LegalizeTypes.cpp revision c8fc99d66a03dc603f49d653937ad1d94e833006
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/SetVector.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().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. However 332 // there is no need to remember the replacement - morphing will make sure 333 // it is never used non-trivially. 334 assert(N->getNumValues() == M->getNumValues() && 335 "Node morphing changed the number of results!"); 336 for (unsigned i = 0, e = N->getNumValues(); i != e; ++i) 337 // Replacing the value takes care of remapping the new value. Do the 338 // replacement without recording it in ReplacedValues. This does not 339 // expunge From but that is fine - it is not really a new node. 340 ReplaceValueWithHelper(SDValue(N, i), SDValue(M, i)); 341 assert(N->getNodeId() == NewNode && "Unexpected node state!"); 342 // The node continues to live on as part of the NewNode fungus that 343 // grows on top of the useful nodes. Nothing more needs to be done 344 // with it - move on to the next node. 345 continue; 346 } 347 348 if (i == NumOperands) { 349 DEBUG(cerr << "Legally typed node: "; N->dump(&DAG); cerr << "\n"); 350 } 351 } 352NodeDone: 353 354 // If we reach here, the node was processed, potentially creating new nodes. 355 // Mark it as processed and add its users to the worklist as appropriate. 356 assert(N->getNodeId() == ReadyToProcess && "Node ID recalculated?"); 357 N->setNodeId(Processed); 358 359 for (SDNode::use_iterator UI = N->use_begin(), E = N->use_end(); 360 UI != E; ++UI) { 361 SDNode *User = *UI; 362 int NodeId = User->getNodeId(); 363 364 // This node has two options: it can either be a new node or its Node ID 365 // may be a count of the number of operands it has that are not ready. 366 if (NodeId > 0) { 367 User->setNodeId(NodeId-1); 368 369 // If this was the last use it was waiting on, add it to the ready list. 370 if (NodeId-1 == ReadyToProcess) 371 Worklist.push_back(User); 372 continue; 373 } 374 375 // If this is an unreachable new node, then ignore it. If it ever becomes 376 // reachable by being used by a newly created node then it will be handled 377 // by AnalyzeNewNode. 378 if (NodeId == NewNode) 379 continue; 380 381 // Otherwise, this node is new: this is the first operand of it that 382 // became ready. Its new NodeId is the number of operands it has minus 1 383 // (as this node is now processed). 384 assert(NodeId == Unanalyzed && "Unknown node ID!"); 385 User->setNodeId(User->getNumOperands() - 1); 386 387 // If the node only has a single operand, it is now ready. 388 if (User->getNumOperands() == 1) 389 Worklist.push_back(User); 390 } 391 } 392 393#ifndef XDEBUG 394 if (EnableExpensiveChecks) 395#endif 396 PerformExpensiveChecks(); 397 398 // If the root changed (e.g. it was a dead load) update the root. 399 DAG.setRoot(Dummy.getValue()); 400 401 // Remove dead nodes. This is important to do for cleanliness but also before 402 // the checking loop below. Implicit folding by the DAG.getNode operators and 403 // node morphing can cause unreachable nodes to be around with their flags set 404 // to new. 405 DAG.RemoveDeadNodes(); 406 407 // In a debug build, scan all the nodes to make sure we found them all. This 408 // ensures that there are no cycles and that everything got processed. 409#ifndef NDEBUG 410 for (SelectionDAG::allnodes_iterator I = DAG.allnodes_begin(), 411 E = DAG.allnodes_end(); I != E; ++I) { 412 bool Failed = false; 413 414 // Check that all result types are legal. 415 if (!IgnoreNodeResults(I)) 416 for (unsigned i = 0, NumVals = I->getNumValues(); i < NumVals; ++i) 417 if (!isTypeLegal(I->getValueType(i))) { 418 cerr << "Result type " << i << " illegal!\n"; 419 Failed = true; 420 } 421 422 // Check that all operand types are legal. 423 for (unsigned i = 0, NumOps = I->getNumOperands(); i < NumOps; ++i) 424 if (!IgnoreNodeResults(I->getOperand(i).getNode()) && 425 !isTypeLegal(I->getOperand(i).getValueType())) { 426 cerr << "Operand type " << i << " illegal!\n"; 427 Failed = true; 428 } 429 430 if (I->getNodeId() != Processed) { 431 if (I->getNodeId() == NewNode) 432 cerr << "New node not analyzed?\n"; 433 else if (I->getNodeId() == Unanalyzed) 434 cerr << "Unanalyzed node not noticed?\n"; 435 else if (I->getNodeId() > 0) 436 cerr << "Operand not processed?\n"; 437 else if (I->getNodeId() == ReadyToProcess) 438 cerr << "Not added to worklist?\n"; 439 Failed = true; 440 } 441 442 if (Failed) { 443 I->dump(&DAG); cerr << "\n"; 444 abort(); 445 } 446 } 447#endif 448 449 return Changed; 450} 451 452/// AnalyzeNewNode - The specified node is the root of a subtree of potentially 453/// new nodes. Correct any processed operands (this may change the node) and 454/// calculate the NodeId. If the node itself changes to a processed node, it 455/// is not remapped - the caller needs to take care of this. 456/// Returns the potentially changed node. 457SDNode *DAGTypeLegalizer::AnalyzeNewNode(SDNode *N) { 458 // If this was an existing node that is already done, we're done. 459 if (N->getNodeId() != NewNode && N->getNodeId() != Unanalyzed) 460 return N; 461 462 // Remove any stale map entries. 463 ExpungeNode(N); 464 465 // Okay, we know that this node is new. Recursively walk all of its operands 466 // to see if they are new also. The depth of this walk is bounded by the size 467 // of the new tree that was constructed (usually 2-3 nodes), so we don't worry 468 // about revisiting of nodes. 469 // 470 // As we walk the operands, keep track of the number of nodes that are 471 // processed. If non-zero, this will become the new nodeid of this node. 472 // Operands may morph when they are analyzed. If so, the node will be 473 // updated after all operands have been analyzed. Since this is rare, 474 // the code tries to minimize overhead in the non-morphing case. 475 476 SmallVector<SDValue, 8> NewOps; 477 unsigned NumProcessed = 0; 478 for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i) { 479 SDValue OrigOp = N->getOperand(i); 480 SDValue Op = OrigOp; 481 482 AnalyzeNewValue(Op); // Op may morph. 483 484 if (Op.getNode()->getNodeId() == Processed) 485 ++NumProcessed; 486 487 if (!NewOps.empty()) { 488 // Some previous operand changed. Add this one to the list. 489 NewOps.push_back(Op); 490 } else if (Op != OrigOp) { 491 // This is the first operand to change - add all operands so far. 492 for (unsigned j = 0; j < i; ++j) 493 NewOps.push_back(N->getOperand(j)); 494 NewOps.push_back(Op); 495 } 496 } 497 498 // Some operands changed - update the node. 499 if (!NewOps.empty()) { 500 SDNode *M = DAG.UpdateNodeOperands(SDValue(N, 0), &NewOps[0], 501 NewOps.size()).getNode(); 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. 531void 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). 551void 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. 621void 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 assert(N.getNode()->getNodeId() != NewNode && "Mapped to new node!"); 629 } 630} 631 632namespace { 633 /// NodeUpdateListener - This class is a DAGUpdateListener that listens for 634 /// updates to nodes and recomputes their ready state. 635 class VISIBILITY_HIDDEN NodeUpdateListener : 636 public SelectionDAG::DAGUpdateListener { 637 DAGTypeLegalizer &DTL; 638 SmallSetVector<SDNode*, 16> &NodesToAnalyze; 639 public: 640 explicit NodeUpdateListener(DAGTypeLegalizer &dtl, 641 SmallSetVector<SDNode*, 16> &nta) 642 : DTL(dtl), NodesToAnalyze(nta) {} 643 644 virtual void NodeDeleted(SDNode *N, SDNode *E) { 645 assert(N->getNodeId() != DAGTypeLegalizer::ReadyToProcess && 646 N->getNodeId() != DAGTypeLegalizer::Processed && 647 "Invalid node ID for RAUW deletion!"); 648 // It is possible, though rare, for the deleted node N to occur as a 649 // target in a map, so note the replacement N -> E in ReplacedValues. 650 assert(E && "Node not replaced?"); 651 DTL.NoteDeletion(N, E); 652 653 // In theory the deleted node could also have been scheduled for analysis. 654 // So add it to the set of nodes which will not be analyzed. 655 NodesToAnalyze.remove(N); 656 657 // In general nothing needs to be done for E, since it didn't change but 658 // only gained new uses. However N -> E was just added to ReplacedValues, 659 // and the result of a ReplacedValues mapping is not allowed to be marked 660 // NewNode. So if E is marked NewNode, then it needs to be analyzed. 661 if (E->getNodeId() == DAGTypeLegalizer::NewNode) 662 NodesToAnalyze.insert(E); 663 } 664 665 virtual void NodeUpdated(SDNode *N) { 666 // Node updates can mean pretty much anything. It is possible that an 667 // operand was set to something already processed (f.e.) in which case 668 // this node could become ready. Recompute its flags. 669 assert(N->getNodeId() != DAGTypeLegalizer::ReadyToProcess && 670 N->getNodeId() != DAGTypeLegalizer::Processed && 671 "Invalid node ID for RAUW deletion!"); 672 NodesToAnalyze.insert(N); 673 } 674 }; 675} 676 677 678/// ReplaceValueWithHelper - Internal helper for ReplaceValueWith. Updates the 679/// DAG causing any uses of From to use To instead, but without expunging From 680/// or recording the replacement in ReplacedValues. Do not call directly unless 681/// you really know what you are doing! 682void DAGTypeLegalizer::ReplaceValueWithHelper(SDValue From, SDValue To) { 683 assert(From.getNode() != To.getNode() && "Potential legalization loop!"); 684 685 // If expansion produced new nodes, make sure they are properly marked. 686 AnalyzeNewValue(To); // Expunges To. 687 688 // Anything that used the old node should now use the new one. Note that this 689 // can potentially cause recursive merging. 690 SmallSetVector<SDNode*, 16> NodesToAnalyze; 691 NodeUpdateListener NUL(*this, NodesToAnalyze); 692 DAG.ReplaceAllUsesOfValueWith(From, To, &NUL); 693 694 // Process the list of nodes that need to be reanalyzed. 695 while (!NodesToAnalyze.empty()) { 696 SDNode *N = NodesToAnalyze.back(); 697 NodesToAnalyze.pop_back(); 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} 722 723/// ReplaceValueWith - The specified value was legalized to the specified other 724/// value. Update the DAG and NodeIds replacing any uses of From to use To 725/// instead. 726void DAGTypeLegalizer::ReplaceValueWith(SDValue From, SDValue To) { 727 assert(From.getNode()->getNodeId() == ReadyToProcess && 728 "Only the node being processed may be remapped!"); 729 730 // If expansion produced new nodes, make sure they are properly marked. 731 ExpungeNode(From.getNode()); 732 AnalyzeNewValue(To); // Expunges To. 733 734 // The old node may still be present in a map like ExpandedIntegers or 735 // PromotedIntegers. Inform maps about the replacement. 736 ReplacedValues[From] = To; 737 738 // Do the replacement. 739 ReplaceValueWithHelper(From, To); 740} 741 742void DAGTypeLegalizer::SetPromotedInteger(SDValue Op, SDValue Result) { 743 AnalyzeNewValue(Result); 744 745 SDValue &OpEntry = PromotedIntegers[Op]; 746 assert(OpEntry.getNode() == 0 && "Node is already promoted!"); 747 OpEntry = Result; 748} 749 750void DAGTypeLegalizer::SetSoftenedFloat(SDValue Op, SDValue Result) { 751 AnalyzeNewValue(Result); 752 753 SDValue &OpEntry = SoftenedFloats[Op]; 754 assert(OpEntry.getNode() == 0 && "Node is already converted to integer!"); 755 OpEntry = Result; 756} 757 758void DAGTypeLegalizer::SetScalarizedVector(SDValue Op, SDValue Result) { 759 AnalyzeNewValue(Result); 760 761 SDValue &OpEntry = ScalarizedVectors[Op]; 762 assert(OpEntry.getNode() == 0 && "Node is already scalarized!"); 763 OpEntry = Result; 764} 765 766void DAGTypeLegalizer::GetExpandedInteger(SDValue Op, SDValue &Lo, 767 SDValue &Hi) { 768 std::pair<SDValue, SDValue> &Entry = ExpandedIntegers[Op]; 769 RemapValue(Entry.first); 770 RemapValue(Entry.second); 771 assert(Entry.first.getNode() && "Operand isn't expanded"); 772 Lo = Entry.first; 773 Hi = Entry.second; 774} 775 776void DAGTypeLegalizer::SetExpandedInteger(SDValue Op, SDValue Lo, 777 SDValue Hi) { 778 // Lo/Hi may have been newly allocated, if so, add nodeid's as relevant. 779 AnalyzeNewValue(Lo); 780 AnalyzeNewValue(Hi); 781 782 // Remember that this is the result of the node. 783 std::pair<SDValue, SDValue> &Entry = ExpandedIntegers[Op]; 784 assert(Entry.first.getNode() == 0 && "Node already expanded"); 785 Entry.first = Lo; 786 Entry.second = Hi; 787} 788 789void DAGTypeLegalizer::GetExpandedFloat(SDValue Op, SDValue &Lo, 790 SDValue &Hi) { 791 std::pair<SDValue, SDValue> &Entry = ExpandedFloats[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 799void DAGTypeLegalizer::SetExpandedFloat(SDValue Op, SDValue Lo, 800 SDValue Hi) { 801 // Lo/Hi may have been newly allocated, if so, add nodeid's as relevant. 802 AnalyzeNewValue(Lo); 803 AnalyzeNewValue(Hi); 804 805 // Remember that this is the result of the node. 806 std::pair<SDValue, SDValue> &Entry = ExpandedFloats[Op]; 807 assert(Entry.first.getNode() == 0 && "Node already expanded"); 808 Entry.first = Lo; 809 Entry.second = Hi; 810} 811 812void DAGTypeLegalizer::GetSplitVector(SDValue Op, SDValue &Lo, 813 SDValue &Hi) { 814 std::pair<SDValue, SDValue> &Entry = SplitVectors[Op]; 815 RemapValue(Entry.first); 816 RemapValue(Entry.second); 817 assert(Entry.first.getNode() && "Operand isn't split"); 818 Lo = Entry.first; 819 Hi = Entry.second; 820} 821 822void DAGTypeLegalizer::SetSplitVector(SDValue Op, SDValue Lo, 823 SDValue Hi) { 824 // Lo/Hi may have been newly allocated, if so, add nodeid's as relevant. 825 AnalyzeNewValue(Lo); 826 AnalyzeNewValue(Hi); 827 828 // Remember that this is the result of the node. 829 std::pair<SDValue, SDValue> &Entry = SplitVectors[Op]; 830 assert(Entry.first.getNode() == 0 && "Node already split"); 831 Entry.first = Lo; 832 Entry.second = Hi; 833} 834 835void DAGTypeLegalizer::SetWidenedVector(SDValue Op, SDValue Result) { 836 AnalyzeNewValue(Result); 837 838 SDValue &OpEntry = WidenedVectors[Op]; 839 assert(OpEntry.getNode() == 0 && "Node already widened!"); 840 OpEntry = Result; 841} 842 843// Set to ignore result 844void DAGTypeLegalizer::SetIgnoredNodeResult(SDNode* N) { 845 IgnoredNodesResultsSet.insert(N); 846} 847 848//===----------------------------------------------------------------------===// 849// Utilities. 850//===----------------------------------------------------------------------===// 851 852/// BitConvertToInteger - Convert to an integer of the same size. 853SDValue DAGTypeLegalizer::BitConvertToInteger(SDValue Op) { 854 unsigned BitWidth = Op.getValueType().getSizeInBits(); 855 return DAG.getNode(ISD::BIT_CONVERT, MVT::getIntegerVT(BitWidth), Op); 856} 857 858SDValue DAGTypeLegalizer::CreateStackStoreLoad(SDValue Op, 859 MVT DestVT) { 860 // Create the stack frame object. Make sure it is aligned for both 861 // the source and destination types. 862 SDValue StackPtr = DAG.CreateStackTemporary(Op.getValueType(), DestVT); 863 // Emit a store to the stack slot. 864 SDValue Store = DAG.getStore(DAG.getEntryNode(), Op, StackPtr, NULL, 0); 865 // Result is a load from the stack slot. 866 return DAG.getLoad(DestVT, Store, StackPtr, NULL, 0); 867} 868 869/// CustomLowerResults - Replace the node's results with custom code provided 870/// by the target and return "true", or do nothing and return "false". 871/// The last parameter is FALSE if we are dealing with a node with legal 872/// result types and illegal operand. The second parameter denotes the illegal 873/// OperandNo in that case. 874/// The last parameter being TRUE means we are dealing with a 875/// node with illegal result types. The second parameter denotes the illegal 876/// ResNo in that case. 877bool DAGTypeLegalizer::CustomLowerResults(SDNode *N, MVT VT, 878 bool LegalizeResult) { 879 // See if the target wants to custom lower this node. 880 if (TLI.getOperationAction(N->getOpcode(), VT) != TargetLowering::Custom) 881 return false; 882 883 SmallVector<SDValue, 8> Results; 884 if (LegalizeResult) 885 TLI.ReplaceNodeResults(N, Results, DAG); 886 else 887 TLI.LowerOperationWrapper(N, Results, DAG); 888 889 if (Results.empty()) 890 // The target didn't want to custom lower it after all. 891 return false; 892 893 // Make everything that once used N's values now use those in Results instead. 894 assert(Results.size() == N->getNumValues() && 895 "Custom lowering returned the wrong number of results!"); 896 for (unsigned i = 0, e = Results.size(); i != e; ++i) 897 ReplaceValueWith(SDValue(N, i), Results[i]); 898 return true; 899} 900 901/// GetSplitDestVTs - Compute the VTs needed for the low/hi parts of a type 902/// which is split into two not necessarily identical pieces. 903void DAGTypeLegalizer::GetSplitDestVTs(MVT InVT, MVT &LoVT, MVT &HiVT) { 904 if (!InVT.isVector()) { 905 LoVT = HiVT = TLI.getTypeToTransformTo(InVT); 906 } else { 907 MVT NewEltVT = InVT.getVectorElementType(); 908 unsigned NumElements = InVT.getVectorNumElements(); 909 if ((NumElements & (NumElements-1)) == 0) { // Simple power of two vector. 910 NumElements >>= 1; 911 LoVT = HiVT = MVT::getVectorVT(NewEltVT, NumElements); 912 } else { // Non-power-of-two vectors. 913 unsigned NewNumElts_Lo = 1 << Log2_32(NumElements); 914 unsigned NewNumElts_Hi = NumElements - NewNumElts_Lo; 915 LoVT = MVT::getVectorVT(NewEltVT, NewNumElts_Lo); 916 HiVT = MVT::getVectorVT(NewEltVT, NewNumElts_Hi); 917 } 918 } 919} 920 921SDValue DAGTypeLegalizer::GetVectorElementPointer(SDValue VecPtr, MVT EltVT, 922 SDValue Index) { 923 // Make sure the index type is big enough to compute in. 924 if (Index.getValueType().bitsGT(TLI.getPointerTy())) 925 Index = DAG.getNode(ISD::TRUNCATE, TLI.getPointerTy(), Index); 926 else 927 Index = DAG.getNode(ISD::ZERO_EXTEND, TLI.getPointerTy(), Index); 928 929 // Calculate the element offset and add it to the pointer. 930 unsigned EltSize = EltVT.getSizeInBits() / 8; // FIXME: should be ABI size. 931 932 Index = DAG.getNode(ISD::MUL, Index.getValueType(), Index, 933 DAG.getConstant(EltSize, Index.getValueType())); 934 return DAG.getNode(ISD::ADD, Index.getValueType(), Index, VecPtr); 935} 936 937/// JoinIntegers - Build an integer with low bits Lo and high bits Hi. 938SDValue DAGTypeLegalizer::JoinIntegers(SDValue Lo, SDValue Hi) { 939 MVT LVT = Lo.getValueType(); 940 MVT HVT = Hi.getValueType(); 941 MVT NVT = MVT::getIntegerVT(LVT.getSizeInBits() + HVT.getSizeInBits()); 942 943 Lo = DAG.getNode(ISD::ZERO_EXTEND, NVT, Lo); 944 Hi = DAG.getNode(ISD::ANY_EXTEND, NVT, Hi); 945 Hi = DAG.getNode(ISD::SHL, NVT, Hi, DAG.getConstant(LVT.getSizeInBits(), 946 TLI.getShiftAmountTy())); 947 return DAG.getNode(ISD::OR, NVT, Lo, Hi); 948} 949 950/// LibCallify - Convert the node into a libcall with the same prototype. 951SDValue DAGTypeLegalizer::LibCallify(RTLIB::Libcall LC, SDNode *N, 952 bool isSigned) { 953 unsigned NumOps = N->getNumOperands(); 954 DebugLoc dl = N->getDebugLoc(); 955 if (NumOps == 0) { 956 return MakeLibCall(LC, N->getValueType(0), 0, 0, isSigned, dl); 957 } else if (NumOps == 1) { 958 SDValue Op = N->getOperand(0); 959 return MakeLibCall(LC, N->getValueType(0), &Op, 1, isSigned, dl); 960 } else if (NumOps == 2) { 961 SDValue Ops[2] = { N->getOperand(0), N->getOperand(1) }; 962 return MakeLibCall(LC, N->getValueType(0), Ops, 2, isSigned, dl); 963 } 964 SmallVector<SDValue, 8> Ops(NumOps); 965 for (unsigned i = 0; i < NumOps; ++i) 966 Ops[i] = N->getOperand(i); 967 968 return MakeLibCall(LC, N->getValueType(0), &Ops[0], NumOps, isSigned, dl); 969} 970 971/// MakeLibCall - Generate a libcall taking the given operands as arguments and 972/// returning a result of type RetVT. 973SDValue DAGTypeLegalizer::MakeLibCall(RTLIB::Libcall LC, MVT RetVT, 974 const SDValue *Ops, unsigned NumOps, 975 bool isSigned, DebugLoc dl) { 976 TargetLowering::ArgListTy Args; 977 Args.reserve(NumOps); 978 979 TargetLowering::ArgListEntry Entry; 980 for (unsigned i = 0; i != NumOps; ++i) { 981 Entry.Node = Ops[i]; 982 Entry.Ty = Entry.Node.getValueType().getTypeForMVT(); 983 Entry.isSExt = isSigned; 984 Entry.isZExt = !isSigned; 985 Args.push_back(Entry); 986 } 987 SDValue Callee = DAG.getExternalSymbol(TLI.getLibcallName(LC), 988 TLI.getPointerTy()); 989 990 const Type *RetTy = RetVT.getTypeForMVT(); 991 std::pair<SDValue,SDValue> CallInfo = 992 TLI.LowerCallTo(DAG.getEntryNode(), RetTy, isSigned, !isSigned, false, 993 false, CallingConv::C, false, Callee, Args, DAG, dl); 994 return CallInfo.first; 995} 996 997/// PromoteTargetBoolean - Promote the given target boolean to a target boolean 998/// of the given type. A target boolean is an integer value, not necessarily of 999/// type i1, the bits of which conform to getBooleanContents. 1000SDValue DAGTypeLegalizer::PromoteTargetBoolean(SDValue Bool, MVT VT) { 1001 ISD::NodeType ExtendCode; 1002 switch (TLI.getBooleanContents()) { 1003 default: 1004 assert(false && "Unknown BooleanContent!"); 1005 case TargetLowering::UndefinedBooleanContent: 1006 // Extend to VT by adding rubbish bits. 1007 ExtendCode = ISD::ANY_EXTEND; 1008 break; 1009 case TargetLowering::ZeroOrOneBooleanContent: 1010 // Extend to VT by adding zero bits. 1011 ExtendCode = ISD::ZERO_EXTEND; 1012 break; 1013 case TargetLowering::ZeroOrNegativeOneBooleanContent: { 1014 // Extend to VT by copying the sign bit. 1015 ExtendCode = ISD::SIGN_EXTEND; 1016 break; 1017 } 1018 } 1019 return DAG.getNode(ExtendCode, VT, Bool); 1020} 1021 1022/// SplitInteger - Return the lower LoVT bits of Op in Lo and the upper HiVT 1023/// bits in Hi. 1024void DAGTypeLegalizer::SplitInteger(SDValue Op, 1025 MVT LoVT, MVT HiVT, 1026 SDValue &Lo, SDValue &Hi) { 1027 assert(LoVT.getSizeInBits() + HiVT.getSizeInBits() == 1028 Op.getValueType().getSizeInBits() && "Invalid integer splitting!"); 1029 Lo = DAG.getNode(ISD::TRUNCATE, LoVT, Op); 1030 Hi = DAG.getNode(ISD::SRL, Op.getValueType(), Op, 1031 DAG.getConstant(LoVT.getSizeInBits(), 1032 TLI.getShiftAmountTy())); 1033 Hi = DAG.getNode(ISD::TRUNCATE, HiVT, Hi); 1034} 1035 1036/// SplitInteger - Return the lower and upper halves of Op's bits in a value 1037/// type half the size of Op's. 1038void DAGTypeLegalizer::SplitInteger(SDValue Op, 1039 SDValue &Lo, SDValue &Hi) { 1040 MVT HalfVT = MVT::getIntegerVT(Op.getValueType().getSizeInBits()/2); 1041 SplitInteger(Op, HalfVT, HalfVT, Lo, Hi); 1042} 1043 1044 1045//===----------------------------------------------------------------------===// 1046// Entry Point 1047//===----------------------------------------------------------------------===// 1048 1049/// LegalizeTypes - This transforms the SelectionDAG into a SelectionDAG that 1050/// only uses types natively supported by the target. Returns "true" if it made 1051/// any changes. 1052/// 1053/// Note that this is an involved process that may invalidate pointers into 1054/// the graph. 1055bool SelectionDAG::LegalizeTypes() { 1056 return DAGTypeLegalizer(*this).run(); 1057} 1058