| File: | src/gnu/usr.bin/clang/libLLVM/../../../llvm/llvm/include/llvm/Support/GenericDomTree.h |
| Warning: | line 494, column 12 Called C++ object pointer is null |
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| 1 | //===- LoopSimplify.cpp - Loop Canonicalization Pass ----------------------===// | ||||||
| 2 | // | ||||||
| 3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. | ||||||
| 4 | // See https://llvm.org/LICENSE.txt for license information. | ||||||
| 5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception | ||||||
| 6 | // | ||||||
| 7 | //===----------------------------------------------------------------------===// | ||||||
| 8 | // | ||||||
| 9 | // This pass performs several transformations to transform natural loops into a | ||||||
| 10 | // simpler form, which makes subsequent analyses and transformations simpler and | ||||||
| 11 | // more effective. | ||||||
| 12 | // | ||||||
| 13 | // Loop pre-header insertion guarantees that there is a single, non-critical | ||||||
| 14 | // entry edge from outside of the loop to the loop header. This simplifies a | ||||||
| 15 | // number of analyses and transformations, such as LICM. | ||||||
| 16 | // | ||||||
| 17 | // Loop exit-block insertion guarantees that all exit blocks from the loop | ||||||
| 18 | // (blocks which are outside of the loop that have predecessors inside of the | ||||||
| 19 | // loop) only have predecessors from inside of the loop (and are thus dominated | ||||||
| 20 | // by the loop header). This simplifies transformations such as store-sinking | ||||||
| 21 | // that are built into LICM. | ||||||
| 22 | // | ||||||
| 23 | // This pass also guarantees that loops will have exactly one backedge. | ||||||
| 24 | // | ||||||
| 25 | // Indirectbr instructions introduce several complications. If the loop | ||||||
| 26 | // contains or is entered by an indirectbr instruction, it may not be possible | ||||||
| 27 | // to transform the loop and make these guarantees. Client code should check | ||||||
| 28 | // that these conditions are true before relying on them. | ||||||
| 29 | // | ||||||
| 30 | // Similar complications arise from callbr instructions, particularly in | ||||||
| 31 | // asm-goto where blockaddress expressions are used. | ||||||
| 32 | // | ||||||
| 33 | // Note that the simplifycfg pass will clean up blocks which are split out but | ||||||
| 34 | // end up being unnecessary, so usage of this pass should not pessimize | ||||||
| 35 | // generated code. | ||||||
| 36 | // | ||||||
| 37 | // This pass obviously modifies the CFG, but updates loop information and | ||||||
| 38 | // dominator information. | ||||||
| 39 | // | ||||||
| 40 | //===----------------------------------------------------------------------===// | ||||||
| 41 | |||||||
| 42 | #include "llvm/Transforms/Utils/LoopSimplify.h" | ||||||
| 43 | #include "llvm/ADT/DepthFirstIterator.h" | ||||||
| 44 | #include "llvm/ADT/SetOperations.h" | ||||||
| 45 | #include "llvm/ADT/SetVector.h" | ||||||
| 46 | #include "llvm/ADT/SmallVector.h" | ||||||
| 47 | #include "llvm/ADT/Statistic.h" | ||||||
| 48 | #include "llvm/Analysis/AliasAnalysis.h" | ||||||
| 49 | #include "llvm/Analysis/AssumptionCache.h" | ||||||
| 50 | #include "llvm/Analysis/BasicAliasAnalysis.h" | ||||||
| 51 | #include "llvm/Analysis/BranchProbabilityInfo.h" | ||||||
| 52 | #include "llvm/Analysis/DependenceAnalysis.h" | ||||||
| 53 | #include "llvm/Analysis/GlobalsModRef.h" | ||||||
| 54 | #include "llvm/Analysis/InstructionSimplify.h" | ||||||
| 55 | #include "llvm/Analysis/LoopInfo.h" | ||||||
| 56 | #include "llvm/Analysis/MemorySSA.h" | ||||||
| 57 | #include "llvm/Analysis/MemorySSAUpdater.h" | ||||||
| 58 | #include "llvm/Analysis/ScalarEvolution.h" | ||||||
| 59 | #include "llvm/Analysis/ScalarEvolutionAliasAnalysis.h" | ||||||
| 60 | #include "llvm/IR/CFG.h" | ||||||
| 61 | #include "llvm/IR/Constants.h" | ||||||
| 62 | #include "llvm/IR/DataLayout.h" | ||||||
| 63 | #include "llvm/IR/Dominators.h" | ||||||
| 64 | #include "llvm/IR/Function.h" | ||||||
| 65 | #include "llvm/IR/Instructions.h" | ||||||
| 66 | #include "llvm/IR/IntrinsicInst.h" | ||||||
| 67 | #include "llvm/IR/LLVMContext.h" | ||||||
| 68 | #include "llvm/IR/Module.h" | ||||||
| 69 | #include "llvm/IR/Type.h" | ||||||
| 70 | #include "llvm/InitializePasses.h" | ||||||
| 71 | #include "llvm/Support/Debug.h" | ||||||
| 72 | #include "llvm/Support/raw_ostream.h" | ||||||
| 73 | #include "llvm/Transforms/Utils.h" | ||||||
| 74 | #include "llvm/Transforms/Utils/BasicBlockUtils.h" | ||||||
| 75 | #include "llvm/Transforms/Utils/Local.h" | ||||||
| 76 | #include "llvm/Transforms/Utils/LoopUtils.h" | ||||||
| 77 | using namespace llvm; | ||||||
| 78 | |||||||
| 79 | #define DEBUG_TYPE"loop-simplify" "loop-simplify" | ||||||
| 80 | |||||||
| 81 | STATISTIC(NumNested , "Number of nested loops split out")static llvm::Statistic NumNested = {"loop-simplify", "NumNested" , "Number of nested loops split out"}; | ||||||
| 82 | |||||||
| 83 | // If the block isn't already, move the new block to right after some 'outside | ||||||
| 84 | // block' block. This prevents the preheader from being placed inside the loop | ||||||
| 85 | // body, e.g. when the loop hasn't been rotated. | ||||||
| 86 | static void placeSplitBlockCarefully(BasicBlock *NewBB, | ||||||
| 87 | SmallVectorImpl<BasicBlock *> &SplitPreds, | ||||||
| 88 | Loop *L) { | ||||||
| 89 | // Check to see if NewBB is already well placed. | ||||||
| 90 | Function::iterator BBI = --NewBB->getIterator(); | ||||||
| 91 | for (unsigned i = 0, e = SplitPreds.size(); i != e; ++i) { | ||||||
| 92 | if (&*BBI == SplitPreds[i]) | ||||||
| 93 | return; | ||||||
| 94 | } | ||||||
| 95 | |||||||
| 96 | // If it isn't already after an outside block, move it after one. This is | ||||||
| 97 | // always good as it makes the uncond branch from the outside block into a | ||||||
| 98 | // fall-through. | ||||||
| 99 | |||||||
| 100 | // Figure out *which* outside block to put this after. Prefer an outside | ||||||
| 101 | // block that neighbors a BB actually in the loop. | ||||||
| 102 | BasicBlock *FoundBB = nullptr; | ||||||
| 103 | for (unsigned i = 0, e = SplitPreds.size(); i != e; ++i) { | ||||||
| 104 | Function::iterator BBI = SplitPreds[i]->getIterator(); | ||||||
| 105 | if (++BBI != NewBB->getParent()->end() && L->contains(&*BBI)) { | ||||||
| 106 | FoundBB = SplitPreds[i]; | ||||||
| 107 | break; | ||||||
| 108 | } | ||||||
| 109 | } | ||||||
| 110 | |||||||
| 111 | // If our heuristic for a *good* bb to place this after doesn't find | ||||||
| 112 | // anything, just pick something. It's likely better than leaving it within | ||||||
| 113 | // the loop. | ||||||
| 114 | if (!FoundBB) | ||||||
| 115 | FoundBB = SplitPreds[0]; | ||||||
| 116 | NewBB->moveAfter(FoundBB); | ||||||
| 117 | } | ||||||
| 118 | |||||||
| 119 | /// InsertPreheaderForLoop - Once we discover that a loop doesn't have a | ||||||
| 120 | /// preheader, this method is called to insert one. This method has two phases: | ||||||
| 121 | /// preheader insertion and analysis updating. | ||||||
| 122 | /// | ||||||
| 123 | BasicBlock *llvm::InsertPreheaderForLoop(Loop *L, DominatorTree *DT, | ||||||
| 124 | LoopInfo *LI, MemorySSAUpdater *MSSAU, | ||||||
| 125 | bool PreserveLCSSA) { | ||||||
| 126 | BasicBlock *Header = L->getHeader(); | ||||||
| 127 | |||||||
| 128 | // Compute the set of predecessors of the loop that are not in the loop. | ||||||
| 129 | SmallVector<BasicBlock*, 8> OutsideBlocks; | ||||||
| 130 | for (BasicBlock *P : predecessors(Header)) { | ||||||
| 131 | if (!L->contains(P)) { // Coming in from outside the loop? | ||||||
| 132 | // If the loop is branched to from an indirect terminator, we won't | ||||||
| 133 | // be able to fully transform the loop, because it prohibits | ||||||
| 134 | // edge splitting. | ||||||
| 135 | if (P->getTerminator()->isIndirectTerminator()) | ||||||
| 136 | return nullptr; | ||||||
| 137 | |||||||
| 138 | // Keep track of it. | ||||||
| 139 | OutsideBlocks.push_back(P); | ||||||
| 140 | } | ||||||
| 141 | } | ||||||
| 142 | |||||||
| 143 | // Split out the loop pre-header. | ||||||
| 144 | BasicBlock *PreheaderBB; | ||||||
| 145 | PreheaderBB = SplitBlockPredecessors(Header, OutsideBlocks, ".preheader", DT, | ||||||
| 146 | LI, MSSAU, PreserveLCSSA); | ||||||
| 147 | if (!PreheaderBB) | ||||||
| 148 | return nullptr; | ||||||
| 149 | |||||||
| 150 | LLVM_DEBUG(dbgs() << "LoopSimplify: Creating pre-header "do { } while (false) | ||||||
| 151 | << PreheaderBB->getName() << "\n")do { } while (false); | ||||||
| 152 | |||||||
| 153 | // Make sure that NewBB is put someplace intelligent, which doesn't mess up | ||||||
| 154 | // code layout too horribly. | ||||||
| 155 | placeSplitBlockCarefully(PreheaderBB, OutsideBlocks, L); | ||||||
| 156 | |||||||
| 157 | return PreheaderBB; | ||||||
| 158 | } | ||||||
| 159 | |||||||
| 160 | /// Add the specified block, and all of its predecessors, to the specified set, | ||||||
| 161 | /// if it's not already in there. Stop predecessor traversal when we reach | ||||||
| 162 | /// StopBlock. | ||||||
| 163 | static void addBlockAndPredsToSet(BasicBlock *InputBB, BasicBlock *StopBlock, | ||||||
| 164 | SmallPtrSetImpl<BasicBlock *> &Blocks) { | ||||||
| 165 | SmallVector<BasicBlock *, 8> Worklist; | ||||||
| 166 | Worklist.push_back(InputBB); | ||||||
| 167 | do { | ||||||
| 168 | BasicBlock *BB = Worklist.pop_back_val(); | ||||||
| 169 | if (Blocks.insert(BB).second && BB != StopBlock) | ||||||
| 170 | // If BB is not already processed and it is not a stop block then | ||||||
| 171 | // insert its predecessor in the work list | ||||||
| 172 | append_range(Worklist, predecessors(BB)); | ||||||
| 173 | } while (!Worklist.empty()); | ||||||
| 174 | } | ||||||
| 175 | |||||||
| 176 | /// The first part of loop-nestification is to find a PHI node that tells | ||||||
| 177 | /// us how to partition the loops. | ||||||
| 178 | static PHINode *findPHIToPartitionLoops(Loop *L, DominatorTree *DT, | ||||||
| 179 | AssumptionCache *AC) { | ||||||
| 180 | const DataLayout &DL = L->getHeader()->getModule()->getDataLayout(); | ||||||
| 181 | for (BasicBlock::iterator I = L->getHeader()->begin(); isa<PHINode>(I); ) { | ||||||
| 182 | PHINode *PN = cast<PHINode>(I); | ||||||
| 183 | ++I; | ||||||
| 184 | if (Value *V = SimplifyInstruction(PN, {DL, nullptr, DT, AC})) { | ||||||
| 185 | // This is a degenerate PHI already, don't modify it! | ||||||
| 186 | PN->replaceAllUsesWith(V); | ||||||
| 187 | PN->eraseFromParent(); | ||||||
| 188 | continue; | ||||||
| 189 | } | ||||||
| 190 | |||||||
| 191 | // Scan this PHI node looking for a use of the PHI node by itself. | ||||||
| 192 | for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i) | ||||||
| 193 | if (PN->getIncomingValue(i) == PN && | ||||||
| 194 | L->contains(PN->getIncomingBlock(i))) | ||||||
| 195 | // We found something tasty to remove. | ||||||
| 196 | return PN; | ||||||
| 197 | } | ||||||
| 198 | return nullptr; | ||||||
| 199 | } | ||||||
| 200 | |||||||
| 201 | /// If this loop has multiple backedges, try to pull one of them out into | ||||||
| 202 | /// a nested loop. | ||||||
| 203 | /// | ||||||
| 204 | /// This is important for code that looks like | ||||||
| 205 | /// this: | ||||||
| 206 | /// | ||||||
| 207 | /// Loop: | ||||||
| 208 | /// ... | ||||||
| 209 | /// br cond, Loop, Next | ||||||
| 210 | /// ... | ||||||
| 211 | /// br cond2, Loop, Out | ||||||
| 212 | /// | ||||||
| 213 | /// To identify this common case, we look at the PHI nodes in the header of the | ||||||
| 214 | /// loop. PHI nodes with unchanging values on one backedge correspond to values | ||||||
| 215 | /// that change in the "outer" loop, but not in the "inner" loop. | ||||||
| 216 | /// | ||||||
| 217 | /// If we are able to separate out a loop, return the new outer loop that was | ||||||
| 218 | /// created. | ||||||
| 219 | /// | ||||||
| 220 | static Loop *separateNestedLoop(Loop *L, BasicBlock *Preheader, | ||||||
| 221 | DominatorTree *DT, LoopInfo *LI, | ||||||
| 222 | ScalarEvolution *SE, bool PreserveLCSSA, | ||||||
| 223 | AssumptionCache *AC, MemorySSAUpdater *MSSAU) { | ||||||
| 224 | // Don't try to separate loops without a preheader. | ||||||
| 225 | if (!Preheader) | ||||||
| 226 | return nullptr; | ||||||
| 227 | |||||||
| 228 | // Treat the presence of convergent functions conservatively. The | ||||||
| 229 | // transformation is invalid if calls to certain convergent | ||||||
| 230 | // functions (like an AMDGPU barrier) get included in the resulting | ||||||
| 231 | // inner loop. But blocks meant for the inner loop will be | ||||||
| 232 | // identified later at a point where it's too late to abort the | ||||||
| 233 | // transformation. Also, the convergent attribute is not really | ||||||
| 234 | // sufficient to express the semantics of functions that are | ||||||
| 235 | // affected by this transformation. So we choose to back off if such | ||||||
| 236 | // a function call is present until a better alternative becomes | ||||||
| 237 | // available. This is similar to the conservative treatment of | ||||||
| 238 | // convergent function calls in GVNHoist and JumpThreading. | ||||||
| 239 | for (auto BB : L->blocks()) { | ||||||
| 240 | for (auto &II : *BB) { | ||||||
| 241 | if (auto CI = dyn_cast<CallBase>(&II)) { | ||||||
| 242 | if (CI->isConvergent()) { | ||||||
| 243 | return nullptr; | ||||||
| 244 | } | ||||||
| 245 | } | ||||||
| 246 | } | ||||||
| 247 | } | ||||||
| 248 | |||||||
| 249 | // The header is not a landing pad; preheader insertion should ensure this. | ||||||
| 250 | BasicBlock *Header = L->getHeader(); | ||||||
| 251 | assert(!Header->isEHPad() && "Can't insert backedge to EH pad")((void)0); | ||||||
| 252 | |||||||
| 253 | PHINode *PN = findPHIToPartitionLoops(L, DT, AC); | ||||||
| 254 | if (!PN) return nullptr; // No known way to partition. | ||||||
| 255 | |||||||
| 256 | // Pull out all predecessors that have varying values in the loop. This | ||||||
| 257 | // handles the case when a PHI node has multiple instances of itself as | ||||||
| 258 | // arguments. | ||||||
| 259 | SmallVector<BasicBlock*, 8> OuterLoopPreds; | ||||||
| 260 | for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i) { | ||||||
| 261 | if (PN->getIncomingValue(i) != PN || | ||||||
| 262 | !L->contains(PN->getIncomingBlock(i))) { | ||||||
| 263 | // We can't split indirect control flow edges. | ||||||
| 264 | if (PN->getIncomingBlock(i)->getTerminator()->isIndirectTerminator()) | ||||||
| 265 | return nullptr; | ||||||
| 266 | OuterLoopPreds.push_back(PN->getIncomingBlock(i)); | ||||||
| 267 | } | ||||||
| 268 | } | ||||||
| 269 | LLVM_DEBUG(dbgs() << "LoopSimplify: Splitting out a new outer loop\n")do { } while (false); | ||||||
| 270 | |||||||
| 271 | // If ScalarEvolution is around and knows anything about values in | ||||||
| 272 | // this loop, tell it to forget them, because we're about to | ||||||
| 273 | // substantially change it. | ||||||
| 274 | if (SE) | ||||||
| 275 | SE->forgetLoop(L); | ||||||
| 276 | |||||||
| 277 | BasicBlock *NewBB = SplitBlockPredecessors(Header, OuterLoopPreds, ".outer", | ||||||
| 278 | DT, LI, MSSAU, PreserveLCSSA); | ||||||
| 279 | |||||||
| 280 | // Make sure that NewBB is put someplace intelligent, which doesn't mess up | ||||||
| 281 | // code layout too horribly. | ||||||
| 282 | placeSplitBlockCarefully(NewBB, OuterLoopPreds, L); | ||||||
| 283 | |||||||
| 284 | // Create the new outer loop. | ||||||
| 285 | Loop *NewOuter = LI->AllocateLoop(); | ||||||
| 286 | |||||||
| 287 | // Change the parent loop to use the outer loop as its child now. | ||||||
| 288 | if (Loop *Parent = L->getParentLoop()) | ||||||
| 289 | Parent->replaceChildLoopWith(L, NewOuter); | ||||||
| 290 | else | ||||||
| 291 | LI->changeTopLevelLoop(L, NewOuter); | ||||||
| 292 | |||||||
| 293 | // L is now a subloop of our outer loop. | ||||||
| 294 | NewOuter->addChildLoop(L); | ||||||
| 295 | |||||||
| 296 | for (Loop::block_iterator I = L->block_begin(), E = L->block_end(); | ||||||
| 297 | I != E; ++I) | ||||||
| 298 | NewOuter->addBlockEntry(*I); | ||||||
| 299 | |||||||
| 300 | // Now reset the header in L, which had been moved by | ||||||
| 301 | // SplitBlockPredecessors for the outer loop. | ||||||
| 302 | L->moveToHeader(Header); | ||||||
| 303 | |||||||
| 304 | // Determine which blocks should stay in L and which should be moved out to | ||||||
| 305 | // the Outer loop now. | ||||||
| 306 | SmallPtrSet<BasicBlock *, 4> BlocksInL; | ||||||
| 307 | for (BasicBlock *P : predecessors(Header)) { | ||||||
| 308 | if (DT->dominates(Header, P)) | ||||||
| 309 | addBlockAndPredsToSet(P, Header, BlocksInL); | ||||||
| 310 | } | ||||||
| 311 | |||||||
| 312 | // Scan all of the loop children of L, moving them to OuterLoop if they are | ||||||
| 313 | // not part of the inner loop. | ||||||
| 314 | const std::vector<Loop*> &SubLoops = L->getSubLoops(); | ||||||
| 315 | for (size_t I = 0; I != SubLoops.size(); ) | ||||||
| 316 | if (BlocksInL.count(SubLoops[I]->getHeader())) | ||||||
| 317 | ++I; // Loop remains in L | ||||||
| 318 | else | ||||||
| 319 | NewOuter->addChildLoop(L->removeChildLoop(SubLoops.begin() + I)); | ||||||
| 320 | |||||||
| 321 | SmallVector<BasicBlock *, 8> OuterLoopBlocks; | ||||||
| 322 | OuterLoopBlocks.push_back(NewBB); | ||||||
| 323 | // Now that we know which blocks are in L and which need to be moved to | ||||||
| 324 | // OuterLoop, move any blocks that need it. | ||||||
| 325 | for (unsigned i = 0; i != L->getBlocks().size(); ++i) { | ||||||
| 326 | BasicBlock *BB = L->getBlocks()[i]; | ||||||
| 327 | if (!BlocksInL.count(BB)) { | ||||||
| 328 | // Move this block to the parent, updating the exit blocks sets | ||||||
| 329 | L->removeBlockFromLoop(BB); | ||||||
| 330 | if ((*LI)[BB] == L) { | ||||||
| 331 | LI->changeLoopFor(BB, NewOuter); | ||||||
| 332 | OuterLoopBlocks.push_back(BB); | ||||||
| 333 | } | ||||||
| 334 | --i; | ||||||
| 335 | } | ||||||
| 336 | } | ||||||
| 337 | |||||||
| 338 | // Split edges to exit blocks from the inner loop, if they emerged in the | ||||||
| 339 | // process of separating the outer one. | ||||||
| 340 | formDedicatedExitBlocks(L, DT, LI, MSSAU, PreserveLCSSA); | ||||||
| 341 | |||||||
| 342 | if (PreserveLCSSA) { | ||||||
| 343 | // Fix LCSSA form for L. Some values, which previously were only used inside | ||||||
| 344 | // L, can now be used in NewOuter loop. We need to insert phi-nodes for them | ||||||
| 345 | // in corresponding exit blocks. | ||||||
| 346 | // We don't need to form LCSSA recursively, because there cannot be uses | ||||||
| 347 | // inside a newly created loop of defs from inner loops as those would | ||||||
| 348 | // already be a use of an LCSSA phi node. | ||||||
| 349 | formLCSSA(*L, *DT, LI, SE); | ||||||
| 350 | |||||||
| 351 | assert(NewOuter->isRecursivelyLCSSAForm(*DT, *LI) &&((void)0) | ||||||
| 352 | "LCSSA is broken after separating nested loops!")((void)0); | ||||||
| 353 | } | ||||||
| 354 | |||||||
| 355 | return NewOuter; | ||||||
| 356 | } | ||||||
| 357 | |||||||
| 358 | /// This method is called when the specified loop has more than one | ||||||
| 359 | /// backedge in it. | ||||||
| 360 | /// | ||||||
| 361 | /// If this occurs, revector all of these backedges to target a new basic block | ||||||
| 362 | /// and have that block branch to the loop header. This ensures that loops | ||||||
| 363 | /// have exactly one backedge. | ||||||
| 364 | static BasicBlock *insertUniqueBackedgeBlock(Loop *L, BasicBlock *Preheader, | ||||||
| 365 | DominatorTree *DT, LoopInfo *LI, | ||||||
| 366 | MemorySSAUpdater *MSSAU) { | ||||||
| 367 | assert(L->getNumBackEdges() > 1 && "Must have > 1 backedge!")((void)0); | ||||||
| 368 | |||||||
| 369 | // Get information about the loop | ||||||
| 370 | BasicBlock *Header = L->getHeader(); | ||||||
| 371 | Function *F = Header->getParent(); | ||||||
| 372 | |||||||
| 373 | // Unique backedge insertion currently depends on having a preheader. | ||||||
| 374 | if (!Preheader
| ||||||
| 375 | return nullptr; | ||||||
| 376 | |||||||
| 377 | // The header is not an EH pad; preheader insertion should ensure this. | ||||||
| 378 | assert(!Header->isEHPad() && "Can't insert backedge to EH pad")((void)0); | ||||||
| 379 | |||||||
| 380 | // Figure out which basic blocks contain back-edges to the loop header. | ||||||
| 381 | std::vector<BasicBlock*> BackedgeBlocks; | ||||||
| 382 | for (BasicBlock *P : predecessors(Header)) { | ||||||
| 383 | // Indirect edges cannot be split, so we must fail if we find one. | ||||||
| 384 | if (P->getTerminator()->isIndirectTerminator()) | ||||||
| 385 | return nullptr; | ||||||
| 386 | |||||||
| 387 | if (P != Preheader) BackedgeBlocks.push_back(P); | ||||||
| 388 | } | ||||||
| 389 | |||||||
| 390 | // Create and insert the new backedge block... | ||||||
| 391 | BasicBlock *BEBlock = BasicBlock::Create(Header->getContext(), | ||||||
| 392 | Header->getName() + ".backedge", F); | ||||||
| 393 | BranchInst *BETerminator = BranchInst::Create(Header, BEBlock); | ||||||
| 394 | BETerminator->setDebugLoc(Header->getFirstNonPHI()->getDebugLoc()); | ||||||
| 395 | |||||||
| 396 | LLVM_DEBUG(dbgs() << "LoopSimplify: Inserting unique backedge block "do { } while (false) | ||||||
| 397 | << BEBlock->getName() << "\n")do { } while (false); | ||||||
| 398 | |||||||
| 399 | // Move the new backedge block to right after the last backedge block. | ||||||
| 400 | Function::iterator InsertPos = ++BackedgeBlocks.back()->getIterator(); | ||||||
| 401 | F->getBasicBlockList().splice(InsertPos, F->getBasicBlockList(), BEBlock); | ||||||
| 402 | |||||||
| 403 | // Now that the block has been inserted into the function, create PHI nodes in | ||||||
| 404 | // the backedge block which correspond to any PHI nodes in the header block. | ||||||
| 405 | for (BasicBlock::iterator I = Header->begin(); isa<PHINode>(I); ++I) { | ||||||
| 406 | PHINode *PN = cast<PHINode>(I); | ||||||
| 407 | PHINode *NewPN = PHINode::Create(PN->getType(), BackedgeBlocks.size(), | ||||||
| 408 | PN->getName()+".be", BETerminator); | ||||||
| 409 | |||||||
| 410 | // Loop over the PHI node, moving all entries except the one for the | ||||||
| 411 | // preheader over to the new PHI node. | ||||||
| 412 | unsigned PreheaderIdx = ~0U; | ||||||
| 413 | bool HasUniqueIncomingValue = true; | ||||||
| 414 | Value *UniqueValue = nullptr; | ||||||
| 415 | for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i) { | ||||||
| 416 | BasicBlock *IBB = PN->getIncomingBlock(i); | ||||||
| 417 | Value *IV = PN->getIncomingValue(i); | ||||||
| 418 | if (IBB == Preheader) { | ||||||
| 419 | PreheaderIdx = i; | ||||||
| 420 | } else { | ||||||
| 421 | NewPN->addIncoming(IV, IBB); | ||||||
| 422 | if (HasUniqueIncomingValue) { | ||||||
| 423 | if (!UniqueValue) | ||||||
| 424 | UniqueValue = IV; | ||||||
| 425 | else if (UniqueValue != IV) | ||||||
| 426 | HasUniqueIncomingValue = false; | ||||||
| 427 | } | ||||||
| 428 | } | ||||||
| 429 | } | ||||||
| 430 | |||||||
| 431 | // Delete all of the incoming values from the old PN except the preheader's | ||||||
| 432 | assert(PreheaderIdx != ~0U && "PHI has no preheader entry??")((void)0); | ||||||
| 433 | if (PreheaderIdx != 0) { | ||||||
| 434 | PN->setIncomingValue(0, PN->getIncomingValue(PreheaderIdx)); | ||||||
| 435 | PN->setIncomingBlock(0, PN->getIncomingBlock(PreheaderIdx)); | ||||||
| 436 | } | ||||||
| 437 | // Nuke all entries except the zero'th. | ||||||
| 438 | for (unsigned i = 0, e = PN->getNumIncomingValues()-1; i != e; ++i) | ||||||
| 439 | PN->removeIncomingValue(e-i, false); | ||||||
| 440 | |||||||
| 441 | // Finally, add the newly constructed PHI node as the entry for the BEBlock. | ||||||
| 442 | PN->addIncoming(NewPN, BEBlock); | ||||||
| 443 | |||||||
| 444 | // As an optimization, if all incoming values in the new PhiNode (which is a | ||||||
| 445 | // subset of the incoming values of the old PHI node) have the same value, | ||||||
| 446 | // eliminate the PHI Node. | ||||||
| 447 | if (HasUniqueIncomingValue) { | ||||||
| 448 | NewPN->replaceAllUsesWith(UniqueValue); | ||||||
| 449 | BEBlock->getInstList().erase(NewPN); | ||||||
| 450 | } | ||||||
| 451 | } | ||||||
| 452 | |||||||
| 453 | // Now that all of the PHI nodes have been inserted and adjusted, modify the | ||||||
| 454 | // backedge blocks to jump to the BEBlock instead of the header. | ||||||
| 455 | // If one of the backedges has llvm.loop metadata attached, we remove | ||||||
| 456 | // it from the backedge and add it to BEBlock. | ||||||
| 457 | unsigned LoopMDKind = BEBlock->getContext().getMDKindID("llvm.loop"); | ||||||
| 458 | MDNode *LoopMD = nullptr; | ||||||
| 459 | for (unsigned i = 0, e = BackedgeBlocks.size(); i != e; ++i) { | ||||||
| 460 | Instruction *TI = BackedgeBlocks[i]->getTerminator(); | ||||||
| 461 | if (!LoopMD) | ||||||
| 462 | LoopMD = TI->getMetadata(LoopMDKind); | ||||||
| 463 | TI->setMetadata(LoopMDKind, nullptr); | ||||||
| 464 | TI->replaceSuccessorWith(Header, BEBlock); | ||||||
| 465 | } | ||||||
| 466 | BEBlock->getTerminator()->setMetadata(LoopMDKind, LoopMD); | ||||||
| 467 | |||||||
| 468 | //===--- Update all analyses which we must preserve now -----------------===// | ||||||
| 469 | |||||||
| 470 | // Update Loop Information - we know that this block is now in the current | ||||||
| 471 | // loop and all parent loops. | ||||||
| 472 | L->addBasicBlockToLoop(BEBlock, *LI); | ||||||
| 473 | |||||||
| 474 | // Update dominator information | ||||||
| 475 | DT->splitBlock(BEBlock); | ||||||
| 476 | |||||||
| 477 | if (MSSAU) | ||||||
| 478 | MSSAU->updatePhisWhenInsertingUniqueBackedgeBlock(Header, Preheader, | ||||||
| 479 | BEBlock); | ||||||
| 480 | |||||||
| 481 | return BEBlock; | ||||||
| 482 | } | ||||||
| 483 | |||||||
| 484 | /// Simplify one loop and queue further loops for simplification. | ||||||
| 485 | static bool simplifyOneLoop(Loop *L, SmallVectorImpl<Loop *> &Worklist, | ||||||
| 486 | DominatorTree *DT, LoopInfo *LI, | ||||||
| 487 | ScalarEvolution *SE, AssumptionCache *AC, | ||||||
| 488 | MemorySSAUpdater *MSSAU, bool PreserveLCSSA) { | ||||||
| 489 | bool Changed = false; | ||||||
| 490 | if (MSSAU && VerifyMemorySSA) | ||||||
| |||||||
| 491 | MSSAU->getMemorySSA()->verifyMemorySSA(); | ||||||
| 492 | |||||||
| 493 | ReprocessLoop: | ||||||
| 494 | |||||||
| 495 | // Check to see that no blocks (other than the header) in this loop have | ||||||
| 496 | // predecessors that are not in the loop. This is not valid for natural | ||||||
| 497 | // loops, but can occur if the blocks are unreachable. Since they are | ||||||
| 498 | // unreachable we can just shamelessly delete those CFG edges! | ||||||
| 499 | for (Loop::block_iterator BB = L->block_begin(), E = L->block_end(); | ||||||
| 500 | BB != E; ++BB) { | ||||||
| 501 | if (*BB == L->getHeader()) continue; | ||||||
| 502 | |||||||
| 503 | SmallPtrSet<BasicBlock*, 4> BadPreds; | ||||||
| 504 | for (BasicBlock *P : predecessors(*BB)) | ||||||
| 505 | if (!L->contains(P)) | ||||||
| 506 | BadPreds.insert(P); | ||||||
| 507 | |||||||
| 508 | // Delete each unique out-of-loop (and thus dead) predecessor. | ||||||
| 509 | for (BasicBlock *P : BadPreds) { | ||||||
| 510 | |||||||
| 511 | LLVM_DEBUG(dbgs() << "LoopSimplify: Deleting edge from dead predecessor "do { } while (false) | ||||||
| 512 | << P->getName() << "\n")do { } while (false); | ||||||
| 513 | |||||||
| 514 | // Zap the dead pred's terminator and replace it with unreachable. | ||||||
| 515 | Instruction *TI = P->getTerminator(); | ||||||
| 516 | changeToUnreachable(TI, PreserveLCSSA, | ||||||
| 517 | /*DTU=*/nullptr, MSSAU); | ||||||
| 518 | Changed = true; | ||||||
| 519 | } | ||||||
| 520 | } | ||||||
| 521 | |||||||
| 522 | if (MSSAU
| ||||||
| 523 | MSSAU->getMemorySSA()->verifyMemorySSA(); | ||||||
| 524 | |||||||
| 525 | // If there are exiting blocks with branches on undef, resolve the undef in | ||||||
| 526 | // the direction which will exit the loop. This will help simplify loop | ||||||
| 527 | // trip count computations. | ||||||
| 528 | SmallVector<BasicBlock*, 8> ExitingBlocks; | ||||||
| 529 | L->getExitingBlocks(ExitingBlocks); | ||||||
| 530 | for (BasicBlock *ExitingBlock : ExitingBlocks) | ||||||
| 531 | if (BranchInst *BI = dyn_cast<BranchInst>(ExitingBlock->getTerminator())) | ||||||
| 532 | if (BI->isConditional()) { | ||||||
| 533 | if (UndefValue *Cond = dyn_cast<UndefValue>(BI->getCondition())) { | ||||||
| 534 | |||||||
| 535 | LLVM_DEBUG(dbgs()do { } while (false) | ||||||
| 536 | << "LoopSimplify: Resolving \"br i1 undef\" to exit in "do { } while (false) | ||||||
| 537 | << ExitingBlock->getName() << "\n")do { } while (false); | ||||||
| 538 | |||||||
| 539 | BI->setCondition(ConstantInt::get(Cond->getType(), | ||||||
| 540 | !L->contains(BI->getSuccessor(0)))); | ||||||
| 541 | |||||||
| 542 | Changed = true; | ||||||
| 543 | } | ||||||
| 544 | } | ||||||
| 545 | |||||||
| 546 | // Does the loop already have a preheader? If so, don't insert one. | ||||||
| 547 | BasicBlock *Preheader = L->getLoopPreheader(); | ||||||
| 548 | if (!Preheader) { | ||||||
| 549 | Preheader = InsertPreheaderForLoop(L, DT, LI, MSSAU, PreserveLCSSA); | ||||||
| 550 | if (Preheader) | ||||||
| 551 | Changed = true; | ||||||
| 552 | } | ||||||
| 553 | |||||||
| 554 | // Next, check to make sure that all exit nodes of the loop only have | ||||||
| 555 | // predecessors that are inside of the loop. This check guarantees that the | ||||||
| 556 | // loop preheader/header will dominate the exit blocks. If the exit block has | ||||||
| 557 | // predecessors from outside of the loop, split the edge now. | ||||||
| 558 | if (formDedicatedExitBlocks(L, DT, LI, MSSAU, PreserveLCSSA)) | ||||||
| 559 | Changed = true; | ||||||
| 560 | |||||||
| 561 | if (MSSAU
| ||||||
| 562 | MSSAU->getMemorySSA()->verifyMemorySSA(); | ||||||
| 563 | |||||||
| 564 | // If the header has more than two predecessors at this point (from the | ||||||
| 565 | // preheader and from multiple backedges), we must adjust the loop. | ||||||
| 566 | BasicBlock *LoopLatch = L->getLoopLatch(); | ||||||
| 567 | if (!LoopLatch) { | ||||||
| 568 | // If this is really a nested loop, rip it out into a child loop. Don't do | ||||||
| 569 | // this for loops with a giant number of backedges, just factor them into a | ||||||
| 570 | // common backedge instead. | ||||||
| 571 | if (L->getNumBackEdges() < 8) { | ||||||
| 572 | if (Loop *OuterL = separateNestedLoop(L, Preheader, DT, LI, SE, | ||||||
| 573 | PreserveLCSSA, AC, MSSAU)) { | ||||||
| 574 | ++NumNested; | ||||||
| 575 | // Enqueue the outer loop as it should be processed next in our | ||||||
| 576 | // depth-first nest walk. | ||||||
| 577 | Worklist.push_back(OuterL); | ||||||
| 578 | |||||||
| 579 | // This is a big restructuring change, reprocess the whole loop. | ||||||
| 580 | Changed = true; | ||||||
| 581 | // GCC doesn't tail recursion eliminate this. | ||||||
| 582 | // FIXME: It isn't clear we can't rely on LLVM to TRE this. | ||||||
| 583 | goto ReprocessLoop; | ||||||
| 584 | } | ||||||
| 585 | } | ||||||
| 586 | |||||||
| 587 | // If we either couldn't, or didn't want to, identify nesting of the loops, | ||||||
| 588 | // insert a new block that all backedges target, then make it jump to the | ||||||
| 589 | // loop header. | ||||||
| 590 | LoopLatch = insertUniqueBackedgeBlock(L, Preheader, DT, LI, MSSAU); | ||||||
| 591 | if (LoopLatch) | ||||||
| 592 | Changed = true; | ||||||
| 593 | } | ||||||
| 594 | |||||||
| 595 | if (MSSAU && VerifyMemorySSA) | ||||||
| 596 | MSSAU->getMemorySSA()->verifyMemorySSA(); | ||||||
| 597 | |||||||
| 598 | const DataLayout &DL = L->getHeader()->getModule()->getDataLayout(); | ||||||
| 599 | |||||||
| 600 | // Scan over the PHI nodes in the loop header. Since they now have only two | ||||||
| 601 | // incoming values (the loop is canonicalized), we may have simplified the PHI | ||||||
| 602 | // down to 'X = phi [X, Y]', which should be replaced with 'Y'. | ||||||
| 603 | PHINode *PN; | ||||||
| 604 | for (BasicBlock::iterator I = L->getHeader()->begin(); | ||||||
| 605 | (PN = dyn_cast<PHINode>(I++)); ) | ||||||
| 606 | if (Value *V = SimplifyInstruction(PN, {DL, nullptr, DT, AC})) { | ||||||
| 607 | if (SE) SE->forgetValue(PN); | ||||||
| 608 | if (!PreserveLCSSA || LI->replacementPreservesLCSSAForm(PN, V)) { | ||||||
| 609 | PN->replaceAllUsesWith(V); | ||||||
| 610 | PN->eraseFromParent(); | ||||||
| 611 | Changed = true; | ||||||
| 612 | } | ||||||
| 613 | } | ||||||
| 614 | |||||||
| 615 | // If this loop has multiple exits and the exits all go to the same | ||||||
| 616 | // block, attempt to merge the exits. This helps several passes, such | ||||||
| 617 | // as LoopRotation, which do not support loops with multiple exits. | ||||||
| 618 | // SimplifyCFG also does this (and this code uses the same utility | ||||||
| 619 | // function), however this code is loop-aware, where SimplifyCFG is | ||||||
| 620 | // not. That gives it the advantage of being able to hoist | ||||||
| 621 | // loop-invariant instructions out of the way to open up more | ||||||
| 622 | // opportunities, and the disadvantage of having the responsibility | ||||||
| 623 | // to preserve dominator information. | ||||||
| 624 | auto HasUniqueExitBlock = [&]() { | ||||||
| 625 | BasicBlock *UniqueExit = nullptr; | ||||||
| 626 | for (auto *ExitingBB : ExitingBlocks) | ||||||
| 627 | for (auto *SuccBB : successors(ExitingBB)) { | ||||||
| 628 | if (L->contains(SuccBB)) | ||||||
| 629 | continue; | ||||||
| 630 | |||||||
| 631 | if (!UniqueExit) | ||||||
| 632 | UniqueExit = SuccBB; | ||||||
| 633 | else if (UniqueExit != SuccBB) | ||||||
| 634 | return false; | ||||||
| 635 | } | ||||||
| 636 | |||||||
| 637 | return true; | ||||||
| 638 | }; | ||||||
| 639 | if (HasUniqueExitBlock()) { | ||||||
| 640 | for (unsigned i = 0, e = ExitingBlocks.size(); i != e; ++i) { | ||||||
| 641 | BasicBlock *ExitingBlock = ExitingBlocks[i]; | ||||||
| 642 | if (!ExitingBlock->getSinglePredecessor()) continue; | ||||||
| 643 | BranchInst *BI = dyn_cast<BranchInst>(ExitingBlock->getTerminator()); | ||||||
| 644 | if (!BI || !BI->isConditional()) continue; | ||||||
| 645 | CmpInst *CI = dyn_cast<CmpInst>(BI->getCondition()); | ||||||
| 646 | if (!CI || CI->getParent() != ExitingBlock) continue; | ||||||
| 647 | |||||||
| 648 | // Attempt to hoist out all instructions except for the | ||||||
| 649 | // comparison and the branch. | ||||||
| 650 | bool AllInvariant = true; | ||||||
| 651 | bool AnyInvariant = false; | ||||||
| 652 | for (auto I = ExitingBlock->instructionsWithoutDebug().begin(); &*I != BI; ) { | ||||||
| 653 | Instruction *Inst = &*I++; | ||||||
| 654 | if (Inst == CI) | ||||||
| 655 | continue; | ||||||
| 656 | if (!L->makeLoopInvariant( | ||||||
| 657 | Inst, AnyInvariant, | ||||||
| 658 | Preheader ? Preheader->getTerminator() : nullptr, MSSAU)) { | ||||||
| 659 | AllInvariant = false; | ||||||
| 660 | break; | ||||||
| 661 | } | ||||||
| 662 | } | ||||||
| 663 | if (AnyInvariant) { | ||||||
| 664 | Changed = true; | ||||||
| 665 | // The loop disposition of all SCEV expressions that depend on any | ||||||
| 666 | // hoisted values have also changed. | ||||||
| 667 | if (SE) | ||||||
| 668 | SE->forgetLoopDispositions(L); | ||||||
| 669 | } | ||||||
| 670 | if (!AllInvariant) continue; | ||||||
| 671 | |||||||
| 672 | // The block has now been cleared of all instructions except for | ||||||
| 673 | // a comparison and a conditional branch. SimplifyCFG may be able | ||||||
| 674 | // to fold it now. | ||||||
| 675 | if (!FoldBranchToCommonDest(BI, /*DTU=*/nullptr, MSSAU)) | ||||||
| 676 | continue; | ||||||
| 677 | |||||||
| 678 | // Success. The block is now dead, so remove it from the loop, | ||||||
| 679 | // update the dominator tree and delete it. | ||||||
| 680 | LLVM_DEBUG(dbgs() << "LoopSimplify: Eliminating exiting block "do { } while (false) | ||||||
| 681 | << ExitingBlock->getName() << "\n")do { } while (false); | ||||||
| 682 | |||||||
| 683 | assert(pred_empty(ExitingBlock))((void)0); | ||||||
| 684 | Changed = true; | ||||||
| 685 | LI->removeBlock(ExitingBlock); | ||||||
| 686 | |||||||
| 687 | DomTreeNode *Node = DT->getNode(ExitingBlock); | ||||||
| 688 | while (!Node->isLeaf()) { | ||||||
| 689 | DomTreeNode *Child = Node->back(); | ||||||
| 690 | DT->changeImmediateDominator(Child, Node->getIDom()); | ||||||
| 691 | } | ||||||
| 692 | DT->eraseNode(ExitingBlock); | ||||||
| 693 | if (MSSAU) { | ||||||
| 694 | SmallSetVector<BasicBlock *, 8> ExitBlockSet; | ||||||
| 695 | ExitBlockSet.insert(ExitingBlock); | ||||||
| 696 | MSSAU->removeBlocks(ExitBlockSet); | ||||||
| 697 | } | ||||||
| 698 | |||||||
| 699 | BI->getSuccessor(0)->removePredecessor( | ||||||
| 700 | ExitingBlock, /* KeepOneInputPHIs */ PreserveLCSSA); | ||||||
| 701 | BI->getSuccessor(1)->removePredecessor( | ||||||
| 702 | ExitingBlock, /* KeepOneInputPHIs */ PreserveLCSSA); | ||||||
| 703 | ExitingBlock->eraseFromParent(); | ||||||
| 704 | } | ||||||
| 705 | } | ||||||
| 706 | |||||||
| 707 | // Changing exit conditions for blocks may affect exit counts of this loop and | ||||||
| 708 | // any of its paretns, so we must invalidate the entire subtree if we've made | ||||||
| 709 | // any changes. | ||||||
| 710 | if (Changed && SE) | ||||||
| 711 | SE->forgetTopmostLoop(L); | ||||||
| 712 | |||||||
| 713 | if (MSSAU && VerifyMemorySSA) | ||||||
| 714 | MSSAU->getMemorySSA()->verifyMemorySSA(); | ||||||
| 715 | |||||||
| 716 | return Changed; | ||||||
| 717 | } | ||||||
| 718 | |||||||
| 719 | bool llvm::simplifyLoop(Loop *L, DominatorTree *DT, LoopInfo *LI, | ||||||
| 720 | ScalarEvolution *SE, AssumptionCache *AC, | ||||||
| 721 | MemorySSAUpdater *MSSAU, bool PreserveLCSSA) { | ||||||
| 722 | bool Changed = false; | ||||||
| 723 | |||||||
| 724 | #ifndef NDEBUG1 | ||||||
| 725 | // If we're asked to preserve LCSSA, the loop nest needs to start in LCSSA | ||||||
| 726 | // form. | ||||||
| 727 | if (PreserveLCSSA) { | ||||||
| 728 | assert(DT && "DT not available.")((void)0); | ||||||
| 729 | assert(LI && "LI not available.")((void)0); | ||||||
| 730 | assert(L->isRecursivelyLCSSAForm(*DT, *LI) &&((void)0) | ||||||
| 731 | "Requested to preserve LCSSA, but it's already broken.")((void)0); | ||||||
| 732 | } | ||||||
| 733 | #endif | ||||||
| 734 | |||||||
| 735 | // Worklist maintains our depth-first queue of loops in this nest to process. | ||||||
| 736 | SmallVector<Loop *, 4> Worklist; | ||||||
| 737 | Worklist.push_back(L); | ||||||
| 738 | |||||||
| 739 | // Walk the worklist from front to back, pushing newly found sub loops onto | ||||||
| 740 | // the back. This will let us process loops from back to front in depth-first | ||||||
| 741 | // order. We can use this simple process because loops form a tree. | ||||||
| 742 | for (unsigned Idx = 0; Idx != Worklist.size(); ++Idx) { | ||||||
| 743 | Loop *L2 = Worklist[Idx]; | ||||||
| 744 | Worklist.append(L2->begin(), L2->end()); | ||||||
| 745 | } | ||||||
| 746 | |||||||
| 747 | while (!Worklist.empty()) | ||||||
| 748 | Changed |= simplifyOneLoop(Worklist.pop_back_val(), Worklist, DT, LI, SE, | ||||||
| 749 | AC, MSSAU, PreserveLCSSA); | ||||||
| 750 | |||||||
| 751 | return Changed; | ||||||
| 752 | } | ||||||
| 753 | |||||||
| 754 | namespace { | ||||||
| 755 | struct LoopSimplify : public FunctionPass { | ||||||
| 756 | static char ID; // Pass identification, replacement for typeid | ||||||
| 757 | LoopSimplify() : FunctionPass(ID) { | ||||||
| 758 | initializeLoopSimplifyPass(*PassRegistry::getPassRegistry()); | ||||||
| 759 | } | ||||||
| 760 | |||||||
| 761 | bool runOnFunction(Function &F) override; | ||||||
| 762 | |||||||
| 763 | void getAnalysisUsage(AnalysisUsage &AU) const override { | ||||||
| 764 | AU.addRequired<AssumptionCacheTracker>(); | ||||||
| 765 | |||||||
| 766 | // We need loop information to identify the loops... | ||||||
| 767 | AU.addRequired<DominatorTreeWrapperPass>(); | ||||||
| 768 | AU.addPreserved<DominatorTreeWrapperPass>(); | ||||||
| 769 | |||||||
| 770 | AU.addRequired<LoopInfoWrapperPass>(); | ||||||
| 771 | AU.addPreserved<LoopInfoWrapperPass>(); | ||||||
| 772 | |||||||
| 773 | AU.addPreserved<BasicAAWrapperPass>(); | ||||||
| 774 | AU.addPreserved<AAResultsWrapperPass>(); | ||||||
| 775 | AU.addPreserved<GlobalsAAWrapperPass>(); | ||||||
| 776 | AU.addPreserved<ScalarEvolutionWrapperPass>(); | ||||||
| 777 | AU.addPreserved<SCEVAAWrapperPass>(); | ||||||
| 778 | AU.addPreservedID(LCSSAID); | ||||||
| 779 | AU.addPreserved<DependenceAnalysisWrapperPass>(); | ||||||
| 780 | AU.addPreservedID(BreakCriticalEdgesID); // No critical edges added. | ||||||
| 781 | AU.addPreserved<BranchProbabilityInfoWrapperPass>(); | ||||||
| 782 | if (EnableMSSALoopDependency) | ||||||
| 783 | AU.addPreserved<MemorySSAWrapperPass>(); | ||||||
| 784 | } | ||||||
| 785 | |||||||
| 786 | /// verifyAnalysis() - Verify LoopSimplifyForm's guarantees. | ||||||
| 787 | void verifyAnalysis() const override; | ||||||
| 788 | }; | ||||||
| 789 | } | ||||||
| 790 | |||||||
| 791 | char LoopSimplify::ID = 0; | ||||||
| 792 | INITIALIZE_PASS_BEGIN(LoopSimplify, "loop-simplify",static void *initializeLoopSimplifyPassOnce(PassRegistry & Registry) { | ||||||
| 793 | "Canonicalize natural loops", false, false)static void *initializeLoopSimplifyPassOnce(PassRegistry & Registry) { | ||||||
| 794 | INITIALIZE_PASS_DEPENDENCY(AssumptionCacheTracker)initializeAssumptionCacheTrackerPass(Registry); | ||||||
| 795 | INITIALIZE_PASS_DEPENDENCY(DominatorTreeWrapperPass)initializeDominatorTreeWrapperPassPass(Registry); | ||||||
| 796 | INITIALIZE_PASS_DEPENDENCY(LoopInfoWrapperPass)initializeLoopInfoWrapperPassPass(Registry); | ||||||
| 797 | INITIALIZE_PASS_END(LoopSimplify, "loop-simplify",PassInfo *PI = new PassInfo( "Canonicalize natural loops", "loop-simplify" , &LoopSimplify::ID, PassInfo::NormalCtor_t(callDefaultCtor <LoopSimplify>), false, false); Registry.registerPass(* PI, true); return PI; } static llvm::once_flag InitializeLoopSimplifyPassFlag ; void llvm::initializeLoopSimplifyPass(PassRegistry &Registry ) { llvm::call_once(InitializeLoopSimplifyPassFlag, initializeLoopSimplifyPassOnce , std::ref(Registry)); } | ||||||
| 798 | "Canonicalize natural loops", false, false)PassInfo *PI = new PassInfo( "Canonicalize natural loops", "loop-simplify" , &LoopSimplify::ID, PassInfo::NormalCtor_t(callDefaultCtor <LoopSimplify>), false, false); Registry.registerPass(* PI, true); return PI; } static llvm::once_flag InitializeLoopSimplifyPassFlag ; void llvm::initializeLoopSimplifyPass(PassRegistry &Registry ) { llvm::call_once(InitializeLoopSimplifyPassFlag, initializeLoopSimplifyPassOnce , std::ref(Registry)); } | ||||||
| 799 | |||||||
| 800 | // Publicly exposed interface to pass... | ||||||
| 801 | char &llvm::LoopSimplifyID = LoopSimplify::ID; | ||||||
| 802 | Pass *llvm::createLoopSimplifyPass() { return new LoopSimplify(); } | ||||||
| 803 | |||||||
| 804 | /// runOnFunction - Run down all loops in the CFG (recursively, but we could do | ||||||
| 805 | /// it in any convenient order) inserting preheaders... | ||||||
| 806 | /// | ||||||
| 807 | bool LoopSimplify::runOnFunction(Function &F) { | ||||||
| 808 | bool Changed = false; | ||||||
| 809 | LoopInfo *LI = &getAnalysis<LoopInfoWrapperPass>().getLoopInfo(); | ||||||
| 810 | DominatorTree *DT = &getAnalysis<DominatorTreeWrapperPass>().getDomTree(); | ||||||
| 811 | auto *SEWP = getAnalysisIfAvailable<ScalarEvolutionWrapperPass>(); | ||||||
| 812 | ScalarEvolution *SE = SEWP ? &SEWP->getSE() : nullptr; | ||||||
| 813 | AssumptionCache *AC = | ||||||
| 814 | &getAnalysis<AssumptionCacheTracker>().getAssumptionCache(F); | ||||||
| 815 | MemorySSA *MSSA = nullptr; | ||||||
| 816 | std::unique_ptr<MemorySSAUpdater> MSSAU; | ||||||
| 817 | if (EnableMSSALoopDependency) { | ||||||
| 818 | auto *MSSAAnalysis = getAnalysisIfAvailable<MemorySSAWrapperPass>(); | ||||||
| 819 | if (MSSAAnalysis) { | ||||||
| 820 | MSSA = &MSSAAnalysis->getMSSA(); | ||||||
| 821 | MSSAU = std::make_unique<MemorySSAUpdater>(MSSA); | ||||||
| 822 | } | ||||||
| 823 | } | ||||||
| 824 | |||||||
| 825 | bool PreserveLCSSA = mustPreserveAnalysisID(LCSSAID); | ||||||
| 826 | |||||||
| 827 | // Simplify each loop nest in the function. | ||||||
| 828 | for (auto *L : *LI) | ||||||
| 829 | Changed |= simplifyLoop(L, DT, LI, SE, AC, MSSAU.get(), PreserveLCSSA); | ||||||
| 830 | |||||||
| 831 | #ifndef NDEBUG1 | ||||||
| 832 | if (PreserveLCSSA) { | ||||||
| 833 | bool InLCSSA = all_of( | ||||||
| 834 | *LI, [&](Loop *L) { return L->isRecursivelyLCSSAForm(*DT, *LI); }); | ||||||
| 835 | assert(InLCSSA && "LCSSA is broken after loop-simplify.")((void)0); | ||||||
| 836 | } | ||||||
| 837 | #endif | ||||||
| 838 | return Changed; | ||||||
| 839 | } | ||||||
| 840 | |||||||
| 841 | PreservedAnalyses LoopSimplifyPass::run(Function &F, | ||||||
| 842 | FunctionAnalysisManager &AM) { | ||||||
| 843 | bool Changed = false; | ||||||
| 844 | LoopInfo *LI = &AM.getResult<LoopAnalysis>(F); | ||||||
| 845 | DominatorTree *DT = &AM.getResult<DominatorTreeAnalysis>(F); | ||||||
| 846 | ScalarEvolution *SE = AM.getCachedResult<ScalarEvolutionAnalysis>(F); | ||||||
| 847 | AssumptionCache *AC = &AM.getResult<AssumptionAnalysis>(F); | ||||||
| 848 | auto *MSSAAnalysis = AM.getCachedResult<MemorySSAAnalysis>(F); | ||||||
| 849 | std::unique_ptr<MemorySSAUpdater> MSSAU; | ||||||
| 850 | if (MSSAAnalysis) { | ||||||
| 851 | auto *MSSA = &MSSAAnalysis->getMSSA(); | ||||||
| 852 | MSSAU = std::make_unique<MemorySSAUpdater>(MSSA); | ||||||
| 853 | } | ||||||
| 854 | |||||||
| 855 | |||||||
| 856 | // Note that we don't preserve LCSSA in the new PM, if you need it run LCSSA | ||||||
| 857 | // after simplifying the loops. MemorySSA is preserved if it exists. | ||||||
| 858 | for (auto *L : *LI) | ||||||
| 859 | Changed |= | ||||||
| 860 | simplifyLoop(L, DT, LI, SE, AC, MSSAU.get(), /*PreserveLCSSA*/ false); | ||||||
| 861 | |||||||
| 862 | if (!Changed) | ||||||
| 863 | return PreservedAnalyses::all(); | ||||||
| 864 | |||||||
| 865 | PreservedAnalyses PA; | ||||||
| 866 | PA.preserve<DominatorTreeAnalysis>(); | ||||||
| 867 | PA.preserve<LoopAnalysis>(); | ||||||
| 868 | PA.preserve<ScalarEvolutionAnalysis>(); | ||||||
| 869 | PA.preserve<DependenceAnalysis>(); | ||||||
| 870 | if (MSSAAnalysis) | ||||||
| 871 | PA.preserve<MemorySSAAnalysis>(); | ||||||
| 872 | // BPI maps conditional terminators to probabilities, LoopSimplify can insert | ||||||
| 873 | // blocks, but it does so only by splitting existing blocks and edges. This | ||||||
| 874 | // results in the interesting property that all new terminators inserted are | ||||||
| 875 | // unconditional branches which do not appear in BPI. All deletions are | ||||||
| 876 | // handled via ValueHandle callbacks w/in BPI. | ||||||
| 877 | PA.preserve<BranchProbabilityAnalysis>(); | ||||||
| 878 | return PA; | ||||||
| 879 | } | ||||||
| 880 | |||||||
| 881 | // FIXME: Restore this code when we re-enable verification in verifyAnalysis | ||||||
| 882 | // below. | ||||||
| 883 | #if 0 | ||||||
| 884 | static void verifyLoop(Loop *L) { | ||||||
| 885 | // Verify subloops. | ||||||
| 886 | for (Loop::iterator I = L->begin(), E = L->end(); I != E; ++I) | ||||||
| 887 | verifyLoop(*I); | ||||||
| 888 | |||||||
| 889 | // It used to be possible to just assert L->isLoopSimplifyForm(), however | ||||||
| 890 | // with the introduction of indirectbr, there are now cases where it's | ||||||
| 891 | // not possible to transform a loop as necessary. We can at least check | ||||||
| 892 | // that there is an indirectbr near any time there's trouble. | ||||||
| 893 | |||||||
| 894 | // Indirectbr can interfere with preheader and unique backedge insertion. | ||||||
| 895 | if (!L->getLoopPreheader() || !L->getLoopLatch()) { | ||||||
| 896 | bool HasIndBrPred = false; | ||||||
| 897 | for (BasicBlock *Pred : predecessors(L->getHeader())) | ||||||
| 898 | if (isa<IndirectBrInst>(Pred->getTerminator())) { | ||||||
| 899 | HasIndBrPred = true; | ||||||
| 900 | break; | ||||||
| 901 | } | ||||||
| 902 | assert(HasIndBrPred &&((void)0) | ||||||
| 903 | "LoopSimplify has no excuse for missing loop header info!")((void)0); | ||||||
| 904 | (void)HasIndBrPred; | ||||||
| 905 | } | ||||||
| 906 | |||||||
| 907 | // Indirectbr can interfere with exit block canonicalization. | ||||||
| 908 | if (!L->hasDedicatedExits()) { | ||||||
| 909 | bool HasIndBrExiting = false; | ||||||
| 910 | SmallVector<BasicBlock*, 8> ExitingBlocks; | ||||||
| 911 | L->getExitingBlocks(ExitingBlocks); | ||||||
| 912 | for (unsigned i = 0, e = ExitingBlocks.size(); i != e; ++i) { | ||||||
| 913 | if (isa<IndirectBrInst>((ExitingBlocks[i])->getTerminator())) { | ||||||
| 914 | HasIndBrExiting = true; | ||||||
| 915 | break; | ||||||
| 916 | } | ||||||
| 917 | } | ||||||
| 918 | |||||||
| 919 | assert(HasIndBrExiting &&((void)0) | ||||||
| 920 | "LoopSimplify has no excuse for missing exit block info!")((void)0); | ||||||
| 921 | (void)HasIndBrExiting; | ||||||
| 922 | } | ||||||
| 923 | } | ||||||
| 924 | #endif | ||||||
| 925 | |||||||
| 926 | void LoopSimplify::verifyAnalysis() const { | ||||||
| 927 | // FIXME: This routine is being called mid-way through the loop pass manager | ||||||
| 928 | // as loop passes destroy this analysis. That's actually fine, but we have no | ||||||
| 929 | // way of expressing that here. Once all of the passes that destroy this are | ||||||
| 930 | // hoisted out of the loop pass manager we can add back verification here. | ||||||
| 931 | #if 0 | ||||||
| 932 | for (LoopInfo::iterator I = LI->begin(), E = LI->end(); I != E; ++I) | ||||||
| 933 | verifyLoop(*I); | ||||||
| 934 | #endif | ||||||
| 935 | } |
| 1 | //===- GenericDomTree.h - Generic dominator trees for graphs ----*- C++ -*-===// | ||||||
| 2 | // | ||||||
| 3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. | ||||||
| 4 | // See https://llvm.org/LICENSE.txt for license information. | ||||||
| 5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception | ||||||
| 6 | // | ||||||
| 7 | //===----------------------------------------------------------------------===// | ||||||
| 8 | /// \file | ||||||
| 9 | /// | ||||||
| 10 | /// This file defines a set of templates that efficiently compute a dominator | ||||||
| 11 | /// tree over a generic graph. This is used typically in LLVM for fast | ||||||
| 12 | /// dominance queries on the CFG, but is fully generic w.r.t. the underlying | ||||||
| 13 | /// graph types. | ||||||
| 14 | /// | ||||||
| 15 | /// Unlike ADT/* graph algorithms, generic dominator tree has more requirements | ||||||
| 16 | /// on the graph's NodeRef. The NodeRef should be a pointer and, | ||||||
| 17 | /// NodeRef->getParent() must return the parent node that is also a pointer. | ||||||
| 18 | /// | ||||||
| 19 | /// FIXME: Maybe GenericDomTree needs a TreeTraits, instead of GraphTraits. | ||||||
| 20 | /// | ||||||
| 21 | //===----------------------------------------------------------------------===// | ||||||
| 22 | |||||||
| 23 | #ifndef LLVM_SUPPORT_GENERICDOMTREE_H | ||||||
| 24 | #define LLVM_SUPPORT_GENERICDOMTREE_H | ||||||
| 25 | |||||||
| 26 | #include "llvm/ADT/DenseMap.h" | ||||||
| 27 | #include "llvm/ADT/GraphTraits.h" | ||||||
| 28 | #include "llvm/ADT/STLExtras.h" | ||||||
| 29 | #include "llvm/ADT/SmallPtrSet.h" | ||||||
| 30 | #include "llvm/ADT/SmallVector.h" | ||||||
| 31 | #include "llvm/Support/CFGDiff.h" | ||||||
| 32 | #include "llvm/Support/CFGUpdate.h" | ||||||
| 33 | #include "llvm/Support/raw_ostream.h" | ||||||
| 34 | #include <algorithm> | ||||||
| 35 | #include <cassert> | ||||||
| 36 | #include <cstddef> | ||||||
| 37 | #include <iterator> | ||||||
| 38 | #include <memory> | ||||||
| 39 | #include <type_traits> | ||||||
| 40 | #include <utility> | ||||||
| 41 | |||||||
| 42 | namespace llvm { | ||||||
| 43 | |||||||
| 44 | template <typename NodeT, bool IsPostDom> | ||||||
| 45 | class DominatorTreeBase; | ||||||
| 46 | |||||||
| 47 | namespace DomTreeBuilder { | ||||||
| 48 | template <typename DomTreeT> | ||||||
| 49 | struct SemiNCAInfo; | ||||||
| 50 | } // namespace DomTreeBuilder | ||||||
| 51 | |||||||
| 52 | /// Base class for the actual dominator tree node. | ||||||
| 53 | template <class NodeT> class DomTreeNodeBase { | ||||||
| 54 | friend class PostDominatorTree; | ||||||
| 55 | friend class DominatorTreeBase<NodeT, false>; | ||||||
| 56 | friend class DominatorTreeBase<NodeT, true>; | ||||||
| 57 | friend struct DomTreeBuilder::SemiNCAInfo<DominatorTreeBase<NodeT, false>>; | ||||||
| 58 | friend struct DomTreeBuilder::SemiNCAInfo<DominatorTreeBase<NodeT, true>>; | ||||||
| 59 | |||||||
| 60 | NodeT *TheBB; | ||||||
| 61 | DomTreeNodeBase *IDom; | ||||||
| 62 | unsigned Level; | ||||||
| 63 | SmallVector<DomTreeNodeBase *, 4> Children; | ||||||
| 64 | mutable unsigned DFSNumIn = ~0; | ||||||
| 65 | mutable unsigned DFSNumOut = ~0; | ||||||
| 66 | |||||||
| 67 | public: | ||||||
| 68 | DomTreeNodeBase(NodeT *BB, DomTreeNodeBase *iDom) | ||||||
| 69 | : TheBB(BB), IDom(iDom), Level(IDom ? IDom->Level + 1 : 0) {} | ||||||
| 70 | |||||||
| 71 | using iterator = typename SmallVector<DomTreeNodeBase *, 4>::iterator; | ||||||
| 72 | using const_iterator = | ||||||
| 73 | typename SmallVector<DomTreeNodeBase *, 4>::const_iterator; | ||||||
| 74 | |||||||
| 75 | iterator begin() { return Children.begin(); } | ||||||
| 76 | iterator end() { return Children.end(); } | ||||||
| 77 | const_iterator begin() const { return Children.begin(); } | ||||||
| 78 | const_iterator end() const { return Children.end(); } | ||||||
| 79 | |||||||
| 80 | DomTreeNodeBase *const &back() const { return Children.back(); } | ||||||
| 81 | DomTreeNodeBase *&back() { return Children.back(); } | ||||||
| 82 | |||||||
| 83 | iterator_range<iterator> children() { return make_range(begin(), end()); } | ||||||
| 84 | iterator_range<const_iterator> children() const { | ||||||
| 85 | return make_range(begin(), end()); | ||||||
| 86 | } | ||||||
| 87 | |||||||
| 88 | NodeT *getBlock() const { return TheBB; } | ||||||
| 89 | DomTreeNodeBase *getIDom() const { return IDom; } | ||||||
| 90 | unsigned getLevel() const { return Level; } | ||||||
| 91 | |||||||
| 92 | std::unique_ptr<DomTreeNodeBase> addChild( | ||||||
| 93 | std::unique_ptr<DomTreeNodeBase> C) { | ||||||
| 94 | Children.push_back(C.get()); | ||||||
| 95 | return C; | ||||||
| 96 | } | ||||||
| 97 | |||||||
| 98 | bool isLeaf() const { return Children.empty(); } | ||||||
| 99 | size_t getNumChildren() const { return Children.size(); } | ||||||
| 100 | |||||||
| 101 | void clearAllChildren() { Children.clear(); } | ||||||
| 102 | |||||||
| 103 | bool compare(const DomTreeNodeBase *Other) const { | ||||||
| 104 | if (getNumChildren() != Other->getNumChildren()) | ||||||
| 105 | return true; | ||||||
| 106 | |||||||
| 107 | if (Level != Other->Level) return true; | ||||||
| 108 | |||||||
| 109 | SmallPtrSet<const NodeT *, 4> OtherChildren; | ||||||
| 110 | for (const DomTreeNodeBase *I : *Other) { | ||||||
| 111 | const NodeT *Nd = I->getBlock(); | ||||||
| 112 | OtherChildren.insert(Nd); | ||||||
| 113 | } | ||||||
| 114 | |||||||
| 115 | for (const DomTreeNodeBase *I : *this) { | ||||||
| 116 | const NodeT *N = I->getBlock(); | ||||||
| 117 | if (OtherChildren.count(N) == 0) | ||||||
| 118 | return true; | ||||||
| 119 | } | ||||||
| 120 | return false; | ||||||
| 121 | } | ||||||
| 122 | |||||||
| 123 | void setIDom(DomTreeNodeBase *NewIDom) { | ||||||
| 124 | assert(IDom && "No immediate dominator?")((void)0); | ||||||
| 125 | if (IDom == NewIDom) return; | ||||||
| 126 | |||||||
| 127 | auto I = find(IDom->Children, this); | ||||||
| 128 | assert(I != IDom->Children.end() &&((void)0) | ||||||
| 129 | "Not in immediate dominator children set!")((void)0); | ||||||
| 130 | // I am no longer your child... | ||||||
| 131 | IDom->Children.erase(I); | ||||||
| 132 | |||||||
| 133 | // Switch to new dominator | ||||||
| 134 | IDom = NewIDom; | ||||||
| 135 | IDom->Children.push_back(this); | ||||||
| 136 | |||||||
| 137 | UpdateLevel(); | ||||||
| 138 | } | ||||||
| 139 | |||||||
| 140 | /// getDFSNumIn/getDFSNumOut - These return the DFS visitation order for nodes | ||||||
| 141 | /// in the dominator tree. They are only guaranteed valid if | ||||||
| 142 | /// updateDFSNumbers() has been called. | ||||||
| 143 | unsigned getDFSNumIn() const { return DFSNumIn; } | ||||||
| 144 | unsigned getDFSNumOut() const { return DFSNumOut; } | ||||||
| 145 | |||||||
| 146 | private: | ||||||
| 147 | // Return true if this node is dominated by other. Use this only if DFS info | ||||||
| 148 | // is valid. | ||||||
| 149 | bool DominatedBy(const DomTreeNodeBase *other) const { | ||||||
| 150 | return this->DFSNumIn >= other->DFSNumIn && | ||||||
| 151 | this->DFSNumOut <= other->DFSNumOut; | ||||||
| 152 | } | ||||||
| 153 | |||||||
| 154 | void UpdateLevel() { | ||||||
| 155 | assert(IDom)((void)0); | ||||||
| 156 | if (Level == IDom->Level + 1) return; | ||||||
| 157 | |||||||
| 158 | SmallVector<DomTreeNodeBase *, 64> WorkStack = {this}; | ||||||
| 159 | |||||||
| 160 | while (!WorkStack.empty()) { | ||||||
| 161 | DomTreeNodeBase *Current = WorkStack.pop_back_val(); | ||||||
| 162 | Current->Level = Current->IDom->Level + 1; | ||||||
| 163 | |||||||
| 164 | for (DomTreeNodeBase *C : *Current) { | ||||||
| 165 | assert(C->IDom)((void)0); | ||||||
| 166 | if (C->Level != C->IDom->Level + 1) WorkStack.push_back(C); | ||||||
| 167 | } | ||||||
| 168 | } | ||||||
| 169 | } | ||||||
| 170 | }; | ||||||
| 171 | |||||||
| 172 | template <class NodeT> | ||||||
| 173 | raw_ostream &operator<<(raw_ostream &O, const DomTreeNodeBase<NodeT> *Node) { | ||||||
| 174 | if (Node->getBlock()) | ||||||
| 175 | Node->getBlock()->printAsOperand(O, false); | ||||||
| 176 | else | ||||||
| 177 | O << " <<exit node>>"; | ||||||
| 178 | |||||||
| 179 | O << " {" << Node->getDFSNumIn() << "," << Node->getDFSNumOut() << "} [" | ||||||
| 180 | << Node->getLevel() << "]\n"; | ||||||
| 181 | |||||||
| 182 | return O; | ||||||
| 183 | } | ||||||
| 184 | |||||||
| 185 | template <class NodeT> | ||||||
| 186 | void PrintDomTree(const DomTreeNodeBase<NodeT> *N, raw_ostream &O, | ||||||
| 187 | unsigned Lev) { | ||||||
| 188 | O.indent(2 * Lev) << "[" << Lev << "] " << N; | ||||||
| 189 | for (typename DomTreeNodeBase<NodeT>::const_iterator I = N->begin(), | ||||||
| 190 | E = N->end(); | ||||||
| 191 | I != E; ++I) | ||||||
| 192 | PrintDomTree<NodeT>(*I, O, Lev + 1); | ||||||
| 193 | } | ||||||
| 194 | |||||||
| 195 | namespace DomTreeBuilder { | ||||||
| 196 | // The routines below are provided in a separate header but referenced here. | ||||||
| 197 | template <typename DomTreeT> | ||||||
| 198 | void Calculate(DomTreeT &DT); | ||||||
| 199 | |||||||
| 200 | template <typename DomTreeT> | ||||||
| 201 | void CalculateWithUpdates(DomTreeT &DT, | ||||||
| 202 | ArrayRef<typename DomTreeT::UpdateType> Updates); | ||||||
| 203 | |||||||
| 204 | template <typename DomTreeT> | ||||||
| 205 | void InsertEdge(DomTreeT &DT, typename DomTreeT::NodePtr From, | ||||||
| 206 | typename DomTreeT::NodePtr To); | ||||||
| 207 | |||||||
| 208 | template <typename DomTreeT> | ||||||
| 209 | void DeleteEdge(DomTreeT &DT, typename DomTreeT::NodePtr From, | ||||||
| 210 | typename DomTreeT::NodePtr To); | ||||||
| 211 | |||||||
| 212 | template <typename DomTreeT> | ||||||
| 213 | void ApplyUpdates(DomTreeT &DT, | ||||||
| 214 | GraphDiff<typename DomTreeT::NodePtr, | ||||||
| 215 | DomTreeT::IsPostDominator> &PreViewCFG, | ||||||
| 216 | GraphDiff<typename DomTreeT::NodePtr, | ||||||
| 217 | DomTreeT::IsPostDominator> *PostViewCFG); | ||||||
| 218 | |||||||
| 219 | template <typename DomTreeT> | ||||||
| 220 | bool Verify(const DomTreeT &DT, typename DomTreeT::VerificationLevel VL); | ||||||
| 221 | } // namespace DomTreeBuilder | ||||||
| 222 | |||||||
| 223 | /// Core dominator tree base class. | ||||||
| 224 | /// | ||||||
| 225 | /// This class is a generic template over graph nodes. It is instantiated for | ||||||
| 226 | /// various graphs in the LLVM IR or in the code generator. | ||||||
| 227 | template <typename NodeT, bool IsPostDom> | ||||||
| 228 | class DominatorTreeBase { | ||||||
| 229 | public: | ||||||
| 230 | static_assert(std::is_pointer<typename GraphTraits<NodeT *>::NodeRef>::value, | ||||||
| 231 | "Currently DominatorTreeBase supports only pointer nodes"); | ||||||
| 232 | using NodeType = NodeT; | ||||||
| 233 | using NodePtr = NodeT *; | ||||||
| 234 | using ParentPtr = decltype(std::declval<NodeT *>()->getParent()); | ||||||
| 235 | static_assert(std::is_pointer<ParentPtr>::value, | ||||||
| 236 | "Currently NodeT's parent must be a pointer type"); | ||||||
| 237 | using ParentType = std::remove_pointer_t<ParentPtr>; | ||||||
| 238 | static constexpr bool IsPostDominator = IsPostDom; | ||||||
| 239 | |||||||
| 240 | using UpdateType = cfg::Update<NodePtr>; | ||||||
| 241 | using UpdateKind = cfg::UpdateKind; | ||||||
| 242 | static constexpr UpdateKind Insert = UpdateKind::Insert; | ||||||
| 243 | static constexpr UpdateKind Delete = UpdateKind::Delete; | ||||||
| 244 | |||||||
| 245 | enum class VerificationLevel { Fast, Basic, Full }; | ||||||
| 246 | |||||||
| 247 | protected: | ||||||
| 248 | // Dominators always have a single root, postdominators can have more. | ||||||
| 249 | SmallVector<NodeT *, IsPostDom ? 4 : 1> Roots; | ||||||
| 250 | |||||||
| 251 | using DomTreeNodeMapType = | ||||||
| 252 | DenseMap<NodeT *, std::unique_ptr<DomTreeNodeBase<NodeT>>>; | ||||||
| 253 | DomTreeNodeMapType DomTreeNodes; | ||||||
| 254 | DomTreeNodeBase<NodeT> *RootNode = nullptr; | ||||||
| 255 | ParentPtr Parent = nullptr; | ||||||
| 256 | |||||||
| 257 | mutable bool DFSInfoValid = false; | ||||||
| 258 | mutable unsigned int SlowQueries = 0; | ||||||
| 259 | |||||||
| 260 | friend struct DomTreeBuilder::SemiNCAInfo<DominatorTreeBase>; | ||||||
| 261 | |||||||
| 262 | public: | ||||||
| 263 | DominatorTreeBase() {} | ||||||
| 264 | |||||||
| 265 | DominatorTreeBase(DominatorTreeBase &&Arg) | ||||||
| 266 | : Roots(std::move(Arg.Roots)), | ||||||
| 267 | DomTreeNodes(std::move(Arg.DomTreeNodes)), | ||||||
| 268 | RootNode(Arg.RootNode), | ||||||
| 269 | Parent(Arg.Parent), | ||||||
| 270 | DFSInfoValid(Arg.DFSInfoValid), | ||||||
| 271 | SlowQueries(Arg.SlowQueries) { | ||||||
| 272 | Arg.wipe(); | ||||||
| 273 | } | ||||||
| 274 | |||||||
| 275 | DominatorTreeBase &operator=(DominatorTreeBase &&RHS) { | ||||||
| 276 | Roots = std::move(RHS.Roots); | ||||||
| 277 | DomTreeNodes = std::move(RHS.DomTreeNodes); | ||||||
| 278 | RootNode = RHS.RootNode; | ||||||
| 279 | Parent = RHS.Parent; | ||||||
| 280 | DFSInfoValid = RHS.DFSInfoValid; | ||||||
| 281 | SlowQueries = RHS.SlowQueries; | ||||||
| 282 | RHS.wipe(); | ||||||
| 283 | return *this; | ||||||
| 284 | } | ||||||
| 285 | |||||||
| 286 | DominatorTreeBase(const DominatorTreeBase &) = delete; | ||||||
| 287 | DominatorTreeBase &operator=(const DominatorTreeBase &) = delete; | ||||||
| 288 | |||||||
| 289 | /// Iteration over roots. | ||||||
| 290 | /// | ||||||
| 291 | /// This may include multiple blocks if we are computing post dominators. | ||||||
| 292 | /// For forward dominators, this will always be a single block (the entry | ||||||
| 293 | /// block). | ||||||
| 294 | using root_iterator = typename SmallVectorImpl<NodeT *>::iterator; | ||||||
| 295 | using const_root_iterator = typename SmallVectorImpl<NodeT *>::const_iterator; | ||||||
| 296 | |||||||
| 297 | root_iterator root_begin() { return Roots.begin(); } | ||||||
| 298 | const_root_iterator root_begin() const { return Roots.begin(); } | ||||||
| 299 | root_iterator root_end() { return Roots.end(); } | ||||||
| 300 | const_root_iterator root_end() const { return Roots.end(); } | ||||||
| 301 | |||||||
| 302 | size_t root_size() const { return Roots.size(); } | ||||||
| 303 | |||||||
| 304 | iterator_range<root_iterator> roots() { | ||||||
| 305 | return make_range(root_begin(), root_end()); | ||||||
| 306 | } | ||||||
| 307 | iterator_range<const_root_iterator> roots() const { | ||||||
| 308 | return make_range(root_begin(), root_end()); | ||||||
| 309 | } | ||||||
| 310 | |||||||
| 311 | /// isPostDominator - Returns true if analysis based of postdoms | ||||||
| 312 | /// | ||||||
| 313 | bool isPostDominator() const { return IsPostDominator; } | ||||||
| 314 | |||||||
| 315 | /// compare - Return false if the other dominator tree base matches this | ||||||
| 316 | /// dominator tree base. Otherwise return true. | ||||||
| 317 | bool compare(const DominatorTreeBase &Other) const { | ||||||
| 318 | if (Parent != Other.Parent) return true; | ||||||
| 319 | |||||||
| 320 | if (Roots.size() != Other.Roots.size()) | ||||||
| 321 | return true; | ||||||
| 322 | |||||||
| 323 | if (!std::is_permutation(Roots.begin(), Roots.end(), Other.Roots.begin())) | ||||||
| 324 | return true; | ||||||
| 325 | |||||||
| 326 | const DomTreeNodeMapType &OtherDomTreeNodes = Other.DomTreeNodes; | ||||||
| 327 | if (DomTreeNodes.size() != OtherDomTreeNodes.size()) | ||||||
| 328 | return true; | ||||||
| 329 | |||||||
| 330 | for (const auto &DomTreeNode : DomTreeNodes) { | ||||||
| 331 | NodeT *BB = DomTreeNode.first; | ||||||
| 332 | typename DomTreeNodeMapType::const_iterator OI = | ||||||
| 333 | OtherDomTreeNodes.find(BB); | ||||||
| 334 | if (OI == OtherDomTreeNodes.end()) | ||||||
| 335 | return true; | ||||||
| 336 | |||||||
| 337 | DomTreeNodeBase<NodeT> &MyNd = *DomTreeNode.second; | ||||||
| 338 | DomTreeNodeBase<NodeT> &OtherNd = *OI->second; | ||||||
| 339 | |||||||
| 340 | if (MyNd.compare(&OtherNd)) | ||||||
| 341 | return true; | ||||||
| 342 | } | ||||||
| 343 | |||||||
| 344 | return false; | ||||||
| 345 | } | ||||||
| 346 | |||||||
| 347 | /// getNode - return the (Post)DominatorTree node for the specified basic | ||||||
| 348 | /// block. This is the same as using operator[] on this class. The result | ||||||
| 349 | /// may (but is not required to) be null for a forward (backwards) | ||||||
| 350 | /// statically unreachable block. | ||||||
| 351 | DomTreeNodeBase<NodeT> *getNode(const NodeT *BB) const { | ||||||
| 352 | auto I = DomTreeNodes.find(BB); | ||||||
| 353 | if (I != DomTreeNodes.end()) | ||||||
| 354 | return I->second.get(); | ||||||
| 355 | return nullptr; | ||||||
| 356 | } | ||||||
| 357 | |||||||
| 358 | /// See getNode. | ||||||
| 359 | DomTreeNodeBase<NodeT> *operator[](const NodeT *BB) const { | ||||||
| 360 | return getNode(BB); | ||||||
| 361 | } | ||||||
| 362 | |||||||
| 363 | /// getRootNode - This returns the entry node for the CFG of the function. If | ||||||
| 364 | /// this tree represents the post-dominance relations for a function, however, | ||||||
| 365 | /// this root may be a node with the block == NULL. This is the case when | ||||||
| 366 | /// there are multiple exit nodes from a particular function. Consumers of | ||||||
| 367 | /// post-dominance information must be capable of dealing with this | ||||||
| 368 | /// possibility. | ||||||
| 369 | /// | ||||||
| 370 | DomTreeNodeBase<NodeT> *getRootNode() { return RootNode; } | ||||||
| 371 | const DomTreeNodeBase<NodeT> *getRootNode() const { return RootNode; } | ||||||
| 372 | |||||||
| 373 | /// Get all nodes dominated by R, including R itself. | ||||||
| 374 | void getDescendants(NodeT *R, SmallVectorImpl<NodeT *> &Result) const { | ||||||
| 375 | Result.clear(); | ||||||
| 376 | const DomTreeNodeBase<NodeT> *RN = getNode(R); | ||||||
| 377 | if (!RN) | ||||||
| 378 | return; // If R is unreachable, it will not be present in the DOM tree. | ||||||
| 379 | SmallVector<const DomTreeNodeBase<NodeT> *, 8> WL; | ||||||
| 380 | WL.push_back(RN); | ||||||
| 381 | |||||||
| 382 | while (!WL.empty()) { | ||||||
| 383 | const DomTreeNodeBase<NodeT> *N = WL.pop_back_val(); | ||||||
| 384 | Result.push_back(N->getBlock()); | ||||||
| 385 | WL.append(N->begin(), N->end()); | ||||||
| 386 | } | ||||||
| 387 | } | ||||||
| 388 | |||||||
| 389 | /// properlyDominates - Returns true iff A dominates B and A != B. | ||||||
| 390 | /// Note that this is not a constant time operation! | ||||||
| 391 | /// | ||||||
| 392 | bool properlyDominates(const DomTreeNodeBase<NodeT> *A, | ||||||
| 393 | const DomTreeNodeBase<NodeT> *B) const { | ||||||
| 394 | if (!A || !B) | ||||||
| 395 | return false; | ||||||
| 396 | if (A == B) | ||||||
| 397 | return false; | ||||||
| 398 | return dominates(A, B); | ||||||
| 399 | } | ||||||
| 400 | |||||||
| 401 | bool properlyDominates(const NodeT *A, const NodeT *B) const; | ||||||
| 402 | |||||||
| 403 | /// isReachableFromEntry - Return true if A is dominated by the entry | ||||||
| 404 | /// block of the function containing it. | ||||||
| 405 | bool isReachableFromEntry(const NodeT *A) const { | ||||||
| 406 | assert(!this->isPostDominator() &&((void)0) | ||||||
| 407 | "This is not implemented for post dominators")((void)0); | ||||||
| 408 | return isReachableFromEntry(getNode(const_cast<NodeT *>(A))); | ||||||
| 409 | } | ||||||
| 410 | |||||||
| 411 | bool isReachableFromEntry(const DomTreeNodeBase<NodeT> *A) const { return A; } | ||||||
| 412 | |||||||
| 413 | /// dominates - Returns true iff A dominates B. Note that this is not a | ||||||
| 414 | /// constant time operation! | ||||||
| 415 | /// | ||||||
| 416 | bool dominates(const DomTreeNodeBase<NodeT> *A, | ||||||
| 417 | const DomTreeNodeBase<NodeT> *B) const { | ||||||
| 418 | // A node trivially dominates itself. | ||||||
| 419 | if (B == A) | ||||||
| 420 | return true; | ||||||
| 421 | |||||||
| 422 | // An unreachable node is dominated by anything. | ||||||
| 423 | if (!isReachableFromEntry(B)) | ||||||
| 424 | return true; | ||||||
| 425 | |||||||
| 426 | // And dominates nothing. | ||||||
| 427 | if (!isReachableFromEntry(A)) | ||||||
| 428 | return false; | ||||||
| 429 | |||||||
| 430 | if (B->getIDom() == A) return true; | ||||||
| 431 | |||||||
| 432 | if (A->getIDom() == B) return false; | ||||||
| 433 | |||||||
| 434 | // A can only dominate B if it is higher in the tree. | ||||||
| 435 | if (A->getLevel() >= B->getLevel()) return false; | ||||||
| 436 | |||||||
| 437 | // Compare the result of the tree walk and the dfs numbers, if expensive | ||||||
| 438 | // checks are enabled. | ||||||
| 439 | #ifdef EXPENSIVE_CHECKS | ||||||
| 440 | assert((!DFSInfoValid ||((void)0) | ||||||
| 441 | (dominatedBySlowTreeWalk(A, B) == B->DominatedBy(A))) &&((void)0) | ||||||
| 442 | "Tree walk disagrees with dfs numbers!")((void)0); | ||||||
| 443 | #endif | ||||||
| 444 | |||||||
| 445 | if (DFSInfoValid) | ||||||
| 446 | return B->DominatedBy(A); | ||||||
| 447 | |||||||
| 448 | // If we end up with too many slow queries, just update the | ||||||
| 449 | // DFS numbers on the theory that we are going to keep querying. | ||||||
| 450 | SlowQueries++; | ||||||
| 451 | if (SlowQueries > 32) { | ||||||
| 452 | updateDFSNumbers(); | ||||||
| 453 | return B->DominatedBy(A); | ||||||
| 454 | } | ||||||
| 455 | |||||||
| 456 | return dominatedBySlowTreeWalk(A, B); | ||||||
| 457 | } | ||||||
| 458 | |||||||
| 459 | bool dominates(const NodeT *A, const NodeT *B) const; | ||||||
| 460 | |||||||
| 461 | NodeT *getRoot() const { | ||||||
| 462 | assert(this->Roots.size() == 1 && "Should always have entry node!")((void)0); | ||||||
| 463 | return this->Roots[0]; | ||||||
| 464 | } | ||||||
| 465 | |||||||
| 466 | /// Find nearest common dominator basic block for basic block A and B. A and B | ||||||
| 467 | /// must have tree nodes. | ||||||
| 468 | NodeT *findNearestCommonDominator(NodeT *A, NodeT *B) const { | ||||||
| 469 | assert(A && B && "Pointers are not valid")((void)0); | ||||||
| 470 | assert(A->getParent() == B->getParent() &&((void)0) | ||||||
| 471 | "Two blocks are not in same function")((void)0); | ||||||
| 472 | |||||||
| 473 | // If either A or B is a entry block then it is nearest common dominator | ||||||
| 474 | // (for forward-dominators). | ||||||
| 475 | if (!isPostDominator()) { | ||||||
| 476 | NodeT &Entry = A->getParent()->front(); | ||||||
| 477 | if (A == &Entry || B == &Entry) | ||||||
| 478 | return &Entry; | ||||||
| 479 | } | ||||||
| 480 | |||||||
| 481 | DomTreeNodeBase<NodeT> *NodeA = getNode(A); | ||||||
| 482 | DomTreeNodeBase<NodeT> *NodeB = getNode(B); | ||||||
| 483 | assert(NodeA && "A must be in the tree")((void)0); | ||||||
| 484 | assert(NodeB && "B must be in the tree")((void)0); | ||||||
| 485 | |||||||
| 486 | // Use level information to go up the tree until the levels match. Then | ||||||
| 487 | // continue going up til we arrive at the same node. | ||||||
| 488 | while (NodeA != NodeB) { | ||||||
| 489 | if (NodeA->getLevel() < NodeB->getLevel()) std::swap(NodeA, NodeB); | ||||||
| 490 | |||||||
| 491 | NodeA = NodeA->IDom; | ||||||
| 492 | } | ||||||
| 493 | |||||||
| 494 | return NodeA->getBlock(); | ||||||
| |||||||
| 495 | } | ||||||
| 496 | |||||||
| 497 | const NodeT *findNearestCommonDominator(const NodeT *A, | ||||||
| 498 | const NodeT *B) const { | ||||||
| 499 | // Cast away the const qualifiers here. This is ok since | ||||||
| 500 | // const is re-introduced on the return type. | ||||||
| 501 | return findNearestCommonDominator(const_cast<NodeT *>(A), | ||||||
| 502 | const_cast<NodeT *>(B)); | ||||||
| 503 | } | ||||||
| 504 | |||||||
| 505 | bool isVirtualRoot(const DomTreeNodeBase<NodeT> *A) const { | ||||||
| 506 | return isPostDominator() && !A->getBlock(); | ||||||
| 507 | } | ||||||
| 508 | |||||||
| 509 | //===--------------------------------------------------------------------===// | ||||||
| 510 | // API to update (Post)DominatorTree information based on modifications to | ||||||
| 511 | // the CFG... | ||||||
| 512 | |||||||
| 513 | /// Inform the dominator tree about a sequence of CFG edge insertions and | ||||||
| 514 | /// deletions and perform a batch update on the tree. | ||||||
| 515 | /// | ||||||
| 516 | /// This function should be used when there were multiple CFG updates after | ||||||
| 517 | /// the last dominator tree update. It takes care of performing the updates | ||||||
| 518 | /// in sync with the CFG and optimizes away the redundant operations that | ||||||
| 519 | /// cancel each other. | ||||||
| 520 | /// The functions expects the sequence of updates to be balanced. Eg.: | ||||||
| 521 | /// - {{Insert, A, B}, {Delete, A, B}, {Insert, A, B}} is fine, because | ||||||
| 522 | /// logically it results in a single insertions. | ||||||
| 523 | /// - {{Insert, A, B}, {Insert, A, B}} is invalid, because it doesn't make | ||||||
| 524 | /// sense to insert the same edge twice. | ||||||
| 525 | /// | ||||||
| 526 | /// What's more, the functions assumes that it's safe to ask every node in the | ||||||
| 527 | /// CFG about its children and inverse children. This implies that deletions | ||||||
| 528 | /// of CFG edges must not delete the CFG nodes before calling this function. | ||||||
| 529 | /// | ||||||
| 530 | /// The applyUpdates function can reorder the updates and remove redundant | ||||||
| 531 | /// ones internally. The batch updater is also able to detect sequences of | ||||||
| 532 | /// zero and exactly one update -- it's optimized to do less work in these | ||||||
| 533 | /// cases. | ||||||
| 534 | /// | ||||||
| 535 | /// Note that for postdominators it automatically takes care of applying | ||||||
| 536 | /// updates on reverse edges internally (so there's no need to swap the | ||||||
| 537 | /// From and To pointers when constructing DominatorTree::UpdateType). | ||||||
| 538 | /// The type of updates is the same for DomTreeBase<T> and PostDomTreeBase<T> | ||||||
| 539 | /// with the same template parameter T. | ||||||
| 540 | /// | ||||||
| 541 | /// \param Updates An unordered sequence of updates to perform. The current | ||||||
| 542 | /// CFG and the reverse of these updates provides the pre-view of the CFG. | ||||||
| 543 | /// | ||||||
| 544 | void applyUpdates(ArrayRef<UpdateType> Updates) { | ||||||
| 545 | GraphDiff<NodePtr, IsPostDominator> PreViewCFG( | ||||||
| 546 | Updates, /*ReverseApplyUpdates=*/true); | ||||||
| 547 | DomTreeBuilder::ApplyUpdates(*this, PreViewCFG, nullptr); | ||||||
| 548 | } | ||||||
| 549 | |||||||
| 550 | /// \param Updates An unordered sequence of updates to perform. The current | ||||||
| 551 | /// CFG and the reverse of these updates provides the pre-view of the CFG. | ||||||
| 552 | /// \param PostViewUpdates An unordered sequence of update to perform in order | ||||||
| 553 | /// to obtain a post-view of the CFG. The DT will be updated assuming the | ||||||
| 554 | /// obtained PostViewCFG is the desired end state. | ||||||
| 555 | void applyUpdates(ArrayRef<UpdateType> Updates, | ||||||
| 556 | ArrayRef<UpdateType> PostViewUpdates) { | ||||||
| 557 | if (Updates.empty()) { | ||||||
| 558 | GraphDiff<NodePtr, IsPostDom> PostViewCFG(PostViewUpdates); | ||||||
| 559 | DomTreeBuilder::ApplyUpdates(*this, PostViewCFG, &PostViewCFG); | ||||||
| 560 | } else { | ||||||
| 561 | // PreViewCFG needs to merge Updates and PostViewCFG. The updates in | ||||||
| 562 | // Updates need to be reversed, and match the direction in PostViewCFG. | ||||||
| 563 | // The PostViewCFG is created with updates reversed (equivalent to changes | ||||||
| 564 | // made to the CFG), so the PreViewCFG needs all the updates reverse | ||||||
| 565 | // applied. | ||||||
| 566 | SmallVector<UpdateType> AllUpdates(Updates.begin(), Updates.end()); | ||||||
| 567 | append_range(AllUpdates, PostViewUpdates); | ||||||
| 568 | GraphDiff<NodePtr, IsPostDom> PreViewCFG(AllUpdates, | ||||||
| 569 | /*ReverseApplyUpdates=*/true); | ||||||
| 570 | GraphDiff<NodePtr, IsPostDom> PostViewCFG(PostViewUpdates); | ||||||
| 571 | DomTreeBuilder::ApplyUpdates(*this, PreViewCFG, &PostViewCFG); | ||||||
| 572 | } | ||||||
| 573 | } | ||||||
| 574 | |||||||
| 575 | /// Inform the dominator tree about a CFG edge insertion and update the tree. | ||||||
| 576 | /// | ||||||
| 577 | /// This function has to be called just before or just after making the update | ||||||
| 578 | /// on the actual CFG. There cannot be any other updates that the dominator | ||||||
| 579 | /// tree doesn't know about. | ||||||
| 580 | /// | ||||||
| 581 | /// Note that for postdominators it automatically takes care of inserting | ||||||
| 582 | /// a reverse edge internally (so there's no need to swap the parameters). | ||||||
| 583 | /// | ||||||
| 584 | void insertEdge(NodeT *From, NodeT *To) { | ||||||
| 585 | assert(From)((void)0); | ||||||
| 586 | assert(To)((void)0); | ||||||
| 587 | assert(From->getParent() == Parent)((void)0); | ||||||
| 588 | assert(To->getParent() == Parent)((void)0); | ||||||
| 589 | DomTreeBuilder::InsertEdge(*this, From, To); | ||||||
| 590 | } | ||||||
| 591 | |||||||
| 592 | /// Inform the dominator tree about a CFG edge deletion and update the tree. | ||||||
| 593 | /// | ||||||
| 594 | /// This function has to be called just after making the update on the actual | ||||||
| 595 | /// CFG. An internal functions checks if the edge doesn't exist in the CFG in | ||||||
| 596 | /// DEBUG mode. There cannot be any other updates that the | ||||||
| 597 | /// dominator tree doesn't know about. | ||||||
| 598 | /// | ||||||
| 599 | /// Note that for postdominators it automatically takes care of deleting | ||||||
| 600 | /// a reverse edge internally (so there's no need to swap the parameters). | ||||||
| 601 | /// | ||||||
| 602 | void deleteEdge(NodeT *From, NodeT *To) { | ||||||
| 603 | assert(From)((void)0); | ||||||
| 604 | assert(To)((void)0); | ||||||
| 605 | assert(From->getParent() == Parent)((void)0); | ||||||
| 606 | assert(To->getParent() == Parent)((void)0); | ||||||
| 607 | DomTreeBuilder::DeleteEdge(*this, From, To); | ||||||
| 608 | } | ||||||
| 609 | |||||||
| 610 | /// Add a new node to the dominator tree information. | ||||||
| 611 | /// | ||||||
| 612 | /// This creates a new node as a child of DomBB dominator node, linking it | ||||||
| 613 | /// into the children list of the immediate dominator. | ||||||
| 614 | /// | ||||||
| 615 | /// \param BB New node in CFG. | ||||||
| 616 | /// \param DomBB CFG node that is dominator for BB. | ||||||
| 617 | /// \returns New dominator tree node that represents new CFG node. | ||||||
| 618 | /// | ||||||
| 619 | DomTreeNodeBase<NodeT> *addNewBlock(NodeT *BB, NodeT *DomBB) { | ||||||
| 620 | assert(getNode(BB) == nullptr && "Block already in dominator tree!")((void)0); | ||||||
| 621 | DomTreeNodeBase<NodeT> *IDomNode = getNode(DomBB); | ||||||
| 622 | assert(IDomNode && "Not immediate dominator specified for block!")((void)0); | ||||||
| 623 | DFSInfoValid = false; | ||||||
| 624 | return createChild(BB, IDomNode); | ||||||
| 625 | } | ||||||
| 626 | |||||||
| 627 | /// Add a new node to the forward dominator tree and make it a new root. | ||||||
| 628 | /// | ||||||
| 629 | /// \param BB New node in CFG. | ||||||
| 630 | /// \returns New dominator tree node that represents new CFG node. | ||||||
| 631 | /// | ||||||
| 632 | DomTreeNodeBase<NodeT> *setNewRoot(NodeT *BB) { | ||||||
| 633 | assert(getNode(BB) == nullptr && "Block already in dominator tree!")((void)0); | ||||||
| 634 | assert(!this->isPostDominator() &&((void)0) | ||||||
| 635 | "Cannot change root of post-dominator tree")((void)0); | ||||||
| 636 | DFSInfoValid = false; | ||||||
| 637 | DomTreeNodeBase<NodeT> *NewNode = createNode(BB); | ||||||
| 638 | if (Roots.empty()) { | ||||||
| 639 | addRoot(BB); | ||||||
| 640 | } else { | ||||||
| 641 | assert(Roots.size() == 1)((void)0); | ||||||
| 642 | NodeT *OldRoot = Roots.front(); | ||||||
| 643 | auto &OldNode = DomTreeNodes[OldRoot]; | ||||||
| 644 | OldNode = NewNode->addChild(std::move(DomTreeNodes[OldRoot])); | ||||||
| 645 | OldNode->IDom = NewNode; | ||||||
| 646 | OldNode->UpdateLevel(); | ||||||
| 647 | Roots[0] = BB; | ||||||
| 648 | } | ||||||
| 649 | return RootNode = NewNode; | ||||||
| 650 | } | ||||||
| 651 | |||||||
| 652 | /// changeImmediateDominator - This method is used to update the dominator | ||||||
| 653 | /// tree information when a node's immediate dominator changes. | ||||||
| 654 | /// | ||||||
| 655 | void changeImmediateDominator(DomTreeNodeBase<NodeT> *N, | ||||||
| 656 | DomTreeNodeBase<NodeT> *NewIDom) { | ||||||
| 657 | assert(N && NewIDom && "Cannot change null node pointers!")((void)0); | ||||||
| 658 | DFSInfoValid = false; | ||||||
| 659 | N->setIDom(NewIDom); | ||||||
| 660 | } | ||||||
| 661 | |||||||
| 662 | void changeImmediateDominator(NodeT *BB, NodeT *NewBB) { | ||||||
| 663 | changeImmediateDominator(getNode(BB), getNode(NewBB)); | ||||||
| 664 | } | ||||||
| 665 | |||||||
| 666 | /// eraseNode - Removes a node from the dominator tree. Block must not | ||||||
| 667 | /// dominate any other blocks. Removes node from its immediate dominator's | ||||||
| 668 | /// children list. Deletes dominator node associated with basic block BB. | ||||||
| 669 | void eraseNode(NodeT *BB) { | ||||||
| 670 | DomTreeNodeBase<NodeT> *Node = getNode(BB); | ||||||
| 671 | assert(Node && "Removing node that isn't in dominator tree.")((void)0); | ||||||
| 672 | assert(Node->isLeaf() && "Node is not a leaf node.")((void)0); | ||||||
| 673 | |||||||
| 674 | DFSInfoValid = false; | ||||||
| 675 | |||||||
| 676 | // Remove node from immediate dominator's children list. | ||||||
| 677 | DomTreeNodeBase<NodeT> *IDom = Node->getIDom(); | ||||||
| 678 | if (IDom) { | ||||||
| 679 | const auto I = find(IDom->Children, Node); | ||||||
| 680 | assert(I != IDom->Children.end() &&((void)0) | ||||||
| 681 | "Not in immediate dominator children set!")((void)0); | ||||||
| 682 | // I am no longer your child... | ||||||
| 683 | IDom->Children.erase(I); | ||||||
| 684 | } | ||||||
| 685 | |||||||
| 686 | DomTreeNodes.erase(BB); | ||||||
| 687 | |||||||
| 688 | if (!IsPostDom) return; | ||||||
| 689 | |||||||
| 690 | // Remember to update PostDominatorTree roots. | ||||||
| 691 | auto RIt = llvm::find(Roots, BB); | ||||||
| 692 | if (RIt != Roots.end()) { | ||||||
| 693 | std::swap(*RIt, Roots.back()); | ||||||
| 694 | Roots.pop_back(); | ||||||
| 695 | } | ||||||
| 696 | } | ||||||
| 697 | |||||||
| 698 | /// splitBlock - BB is split and now it has one successor. Update dominator | ||||||
| 699 | /// tree to reflect this change. | ||||||
| 700 | void splitBlock(NodeT *NewBB) { | ||||||
| 701 | if (IsPostDominator
| ||||||
| 702 | Split<Inverse<NodeT *>>(NewBB); | ||||||
| 703 | else | ||||||
| 704 | Split<NodeT *>(NewBB); | ||||||
| 705 | } | ||||||
| 706 | |||||||
| 707 | /// print - Convert to human readable form | ||||||
| 708 | /// | ||||||
| 709 | void print(raw_ostream &O) const { | ||||||
| 710 | O << "=============================--------------------------------\n"; | ||||||
| 711 | if (IsPostDominator) | ||||||
| 712 | O << "Inorder PostDominator Tree: "; | ||||||
| 713 | else | ||||||
| 714 | O << "Inorder Dominator Tree: "; | ||||||
| 715 | if (!DFSInfoValid) | ||||||
| 716 | O << "DFSNumbers invalid: " << SlowQueries << " slow queries."; | ||||||
| 717 | O << "\n"; | ||||||
| 718 | |||||||
| 719 | // The postdom tree can have a null root if there are no returns. | ||||||
| 720 | if (getRootNode()) PrintDomTree<NodeT>(getRootNode(), O, 1); | ||||||
| 721 | O << "Roots: "; | ||||||
| 722 | for (const NodePtr Block : Roots) { | ||||||
| 723 | Block->printAsOperand(O, false); | ||||||
| 724 | O << " "; | ||||||
| 725 | } | ||||||
| 726 | O << "\n"; | ||||||
| 727 | } | ||||||
| 728 | |||||||
| 729 | public: | ||||||
| 730 | /// updateDFSNumbers - Assign In and Out numbers to the nodes while walking | ||||||
| 731 | /// dominator tree in dfs order. | ||||||
| 732 | void updateDFSNumbers() const { | ||||||
| 733 | if (DFSInfoValid) { | ||||||
| 734 | SlowQueries = 0; | ||||||
| 735 | return; | ||||||
| 736 | } | ||||||
| 737 | |||||||
| 738 | SmallVector<std::pair<const DomTreeNodeBase<NodeT> *, | ||||||
| 739 | typename DomTreeNodeBase<NodeT>::const_iterator>, | ||||||
| 740 | 32> WorkStack; | ||||||
| 741 | |||||||
| 742 | const DomTreeNodeBase<NodeT> *ThisRoot = getRootNode(); | ||||||
| 743 | assert((!Parent || ThisRoot) && "Empty constructed DomTree")((void)0); | ||||||
| 744 | if (!ThisRoot) | ||||||
| 745 | return; | ||||||
| 746 | |||||||
| 747 | // Both dominators and postdominators have a single root node. In the case | ||||||
| 748 | // case of PostDominatorTree, this node is a virtual root. | ||||||
| 749 | WorkStack.push_back({ThisRoot, ThisRoot->begin()}); | ||||||
| 750 | |||||||
| 751 | unsigned DFSNum = 0; | ||||||
| 752 | ThisRoot->DFSNumIn = DFSNum++; | ||||||
| 753 | |||||||
| 754 | while (!WorkStack.empty()) { | ||||||
| 755 | const DomTreeNodeBase<NodeT> *Node = WorkStack.back().first; | ||||||
| 756 | const auto ChildIt = WorkStack.back().second; | ||||||
| 757 | |||||||
| 758 | // If we visited all of the children of this node, "recurse" back up the | ||||||
| 759 | // stack setting the DFOutNum. | ||||||
| 760 | if (ChildIt == Node->end()) { | ||||||
| 761 | Node->DFSNumOut = DFSNum++; | ||||||
| 762 | WorkStack.pop_back(); | ||||||
| 763 | } else { | ||||||
| 764 | // Otherwise, recursively visit this child. | ||||||
| 765 | const DomTreeNodeBase<NodeT> *Child = *ChildIt; | ||||||
| 766 | ++WorkStack.back().second; | ||||||
| 767 | |||||||
| 768 | WorkStack.push_back({Child, Child->begin()}); | ||||||
| 769 | Child->DFSNumIn = DFSNum++; | ||||||
| 770 | } | ||||||
| 771 | } | ||||||
| 772 | |||||||
| 773 | SlowQueries = 0; | ||||||
| 774 | DFSInfoValid = true; | ||||||
| 775 | } | ||||||
| 776 | |||||||
| 777 | /// recalculate - compute a dominator tree for the given function | ||||||
| 778 | void recalculate(ParentType &Func) { | ||||||
| 779 | Parent = &Func; | ||||||
| 780 | DomTreeBuilder::Calculate(*this); | ||||||
| 781 | } | ||||||
| 782 | |||||||
| 783 | void recalculate(ParentType &Func, ArrayRef<UpdateType> Updates) { | ||||||
| 784 | Parent = &Func; | ||||||
| 785 | DomTreeBuilder::CalculateWithUpdates(*this, Updates); | ||||||
| 786 | } | ||||||
| 787 | |||||||
| 788 | /// verify - checks if the tree is correct. There are 3 level of verification: | ||||||
| 789 | /// - Full -- verifies if the tree is correct by making sure all the | ||||||
| 790 | /// properties (including the parent and the sibling property) | ||||||
| 791 | /// hold. | ||||||
| 792 | /// Takes O(N^3) time. | ||||||
| 793 | /// | ||||||
| 794 | /// - Basic -- checks if the tree is correct, but compares it to a freshly | ||||||
| 795 | /// constructed tree instead of checking the sibling property. | ||||||
| 796 | /// Takes O(N^2) time. | ||||||
| 797 | /// | ||||||
| 798 | /// - Fast -- checks basic tree structure and compares it with a freshly | ||||||
| 799 | /// constructed tree. | ||||||
| 800 | /// Takes O(N^2) time worst case, but is faster in practise (same | ||||||
| 801 | /// as tree construction). | ||||||
| 802 | bool verify(VerificationLevel VL = VerificationLevel::Full) const { | ||||||
| 803 | return DomTreeBuilder::Verify(*this, VL); | ||||||
| 804 | } | ||||||
| 805 | |||||||
| 806 | void reset() { | ||||||
| 807 | DomTreeNodes.clear(); | ||||||
| 808 | Roots.clear(); | ||||||
| 809 | RootNode = nullptr; | ||||||
| 810 | Parent = nullptr; | ||||||
| 811 | DFSInfoValid = false; | ||||||
| 812 | SlowQueries = 0; | ||||||
| 813 | } | ||||||
| 814 | |||||||
| 815 | protected: | ||||||
| 816 | void addRoot(NodeT *BB) { this->Roots.push_back(BB); } | ||||||
| 817 | |||||||
| 818 | DomTreeNodeBase<NodeT> *createChild(NodeT *BB, DomTreeNodeBase<NodeT> *IDom) { | ||||||
| 819 | return (DomTreeNodes[BB] = IDom->addChild( | ||||||
| 820 | std::make_unique<DomTreeNodeBase<NodeT>>(BB, IDom))) | ||||||
| 821 | .get(); | ||||||
| 822 | } | ||||||
| 823 | |||||||
| 824 | DomTreeNodeBase<NodeT> *createNode(NodeT *BB) { | ||||||
| 825 | return (DomTreeNodes[BB] = | ||||||
| 826 | std::make_unique<DomTreeNodeBase<NodeT>>(BB, nullptr)) | ||||||
| 827 | .get(); | ||||||
| 828 | } | ||||||
| 829 | |||||||
| 830 | // NewBB is split and now it has one successor. Update dominator tree to | ||||||
| 831 | // reflect this change. | ||||||
| 832 | template <class N> | ||||||
| 833 | void Split(typename GraphTraits<N>::NodeRef NewBB) { | ||||||
| 834 | using GraphT = GraphTraits<N>; | ||||||
| 835 | using NodeRef = typename GraphT::NodeRef; | ||||||
| 836 | assert(std::distance(GraphT::child_begin(NewBB),((void)0) | ||||||
| 837 | GraphT::child_end(NewBB)) == 1 &&((void)0) | ||||||
| 838 | "NewBB should have a single successor!")((void)0); | ||||||
| 839 | NodeRef NewBBSucc = *GraphT::child_begin(NewBB); | ||||||
| 840 | |||||||
| 841 | SmallVector<NodeRef, 4> PredBlocks(children<Inverse<N>>(NewBB)); | ||||||
| 842 | |||||||
| 843 | assert(!PredBlocks.empty() && "No predblocks?")((void)0); | ||||||
| 844 | |||||||
| 845 | bool NewBBDominatesNewBBSucc = true; | ||||||
| 846 | for (auto Pred : children<Inverse<N>>(NewBBSucc)) { | ||||||
| 847 | if (Pred != NewBB && !dominates(NewBBSucc, Pred) && | ||||||
| 848 | isReachableFromEntry(Pred)) { | ||||||
| 849 | NewBBDominatesNewBBSucc = false; | ||||||
| 850 | break; | ||||||
| 851 | } | ||||||
| 852 | } | ||||||
| 853 | |||||||
| 854 | // Find NewBB's immediate dominator and create new dominator tree node for | ||||||
| 855 | // NewBB. | ||||||
| 856 | NodeT *NewBBIDom = nullptr; | ||||||
| 857 | unsigned i = 0; | ||||||
| 858 | for (i = 0; i < PredBlocks.size(); ++i) | ||||||
| 859 | if (isReachableFromEntry(PredBlocks[i])) { | ||||||
| 860 | NewBBIDom = PredBlocks[i]; | ||||||
| 861 | break; | ||||||
| 862 | } | ||||||
| 863 | |||||||
| 864 | // It's possible that none of the predecessors of NewBB are reachable; | ||||||
| 865 | // in that case, NewBB itself is unreachable, so nothing needs to be | ||||||
| 866 | // changed. | ||||||
| 867 | if (!NewBBIDom) return; | ||||||
| 868 | |||||||
| 869 | for (i = i + 1; i < PredBlocks.size(); ++i) { | ||||||
| 870 | if (isReachableFromEntry(PredBlocks[i])) | ||||||
| 871 | NewBBIDom = findNearestCommonDominator(NewBBIDom, PredBlocks[i]); | ||||||
| 872 | } | ||||||
| 873 | |||||||
| 874 | // Create the new dominator tree node... and set the idom of NewBB. | ||||||
| 875 | DomTreeNodeBase<NodeT> *NewBBNode = addNewBlock(NewBB, NewBBIDom); | ||||||
| 876 | |||||||
| 877 | // If NewBB strictly dominates other blocks, then it is now the immediate | ||||||
| 878 | // dominator of NewBBSucc. Update the dominator tree as appropriate. | ||||||
| 879 | if (NewBBDominatesNewBBSucc) { | ||||||
| 880 | DomTreeNodeBase<NodeT> *NewBBSuccNode = getNode(NewBBSucc); | ||||||
| 881 | changeImmediateDominator(NewBBSuccNode, NewBBNode); | ||||||
| 882 | } | ||||||
| 883 | } | ||||||
| 884 | |||||||
| 885 | private: | ||||||
| 886 | bool dominatedBySlowTreeWalk(const DomTreeNodeBase<NodeT> *A, | ||||||
| 887 | const DomTreeNodeBase<NodeT> *B) const { | ||||||
| 888 | assert(A != B)((void)0); | ||||||
| 889 | assert(isReachableFromEntry(B))((void)0); | ||||||
| 890 | assert(isReachableFromEntry(A))((void)0); | ||||||
| 891 | |||||||
| 892 | const unsigned ALevel = A->getLevel(); | ||||||
| 893 | const DomTreeNodeBase<NodeT> *IDom; | ||||||
| 894 | |||||||
| 895 | // Don't walk nodes above A's subtree. When we reach A's level, we must | ||||||
| 896 | // either find A or be in some other subtree not dominated by A. | ||||||
| 897 | while ((IDom = B->getIDom()) != nullptr && IDom->getLevel() >= ALevel) | ||||||
| 898 | B = IDom; // Walk up the tree | ||||||
| 899 | |||||||
| 900 | return B == A; | ||||||
| 901 | } | ||||||
| 902 | |||||||
| 903 | /// Wipe this tree's state without releasing any resources. | ||||||
| 904 | /// | ||||||
| 905 | /// This is essentially a post-move helper only. It leaves the object in an | ||||||
| 906 | /// assignable and destroyable state, but otherwise invalid. | ||||||
| 907 | void wipe() { | ||||||
| 908 | DomTreeNodes.clear(); | ||||||
| 909 | RootNode = nullptr; | ||||||
| 910 | Parent = nullptr; | ||||||
| 911 | } | ||||||
| 912 | }; | ||||||
| 913 | |||||||
| 914 | template <typename T> | ||||||
| 915 | using DomTreeBase = DominatorTreeBase<T, false>; | ||||||
| 916 | |||||||
| 917 | template <typename T> | ||||||
| 918 | using PostDomTreeBase = DominatorTreeBase<T, true>; | ||||||
| 919 | |||||||
| 920 | // These two functions are declared out of line as a workaround for building | ||||||
| 921 | // with old (< r147295) versions of clang because of pr11642. | ||||||
| 922 | template <typename NodeT, bool IsPostDom> | ||||||
| 923 | bool DominatorTreeBase<NodeT, IsPostDom>::dominates(const NodeT *A, | ||||||
| 924 | const NodeT *B) const { | ||||||
| 925 | if (A == B) | ||||||
| 926 | return true; | ||||||
| 927 | |||||||
| 928 | // Cast away the const qualifiers here. This is ok since | ||||||
| 929 | // this function doesn't actually return the values returned | ||||||
| 930 | // from getNode. | ||||||
| 931 | return dominates(getNode(const_cast<NodeT *>(A)), | ||||||
| 932 | getNode(const_cast<NodeT *>(B))); | ||||||
| 933 | } | ||||||
| 934 | template <typename NodeT, bool IsPostDom> | ||||||
| 935 | bool DominatorTreeBase<NodeT, IsPostDom>::properlyDominates( | ||||||
| 936 | const NodeT *A, const NodeT *B) const { | ||||||
| 937 | if (A == B) | ||||||
| 938 | return false; | ||||||
| 939 | |||||||
| 940 | // Cast away the const qualifiers here. This is ok since | ||||||
| 941 | // this function doesn't actually return the values returned | ||||||
| 942 | // from getNode. | ||||||
| 943 | return dominates(getNode(const_cast<NodeT *>(A)), | ||||||
| 944 | getNode(const_cast<NodeT *>(B))); | ||||||
| 945 | } | ||||||
| 946 | |||||||
| 947 | } // end namespace llvm | ||||||
| 948 | |||||||
| 949 | #endif // LLVM_SUPPORT_GENERICDOMTREE_H |
| 1 | //===- llvm/ADT/DenseMap.h - Dense probed hash table ------------*- C++ -*-===// |
| 2 | // |
| 3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| 4 | // See https://llvm.org/LICENSE.txt for license information. |
| 5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| 6 | // |
| 7 | //===----------------------------------------------------------------------===// |
| 8 | // |
| 9 | // This file defines the DenseMap class. |
| 10 | // |
| 11 | //===----------------------------------------------------------------------===// |
| 12 | |
| 13 | #ifndef LLVM_ADT_DENSEMAP_H |
| 14 | #define LLVM_ADT_DENSEMAP_H |
| 15 | |
| 16 | #include "llvm/ADT/DenseMapInfo.h" |
| 17 | #include "llvm/ADT/EpochTracker.h" |
| 18 | #include "llvm/Support/AlignOf.h" |
| 19 | #include "llvm/Support/Compiler.h" |
| 20 | #include "llvm/Support/MathExtras.h" |
| 21 | #include "llvm/Support/MemAlloc.h" |
| 22 | #include "llvm/Support/ReverseIteration.h" |
| 23 | #include "llvm/Support/type_traits.h" |
| 24 | #include <algorithm> |
| 25 | #include <cassert> |
| 26 | #include <cstddef> |
| 27 | #include <cstring> |
| 28 | #include <initializer_list> |
| 29 | #include <iterator> |
| 30 | #include <new> |
| 31 | #include <type_traits> |
| 32 | #include <utility> |
| 33 | |
| 34 | namespace llvm { |
| 35 | |
| 36 | namespace detail { |
| 37 | |
| 38 | // We extend a pair to allow users to override the bucket type with their own |
| 39 | // implementation without requiring two members. |
| 40 | template <typename KeyT, typename ValueT> |
| 41 | struct DenseMapPair : public std::pair<KeyT, ValueT> { |
| 42 | using std::pair<KeyT, ValueT>::pair; |
| 43 | |
| 44 | KeyT &getFirst() { return std::pair<KeyT, ValueT>::first; } |
| 45 | const KeyT &getFirst() const { return std::pair<KeyT, ValueT>::first; } |
| 46 | ValueT &getSecond() { return std::pair<KeyT, ValueT>::second; } |
| 47 | const ValueT &getSecond() const { return std::pair<KeyT, ValueT>::second; } |
| 48 | }; |
| 49 | |
| 50 | } // end namespace detail |
| 51 | |
| 52 | template <typename KeyT, typename ValueT, |
| 53 | typename KeyInfoT = DenseMapInfo<KeyT>, |
| 54 | typename Bucket = llvm::detail::DenseMapPair<KeyT, ValueT>, |
| 55 | bool IsConst = false> |
| 56 | class DenseMapIterator; |
| 57 | |
| 58 | template <typename DerivedT, typename KeyT, typename ValueT, typename KeyInfoT, |
| 59 | typename BucketT> |
| 60 | class DenseMapBase : public DebugEpochBase { |
| 61 | template <typename T> |
| 62 | using const_arg_type_t = typename const_pointer_or_const_ref<T>::type; |
| 63 | |
| 64 | public: |
| 65 | using size_type = unsigned; |
| 66 | using key_type = KeyT; |
| 67 | using mapped_type = ValueT; |
| 68 | using value_type = BucketT; |
| 69 | |
| 70 | using iterator = DenseMapIterator<KeyT, ValueT, KeyInfoT, BucketT>; |
| 71 | using const_iterator = |
| 72 | DenseMapIterator<KeyT, ValueT, KeyInfoT, BucketT, true>; |
| 73 | |
| 74 | inline iterator begin() { |
| 75 | // When the map is empty, avoid the overhead of advancing/retreating past |
| 76 | // empty buckets. |
| 77 | if (empty()) |
| 78 | return end(); |
| 79 | if (shouldReverseIterate<KeyT>()) |
| 80 | return makeIterator(getBucketsEnd() - 1, getBuckets(), *this); |
| 81 | return makeIterator(getBuckets(), getBucketsEnd(), *this); |
| 82 | } |
| 83 | inline iterator end() { |
| 84 | return makeIterator(getBucketsEnd(), getBucketsEnd(), *this, true); |
| 85 | } |
| 86 | inline const_iterator begin() const { |
| 87 | if (empty()) |
| 88 | return end(); |
| 89 | if (shouldReverseIterate<KeyT>()) |
| 90 | return makeConstIterator(getBucketsEnd() - 1, getBuckets(), *this); |
| 91 | return makeConstIterator(getBuckets(), getBucketsEnd(), *this); |
| 92 | } |
| 93 | inline const_iterator end() const { |
| 94 | return makeConstIterator(getBucketsEnd(), getBucketsEnd(), *this, true); |
| 95 | } |
| 96 | |
| 97 | LLVM_NODISCARD[[clang::warn_unused_result]] bool empty() const { |
| 98 | return getNumEntries() == 0; |
| 99 | } |
| 100 | unsigned size() const { return getNumEntries(); } |
| 101 | |
| 102 | /// Grow the densemap so that it can contain at least \p NumEntries items |
| 103 | /// before resizing again. |
| 104 | void reserve(size_type NumEntries) { |
| 105 | auto NumBuckets = getMinBucketToReserveForEntries(NumEntries); |
| 106 | incrementEpoch(); |
| 107 | if (NumBuckets > getNumBuckets()) |
| 108 | grow(NumBuckets); |
| 109 | } |
| 110 | |
| 111 | void clear() { |
| 112 | incrementEpoch(); |
| 113 | if (getNumEntries() == 0 && getNumTombstones() == 0) return; |
| 114 | |
| 115 | // If the capacity of the array is huge, and the # elements used is small, |
| 116 | // shrink the array. |
| 117 | if (getNumEntries() * 4 < getNumBuckets() && getNumBuckets() > 64) { |
| 118 | shrink_and_clear(); |
| 119 | return; |
| 120 | } |
| 121 | |
| 122 | const KeyT EmptyKey = getEmptyKey(), TombstoneKey = getTombstoneKey(); |
| 123 | if (std::is_trivially_destructible<ValueT>::value) { |
| 124 | // Use a simpler loop when values don't need destruction. |
| 125 | for (BucketT *P = getBuckets(), *E = getBucketsEnd(); P != E; ++P) |
| 126 | P->getFirst() = EmptyKey; |
| 127 | } else { |
| 128 | unsigned NumEntries = getNumEntries(); |
| 129 | for (BucketT *P = getBuckets(), *E = getBucketsEnd(); P != E; ++P) { |
| 130 | if (!KeyInfoT::isEqual(P->getFirst(), EmptyKey)) { |
| 131 | if (!KeyInfoT::isEqual(P->getFirst(), TombstoneKey)) { |
| 132 | P->getSecond().~ValueT(); |
| 133 | --NumEntries; |
| 134 | } |
| 135 | P->getFirst() = EmptyKey; |
| 136 | } |
| 137 | } |
| 138 | assert(NumEntries == 0 && "Node count imbalance!")((void)0); |
| 139 | } |
| 140 | setNumEntries(0); |
| 141 | setNumTombstones(0); |
| 142 | } |
| 143 | |
| 144 | /// Return 1 if the specified key is in the map, 0 otherwise. |
| 145 | size_type count(const_arg_type_t<KeyT> Val) const { |
| 146 | const BucketT *TheBucket; |
| 147 | return LookupBucketFor(Val, TheBucket) ? 1 : 0; |
| 148 | } |
| 149 | |
| 150 | iterator find(const_arg_type_t<KeyT> Val) { |
| 151 | BucketT *TheBucket; |
| 152 | if (LookupBucketFor(Val, TheBucket)) |
| 153 | return makeIterator(TheBucket, |
| 154 | shouldReverseIterate<KeyT>() ? getBuckets() |
| 155 | : getBucketsEnd(), |
| 156 | *this, true); |
| 157 | return end(); |
| 158 | } |
| 159 | const_iterator find(const_arg_type_t<KeyT> Val) const { |
| 160 | const BucketT *TheBucket; |
| 161 | if (LookupBucketFor(Val, TheBucket)) |
| 162 | return makeConstIterator(TheBucket, |
| 163 | shouldReverseIterate<KeyT>() ? getBuckets() |
| 164 | : getBucketsEnd(), |
| 165 | *this, true); |
| 166 | return end(); |
| 167 | } |
| 168 | |
| 169 | /// Alternate version of find() which allows a different, and possibly |
| 170 | /// less expensive, key type. |
| 171 | /// The DenseMapInfo is responsible for supplying methods |
| 172 | /// getHashValue(LookupKeyT) and isEqual(LookupKeyT, KeyT) for each key |
| 173 | /// type used. |
| 174 | template<class LookupKeyT> |
| 175 | iterator find_as(const LookupKeyT &Val) { |
| 176 | BucketT *TheBucket; |
| 177 | if (LookupBucketFor(Val, TheBucket)) |
| 178 | return makeIterator(TheBucket, |
| 179 | shouldReverseIterate<KeyT>() ? getBuckets() |
| 180 | : getBucketsEnd(), |
| 181 | *this, true); |
| 182 | return end(); |
| 183 | } |
| 184 | template<class LookupKeyT> |
| 185 | const_iterator find_as(const LookupKeyT &Val) const { |
| 186 | const BucketT *TheBucket; |
| 187 | if (LookupBucketFor(Val, TheBucket)) |
| 188 | return makeConstIterator(TheBucket, |
| 189 | shouldReverseIterate<KeyT>() ? getBuckets() |
| 190 | : getBucketsEnd(), |
| 191 | *this, true); |
| 192 | return end(); |
| 193 | } |
| 194 | |
| 195 | /// lookup - Return the entry for the specified key, or a default |
| 196 | /// constructed value if no such entry exists. |
| 197 | ValueT lookup(const_arg_type_t<KeyT> Val) const { |
| 198 | const BucketT *TheBucket; |
| 199 | if (LookupBucketFor(Val, TheBucket)) |
| 200 | return TheBucket->getSecond(); |
| 201 | return ValueT(); |
| 202 | } |
| 203 | |
| 204 | // Inserts key,value pair into the map if the key isn't already in the map. |
| 205 | // If the key is already in the map, it returns false and doesn't update the |
| 206 | // value. |
| 207 | std::pair<iterator, bool> insert(const std::pair<KeyT, ValueT> &KV) { |
| 208 | return try_emplace(KV.first, KV.second); |
| 209 | } |
| 210 | |
| 211 | // Inserts key,value pair into the map if the key isn't already in the map. |
| 212 | // If the key is already in the map, it returns false and doesn't update the |
| 213 | // value. |
| 214 | std::pair<iterator, bool> insert(std::pair<KeyT, ValueT> &&KV) { |
| 215 | return try_emplace(std::move(KV.first), std::move(KV.second)); |
| 216 | } |
| 217 | |
| 218 | // Inserts key,value pair into the map if the key isn't already in the map. |
| 219 | // The value is constructed in-place if the key is not in the map, otherwise |
| 220 | // it is not moved. |
| 221 | template <typename... Ts> |
| 222 | std::pair<iterator, bool> try_emplace(KeyT &&Key, Ts &&... Args) { |
| 223 | BucketT *TheBucket; |
| 224 | if (LookupBucketFor(Key, TheBucket)) |
| 225 | return std::make_pair(makeIterator(TheBucket, |
| 226 | shouldReverseIterate<KeyT>() |
| 227 | ? getBuckets() |
| 228 | : getBucketsEnd(), |
| 229 | *this, true), |
| 230 | false); // Already in map. |
| 231 | |
| 232 | // Otherwise, insert the new element. |
| 233 | TheBucket = |
| 234 | InsertIntoBucket(TheBucket, std::move(Key), std::forward<Ts>(Args)...); |
| 235 | return std::make_pair(makeIterator(TheBucket, |
| 236 | shouldReverseIterate<KeyT>() |
| 237 | ? getBuckets() |
| 238 | : getBucketsEnd(), |
| 239 | *this, true), |
| 240 | true); |
| 241 | } |
| 242 | |
| 243 | // Inserts key,value pair into the map if the key isn't already in the map. |
| 244 | // The value is constructed in-place if the key is not in the map, otherwise |
| 245 | // it is not moved. |
| 246 | template <typename... Ts> |
| 247 | std::pair<iterator, bool> try_emplace(const KeyT &Key, Ts &&... Args) { |
| 248 | BucketT *TheBucket; |
| 249 | if (LookupBucketFor(Key, TheBucket)) |
| 250 | return std::make_pair(makeIterator(TheBucket, |
| 251 | shouldReverseIterate<KeyT>() |
| 252 | ? getBuckets() |
| 253 | : getBucketsEnd(), |
| 254 | *this, true), |
| 255 | false); // Already in map. |
| 256 | |
| 257 | // Otherwise, insert the new element. |
| 258 | TheBucket = InsertIntoBucket(TheBucket, Key, std::forward<Ts>(Args)...); |
| 259 | return std::make_pair(makeIterator(TheBucket, |
| 260 | shouldReverseIterate<KeyT>() |
| 261 | ? getBuckets() |
| 262 | : getBucketsEnd(), |
| 263 | *this, true), |
| 264 | true); |
| 265 | } |
| 266 | |
| 267 | /// Alternate version of insert() which allows a different, and possibly |
| 268 | /// less expensive, key type. |
| 269 | /// The DenseMapInfo is responsible for supplying methods |
| 270 | /// getHashValue(LookupKeyT) and isEqual(LookupKeyT, KeyT) for each key |
| 271 | /// type used. |
| 272 | template <typename LookupKeyT> |
| 273 | std::pair<iterator, bool> insert_as(std::pair<KeyT, ValueT> &&KV, |
| 274 | const LookupKeyT &Val) { |
| 275 | BucketT *TheBucket; |
| 276 | if (LookupBucketFor(Val, TheBucket)) |
| 277 | return std::make_pair(makeIterator(TheBucket, |
| 278 | shouldReverseIterate<KeyT>() |
| 279 | ? getBuckets() |
| 280 | : getBucketsEnd(), |
| 281 | *this, true), |
| 282 | false); // Already in map. |
| 283 | |
| 284 | // Otherwise, insert the new element. |
| 285 | TheBucket = InsertIntoBucketWithLookup(TheBucket, std::move(KV.first), |
| 286 | std::move(KV.second), Val); |
| 287 | return std::make_pair(makeIterator(TheBucket, |
| 288 | shouldReverseIterate<KeyT>() |
| 289 | ? getBuckets() |
| 290 | : getBucketsEnd(), |
| 291 | *this, true), |
| 292 | true); |
| 293 | } |
| 294 | |
| 295 | /// insert - Range insertion of pairs. |
| 296 | template<typename InputIt> |
| 297 | void insert(InputIt I, InputIt E) { |
| 298 | for (; I != E; ++I) |
| 299 | insert(*I); |
| 300 | } |
| 301 | |
| 302 | bool erase(const KeyT &Val) { |
| 303 | BucketT *TheBucket; |
| 304 | if (!LookupBucketFor(Val, TheBucket)) |
| 305 | return false; // not in map. |
| 306 | |
| 307 | TheBucket->getSecond().~ValueT(); |
| 308 | TheBucket->getFirst() = getTombstoneKey(); |
| 309 | decrementNumEntries(); |
| 310 | incrementNumTombstones(); |
| 311 | return true; |
| 312 | } |
| 313 | void erase(iterator I) { |
| 314 | BucketT *TheBucket = &*I; |
| 315 | TheBucket->getSecond().~ValueT(); |
| 316 | TheBucket->getFirst() = getTombstoneKey(); |
| 317 | decrementNumEntries(); |
| 318 | incrementNumTombstones(); |
| 319 | } |
| 320 | |
| 321 | value_type& FindAndConstruct(const KeyT &Key) { |
| 322 | BucketT *TheBucket; |
| 323 | if (LookupBucketFor(Key, TheBucket)) |
| 324 | return *TheBucket; |
| 325 | |
| 326 | return *InsertIntoBucket(TheBucket, Key); |
| 327 | } |
| 328 | |
| 329 | ValueT &operator[](const KeyT &Key) { |
| 330 | return FindAndConstruct(Key).second; |
| 331 | } |
| 332 | |
| 333 | value_type& FindAndConstruct(KeyT &&Key) { |
| 334 | BucketT *TheBucket; |
| 335 | if (LookupBucketFor(Key, TheBucket)) |
| 336 | return *TheBucket; |
| 337 | |
| 338 | return *InsertIntoBucket(TheBucket, std::move(Key)); |
| 339 | } |
| 340 | |
| 341 | ValueT &operator[](KeyT &&Key) { |
| 342 | return FindAndConstruct(std::move(Key)).second; |
| 343 | } |
| 344 | |
| 345 | /// isPointerIntoBucketsArray - Return true if the specified pointer points |
| 346 | /// somewhere into the DenseMap's array of buckets (i.e. either to a key or |
| 347 | /// value in the DenseMap). |
| 348 | bool isPointerIntoBucketsArray(const void *Ptr) const { |
| 349 | return Ptr >= getBuckets() && Ptr < getBucketsEnd(); |
| 350 | } |
| 351 | |
| 352 | /// getPointerIntoBucketsArray() - Return an opaque pointer into the buckets |
| 353 | /// array. In conjunction with the previous method, this can be used to |
| 354 | /// determine whether an insertion caused the DenseMap to reallocate. |
| 355 | const void *getPointerIntoBucketsArray() const { return getBuckets(); } |
| 356 | |
| 357 | protected: |
| 358 | DenseMapBase() = default; |
| 359 | |
| 360 | void destroyAll() { |
| 361 | if (getNumBuckets() == 0) // Nothing to do. |
| 362 | return; |
| 363 | |
| 364 | const KeyT EmptyKey = getEmptyKey(), TombstoneKey = getTombstoneKey(); |
| 365 | for (BucketT *P = getBuckets(), *E = getBucketsEnd(); P != E; ++P) { |
| 366 | if (!KeyInfoT::isEqual(P->getFirst(), EmptyKey) && |
| 367 | !KeyInfoT::isEqual(P->getFirst(), TombstoneKey)) |
| 368 | P->getSecond().~ValueT(); |
| 369 | P->getFirst().~KeyT(); |
| 370 | } |
| 371 | } |
| 372 | |
| 373 | void initEmpty() { |
| 374 | setNumEntries(0); |
| 375 | setNumTombstones(0); |
| 376 | |
| 377 | assert((getNumBuckets() & (getNumBuckets()-1)) == 0 &&((void)0) |
| 378 | "# initial buckets must be a power of two!")((void)0); |
| 379 | const KeyT EmptyKey = getEmptyKey(); |
| 380 | for (BucketT *B = getBuckets(), *E = getBucketsEnd(); B != E; ++B) |
| 381 | ::new (&B->getFirst()) KeyT(EmptyKey); |
| 382 | } |
| 383 | |
| 384 | /// Returns the number of buckets to allocate to ensure that the DenseMap can |
| 385 | /// accommodate \p NumEntries without need to grow(). |
| 386 | unsigned getMinBucketToReserveForEntries(unsigned NumEntries) { |
| 387 | // Ensure that "NumEntries * 4 < NumBuckets * 3" |
| 388 | if (NumEntries == 0) |
| 389 | return 0; |
| 390 | // +1 is required because of the strict equality. |
| 391 | // For example if NumEntries is 48, we need to return 401. |
| 392 | return NextPowerOf2(NumEntries * 4 / 3 + 1); |
| 393 | } |
| 394 | |
| 395 | void moveFromOldBuckets(BucketT *OldBucketsBegin, BucketT *OldBucketsEnd) { |
| 396 | initEmpty(); |
| 397 | |
| 398 | // Insert all the old elements. |
| 399 | const KeyT EmptyKey = getEmptyKey(); |
| 400 | const KeyT TombstoneKey = getTombstoneKey(); |
| 401 | for (BucketT *B = OldBucketsBegin, *E = OldBucketsEnd; B != E; ++B) { |
| 402 | if (!KeyInfoT::isEqual(B->getFirst(), EmptyKey) && |
| 403 | !KeyInfoT::isEqual(B->getFirst(), TombstoneKey)) { |
| 404 | // Insert the key/value into the new table. |
| 405 | BucketT *DestBucket; |
| 406 | bool FoundVal = LookupBucketFor(B->getFirst(), DestBucket); |
| 407 | (void)FoundVal; // silence warning. |
| 408 | assert(!FoundVal && "Key already in new map?")((void)0); |
| 409 | DestBucket->getFirst() = std::move(B->getFirst()); |
| 410 | ::new (&DestBucket->getSecond()) ValueT(std::move(B->getSecond())); |
| 411 | incrementNumEntries(); |
| 412 | |
| 413 | // Free the value. |
| 414 | B->getSecond().~ValueT(); |
| 415 | } |
| 416 | B->getFirst().~KeyT(); |
| 417 | } |
| 418 | } |
| 419 | |
| 420 | template <typename OtherBaseT> |
| 421 | void copyFrom( |
| 422 | const DenseMapBase<OtherBaseT, KeyT, ValueT, KeyInfoT, BucketT> &other) { |
| 423 | assert(&other != this)((void)0); |
| 424 | assert(getNumBuckets() == other.getNumBuckets())((void)0); |
| 425 | |
| 426 | setNumEntries(other.getNumEntries()); |
| 427 | setNumTombstones(other.getNumTombstones()); |
| 428 | |
| 429 | if (std::is_trivially_copyable<KeyT>::value && |
| 430 | std::is_trivially_copyable<ValueT>::value) |
| 431 | memcpy(reinterpret_cast<void *>(getBuckets()), other.getBuckets(), |
| 432 | getNumBuckets() * sizeof(BucketT)); |
| 433 | else |
| 434 | for (size_t i = 0; i < getNumBuckets(); ++i) { |
| 435 | ::new (&getBuckets()[i].getFirst()) |
| 436 | KeyT(other.getBuckets()[i].getFirst()); |
| 437 | if (!KeyInfoT::isEqual(getBuckets()[i].getFirst(), getEmptyKey()) && |
| 438 | !KeyInfoT::isEqual(getBuckets()[i].getFirst(), getTombstoneKey())) |
| 439 | ::new (&getBuckets()[i].getSecond()) |
| 440 | ValueT(other.getBuckets()[i].getSecond()); |
| 441 | } |
| 442 | } |
| 443 | |
| 444 | static unsigned getHashValue(const KeyT &Val) { |
| 445 | return KeyInfoT::getHashValue(Val); |
| 446 | } |
| 447 | |
| 448 | template<typename LookupKeyT> |
| 449 | static unsigned getHashValue(const LookupKeyT &Val) { |
| 450 | return KeyInfoT::getHashValue(Val); |
| 451 | } |
| 452 | |
| 453 | static const KeyT getEmptyKey() { |
| 454 | static_assert(std::is_base_of<DenseMapBase, DerivedT>::value, |
| 455 | "Must pass the derived type to this template!"); |
| 456 | return KeyInfoT::getEmptyKey(); |
| 457 | } |
| 458 | |
| 459 | static const KeyT getTombstoneKey() { |
| 460 | return KeyInfoT::getTombstoneKey(); |
| 461 | } |
| 462 | |
| 463 | private: |
| 464 | iterator makeIterator(BucketT *P, BucketT *E, |
| 465 | DebugEpochBase &Epoch, |
| 466 | bool NoAdvance=false) { |
| 467 | if (shouldReverseIterate<KeyT>()) { |
| 468 | BucketT *B = P == getBucketsEnd() ? getBuckets() : P + 1; |
| 469 | return iterator(B, E, Epoch, NoAdvance); |
| 470 | } |
| 471 | return iterator(P, E, Epoch, NoAdvance); |
| 472 | } |
| 473 | |
| 474 | const_iterator makeConstIterator(const BucketT *P, const BucketT *E, |
| 475 | const DebugEpochBase &Epoch, |
| 476 | const bool NoAdvance=false) const { |
| 477 | if (shouldReverseIterate<KeyT>()) { |
| 478 | const BucketT *B = P == getBucketsEnd() ? getBuckets() : P + 1; |
| 479 | return const_iterator(B, E, Epoch, NoAdvance); |
| 480 | } |
| 481 | return const_iterator(P, E, Epoch, NoAdvance); |
| 482 | } |
| 483 | |
| 484 | unsigned getNumEntries() const { |
| 485 | return static_cast<const DerivedT *>(this)->getNumEntries(); |
| 486 | } |
| 487 | |
| 488 | void setNumEntries(unsigned Num) { |
| 489 | static_cast<DerivedT *>(this)->setNumEntries(Num); |
| 490 | } |
| 491 | |
| 492 | void incrementNumEntries() { |
| 493 | setNumEntries(getNumEntries() + 1); |
| 494 | } |
| 495 | |
| 496 | void decrementNumEntries() { |
| 497 | setNumEntries(getNumEntries() - 1); |
| 498 | } |
| 499 | |
| 500 | unsigned getNumTombstones() const { |
| 501 | return static_cast<const DerivedT *>(this)->getNumTombstones(); |
| 502 | } |
| 503 | |
| 504 | void setNumTombstones(unsigned Num) { |
| 505 | static_cast<DerivedT *>(this)->setNumTombstones(Num); |
| 506 | } |
| 507 | |
| 508 | void incrementNumTombstones() { |
| 509 | setNumTombstones(getNumTombstones() + 1); |
| 510 | } |
| 511 | |
| 512 | void decrementNumTombstones() { |
| 513 | setNumTombstones(getNumTombstones() - 1); |
| 514 | } |
| 515 | |
| 516 | const BucketT *getBuckets() const { |
| 517 | return static_cast<const DerivedT *>(this)->getBuckets(); |
| 518 | } |
| 519 | |
| 520 | BucketT *getBuckets() { |
| 521 | return static_cast<DerivedT *>(this)->getBuckets(); |
| 522 | } |
| 523 | |
| 524 | unsigned getNumBuckets() const { |
| 525 | return static_cast<const DerivedT *>(this)->getNumBuckets(); |
| 526 | } |
| 527 | |
| 528 | BucketT *getBucketsEnd() { |
| 529 | return getBuckets() + getNumBuckets(); |
| 530 | } |
| 531 | |
| 532 | const BucketT *getBucketsEnd() const { |
| 533 | return getBuckets() + getNumBuckets(); |
| 534 | } |
| 535 | |
| 536 | void grow(unsigned AtLeast) { |
| 537 | static_cast<DerivedT *>(this)->grow(AtLeast); |
| 538 | } |
| 539 | |
| 540 | void shrink_and_clear() { |
| 541 | static_cast<DerivedT *>(this)->shrink_and_clear(); |
| 542 | } |
| 543 | |
| 544 | template <typename KeyArg, typename... ValueArgs> |
| 545 | BucketT *InsertIntoBucket(BucketT *TheBucket, KeyArg &&Key, |
| 546 | ValueArgs &&... Values) { |
| 547 | TheBucket = InsertIntoBucketImpl(Key, Key, TheBucket); |
| 548 | |
| 549 | TheBucket->getFirst() = std::forward<KeyArg>(Key); |
| 550 | ::new (&TheBucket->getSecond()) ValueT(std::forward<ValueArgs>(Values)...); |
| 551 | return TheBucket; |
| 552 | } |
| 553 | |
| 554 | template <typename LookupKeyT> |
| 555 | BucketT *InsertIntoBucketWithLookup(BucketT *TheBucket, KeyT &&Key, |
| 556 | ValueT &&Value, LookupKeyT &Lookup) { |
| 557 | TheBucket = InsertIntoBucketImpl(Key, Lookup, TheBucket); |
| 558 | |
| 559 | TheBucket->getFirst() = std::move(Key); |
| 560 | ::new (&TheBucket->getSecond()) ValueT(std::move(Value)); |
| 561 | return TheBucket; |
| 562 | } |
| 563 | |
| 564 | template <typename LookupKeyT> |
| 565 | BucketT *InsertIntoBucketImpl(const KeyT &Key, const LookupKeyT &Lookup, |
| 566 | BucketT *TheBucket) { |
| 567 | incrementEpoch(); |
| 568 | |
| 569 | // If the load of the hash table is more than 3/4, or if fewer than 1/8 of |
| 570 | // the buckets are empty (meaning that many are filled with tombstones), |
| 571 | // grow the table. |
| 572 | // |
| 573 | // The later case is tricky. For example, if we had one empty bucket with |
| 574 | // tons of tombstones, failing lookups (e.g. for insertion) would have to |
| 575 | // probe almost the entire table until it found the empty bucket. If the |
| 576 | // table completely filled with tombstones, no lookup would ever succeed, |
| 577 | // causing infinite loops in lookup. |
| 578 | unsigned NewNumEntries = getNumEntries() + 1; |
| 579 | unsigned NumBuckets = getNumBuckets(); |
| 580 | if (LLVM_UNLIKELY(NewNumEntries * 4 >= NumBuckets * 3)__builtin_expect((bool)(NewNumEntries * 4 >= NumBuckets * 3 ), false)) { |
| 581 | this->grow(NumBuckets * 2); |
| 582 | LookupBucketFor(Lookup, TheBucket); |
| 583 | NumBuckets = getNumBuckets(); |
| 584 | } else if (LLVM_UNLIKELY(NumBuckets-(NewNumEntries+getNumTombstones()) <=__builtin_expect((bool)(NumBuckets-(NewNumEntries+getNumTombstones ()) <= NumBuckets/8), false) |
| 585 | NumBuckets/8)__builtin_expect((bool)(NumBuckets-(NewNumEntries+getNumTombstones ()) <= NumBuckets/8), false)) { |
| 586 | this->grow(NumBuckets); |
| 587 | LookupBucketFor(Lookup, TheBucket); |
| 588 | } |
| 589 | assert(TheBucket)((void)0); |
| 590 | |
| 591 | // Only update the state after we've grown our bucket space appropriately |
| 592 | // so that when growing buckets we have self-consistent entry count. |
| 593 | incrementNumEntries(); |
| 594 | |
| 595 | // If we are writing over a tombstone, remember this. |
| 596 | const KeyT EmptyKey = getEmptyKey(); |
| 597 | if (!KeyInfoT::isEqual(TheBucket->getFirst(), EmptyKey)) |
| 598 | decrementNumTombstones(); |
| 599 | |
| 600 | return TheBucket; |
| 601 | } |
| 602 | |
| 603 | /// LookupBucketFor - Lookup the appropriate bucket for Val, returning it in |
| 604 | /// FoundBucket. If the bucket contains the key and a value, this returns |
| 605 | /// true, otherwise it returns a bucket with an empty marker or tombstone and |
| 606 | /// returns false. |
| 607 | template<typename LookupKeyT> |
| 608 | bool LookupBucketFor(const LookupKeyT &Val, |
| 609 | const BucketT *&FoundBucket) const { |
| 610 | const BucketT *BucketsPtr = getBuckets(); |
| 611 | const unsigned NumBuckets = getNumBuckets(); |
| 612 | |
| 613 | if (NumBuckets == 0) { |
| 614 | FoundBucket = nullptr; |
| 615 | return false; |
| 616 | } |
| 617 | |
| 618 | // FoundTombstone - Keep track of whether we find a tombstone while probing. |
| 619 | const BucketT *FoundTombstone = nullptr; |
| 620 | const KeyT EmptyKey = getEmptyKey(); |
| 621 | const KeyT TombstoneKey = getTombstoneKey(); |
| 622 | assert(!KeyInfoT::isEqual(Val, EmptyKey) &&((void)0) |
| 623 | !KeyInfoT::isEqual(Val, TombstoneKey) &&((void)0) |
| 624 | "Empty/Tombstone value shouldn't be inserted into map!")((void)0); |
| 625 | |
| 626 | unsigned BucketNo = getHashValue(Val) & (NumBuckets-1); |
| 627 | unsigned ProbeAmt = 1; |
| 628 | while (true) { |
| 629 | const BucketT *ThisBucket = BucketsPtr + BucketNo; |
| 630 | // Found Val's bucket? If so, return it. |
| 631 | if (LLVM_LIKELY(KeyInfoT::isEqual(Val, ThisBucket->getFirst()))__builtin_expect((bool)(KeyInfoT::isEqual(Val, ThisBucket-> getFirst())), true)) { |
| 632 | FoundBucket = ThisBucket; |
| 633 | return true; |
| 634 | } |
| 635 | |
| 636 | // If we found an empty bucket, the key doesn't exist in the set. |
| 637 | // Insert it and return the default value. |
| 638 | if (LLVM_LIKELY(KeyInfoT::isEqual(ThisBucket->getFirst(), EmptyKey))__builtin_expect((bool)(KeyInfoT::isEqual(ThisBucket->getFirst (), EmptyKey)), true)) { |
| 639 | // If we've already seen a tombstone while probing, fill it in instead |
| 640 | // of the empty bucket we eventually probed to. |
| 641 | FoundBucket = FoundTombstone ? FoundTombstone : ThisBucket; |
| 642 | return false; |
| 643 | } |
| 644 | |
| 645 | // If this is a tombstone, remember it. If Val ends up not in the map, we |
| 646 | // prefer to return it than something that would require more probing. |
| 647 | if (KeyInfoT::isEqual(ThisBucket->getFirst(), TombstoneKey) && |
| 648 | !FoundTombstone) |
| 649 | FoundTombstone = ThisBucket; // Remember the first tombstone found. |
| 650 | |
| 651 | // Otherwise, it's a hash collision or a tombstone, continue quadratic |
| 652 | // probing. |
| 653 | BucketNo += ProbeAmt++; |
| 654 | BucketNo &= (NumBuckets-1); |
| 655 | } |
| 656 | } |
| 657 | |
| 658 | template <typename LookupKeyT> |
| 659 | bool LookupBucketFor(const LookupKeyT &Val, BucketT *&FoundBucket) { |
| 660 | const BucketT *ConstFoundBucket; |
| 661 | bool Result = const_cast<const DenseMapBase *>(this) |
| 662 | ->LookupBucketFor(Val, ConstFoundBucket); |
| 663 | FoundBucket = const_cast<BucketT *>(ConstFoundBucket); |
| 664 | return Result; |
| 665 | } |
| 666 | |
| 667 | public: |
| 668 | /// Return the approximate size (in bytes) of the actual map. |
| 669 | /// This is just the raw memory used by DenseMap. |
| 670 | /// If entries are pointers to objects, the size of the referenced objects |
| 671 | /// are not included. |
| 672 | size_t getMemorySize() const { |
| 673 | return getNumBuckets() * sizeof(BucketT); |
| 674 | } |
| 675 | }; |
| 676 | |
| 677 | /// Equality comparison for DenseMap. |
| 678 | /// |
| 679 | /// Iterates over elements of LHS confirming that each (key, value) pair in LHS |
| 680 | /// is also in RHS, and that no additional pairs are in RHS. |
| 681 | /// Equivalent to N calls to RHS.find and N value comparisons. Amortized |
| 682 | /// complexity is linear, worst case is O(N^2) (if every hash collides). |
| 683 | template <typename DerivedT, typename KeyT, typename ValueT, typename KeyInfoT, |
| 684 | typename BucketT> |
| 685 | bool operator==( |
| 686 | const DenseMapBase<DerivedT, KeyT, ValueT, KeyInfoT, BucketT> &LHS, |
| 687 | const DenseMapBase<DerivedT, KeyT, ValueT, KeyInfoT, BucketT> &RHS) { |
| 688 | if (LHS.size() != RHS.size()) |
| 689 | return false; |
| 690 | |
| 691 | for (auto &KV : LHS) { |
| 692 | auto I = RHS.find(KV.first); |
| 693 | if (I == RHS.end() || I->second != KV.second) |
| 694 | return false; |
| 695 | } |
| 696 | |
| 697 | return true; |
| 698 | } |
| 699 | |
| 700 | /// Inequality comparison for DenseMap. |
| 701 | /// |
| 702 | /// Equivalent to !(LHS == RHS). See operator== for performance notes. |
| 703 | template <typename DerivedT, typename KeyT, typename ValueT, typename KeyInfoT, |
| 704 | typename BucketT> |
| 705 | bool operator!=( |
| 706 | const DenseMapBase<DerivedT, KeyT, ValueT, KeyInfoT, BucketT> &LHS, |
| 707 | const DenseMapBase<DerivedT, KeyT, ValueT, KeyInfoT, BucketT> &RHS) { |
| 708 | return !(LHS == RHS); |
| 709 | } |
| 710 | |
| 711 | template <typename KeyT, typename ValueT, |
| 712 | typename KeyInfoT = DenseMapInfo<KeyT>, |
| 713 | typename BucketT = llvm::detail::DenseMapPair<KeyT, ValueT>> |
| 714 | class DenseMap : public DenseMapBase<DenseMap<KeyT, ValueT, KeyInfoT, BucketT>, |
| 715 | KeyT, ValueT, KeyInfoT, BucketT> { |
| 716 | friend class DenseMapBase<DenseMap, KeyT, ValueT, KeyInfoT, BucketT>; |
| 717 | |
| 718 | // Lift some types from the dependent base class into this class for |
| 719 | // simplicity of referring to them. |
| 720 | using BaseT = DenseMapBase<DenseMap, KeyT, ValueT, KeyInfoT, BucketT>; |
| 721 | |
| 722 | BucketT *Buckets; |
| 723 | unsigned NumEntries; |
| 724 | unsigned NumTombstones; |
| 725 | unsigned NumBuckets; |
| 726 | |
| 727 | public: |
| 728 | /// Create a DenseMap with an optional \p InitialReserve that guarantee that |
| 729 | /// this number of elements can be inserted in the map without grow() |
| 730 | explicit DenseMap(unsigned InitialReserve = 0) { init(InitialReserve); } |
| 731 | |
| 732 | DenseMap(const DenseMap &other) : BaseT() { |
| 733 | init(0); |
| 734 | copyFrom(other); |
| 735 | } |
| 736 | |
| 737 | DenseMap(DenseMap &&other) : BaseT() { |
| 738 | init(0); |
| 739 | swap(other); |
| 740 | } |
| 741 | |
| 742 | template<typename InputIt> |
| 743 | DenseMap(const InputIt &I, const InputIt &E) { |
| 744 | init(std::distance(I, E)); |
| 745 | this->insert(I, E); |
| 746 | } |
| 747 | |
| 748 | DenseMap(std::initializer_list<typename BaseT::value_type> Vals) { |
| 749 | init(Vals.size()); |
| 750 | this->insert(Vals.begin(), Vals.end()); |
| 751 | } |
| 752 | |
| 753 | ~DenseMap() { |
| 754 | this->destroyAll(); |
| 755 | deallocate_buffer(Buckets, sizeof(BucketT) * NumBuckets, alignof(BucketT)); |
| 756 | } |
| 757 | |
| 758 | void swap(DenseMap& RHS) { |
| 759 | this->incrementEpoch(); |
| 760 | RHS.incrementEpoch(); |
| 761 | std::swap(Buckets, RHS.Buckets); |
| 762 | std::swap(NumEntries, RHS.NumEntries); |
| 763 | std::swap(NumTombstones, RHS.NumTombstones); |
| 764 | std::swap(NumBuckets, RHS.NumBuckets); |
| 765 | } |
| 766 | |
| 767 | DenseMap& operator=(const DenseMap& other) { |
| 768 | if (&other != this) |
| 769 | copyFrom(other); |
| 770 | return *this; |
| 771 | } |
| 772 | |
| 773 | DenseMap& operator=(DenseMap &&other) { |
| 774 | this->destroyAll(); |
| 775 | deallocate_buffer(Buckets, sizeof(BucketT) * NumBuckets, alignof(BucketT)); |
| 776 | init(0); |
| 777 | swap(other); |
| 778 | return *this; |
| 779 | } |
| 780 | |
| 781 | void copyFrom(const DenseMap& other) { |
| 782 | this->destroyAll(); |
| 783 | deallocate_buffer(Buckets, sizeof(BucketT) * NumBuckets, alignof(BucketT)); |
| 784 | if (allocateBuckets(other.NumBuckets)) { |
| 785 | this->BaseT::copyFrom(other); |
| 786 | } else { |
| 787 | NumEntries = 0; |
| 788 | NumTombstones = 0; |
| 789 | } |
| 790 | } |
| 791 | |
| 792 | void init(unsigned InitNumEntries) { |
| 793 | auto InitBuckets = BaseT::getMinBucketToReserveForEntries(InitNumEntries); |
| 794 | if (allocateBuckets(InitBuckets)) { |
| 795 | this->BaseT::initEmpty(); |
| 796 | } else { |
| 797 | NumEntries = 0; |
| 798 | NumTombstones = 0; |
| 799 | } |
| 800 | } |
| 801 | |
| 802 | void grow(unsigned AtLeast) { |
| 803 | unsigned OldNumBuckets = NumBuckets; |
| 804 | BucketT *OldBuckets = Buckets; |
| 805 | |
| 806 | allocateBuckets(std::max<unsigned>(64, static_cast<unsigned>(NextPowerOf2(AtLeast-1)))); |
| 807 | assert(Buckets)((void)0); |
| 808 | if (!OldBuckets) { |
| 809 | this->BaseT::initEmpty(); |
| 810 | return; |
| 811 | } |
| 812 | |
| 813 | this->moveFromOldBuckets(OldBuckets, OldBuckets+OldNumBuckets); |
| 814 | |
| 815 | // Free the old table. |
| 816 | deallocate_buffer(OldBuckets, sizeof(BucketT) * OldNumBuckets, |
| 817 | alignof(BucketT)); |
| 818 | } |
| 819 | |
| 820 | void shrink_and_clear() { |
| 821 | unsigned OldNumBuckets = NumBuckets; |
| 822 | unsigned OldNumEntries = NumEntries; |
| 823 | this->destroyAll(); |
| 824 | |
| 825 | // Reduce the number of buckets. |
| 826 | unsigned NewNumBuckets = 0; |
| 827 | if (OldNumEntries) |
| 828 | NewNumBuckets = std::max(64, 1 << (Log2_32_Ceil(OldNumEntries) + 1)); |
| 829 | if (NewNumBuckets == NumBuckets) { |
| 830 | this->BaseT::initEmpty(); |
| 831 | return; |
| 832 | } |
| 833 | |
| 834 | deallocate_buffer(Buckets, sizeof(BucketT) * OldNumBuckets, |
| 835 | alignof(BucketT)); |
| 836 | init(NewNumBuckets); |
| 837 | } |
| 838 | |
| 839 | private: |
| 840 | unsigned getNumEntries() const { |
| 841 | return NumEntries; |
| 842 | } |
| 843 | |
| 844 | void setNumEntries(unsigned Num) { |
| 845 | NumEntries = Num; |
| 846 | } |
| 847 | |
| 848 | unsigned getNumTombstones() const { |
| 849 | return NumTombstones; |
| 850 | } |
| 851 | |
| 852 | void setNumTombstones(unsigned Num) { |
| 853 | NumTombstones = Num; |
| 854 | } |
| 855 | |
| 856 | BucketT *getBuckets() const { |
| 857 | return Buckets; |
| 858 | } |
| 859 | |
| 860 | unsigned getNumBuckets() const { |
| 861 | return NumBuckets; |
| 862 | } |
| 863 | |
| 864 | bool allocateBuckets(unsigned Num) { |
| 865 | NumBuckets = Num; |
| 866 | if (NumBuckets == 0) { |
| 867 | Buckets = nullptr; |
| 868 | return false; |
| 869 | } |
| 870 | |
| 871 | Buckets = static_cast<BucketT *>( |
| 872 | allocate_buffer(sizeof(BucketT) * NumBuckets, alignof(BucketT))); |
| 873 | return true; |
| 874 | } |
| 875 | }; |
| 876 | |
| 877 | template <typename KeyT, typename ValueT, unsigned InlineBuckets = 4, |
| 878 | typename KeyInfoT = DenseMapInfo<KeyT>, |
| 879 | typename BucketT = llvm::detail::DenseMapPair<KeyT, ValueT>> |
| 880 | class SmallDenseMap |
| 881 | : public DenseMapBase< |
| 882 | SmallDenseMap<KeyT, ValueT, InlineBuckets, KeyInfoT, BucketT>, KeyT, |
| 883 | ValueT, KeyInfoT, BucketT> { |
| 884 | friend class DenseMapBase<SmallDenseMap, KeyT, ValueT, KeyInfoT, BucketT>; |
| 885 | |
| 886 | // Lift some types from the dependent base class into this class for |
| 887 | // simplicity of referring to them. |
| 888 | using BaseT = DenseMapBase<SmallDenseMap, KeyT, ValueT, KeyInfoT, BucketT>; |
| 889 | |
| 890 | static_assert(isPowerOf2_64(InlineBuckets), |
| 891 | "InlineBuckets must be a power of 2."); |
| 892 | |
| 893 | unsigned Small : 1; |
| 894 | unsigned NumEntries : 31; |
| 895 | unsigned NumTombstones; |
| 896 | |
| 897 | struct LargeRep { |
| 898 | BucketT *Buckets; |
| 899 | unsigned NumBuckets; |
| 900 | }; |
| 901 | |
| 902 | /// A "union" of an inline bucket array and the struct representing |
| 903 | /// a large bucket. This union will be discriminated by the 'Small' bit. |
| 904 | AlignedCharArrayUnion<BucketT[InlineBuckets], LargeRep> storage; |
| 905 | |
| 906 | public: |
| 907 | explicit SmallDenseMap(unsigned NumInitBuckets = 0) { |
| 908 | init(NumInitBuckets); |
| 909 | } |
| 910 | |
| 911 | SmallDenseMap(const SmallDenseMap &other) : BaseT() { |
| 912 | init(0); |
| 913 | copyFrom(other); |
| 914 | } |
| 915 | |
| 916 | SmallDenseMap(SmallDenseMap &&other) : BaseT() { |
| 917 | init(0); |
| 918 | swap(other); |
| 919 | } |
| 920 | |
| 921 | template<typename InputIt> |
| 922 | SmallDenseMap(const InputIt &I, const InputIt &E) { |
| 923 | init(NextPowerOf2(std::distance(I, E))); |
| 924 | this->insert(I, E); |
| 925 | } |
| 926 | |
| 927 | SmallDenseMap(std::initializer_list<typename BaseT::value_type> Vals) |
| 928 | : SmallDenseMap(Vals.begin(), Vals.end()) {} |
| 929 | |
| 930 | ~SmallDenseMap() { |
| 931 | this->destroyAll(); |
| 932 | deallocateBuckets(); |
| 933 | } |
| 934 | |
| 935 | void swap(SmallDenseMap& RHS) { |
| 936 | unsigned TmpNumEntries = RHS.NumEntries; |
| 937 | RHS.NumEntries = NumEntries; |
| 938 | NumEntries = TmpNumEntries; |
| 939 | std::swap(NumTombstones, RHS.NumTombstones); |
| 940 | |
| 941 | const KeyT EmptyKey = this->getEmptyKey(); |
| 942 | const KeyT TombstoneKey = this->getTombstoneKey(); |
| 943 | if (Small && RHS.Small) { |
| 944 | // If we're swapping inline bucket arrays, we have to cope with some of |
| 945 | // the tricky bits of DenseMap's storage system: the buckets are not |
| 946 | // fully initialized. Thus we swap every key, but we may have |
| 947 | // a one-directional move of the value. |
| 948 | for (unsigned i = 0, e = InlineBuckets; i != e; ++i) { |
| 949 | BucketT *LHSB = &getInlineBuckets()[i], |
| 950 | *RHSB = &RHS.getInlineBuckets()[i]; |
| 951 | bool hasLHSValue = (!KeyInfoT::isEqual(LHSB->getFirst(), EmptyKey) && |
| 952 | !KeyInfoT::isEqual(LHSB->getFirst(), TombstoneKey)); |
| 953 | bool hasRHSValue = (!KeyInfoT::isEqual(RHSB->getFirst(), EmptyKey) && |
| 954 | !KeyInfoT::isEqual(RHSB->getFirst(), TombstoneKey)); |
| 955 | if (hasLHSValue && hasRHSValue) { |
| 956 | // Swap together if we can... |
| 957 | std::swap(*LHSB, *RHSB); |
| 958 | continue; |
| 959 | } |
| 960 | // Swap separately and handle any asymmetry. |
| 961 | std::swap(LHSB->getFirst(), RHSB->getFirst()); |
| 962 | if (hasLHSValue) { |
| 963 | ::new (&RHSB->getSecond()) ValueT(std::move(LHSB->getSecond())); |
| 964 | LHSB->getSecond().~ValueT(); |
| 965 | } else if (hasRHSValue) { |
| 966 | ::new (&LHSB->getSecond()) ValueT(std::move(RHSB->getSecond())); |
| 967 | RHSB->getSecond().~ValueT(); |
| 968 | } |
| 969 | } |
| 970 | return; |
| 971 | } |
| 972 | if (!Small && !RHS.Small) { |
| 973 | std::swap(getLargeRep()->Buckets, RHS.getLargeRep()->Buckets); |
| 974 | std::swap(getLargeRep()->NumBuckets, RHS.getLargeRep()->NumBuckets); |
| 975 | return; |
| 976 | } |
| 977 | |
| 978 | SmallDenseMap &SmallSide = Small ? *this : RHS; |
| 979 | SmallDenseMap &LargeSide = Small ? RHS : *this; |
| 980 | |
| 981 | // First stash the large side's rep and move the small side across. |
| 982 | LargeRep TmpRep = std::move(*LargeSide.getLargeRep()); |
| 983 | LargeSide.getLargeRep()->~LargeRep(); |
| 984 | LargeSide.Small = true; |
| 985 | // This is similar to the standard move-from-old-buckets, but the bucket |
| 986 | // count hasn't actually rotated in this case. So we have to carefully |
| 987 | // move construct the keys and values into their new locations, but there |
| 988 | // is no need to re-hash things. |
| 989 | for (unsigned i = 0, e = InlineBuckets; i != e; ++i) { |
| 990 | BucketT *NewB = &LargeSide.getInlineBuckets()[i], |
| 991 | *OldB = &SmallSide.getInlineBuckets()[i]; |
| 992 | ::new (&NewB->getFirst()) KeyT(std::move(OldB->getFirst())); |
| 993 | OldB->getFirst().~KeyT(); |
| 994 | if (!KeyInfoT::isEqual(NewB->getFirst(), EmptyKey) && |
| 995 | !KeyInfoT::isEqual(NewB->getFirst(), TombstoneKey)) { |
| 996 | ::new (&NewB->getSecond()) ValueT(std::move(OldB->getSecond())); |
| 997 | OldB->getSecond().~ValueT(); |
| 998 | } |
| 999 | } |
| 1000 | |
| 1001 | // The hard part of moving the small buckets across is done, just move |
| 1002 | // the TmpRep into its new home. |
| 1003 | SmallSide.Small = false; |
| 1004 | new (SmallSide.getLargeRep()) LargeRep(std::move(TmpRep)); |
| 1005 | } |
| 1006 | |
| 1007 | SmallDenseMap& operator=(const SmallDenseMap& other) { |
| 1008 | if (&other != this) |
| 1009 | copyFrom(other); |
| 1010 | return *this; |
| 1011 | } |
| 1012 | |
| 1013 | SmallDenseMap& operator=(SmallDenseMap &&other) { |
| 1014 | this->destroyAll(); |
| 1015 | deallocateBuckets(); |
| 1016 | init(0); |
| 1017 | swap(other); |
| 1018 | return *this; |
| 1019 | } |
| 1020 | |
| 1021 | void copyFrom(const SmallDenseMap& other) { |
| 1022 | this->destroyAll(); |
| 1023 | deallocateBuckets(); |
| 1024 | Small = true; |
| 1025 | if (other.getNumBuckets() > InlineBuckets) { |
| 1026 | Small = false; |
| 1027 | new (getLargeRep()) LargeRep(allocateBuckets(other.getNumBuckets())); |
| 1028 | } |
| 1029 | this->BaseT::copyFrom(other); |
| 1030 | } |
| 1031 | |
| 1032 | void init(unsigned InitBuckets) { |
| 1033 | Small = true; |
| 1034 | if (InitBuckets > InlineBuckets) { |
| 1035 | Small = false; |
| 1036 | new (getLargeRep()) LargeRep(allocateBuckets(InitBuckets)); |
| 1037 | } |
| 1038 | this->BaseT::initEmpty(); |
| 1039 | } |
| 1040 | |
| 1041 | void grow(unsigned AtLeast) { |
| 1042 | if (AtLeast > InlineBuckets) |
| 1043 | AtLeast = std::max<unsigned>(64, NextPowerOf2(AtLeast-1)); |
| 1044 | |
| 1045 | if (Small) { |
| 1046 | // First move the inline buckets into a temporary storage. |
| 1047 | AlignedCharArrayUnion<BucketT[InlineBuckets]> TmpStorage; |
| 1048 | BucketT *TmpBegin = reinterpret_cast<BucketT *>(&TmpStorage); |
| 1049 | BucketT *TmpEnd = TmpBegin; |
| 1050 | |
| 1051 | // Loop over the buckets, moving non-empty, non-tombstones into the |
| 1052 | // temporary storage. Have the loop move the TmpEnd forward as it goes. |
| 1053 | const KeyT EmptyKey = this->getEmptyKey(); |
| 1054 | const KeyT TombstoneKey = this->getTombstoneKey(); |
| 1055 | for (BucketT *P = getBuckets(), *E = P + InlineBuckets; P != E; ++P) { |
| 1056 | if (!KeyInfoT::isEqual(P->getFirst(), EmptyKey) && |
| 1057 | !KeyInfoT::isEqual(P->getFirst(), TombstoneKey)) { |
| 1058 | assert(size_t(TmpEnd - TmpBegin) < InlineBuckets &&((void)0) |
| 1059 | "Too many inline buckets!")((void)0); |
| 1060 | ::new (&TmpEnd->getFirst()) KeyT(std::move(P->getFirst())); |
| 1061 | ::new (&TmpEnd->getSecond()) ValueT(std::move(P->getSecond())); |
| 1062 | ++TmpEnd; |
| 1063 | P->getSecond().~ValueT(); |
| 1064 | } |
| 1065 | P->getFirst().~KeyT(); |
| 1066 | } |
| 1067 | |
| 1068 | // AtLeast == InlineBuckets can happen if there are many tombstones, |
| 1069 | // and grow() is used to remove them. Usually we always switch to the |
| 1070 | // large rep here. |
| 1071 | if (AtLeast > InlineBuckets) { |
| 1072 | Small = false; |
| 1073 | new (getLargeRep()) LargeRep(allocateBuckets(AtLeast)); |
| 1074 | } |
| 1075 | this->moveFromOldBuckets(TmpBegin, TmpEnd); |
| 1076 | return; |
| 1077 | } |
| 1078 | |
| 1079 | LargeRep OldRep = std::move(*getLargeRep()); |
| 1080 | getLargeRep()->~LargeRep(); |
| 1081 | if (AtLeast <= InlineBuckets) { |
| 1082 | Small = true; |
| 1083 | } else { |
| 1084 | new (getLargeRep()) LargeRep(allocateBuckets(AtLeast)); |
| 1085 | } |
| 1086 | |
| 1087 | this->moveFromOldBuckets(OldRep.Buckets, OldRep.Buckets+OldRep.NumBuckets); |
| 1088 | |
| 1089 | // Free the old table. |
| 1090 | deallocate_buffer(OldRep.Buckets, sizeof(BucketT) * OldRep.NumBuckets, |
| 1091 | alignof(BucketT)); |
| 1092 | } |
| 1093 | |
| 1094 | void shrink_and_clear() { |
| 1095 | unsigned OldSize = this->size(); |
| 1096 | this->destroyAll(); |
| 1097 | |
| 1098 | // Reduce the number of buckets. |
| 1099 | unsigned NewNumBuckets = 0; |
| 1100 | if (OldSize) { |
| 1101 | NewNumBuckets = 1 << (Log2_32_Ceil(OldSize) + 1); |
| 1102 | if (NewNumBuckets > InlineBuckets && NewNumBuckets < 64u) |
| 1103 | NewNumBuckets = 64; |
| 1104 | } |
| 1105 | if ((Small && NewNumBuckets <= InlineBuckets) || |
| 1106 | (!Small && NewNumBuckets == getLargeRep()->NumBuckets)) { |
| 1107 | this->BaseT::initEmpty(); |
| 1108 | return; |
| 1109 | } |
| 1110 | |
| 1111 | deallocateBuckets(); |
| 1112 | init(NewNumBuckets); |
| 1113 | } |
| 1114 | |
| 1115 | private: |
| 1116 | unsigned getNumEntries() const { |
| 1117 | return NumEntries; |
| 1118 | } |
| 1119 | |
| 1120 | void setNumEntries(unsigned Num) { |
| 1121 | // NumEntries is hardcoded to be 31 bits wide. |
| 1122 | assert(Num < (1U << 31) && "Cannot support more than 1<<31 entries")((void)0); |
| 1123 | NumEntries = Num; |
| 1124 | } |
| 1125 | |
| 1126 | unsigned getNumTombstones() const { |
| 1127 | return NumTombstones; |
| 1128 | } |
| 1129 | |
| 1130 | void setNumTombstones(unsigned Num) { |
| 1131 | NumTombstones = Num; |
| 1132 | } |
| 1133 | |
| 1134 | const BucketT *getInlineBuckets() const { |
| 1135 | assert(Small)((void)0); |
| 1136 | // Note that this cast does not violate aliasing rules as we assert that |
| 1137 | // the memory's dynamic type is the small, inline bucket buffer, and the |
| 1138 | // 'storage' is a POD containing a char buffer. |
| 1139 | return reinterpret_cast<const BucketT *>(&storage); |
| 1140 | } |
| 1141 | |
| 1142 | BucketT *getInlineBuckets() { |
| 1143 | return const_cast<BucketT *>( |
| 1144 | const_cast<const SmallDenseMap *>(this)->getInlineBuckets()); |
| 1145 | } |
| 1146 | |
| 1147 | const LargeRep *getLargeRep() const { |
| 1148 | assert(!Small)((void)0); |
| 1149 | // Note, same rule about aliasing as with getInlineBuckets. |
| 1150 | return reinterpret_cast<const LargeRep *>(&storage); |
| 1151 | } |
| 1152 | |
| 1153 | LargeRep *getLargeRep() { |
| 1154 | return const_cast<LargeRep *>( |
| 1155 | const_cast<const SmallDenseMap *>(this)->getLargeRep()); |
| 1156 | } |
| 1157 | |
| 1158 | const BucketT *getBuckets() const { |
| 1159 | return Small ? getInlineBuckets() : getLargeRep()->Buckets; |
| 1160 | } |
| 1161 | |
| 1162 | BucketT *getBuckets() { |
| 1163 | return const_cast<BucketT *>( |
| 1164 | const_cast<const SmallDenseMap *>(this)->getBuckets()); |
| 1165 | } |
| 1166 | |
| 1167 | unsigned getNumBuckets() const { |
| 1168 | return Small ? InlineBuckets : getLargeRep()->NumBuckets; |
| 1169 | } |
| 1170 | |
| 1171 | void deallocateBuckets() { |
| 1172 | if (Small) |
| 1173 | return; |
| 1174 | |
| 1175 | deallocate_buffer(getLargeRep()->Buckets, |
| 1176 | sizeof(BucketT) * getLargeRep()->NumBuckets, |
| 1177 | alignof(BucketT)); |
| 1178 | getLargeRep()->~LargeRep(); |
| 1179 | } |
| 1180 | |
| 1181 | LargeRep allocateBuckets(unsigned Num) { |
| 1182 | assert(Num > InlineBuckets && "Must allocate more buckets than are inline")((void)0); |
| 1183 | LargeRep Rep = {static_cast<BucketT *>(allocate_buffer( |
| 1184 | sizeof(BucketT) * Num, alignof(BucketT))), |
| 1185 | Num}; |
| 1186 | return Rep; |
| 1187 | } |
| 1188 | }; |
| 1189 | |
| 1190 | template <typename KeyT, typename ValueT, typename KeyInfoT, typename Bucket, |
| 1191 | bool IsConst> |
| 1192 | class DenseMapIterator : DebugEpochBase::HandleBase { |
| 1193 | friend class DenseMapIterator<KeyT, ValueT, KeyInfoT, Bucket, true>; |
| 1194 | friend class DenseMapIterator<KeyT, ValueT, KeyInfoT, Bucket, false>; |
| 1195 | |
| 1196 | public: |
| 1197 | using difference_type = ptrdiff_t; |
| 1198 | using value_type = |
| 1199 | typename std::conditional<IsConst, const Bucket, Bucket>::type; |
| 1200 | using pointer = value_type *; |
| 1201 | using reference = value_type &; |
| 1202 | using iterator_category = std::forward_iterator_tag; |
| 1203 | |
| 1204 | private: |
| 1205 | pointer Ptr = nullptr; |
| 1206 | pointer End = nullptr; |
| 1207 | |
| 1208 | public: |
| 1209 | DenseMapIterator() = default; |
| 1210 | |
| 1211 | DenseMapIterator(pointer Pos, pointer E, const DebugEpochBase &Epoch, |
| 1212 | bool NoAdvance = false) |
| 1213 | : DebugEpochBase::HandleBase(&Epoch), Ptr(Pos), End(E) { |
| 1214 | assert(isHandleInSync() && "invalid construction!")((void)0); |
| 1215 | |
| 1216 | if (NoAdvance) return; |
| 1217 | if (shouldReverseIterate<KeyT>()) { |
| 1218 | RetreatPastEmptyBuckets(); |
| 1219 | return; |
| 1220 | } |
| 1221 | AdvancePastEmptyBuckets(); |
| 1222 | } |
| 1223 | |
| 1224 | // Converting ctor from non-const iterators to const iterators. SFINAE'd out |
| 1225 | // for const iterator destinations so it doesn't end up as a user defined copy |
| 1226 | // constructor. |
| 1227 | template <bool IsConstSrc, |
| 1228 | typename = std::enable_if_t<!IsConstSrc && IsConst>> |
| 1229 | DenseMapIterator( |
| 1230 | const DenseMapIterator<KeyT, ValueT, KeyInfoT, Bucket, IsConstSrc> &I) |
| 1231 | : DebugEpochBase::HandleBase(I), Ptr(I.Ptr), End(I.End) {} |
| 1232 | |
| 1233 | reference operator*() const { |
| 1234 | assert(isHandleInSync() && "invalid iterator access!")((void)0); |
| 1235 | assert(Ptr != End && "dereferencing end() iterator")((void)0); |
| 1236 | if (shouldReverseIterate<KeyT>()) |
| 1237 | return Ptr[-1]; |
| 1238 | return *Ptr; |
| 1239 | } |
| 1240 | pointer operator->() const { |
| 1241 | assert(isHandleInSync() && "invalid iterator access!")((void)0); |
| 1242 | assert(Ptr != End && "dereferencing end() iterator")((void)0); |
| 1243 | if (shouldReverseIterate<KeyT>()) |
| 1244 | return &(Ptr[-1]); |
| 1245 | return Ptr; |
| 1246 | } |
| 1247 | |
| 1248 | friend bool operator==(const DenseMapIterator &LHS, |
| 1249 | const DenseMapIterator &RHS) { |
| 1250 | assert((!LHS.Ptr || LHS.isHandleInSync()) && "handle not in sync!")((void)0); |
| 1251 | assert((!RHS.Ptr || RHS.isHandleInSync()) && "handle not in sync!")((void)0); |
| 1252 | assert(LHS.getEpochAddress() == RHS.getEpochAddress() &&((void)0) |
| 1253 | "comparing incomparable iterators!")((void)0); |
| 1254 | return LHS.Ptr == RHS.Ptr; |
| 1255 | } |
| 1256 | |
| 1257 | friend bool operator!=(const DenseMapIterator &LHS, |
| 1258 | const DenseMapIterator &RHS) { |
| 1259 | return !(LHS == RHS); |
| 1260 | } |
| 1261 | |
| 1262 | inline DenseMapIterator& operator++() { // Preincrement |
| 1263 | assert(isHandleInSync() && "invalid iterator access!")((void)0); |
| 1264 | assert(Ptr != End && "incrementing end() iterator")((void)0); |
| 1265 | if (shouldReverseIterate<KeyT>()) { |
| 1266 | --Ptr; |
| 1267 | RetreatPastEmptyBuckets(); |
| 1268 | return *this; |
| 1269 | } |
| 1270 | ++Ptr; |
| 1271 | AdvancePastEmptyBuckets(); |
| 1272 | return *this; |
| 1273 | } |
| 1274 | DenseMapIterator operator++(int) { // Postincrement |
| 1275 | assert(isHandleInSync() && "invalid iterator access!")((void)0); |
| 1276 | DenseMapIterator tmp = *this; ++*this; return tmp; |
| 1277 | } |
| 1278 | |
| 1279 | private: |
| 1280 | void AdvancePastEmptyBuckets() { |
| 1281 | assert(Ptr <= End)((void)0); |
| 1282 | const KeyT Empty = KeyInfoT::getEmptyKey(); |
| 1283 | const KeyT Tombstone = KeyInfoT::getTombstoneKey(); |
| 1284 | |
| 1285 | while (Ptr != End && (KeyInfoT::isEqual(Ptr->getFirst(), Empty) || |
| 1286 | KeyInfoT::isEqual(Ptr->getFirst(), Tombstone))) |
| 1287 | ++Ptr; |
| 1288 | } |
| 1289 | |
| 1290 | void RetreatPastEmptyBuckets() { |
| 1291 | assert(Ptr >= End)((void)0); |
| 1292 | const KeyT Empty = KeyInfoT::getEmptyKey(); |
| 1293 | const KeyT Tombstone = KeyInfoT::getTombstoneKey(); |
| 1294 | |
| 1295 | while (Ptr != End && (KeyInfoT::isEqual(Ptr[-1].getFirst(), Empty) || |
| 1296 | KeyInfoT::isEqual(Ptr[-1].getFirst(), Tombstone))) |
| 1297 | --Ptr; |
| 1298 | } |
| 1299 | }; |
| 1300 | |
| 1301 | template <typename KeyT, typename ValueT, typename KeyInfoT> |
| 1302 | inline size_t capacity_in_bytes(const DenseMap<KeyT, ValueT, KeyInfoT> &X) { |
| 1303 | return X.getMemorySize(); |
| 1304 | } |
| 1305 | |
| 1306 | } // end namespace llvm |
| 1307 | |
| 1308 | #endif // LLVM_ADT_DENSEMAP_H |