LegalizeTypes.cpp revision 26342923118b8df5e99bf6acbac36d9af9255810
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/ADT/SmallPtrSet.h" 19#include "llvm/Support/CommandLine.h" 20#include "llvm/Target/TargetData.h" 21using namespace llvm; 22 23static cl::opt<bool> 24EnableExpensiveChecks("enable-legalize-types-checking", cl::Hidden); 25 26/// PerformExpensiveChecks - Do extensive, expensive, sanity checking. 27void DAGTypeLegalizer::PerformExpensiveChecks() { 28 // If a node is not processed, then none of its values should be mapped by any 29 // of PromotedIntegers, ExpandedIntegers, ..., ReplacedValues. 30 31 // If a node is processed, then each value with an illegal type must be mapped 32 // by exactly one of PromotedIntegers, ExpandedIntegers, ..., ReplacedValues. 33 // Values with a legal type may be mapped by ReplacedValues, but not by any of 34 // the other maps. 35 36 // Note that these invariants may not hold momentarily when processing a node: 37 // the node being processed may be put in a map before being marked Processed. 38 39 // Note that it is possible to have nodes marked NewNode in the DAG. This can 40 // occur in two ways. Firstly, a node may be created during legalization but 41 // never passed to the legalization core. This is usually due to the implicit 42 // folding that occurs when using the DAG.getNode operators. Secondly, a new 43 // node may be passed to the legalization core, but when analyzed may morph 44 // into a different node, leaving the original node as a NewNode in the DAG. 45 // A node may morph if one of its operands changes during analysis. Whether 46 // it actually morphs or not depends on whether, after updating its operands, 47 // it is equivalent to an existing node: if so, it morphs into that existing 48 // node (CSE). An operand can change during analysis if the operand is a new 49 // node that morphs, or it is a processed value that was mapped to some other 50 // value (as recorded in ReplacedValues) in which case the operand is turned 51 // into that other value. If a node morphs then the node it morphed into will 52 // be used instead of it for legalization, however the original node continues 53 // to live on in the DAG. 54 // The conclusion is that though there may be nodes marked NewNode in the DAG, 55 // all uses of such nodes are also marked NewNode: the result is a fungus of 56 // NewNodes growing on top of the useful nodes, and perhaps using them, but 57 // not used by them. 58 59 // If a value is mapped by ReplacedValues, then it must have no uses, except 60 // by nodes marked NewNode (see above). 61 62 // The final node obtained by mapping by ReplacedValues is not marked NewNode. 63 // Note that ReplacedValues should be applied iteratively. 64 65 // Note that the ReplacedValues map may also map deleted nodes. By iterating 66 // over the DAG we only consider non-deleted nodes. 67 SmallVector<SDNode*, 16> NewNodes; 68 for (SelectionDAG::allnodes_iterator I = DAG.allnodes_begin(), 69 E = DAG.allnodes_end(); I != E; ++I) { 70 // Remember nodes marked NewNode - they are subject to extra checking below. 71 if (I->getNodeId() == NewNode) 72 NewNodes.push_back(I); 73 74 for (unsigned i = 0, e = I->getNumValues(); i != e; ++i) { 75 SDValue Res(I, i); 76 bool Failed = false; 77 78 unsigned Mapped = 0; 79 if (ReplacedValues.find(Res) != ReplacedValues.end()) { 80 Mapped |= 1; 81 // Check that remapped values are only used by nodes marked NewNode. 82 for (SDNode::use_iterator UI = I->use_begin(), UE = I->use_end(); 83 UI != UE; ++UI) 84 if (UI.getUse().getSDValue().getResNo() == i) 85 assert(UI->getNodeId() == NewNode && 86 "Remapped value has non-trivial use!"); 87 88 // Check that the final result of applying ReplacedValues is not 89 // marked NewNode. 90 SDValue NewVal = ReplacedValues[Res]; 91 DenseMap<SDValue, SDValue>::iterator I = ReplacedValues.find(NewVal); 92 while (I != ReplacedValues.end()) { 93 NewVal = I->second; 94 I = ReplacedValues.find(NewVal); 95 } 96 assert(NewVal.getNode()->getNodeId() != NewNode && 97 "ReplacedValues maps to a new node!"); 98 } 99 if (PromotedIntegers.find(Res) != PromotedIntegers.end()) 100 Mapped |= 2; 101 if (SoftenedFloats.find(Res) != SoftenedFloats.end()) 102 Mapped |= 4; 103 if (ScalarizedVectors.find(Res) != ScalarizedVectors.end()) 104 Mapped |= 8; 105 if (ExpandedIntegers.find(Res) != ExpandedIntegers.end()) 106 Mapped |= 16; 107 if (ExpandedFloats.find(Res) != ExpandedFloats.end()) 108 Mapped |= 32; 109 if (SplitVectors.find(Res) != SplitVectors.end()) 110 Mapped |= 64; 111 if (WidenedVectors.find(Res) != WidenedVectors.end()) 112 Mapped |= 128; 113 114 if (I->getNodeId() != Processed) { 115 if (Mapped != 0) { 116 cerr << "Unprocessed value in a map!"; 117 Failed = true; 118 } 119 } else if (isTypeLegal(Res.getValueType()) || IgnoreNodeResults(I)) { 120 // FIXME: Because of PR2957, the build vector can be placed on this 121 // list but if the associated vector shuffle is split, the build vector 122 // can also be split so we allow this to go through for now. 123 if (Mapped > 1 && Res.getOpcode() != ISD::BUILD_VECTOR) { 124 cerr << "Value with legal type was transformed!"; 125 Failed = true; 126 } 127 } else { 128 if (Mapped == 0) { 129 cerr << "Processed value not in any map!"; 130 Failed = true; 131 } else if (Mapped & (Mapped - 1)) { 132 cerr << "Value in multiple maps!"; 133 Failed = true; 134 } 135 } 136 137 if (Failed) { 138 if (Mapped & 1) 139 cerr << " ReplacedValues"; 140 if (Mapped & 2) 141 cerr << " PromotedIntegers"; 142 if (Mapped & 4) 143 cerr << " SoftenedFloats"; 144 if (Mapped & 8) 145 cerr << " ScalarizedVectors"; 146 if (Mapped & 16) 147 cerr << " ExpandedIntegers"; 148 if (Mapped & 32) 149 cerr << " ExpandedFloats"; 150 if (Mapped & 64) 151 cerr << " SplitVectors"; 152 if (Mapped & 128) 153 cerr << " WidenedVectors"; 154 cerr << "\n"; 155 abort(); 156 } 157 } 158 } 159 160 // Checked that NewNodes are only used by other NewNodes. 161 for (unsigned i = 0, e = NewNodes.size(); i != e; ++i) { 162 SDNode *N = NewNodes[i]; 163 for (SDNode::use_iterator UI = N->use_begin(), UE = N->use_end(); 164 UI != UE; ++UI) 165 assert(UI->getNodeId() == NewNode && "NewNode used by non-NewNode!"); 166 } 167} 168 169/// run - This is the main entry point for the type legalizer. This does a 170/// top-down traversal of the dag, legalizing types as it goes. Returns "true" 171/// if it made any changes. 172bool DAGTypeLegalizer::run() { 173 bool Changed = false; 174 175 // Create a dummy node (which is not added to allnodes), that adds a reference 176 // to the root node, preventing it from being deleted, and tracking any 177 // changes of the root. 178 HandleSDNode Dummy(DAG.getRoot()); 179 Dummy.setNodeId(Unanalyzed); 180 181 // The root of the dag may dangle to deleted nodes until the type legalizer is 182 // done. Set it to null to avoid confusion. 183 DAG.setRoot(SDValue()); 184 185 // Walk all nodes in the graph, assigning them a NodeId of 'ReadyToProcess' 186 // (and remembering them) if they are leaves and assigning 'Unanalyzed' if 187 // non-leaves. 188 for (SelectionDAG::allnodes_iterator I = DAG.allnodes_begin(), 189 E = DAG.allnodes_end(); I != E; ++I) { 190 if (I->getNumOperands() == 0) { 191 I->setNodeId(ReadyToProcess); 192 Worklist.push_back(I); 193 } else { 194 I->setNodeId(Unanalyzed); 195 } 196 } 197 198 // Now that we have a set of nodes to process, handle them all. 199 while (!Worklist.empty()) { 200#ifndef XDEBUG 201 if (EnableExpensiveChecks) 202#endif 203 PerformExpensiveChecks(); 204 205 SDNode *N = Worklist.back(); 206 Worklist.pop_back(); 207 assert(N->getNodeId() == ReadyToProcess && 208 "Node should be ready if on worklist!"); 209 210 if (IgnoreNodeResults(N)) 211 goto ScanOperands; 212 213 // Scan the values produced by the node, checking to see if any result 214 // types are illegal. 215 for (unsigned i = 0, NumResults = N->getNumValues(); i < NumResults; ++i) { 216 MVT ResultVT = N->getValueType(i); 217 switch (getTypeAction(ResultVT)) { 218 default: 219 assert(false && "Unknown action!"); 220 case Legal: 221 break; 222 // The following calls must take care of *all* of the node's results, 223 // not just the illegal result they were passed (this includes results 224 // with a legal type). Results can be remapped using ReplaceValueWith, 225 // or their promoted/expanded/etc values registered in PromotedIntegers, 226 // ExpandedIntegers etc. 227 case PromoteInteger: 228 PromoteIntegerResult(N, i); 229 Changed = true; 230 goto NodeDone; 231 case ExpandInteger: 232 ExpandIntegerResult(N, i); 233 Changed = true; 234 goto NodeDone; 235 case SoftenFloat: 236 SoftenFloatResult(N, i); 237 Changed = true; 238 goto NodeDone; 239 case ExpandFloat: 240 ExpandFloatResult(N, i); 241 Changed = true; 242 goto NodeDone; 243 case ScalarizeVector: 244 ScalarizeVectorResult(N, i); 245 Changed = true; 246 goto NodeDone; 247 case SplitVector: 248 SplitVectorResult(N, i); 249 Changed = true; 250 goto NodeDone; 251 case WidenVector: 252 WidenVectorResult(N, i); 253 Changed = true; 254 goto NodeDone; 255 } 256 } 257 258ScanOperands: 259 // Scan the operand list for the node, handling any nodes with operands that 260 // are illegal. 261 { 262 unsigned NumOperands = N->getNumOperands(); 263 bool NeedsReanalyzing = false; 264 unsigned i; 265 for (i = 0; i != NumOperands; ++i) { 266 if (IgnoreNodeResults(N->getOperand(i).getNode())) 267 continue; 268 269 if (N->getOpcode() == ISD::VECTOR_SHUFFLE && i == 2) { 270 // The shuffle mask doesn't need to be a legal vector type. 271 // FIXME: We can remove this once we fix PR2957. 272 SetIgnoredNodeResult(N->getOperand(2).getNode()); 273 continue; 274 } 275 276 MVT OpVT = N->getOperand(i).getValueType(); 277 switch (getTypeAction(OpVT)) { 278 default: 279 assert(false && "Unknown action!"); 280 case Legal: 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 PromoteInteger: 286 NeedsReanalyzing = PromoteIntegerOperand(N, i); 287 Changed = true; 288 break; 289 case ExpandInteger: 290 NeedsReanalyzing = ExpandIntegerOperand(N, i); 291 Changed = true; 292 break; 293 case SoftenFloat: 294 NeedsReanalyzing = SoftenFloatOperand(N, i); 295 Changed = true; 296 break; 297 case ExpandFloat: 298 NeedsReanalyzing = ExpandFloatOperand(N, i); 299 Changed = true; 300 break; 301 case ScalarizeVector: 302 NeedsReanalyzing = ScalarizeVectorOperand(N, i); 303 Changed = true; 304 break; 305 case SplitVector: 306 NeedsReanalyzing = SplitVectorOperand(N, i); 307 Changed = true; 308 break; 309 case WidenVector: 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 N->setNodeId(ReadyToProcess); 333 assert(N->getNumValues() == M->getNumValues() && 334 "Node morphing changed the number of results!"); 335 for (unsigned i = 0, e = N->getNumValues(); i != e; ++i) 336 // Replacing the value takes care of remapping the new value. 337 ReplaceValueWith(SDValue(N, i), SDValue(M, i)); 338 // Fall through. 339 } 340 341 if (i == NumOperands) { 342 DEBUG(cerr << "Legally typed node: "; N->dump(&DAG); cerr << "\n"); 343 } 344 } 345NodeDone: 346 347 // If we reach here, the node was processed, potentially creating new nodes. 348 // Mark it as processed and add its users to the worklist as appropriate. 349 assert(N->getNodeId() == ReadyToProcess && "Node ID recalculated?"); 350 N->setNodeId(Processed); 351 352 for (SDNode::use_iterator UI = N->use_begin(), E = N->use_end(); 353 UI != E; ++UI) { 354 SDNode *User = *UI; 355 int NodeId = User->getNodeId(); 356 357 // This node has two options: it can either be a new node or its Node ID 358 // may be a count of the number of operands it has that are not ready. 359 if (NodeId > 0) { 360 User->setNodeId(NodeId-1); 361 362 // If this was the last use it was waiting on, add it to the ready list. 363 if (NodeId-1 == ReadyToProcess) 364 Worklist.push_back(User); 365 continue; 366 } 367 368 // If this is an unreachable new node, then ignore it. If it ever becomes 369 // reachable by being used by a newly created node then it will be handled 370 // by AnalyzeNewNode. 371 if (NodeId == NewNode) 372 continue; 373 374 // Otherwise, this node is new: this is the first operand of it that 375 // became ready. Its new NodeId is the number of operands it has minus 1 376 // (as this node is now processed). 377 assert(NodeId == Unanalyzed && "Unknown node ID!"); 378 User->setNodeId(User->getNumOperands() - 1); 379 380 // If the node only has a single operand, it is now ready. 381 if (User->getNumOperands() == 1) 382 Worklist.push_back(User); 383 } 384 } 385 386#ifndef XDEBUG 387 if (EnableExpensiveChecks) 388#endif 389 PerformExpensiveChecks(); 390 391 // If the root changed (e.g. it was a dead load) update the root. 392 DAG.setRoot(Dummy.getValue()); 393 394 // Remove dead nodes. This is important to do for cleanliness but also before 395 // the checking loop below. Implicit folding by the DAG.getNode operators and 396 // node morphing can cause unreachable nodes to be around with their flags set 397 // to new. 398 DAG.RemoveDeadNodes(); 399 400 // In a debug build, scan all the nodes to make sure we found them all. This 401 // ensures that there are no cycles and that everything got processed. 402#ifndef NDEBUG 403 for (SelectionDAG::allnodes_iterator I = DAG.allnodes_begin(), 404 E = DAG.allnodes_end(); I != E; ++I) { 405 bool Failed = false; 406 407 // Check that all result types are legal. 408 if (!IgnoreNodeResults(I)) 409 for (unsigned i = 0, NumVals = I->getNumValues(); i < NumVals; ++i) 410 if (!isTypeLegal(I->getValueType(i))) { 411 cerr << "Result type " << i << " illegal!\n"; 412 Failed = true; 413 } 414 415 // Check that all operand types are legal. 416 for (unsigned i = 0, NumOps = I->getNumOperands(); i < NumOps; ++i) 417 if (!IgnoreNodeResults(I->getOperand(i).getNode()) && 418 !isTypeLegal(I->getOperand(i).getValueType())) { 419 cerr << "Operand type " << i << " illegal!\n"; 420 Failed = true; 421 } 422 423 if (I->getNodeId() != Processed) { 424 if (I->getNodeId() == NewNode) 425 cerr << "New node not analyzed?\n"; 426 else if (I->getNodeId() == Unanalyzed) 427 cerr << "Unanalyzed node not noticed?\n"; 428 else if (I->getNodeId() > 0) 429 cerr << "Operand not processed?\n"; 430 else if (I->getNodeId() == ReadyToProcess) 431 cerr << "Not added to worklist?\n"; 432 Failed = true; 433 } 434 435 if (Failed) { 436 I->dump(&DAG); cerr << "\n"; 437 abort(); 438 } 439 } 440#endif 441 442 return Changed; 443} 444 445/// AnalyzeNewNode - The specified node is the root of a subtree of potentially 446/// new nodes. Correct any processed operands (this may change the node) and 447/// calculate the NodeId. If the node itself changes to a processed node, it 448/// is not remapped - the caller needs to take care of this. 449/// Returns the potentially changed node. 450SDNode *DAGTypeLegalizer::AnalyzeNewNode(SDNode *N) { 451 // If this was an existing node that is already done, we're done. 452 if (N->getNodeId() != NewNode && N->getNodeId() != Unanalyzed) 453 return N; 454 455 // Remove any stale map entries. 456 ExpungeNode(N); 457 458 // Okay, we know that this node is new. Recursively walk all of its operands 459 // to see if they are new also. The depth of this walk is bounded by the size 460 // of the new tree that was constructed (usually 2-3 nodes), so we don't worry 461 // about revisiting of nodes. 462 // 463 // As we walk the operands, keep track of the number of nodes that are 464 // processed. If non-zero, this will become the new nodeid of this node. 465 // Operands may morph when they are analyzed. If so, the node will be 466 // updated after all operands have been analyzed. Since this is rare, 467 // the code tries to minimize overhead in the non-morphing case. 468 469 SmallVector<SDValue, 8> NewOps; 470 unsigned NumProcessed = 0; 471 for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i) { 472 SDValue OrigOp = N->getOperand(i); 473 SDValue Op = OrigOp; 474 475 AnalyzeNewValue(Op); // Op may morph. 476 477 if (Op.getNode()->getNodeId() == Processed) 478 ++NumProcessed; 479 480 if (!NewOps.empty()) { 481 // Some previous operand changed. Add this one to the list. 482 NewOps.push_back(Op); 483 } else if (Op != OrigOp) { 484 // This is the first operand to change - add all operands so far. 485 for (unsigned j = 0; j < i; ++j) 486 NewOps.push_back(N->getOperand(j)); 487 NewOps.push_back(Op); 488 } 489 } 490 491 // Some operands changed - update the node. 492 if (!NewOps.empty()) { 493 SDNode *M = DAG.UpdateNodeOperands(SDValue(N, 0), &NewOps[0], 494 NewOps.size()).getNode(); 495 if (M != N) { 496 // The node morphed into a different node. Normally for this to happen 497 // the original node would have to be marked NewNode. However this can 498 // in theory momentarily not be the case while ReplaceValueWith is doing 499 // its stuff. Mark the original node NewNode to help sanity checking. 500 N->setNodeId(NewNode); 501 if (M->getNodeId() != NewNode && M->getNodeId() != Unanalyzed) 502 // It morphed into a previously analyzed node - nothing more to do. 503 return M; 504 505 // It morphed into a different new node. Do the equivalent of passing 506 // it to AnalyzeNewNode: expunge it and calculate the NodeId. No need 507 // to remap the operands, since they are the same as the operands we 508 // remapped above. 509 N = M; 510 ExpungeNode(N); 511 } 512 } 513 514 // Calculate the NodeId. 515 N->setNodeId(N->getNumOperands() - NumProcessed); 516 if (N->getNodeId() == ReadyToProcess) 517 Worklist.push_back(N); 518 519 return N; 520} 521 522/// AnalyzeNewValue - Call AnalyzeNewNode, updating the node in Val if needed. 523/// If the node changes to a processed node, then remap it. 524void DAGTypeLegalizer::AnalyzeNewValue(SDValue &Val) { 525 Val.setNode(AnalyzeNewNode(Val.getNode())); 526 if (Val.getNode()->getNodeId() == Processed) 527 // We were passed a processed node, or it morphed into one - remap it. 528 RemapValue(Val); 529} 530 531/// ExpungeNode - If N has a bogus mapping in ReplacedValues, eliminate it. 532/// This can occur when a node is deleted then reallocated as a new node - 533/// the mapping in ReplacedValues applies to the deleted node, not the new 534/// one. 535/// The only map that can have a deleted node as a source is ReplacedValues. 536/// Other maps can have deleted nodes as targets, but since their looked-up 537/// values are always immediately remapped using RemapValue, resulting in a 538/// not-deleted node, this is harmless as long as ReplacedValues/RemapValue 539/// always performs correct mappings. In order to keep the mapping correct, 540/// ExpungeNode should be called on any new nodes *before* adding them as 541/// either source or target to ReplacedValues (which typically means calling 542/// Expunge when a new node is first seen, since it may no longer be marked 543/// NewNode by the time it is added to ReplacedValues). 544void DAGTypeLegalizer::ExpungeNode(SDNode *N) { 545 if (N->getNodeId() != NewNode) 546 return; 547 548 // If N is not remapped by ReplacedValues then there is nothing to do. 549 unsigned i, e; 550 for (i = 0, e = N->getNumValues(); i != e; ++i) 551 if (ReplacedValues.find(SDValue(N, i)) != ReplacedValues.end()) 552 break; 553 554 if (i == e) 555 return; 556 557 // Remove N from all maps - this is expensive but rare. 558 559 for (DenseMap<SDValue, SDValue>::iterator I = PromotedIntegers.begin(), 560 E = PromotedIntegers.end(); I != E; ++I) { 561 assert(I->first.getNode() != N); 562 RemapValue(I->second); 563 } 564 565 for (DenseMap<SDValue, SDValue>::iterator I = SoftenedFloats.begin(), 566 E = SoftenedFloats.end(); I != E; ++I) { 567 assert(I->first.getNode() != N); 568 RemapValue(I->second); 569 } 570 571 for (DenseMap<SDValue, SDValue>::iterator I = ScalarizedVectors.begin(), 572 E = ScalarizedVectors.end(); I != E; ++I) { 573 assert(I->first.getNode() != N); 574 RemapValue(I->second); 575 } 576 577 for (DenseMap<SDValue, std::pair<SDValue, SDValue> >::iterator 578 I = ExpandedIntegers.begin(), E = ExpandedIntegers.end(); I != E; ++I){ 579 assert(I->first.getNode() != N); 580 RemapValue(I->second.first); 581 RemapValue(I->second.second); 582 } 583 584 for (DenseMap<SDValue, std::pair<SDValue, SDValue> >::iterator 585 I = ExpandedFloats.begin(), E = ExpandedFloats.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 = SplitVectors.begin(), E = SplitVectors.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, SDValue>::iterator I = ReplacedValues.begin(), 599 E = ReplacedValues.end(); I != E; ++I) 600 RemapValue(I->second); 601 602 for (unsigned i = 0, e = N->getNumValues(); i != e; ++i) 603 ReplacedValues.erase(SDValue(N, i)); 604} 605 606/// RemapValue - If the specified value was already legalized to another value, 607/// replace it by that value. 608void DAGTypeLegalizer::RemapValue(SDValue &N) { 609 DenseMap<SDValue, SDValue>::iterator I = ReplacedValues.find(N); 610 if (I != ReplacedValues.end()) { 611 // Use path compression to speed up future lookups if values get multiply 612 // replaced with other values. 613 RemapValue(I->second); 614 N = I->second; 615 assert(N.getNode()->getNodeId() != NewNode && "Mapped to new node!"); 616 } 617} 618 619namespace { 620 /// NodeUpdateListener - This class is a DAGUpdateListener that listens for 621 /// updates to nodes and recomputes their ready state. 622 class VISIBILITY_HIDDEN NodeUpdateListener : 623 public SelectionDAG::DAGUpdateListener { 624 DAGTypeLegalizer &DTL; 625 SmallVectorImpl<SDNode*> &NodesToAnalyze; 626 SmallPtrSet<SDNode*, 16> &NodesDeleted; 627 public: 628 explicit NodeUpdateListener(DAGTypeLegalizer &dtl, 629 SmallVectorImpl<SDNode*> &nta, 630 SmallPtrSet<SDNode*, 16> &nd) 631 : DTL(dtl), NodesToAnalyze(nta), NodesDeleted(nd) {} 632 633 virtual void NodeDeleted(SDNode *N, SDNode *E) { 634 assert(N->getNodeId() != DAGTypeLegalizer::ReadyToProcess && 635 N->getNodeId() != DAGTypeLegalizer::Processed && 636 "Invalid node ID for RAUW deletion!"); 637 // It is possible, though rare, for the deleted node N to occur as a 638 // target in a map, so note the replacement N -> E in ReplacedValues. 639 assert(E && "Node not replaced?"); 640 DTL.NoteDeletion(N, E); 641 642 // In theory the deleted node could also have been scheduled for analysis. 643 // So add it to the set of nodes which will not be analyzed. 644 NodesDeleted.insert(N); 645 646 // In general nothing needs to be done for E, since it didn't change but 647 // only gained new uses. However N -> E was just added to ReplacedValues, 648 // and the result of a ReplacedValues mapping is not allowed to be marked 649 // NewNode. So if E is marked NewNode, then it needs to be analyzed. 650 if (E->getNodeId() == DAGTypeLegalizer::NewNode) 651 NodesToAnalyze.push_back(E); 652 } 653 654 virtual void NodeUpdated(SDNode *N) { 655 // Node updates can mean pretty much anything. It is possible that an 656 // operand was set to something already processed (f.e.) in which case 657 // this node could become ready. Recompute its flags. 658 assert(N->getNodeId() != DAGTypeLegalizer::ReadyToProcess && 659 N->getNodeId() != DAGTypeLegalizer::Processed && 660 "Invalid node ID for RAUW deletion!"); 661 NodesToAnalyze.push_back(N); 662 } 663 }; 664} 665 666 667/// ReplaceValueWith - The specified value was legalized to the specified other 668/// value. Update the DAG and NodeIds replacing any uses of From to use To 669/// instead. 670void DAGTypeLegalizer::ReplaceValueWith(SDValue From, SDValue To) { 671 assert(From.getNode()->getNodeId() == ReadyToProcess && 672 "Only the node being processed may be remapped!"); 673 assert(From.getNode() != To.getNode() && "Potential legalization loop!"); 674 675 // If expansion produced new nodes, make sure they are properly marked. 676 ExpungeNode(From.getNode()); 677 AnalyzeNewValue(To); // Expunges To. 678 679 // Anything that used the old node should now use the new one. Note that this 680 // can potentially cause recursive merging. 681 SmallVector<SDNode*, 16> NodesToAnalyze; 682 SmallPtrSet<SDNode*, 16> NodesDeleted; 683 NodeUpdateListener NUL(*this, NodesToAnalyze, NodesDeleted); 684 DAG.ReplaceAllUsesOfValueWith(From, To, &NUL); 685 686 // The old node may still be present in a map like ExpandedIntegers or 687 // PromotedIntegers. Inform maps about the replacement. 688 ReplacedValues[From] = To; 689 690 // Process the list of nodes that need to be reanalyzed. 691 while (!NodesToAnalyze.empty()) { 692 SDNode *N = NodesToAnalyze.back(); 693 NodesToAnalyze.pop_back(); 694 695 // Do not analyze deleted nodes! 696 if (NodesDeleted.count(N)) 697 continue; 698 699 // Analyze the node's operands and recalculate the node ID. 700 assert(N->getNodeId() != DAGTypeLegalizer::ReadyToProcess && 701 N->getNodeId() != DAGTypeLegalizer::Processed && 702 "Invalid node ID for RAUW analysis!"); 703 N->setNodeId(NewNode); 704 SDNode *M = AnalyzeNewNode(N); 705 if (M != N) { 706 // The node morphed into a different node. Make everyone use the new node 707 // 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 } 718 // The original node continues to exist in the DAG, marked NewNode. 719 } 720 } 721} 722 723void DAGTypeLegalizer::SetPromotedInteger(SDValue Op, SDValue Result) { 724 AnalyzeNewValue(Result); 725 726 SDValue &OpEntry = PromotedIntegers[Op]; 727 assert(OpEntry.getNode() == 0 && "Node is already promoted!"); 728 OpEntry = Result; 729} 730 731void DAGTypeLegalizer::SetSoftenedFloat(SDValue Op, SDValue Result) { 732 AnalyzeNewValue(Result); 733 734 SDValue &OpEntry = SoftenedFloats[Op]; 735 assert(OpEntry.getNode() == 0 && "Node is already converted to integer!"); 736 OpEntry = Result; 737} 738 739void DAGTypeLegalizer::SetScalarizedVector(SDValue Op, SDValue Result) { 740 AnalyzeNewValue(Result); 741 742 SDValue &OpEntry = ScalarizedVectors[Op]; 743 assert(OpEntry.getNode() == 0 && "Node is already scalarized!"); 744 OpEntry = Result; 745} 746 747void DAGTypeLegalizer::GetExpandedInteger(SDValue Op, SDValue &Lo, 748 SDValue &Hi) { 749 std::pair<SDValue, SDValue> &Entry = ExpandedIntegers[Op]; 750 RemapValue(Entry.first); 751 RemapValue(Entry.second); 752 assert(Entry.first.getNode() && "Operand isn't expanded"); 753 Lo = Entry.first; 754 Hi = Entry.second; 755} 756 757void DAGTypeLegalizer::SetExpandedInteger(SDValue Op, SDValue Lo, 758 SDValue Hi) { 759 // Lo/Hi may have been newly allocated, if so, add nodeid's as relevant. 760 AnalyzeNewValue(Lo); 761 AnalyzeNewValue(Hi); 762 763 // Remember that this is the result of the node. 764 std::pair<SDValue, SDValue> &Entry = ExpandedIntegers[Op]; 765 assert(Entry.first.getNode() == 0 && "Node already expanded"); 766 Entry.first = Lo; 767 Entry.second = Hi; 768} 769 770void DAGTypeLegalizer::GetExpandedFloat(SDValue Op, SDValue &Lo, 771 SDValue &Hi) { 772 std::pair<SDValue, SDValue> &Entry = ExpandedFloats[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 780void DAGTypeLegalizer::SetExpandedFloat(SDValue Op, SDValue Lo, 781 SDValue Hi) { 782 // Lo/Hi may have been newly allocated, if so, add nodeid's as relevant. 783 AnalyzeNewValue(Lo); 784 AnalyzeNewValue(Hi); 785 786 // Remember that this is the result of the node. 787 std::pair<SDValue, SDValue> &Entry = ExpandedFloats[Op]; 788 assert(Entry.first.getNode() == 0 && "Node already expanded"); 789 Entry.first = Lo; 790 Entry.second = Hi; 791} 792 793void DAGTypeLegalizer::GetSplitVector(SDValue Op, SDValue &Lo, 794 SDValue &Hi) { 795 std::pair<SDValue, SDValue> &Entry = SplitVectors[Op]; 796 RemapValue(Entry.first); 797 RemapValue(Entry.second); 798 assert(Entry.first.getNode() && "Operand isn't split"); 799 Lo = Entry.first; 800 Hi = Entry.second; 801} 802 803void DAGTypeLegalizer::SetSplitVector(SDValue Op, SDValue Lo, 804 SDValue Hi) { 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 = SplitVectors[Op]; 811 assert(Entry.first.getNode() == 0 && "Node already split"); 812 Entry.first = Lo; 813 Entry.second = Hi; 814} 815 816void DAGTypeLegalizer::SetWidenedVector(SDValue Op, SDValue Result) { 817 AnalyzeNewValue(Result); 818 819 SDValue &OpEntry = WidenedVectors[Op]; 820 assert(OpEntry.getNode() == 0 && "Node is already promoted!"); 821 OpEntry = Result; 822} 823 824// Set to ignore result 825void DAGTypeLegalizer::SetIgnoredNodeResult(SDNode* N) { 826 IgnoredNodesResultsSet.insert(N); 827} 828 829//===----------------------------------------------------------------------===// 830// Utilities. 831//===----------------------------------------------------------------------===// 832 833/// BitConvertToInteger - Convert to an integer of the same size. 834SDValue DAGTypeLegalizer::BitConvertToInteger(SDValue Op) { 835 unsigned BitWidth = Op.getValueType().getSizeInBits(); 836 return DAG.getNode(ISD::BIT_CONVERT, MVT::getIntegerVT(BitWidth), Op); 837} 838 839SDValue DAGTypeLegalizer::CreateStackStoreLoad(SDValue Op, 840 MVT DestVT) { 841 // Create the stack frame object. Make sure it is aligned for both 842 // the source and destination types. 843 SDValue StackPtr = DAG.CreateStackTemporary(Op.getValueType(), DestVT); 844 // Emit a store to the stack slot. 845 SDValue Store = DAG.getStore(DAG.getEntryNode(), Op, StackPtr, NULL, 0); 846 // Result is a load from the stack slot. 847 return DAG.getLoad(DestVT, Store, StackPtr, NULL, 0); 848} 849 850/// CustomLowerResults - Replace the node's results with custom code provided 851/// by the target and return "true", or do nothing and return "false". 852bool DAGTypeLegalizer::CustomLowerResults(SDNode *N, unsigned ResNo) { 853 // See if the target wants to custom lower this node. 854 if (TLI.getOperationAction(N->getOpcode(), N->getValueType(ResNo)) != 855 TargetLowering::Custom) 856 return false; 857 858 SmallVector<SDValue, 8> Results; 859 TLI.ReplaceNodeResults(N, Results, DAG); 860 if (Results.empty()) 861 // The target didn't want to custom lower it after all. 862 return false; 863 864 // Make everything that once used N's values now use those in Results instead. 865 assert(Results.size() == N->getNumValues() && 866 "Custom lowering returned the wrong number of results!"); 867 for (unsigned i = 0, e = Results.size(); i != e; ++i) 868 ReplaceValueWith(SDValue(N, i), Results[i]); 869 return true; 870} 871 872/// JoinIntegers - Build an integer with low bits Lo and high bits Hi. 873SDValue DAGTypeLegalizer::JoinIntegers(SDValue Lo, SDValue Hi) { 874 MVT LVT = Lo.getValueType(); 875 MVT HVT = Hi.getValueType(); 876 MVT NVT = MVT::getIntegerVT(LVT.getSizeInBits() + HVT.getSizeInBits()); 877 878 Lo = DAG.getNode(ISD::ZERO_EXTEND, NVT, Lo); 879 Hi = DAG.getNode(ISD::ANY_EXTEND, NVT, Hi); 880 Hi = DAG.getNode(ISD::SHL, NVT, Hi, DAG.getConstant(LVT.getSizeInBits(), 881 TLI.getShiftAmountTy())); 882 return DAG.getNode(ISD::OR, NVT, Lo, Hi); 883} 884 885/// SplitInteger - Return the lower LoVT bits of Op in Lo and the upper HiVT 886/// bits in Hi. 887void DAGTypeLegalizer::SplitInteger(SDValue Op, 888 MVT LoVT, MVT HiVT, 889 SDValue &Lo, SDValue &Hi) { 890 assert(LoVT.getSizeInBits() + HiVT.getSizeInBits() == 891 Op.getValueType().getSizeInBits() && "Invalid integer splitting!"); 892 Lo = DAG.getNode(ISD::TRUNCATE, LoVT, Op); 893 Hi = DAG.getNode(ISD::SRL, Op.getValueType(), Op, 894 DAG.getConstant(LoVT.getSizeInBits(), 895 TLI.getShiftAmountTy())); 896 Hi = DAG.getNode(ISD::TRUNCATE, HiVT, Hi); 897} 898 899/// SplitInteger - Return the lower and upper halves of Op's bits in a value 900/// type half the size of Op's. 901void DAGTypeLegalizer::SplitInteger(SDValue Op, 902 SDValue &Lo, SDValue &Hi) { 903 MVT HalfVT = MVT::getIntegerVT(Op.getValueType().getSizeInBits()/2); 904 SplitInteger(Op, HalfVT, HalfVT, Lo, Hi); 905} 906 907/// MakeLibCall - Generate a libcall taking the given operands as arguments and 908/// returning a result of type RetVT. 909SDValue DAGTypeLegalizer::MakeLibCall(RTLIB::Libcall LC, MVT RetVT, 910 const SDValue *Ops, unsigned NumOps, 911 bool isSigned) { 912 TargetLowering::ArgListTy Args; 913 Args.reserve(NumOps); 914 915 TargetLowering::ArgListEntry Entry; 916 for (unsigned i = 0; i != NumOps; ++i) { 917 Entry.Node = Ops[i]; 918 Entry.Ty = Entry.Node.getValueType().getTypeForMVT(); 919 Entry.isSExt = isSigned; 920 Entry.isZExt = !isSigned; 921 Args.push_back(Entry); 922 } 923 SDValue Callee = DAG.getExternalSymbol(TLI.getLibcallName(LC), 924 TLI.getPointerTy()); 925 926 const Type *RetTy = RetVT.getTypeForMVT(); 927 std::pair<SDValue,SDValue> CallInfo = 928 TLI.LowerCallTo(DAG.getEntryNode(), RetTy, isSigned, !isSigned, false, 929 false, CallingConv::C, false, Callee, Args, DAG); 930 return CallInfo.first; 931} 932 933/// LibCallify - Convert the node into a libcall with the same prototype. 934SDValue DAGTypeLegalizer::LibCallify(RTLIB::Libcall LC, SDNode *N, 935 bool isSigned) { 936 unsigned NumOps = N->getNumOperands(); 937 if (NumOps == 0) { 938 return MakeLibCall(LC, N->getValueType(0), 0, 0, isSigned); 939 } else if (NumOps == 1) { 940 SDValue Op = N->getOperand(0); 941 return MakeLibCall(LC, N->getValueType(0), &Op, 1, isSigned); 942 } else if (NumOps == 2) { 943 SDValue Ops[2] = { N->getOperand(0), N->getOperand(1) }; 944 return MakeLibCall(LC, N->getValueType(0), Ops, 2, isSigned); 945 } 946 SmallVector<SDValue, 8> Ops(NumOps); 947 for (unsigned i = 0; i < NumOps; ++i) 948 Ops[i] = N->getOperand(i); 949 950 return MakeLibCall(LC, N->getValueType(0), &Ops[0], NumOps, isSigned); 951} 952 953SDValue DAGTypeLegalizer::GetVectorElementPointer(SDValue VecPtr, MVT EltVT, 954 SDValue Index) { 955 // Make sure the index type is big enough to compute in. 956 if (Index.getValueType().bitsGT(TLI.getPointerTy())) 957 Index = DAG.getNode(ISD::TRUNCATE, TLI.getPointerTy(), Index); 958 else 959 Index = DAG.getNode(ISD::ZERO_EXTEND, TLI.getPointerTy(), Index); 960 961 // Calculate the element offset and add it to the pointer. 962 unsigned EltSize = EltVT.getSizeInBits() / 8; // FIXME: should be ABI size. 963 964 Index = DAG.getNode(ISD::MUL, Index.getValueType(), Index, 965 DAG.getConstant(EltSize, Index.getValueType())); 966 return DAG.getNode(ISD::ADD, Index.getValueType(), Index, VecPtr); 967} 968 969/// GetSplitDestVTs - Compute the VTs needed for the low/hi parts of a type 970/// which is split into two not necessarily identical pieces. 971void DAGTypeLegalizer::GetSplitDestVTs(MVT InVT, MVT &LoVT, MVT &HiVT) { 972 if (!InVT.isVector()) { 973 LoVT = HiVT = TLI.getTypeToTransformTo(InVT); 974 } else { 975 MVT NewEltVT = InVT.getVectorElementType(); 976 unsigned NumElements = InVT.getVectorNumElements(); 977 if ((NumElements & (NumElements-1)) == 0) { // Simple power of two vector. 978 NumElements >>= 1; 979 LoVT = HiVT = MVT::getVectorVT(NewEltVT, NumElements); 980 } else { // Non-power-of-two vectors. 981 unsigned NewNumElts_Lo = 1 << Log2_32(NumElements); 982 unsigned NewNumElts_Hi = NumElements - NewNumElts_Lo; 983 LoVT = MVT::getVectorVT(NewEltVT, NewNumElts_Lo); 984 HiVT = MVT::getVectorVT(NewEltVT, NewNumElts_Hi); 985 } 986 } 987} 988 989 990//===----------------------------------------------------------------------===// 991// Entry Point 992//===----------------------------------------------------------------------===// 993 994/// LegalizeTypes - This transforms the SelectionDAG into a SelectionDAG that 995/// only uses types natively supported by the target. Returns "true" if it made 996/// any changes. 997/// 998/// Note that this is an involved process that may invalidate pointers into 999/// the graph. 1000bool SelectionDAG::LegalizeTypes() { 1001 return DAGTypeLegalizer(*this).run(); 1002} 1003