HexagonCommonGEP.cpp revision 321369
1286425Sdim//===--- HexagonCommonGEP.cpp ---------------------------------------------===// 2286425Sdim// 3286425Sdim// The LLVM Compiler Infrastructure 4286425Sdim// 5286425Sdim// This file is distributed under the University of Illinois Open Source 6286425Sdim// License. See LICENSE.TXT for details. 7286425Sdim// 8286425Sdim//===----------------------------------------------------------------------===// 9286425Sdim 10286425Sdim#define DEBUG_TYPE "commgep" 11286425Sdim 12314564Sdim#include "llvm/ADT/ArrayRef.h" 13286425Sdim#include "llvm/ADT/FoldingSet.h" 14286425Sdim#include "llvm/ADT/STLExtras.h" 15314564Sdim#include "llvm/ADT/StringRef.h" 16286425Sdim#include "llvm/Analysis/LoopInfo.h" 17286425Sdim#include "llvm/Analysis/PostDominators.h" 18314564Sdim#include "llvm/IR/BasicBlock.h" 19314564Sdim#include "llvm/IR/Constant.h" 20286425Sdim#include "llvm/IR/Constants.h" 21314564Sdim#include "llvm/IR/DerivedTypes.h" 22286425Sdim#include "llvm/IR/Dominators.h" 23286425Sdim#include "llvm/IR/Function.h" 24314564Sdim#include "llvm/IR/Instruction.h" 25286425Sdim#include "llvm/IR/Instructions.h" 26314564Sdim#include "llvm/IR/Type.h" 27314564Sdim#include "llvm/IR/Use.h" 28314564Sdim#include "llvm/IR/User.h" 29314564Sdim#include "llvm/IR/Value.h" 30286425Sdim#include "llvm/IR/Verifier.h" 31314564Sdim#include "llvm/Pass.h" 32286425Sdim#include "llvm/Support/Allocator.h" 33314564Sdim#include "llvm/Support/Casting.h" 34286425Sdim#include "llvm/Support/CommandLine.h" 35314564Sdim#include "llvm/Support/Compiler.h" 36286425Sdim#include "llvm/Support/Debug.h" 37286425Sdim#include "llvm/Support/raw_ostream.h" 38286425Sdim#include "llvm/Transforms/Utils/Local.h" 39314564Sdim#include <algorithm> 40314564Sdim#include <cassert> 41314564Sdim#include <cstddef> 42314564Sdim#include <cstdint> 43314564Sdim#include <iterator> 44286425Sdim#include <map> 45286425Sdim#include <set> 46314564Sdim#include <utility> 47286425Sdim#include <vector> 48286425Sdim 49286425Sdimusing namespace llvm; 50286425Sdim 51286425Sdimstatic cl::opt<bool> OptSpeculate("commgep-speculate", cl::init(true), 52286425Sdim cl::Hidden, cl::ZeroOrMore); 53286425Sdim 54286425Sdimstatic cl::opt<bool> OptEnableInv("commgep-inv", cl::init(true), cl::Hidden, 55286425Sdim cl::ZeroOrMore); 56286425Sdim 57286425Sdimstatic cl::opt<bool> OptEnableConst("commgep-const", cl::init(true), 58286425Sdim cl::Hidden, cl::ZeroOrMore); 59286425Sdim 60286425Sdimnamespace llvm { 61314564Sdim 62286425Sdim void initializeHexagonCommonGEPPass(PassRegistry&); 63286425Sdim 64314564Sdim} // end namespace llvm 65314564Sdim 66286425Sdimnamespace { 67314564Sdim 68286425Sdim struct GepNode; 69286425Sdim typedef std::set<GepNode*> NodeSet; 70286425Sdim typedef std::map<GepNode*,Value*> NodeToValueMap; 71286425Sdim typedef std::vector<GepNode*> NodeVect; 72286425Sdim typedef std::map<GepNode*,NodeVect> NodeChildrenMap; 73286425Sdim typedef std::set<Use*> UseSet; 74286425Sdim typedef std::map<GepNode*,UseSet> NodeToUsesMap; 75286425Sdim 76286425Sdim // Numbering map for gep nodes. Used to keep track of ordering for 77286425Sdim // gep nodes. 78296417Sdim struct NodeOrdering { 79314564Sdim NodeOrdering() = default; 80286425Sdim 81296417Sdim void insert(const GepNode *N) { Map.insert(std::make_pair(N, ++LastNum)); } 82296417Sdim void clear() { Map.clear(); } 83296417Sdim 84296417Sdim bool operator()(const GepNode *N1, const GepNode *N2) const { 85296417Sdim auto F1 = Map.find(N1), F2 = Map.find(N2); 86296417Sdim assert(F1 != Map.end() && F2 != Map.end()); 87286425Sdim return F1->second < F2->second; 88286425Sdim } 89296417Sdim 90286425Sdim private: 91296417Sdim std::map<const GepNode *, unsigned> Map; 92314564Sdim unsigned LastNum = 0; 93286425Sdim }; 94286425Sdim 95286425Sdim class HexagonCommonGEP : public FunctionPass { 96286425Sdim public: 97286425Sdim static char ID; 98314564Sdim 99286425Sdim HexagonCommonGEP() : FunctionPass(ID) { 100286425Sdim initializeHexagonCommonGEPPass(*PassRegistry::getPassRegistry()); 101286425Sdim } 102286425Sdim 103314564Sdim bool runOnFunction(Function &F) override; 104314564Sdim StringRef getPassName() const override { return "Hexagon Common GEP"; } 105314564Sdim 106314564Sdim void getAnalysisUsage(AnalysisUsage &AU) const override { 107286425Sdim AU.addRequired<DominatorTreeWrapperPass>(); 108286425Sdim AU.addPreserved<DominatorTreeWrapperPass>(); 109309124Sdim AU.addRequired<PostDominatorTreeWrapperPass>(); 110309124Sdim AU.addPreserved<PostDominatorTreeWrapperPass>(); 111286425Sdim AU.addRequired<LoopInfoWrapperPass>(); 112286425Sdim AU.addPreserved<LoopInfoWrapperPass>(); 113286425Sdim FunctionPass::getAnalysisUsage(AU); 114286425Sdim } 115286425Sdim 116286425Sdim private: 117286425Sdim typedef std::map<Value*,GepNode*> ValueToNodeMap; 118286425Sdim typedef std::vector<Value*> ValueVect; 119286425Sdim typedef std::map<GepNode*,ValueVect> NodeToValuesMap; 120286425Sdim 121286425Sdim void getBlockTraversalOrder(BasicBlock *Root, ValueVect &Order); 122286425Sdim bool isHandledGepForm(GetElementPtrInst *GepI); 123286425Sdim void processGepInst(GetElementPtrInst *GepI, ValueToNodeMap &NM); 124286425Sdim void collect(); 125286425Sdim void common(); 126286425Sdim 127286425Sdim BasicBlock *recalculatePlacement(GepNode *Node, NodeChildrenMap &NCM, 128286425Sdim NodeToValueMap &Loc); 129286425Sdim BasicBlock *recalculatePlacementRec(GepNode *Node, NodeChildrenMap &NCM, 130286425Sdim NodeToValueMap &Loc); 131286425Sdim bool isInvariantIn(Value *Val, Loop *L); 132286425Sdim bool isInvariantIn(GepNode *Node, Loop *L); 133286425Sdim bool isInMainPath(BasicBlock *B, Loop *L); 134286425Sdim BasicBlock *adjustForInvariance(GepNode *Node, NodeChildrenMap &NCM, 135286425Sdim NodeToValueMap &Loc); 136286425Sdim void separateChainForNode(GepNode *Node, Use *U, NodeToValueMap &Loc); 137286425Sdim void separateConstantChains(GepNode *Node, NodeChildrenMap &NCM, 138286425Sdim NodeToValueMap &Loc); 139286425Sdim void computeNodePlacement(NodeToValueMap &Loc); 140286425Sdim 141286425Sdim Value *fabricateGEP(NodeVect &NA, BasicBlock::iterator At, 142286425Sdim BasicBlock *LocB); 143286425Sdim void getAllUsersForNode(GepNode *Node, ValueVect &Values, 144286425Sdim NodeChildrenMap &NCM); 145286425Sdim void materialize(NodeToValueMap &Loc); 146286425Sdim 147286425Sdim void removeDeadCode(); 148286425Sdim 149286425Sdim NodeVect Nodes; 150286425Sdim NodeToUsesMap Uses; 151286425Sdim NodeOrdering NodeOrder; // Node ordering, for deterministic behavior. 152286425Sdim SpecificBumpPtrAllocator<GepNode> *Mem; 153286425Sdim LLVMContext *Ctx; 154286425Sdim LoopInfo *LI; 155286425Sdim DominatorTree *DT; 156286425Sdim PostDominatorTree *PDT; 157286425Sdim Function *Fn; 158286425Sdim }; 159286425Sdim 160314564Sdim} // end anonymous namespace 161286425Sdim 162286425Sdimchar HexagonCommonGEP::ID = 0; 163286425SdimINITIALIZE_PASS_BEGIN(HexagonCommonGEP, "hcommgep", "Hexagon Common GEP", 164286425Sdim false, false) 165286425SdimINITIALIZE_PASS_DEPENDENCY(DominatorTreeWrapperPass) 166309124SdimINITIALIZE_PASS_DEPENDENCY(PostDominatorTreeWrapperPass) 167286425SdimINITIALIZE_PASS_DEPENDENCY(LoopInfoWrapperPass) 168286425SdimINITIALIZE_PASS_END(HexagonCommonGEP, "hcommgep", "Hexagon Common GEP", 169286425Sdim false, false) 170286425Sdim 171286425Sdimnamespace { 172314564Sdim 173286425Sdim struct GepNode { 174286425Sdim enum { 175286425Sdim None = 0, 176286425Sdim Root = 0x01, 177286425Sdim Internal = 0x02, 178321369Sdim Used = 0x04, 179321369Sdim InBounds = 0x08 180286425Sdim }; 181286425Sdim 182286425Sdim uint32_t Flags; 183286425Sdim union { 184286425Sdim GepNode *Parent; 185286425Sdim Value *BaseVal; 186286425Sdim }; 187286425Sdim Value *Idx; 188286425Sdim Type *PTy; // Type of the pointer operand. 189286425Sdim 190314564Sdim GepNode() : Flags(0), Parent(nullptr), Idx(nullptr), PTy(nullptr) {} 191286425Sdim GepNode(const GepNode *N) : Flags(N->Flags), Idx(N->Idx), PTy(N->PTy) { 192286425Sdim if (Flags & Root) 193286425Sdim BaseVal = N->BaseVal; 194286425Sdim else 195286425Sdim Parent = N->Parent; 196286425Sdim } 197314564Sdim 198286425Sdim friend raw_ostream &operator<< (raw_ostream &OS, const GepNode &GN); 199286425Sdim }; 200286425Sdim 201286425Sdim Type *next_type(Type *Ty, Value *Idx) { 202314564Sdim if (auto *PTy = dyn_cast<PointerType>(Ty)) 203314564Sdim return PTy->getElementType(); 204286425Sdim // Advance the type. 205286425Sdim if (!Ty->isStructTy()) { 206286425Sdim Type *NexTy = cast<SequentialType>(Ty)->getElementType(); 207286425Sdim return NexTy; 208286425Sdim } 209286425Sdim // Otherwise it is a struct type. 210286425Sdim ConstantInt *CI = dyn_cast<ConstantInt>(Idx); 211286425Sdim assert(CI && "Struct type with non-constant index"); 212286425Sdim int64_t i = CI->getValue().getSExtValue(); 213286425Sdim Type *NextTy = cast<StructType>(Ty)->getElementType(i); 214286425Sdim return NextTy; 215286425Sdim } 216286425Sdim 217286425Sdim raw_ostream &operator<< (raw_ostream &OS, const GepNode &GN) { 218286425Sdim OS << "{ {"; 219286425Sdim bool Comma = false; 220286425Sdim if (GN.Flags & GepNode::Root) { 221286425Sdim OS << "root"; 222286425Sdim Comma = true; 223286425Sdim } 224286425Sdim if (GN.Flags & GepNode::Internal) { 225286425Sdim if (Comma) 226286425Sdim OS << ','; 227286425Sdim OS << "internal"; 228286425Sdim Comma = true; 229286425Sdim } 230286425Sdim if (GN.Flags & GepNode::Used) { 231286425Sdim if (Comma) 232286425Sdim OS << ','; 233286425Sdim OS << "used"; 234286425Sdim } 235321369Sdim if (GN.Flags & GepNode::InBounds) { 236321369Sdim if (Comma) 237321369Sdim OS << ','; 238321369Sdim OS << "inbounds"; 239321369Sdim } 240286425Sdim OS << "} "; 241286425Sdim if (GN.Flags & GepNode::Root) 242286425Sdim OS << "BaseVal:" << GN.BaseVal->getName() << '(' << GN.BaseVal << ')'; 243286425Sdim else 244286425Sdim OS << "Parent:" << GN.Parent; 245286425Sdim 246286425Sdim OS << " Idx:"; 247286425Sdim if (ConstantInt *CI = dyn_cast<ConstantInt>(GN.Idx)) 248286425Sdim OS << CI->getValue().getSExtValue(); 249286425Sdim else if (GN.Idx->hasName()) 250286425Sdim OS << GN.Idx->getName(); 251286425Sdim else 252286425Sdim OS << "<anon> =" << *GN.Idx; 253286425Sdim 254286425Sdim OS << " PTy:"; 255286425Sdim if (GN.PTy->isStructTy()) { 256286425Sdim StructType *STy = cast<StructType>(GN.PTy); 257286425Sdim if (!STy->isLiteral()) 258286425Sdim OS << GN.PTy->getStructName(); 259286425Sdim else 260286425Sdim OS << "<anon-struct>:" << *STy; 261286425Sdim } 262286425Sdim else 263286425Sdim OS << *GN.PTy; 264286425Sdim OS << " }"; 265286425Sdim return OS; 266286425Sdim } 267286425Sdim 268286425Sdim template <typename NodeContainer> 269286425Sdim void dump_node_container(raw_ostream &OS, const NodeContainer &S) { 270286425Sdim typedef typename NodeContainer::const_iterator const_iterator; 271286425Sdim for (const_iterator I = S.begin(), E = S.end(); I != E; ++I) 272286425Sdim OS << *I << ' ' << **I << '\n'; 273286425Sdim } 274286425Sdim 275286425Sdim raw_ostream &operator<< (raw_ostream &OS, 276286425Sdim const NodeVect &S) LLVM_ATTRIBUTE_UNUSED; 277286425Sdim raw_ostream &operator<< (raw_ostream &OS, const NodeVect &S) { 278286425Sdim dump_node_container(OS, S); 279286425Sdim return OS; 280286425Sdim } 281286425Sdim 282286425Sdim raw_ostream &operator<< (raw_ostream &OS, 283286425Sdim const NodeToUsesMap &M) LLVM_ATTRIBUTE_UNUSED; 284286425Sdim raw_ostream &operator<< (raw_ostream &OS, const NodeToUsesMap &M){ 285286425Sdim typedef NodeToUsesMap::const_iterator const_iterator; 286286425Sdim for (const_iterator I = M.begin(), E = M.end(); I != E; ++I) { 287286425Sdim const UseSet &Us = I->second; 288286425Sdim OS << I->first << " -> #" << Us.size() << '{'; 289286425Sdim for (UseSet::const_iterator J = Us.begin(), F = Us.end(); J != F; ++J) { 290286425Sdim User *R = (*J)->getUser(); 291286425Sdim if (R->hasName()) 292286425Sdim OS << ' ' << R->getName(); 293286425Sdim else 294286425Sdim OS << " <?>(" << *R << ')'; 295286425Sdim } 296286425Sdim OS << " }\n"; 297286425Sdim } 298286425Sdim return OS; 299286425Sdim } 300286425Sdim 301286425Sdim struct in_set { 302286425Sdim in_set(const NodeSet &S) : NS(S) {} 303286425Sdim bool operator() (GepNode *N) const { 304286425Sdim return NS.find(N) != NS.end(); 305286425Sdim } 306314564Sdim 307286425Sdim private: 308286425Sdim const NodeSet &NS; 309286425Sdim }; 310286425Sdim 311314564Sdim} // end anonymous namespace 312286425Sdim 313286425Sdiminline void *operator new(size_t, SpecificBumpPtrAllocator<GepNode> &A) { 314286425Sdim return A.Allocate(); 315286425Sdim} 316286425Sdim 317286425Sdimvoid HexagonCommonGEP::getBlockTraversalOrder(BasicBlock *Root, 318286425Sdim ValueVect &Order) { 319286425Sdim // Compute block ordering for a typical DT-based traversal of the flow 320286425Sdim // graph: "before visiting a block, all of its dominators must have been 321286425Sdim // visited". 322286425Sdim 323286425Sdim Order.push_back(Root); 324321369Sdim for (auto *DTN : children<DomTreeNode*>(DT->getNode(Root))) 325321369Sdim getBlockTraversalOrder(DTN->getBlock(), Order); 326286425Sdim} 327286425Sdim 328286425Sdimbool HexagonCommonGEP::isHandledGepForm(GetElementPtrInst *GepI) { 329286425Sdim // No vector GEPs. 330286425Sdim if (!GepI->getType()->isPointerTy()) 331286425Sdim return false; 332286425Sdim // No GEPs without any indices. (Is this possible?) 333286425Sdim if (GepI->idx_begin() == GepI->idx_end()) 334286425Sdim return false; 335286425Sdim return true; 336286425Sdim} 337286425Sdim 338286425Sdimvoid HexagonCommonGEP::processGepInst(GetElementPtrInst *GepI, 339286425Sdim ValueToNodeMap &NM) { 340286425Sdim DEBUG(dbgs() << "Visiting GEP: " << *GepI << '\n'); 341286425Sdim GepNode *N = new (*Mem) GepNode; 342286425Sdim Value *PtrOp = GepI->getPointerOperand(); 343321369Sdim uint32_t InBounds = GepI->isInBounds() ? GepNode::InBounds : 0; 344286425Sdim ValueToNodeMap::iterator F = NM.find(PtrOp); 345286425Sdim if (F == NM.end()) { 346286425Sdim N->BaseVal = PtrOp; 347321369Sdim N->Flags |= GepNode::Root | InBounds; 348286425Sdim } else { 349286425Sdim // If PtrOp was a GEP instruction, it must have already been processed. 350286425Sdim // The ValueToNodeMap entry for it is the last gep node in the generated 351286425Sdim // chain. Link to it here. 352286425Sdim N->Parent = F->second; 353286425Sdim } 354286425Sdim N->PTy = PtrOp->getType(); 355286425Sdim N->Idx = *GepI->idx_begin(); 356286425Sdim 357286425Sdim // Collect the list of users of this GEP instruction. Will add it to the 358286425Sdim // last node created for it. 359286425Sdim UseSet Us; 360286425Sdim for (Value::user_iterator UI = GepI->user_begin(), UE = GepI->user_end(); 361286425Sdim UI != UE; ++UI) { 362286425Sdim // Check if this gep is used by anything other than other geps that 363286425Sdim // we will process. 364286425Sdim if (isa<GetElementPtrInst>(*UI)) { 365286425Sdim GetElementPtrInst *UserG = cast<GetElementPtrInst>(*UI); 366286425Sdim if (isHandledGepForm(UserG)) 367286425Sdim continue; 368286425Sdim } 369286425Sdim Us.insert(&UI.getUse()); 370286425Sdim } 371286425Sdim Nodes.push_back(N); 372286425Sdim NodeOrder.insert(N); 373286425Sdim 374286425Sdim // Skip the first index operand, since we only handle 0. This dereferences 375286425Sdim // the pointer operand. 376286425Sdim GepNode *PN = N; 377286425Sdim Type *PtrTy = cast<PointerType>(PtrOp->getType())->getElementType(); 378286425Sdim for (User::op_iterator OI = GepI->idx_begin()+1, OE = GepI->idx_end(); 379286425Sdim OI != OE; ++OI) { 380286425Sdim Value *Op = *OI; 381286425Sdim GepNode *Nx = new (*Mem) GepNode; 382286425Sdim Nx->Parent = PN; // Link Nx to the previous node. 383321369Sdim Nx->Flags |= GepNode::Internal | InBounds; 384286425Sdim Nx->PTy = PtrTy; 385286425Sdim Nx->Idx = Op; 386286425Sdim Nodes.push_back(Nx); 387286425Sdim NodeOrder.insert(Nx); 388286425Sdim PN = Nx; 389286425Sdim 390286425Sdim PtrTy = next_type(PtrTy, Op); 391286425Sdim } 392286425Sdim 393286425Sdim // After last node has been created, update the use information. 394286425Sdim if (!Us.empty()) { 395286425Sdim PN->Flags |= GepNode::Used; 396286425Sdim Uses[PN].insert(Us.begin(), Us.end()); 397286425Sdim } 398286425Sdim 399286425Sdim // Link the last node with the originating GEP instruction. This is to 400286425Sdim // help with linking chained GEP instructions. 401286425Sdim NM.insert(std::make_pair(GepI, PN)); 402286425Sdim} 403286425Sdim 404286425Sdimvoid HexagonCommonGEP::collect() { 405286425Sdim // Establish depth-first traversal order of the dominator tree. 406286425Sdim ValueVect BO; 407296417Sdim getBlockTraversalOrder(&Fn->front(), BO); 408286425Sdim 409286425Sdim // The creation of gep nodes requires DT-traversal. When processing a GEP 410286425Sdim // instruction that uses another GEP instruction as the base pointer, the 411286425Sdim // gep node for the base pointer should already exist. 412286425Sdim ValueToNodeMap NM; 413286425Sdim for (ValueVect::iterator I = BO.begin(), E = BO.end(); I != E; ++I) { 414286425Sdim BasicBlock *B = cast<BasicBlock>(*I); 415286425Sdim for (BasicBlock::iterator J = B->begin(), F = B->end(); J != F; ++J) { 416286425Sdim if (!isa<GetElementPtrInst>(J)) 417286425Sdim continue; 418286425Sdim GetElementPtrInst *GepI = cast<GetElementPtrInst>(J); 419286425Sdim if (isHandledGepForm(GepI)) 420286425Sdim processGepInst(GepI, NM); 421286425Sdim } 422286425Sdim } 423286425Sdim 424286425Sdim DEBUG(dbgs() << "Gep nodes after initial collection:\n" << Nodes); 425286425Sdim} 426286425Sdim 427314564Sdimstatic void invert_find_roots(const NodeVect &Nodes, NodeChildrenMap &NCM, 428314564Sdim NodeVect &Roots) { 429286425Sdim typedef NodeVect::const_iterator const_iterator; 430286425Sdim for (const_iterator I = Nodes.begin(), E = Nodes.end(); I != E; ++I) { 431286425Sdim GepNode *N = *I; 432286425Sdim if (N->Flags & GepNode::Root) { 433286425Sdim Roots.push_back(N); 434286425Sdim continue; 435286425Sdim } 436286425Sdim GepNode *PN = N->Parent; 437286425Sdim NCM[PN].push_back(N); 438286425Sdim } 439314564Sdim} 440286425Sdim 441314564Sdimstatic void nodes_for_root(GepNode *Root, NodeChildrenMap &NCM, 442314564Sdim NodeSet &Nodes) { 443286425Sdim NodeVect Work; 444286425Sdim Work.push_back(Root); 445286425Sdim Nodes.insert(Root); 446286425Sdim 447286425Sdim while (!Work.empty()) { 448286425Sdim NodeVect::iterator First = Work.begin(); 449286425Sdim GepNode *N = *First; 450286425Sdim Work.erase(First); 451286425Sdim NodeChildrenMap::iterator CF = NCM.find(N); 452286425Sdim if (CF != NCM.end()) { 453286425Sdim Work.insert(Work.end(), CF->second.begin(), CF->second.end()); 454286425Sdim Nodes.insert(CF->second.begin(), CF->second.end()); 455286425Sdim } 456286425Sdim } 457286425Sdim} 458286425Sdim 459314564Sdimnamespace { 460286425Sdim 461286425Sdim typedef std::set<NodeSet> NodeSymRel; 462286425Sdim typedef std::pair<GepNode*,GepNode*> NodePair; 463286425Sdim typedef std::set<NodePair> NodePairSet; 464286425Sdim 465314564Sdim} // end anonymous namespace 466314564Sdim 467314564Sdimstatic const NodeSet *node_class(GepNode *N, NodeSymRel &Rel) { 468286425Sdim for (NodeSymRel::iterator I = Rel.begin(), E = Rel.end(); I != E; ++I) 469286425Sdim if (I->count(N)) 470286425Sdim return &*I; 471314564Sdim return nullptr; 472314564Sdim} 473286425Sdim 474286425Sdim // Create an ordered pair of GepNode pointers. The pair will be used in 475286425Sdim // determining equality. The only purpose of the ordering is to eliminate 476286425Sdim // duplication due to the commutativity of equality/non-equality. 477314564Sdimstatic NodePair node_pair(GepNode *N1, GepNode *N2) { 478286425Sdim uintptr_t P1 = uintptr_t(N1), P2 = uintptr_t(N2); 479286425Sdim if (P1 <= P2) 480286425Sdim return std::make_pair(N1, N2); 481286425Sdim return std::make_pair(N2, N1); 482314564Sdim} 483286425Sdim 484314564Sdimstatic unsigned node_hash(GepNode *N) { 485286425Sdim // Include everything except flags and parent. 486286425Sdim FoldingSetNodeID ID; 487286425Sdim ID.AddPointer(N->Idx); 488286425Sdim ID.AddPointer(N->PTy); 489286425Sdim return ID.ComputeHash(); 490314564Sdim} 491286425Sdim 492314564Sdimstatic bool node_eq(GepNode *N1, GepNode *N2, NodePairSet &Eq, 493314564Sdim NodePairSet &Ne) { 494286425Sdim // Don't cache the result for nodes with different hashes. The hash 495286425Sdim // comparison is fast enough. 496286425Sdim if (node_hash(N1) != node_hash(N2)) 497286425Sdim return false; 498286425Sdim 499286425Sdim NodePair NP = node_pair(N1, N2); 500286425Sdim NodePairSet::iterator FEq = Eq.find(NP); 501286425Sdim if (FEq != Eq.end()) 502286425Sdim return true; 503286425Sdim NodePairSet::iterator FNe = Ne.find(NP); 504286425Sdim if (FNe != Ne.end()) 505286425Sdim return false; 506286425Sdim // Not previously compared. 507286425Sdim bool Root1 = N1->Flags & GepNode::Root; 508286425Sdim bool Root2 = N2->Flags & GepNode::Root; 509286425Sdim NodePair P = node_pair(N1, N2); 510286425Sdim // If the Root flag has different values, the nodes are different. 511286425Sdim // If both nodes are root nodes, but their base pointers differ, 512286425Sdim // they are different. 513286425Sdim if (Root1 != Root2 || (Root1 && N1->BaseVal != N2->BaseVal)) { 514286425Sdim Ne.insert(P); 515286425Sdim return false; 516286425Sdim } 517286425Sdim // Here the root flags are identical, and for root nodes the 518286425Sdim // base pointers are equal, so the root nodes are equal. 519286425Sdim // For non-root nodes, compare their parent nodes. 520286425Sdim if (Root1 || node_eq(N1->Parent, N2->Parent, Eq, Ne)) { 521286425Sdim Eq.insert(P); 522286425Sdim return true; 523286425Sdim } 524286425Sdim return false; 525286425Sdim} 526286425Sdim 527286425Sdimvoid HexagonCommonGEP::common() { 528286425Sdim // The essence of this commoning is finding gep nodes that are equal. 529286425Sdim // To do this we need to compare all pairs of nodes. To save time, 530286425Sdim // first, partition the set of all nodes into sets of potentially equal 531286425Sdim // nodes, and then compare pairs from within each partition. 532286425Sdim typedef std::map<unsigned,NodeSet> NodeSetMap; 533286425Sdim NodeSetMap MaybeEq; 534286425Sdim 535286425Sdim for (NodeVect::iterator I = Nodes.begin(), E = Nodes.end(); I != E; ++I) { 536286425Sdim GepNode *N = *I; 537286425Sdim unsigned H = node_hash(N); 538286425Sdim MaybeEq[H].insert(N); 539286425Sdim } 540286425Sdim 541286425Sdim // Compute the equivalence relation for the gep nodes. Use two caches, 542286425Sdim // one for equality and the other for non-equality. 543286425Sdim NodeSymRel EqRel; // Equality relation (as set of equivalence classes). 544286425Sdim NodePairSet Eq, Ne; // Caches. 545286425Sdim for (NodeSetMap::iterator I = MaybeEq.begin(), E = MaybeEq.end(); 546286425Sdim I != E; ++I) { 547286425Sdim NodeSet &S = I->second; 548286425Sdim for (NodeSet::iterator NI = S.begin(), NE = S.end(); NI != NE; ++NI) { 549286425Sdim GepNode *N = *NI; 550286425Sdim // If node already has a class, then the class must have been created 551286425Sdim // in a prior iteration of this loop. Since equality is transitive, 552286425Sdim // nothing more will be added to that class, so skip it. 553286425Sdim if (node_class(N, EqRel)) 554286425Sdim continue; 555286425Sdim 556286425Sdim // Create a new class candidate now. 557286425Sdim NodeSet C; 558286425Sdim for (NodeSet::iterator NJ = std::next(NI); NJ != NE; ++NJ) 559286425Sdim if (node_eq(N, *NJ, Eq, Ne)) 560286425Sdim C.insert(*NJ); 561286425Sdim // If Tmp is empty, N would be the only element in it. Don't bother 562286425Sdim // creating a class for it then. 563286425Sdim if (!C.empty()) { 564286425Sdim C.insert(N); // Finalize the set before adding it to the relation. 565286425Sdim std::pair<NodeSymRel::iterator, bool> Ins = EqRel.insert(C); 566286425Sdim (void)Ins; 567286425Sdim assert(Ins.second && "Cannot add a class"); 568286425Sdim } 569286425Sdim } 570286425Sdim } 571286425Sdim 572286425Sdim DEBUG({ 573286425Sdim dbgs() << "Gep node equality:\n"; 574286425Sdim for (NodePairSet::iterator I = Eq.begin(), E = Eq.end(); I != E; ++I) 575286425Sdim dbgs() << "{ " << I->first << ", " << I->second << " }\n"; 576286425Sdim 577286425Sdim dbgs() << "Gep equivalence classes:\n"; 578286425Sdim for (NodeSymRel::iterator I = EqRel.begin(), E = EqRel.end(); I != E; ++I) { 579286425Sdim dbgs() << '{'; 580286425Sdim const NodeSet &S = *I; 581286425Sdim for (NodeSet::const_iterator J = S.begin(), F = S.end(); J != F; ++J) { 582286425Sdim if (J != S.begin()) 583286425Sdim dbgs() << ','; 584286425Sdim dbgs() << ' ' << *J; 585286425Sdim } 586286425Sdim dbgs() << " }\n"; 587286425Sdim } 588286425Sdim }); 589286425Sdim 590286425Sdim // Create a projection from a NodeSet to the minimal element in it. 591286425Sdim typedef std::map<const NodeSet*,GepNode*> ProjMap; 592286425Sdim ProjMap PM; 593286425Sdim for (NodeSymRel::iterator I = EqRel.begin(), E = EqRel.end(); I != E; ++I) { 594286425Sdim const NodeSet &S = *I; 595286425Sdim GepNode *Min = *std::min_element(S.begin(), S.end(), NodeOrder); 596286425Sdim std::pair<ProjMap::iterator,bool> Ins = PM.insert(std::make_pair(&S, Min)); 597286425Sdim (void)Ins; 598286425Sdim assert(Ins.second && "Cannot add minimal element"); 599286425Sdim 600286425Sdim // Update the min element's flags, and user list. 601286425Sdim uint32_t Flags = 0; 602286425Sdim UseSet &MinUs = Uses[Min]; 603286425Sdim for (NodeSet::iterator J = S.begin(), F = S.end(); J != F; ++J) { 604286425Sdim GepNode *N = *J; 605286425Sdim uint32_t NF = N->Flags; 606286425Sdim // If N is used, append all original values of N to the list of 607286425Sdim // original values of Min. 608286425Sdim if (NF & GepNode::Used) 609286425Sdim MinUs.insert(Uses[N].begin(), Uses[N].end()); 610286425Sdim Flags |= NF; 611286425Sdim } 612286425Sdim if (MinUs.empty()) 613286425Sdim Uses.erase(Min); 614286425Sdim 615286425Sdim // The collected flags should include all the flags from the min element. 616286425Sdim assert((Min->Flags & Flags) == Min->Flags); 617286425Sdim Min->Flags = Flags; 618286425Sdim } 619286425Sdim 620286425Sdim // Commoning: for each non-root gep node, replace "Parent" with the 621286425Sdim // selected (minimum) node from the corresponding equivalence class. 622286425Sdim // If a given parent does not have an equivalence class, leave it 623286425Sdim // unchanged (it means that it's the only element in its class). 624286425Sdim for (NodeVect::iterator I = Nodes.begin(), E = Nodes.end(); I != E; ++I) { 625286425Sdim GepNode *N = *I; 626286425Sdim if (N->Flags & GepNode::Root) 627286425Sdim continue; 628286425Sdim const NodeSet *PC = node_class(N->Parent, EqRel); 629286425Sdim if (!PC) 630286425Sdim continue; 631286425Sdim ProjMap::iterator F = PM.find(PC); 632286425Sdim if (F == PM.end()) 633286425Sdim continue; 634286425Sdim // Found a replacement, use it. 635286425Sdim GepNode *Rep = F->second; 636286425Sdim N->Parent = Rep; 637286425Sdim } 638286425Sdim 639286425Sdim DEBUG(dbgs() << "Gep nodes after commoning:\n" << Nodes); 640286425Sdim 641286425Sdim // Finally, erase the nodes that are no longer used. 642286425Sdim NodeSet Erase; 643286425Sdim for (NodeVect::iterator I = Nodes.begin(), E = Nodes.end(); I != E; ++I) { 644286425Sdim GepNode *N = *I; 645286425Sdim const NodeSet *PC = node_class(N, EqRel); 646286425Sdim if (!PC) 647286425Sdim continue; 648286425Sdim ProjMap::iterator F = PM.find(PC); 649286425Sdim if (F == PM.end()) 650286425Sdim continue; 651286425Sdim if (N == F->second) 652286425Sdim continue; 653286425Sdim // Node for removal. 654286425Sdim Erase.insert(*I); 655286425Sdim } 656314564Sdim NodeVect::iterator NewE = remove_if(Nodes, in_set(Erase)); 657286425Sdim Nodes.resize(std::distance(Nodes.begin(), NewE)); 658286425Sdim 659286425Sdim DEBUG(dbgs() << "Gep nodes after post-commoning cleanup:\n" << Nodes); 660286425Sdim} 661286425Sdim 662314564Sdimtemplate <typename T> 663314564Sdimstatic BasicBlock *nearest_common_dominator(DominatorTree *DT, T &Blocks) { 664286425Sdim DEBUG({ 665286425Sdim dbgs() << "NCD of {"; 666286425Sdim for (typename T::iterator I = Blocks.begin(), E = Blocks.end(); 667286425Sdim I != E; ++I) { 668286425Sdim if (!*I) 669286425Sdim continue; 670286425Sdim BasicBlock *B = cast<BasicBlock>(*I); 671286425Sdim dbgs() << ' ' << B->getName(); 672286425Sdim } 673286425Sdim dbgs() << " }\n"; 674286425Sdim }); 675286425Sdim 676314564Sdim // Allow null basic blocks in Blocks. In such cases, return nullptr. 677286425Sdim typename T::iterator I = Blocks.begin(), E = Blocks.end(); 678286425Sdim if (I == E || !*I) 679314564Sdim return nullptr; 680286425Sdim BasicBlock *Dom = cast<BasicBlock>(*I); 681286425Sdim while (++I != E) { 682286425Sdim BasicBlock *B = cast_or_null<BasicBlock>(*I); 683314564Sdim Dom = B ? DT->findNearestCommonDominator(Dom, B) : nullptr; 684286425Sdim if (!Dom) 685314564Sdim return nullptr; 686286425Sdim } 687286425Sdim DEBUG(dbgs() << "computed:" << Dom->getName() << '\n'); 688286425Sdim return Dom; 689314564Sdim} 690286425Sdim 691314564Sdimtemplate <typename T> 692314564Sdimstatic BasicBlock *nearest_common_dominatee(DominatorTree *DT, T &Blocks) { 693286425Sdim // If two blocks, A and B, dominate a block C, then A dominates B, 694286425Sdim // or B dominates A. 695286425Sdim typename T::iterator I = Blocks.begin(), E = Blocks.end(); 696286425Sdim // Find the first non-null block. 697286425Sdim while (I != E && !*I) 698286425Sdim ++I; 699286425Sdim if (I == E) 700286425Sdim return DT->getRoot(); 701286425Sdim BasicBlock *DomB = cast<BasicBlock>(*I); 702286425Sdim while (++I != E) { 703286425Sdim if (!*I) 704286425Sdim continue; 705286425Sdim BasicBlock *B = cast<BasicBlock>(*I); 706286425Sdim if (DT->dominates(B, DomB)) 707286425Sdim continue; 708286425Sdim if (!DT->dominates(DomB, B)) 709314564Sdim return nullptr; 710286425Sdim DomB = B; 711286425Sdim } 712286425Sdim return DomB; 713314564Sdim} 714286425Sdim 715314564Sdim// Find the first use in B of any value from Values. If no such use, 716314564Sdim// return B->end(). 717314564Sdimtemplate <typename T> 718314564Sdimstatic BasicBlock::iterator first_use_of_in_block(T &Values, BasicBlock *B) { 719286425Sdim BasicBlock::iterator FirstUse = B->end(), BEnd = B->end(); 720286425Sdim typedef typename T::iterator iterator; 721286425Sdim for (iterator I = Values.begin(), E = Values.end(); I != E; ++I) { 722286425Sdim Value *V = *I; 723286425Sdim // If V is used in a PHI node, the use belongs to the incoming block, 724286425Sdim // not the block with the PHI node. In the incoming block, the use 725286425Sdim // would be considered as being at the end of it, so it cannot 726286425Sdim // influence the position of the first use (which is assumed to be 727286425Sdim // at the end to start with). 728286425Sdim if (isa<PHINode>(V)) 729286425Sdim continue; 730286425Sdim if (!isa<Instruction>(V)) 731286425Sdim continue; 732286425Sdim Instruction *In = cast<Instruction>(V); 733286425Sdim if (In->getParent() != B) 734286425Sdim continue; 735296417Sdim BasicBlock::iterator It = In->getIterator(); 736286425Sdim if (std::distance(FirstUse, BEnd) < std::distance(It, BEnd)) 737286425Sdim FirstUse = It; 738286425Sdim } 739286425Sdim return FirstUse; 740314564Sdim} 741286425Sdim 742314564Sdimstatic bool is_empty(const BasicBlock *B) { 743286425Sdim return B->empty() || (&*B->begin() == B->getTerminator()); 744286425Sdim} 745286425Sdim 746286425SdimBasicBlock *HexagonCommonGEP::recalculatePlacement(GepNode *Node, 747286425Sdim NodeChildrenMap &NCM, NodeToValueMap &Loc) { 748286425Sdim DEBUG(dbgs() << "Loc for node:" << Node << '\n'); 749286425Sdim // Recalculate the placement for Node, assuming that the locations of 750286425Sdim // its children in Loc are valid. 751314564Sdim // Return nullptr if there is no valid placement for Node (for example, it 752286425Sdim // uses an index value that is not available at the location required 753286425Sdim // to dominate all children, etc.). 754286425Sdim 755286425Sdim // Find the nearest common dominator for: 756286425Sdim // - all users, if the node is used, and 757286425Sdim // - all children. 758286425Sdim ValueVect Bs; 759286425Sdim if (Node->Flags & GepNode::Used) { 760286425Sdim // Append all blocks with uses of the original values to the 761286425Sdim // block vector Bs. 762286425Sdim NodeToUsesMap::iterator UF = Uses.find(Node); 763286425Sdim assert(UF != Uses.end() && "Used node with no use information"); 764286425Sdim UseSet &Us = UF->second; 765286425Sdim for (UseSet::iterator I = Us.begin(), E = Us.end(); I != E; ++I) { 766286425Sdim Use *U = *I; 767286425Sdim User *R = U->getUser(); 768286425Sdim if (!isa<Instruction>(R)) 769286425Sdim continue; 770286425Sdim BasicBlock *PB = isa<PHINode>(R) 771286425Sdim ? cast<PHINode>(R)->getIncomingBlock(*U) 772286425Sdim : cast<Instruction>(R)->getParent(); 773286425Sdim Bs.push_back(PB); 774286425Sdim } 775286425Sdim } 776286425Sdim // Append the location of each child. 777286425Sdim NodeChildrenMap::iterator CF = NCM.find(Node); 778286425Sdim if (CF != NCM.end()) { 779286425Sdim NodeVect &Cs = CF->second; 780286425Sdim for (NodeVect::iterator I = Cs.begin(), E = Cs.end(); I != E; ++I) { 781286425Sdim GepNode *CN = *I; 782286425Sdim NodeToValueMap::iterator LF = Loc.find(CN); 783286425Sdim // If the child is only used in GEP instructions (i.e. is not used in 784286425Sdim // non-GEP instructions), the nearest dominator computed for it may 785286425Sdim // have been null. In such case it won't have a location available. 786286425Sdim if (LF == Loc.end()) 787286425Sdim continue; 788286425Sdim Bs.push_back(LF->second); 789286425Sdim } 790286425Sdim } 791286425Sdim 792286425Sdim BasicBlock *DomB = nearest_common_dominator(DT, Bs); 793286425Sdim if (!DomB) 794314564Sdim return nullptr; 795286425Sdim // Check if the index used by Node dominates the computed dominator. 796286425Sdim Instruction *IdxI = dyn_cast<Instruction>(Node->Idx); 797286425Sdim if (IdxI && !DT->dominates(IdxI->getParent(), DomB)) 798314564Sdim return nullptr; 799286425Sdim 800286425Sdim // Avoid putting nodes into empty blocks. 801286425Sdim while (is_empty(DomB)) { 802286425Sdim DomTreeNode *N = (*DT)[DomB]->getIDom(); 803286425Sdim if (!N) 804286425Sdim break; 805286425Sdim DomB = N->getBlock(); 806286425Sdim } 807286425Sdim 808286425Sdim // Otherwise, DomB is fine. Update the location map. 809286425Sdim Loc[Node] = DomB; 810286425Sdim return DomB; 811286425Sdim} 812286425Sdim 813286425SdimBasicBlock *HexagonCommonGEP::recalculatePlacementRec(GepNode *Node, 814286425Sdim NodeChildrenMap &NCM, NodeToValueMap &Loc) { 815286425Sdim DEBUG(dbgs() << "LocRec begin for node:" << Node << '\n'); 816286425Sdim // Recalculate the placement of Node, after recursively recalculating the 817286425Sdim // placements of all its children. 818286425Sdim NodeChildrenMap::iterator CF = NCM.find(Node); 819286425Sdim if (CF != NCM.end()) { 820286425Sdim NodeVect &Cs = CF->second; 821286425Sdim for (NodeVect::iterator I = Cs.begin(), E = Cs.end(); I != E; ++I) 822286425Sdim recalculatePlacementRec(*I, NCM, Loc); 823286425Sdim } 824286425Sdim BasicBlock *LB = recalculatePlacement(Node, NCM, Loc); 825286425Sdim DEBUG(dbgs() << "LocRec end for node:" << Node << '\n'); 826286425Sdim return LB; 827286425Sdim} 828286425Sdim 829286425Sdimbool HexagonCommonGEP::isInvariantIn(Value *Val, Loop *L) { 830286425Sdim if (isa<Constant>(Val) || isa<Argument>(Val)) 831286425Sdim return true; 832286425Sdim Instruction *In = dyn_cast<Instruction>(Val); 833286425Sdim if (!In) 834286425Sdim return false; 835286425Sdim BasicBlock *HdrB = L->getHeader(), *DefB = In->getParent(); 836286425Sdim return DT->properlyDominates(DefB, HdrB); 837286425Sdim} 838286425Sdim 839286425Sdimbool HexagonCommonGEP::isInvariantIn(GepNode *Node, Loop *L) { 840286425Sdim if (Node->Flags & GepNode::Root) 841286425Sdim if (!isInvariantIn(Node->BaseVal, L)) 842286425Sdim return false; 843286425Sdim return isInvariantIn(Node->Idx, L); 844286425Sdim} 845286425Sdim 846286425Sdimbool HexagonCommonGEP::isInMainPath(BasicBlock *B, Loop *L) { 847286425Sdim BasicBlock *HB = L->getHeader(); 848286425Sdim BasicBlock *LB = L->getLoopLatch(); 849286425Sdim // B must post-dominate the loop header or dominate the loop latch. 850286425Sdim if (PDT->dominates(B, HB)) 851286425Sdim return true; 852286425Sdim if (LB && DT->dominates(B, LB)) 853286425Sdim return true; 854286425Sdim return false; 855286425Sdim} 856286425Sdim 857314564Sdimstatic BasicBlock *preheader(DominatorTree *DT, Loop *L) { 858314564Sdim if (BasicBlock *PH = L->getLoopPreheader()) 859314564Sdim return PH; 860314564Sdim if (!OptSpeculate) 861314564Sdim return nullptr; 862314564Sdim DomTreeNode *DN = DT->getNode(L->getHeader()); 863314564Sdim if (!DN) 864314564Sdim return nullptr; 865314564Sdim return DN->getIDom()->getBlock(); 866286425Sdim} 867286425Sdim 868286425SdimBasicBlock *HexagonCommonGEP::adjustForInvariance(GepNode *Node, 869286425Sdim NodeChildrenMap &NCM, NodeToValueMap &Loc) { 870286425Sdim // Find the "topmost" location for Node: it must be dominated by both, 871286425Sdim // its parent (or the BaseVal, if it's a root node), and by the index 872286425Sdim // value. 873286425Sdim ValueVect Bs; 874286425Sdim if (Node->Flags & GepNode::Root) { 875286425Sdim if (Instruction *PIn = dyn_cast<Instruction>(Node->BaseVal)) 876286425Sdim Bs.push_back(PIn->getParent()); 877286425Sdim } else { 878286425Sdim Bs.push_back(Loc[Node->Parent]); 879286425Sdim } 880286425Sdim if (Instruction *IIn = dyn_cast<Instruction>(Node->Idx)) 881286425Sdim Bs.push_back(IIn->getParent()); 882286425Sdim BasicBlock *TopB = nearest_common_dominatee(DT, Bs); 883286425Sdim 884286425Sdim // Traverse the loop nest upwards until we find a loop in which Node 885286425Sdim // is no longer invariant, or until we get to the upper limit of Node's 886286425Sdim // placement. The traversal will also stop when a suitable "preheader" 887286425Sdim // cannot be found for a given loop. The "preheader" may actually be 888286425Sdim // a regular block outside of the loop (i.e. not guarded), in which case 889286425Sdim // the Node will be speculated. 890286425Sdim // For nodes that are not in the main path of the containing loop (i.e. 891286425Sdim // are not executed in each iteration), do not move them out of the loop. 892286425Sdim BasicBlock *LocB = cast_or_null<BasicBlock>(Loc[Node]); 893286425Sdim if (LocB) { 894286425Sdim Loop *Lp = LI->getLoopFor(LocB); 895286425Sdim while (Lp) { 896286425Sdim if (!isInvariantIn(Node, Lp) || !isInMainPath(LocB, Lp)) 897286425Sdim break; 898286425Sdim BasicBlock *NewLoc = preheader(DT, Lp); 899286425Sdim if (!NewLoc || !DT->dominates(TopB, NewLoc)) 900286425Sdim break; 901286425Sdim Lp = Lp->getParentLoop(); 902286425Sdim LocB = NewLoc; 903286425Sdim } 904286425Sdim } 905286425Sdim Loc[Node] = LocB; 906286425Sdim 907286425Sdim // Recursively compute the locations of all children nodes. 908286425Sdim NodeChildrenMap::iterator CF = NCM.find(Node); 909286425Sdim if (CF != NCM.end()) { 910286425Sdim NodeVect &Cs = CF->second; 911286425Sdim for (NodeVect::iterator I = Cs.begin(), E = Cs.end(); I != E; ++I) 912286425Sdim adjustForInvariance(*I, NCM, Loc); 913286425Sdim } 914286425Sdim return LocB; 915286425Sdim} 916286425Sdim 917314564Sdimnamespace { 918286425Sdim 919286425Sdim struct LocationAsBlock { 920286425Sdim LocationAsBlock(const NodeToValueMap &L) : Map(L) {} 921314564Sdim 922286425Sdim const NodeToValueMap ⤅ 923286425Sdim }; 924286425Sdim 925286425Sdim raw_ostream &operator<< (raw_ostream &OS, 926286425Sdim const LocationAsBlock &Loc) LLVM_ATTRIBUTE_UNUSED ; 927286425Sdim raw_ostream &operator<< (raw_ostream &OS, const LocationAsBlock &Loc) { 928286425Sdim for (NodeToValueMap::const_iterator I = Loc.Map.begin(), E = Loc.Map.end(); 929286425Sdim I != E; ++I) { 930286425Sdim OS << I->first << " -> "; 931286425Sdim BasicBlock *B = cast<BasicBlock>(I->second); 932286425Sdim OS << B->getName() << '(' << B << ')'; 933286425Sdim OS << '\n'; 934286425Sdim } 935286425Sdim return OS; 936286425Sdim } 937286425Sdim 938286425Sdim inline bool is_constant(GepNode *N) { 939286425Sdim return isa<ConstantInt>(N->Idx); 940286425Sdim } 941286425Sdim 942314564Sdim} // end anonymous namespace 943286425Sdim 944286425Sdimvoid HexagonCommonGEP::separateChainForNode(GepNode *Node, Use *U, 945286425Sdim NodeToValueMap &Loc) { 946286425Sdim User *R = U->getUser(); 947286425Sdim DEBUG(dbgs() << "Separating chain for node (" << Node << ") user: " 948286425Sdim << *R << '\n'); 949286425Sdim BasicBlock *PB = cast<Instruction>(R)->getParent(); 950286425Sdim 951286425Sdim GepNode *N = Node; 952314564Sdim GepNode *C = nullptr, *NewNode = nullptr; 953286425Sdim while (is_constant(N) && !(N->Flags & GepNode::Root)) { 954286425Sdim // XXX if (single-use) dont-replicate; 955286425Sdim GepNode *NewN = new (*Mem) GepNode(N); 956286425Sdim Nodes.push_back(NewN); 957286425Sdim Loc[NewN] = PB; 958286425Sdim 959286425Sdim if (N == Node) 960286425Sdim NewNode = NewN; 961286425Sdim NewN->Flags &= ~GepNode::Used; 962286425Sdim if (C) 963286425Sdim C->Parent = NewN; 964286425Sdim C = NewN; 965286425Sdim N = N->Parent; 966286425Sdim } 967286425Sdim if (!NewNode) 968286425Sdim return; 969286425Sdim 970286425Sdim // Move over all uses that share the same user as U from Node to NewNode. 971286425Sdim NodeToUsesMap::iterator UF = Uses.find(Node); 972286425Sdim assert(UF != Uses.end()); 973286425Sdim UseSet &Us = UF->second; 974286425Sdim UseSet NewUs; 975286425Sdim for (UseSet::iterator I = Us.begin(); I != Us.end(); ) { 976286425Sdim User *S = (*I)->getUser(); 977286425Sdim UseSet::iterator Nx = std::next(I); 978286425Sdim if (S == R) { 979286425Sdim NewUs.insert(*I); 980286425Sdim Us.erase(I); 981286425Sdim } 982286425Sdim I = Nx; 983286425Sdim } 984286425Sdim if (Us.empty()) { 985286425Sdim Node->Flags &= ~GepNode::Used; 986286425Sdim Uses.erase(UF); 987286425Sdim } 988286425Sdim 989286425Sdim // Should at least have U in NewUs. 990286425Sdim NewNode->Flags |= GepNode::Used; 991286425Sdim DEBUG(dbgs() << "new node: " << NewNode << " " << *NewNode << '\n'); 992286425Sdim assert(!NewUs.empty()); 993286425Sdim Uses[NewNode] = NewUs; 994286425Sdim} 995286425Sdim 996286425Sdimvoid HexagonCommonGEP::separateConstantChains(GepNode *Node, 997286425Sdim NodeChildrenMap &NCM, NodeToValueMap &Loc) { 998286425Sdim // First approximation: extract all chains. 999286425Sdim NodeSet Ns; 1000286425Sdim nodes_for_root(Node, NCM, Ns); 1001286425Sdim 1002286425Sdim DEBUG(dbgs() << "Separating constant chains for node: " << Node << '\n'); 1003286425Sdim // Collect all used nodes together with the uses from loads and stores, 1004286425Sdim // where the GEP node could be folded into the load/store instruction. 1005286425Sdim NodeToUsesMap FNs; // Foldable nodes. 1006286425Sdim for (NodeSet::iterator I = Ns.begin(), E = Ns.end(); I != E; ++I) { 1007286425Sdim GepNode *N = *I; 1008286425Sdim if (!(N->Flags & GepNode::Used)) 1009286425Sdim continue; 1010286425Sdim NodeToUsesMap::iterator UF = Uses.find(N); 1011286425Sdim assert(UF != Uses.end()); 1012286425Sdim UseSet &Us = UF->second; 1013286425Sdim // Loads/stores that use the node N. 1014286425Sdim UseSet LSs; 1015286425Sdim for (UseSet::iterator J = Us.begin(), F = Us.end(); J != F; ++J) { 1016286425Sdim Use *U = *J; 1017286425Sdim User *R = U->getUser(); 1018286425Sdim // We're interested in uses that provide the address. It can happen 1019286425Sdim // that the value may also be provided via GEP, but we won't handle 1020286425Sdim // those cases here for now. 1021286425Sdim if (LoadInst *Ld = dyn_cast<LoadInst>(R)) { 1022286425Sdim unsigned PtrX = LoadInst::getPointerOperandIndex(); 1023286425Sdim if (&Ld->getOperandUse(PtrX) == U) 1024286425Sdim LSs.insert(U); 1025286425Sdim } else if (StoreInst *St = dyn_cast<StoreInst>(R)) { 1026286425Sdim unsigned PtrX = StoreInst::getPointerOperandIndex(); 1027286425Sdim if (&St->getOperandUse(PtrX) == U) 1028286425Sdim LSs.insert(U); 1029286425Sdim } 1030286425Sdim } 1031286425Sdim // Even if the total use count is 1, separating the chain may still be 1032286425Sdim // beneficial, since the constant chain may be longer than the GEP alone 1033286425Sdim // would be (e.g. if the parent node has a constant index and also has 1034286425Sdim // other children). 1035286425Sdim if (!LSs.empty()) 1036286425Sdim FNs.insert(std::make_pair(N, LSs)); 1037286425Sdim } 1038286425Sdim 1039286425Sdim DEBUG(dbgs() << "Nodes with foldable users:\n" << FNs); 1040286425Sdim 1041286425Sdim for (NodeToUsesMap::iterator I = FNs.begin(), E = FNs.end(); I != E; ++I) { 1042286425Sdim GepNode *N = I->first; 1043286425Sdim UseSet &Us = I->second; 1044286425Sdim for (UseSet::iterator J = Us.begin(), F = Us.end(); J != F; ++J) 1045286425Sdim separateChainForNode(N, *J, Loc); 1046286425Sdim } 1047286425Sdim} 1048286425Sdim 1049286425Sdimvoid HexagonCommonGEP::computeNodePlacement(NodeToValueMap &Loc) { 1050286425Sdim // Compute the inverse of the Node.Parent links. Also, collect the set 1051286425Sdim // of root nodes. 1052286425Sdim NodeChildrenMap NCM; 1053286425Sdim NodeVect Roots; 1054286425Sdim invert_find_roots(Nodes, NCM, Roots); 1055286425Sdim 1056286425Sdim // Compute the initial placement determined by the users' locations, and 1057286425Sdim // the locations of the child nodes. 1058286425Sdim for (NodeVect::iterator I = Roots.begin(), E = Roots.end(); I != E; ++I) 1059286425Sdim recalculatePlacementRec(*I, NCM, Loc); 1060286425Sdim 1061286425Sdim DEBUG(dbgs() << "Initial node placement:\n" << LocationAsBlock(Loc)); 1062286425Sdim 1063286425Sdim if (OptEnableInv) { 1064286425Sdim for (NodeVect::iterator I = Roots.begin(), E = Roots.end(); I != E; ++I) 1065286425Sdim adjustForInvariance(*I, NCM, Loc); 1066286425Sdim 1067286425Sdim DEBUG(dbgs() << "Node placement after adjustment for invariance:\n" 1068286425Sdim << LocationAsBlock(Loc)); 1069286425Sdim } 1070286425Sdim if (OptEnableConst) { 1071286425Sdim for (NodeVect::iterator I = Roots.begin(), E = Roots.end(); I != E; ++I) 1072286425Sdim separateConstantChains(*I, NCM, Loc); 1073286425Sdim } 1074286425Sdim DEBUG(dbgs() << "Node use information:\n" << Uses); 1075286425Sdim 1076286425Sdim // At the moment, there is no further refinement of the initial placement. 1077286425Sdim // Such a refinement could include splitting the nodes if they are placed 1078286425Sdim // too far from some of its users. 1079286425Sdim 1080286425Sdim DEBUG(dbgs() << "Final node placement:\n" << LocationAsBlock(Loc)); 1081286425Sdim} 1082286425Sdim 1083286425SdimValue *HexagonCommonGEP::fabricateGEP(NodeVect &NA, BasicBlock::iterator At, 1084286425Sdim BasicBlock *LocB) { 1085286425Sdim DEBUG(dbgs() << "Fabricating GEP in " << LocB->getName() 1086286425Sdim << " for nodes:\n" << NA); 1087286425Sdim unsigned Num = NA.size(); 1088286425Sdim GepNode *RN = NA[0]; 1089286425Sdim assert((RN->Flags & GepNode::Root) && "Creating GEP for non-root"); 1090286425Sdim 1091321369Sdim GetElementPtrInst *NewInst = nullptr; 1092286425Sdim Value *Input = RN->BaseVal; 1093286425Sdim Value **IdxList = new Value*[Num+1]; 1094286425Sdim unsigned nax = 0; 1095286425Sdim do { 1096286425Sdim unsigned IdxC = 0; 1097286425Sdim // If the type of the input of the first node is not a pointer, 1098286425Sdim // we need to add an artificial i32 0 to the indices (because the 1099286425Sdim // actual input in the IR will be a pointer). 1100286425Sdim if (!NA[nax]->PTy->isPointerTy()) { 1101286425Sdim Type *Int32Ty = Type::getInt32Ty(*Ctx); 1102286425Sdim IdxList[IdxC++] = ConstantInt::get(Int32Ty, 0); 1103286425Sdim } 1104286425Sdim 1105286425Sdim // Keep adding indices from NA until we have to stop and generate 1106286425Sdim // an "intermediate" GEP. 1107286425Sdim while (++nax <= Num) { 1108286425Sdim GepNode *N = NA[nax-1]; 1109286425Sdim IdxList[IdxC++] = N->Idx; 1110286425Sdim if (nax < Num) { 1111286425Sdim // We have to stop, if the expected type of the output of this node 1112286425Sdim // is not the same as the input type of the next node. 1113286425Sdim Type *NextTy = next_type(N->PTy, N->Idx); 1114286425Sdim if (NextTy != NA[nax]->PTy) 1115286425Sdim break; 1116286425Sdim } 1117286425Sdim } 1118286425Sdim ArrayRef<Value*> A(IdxList, IdxC); 1119286425Sdim Type *InpTy = Input->getType(); 1120286425Sdim Type *ElTy = cast<PointerType>(InpTy->getScalarType())->getElementType(); 1121296417Sdim NewInst = GetElementPtrInst::Create(ElTy, Input, A, "cgep", &*At); 1122321369Sdim NewInst->setIsInBounds(RN->Flags & GepNode::InBounds); 1123286425Sdim DEBUG(dbgs() << "new GEP: " << *NewInst << '\n'); 1124286425Sdim Input = NewInst; 1125286425Sdim } while (nax <= Num); 1126286425Sdim 1127286425Sdim delete[] IdxList; 1128286425Sdim return NewInst; 1129286425Sdim} 1130286425Sdim 1131286425Sdimvoid HexagonCommonGEP::getAllUsersForNode(GepNode *Node, ValueVect &Values, 1132286425Sdim NodeChildrenMap &NCM) { 1133286425Sdim NodeVect Work; 1134286425Sdim Work.push_back(Node); 1135286425Sdim 1136286425Sdim while (!Work.empty()) { 1137286425Sdim NodeVect::iterator First = Work.begin(); 1138286425Sdim GepNode *N = *First; 1139286425Sdim Work.erase(First); 1140286425Sdim if (N->Flags & GepNode::Used) { 1141286425Sdim NodeToUsesMap::iterator UF = Uses.find(N); 1142286425Sdim assert(UF != Uses.end() && "No use information for used node"); 1143286425Sdim UseSet &Us = UF->second; 1144286425Sdim for (UseSet::iterator I = Us.begin(), E = Us.end(); I != E; ++I) 1145286425Sdim Values.push_back((*I)->getUser()); 1146286425Sdim } 1147286425Sdim NodeChildrenMap::iterator CF = NCM.find(N); 1148286425Sdim if (CF != NCM.end()) { 1149286425Sdim NodeVect &Cs = CF->second; 1150286425Sdim Work.insert(Work.end(), Cs.begin(), Cs.end()); 1151286425Sdim } 1152286425Sdim } 1153286425Sdim} 1154286425Sdim 1155286425Sdimvoid HexagonCommonGEP::materialize(NodeToValueMap &Loc) { 1156286425Sdim DEBUG(dbgs() << "Nodes before materialization:\n" << Nodes << '\n'); 1157286425Sdim NodeChildrenMap NCM; 1158286425Sdim NodeVect Roots; 1159286425Sdim // Compute the inversion again, since computing placement could alter 1160286425Sdim // "parent" relation between nodes. 1161286425Sdim invert_find_roots(Nodes, NCM, Roots); 1162286425Sdim 1163286425Sdim while (!Roots.empty()) { 1164286425Sdim NodeVect::iterator First = Roots.begin(); 1165286425Sdim GepNode *Root = *First, *Last = *First; 1166286425Sdim Roots.erase(First); 1167286425Sdim 1168286425Sdim NodeVect NA; // Nodes to assemble. 1169286425Sdim // Append to NA all child nodes up to (and including) the first child 1170286425Sdim // that: 1171286425Sdim // (1) has more than 1 child, or 1172286425Sdim // (2) is used, or 1173286425Sdim // (3) has a child located in a different block. 1174286425Sdim bool LastUsed = false; 1175286425Sdim unsigned LastCN = 0; 1176286425Sdim // The location may be null if the computation failed (it can legitimately 1177286425Sdim // happen for nodes created from dead GEPs). 1178286425Sdim Value *LocV = Loc[Last]; 1179286425Sdim if (!LocV) 1180286425Sdim continue; 1181286425Sdim BasicBlock *LastB = cast<BasicBlock>(LocV); 1182286425Sdim do { 1183286425Sdim NA.push_back(Last); 1184286425Sdim LastUsed = (Last->Flags & GepNode::Used); 1185286425Sdim if (LastUsed) 1186286425Sdim break; 1187286425Sdim NodeChildrenMap::iterator CF = NCM.find(Last); 1188286425Sdim LastCN = (CF != NCM.end()) ? CF->second.size() : 0; 1189286425Sdim if (LastCN != 1) 1190286425Sdim break; 1191286425Sdim GepNode *Child = CF->second.front(); 1192286425Sdim BasicBlock *ChildB = cast_or_null<BasicBlock>(Loc[Child]); 1193314564Sdim if (ChildB != nullptr && LastB != ChildB) 1194286425Sdim break; 1195286425Sdim Last = Child; 1196286425Sdim } while (true); 1197286425Sdim 1198296417Sdim BasicBlock::iterator InsertAt = LastB->getTerminator()->getIterator(); 1199286425Sdim if (LastUsed || LastCN > 0) { 1200286425Sdim ValueVect Urs; 1201286425Sdim getAllUsersForNode(Root, Urs, NCM); 1202286425Sdim BasicBlock::iterator FirstUse = first_use_of_in_block(Urs, LastB); 1203286425Sdim if (FirstUse != LastB->end()) 1204286425Sdim InsertAt = FirstUse; 1205286425Sdim } 1206286425Sdim 1207286425Sdim // Generate a new instruction for NA. 1208286425Sdim Value *NewInst = fabricateGEP(NA, InsertAt, LastB); 1209286425Sdim 1210286425Sdim // Convert all the children of Last node into roots, and append them 1211286425Sdim // to the Roots list. 1212286425Sdim if (LastCN > 0) { 1213286425Sdim NodeVect &Cs = NCM[Last]; 1214286425Sdim for (NodeVect::iterator I = Cs.begin(), E = Cs.end(); I != E; ++I) { 1215286425Sdim GepNode *CN = *I; 1216286425Sdim CN->Flags &= ~GepNode::Internal; 1217286425Sdim CN->Flags |= GepNode::Root; 1218286425Sdim CN->BaseVal = NewInst; 1219286425Sdim Roots.push_back(CN); 1220286425Sdim } 1221286425Sdim } 1222286425Sdim 1223286425Sdim // Lastly, if the Last node was used, replace all uses with the new GEP. 1224286425Sdim // The uses reference the original GEP values. 1225286425Sdim if (LastUsed) { 1226286425Sdim NodeToUsesMap::iterator UF = Uses.find(Last); 1227286425Sdim assert(UF != Uses.end() && "No use information found"); 1228286425Sdim UseSet &Us = UF->second; 1229286425Sdim for (UseSet::iterator I = Us.begin(), E = Us.end(); I != E; ++I) { 1230286425Sdim Use *U = *I; 1231286425Sdim U->set(NewInst); 1232286425Sdim } 1233286425Sdim } 1234286425Sdim } 1235286425Sdim} 1236286425Sdim 1237286425Sdimvoid HexagonCommonGEP::removeDeadCode() { 1238286425Sdim ValueVect BO; 1239286425Sdim BO.push_back(&Fn->front()); 1240286425Sdim 1241286425Sdim for (unsigned i = 0; i < BO.size(); ++i) { 1242286425Sdim BasicBlock *B = cast<BasicBlock>(BO[i]); 1243321369Sdim for (auto DTN : children<DomTreeNode*>(DT->getNode(B))) 1244321369Sdim BO.push_back(DTN->getBlock()); 1245286425Sdim } 1246286425Sdim 1247286425Sdim for (unsigned i = BO.size(); i > 0; --i) { 1248286425Sdim BasicBlock *B = cast<BasicBlock>(BO[i-1]); 1249286425Sdim BasicBlock::InstListType &IL = B->getInstList(); 1250286425Sdim typedef BasicBlock::InstListType::reverse_iterator reverse_iterator; 1251286425Sdim ValueVect Ins; 1252286425Sdim for (reverse_iterator I = IL.rbegin(), E = IL.rend(); I != E; ++I) 1253286425Sdim Ins.push_back(&*I); 1254286425Sdim for (ValueVect::iterator I = Ins.begin(), E = Ins.end(); I != E; ++I) { 1255286425Sdim Instruction *In = cast<Instruction>(*I); 1256286425Sdim if (isInstructionTriviallyDead(In)) 1257286425Sdim In->eraseFromParent(); 1258286425Sdim } 1259286425Sdim } 1260286425Sdim} 1261286425Sdim 1262286425Sdimbool HexagonCommonGEP::runOnFunction(Function &F) { 1263309124Sdim if (skipFunction(F)) 1264309124Sdim return false; 1265309124Sdim 1266286425Sdim // For now bail out on C++ exception handling. 1267286425Sdim for (Function::iterator A = F.begin(), Z = F.end(); A != Z; ++A) 1268286425Sdim for (BasicBlock::iterator I = A->begin(), E = A->end(); I != E; ++I) 1269286425Sdim if (isa<InvokeInst>(I) || isa<LandingPadInst>(I)) 1270286425Sdim return false; 1271286425Sdim 1272286425Sdim Fn = &F; 1273286425Sdim DT = &getAnalysis<DominatorTreeWrapperPass>().getDomTree(); 1274309124Sdim PDT = &getAnalysis<PostDominatorTreeWrapperPass>().getPostDomTree(); 1275286425Sdim LI = &getAnalysis<LoopInfoWrapperPass>().getLoopInfo(); 1276286425Sdim Ctx = &F.getContext(); 1277286425Sdim 1278286425Sdim Nodes.clear(); 1279286425Sdim Uses.clear(); 1280286425Sdim NodeOrder.clear(); 1281286425Sdim 1282286425Sdim SpecificBumpPtrAllocator<GepNode> Allocator; 1283286425Sdim Mem = &Allocator; 1284286425Sdim 1285286425Sdim collect(); 1286286425Sdim common(); 1287286425Sdim 1288286425Sdim NodeToValueMap Loc; 1289286425Sdim computeNodePlacement(Loc); 1290286425Sdim materialize(Loc); 1291286425Sdim removeDeadCode(); 1292286425Sdim 1293309124Sdim#ifdef EXPENSIVE_CHECKS 1294286425Sdim // Run this only when expensive checks are enabled. 1295286425Sdim verifyFunction(F); 1296286425Sdim#endif 1297286425Sdim return true; 1298286425Sdim} 1299286425Sdim 1300314564Sdimnamespace llvm { 1301286425Sdim 1302286425Sdim FunctionPass *createHexagonCommonGEP() { 1303286425Sdim return new HexagonCommonGEP(); 1304286425Sdim } 1305314564Sdim 1306314564Sdim} // end namespace llvm 1307