1249259Sdim//===-- BasicBlock.cpp - Implement BasicBlock related methods -------------===// 2249259Sdim// 3353358Sdim// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4353358Sdim// See https://llvm.org/LICENSE.txt for license information. 5353358Sdim// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6249259Sdim// 7249259Sdim//===----------------------------------------------------------------------===// 8249259Sdim// 9249259Sdim// This file implements the BasicBlock class for the IR library. 10249259Sdim// 11249259Sdim//===----------------------------------------------------------------------===// 12249259Sdim 13249259Sdim#include "llvm/IR/BasicBlock.h" 14249259Sdim#include "SymbolTableListTraitsImpl.h" 15249259Sdim#include "llvm/ADT/STLExtras.h" 16276479Sdim#include "llvm/IR/CFG.h" 17249259Sdim#include "llvm/IR/Constants.h" 18249259Sdim#include "llvm/IR/Instructions.h" 19249259Sdim#include "llvm/IR/IntrinsicInst.h" 20249259Sdim#include "llvm/IR/LLVMContext.h" 21249259Sdim#include "llvm/IR/Type.h" 22249259Sdim#include <algorithm> 23296417Sdim 24249259Sdimusing namespace llvm; 25249259Sdim 26249259SdimValueSymbolTable *BasicBlock::getValueSymbolTable() { 27249259Sdim if (Function *F = getParent()) 28314564Sdim return F->getValueSymbolTable(); 29276479Sdim return nullptr; 30249259Sdim} 31249259Sdim 32249259SdimLLVMContext &BasicBlock::getContext() const { 33249259Sdim return getType()->getContext(); 34249259Sdim} 35249259Sdim 36249259Sdim// Explicit instantiation of SymbolTableListTraits since some of the methods 37249259Sdim// are not in the public header file... 38296417Sdimtemplate class llvm::SymbolTableListTraits<Instruction>; 39249259Sdim 40249259SdimBasicBlock::BasicBlock(LLVMContext &C, const Twine &Name, Function *NewParent, 41249259Sdim BasicBlock *InsertBefore) 42276479Sdim : Value(Type::getLabelTy(C), Value::BasicBlockVal), Parent(nullptr) { 43249259Sdim 44280031Sdim if (NewParent) 45280031Sdim insertInto(NewParent, InsertBefore); 46280031Sdim else 47280031Sdim assert(!InsertBefore && 48249259Sdim "Cannot insert block before another block with no function!"); 49249259Sdim 50249259Sdim setName(Name); 51249259Sdim} 52249259Sdim 53280031Sdimvoid BasicBlock::insertInto(Function *NewParent, BasicBlock *InsertBefore) { 54280031Sdim assert(NewParent && "Expected a parent"); 55280031Sdim assert(!Parent && "Already has a parent"); 56249259Sdim 57280031Sdim if (InsertBefore) 58296417Sdim NewParent->getBasicBlockList().insert(InsertBefore->getIterator(), this); 59280031Sdim else 60280031Sdim NewParent->getBasicBlockList().push_back(this); 61280031Sdim} 62280031Sdim 63249259SdimBasicBlock::~BasicBlock() { 64249259Sdim // If the address of the block is taken and it is being deleted (e.g. because 65249259Sdim // it is dead), this means that there is either a dangling constant expr 66249259Sdim // hanging off the block, or an undefined use of the block (source code 67249259Sdim // expecting the address of a label to keep the block alive even though there 68249259Sdim // is no indirect branch). Handle these cases by zapping the BlockAddress 69249259Sdim // nodes. There are no other possible uses at this point. 70249259Sdim if (hasAddressTaken()) { 71249259Sdim assert(!use_empty() && "There should be at least one blockaddress!"); 72249259Sdim Constant *Replacement = 73249259Sdim ConstantInt::get(llvm::Type::getInt32Ty(getContext()), 1); 74249259Sdim while (!use_empty()) { 75276479Sdim BlockAddress *BA = cast<BlockAddress>(user_back()); 76249259Sdim BA->replaceAllUsesWith(ConstantExpr::getIntToPtr(Replacement, 77249259Sdim BA->getType())); 78249259Sdim BA->destroyConstant(); 79249259Sdim } 80249259Sdim } 81249259Sdim 82276479Sdim assert(getParent() == nullptr && "BasicBlock still linked into the program!"); 83249259Sdim dropAllReferences(); 84249259Sdim InstList.clear(); 85249259Sdim} 86249259Sdim 87249259Sdimvoid BasicBlock::setParent(Function *parent) { 88249259Sdim // Set Parent=parent, updating instruction symtab entries as appropriate. 89249259Sdim InstList.setSymTabObject(&Parent, parent); 90249259Sdim} 91249259Sdim 92341825Sdimiterator_range<filter_iterator<BasicBlock::const_iterator, 93341825Sdim std::function<bool(const Instruction &)>>> 94341825SdimBasicBlock::instructionsWithoutDebug() const { 95341825Sdim std::function<bool(const Instruction &)> Fn = [](const Instruction &I) { 96341825Sdim return !isa<DbgInfoIntrinsic>(I); 97341825Sdim }; 98341825Sdim return make_filter_range(*this, Fn); 99341825Sdim} 100341825Sdim 101341825Sdimiterator_range<filter_iterator<BasicBlock::iterator, 102341825Sdim std::function<bool(Instruction &)>>> 103341825SdimBasicBlock::instructionsWithoutDebug() { 104341825Sdim std::function<bool(Instruction &)> Fn = [](Instruction &I) { 105341825Sdim return !isa<DbgInfoIntrinsic>(I); 106341825Sdim }; 107341825Sdim return make_filter_range(*this, Fn); 108341825Sdim} 109341825Sdim 110360784Sdimfilter_iterator<BasicBlock::const_iterator, 111360784Sdim std::function<bool(const Instruction &)>>::difference_type 112360784SdimBasicBlock::sizeWithoutDebug() const { 113360784Sdim return std::distance(instructionsWithoutDebug().begin(), 114360784Sdim instructionsWithoutDebug().end()); 115360784Sdim} 116360784Sdim 117249259Sdimvoid BasicBlock::removeFromParent() { 118296417Sdim getParent()->getBasicBlockList().remove(getIterator()); 119249259Sdim} 120249259Sdim 121288943Sdimiplist<BasicBlock>::iterator BasicBlock::eraseFromParent() { 122296417Sdim return getParent()->getBasicBlockList().erase(getIterator()); 123249259Sdim} 124249259Sdim 125288943Sdim/// Unlink this basic block from its current function and 126249259Sdim/// insert it into the function that MovePos lives in, right before MovePos. 127249259Sdimvoid BasicBlock::moveBefore(BasicBlock *MovePos) { 128296417Sdim MovePos->getParent()->getBasicBlockList().splice( 129296417Sdim MovePos->getIterator(), getParent()->getBasicBlockList(), getIterator()); 130249259Sdim} 131249259Sdim 132288943Sdim/// Unlink this basic block from its current function and 133249259Sdim/// insert it into the function that MovePos lives in, right after MovePos. 134249259Sdimvoid BasicBlock::moveAfter(BasicBlock *MovePos) { 135296417Sdim MovePos->getParent()->getBasicBlockList().splice( 136296417Sdim ++MovePos->getIterator(), getParent()->getBasicBlockList(), 137296417Sdim getIterator()); 138249259Sdim} 139249259Sdim 140288943Sdimconst Module *BasicBlock::getModule() const { 141288943Sdim return getParent()->getParent(); 142288943Sdim} 143249259Sdim 144344779Sdimconst Instruction *BasicBlock::getTerminator() const { 145344779Sdim if (InstList.empty() || !InstList.back().isTerminator()) 146344779Sdim return nullptr; 147344779Sdim return &InstList.back(); 148249259Sdim} 149249259Sdim 150321369Sdimconst CallInst *BasicBlock::getTerminatingMustTailCall() const { 151280031Sdim if (InstList.empty()) 152280031Sdim return nullptr; 153321369Sdim const ReturnInst *RI = dyn_cast<ReturnInst>(&InstList.back()); 154280031Sdim if (!RI || RI == &InstList.front()) 155280031Sdim return nullptr; 156280031Sdim 157321369Sdim const Instruction *Prev = RI->getPrevNode(); 158280031Sdim if (!Prev) 159280031Sdim return nullptr; 160280031Sdim 161280031Sdim if (Value *RV = RI->getReturnValue()) { 162280031Sdim if (RV != Prev) 163280031Sdim return nullptr; 164280031Sdim 165280031Sdim // Look through the optional bitcast. 166280031Sdim if (auto *BI = dyn_cast<BitCastInst>(Prev)) { 167280031Sdim RV = BI->getOperand(0); 168280031Sdim Prev = BI->getPrevNode(); 169280031Sdim if (!Prev || RV != Prev) 170280031Sdim return nullptr; 171280031Sdim } 172280031Sdim } 173280031Sdim 174280031Sdim if (auto *CI = dyn_cast<CallInst>(Prev)) { 175280031Sdim if (CI->isMustTailCall()) 176280031Sdim return CI; 177280031Sdim } 178280031Sdim return nullptr; 179280031Sdim} 180280031Sdim 181321369Sdimconst CallInst *BasicBlock::getTerminatingDeoptimizeCall() const { 182309124Sdim if (InstList.empty()) 183309124Sdim return nullptr; 184309124Sdim auto *RI = dyn_cast<ReturnInst>(&InstList.back()); 185309124Sdim if (!RI || RI == &InstList.front()) 186309124Sdim return nullptr; 187309124Sdim 188309124Sdim if (auto *CI = dyn_cast_or_null<CallInst>(RI->getPrevNode())) 189309124Sdim if (Function *F = CI->getCalledFunction()) 190309124Sdim if (F->getIntrinsicID() == Intrinsic::experimental_deoptimize) 191309124Sdim return CI; 192309124Sdim 193309124Sdim return nullptr; 194309124Sdim} 195309124Sdim 196321369Sdimconst Instruction* BasicBlock::getFirstNonPHI() const { 197321369Sdim for (const Instruction &I : *this) 198288943Sdim if (!isa<PHINode>(I)) 199288943Sdim return &I; 200288943Sdim return nullptr; 201249259Sdim} 202249259Sdim 203321369Sdimconst Instruction* BasicBlock::getFirstNonPHIOrDbg() const { 204321369Sdim for (const Instruction &I : *this) 205288943Sdim if (!isa<PHINode>(I) && !isa<DbgInfoIntrinsic>(I)) 206288943Sdim return &I; 207288943Sdim return nullptr; 208249259Sdim} 209249259Sdim 210321369Sdimconst Instruction* BasicBlock::getFirstNonPHIOrDbgOrLifetime() const { 211321369Sdim for (const Instruction &I : *this) { 212288943Sdim if (isa<PHINode>(I) || isa<DbgInfoIntrinsic>(I)) 213249259Sdim continue; 214249259Sdim 215344779Sdim if (I.isLifetimeStartOrEnd()) 216344779Sdim continue; 217288943Sdim 218288943Sdim return &I; 219249259Sdim } 220288943Sdim return nullptr; 221249259Sdim} 222249259Sdim 223321369SdimBasicBlock::const_iterator BasicBlock::getFirstInsertionPt() const { 224321369Sdim const Instruction *FirstNonPHI = getFirstNonPHI(); 225288943Sdim if (!FirstNonPHI) 226288943Sdim return end(); 227288943Sdim 228321369Sdim const_iterator InsertPt = FirstNonPHI->getIterator(); 229296417Sdim if (InsertPt->isEHPad()) ++InsertPt; 230249259Sdim return InsertPt; 231249259Sdim} 232249259Sdim 233249259Sdimvoid BasicBlock::dropAllReferences() { 234309124Sdim for (Instruction &I : *this) 235309124Sdim I.dropAllReferences(); 236249259Sdim} 237249259Sdim 238288943Sdim/// If this basic block has a single predecessor block, 239249259Sdim/// return the block, otherwise return a null pointer. 240321369Sdimconst BasicBlock *BasicBlock::getSinglePredecessor() const { 241321369Sdim const_pred_iterator PI = pred_begin(this), E = pred_end(this); 242276479Sdim if (PI == E) return nullptr; // No preds. 243321369Sdim const BasicBlock *ThePred = *PI; 244249259Sdim ++PI; 245276479Sdim return (PI == E) ? ThePred : nullptr /*multiple preds*/; 246249259Sdim} 247249259Sdim 248288943Sdim/// If this basic block has a unique predecessor block, 249249259Sdim/// return the block, otherwise return a null pointer. 250249259Sdim/// Note that unique predecessor doesn't mean single edge, there can be 251249259Sdim/// multiple edges from the unique predecessor to this block (for example 252249259Sdim/// a switch statement with multiple cases having the same destination). 253321369Sdimconst BasicBlock *BasicBlock::getUniquePredecessor() const { 254321369Sdim const_pred_iterator PI = pred_begin(this), E = pred_end(this); 255276479Sdim if (PI == E) return nullptr; // No preds. 256321369Sdim const BasicBlock *PredBB = *PI; 257249259Sdim ++PI; 258249259Sdim for (;PI != E; ++PI) { 259249259Sdim if (*PI != PredBB) 260276479Sdim return nullptr; 261249259Sdim // The same predecessor appears multiple times in the predecessor list. 262249259Sdim // This is OK. 263249259Sdim } 264249259Sdim return PredBB; 265249259Sdim} 266249259Sdim 267344779Sdimbool BasicBlock::hasNPredecessors(unsigned N) const { 268344779Sdim return hasNItems(pred_begin(this), pred_end(this), N); 269344779Sdim} 270344779Sdim 271344779Sdimbool BasicBlock::hasNPredecessorsOrMore(unsigned N) const { 272344779Sdim return hasNItemsOrMore(pred_begin(this), pred_end(this), N); 273344779Sdim} 274344779Sdim 275321369Sdimconst BasicBlock *BasicBlock::getSingleSuccessor() const { 276321369Sdim succ_const_iterator SI = succ_begin(this), E = succ_end(this); 277288943Sdim if (SI == E) return nullptr; // no successors 278321369Sdim const BasicBlock *TheSucc = *SI; 279288943Sdim ++SI; 280288943Sdim return (SI == E) ? TheSucc : nullptr /* multiple successors */; 281288943Sdim} 282288943Sdim 283321369Sdimconst BasicBlock *BasicBlock::getUniqueSuccessor() const { 284321369Sdim succ_const_iterator SI = succ_begin(this), E = succ_end(this); 285296417Sdim if (SI == E) return nullptr; // No successors 286321369Sdim const BasicBlock *SuccBB = *SI; 287288943Sdim ++SI; 288288943Sdim for (;SI != E; ++SI) { 289288943Sdim if (*SI != SuccBB) 290296417Sdim return nullptr; 291288943Sdim // The same successor appears multiple times in the successor list. 292288943Sdim // This is OK. 293288943Sdim } 294288943Sdim return SuccBB; 295288943Sdim} 296288943Sdim 297321369Sdimiterator_range<BasicBlock::phi_iterator> BasicBlock::phis() { 298327952Sdim PHINode *P = empty() ? nullptr : dyn_cast<PHINode>(&*begin()); 299327952Sdim return make_range<phi_iterator>(P, nullptr); 300321369Sdim} 301321369Sdim 302288943Sdim/// This method is used to notify a BasicBlock that the 303249259Sdim/// specified Predecessor of the block is no longer able to reach it. This is 304249259Sdim/// actually not used to update the Predecessor list, but is actually used to 305249259Sdim/// update the PHI nodes that reside in the block. Note that this should be 306249259Sdim/// called while the predecessor still refers to this block. 307249259Sdim/// 308249259Sdimvoid BasicBlock::removePredecessor(BasicBlock *Pred, 309353358Sdim bool KeepOneInputPHIs) { 310249259Sdim assert((hasNUsesOrMore(16)||// Reduce cost of this assertion for complex CFGs. 311249259Sdim find(pred_begin(this), pred_end(this), Pred) != pred_end(this)) && 312249259Sdim "removePredecessor: BB is not a predecessor!"); 313249259Sdim 314249259Sdim if (InstList.empty()) return; 315249259Sdim PHINode *APN = dyn_cast<PHINode>(&front()); 316249259Sdim if (!APN) return; // Quick exit. 317249259Sdim 318249259Sdim // If there are exactly two predecessors, then we want to nuke the PHI nodes 319249259Sdim // altogether. However, we cannot do this, if this in this case: 320249259Sdim // 321249259Sdim // Loop: 322249259Sdim // %x = phi [X, Loop] 323249259Sdim // %x2 = add %x, 1 ;; This would become %x2 = add %x2, 1 324249259Sdim // br Loop ;; %x2 does not dominate all uses 325249259Sdim // 326249259Sdim // This is because the PHI node input is actually taken from the predecessor 327249259Sdim // basic block. The only case this can happen is with a self loop, so we 328249259Sdim // check for this case explicitly now. 329249259Sdim // 330249259Sdim unsigned max_idx = APN->getNumIncomingValues(); 331249259Sdim assert(max_idx != 0 && "PHI Node in block with 0 predecessors!?!?!"); 332249259Sdim if (max_idx == 2) { 333249259Sdim BasicBlock *Other = APN->getIncomingBlock(APN->getIncomingBlock(0) == Pred); 334249259Sdim 335249259Sdim // Disable PHI elimination! 336249259Sdim if (this == Other) max_idx = 3; 337249259Sdim } 338249259Sdim 339249259Sdim // <= Two predecessors BEFORE I remove one? 340353358Sdim if (max_idx <= 2 && !KeepOneInputPHIs) { 341249259Sdim // Yup, loop through and nuke the PHI nodes 342249259Sdim while (PHINode *PN = dyn_cast<PHINode>(&front())) { 343249259Sdim // Remove the predecessor first. 344353358Sdim PN->removeIncomingValue(Pred, !KeepOneInputPHIs); 345249259Sdim 346249259Sdim // If the PHI _HAD_ two uses, replace PHI node with its now *single* value 347249259Sdim if (max_idx == 2) { 348249259Sdim if (PN->getIncomingValue(0) != PN) 349249259Sdim PN->replaceAllUsesWith(PN->getIncomingValue(0)); 350249259Sdim else 351249259Sdim // We are left with an infinite loop with no entries: kill the PHI. 352249259Sdim PN->replaceAllUsesWith(UndefValue::get(PN->getType())); 353249259Sdim getInstList().pop_front(); // Remove the PHI node 354249259Sdim } 355249259Sdim 356249259Sdim // If the PHI node already only had one entry, it got deleted by 357249259Sdim // removeIncomingValue. 358249259Sdim } 359249259Sdim } else { 360249259Sdim // Okay, now we know that we need to remove predecessor #pred_idx from all 361249259Sdim // PHI nodes. Iterate over each PHI node fixing them up 362249259Sdim PHINode *PN; 363249259Sdim for (iterator II = begin(); (PN = dyn_cast<PHINode>(II)); ) { 364249259Sdim ++II; 365249259Sdim PN->removeIncomingValue(Pred, false); 366249259Sdim // If all incoming values to the Phi are the same, we can replace the Phi 367249259Sdim // with that value. 368276479Sdim Value* PNV = nullptr; 369353358Sdim if (!KeepOneInputPHIs && (PNV = PN->hasConstantValue())) 370249259Sdim if (PNV != PN) { 371249259Sdim PN->replaceAllUsesWith(PNV); 372249259Sdim PN->eraseFromParent(); 373249259Sdim } 374249259Sdim } 375249259Sdim } 376249259Sdim} 377249259Sdim 378296417Sdimbool BasicBlock::canSplitPredecessors() const { 379296417Sdim const Instruction *FirstNonPHI = getFirstNonPHI(); 380296417Sdim if (isa<LandingPadInst>(FirstNonPHI)) 381296417Sdim return true; 382296417Sdim // This is perhaps a little conservative because constructs like 383296417Sdim // CleanupBlockInst are pretty easy to split. However, SplitBlockPredecessors 384296417Sdim // cannot handle such things just yet. 385296417Sdim if (FirstNonPHI->isEHPad()) 386296417Sdim return false; 387296417Sdim return true; 388296417Sdim} 389249259Sdim 390321369Sdimbool BasicBlock::isLegalToHoistInto() const { 391321369Sdim auto *Term = getTerminator(); 392321369Sdim // No terminator means the block is under construction. 393321369Sdim if (!Term) 394321369Sdim return true; 395321369Sdim 396321369Sdim // If the block has no successors, there can be no instructions to hoist. 397321369Sdim assert(Term->getNumSuccessors() > 0); 398321369Sdim 399321369Sdim // Instructions should not be hoisted across exception handling boundaries. 400344779Sdim return !Term->isExceptionalTerminator(); 401321369Sdim} 402321369Sdim 403288943Sdim/// This splits a basic block into two at the specified 404249259Sdim/// instruction. Note that all instructions BEFORE the specified iterator stay 405249259Sdim/// as part of the original basic block, an unconditional branch is added to 406249259Sdim/// the new BB, and the rest of the instructions in the BB are moved to the new 407249259Sdim/// BB, including the old terminator. This invalidates the iterator. 408249259Sdim/// 409249259Sdim/// Note that this only works on well formed basic blocks (must have a 410249259Sdim/// terminator), and 'I' must not be the end of instruction list (which would 411249259Sdim/// cause a degenerate basic block to be formed, having a terminator inside of 412249259Sdim/// the basic block). 413249259Sdim/// 414249259SdimBasicBlock *BasicBlock::splitBasicBlock(iterator I, const Twine &BBName) { 415249259Sdim assert(getTerminator() && "Can't use splitBasicBlock on degenerate BB!"); 416249259Sdim assert(I != InstList.end() && 417249259Sdim "Trying to get me to create degenerate basic block!"); 418249259Sdim 419309124Sdim BasicBlock *New = BasicBlock::Create(getContext(), BBName, getParent(), 420309124Sdim this->getNextNode()); 421249259Sdim 422288943Sdim // Save DebugLoc of split point before invalidating iterator. 423288943Sdim DebugLoc Loc = I->getDebugLoc(); 424249259Sdim // Move all of the specified instructions from the original basic block into 425249259Sdim // the new basic block. 426249259Sdim New->getInstList().splice(New->end(), this->getInstList(), I, end()); 427249259Sdim 428249259Sdim // Add a branch instruction to the newly formed basic block. 429288943Sdim BranchInst *BI = BranchInst::Create(New, this); 430288943Sdim BI->setDebugLoc(Loc); 431249259Sdim 432249259Sdim // Now we must loop through all of the successors of the New block (which 433249259Sdim // _were_ the successors of the 'this' block), and update any PHI nodes in 434249259Sdim // successors. If there were PHI nodes in the successors, then they need to 435353358Sdim // know that incoming branches will be from New, not from Old (this). 436249259Sdim // 437353358Sdim New->replaceSuccessorsPhiUsesWith(this, New); 438249259Sdim return New; 439249259Sdim} 440249259Sdim 441353358Sdimvoid BasicBlock::replacePhiUsesWith(BasicBlock *Old, BasicBlock *New) { 442353358Sdim // N.B. This might not be a complete BasicBlock, so don't assume 443353358Sdim // that it ends with a non-phi instruction. 444353358Sdim for (iterator II = begin(), IE = end(); II != IE; ++II) { 445353358Sdim PHINode *PN = dyn_cast<PHINode>(II); 446353358Sdim if (!PN) 447353358Sdim break; 448353358Sdim PN->replaceIncomingBlockWith(Old, New); 449353358Sdim } 450353358Sdim} 451353358Sdim 452353358Sdimvoid BasicBlock::replaceSuccessorsPhiUsesWith(BasicBlock *Old, 453353358Sdim BasicBlock *New) { 454344779Sdim Instruction *TI = getTerminator(); 455249259Sdim if (!TI) 456249259Sdim // Cope with being called on a BasicBlock that doesn't have a terminator 457249259Sdim // yet. Clang's CodeGenFunction::EmitReturnBlock() likes to do this. 458249259Sdim return; 459353358Sdim llvm::for_each(successors(TI), [Old, New](BasicBlock *Succ) { 460353358Sdim Succ->replacePhiUsesWith(Old, New); 461353358Sdim }); 462249259Sdim} 463249259Sdim 464353358Sdimvoid BasicBlock::replaceSuccessorsPhiUsesWith(BasicBlock *New) { 465353358Sdim this->replaceSuccessorsPhiUsesWith(this, New); 466353358Sdim} 467353358Sdim 468288943Sdim/// Return true if this basic block is a landing pad. I.e., it's 469249259Sdim/// the destination of the 'unwind' edge of an invoke instruction. 470249259Sdimbool BasicBlock::isLandingPad() const { 471249259Sdim return isa<LandingPadInst>(getFirstNonPHI()); 472249259Sdim} 473249259Sdim 474288943Sdim/// Return the landingpad instruction associated with the landing pad. 475249259Sdimconst LandingPadInst *BasicBlock::getLandingPadInst() const { 476249259Sdim return dyn_cast<LandingPadInst>(getFirstNonPHI()); 477249259Sdim} 478327952Sdim 479327952SdimOptional<uint64_t> BasicBlock::getIrrLoopHeaderWeight() const { 480344779Sdim const Instruction *TI = getTerminator(); 481327952Sdim if (MDNode *MDIrrLoopHeader = 482327952Sdim TI->getMetadata(LLVMContext::MD_irr_loop)) { 483327952Sdim MDString *MDName = cast<MDString>(MDIrrLoopHeader->getOperand(0)); 484327952Sdim if (MDName->getString().equals("loop_header_weight")) { 485327952Sdim auto *CI = mdconst::extract<ConstantInt>(MDIrrLoopHeader->getOperand(1)); 486327952Sdim return Optional<uint64_t>(CI->getValue().getZExtValue()); 487327952Sdim } 488327952Sdim } 489327952Sdim return Optional<uint64_t>(); 490327952Sdim} 491341825Sdim 492341825SdimBasicBlock::iterator llvm::skipDebugIntrinsics(BasicBlock::iterator It) { 493341825Sdim while (isa<DbgInfoIntrinsic>(It)) 494341825Sdim ++It; 495341825Sdim return It; 496341825Sdim} 497