef XDEBUG 390 if (EnableExpensiveChecks) 391#endif 392 PerformExpensiveChecks(); 393 394 // If the root changed (e.g. it was a dead load) update the root. 395 DAG.setRoot(Dummy.getValue()); 396 397 // Remove dead nodes. This is important to do for cleanliness but also before 398 // the checking loop below. Implicit folding by the DAG.getNode operators and 399 // node morphing can cause unreachable nodes to be around with their flags set 400 // to new. 401 DAG.RemoveDeadNodes(); 402 403 // In a debug build, scan all the nodes to make sure we found them all. This 404 // ensures that there are no cycles and that everything got processed. 405#ifndef NDEBUG 406 for (SelectionDAG::allnodes_iterator I = DAG.allnodes_begin(), 407 E = DAG.allnodes_end(); I != E; ++I) { 408 bool Failed = false; 409 410 // Check that all result types are legal. 411 if (!IgnoreNodeResults(I)) 412 for (unsigned i = 0, NumVals = I->getNumValues(); i < NumVals; ++i) 413 if (!isTypeLegal(I->getValueType(i))) { 414 dbgs() << "Result type " << i << " illegal!\n"; 415 Failed = true; 416 } 417 418 // Check that all operand types are legal. 419 for (unsigned i = 0, NumOps = I->getNumOperands(); i < NumOps; ++i) 420 if (!IgnoreNodeResults(I->getOperand(i).getNode()) && 421 !isTypeLegal(I->getOperand(i).getValueType())) { 422 dbgs() << "Operand type " << i << " illegal!\n"; 423 Failed = true; 424 } 425 426 if (I->getNodeId() != Processed) { 427 if (I->getNodeId() == NewNode) 428 dbgs() << "New node not analyzed?\n"; 429 else if (I->getNodeId() == Unanalyzed) 430 dbgs() << "Unanalyzed node not noticed?\n"; 431 else if (I->getNodeId() > 0) 432 dbgs() << "Operand not processed?\n"; 433 else if (I->getNodeId() == ReadyToProcess) 434 dbgs() << "Not added to worklist?\n"; 435 Failed = true; 436 } 437 438 if (Failed) { 439 I->dump(&DAG); dbgs() << "\n"; 440 llvm_unreachable(0); 441 } 442 } 443#endif 444 445 return Changed; 446} 447 448/// AnalyzeNewNode - The specified node is the root of a subtree of potentially 449/// new nodes. Correct any processed operands (this may change the node) and 450/// calculate the NodeId. If the node itself changes to a processed node, it 451/// is not remapped - the caller needs to take care of this. 452/// Returns the potentially changed node. 453SDNode *DAGTypeLegalizer::AnalyzeNewNode(SDNode *N) { 454 // If this was an existing node that is already done, we're done. 455 if (N->getNodeId() != NewNode && N->getNodeId() != Unanalyzed) 456 return N; 457 458 // Remove any stale map entries. 459 ExpungeNode(N); 460 461 // Okay, we know that this node is new. Recursively walk all of its operands 462 // to see if they are new also. The depth of this walk is bounded by the size 463 // of the new tree that was constructed (usually 2-3 nodes), so we don't worry 464 // about revisiting of nodes. 465 // 466 // As we walk the operands, keep track of the number of nodes that are 467 // processed. If non-zero, this will become the new nodeid of this node. 468 // Operands may morph when they are analyzed. If so, the node will be 469 // updated after all operands have been analyzed. Since this is rare, 470 // the code tries to minimize overhead in the non-morphing case. 471 472 SmallVector<SDValue, 8> NewOps; 473 unsigned NumProcessed = 0; 474 for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i) { 475 SDValue OrigOp = N->getOperand(i); 476 SDValue Op = OrigOp; 477 478 AnalyzeNewValue(Op); // Op may morph. 479 480 if (Op.getNode()->getNodeId() == Processed) 481 ++NumProcessed; 482 483 if (!NewOps.empty()) { 484 // Some previous operand changed. Add this one to the list. 485 NewOps.push_back(Op); 486 } else if (Op != OrigOp) { 487 // This is the first operand to change - add all operands so far. 488 NewOps.append(N->op_begin(), N->op_begin() + i); 489 NewOps.push_back(Op); 490 } 491 } 492 493 // Some operands changed - update the node. 494 if (!NewOps.empty()) { 495 SDNode *M = DAG.UpdateNodeOperands(N, &NewOps[0], NewOps.size()); 496 if (M != N) { 497 // The node morphed into a different node. Normally for this to happen 498 // the original node would have to be marked NewNode. However this can 499 // in theory momentarily not be the case while ReplaceValueWith is doing 500 // its stuff. Mark the original node NewNode to help sanity checking. 501 N->setNodeId(NewNode); 502 if (M->getNodeId() != NewNode && M->getNodeId() != Unanalyzed) 503 // It morphed into a previously analyzed node - nothing more to do. 504 return M; 505 506 // It morphed into a different new node. Do the equivalent of passing 507 // it to AnalyzeNewNode: expunge it and calculate the NodeId. No need 508 // to remap the operands, since they are the same as the operands we 509 // remapped above. 510 N = M; 511 ExpungeNode(N); 512 } 513 } 514 515 // Calculate the NodeId. 516 N->setNodeId(N->getNumOperands() - NumProcessed); 517 if (N->getNodeId() == ReadyToProcess) 518 Worklist.push_back(N); 519 520 return N; 521} 522 523/// AnalyzeNewValue - Call AnalyzeNewNode, updating the node in Val if needed. 524/// If the node changes to a processed node, then remap it. 525void DAGTypeLegalizer::AnalyzeNewValue(SDValue &Val) { 526 Val.setNode(AnalyzeNewNode(Val.getNode())); 527 if (Val.getNode()->getNodeId() == Processed) 528 // We were passed a processed node, or it morphed into one - remap it. 529 RemapValue(Val); 530} 531 532/// ExpungeNode - If N has a bogus mapping in ReplacedValues, eliminate it. 533/// This can occur when a node is deleted then reallocated as a new node - 534/// the mapping in ReplacedValues applies to the deleted node, not the new 535/// one. 536/// The only map that can have a deleted node as a source is ReplacedValues. 537/// Other maps can have deleted nodes as targets, but since their looked-up 538/// values are always immediately remapped using RemapValue, resulting in a 539/// not-deleted node, this is harmless as long as ReplacedValues/RemapValue 540/// always performs correct mappings. In order to keep the mapping correct, 541/// ExpungeNode should be called on any new nodes *before* adding them as 542/// either source or target to ReplacedValues (which typically means calling 543/// Expunge when a new node is first seen, since it may no longer be marked 544/// NewNode by the time it is added to ReplacedValues). 545void DAGTypeLegalizer::ExpungeNode(SDNode *N) { 546 if (N->getNodeId() != NewNode) 547 return; 548 549 // If N is not remapped by ReplacedValues then there is nothing to do. 550 unsigned i, e; 551 for (i = 0, e = N->getNumValues(); i != e; ++i) 552 if (ReplacedValues.find(SDValue(N, i)) != ReplacedValues.end()) 553 break; 554 555 if (i == e) 556 return; 557 558 // Remove N from all maps - this is expensive but rare. 559 560 for (DenseMap<SDValue, SDValue>::iterator I = PromotedIntegers.begin(), 561 E = PromotedIntegers.end(); I != E; ++I) { 562 assert(I->first.getNode() != N); 563 RemapValue(I->second); 564 } 565 566 for (DenseMap<SDValue, SDValue>::iterator I = SoftenedFloats.begin(), 567 E = SoftenedFloats.end(); I != E; ++I) { 568 assert(I->first.getNode() != N); 569 RemapValue(I->second); 570 } 571 572 for (DenseMap<SDValue, SDValue>::iterator I = ScalarizedVectors.begin(), 573 E = ScalarizedVectors.end(); I != E; ++I) { 574 assert(I->first.getNode() != N); 575 RemapValue(I->second); 576 } 577 578 for (DenseMap<SDValue, SDValue>::iterator I = WidenedVectors.begin(), 579 E = WidenedVectors.end(); I != E; ++I) { 580 assert(I->first.getNode() != N); 581 RemapValue(I->second); 582 } 583 584 for (DenseMap<SDValue, std::pair<SDValue, SDValue> >::iterator 585 I = ExpandedIntegers.begin(), E = ExpandedIntegers.end(); I != E; ++I){ 586 assert(I->first.getNode() != N); 587 RemapValue(I->second.first); 588 RemapValue(I->second.second); 589 } 590 591 for (DenseMap<SDValue, std::pair<SDValue, SDValue> >::iterator 592 I = ExpandedFloats.begin(), E = ExpandedFloats.end(); I != E; ++I) { 593 assert(I->first.getNode() != N); 594 RemapValue(I->second.first); 595 RemapValue(I->second.second); 596 } 597 598 for (DenseMap<SDValue, std::pair<SDValue, SDValue> >::iterator 599 I = SplitVectors.begin(), E = SplitVectors.end(); I != E; ++I) { 600 assert(I->first.getNode() != N); 601 RemapValue(I->second.first); 602 RemapValue(I->second.second); 603 } 604 605 for (DenseMap<SDValue, SDValue>::iterator I = ReplacedValues.begin(), 606 E = ReplacedValues.end(); I != E; ++I) 607 RemapValue(I->second); 608 609 for (unsigned i = 0, e = N->getNumValues(); i != e; ++i) 610 ReplacedValues.erase(SDValue(N, i)); 611} 612 613/// RemapValue - If the specified value was already legalized to another value, 614/// replace it by that value. 615void DAGTypeLegalizer::RemapValue(SDValue &N) { 616 DenseMap<SDValue, SDValue>::iterator I = ReplacedValues.find(N); 617 if (I != ReplacedValues.end()) { 618 // Use path compression to speed up future lookups if values get multiply 619 // replaced with other values. 620 RemapValue(I->second); 621 N = I->second; 622 assert(N.getNode()->getNodeId() != NewNode && "Mapped to new node!"); 623 } 624} 625 626namespace { 627 /// NodeUpdateListener - This class is a DAGUpdateListener that listens for 628 /// updates to nodes and recomputes their ready state. 629 class NodeUpdateListener : public SelectionDAG::DAGUpdateListener { 630 DAGTypeLegalizer &DTL; 631 SmallSetVector<SDNode*, 16> &NodesToAnalyze; 632 public: 633 explicit NodeUpdateListener(DAGTypeLegalizer &dtl, 634 SmallSetVector<SDNode*, 16> &nta) 635 : DTL(dtl), NodesToAnalyze(nta) {} 636 637 virtual void NodeDeleted(SDNode *N, SDNode *E) { 638 assert(N->getNodeId() != DAGTypeLegalizer::ReadyToProcess && 639 N->getNodeId() != DAGTypeLegalizer::Processed && 640 "Invalid node ID for RAUW deletion!"); 641 // It is possible, though rare, for the deleted node N to occur as a 642 // target in a map, so note the replacement N -> E in ReplacedValues. 643 assert(E && "Node not replaced?"); 644 DTL.NoteDeletion(N, E); 645 646 // In theory the deleted node could also have been scheduled for analysis. 647 // So remove it from the set of nodes which will be analyzed. 648 NodesToAnalyze.remove(N); 649 650 // In general nothing needs to be done for E, since it didn't change but 651 // only gained new uses. However N -> E was just added to ReplacedValues, 652 // and the result of a ReplacedValues mapping is not allowed to be marked 653 // NewNode. So if E is marked NewNode, then it needs to be analyzed. 654 if (E->getNodeId() == DAGTypeLegalizer::NewNode) 655 NodesToAnalyze.insert(E); 656 } 657 658 virtual void NodeUpdated(SDNode *N) { 659 // Node updates can mean pretty much anything. It is possible that an 660 // operand was set to something already processed (f.e.) in which case 661 // this node could become ready. Recompute its flags. 662 assert(N->getNodeId() != DAGTypeLegalizer::ReadyToProcess && 663 N->getNodeId() != DAGTypeLegalizer::Processed && 664 "Invalid node ID for RAUW deletion!"); 665 N->setNodeId(DAGTypeLegalizer::NewNode); 666 NodesToAnalyze.insert(N); 667 } 668 }; 669} 670 671 672/// ReplaceValueWith - The specified value was legalized to the specified other 673/// value. Update the DAG and NodeIds replacing any uses of From to use To 674/// instead. 675void DAGTypeLegalizer::ReplaceValueWith(SDValue From, SDValue To) { 676 assert(From.getNode() != To.getNode() && "Potential legalization loop!"); 677 678 // If expansion produced new nodes, make sure they are properly marked. 679 ExpungeNode(From.getNode()); 680 AnalyzeNewValue(To); // Expunges To. 681 682 // Anything that used the old node should now use the new one. Note that this 683 // can potentially cause recursive merging. 684 SmallSetVector<SDNode*, 16> NodesToAnalyze; 685 NodeUpdateListener NUL(*this, NodesToAnalyze); 686 do { 687 DAG.ReplaceAllUsesOfValueWith(From, To, &NUL); 688 689 // The old node may still be present in a map like ExpandedIntegers or 690 // PromotedIntegers. Inform maps about the replacement. 691 ReplacedValues[From] = To; 692 693 // Process the list of nodes that need to be reanalyzed. 694 while (!NodesToAnalyze.empty()) { 695 SDNode *N = NodesToAnalyze.back(); 696 NodesToAnalyze.pop_back(); 697 if (N->getNodeId() != DAGTypeLegalizer::NewNode) 698 // The node was analyzed while reanalyzing an earlier node - it is safe 699 // to skip. Note that this is not a morphing node - otherwise it would 700 // still be marked NewNode. 701 continue; 702 703 // Analyze the node's operands and recalculate the node ID. 704 SDNode *M = AnalyzeNewNode(N); 705 if (M != N) { 706 // The node morphed into a different node. Make everyone use the new 707 // node instead. 708 assert(M->getNodeId() != NewNode && "Analysis resulted in NewNode!"); 709 assert(N->getNumValues() == M->getNumValues() && 710 "Node morphing changed the number of results!"); 711 for (unsigned i = 0, e = N->getNumValues(); i != e; ++i) { 712 SDValue OldVal(N, i); 713 SDValue NewVal(M, i); 714 if (M->getNodeId() == Processed) 715 RemapValue(NewVal); 716 DAG.ReplaceAllUsesOfValueWith(OldVal, NewVal, &NUL); 717 // OldVal may be a target of the ReplacedValues map which was marked 718 // NewNode to force reanalysis because it was updated. Ensure that 719 // anything that ReplacedValues mapped to OldVal will now be mapped 720 // all the way to NewVal. 721 ReplacedValues[OldVal] = NewVal; 722 } 723 // The original node continues to exist in the DAG, marked NewNode. 724 } 725 } 726 // When recursively update nodes with new nodes, it is possible to have 727 // new uses of From due to CSE. If this happens, replace the new uses of 728 // From with To. 729 } while (!From.use_empty()); 730} 731 732void DAGTypeLegalizer::SetPromotedInteger(SDValue Op, SDValue Result) { 733 assert(Result.getValueType() == 734 TLI.getTypeToTransformTo(*DAG.getContext(), Op.getValueType()) && 735 "Invalid type for promoted integer"); 736 AnalyzeNewValue(Result); 737 738 SDValue &OpEntry = PromotedIntegers[Op]; 739 assert(OpEntry.getNode() == 0 && "Node is already promoted!"); 740 OpEntry = Result; 741} 742 743void DAGTypeLegalizer::SetSoftenedFloat(SDValue Op, SDValue Result) { 744 assert(Result.getValueType() == 745 TLI.getTypeToTransformTo(*DAG.getContext(), Op.getValueType()) && 746 "Invalid type for softened float"); 747 AnalyzeNewValue(Result); 748 749 SDValue &OpEntry = SoftenedFloats[Op]; 750 assert(OpEntry.getNode() == 0 && "Node is already converted to integer!"); 751 OpEntry = Result; 752} 753 754void DAGTypeLegalizer::SetScalarizedVector(SDValue Op, SDValue Result) { 755 assert(Result.getValueType() == Op.getValueType().getVectorElementType() && 756 "Invalid type for scalarized vector"); 757 AnalyzeNewValue(Result); 758 759 SDValue &OpEntry = ScalarizedVectors[Op]; 760 assert(OpEntry.getNode() == 0 && "Node is already scalarized!"); 761 OpEntry = Result; 762} 763 764void DAGTypeLegalizer::GetExpandedInteger(SDValue Op, SDValue &Lo, 765 SDValue &Hi) { 766 std::pair<SDValue, SDValue> &Entry = ExpandedIntegers[Op]; 767 RemapValue(Entry.first); 768 RemapValue(Entry.second); 769 assert(Entry.first.getNode() && "Operand isn't expanded"); 770 Lo = Entry.first; 771 Hi = Entry.second; 772} 773 774void DAGTypeLegalizer::SetExpandedInteger(SDValue Op, SDValue Lo, 775 SDValue Hi) { 776 assert(Lo.getValueType() == 777 TLI.getTypeToTransformTo(*DAG.getContext(), Op.getValueType()) && 778 Hi.getValueType() == Lo.getValueType() && 779 "Invalid type for expanded integer"); 780 // Lo/Hi may have been newly allocated, if so, add nodeid's as relevant. 781 AnalyzeNewValue(Lo); 782 AnalyzeNewValue(Hi); 783 784 // Remember that this is the result of the node. 785 std::pair<SDValue, SDValue> &Entry = ExpandedIntegers[Op]; 786 assert(Entry.first.getNode() == 0 && "Node already expanded"); 787 Entry.first = Lo; 788 Entry.second = Hi; 789} 790 791void DAGTypeLegalizer::GetExpandedFloat(SDValue Op, SDValue &Lo, 792 SDValue &Hi) { 793 std::pair<SDValue, SDValue> &Entry = ExpandedFloats[Op]; 794 RemapValue(Entry.first); 795 RemapValue(Entry.second); 796 assert(Entry.first.getNode() && "Operand isn't expanded"); 797 Lo = Entry.first; 798 Hi = Entry.second; 799} 800 801void DAGTypeLegalizer::SetExpandedFloat(SDValue Op, SDValue Lo, 802 SDValue Hi) { 803 assert(Lo.getValueType() == 804 TLI.getTypeToTransformTo(*DAG.getContext(), Op.getValueType()) && 805 Hi.getValueType() == Lo.getValueType() && 806 "Invalid type for expanded float"); 807 // Lo/Hi may have been newly allocated, if so, add nodeid's as relevant. 808 AnalyzeNewValue(Lo); 809 AnalyzeNewValue(Hi); 810 811 // Remember that this is the result of the node. 812 std::pair<SDValue, SDValue> &Entry = ExpandedFloats[Op]; 813 assert(Entry.first.getNode() == 0 && "Node already expanded"); 814 Entry.first = Lo; 815 Entry.second = Hi; 816} 817 818void DAGTypeLegalizer::GetSplitVector(SDValue Op, SDValue &Lo, 819 SDValue &Hi) { 820 std::pair<SDValue, SDValue> &Entry = SplitVectors[Op]; 821 RemapValue(Entry.first); 822 RemapValue(Entry.second); 823 assert(Entry.first.getNode() && "Operand isn't split"); 824 Lo = Entry.first; 825 Hi = Entry.second; 826} 827 828void DAGTypeLegalizer::SetSplitVector(SDValue Op, SDValue Lo, 829 SDValue Hi) { 830 assert(Lo.getValueType().getVectorElementType() == 831 Op.getValueType().getVectorElementType() && 832 2*Lo.getValueType().getVectorNumElements() == 833 Op.getValueType().getVectorNumElements() && 834 Hi.getValueType() == Lo.getValueType() && 835 "Invalid type for split vector"); 836 // Lo/Hi may have been newly allocated, if so, add nodeid's as relevant. 837 AnalyzeNewValue(Lo); 838 AnalyzeNewValue(Hi); 839 840 // Remember that this is the result of the node. 841 std::pair<SDValue, SDValue> &Entry = SplitVectors[Op]; 842 assert(Entry.first.getNode() == 0 && "Node already split"); 843 Entry.first = Lo; 844 Entry.second = Hi; 845} 846 847void DAGTypeLegalizer::SetWidenedVector(SDValue Op, SDValue Result) { 848 assert(Result.getValueType() == 849 TLI.getTypeToTransformTo(*DAG.getContext(), Op.getValueType()) && 850 "Invalid type for widened vector"); 851 AnalyzeNewValue(Result); 852 853 SDValue &OpEntry = WidenedVectors[Op]; 854 assert(OpEntry.getNode() == 0 && "Node already widened!"); 855 OpEntry = Result; 856} 857 858 859//===----------------------------------------------------------------------===// 860// Utilities. 861//===----------------------------------------------------------------------===// 862 863/// BitConvertToInteger - Convert to an integer of the same size. 864SDValue DAGTypeLegalizer::BitConvertToInteger(SDValue Op) { 865 unsigned BitWidth = Op.getValueType().getSizeInBits(); 866 return DAG.getNode(ISD::BITCAST, Op.getDebugLoc(), 867 EVT::getIntegerVT(*DAG.getContext(), BitWidth), Op); 868} 869 870/// BitConvertVectorToIntegerVector - Convert to a vector of integers of the 871/// same size. 872SDValue DAGTypeLegalizer::BitConvertVectorToIntegerVector(SDValue Op) { 873 assert(Op.getValueType().isVector() && "Only applies to vectors!"); 874 unsigned EltWidth = Op.getValueType().getVectorElementType().getSizeInBits(); 875 EVT EltNVT = EVT::getIntegerVT(*DAG.getContext(), EltWidth); 876 unsigned NumElts = Op.getValueType().getVectorNumElements(); 877 return DAG.getNode(ISD::BITCAST, Op.getDebugLoc(), 878 EVT::getVectorVT(*DAG.getContext(), EltNVT, NumElts), Op); 879} 880 881SDValue DAGTypeLegalizer::CreateStackStoreLoad(SDValue Op, 882 EVT DestVT) { 883 DebugLoc dl = Op.getDebugLoc(); 884 // Create the stack frame object. Make sure it is aligned for both 885 // the source and destination types. 886 SDValue StackPtr = DAG.CreateStackTemporary(Op.getValueType(), DestVT); 887 // Emit a store to the stack slot. 888 SDValue Store = DAG.getStore(DAG.getEntryNode(), dl, Op, StackPtr, 889 MachinePointerInfo(), false, false, 0); 890 // Result is a load from the stack slot. 891 return DAG.getLoad(DestVT, dl, Store, StackPtr, MachinePointerInfo(), 892 false, false, 0); 893} 894 895/// CustomLowerNode - Replace the node's results with custom code provided 896/// by the target and return "true", or do nothing and return "false". 897/// The last parameter is FALSE if we are dealing with a node with legal 898/// result types and illegal operand. The second parameter denotes the type of 899/// illegal OperandNo in that case. 900/// The last parameter being TRUE means we are dealing with a 901/// node with illegal result types. The second parameter denotes the type of 902/// illegal ResNo in that case. 903bool DAGTypeLegalizer::CustomLowerNode(SDNode *N, EVT VT, bool LegalizeResult) { 904 // See if the target wants to custom lower this node. 905 if (TLI.getOperationAction(N->getOpcode(), VT) != TargetLowering::Custom) 906 return false; 907 908 SmallVector<SDValue, 8> Results; 909 if (LegalizeResult) 910 TLI.ReplaceNodeResults(N, Results, DAG); 911 else 912 TLI.LowerOperationWrapper(N, Results, DAG); 913 914 if (Results.empty()) 915 // The target didn't want to custom lower it after all. 916 return false; 917 918 // Make everything that once used N's values now use those in Results instead. 919 assert(Results.size() == N->getNumValues() && 920 "Custom lowering returned the wrong number of results!"); 921 for (unsigned i = 0, e = Results.size(); i != e; ++i) 922 ReplaceValueWith(SDValue(N, i), Results[i]); 923 return true; 924} 925 926 927/// CustomWidenLowerNode - Widen the node's results with custom code provided 928/// by the target and return "true", or do nothing and return "false". 929bool DAGTypeLegalizer::CustomWidenLowerNode(SDNode *N, EVT VT) { 930 // See if the target wants to custom lower this node. 931 if (TLI.getOperationAction(N->getOpcode(), VT) != TargetLowering::Custom) 932 return false; 933 934 SmallVector<SDValue, 8> Results; 935 TLI.ReplaceNodeResults(N, Results, DAG); 936 937 if (Results.empty()) 938 // The target didn't want to custom widen lower its result after all. 939 return false; 940 941 // Update the widening map. 942 assert(Results.size() == N->getNumValues() && 943 "Custom lowering returned the wrong number of results!"); 944 for (unsigned i = 0, e = Results.size(); i != e; ++i) 945 SetWidenedVector(SDValue(N, i), Results[i]); 946 return true; 947} 948 949/// GetSplitDestVTs - Compute the VTs needed for the low/hi parts of a type 950/// which is split into two not necessarily identical pieces. 951void DAGTypeLegalizer::GetSplitDestVTs(EVT InVT, EVT &LoVT, EVT &HiVT) { 952 // Currently all types are split in half. 953 if (!InVT.isVector()) { 954 LoVT = HiVT = TLI.getTypeToTransformTo(*DAG.getContext(), InVT); 955 } else { 956 unsigned NumElements = InVT.getVectorNumElements(); 957 assert(!(NumElements & 1) && "Splitting vector, but not in half!"); 958 LoVT = HiVT = EVT::getVectorVT(*DAG.getContext(), 959 InVT.getVectorElementType(), NumElements/2); 960 } 961} 962 963/// GetPairElements - Use ISD::EXTRACT_ELEMENT nodes to extract the low and 964/// high parts of the given value. 965void DAGTypeLegalizer::GetPairElements(SDValue Pair, 966 SDValue &Lo, SDValue &Hi) { 967 DebugLoc dl = Pair.getDebugLoc(); 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 975SDValue DAGTypeLegalizer::GetVectorElementPointer(SDValue VecPtr, EVT EltVT, 976 SDValue Index) { 977 DebugLoc dl = Index.getDebugLoc(); 978 // Make sure the index type is big enough to compute in. 979 if (Index.getValueType().bitsGT(TLI.getPointerTy())) 980 Index = DAG.getNode(ISD::TRUNCATE, dl, TLI.getPointerTy(), Index); 981 else 982 Index = DAG.getNode(ISD::ZERO_EXTEND, dl, TLI.getPointerTy(), Index); 983 984 // Calculate the element offset and add it to the pointer. 985 unsigned EltSize = EltVT.getSizeInBits() / 8; // FIXME: should be ABI size. 986 987 Index = DAG.getNode(ISD::MUL, dl, Index.getValueType(), Index, 988 DAG.getConstant(EltSize, Index.getValueType())); 989 return DAG.getNode(ISD::ADD, dl, Index.getValueType(), Index, VecPtr); 990} 991 992/// JoinIntegers - Build an integer with low bits Lo and high bits Hi. 993SDValue DAGTypeLegalizer::JoinIntegers(SDValue Lo, SDValue Hi) { 994 // Arbitrarily use dlHi for result DebugLoc 995 DebugLoc dlHi = Hi.getDebugLoc(); 996 DebugLoc dlLo = Lo.getDebugLoc(); 997 EVT LVT = Lo.getValueType(); 998 EVT HVT = Hi.getValueType(); 999 EVT NVT = EVT::getIntegerVT(*DAG.getContext(), 1000 LVT.getSizeInBits() + HVT.getSizeInBits()); 1001 1002 Lo = DAG.getNode(ISD::ZERO_EXTEND, dlLo, NVT, Lo); 1003 Hi = DAG.getNode(ISD::ANY_EXTEND, dlHi, NVT, Hi); 1004 Hi = DAG.getNode(ISD::SHL, dlHi, NVT, Hi, 1005 DAG.getConstant(LVT.getSizeInBits(), TLI.getPointerTy())); 1006 return DAG.getNode(ISD::OR, dlHi, NVT, Lo, Hi); 1007} 1008 1009/// LibCallify - Convert the node into a libcall with the same prototype. 1010SDValue DAGTypeLegalizer::LibCallify(RTLIB::Libcall LC, SDNode *N, 1011 bool isSigned) { 1012 unsigned NumOps = N->getNumOperands(); 1013 DebugLoc dl = N->getDebugLoc(); 1014 if (NumOps == 0) { 1015 return MakeLibCall(LC, N->getValueType(0), 0, 0, isSigned, dl); 1016 } else if (NumOps == 1) { 1017 SDValue Op = N->getOperand(0); 1018 return MakeLibCall(LC, N->getValueType(0), &Op, 1, isSigned, dl); 1019 } else if (NumOps == 2) { 1020 SDValue Ops[2] = { N->getOperand(0), N->getOperand(1) }; 1021 return MakeLibCall(LC, N->getValueType(0), Ops, 2, isSigned, dl); 1022 } 1023 SmallVector<SDValue, 8> Ops(NumOps); 1024 for (unsigned i = 0; i < NumOps; ++i) 1025 Ops[i] = N->getOperand(i); 1026 1027 return MakeLibCall(LC, N->getValueType(0), &Ops[0], NumOps, isSigned, dl); 1028} 1029 1030/// MakeLibCall - Generate a libcall taking the given operands as arguments and 1031/// returning a result of type RetVT. 1032SDValue DAGTypeLegalizer::MakeLibCall(RTLIB::Libcall LC, EVT RetVT, 1033 const SDValue *Ops, unsigned NumOps, 1034 bool isSigned, DebugLoc dl) { 1035 TargetLowering::ArgListTy Args; 1036 Args.reserve(NumOps); 1037 1038 TargetLowering::ArgListEntry Entry; 1039 for (unsigned i = 0; i != NumOps; ++i) { 1040 Entry.Node = Ops[i]; 1041 Entry.Ty = Entry.Node.getValueType().getTypeForEVT(*DAG.getContext()); 1042 Entry.isSExt = isSigned; 1043 Entry.isZExt = !isSigned; 1044 Args.push_back(Entry); 1045 } 1046 SDValue Callee = DAG.getExternalSymbol(TLI.getLibcallName(LC), 1047 TLI.getPointerTy()); 1048 1049 const Type *RetTy = RetVT.getTypeForEVT(*DAG.getContext()); 1050 std::pair<SDValue,SDValue> CallInfo = 1051 TLI.LowerCallTo(DAG.getEntryNode(), RetTy, isSigned, !isSigned, false, 1052 false, 0, TLI.getLibcallCallingConv(LC), false, 1053 /*isReturnValueUsed=*/true, 1054 Callee, Args, DAG, dl); 1055 return CallInfo.first; 1056} 1057 1058// ExpandChainLibCall - Expand a node into a call to a libcall. Similar to 1059// ExpandLibCall except that the first operand is the in-chain. 1060std::pair<SDValue, SDValue> 1061DAGTypeLegalizer::ExpandChainLibCall(RTLIB::Libcall LC, 1062 SDNode *Node, 1063 bool isSigned) { 1064 SDValue InChain = Node->getOperand(0); 1065 1066 TargetLowering::ArgListTy Args; 1067 TargetLowering::ArgListEntry Entry; 1068 for (unsigned i = 1, e = Node->getNumOperands(); i != e; ++i) { 1069 EVT ArgVT = Node->getOperand(i).getValueType(); 1070 const Type *ArgTy = ArgVT.getTypeForEVT(*DAG.getContext()); 1071 Entry.Node = Node->getOperand(i); 1072 Entry.Ty = ArgTy; 1073 Entry.isSExt = isSigned; 1074 Entry.isZExt = !isSigned; 1075 Args.push_back(Entry); 1076 } 1077 SDValue Callee = DAG.getExternalSymbol(TLI.getLibcallName(LC), 1078 TLI.getPointerTy()); 1079 1080 // Splice the libcall in wherever FindInputOutputChains tells us to. 1081 const Type *RetTy = Node->getValueType(0).getTypeForEVT(*DAG.getContext()); 1082 std::pair<SDValue, SDValue> CallInfo = 1083 TLI.LowerCallTo(InChain, RetTy, isSigned, !isSigned, false, false, 1084 0, TLI.getLibcallCallingConv(LC), /*isTailCall=*/false, 1085 /*isReturnValueUsed=*/true, 1086 Callee, Args, DAG, Node->getDebugLoc()); 1087 1088 return CallInfo; 1089} 1090 1091/// PromoteTargetBoolean - Promote the given target boolean to a target boolean 1092/// of the given type. A target boolean is an integer value, not necessarily of 1093/// type i1, the bits of which conform to getBooleanContents. 1094SDValue DAGTypeLegalizer::PromoteTargetBoolean(SDValue Bool, EVT VT) { 1095 DebugLoc dl = Bool.getDebugLoc(); 1096 ISD::NodeType ExtendCode; 1097 switch (TLI.getBooleanContents()) { 1098 default: 1099 assert(false && "Unknown BooleanContent!"); 1100 case TargetLowering::UndefinedBooleanContent: 1101 // Extend to VT by adding rubbish bits. 1102 ExtendCode = ISD::ANY_EXTEND; 1103 break; 1104 case TargetLowering::ZeroOrOneBooleanContent: 1105 // Extend to VT by adding zero bits. 1106 ExtendCode = ISD::ZERO_EXTEND; 1107 break; 1108 case TargetLowering::ZeroOrNegativeOneBooleanContent: { 1109 // Extend to VT by copying the sign bit. 1110 ExtendCode = ISD::SIGN_EXTEND; 1111 break; 1112 } 1113 } 1114 return DAG.getNode(ExtendCode, dl, VT, Bool); 1115} 1116 1117/// SplitInteger - Return the lower LoVT bits of Op in Lo and the upper HiVT 1118/// bits in Hi. 1119void DAGTypeLegalizer::SplitInteger(SDValue Op, 1120 EVT LoVT, EVT HiVT, 1121 SDValue &Lo, SDValue &Hi) { 1122 DebugLoc dl = Op.getDebugLoc(); 1123 assert(LoVT.getSizeInBits() + HiVT.getSizeInBits() == 1124 Op.getValueType().getSizeInBits() && "Invalid integer splitting!"); 1125 Lo = DAG.getNode(ISD::TRUNCATE, dl, LoVT, Op); 1126 Hi = DAG.getNode(ISD::SRL, dl, Op.getValueType(), Op, 1127 DAG.getConstant(LoVT.getSizeInBits(), TLI.getPointerTy())); 1128 Hi = DAG.getNode(ISD::TRUNCATE, dl, HiVT, Hi); 1129} 1130 1131/// SplitInteger - Return the lower and upper halves of Op's bits in a value 1132/// type half the size of Op's. 1133void DAGTypeLegalizer::SplitInteger(SDValue Op, 1134 SDValue &Lo, SDValue &Hi) { 1135 EVT HalfVT = EVT::getIntegerVT(*DAG.getContext(), 1136 Op.getValueType().getSizeInBits()/2); 1137 SplitInteger(Op, HalfVT, HalfVT, Lo, Hi); 1138} 1139 1140 1141//===----------------------------------------------------------------------===// 1142// Entry Point 1143//===----------------------------------------------------------------------===// 1144 1145/// LegalizeTypes - This transforms the SelectionDAG into a SelectionDAG that 1146/// only uses types natively supported by the target. Returns "true" if it made 1147/// any changes. 1148/// 1149/// Note that this is an involved process that may invalidate pointers into 1150/// the graph. 1151bool SelectionDAG::LegalizeTypes() { 1152 return DAGTypeLegalizer(*this).run(); 1153} 1154