LoopVectorize.cpp revision 249423
1243789Sdim//===- LoopVectorize.cpp - A Loop Vectorizer ------------------------------===// 2243789Sdim// 3243789Sdim// The LLVM Compiler Infrastructure 4243789Sdim// 5243789Sdim// This file is distributed under the University of Illinois Open Source 6243789Sdim// License. See LICENSE.TXT for details. 7243789Sdim// 8243789Sdim//===----------------------------------------------------------------------===// 9243789Sdim// 10243789Sdim// This is the LLVM loop vectorizer. This pass modifies 'vectorizable' loops 11243789Sdim// and generates target-independent LLVM-IR. Legalization of the IR is done 12249423Sdim// in the codegen. However, the vectorizer uses (will use) the codegen 13243789Sdim// interfaces to generate IR that is likely to result in an optimal binary. 14243789Sdim// 15249423Sdim// The loop vectorizer combines consecutive loop iterations into a single 16243789Sdim// 'wide' iteration. After this transformation the index is incremented 17243789Sdim// by the SIMD vector width, and not by one. 18243789Sdim// 19243789Sdim// This pass has three parts: 20243789Sdim// 1. The main loop pass that drives the different parts. 21243789Sdim// 2. LoopVectorizationLegality - A unit that checks for the legality 22243789Sdim// of the vectorization. 23249423Sdim// 3. InnerLoopVectorizer - A unit that performs the actual 24243789Sdim// widening of instructions. 25243789Sdim// 4. LoopVectorizationCostModel - A unit that checks for the profitability 26243789Sdim// of vectorization. It decides on the optimal vector width, which 27243789Sdim// can be one, if vectorization is not profitable. 28249423Sdim// 29243789Sdim//===----------------------------------------------------------------------===// 30243789Sdim// 31243789Sdim// The reduction-variable vectorization is based on the paper: 32243789Sdim// D. Nuzman and R. Henderson. Multi-platform Auto-vectorization. 33243789Sdim// 34243789Sdim// Variable uniformity checks are inspired by: 35249423Sdim// Karrenberg, R. and Hack, S. Whole Function Vectorization. 36243789Sdim// 37243789Sdim// Other ideas/concepts are from: 38243789Sdim// A. Zaks and D. Nuzman. Autovectorization in GCC-two years later. 39243789Sdim// 40249423Sdim// S. Maleki, Y. Gao, M. Garzaran, T. Wong and D. Padua. An Evaluation of 41249423Sdim// Vectorizing Compilers. 42249423Sdim// 43243789Sdim//===----------------------------------------------------------------------===// 44249423Sdim 45243789Sdim#define LV_NAME "loop-vectorize" 46243789Sdim#define DEBUG_TYPE LV_NAME 47249423Sdim 48249423Sdim#include "llvm/Transforms/Vectorize.h" 49249423Sdim#include "llvm/ADT/DenseMap.h" 50249423Sdim#include "llvm/ADT/MapVector.h" 51249423Sdim#include "llvm/ADT/SmallPtrSet.h" 52249423Sdim#include "llvm/ADT/SmallSet.h" 53243789Sdim#include "llvm/ADT/SmallVector.h" 54243789Sdim#include "llvm/ADT/StringExtras.h" 55243789Sdim#include "llvm/Analysis/AliasAnalysis.h" 56243789Sdim#include "llvm/Analysis/AliasSetTracker.h" 57249423Sdim#include "llvm/Analysis/Dominators.h" 58249423Sdim#include "llvm/Analysis/LoopInfo.h" 59249423Sdim#include "llvm/Analysis/LoopIterator.h" 60249423Sdim#include "llvm/Analysis/LoopPass.h" 61243789Sdim#include "llvm/Analysis/ScalarEvolution.h" 62249423Sdim#include "llvm/Analysis/ScalarEvolutionExpander.h" 63243789Sdim#include "llvm/Analysis/ScalarEvolutionExpressions.h" 64249423Sdim#include "llvm/Analysis/TargetTransformInfo.h" 65243789Sdim#include "llvm/Analysis/ValueTracking.h" 66249423Sdim#include "llvm/Analysis/Verifier.h" 67249423Sdim#include "llvm/IR/Constants.h" 68249423Sdim#include "llvm/IR/DataLayout.h" 69249423Sdim#include "llvm/IR/DerivedTypes.h" 70249423Sdim#include "llvm/IR/Function.h" 71249423Sdim#include "llvm/IR/IRBuilder.h" 72249423Sdim#include "llvm/IR/Instructions.h" 73249423Sdim#include "llvm/IR/IntrinsicInst.h" 74249423Sdim#include "llvm/IR/LLVMContext.h" 75249423Sdim#include "llvm/IR/Module.h" 76249423Sdim#include "llvm/IR/Type.h" 77249423Sdim#include "llvm/IR/Value.h" 78249423Sdim#include "llvm/Pass.h" 79243789Sdim#include "llvm/Support/CommandLine.h" 80243789Sdim#include "llvm/Support/Debug.h" 81243789Sdim#include "llvm/Support/raw_ostream.h" 82249423Sdim#include "llvm/Target/TargetLibraryInfo.h" 83249423Sdim#include "llvm/Transforms/Scalar.h" 84249423Sdim#include "llvm/Transforms/Utils/BasicBlockUtils.h" 85243789Sdim#include "llvm/Transforms/Utils/Local.h" 86243789Sdim#include <algorithm> 87249423Sdim#include <map> 88249423Sdim 89243789Sdimusing namespace llvm; 90243789Sdim 91243789Sdimstatic cl::opt<unsigned> 92243789SdimVectorizationFactor("force-vector-width", cl::init(0), cl::Hidden, 93249423Sdim cl::desc("Sets the SIMD width. Zero is autoselect.")); 94243789Sdim 95249423Sdimstatic cl::opt<unsigned> 96249423SdimVectorizationUnroll("force-vector-unroll", cl::init(0), cl::Hidden, 97249423Sdim cl::desc("Sets the vectorization unroll count. " 98249423Sdim "Zero is autoselect.")); 99249423Sdim 100249423Sdimstatic cl::opt<bool> 101249423SdimEnableIfConversion("enable-if-conversion", cl::init(true), cl::Hidden, 102249423Sdim cl::desc("Enable if-conversion during vectorization.")); 103249423Sdim 104243789Sdim/// We don't vectorize loops with a known constant trip count below this number. 105249423Sdimstatic cl::opt<unsigned> 106249423SdimTinyTripCountVectorThreshold("vectorizer-min-trip-count", cl::init(16), 107249423Sdim cl::Hidden, 108249423Sdim cl::desc("Don't vectorize loops with a constant " 109249423Sdim "trip count that is smaller than this " 110249423Sdim "value.")); 111243789Sdim 112249423Sdim/// We don't unroll loops with a known constant trip count below this number. 113249423Sdimstatic const unsigned TinyTripCountUnrollThreshold = 128; 114249423Sdim 115243789Sdim/// When performing a runtime memory check, do not check more than this 116243789Sdim/// number of pointers. Notice that the check is quadratic! 117249423Sdimstatic const unsigned RuntimeMemoryCheckThreshold = 4; 118243789Sdim 119249423Sdim/// We use a metadata with this name to indicate that a scalar loop was 120249423Sdim/// vectorized and that we don't need to re-vectorize it if we run into it 121249423Sdim/// again. 122249423Sdimstatic const char* 123249423SdimAlreadyVectorizedMDName = "llvm.vectorizer.already_vectorized"; 124249423Sdim 125243789Sdimnamespace { 126243789Sdim 127243789Sdim// Forward declarations. 128243789Sdimclass LoopVectorizationLegality; 129243789Sdimclass LoopVectorizationCostModel; 130243789Sdim 131249423Sdim/// InnerLoopVectorizer vectorizes loops which contain only one basic 132243789Sdim/// block to a specified vectorization factor (VF). 133243789Sdim/// This class performs the widening of scalars into vectors, or multiple 134243789Sdim/// scalars. This class also implements the following features: 135243789Sdim/// * It inserts an epilogue loop for handling loops that don't have iteration 136243789Sdim/// counts that are known to be a multiple of the vectorization factor. 137243789Sdim/// * It handles the code generation for reduction variables. 138243789Sdim/// * Scalarization (implementation using scalars) of un-vectorizable 139243789Sdim/// instructions. 140249423Sdim/// InnerLoopVectorizer does not perform any vectorization-legality 141243789Sdim/// checks, and relies on the caller to check for the different legality 142249423Sdim/// aspects. The InnerLoopVectorizer relies on the 143243789Sdim/// LoopVectorizationLegality class to provide information about the induction 144243789Sdim/// and reduction variables that were found to a given vectorization factor. 145249423Sdimclass InnerLoopVectorizer { 146243789Sdimpublic: 147249423Sdim InnerLoopVectorizer(Loop *OrigLoop, ScalarEvolution *SE, LoopInfo *LI, 148249423Sdim DominatorTree *DT, DataLayout *DL, 149249423Sdim const TargetLibraryInfo *TLI, unsigned VecWidth, 150249423Sdim unsigned UnrollFactor) 151249423Sdim : OrigLoop(OrigLoop), SE(SE), LI(LI), DT(DT), DL(DL), TLI(TLI), 152249423Sdim VF(VecWidth), UF(UnrollFactor), Builder(SE->getContext()), Induction(0), 153249423Sdim OldInduction(0), WidenMap(UnrollFactor) {} 154243789Sdim 155243789Sdim // Perform the actual loop widening (vectorization). 156243789Sdim void vectorize(LoopVectorizationLegality *Legal) { 157249423Sdim // Create a new empty loop. Unlink the old loop and connect the new one. 158243789Sdim createEmptyLoop(Legal); 159249423Sdim // Widen each instruction in the old loop to a new one in the new loop. 160249423Sdim // Use the Legality module to find the induction and reduction variables. 161243789Sdim vectorizeLoop(Legal); 162243789Sdim // Register the new loop and update the analysis passes. 163243789Sdim updateAnalysis(); 164249423Sdim } 165243789Sdim 166243789Sdimprivate: 167249423Sdim /// A small list of PHINodes. 168249423Sdim typedef SmallVector<PHINode*, 4> PhiVector; 169249423Sdim /// When we unroll loops we have multiple vector values for each scalar. 170249423Sdim /// This data structure holds the unrolled and vectorized values that 171249423Sdim /// originated from one scalar instruction. 172249423Sdim typedef SmallVector<Value*, 2> VectorParts; 173249423Sdim 174249423Sdim /// Add code that checks at runtime if the accessed arrays overlap. 175249423Sdim /// Returns the comparator value or NULL if no check is needed. 176249423Sdim Instruction *addRuntimeCheck(LoopVectorizationLegality *Legal, 177249423Sdim Instruction *Loc); 178243789Sdim /// Create an empty loop, based on the loop ranges of the old loop. 179243789Sdim void createEmptyLoop(LoopVectorizationLegality *Legal); 180243789Sdim /// Copy and widen the instructions from the old loop. 181243789Sdim void vectorizeLoop(LoopVectorizationLegality *Legal); 182249423Sdim 183249423Sdim /// A helper function that computes the predicate of the block BB, assuming 184249423Sdim /// that the header block of the loop is set to True. It returns the *entry* 185249423Sdim /// mask for the block BB. 186249423Sdim VectorParts createBlockInMask(BasicBlock *BB); 187249423Sdim /// A helper function that computes the predicate of the edge between SRC 188249423Sdim /// and DST. 189249423Sdim VectorParts createEdgeMask(BasicBlock *Src, BasicBlock *Dst); 190249423Sdim 191249423Sdim /// A helper function to vectorize a single BB within the innermost loop. 192249423Sdim void vectorizeBlockInLoop(LoopVectorizationLegality *Legal, BasicBlock *BB, 193249423Sdim PhiVector *PV); 194249423Sdim 195243789Sdim /// Insert the new loop to the loop hierarchy and pass manager 196243789Sdim /// and update the analysis passes. 197243789Sdim void updateAnalysis(); 198243789Sdim 199243789Sdim /// This instruction is un-vectorizable. Implement it as a sequence 200243789Sdim /// of scalars. 201243789Sdim void scalarizeInstruction(Instruction *Instr); 202243789Sdim 203249423Sdim /// Vectorize Load and Store instructions, 204249423Sdim void vectorizeMemoryInstruction(Instruction *Instr, 205249423Sdim LoopVectorizationLegality *Legal); 206249423Sdim 207243789Sdim /// Create a broadcast instruction. This method generates a broadcast 208243789Sdim /// instruction (shuffle) for loop invariant values and for the induction 209243789Sdim /// value. If this is the induction variable then we extend it to N, N+1, ... 210243789Sdim /// this is needed because each iteration in the loop corresponds to a SIMD 211243789Sdim /// element. 212243789Sdim Value *getBroadcastInstrs(Value *V); 213243789Sdim 214249423Sdim /// This function adds 0, 1, 2 ... to each vector element, starting at zero. 215249423Sdim /// If Negate is set then negative numbers are added e.g. (0, -1, -2, ...). 216249423Sdim /// The sequence starts at StartIndex. 217249423Sdim Value *getConsecutiveVector(Value* Val, unsigned StartIdx, bool Negate); 218243789Sdim 219243789Sdim /// When we go over instructions in the basic block we rely on previous 220243789Sdim /// values within the current basic block or on loop invariant values. 221243789Sdim /// When we widen (vectorize) values we place them in the map. If the values 222243789Sdim /// are not within the map, they have to be loop invariant, so we simply 223243789Sdim /// broadcast them into a vector. 224249423Sdim VectorParts &getVectorValue(Value *V); 225243789Sdim 226249423Sdim /// Generate a shuffle sequence that will reverse the vector Vec. 227249423Sdim Value *reverseVector(Value *Vec); 228243789Sdim 229249423Sdim /// This is a helper class that holds the vectorizer state. It maps scalar 230249423Sdim /// instructions to vector instructions. When the code is 'unrolled' then 231249423Sdim /// then a single scalar value is mapped to multiple vector parts. The parts 232249423Sdim /// are stored in the VectorPart type. 233249423Sdim struct ValueMap { 234249423Sdim /// C'tor. UnrollFactor controls the number of vectors ('parts') that 235249423Sdim /// are mapped. 236249423Sdim ValueMap(unsigned UnrollFactor) : UF(UnrollFactor) {} 237243789Sdim 238249423Sdim /// \return True if 'Key' is saved in the Value Map. 239249423Sdim bool has(Value *Key) const { return MapStorage.count(Key); } 240249423Sdim 241249423Sdim /// Initializes a new entry in the map. Sets all of the vector parts to the 242249423Sdim /// save value in 'Val'. 243249423Sdim /// \return A reference to a vector with splat values. 244249423Sdim VectorParts &splat(Value *Key, Value *Val) { 245249423Sdim VectorParts &Entry = MapStorage[Key]; 246249423Sdim Entry.assign(UF, Val); 247249423Sdim return Entry; 248249423Sdim } 249249423Sdim 250249423Sdim ///\return A reference to the value that is stored at 'Key'. 251249423Sdim VectorParts &get(Value *Key) { 252249423Sdim VectorParts &Entry = MapStorage[Key]; 253249423Sdim if (Entry.empty()) 254249423Sdim Entry.resize(UF); 255249423Sdim assert(Entry.size() == UF); 256249423Sdim return Entry; 257249423Sdim } 258249423Sdim 259249423Sdim private: 260249423Sdim /// The unroll factor. Each entry in the map stores this number of vector 261249423Sdim /// elements. 262249423Sdim unsigned UF; 263249423Sdim 264249423Sdim /// Map storage. We use std::map and not DenseMap because insertions to a 265249423Sdim /// dense map invalidates its iterators. 266249423Sdim std::map<Value *, VectorParts> MapStorage; 267249423Sdim }; 268249423Sdim 269243789Sdim /// The original loop. 270243789Sdim Loop *OrigLoop; 271249423Sdim /// Scev analysis to use. 272243789Sdim ScalarEvolution *SE; 273249423Sdim /// Loop Info. 274243789Sdim LoopInfo *LI; 275249423Sdim /// Dominator Tree. 276243789Sdim DominatorTree *DT; 277249423Sdim /// Data Layout. 278249423Sdim DataLayout *DL; 279249423Sdim /// Target Library Info. 280249423Sdim const TargetLibraryInfo *TLI; 281249423Sdim 282249423Sdim /// The vectorization SIMD factor to use. Each vector will have this many 283249423Sdim /// vector elements. 284243789Sdim unsigned VF; 285249423Sdim /// The vectorization unroll factor to use. Each scalar is vectorized to this 286249423Sdim /// many different vector instructions. 287249423Sdim unsigned UF; 288243789Sdim 289249423Sdim /// The builder that we use 290243789Sdim IRBuilder<> Builder; 291243789Sdim 292243789Sdim // --- Vectorization state --- 293243789Sdim 294243789Sdim /// The vector-loop preheader. 295243789Sdim BasicBlock *LoopVectorPreHeader; 296243789Sdim /// The scalar-loop preheader. 297243789Sdim BasicBlock *LoopScalarPreHeader; 298243789Sdim /// Middle Block between the vector and the scalar. 299243789Sdim BasicBlock *LoopMiddleBlock; 300243789Sdim ///The ExitBlock of the scalar loop. 301243789Sdim BasicBlock *LoopExitBlock; 302243789Sdim ///The vector loop body. 303243789Sdim BasicBlock *LoopVectorBody; 304243789Sdim ///The scalar loop body. 305243789Sdim BasicBlock *LoopScalarBody; 306249423Sdim /// A list of all bypass blocks. The first block is the entry of the loop. 307249423Sdim SmallVector<BasicBlock *, 4> LoopBypassBlocks; 308243789Sdim 309243789Sdim /// The new Induction variable which was added to the new block. 310243789Sdim PHINode *Induction; 311243789Sdim /// The induction variable of the old basic block. 312243789Sdim PHINode *OldInduction; 313249423Sdim /// Maps scalars to widened vectors. 314243789Sdim ValueMap WidenMap; 315243789Sdim}; 316243789Sdim 317243789Sdim/// LoopVectorizationLegality checks if it is legal to vectorize a loop, and 318243789Sdim/// to what vectorization factor. 319243789Sdim/// This class does not look at the profitability of vectorization, only the 320243789Sdim/// legality. This class has two main kinds of checks: 321243789Sdim/// * Memory checks - The code in canVectorizeMemory checks if vectorization 322243789Sdim/// will change the order of memory accesses in a way that will change the 323243789Sdim/// correctness of the program. 324249423Sdim/// * Scalars checks - The code in canVectorizeInstrs and canVectorizeMemory 325249423Sdim/// checks for a number of different conditions, such as the availability of a 326249423Sdim/// single induction variable, that all types are supported and vectorize-able, 327249423Sdim/// etc. This code reflects the capabilities of InnerLoopVectorizer. 328249423Sdim/// This class is also used by InnerLoopVectorizer for identifying 329243789Sdim/// induction variable and the different reduction variables. 330243789Sdimclass LoopVectorizationLegality { 331243789Sdimpublic: 332249423Sdim LoopVectorizationLegality(Loop *L, ScalarEvolution *SE, DataLayout *DL, 333249423Sdim DominatorTree *DT, TargetTransformInfo* TTI, 334249423Sdim AliasAnalysis *AA, TargetLibraryInfo *TLI) 335249423Sdim : TheLoop(L), SE(SE), DL(DL), DT(DT), TTI(TTI), AA(AA), TLI(TLI), 336249423Sdim Induction(0) {} 337243789Sdim 338249423Sdim /// This enum represents the kinds of reductions that we support. 339243789Sdim enum ReductionKind { 340249423Sdim RK_NoReduction, ///< Not a reduction. 341249423Sdim RK_IntegerAdd, ///< Sum of integers. 342249423Sdim RK_IntegerMult, ///< Product of integers. 343249423Sdim RK_IntegerOr, ///< Bitwise or logical OR of numbers. 344249423Sdim RK_IntegerAnd, ///< Bitwise or logical AND of numbers. 345249423Sdim RK_IntegerXor, ///< Bitwise or logical XOR of numbers. 346249423Sdim RK_FloatAdd, ///< Sum of floats. 347249423Sdim RK_FloatMult ///< Product of floats. 348243789Sdim }; 349243789Sdim 350249423Sdim /// This enum represents the kinds of inductions that we support. 351249423Sdim enum InductionKind { 352249423Sdim IK_NoInduction, ///< Not an induction variable. 353249423Sdim IK_IntInduction, ///< Integer induction variable. Step = 1. 354249423Sdim IK_ReverseIntInduction, ///< Reverse int induction variable. Step = -1. 355249423Sdim IK_PtrInduction, ///< Pointer induction var. Step = sizeof(elem). 356249423Sdim IK_ReversePtrInduction ///< Reverse ptr indvar. Step = - sizeof(elem). 357249423Sdim }; 358249423Sdim 359243789Sdim /// This POD struct holds information about reduction variables. 360243789Sdim struct ReductionDescriptor { 361249423Sdim ReductionDescriptor() : StartValue(0), LoopExitInstr(0), 362249423Sdim Kind(RK_NoReduction) {} 363243789Sdim 364249423Sdim ReductionDescriptor(Value *Start, Instruction *Exit, ReductionKind K) 365249423Sdim : StartValue(Start), LoopExitInstr(Exit), Kind(K) {} 366243789Sdim 367243789Sdim // The starting value of the reduction. 368243789Sdim // It does not have to be zero! 369243789Sdim Value *StartValue; 370243789Sdim // The instruction who's value is used outside the loop. 371243789Sdim Instruction *LoopExitInstr; 372243789Sdim // The kind of the reduction. 373243789Sdim ReductionKind Kind; 374243789Sdim }; 375243789Sdim 376243789Sdim // This POD struct holds information about the memory runtime legality 377243789Sdim // check that a group of pointers do not overlap. 378243789Sdim struct RuntimePointerCheck { 379249423Sdim RuntimePointerCheck() : Need(false) {} 380249423Sdim 381249423Sdim /// Reset the state of the pointer runtime information. 382249423Sdim void reset() { 383249423Sdim Need = false; 384249423Sdim Pointers.clear(); 385249423Sdim Starts.clear(); 386249423Sdim Ends.clear(); 387249423Sdim } 388249423Sdim 389249423Sdim /// Insert a pointer and calculate the start and end SCEVs. 390249423Sdim void insert(ScalarEvolution *SE, Loop *Lp, Value *Ptr); 391249423Sdim 392243789Sdim /// This flag indicates if we need to add the runtime check. 393243789Sdim bool Need; 394243789Sdim /// Holds the pointers that we need to check. 395243789Sdim SmallVector<Value*, 2> Pointers; 396249423Sdim /// Holds the pointer value at the beginning of the loop. 397249423Sdim SmallVector<const SCEV*, 2> Starts; 398249423Sdim /// Holds the pointer value at the end of the loop. 399249423Sdim SmallVector<const SCEV*, 2> Ends; 400243789Sdim }; 401243789Sdim 402249423Sdim /// A POD for saving information about induction variables. 403249423Sdim struct InductionInfo { 404249423Sdim InductionInfo(Value *Start, InductionKind K) : StartValue(Start), IK(K) {} 405249423Sdim InductionInfo() : StartValue(0), IK(IK_NoInduction) {} 406249423Sdim /// Start value. 407249423Sdim Value *StartValue; 408249423Sdim /// Induction kind. 409249423Sdim InductionKind IK; 410249423Sdim }; 411249423Sdim 412243789Sdim /// ReductionList contains the reduction descriptors for all 413243789Sdim /// of the reductions that were found in the loop. 414243789Sdim typedef DenseMap<PHINode*, ReductionDescriptor> ReductionList; 415243789Sdim 416249423Sdim /// InductionList saves induction variables and maps them to the 417249423Sdim /// induction descriptor. 418249423Sdim typedef MapVector<PHINode*, InductionInfo> InductionList; 419249423Sdim 420249423Sdim /// Alias(Multi)Map stores the values (GEPs or underlying objects and their 421249423Sdim /// respective Store/Load instruction(s) to calculate aliasing. 422249423Sdim typedef MapVector<Value*, Instruction* > AliasMap; 423249423Sdim typedef DenseMap<Value*, std::vector<Instruction*> > AliasMultiMap; 424249423Sdim 425243789Sdim /// Returns true if it is legal to vectorize this loop. 426243789Sdim /// This does not mean that it is profitable to vectorize this 427243789Sdim /// loop, only that it is legal to do so. 428243789Sdim bool canVectorize(); 429243789Sdim 430243789Sdim /// Returns the Induction variable. 431249423Sdim PHINode *getInduction() { return Induction; } 432243789Sdim 433243789Sdim /// Returns the reduction variables found in the loop. 434243789Sdim ReductionList *getReductionVars() { return &Reductions; } 435243789Sdim 436249423Sdim /// Returns the induction variables found in the loop. 437249423Sdim InductionList *getInductionVars() { return &Inductions; } 438249423Sdim 439249423Sdim /// Returns True if V is an induction variable in this loop. 440249423Sdim bool isInductionVariable(const Value *V); 441249423Sdim 442249423Sdim /// Return true if the block BB needs to be predicated in order for the loop 443249423Sdim /// to be vectorized. 444249423Sdim bool blockNeedsPredication(BasicBlock *BB); 445249423Sdim 446249423Sdim /// Check if this pointer is consecutive when vectorizing. This happens 447249423Sdim /// when the last index of the GEP is the induction variable, or that the 448249423Sdim /// pointer itself is an induction variable. 449243789Sdim /// This check allows us to vectorize A[idx] into a wide load/store. 450249423Sdim /// Returns: 451249423Sdim /// 0 - Stride is unknown or non consecutive. 452249423Sdim /// 1 - Address is consecutive. 453249423Sdim /// -1 - Address is consecutive, and decreasing. 454249423Sdim int isConsecutivePtr(Value *Ptr); 455243789Sdim 456243789Sdim /// Returns true if the value V is uniform within the loop. 457243789Sdim bool isUniform(Value *V); 458243789Sdim 459243789Sdim /// Returns true if this instruction will remain scalar after vectorization. 460249423Sdim bool isUniformAfterVectorization(Instruction* I) { return Uniforms.count(I); } 461243789Sdim 462243789Sdim /// Returns the information that we collected about runtime memory check. 463249423Sdim RuntimePointerCheck *getRuntimePointerCheck() { return &PtrRtCheck; } 464243789Sdimprivate: 465243789Sdim /// Check if a single basic block loop is vectorizable. 466243789Sdim /// At this point we know that this is a loop with a constant trip count 467243789Sdim /// and we only need to check individual instructions. 468249423Sdim bool canVectorizeInstrs(); 469243789Sdim 470243789Sdim /// When we vectorize loops we may change the order in which 471243789Sdim /// we read and write from memory. This method checks if it is 472243789Sdim /// legal to vectorize the code, considering only memory constrains. 473249423Sdim /// Returns true if the loop is vectorizable 474249423Sdim bool canVectorizeMemory(); 475243789Sdim 476249423Sdim /// Return true if we can vectorize this loop using the IF-conversion 477249423Sdim /// transformation. 478249423Sdim bool canVectorizeWithIfConvert(); 479249423Sdim 480249423Sdim /// Collect the variables that need to stay uniform after vectorization. 481249423Sdim void collectLoopUniforms(); 482249423Sdim 483249423Sdim /// Return true if all of the instructions in the block can be speculatively 484249423Sdim /// executed. 485249423Sdim bool blockCanBePredicated(BasicBlock *BB); 486249423Sdim 487243789Sdim /// Returns True, if 'Phi' is the kind of reduction variable for type 488243789Sdim /// 'Kind'. If this is a reduction variable, it adds it to ReductionList. 489243789Sdim bool AddReductionVar(PHINode *Phi, ReductionKind Kind); 490243789Sdim /// Returns true if the instruction I can be a reduction variable of type 491243789Sdim /// 'Kind'. 492243789Sdim bool isReductionInstr(Instruction *I, ReductionKind Kind); 493249423Sdim /// Returns the induction kind of Phi. This function may return NoInduction 494249423Sdim /// if the PHI is not an induction variable. 495249423Sdim InductionKind isInductionVariable(PHINode *Phi); 496243789Sdim /// Return true if can compute the address bounds of Ptr within the loop. 497243789Sdim bool hasComputableBounds(Value *Ptr); 498249423Sdim /// Return true if there is the chance of write reorder. 499249423Sdim bool hasPossibleGlobalWriteReorder(Value *Object, 500249423Sdim Instruction *Inst, 501249423Sdim AliasMultiMap &WriteObjects, 502249423Sdim unsigned MaxByteWidth); 503249423Sdim /// Return the AA location for a load or a store. 504249423Sdim AliasAnalysis::Location getLoadStoreLocation(Instruction *Inst); 505243789Sdim 506249423Sdim 507243789Sdim /// The loop that we evaluate. 508243789Sdim Loop *TheLoop; 509243789Sdim /// Scev analysis. 510243789Sdim ScalarEvolution *SE; 511243789Sdim /// DataLayout analysis. 512243789Sdim DataLayout *DL; 513249423Sdim /// Dominators. 514249423Sdim DominatorTree *DT; 515249423Sdim /// Target Info. 516249423Sdim TargetTransformInfo *TTI; 517249423Sdim /// Alias Analysis. 518249423Sdim AliasAnalysis *AA; 519249423Sdim /// Target Library Info. 520249423Sdim TargetLibraryInfo *TLI; 521243789Sdim 522243789Sdim // --- vectorization state --- // 523243789Sdim 524249423Sdim /// Holds the integer induction variable. This is the counter of the 525249423Sdim /// loop. 526243789Sdim PHINode *Induction; 527243789Sdim /// Holds the reduction variables. 528243789Sdim ReductionList Reductions; 529249423Sdim /// Holds all of the induction variables that we found in the loop. 530249423Sdim /// Notice that inductions don't need to start at zero and that induction 531249423Sdim /// variables can be pointers. 532249423Sdim InductionList Inductions; 533249423Sdim 534243789Sdim /// Allowed outside users. This holds the reduction 535243789Sdim /// vars which can be accessed from outside the loop. 536243789Sdim SmallPtrSet<Value*, 4> AllowedExit; 537243789Sdim /// This set holds the variables which are known to be uniform after 538243789Sdim /// vectorization. 539243789Sdim SmallPtrSet<Instruction*, 4> Uniforms; 540243789Sdim /// We need to check that all of the pointers in this list are disjoint 541243789Sdim /// at runtime. 542243789Sdim RuntimePointerCheck PtrRtCheck; 543243789Sdim}; 544243789Sdim 545243789Sdim/// LoopVectorizationCostModel - estimates the expected speedups due to 546243789Sdim/// vectorization. 547249423Sdim/// In many cases vectorization is not profitable. This can happen because of 548249423Sdim/// a number of reasons. In this class we mainly attempt to predict the 549249423Sdim/// expected speedup/slowdowns due to the supported instruction set. We use the 550249423Sdim/// TargetTransformInfo to query the different backends for the cost of 551249423Sdim/// different operations. 552243789Sdimclass LoopVectorizationCostModel { 553243789Sdimpublic: 554249423Sdim LoopVectorizationCostModel(Loop *L, ScalarEvolution *SE, LoopInfo *LI, 555249423Sdim LoopVectorizationLegality *Legal, 556249423Sdim const TargetTransformInfo &TTI, 557249423Sdim DataLayout *DL, const TargetLibraryInfo *TLI) 558249423Sdim : TheLoop(L), SE(SE), LI(LI), Legal(Legal), TTI(TTI), DL(DL), TLI(TLI) {} 559243789Sdim 560249423Sdim /// Information about vectorization costs 561249423Sdim struct VectorizationFactor { 562249423Sdim unsigned Width; // Vector width with best cost 563249423Sdim unsigned Cost; // Cost of the loop with that width 564249423Sdim }; 565249423Sdim /// \return The most profitable vectorization factor and the cost of that VF. 566249423Sdim /// This method checks every power of two up to VF. If UserVF is not ZERO 567249423Sdim /// then this vectorization factor will be selected if vectorization is 568249423Sdim /// possible. 569249423Sdim VectorizationFactor selectVectorizationFactor(bool OptForSize, 570249423Sdim unsigned UserVF); 571243789Sdim 572249423Sdim /// \return The size (in bits) of the widest type in the code that 573249423Sdim /// needs to be vectorized. We ignore values that remain scalar such as 574249423Sdim /// 64 bit loop indices. 575249423Sdim unsigned getWidestType(); 576249423Sdim 577249423Sdim /// \return The most profitable unroll factor. 578249423Sdim /// If UserUF is non-zero then this method finds the best unroll-factor 579249423Sdim /// based on register pressure and other parameters. 580249423Sdim /// VF and LoopCost are the selected vectorization factor and the cost of the 581249423Sdim /// selected VF. 582249423Sdim unsigned selectUnrollFactor(bool OptForSize, unsigned UserUF, unsigned VF, 583249423Sdim unsigned LoopCost); 584249423Sdim 585249423Sdim /// \brief A struct that represents some properties of the register usage 586249423Sdim /// of a loop. 587249423Sdim struct RegisterUsage { 588249423Sdim /// Holds the number of loop invariant values that are used in the loop. 589249423Sdim unsigned LoopInvariantRegs; 590249423Sdim /// Holds the maximum number of concurrent live intervals in the loop. 591249423Sdim unsigned MaxLocalUsers; 592249423Sdim /// Holds the number of instructions in the loop. 593249423Sdim unsigned NumInstructions; 594249423Sdim }; 595249423Sdim 596249423Sdim /// \return information about the register usage of the loop. 597249423Sdim RegisterUsage calculateRegisterUsage(); 598249423Sdim 599243789Sdimprivate: 600243789Sdim /// Returns the expected execution cost. The unit of the cost does 601243789Sdim /// not matter because we use the 'cost' units to compare different 602243789Sdim /// vector widths. The cost that is returned is *not* normalized by 603243789Sdim /// the factor width. 604243789Sdim unsigned expectedCost(unsigned VF); 605243789Sdim 606243789Sdim /// Returns the execution time cost of an instruction for a given vector 607243789Sdim /// width. Vector width of one means scalar. 608243789Sdim unsigned getInstructionCost(Instruction *I, unsigned VF); 609243789Sdim 610243789Sdim /// A helper function for converting Scalar types to vector types. 611243789Sdim /// If the incoming type is void, we return void. If the VF is 1, we return 612243789Sdim /// the scalar type. 613243789Sdim static Type* ToVectorTy(Type *Scalar, unsigned VF); 614243789Sdim 615249423Sdim /// Returns whether the instruction is a load or store and will be a emitted 616249423Sdim /// as a vector operation. 617249423Sdim bool isConsecutiveLoadOrStore(Instruction *I); 618249423Sdim 619243789Sdim /// The loop that we evaluate. 620243789Sdim Loop *TheLoop; 621243789Sdim /// Scev analysis. 622243789Sdim ScalarEvolution *SE; 623249423Sdim /// Loop Info analysis. 624249423Sdim LoopInfo *LI; 625243789Sdim /// Vectorization legality. 626243789Sdim LoopVectorizationLegality *Legal; 627243789Sdim /// Vector target information. 628249423Sdim const TargetTransformInfo &TTI; 629249423Sdim /// Target data layout information. 630249423Sdim DataLayout *DL; 631249423Sdim /// Target Library Info. 632249423Sdim const TargetLibraryInfo *TLI; 633243789Sdim}; 634243789Sdim 635249423Sdim/// The LoopVectorize Pass. 636243789Sdimstruct LoopVectorize : public LoopPass { 637249423Sdim /// Pass identification, replacement for typeid 638249423Sdim static char ID; 639243789Sdim 640249423Sdim explicit LoopVectorize() : LoopPass(ID) { 641243789Sdim initializeLoopVectorizePass(*PassRegistry::getPassRegistry()); 642243789Sdim } 643243789Sdim 644243789Sdim ScalarEvolution *SE; 645243789Sdim DataLayout *DL; 646243789Sdim LoopInfo *LI; 647243789Sdim TargetTransformInfo *TTI; 648243789Sdim DominatorTree *DT; 649249423Sdim AliasAnalysis *AA; 650249423Sdim TargetLibraryInfo *TLI; 651243789Sdim 652243789Sdim virtual bool runOnLoop(Loop *L, LPPassManager &LPM) { 653243789Sdim // We only vectorize innermost loops. 654243789Sdim if (!L->empty()) 655243789Sdim return false; 656243789Sdim 657243789Sdim SE = &getAnalysis<ScalarEvolution>(); 658243789Sdim DL = getAnalysisIfAvailable<DataLayout>(); 659243789Sdim LI = &getAnalysis<LoopInfo>(); 660249423Sdim TTI = &getAnalysis<TargetTransformInfo>(); 661243789Sdim DT = &getAnalysis<DominatorTree>(); 662249423Sdim AA = getAnalysisIfAvailable<AliasAnalysis>(); 663249423Sdim TLI = getAnalysisIfAvailable<TargetLibraryInfo>(); 664243789Sdim 665243789Sdim DEBUG(dbgs() << "LV: Checking a loop in \"" << 666243789Sdim L->getHeader()->getParent()->getName() << "\"\n"); 667243789Sdim 668243789Sdim // Check if it is legal to vectorize the loop. 669249423Sdim LoopVectorizationLegality LVL(L, SE, DL, DT, TTI, AA, TLI); 670243789Sdim if (!LVL.canVectorize()) { 671243789Sdim DEBUG(dbgs() << "LV: Not vectorizing.\n"); 672243789Sdim return false; 673243789Sdim } 674243789Sdim 675249423Sdim // Use the cost model. 676249423Sdim LoopVectorizationCostModel CM(L, SE, LI, &LVL, *TTI, DL, TLI); 677243789Sdim 678249423Sdim // Check the function attributes to find out if this function should be 679249423Sdim // optimized for size. 680249423Sdim Function *F = L->getHeader()->getParent(); 681249423Sdim Attribute::AttrKind SzAttr = Attribute::OptimizeForSize; 682249423Sdim Attribute::AttrKind FlAttr = Attribute::NoImplicitFloat; 683249423Sdim unsigned FnIndex = AttributeSet::FunctionIndex; 684249423Sdim bool OptForSize = F->getAttributes().hasAttribute(FnIndex, SzAttr); 685249423Sdim bool NoFloat = F->getAttributes().hasAttribute(FnIndex, FlAttr); 686243789Sdim 687249423Sdim if (NoFloat) { 688249423Sdim DEBUG(dbgs() << "LV: Can't vectorize when the NoImplicitFloat" 689249423Sdim "attribute is used.\n"); 690249423Sdim return false; 691243789Sdim } 692243789Sdim 693249423Sdim // Select the optimal vectorization factor. 694249423Sdim LoopVectorizationCostModel::VectorizationFactor VF; 695249423Sdim VF = CM.selectVectorizationFactor(OptForSize, VectorizationFactor); 696249423Sdim // Select the unroll factor. 697249423Sdim unsigned UF = CM.selectUnrollFactor(OptForSize, VectorizationUnroll, 698249423Sdim VF.Width, VF.Cost); 699243789Sdim 700249423Sdim if (VF.Width == 1) { 701249423Sdim DEBUG(dbgs() << "LV: Vectorization is possible but not beneficial.\n"); 702249423Sdim return false; 703249423Sdim } 704249423Sdim 705249423Sdim DEBUG(dbgs() << "LV: Found a vectorizable loop ("<< VF.Width << ") in "<< 706249423Sdim F->getParent()->getModuleIdentifier()<<"\n"); 707249423Sdim DEBUG(dbgs() << "LV: Unroll Factor is " << UF << "\n"); 708249423Sdim 709249423Sdim // If we decided that it is *legal* to vectorize the loop then do it. 710249423Sdim InnerLoopVectorizer LB(L, SE, LI, DT, DL, TLI, VF.Width, UF); 711243789Sdim LB.vectorize(&LVL); 712243789Sdim 713243789Sdim DEBUG(verifyFunction(*L->getHeader()->getParent())); 714243789Sdim return true; 715243789Sdim } 716243789Sdim 717243789Sdim virtual void getAnalysisUsage(AnalysisUsage &AU) const { 718243789Sdim LoopPass::getAnalysisUsage(AU); 719243789Sdim AU.addRequiredID(LoopSimplifyID); 720243789Sdim AU.addRequiredID(LCSSAID); 721249423Sdim AU.addRequired<DominatorTree>(); 722243789Sdim AU.addRequired<LoopInfo>(); 723243789Sdim AU.addRequired<ScalarEvolution>(); 724249423Sdim AU.addRequired<TargetTransformInfo>(); 725243789Sdim AU.addPreserved<LoopInfo>(); 726243789Sdim AU.addPreserved<DominatorTree>(); 727243789Sdim } 728243789Sdim 729243789Sdim}; 730243789Sdim 731249423Sdim} // end anonymous namespace 732249423Sdim 733249423Sdim//===----------------------------------------------------------------------===// 734249423Sdim// Implementation of LoopVectorizationLegality, InnerLoopVectorizer and 735249423Sdim// LoopVectorizationCostModel. 736249423Sdim//===----------------------------------------------------------------------===// 737249423Sdim 738249423Sdimvoid 739249423SdimLoopVectorizationLegality::RuntimePointerCheck::insert(ScalarEvolution *SE, 740249423Sdim Loop *Lp, Value *Ptr) { 741249423Sdim const SCEV *Sc = SE->getSCEV(Ptr); 742249423Sdim const SCEVAddRecExpr *AR = dyn_cast<SCEVAddRecExpr>(Sc); 743249423Sdim assert(AR && "Invalid addrec expression"); 744249423Sdim const SCEV *Ex = SE->getExitCount(Lp, Lp->getLoopLatch()); 745249423Sdim const SCEV *ScEnd = AR->evaluateAtIteration(Ex, *SE); 746249423Sdim Pointers.push_back(Ptr); 747249423Sdim Starts.push_back(AR->getStart()); 748249423Sdim Ends.push_back(ScEnd); 749249423Sdim} 750249423Sdim 751249423SdimValue *InnerLoopVectorizer::getBroadcastInstrs(Value *V) { 752249423Sdim // Save the current insertion location. 753249423Sdim Instruction *Loc = Builder.GetInsertPoint(); 754249423Sdim 755249423Sdim // We need to place the broadcast of invariant variables outside the loop. 756249423Sdim Instruction *Instr = dyn_cast<Instruction>(V); 757249423Sdim bool NewInstr = (Instr && Instr->getParent() == LoopVectorBody); 758249423Sdim bool Invariant = OrigLoop->isLoopInvariant(V) && !NewInstr; 759249423Sdim 760249423Sdim // Place the code for broadcasting invariant variables in the new preheader. 761249423Sdim if (Invariant) 762249423Sdim Builder.SetInsertPoint(LoopVectorPreHeader->getTerminator()); 763249423Sdim 764243789Sdim // Broadcast the scalar into all locations in the vector. 765249423Sdim Value *Shuf = Builder.CreateVectorSplat(VF, V, "broadcast"); 766249423Sdim 767249423Sdim // Restore the builder insertion point. 768249423Sdim if (Invariant) 769249423Sdim Builder.SetInsertPoint(Loc); 770249423Sdim 771243789Sdim return Shuf; 772243789Sdim} 773243789Sdim 774249423SdimValue *InnerLoopVectorizer::getConsecutiveVector(Value* Val, unsigned StartIdx, 775249423Sdim bool Negate) { 776243789Sdim assert(Val->getType()->isVectorTy() && "Must be a vector"); 777243789Sdim assert(Val->getType()->getScalarType()->isIntegerTy() && 778243789Sdim "Elem must be an integer"); 779243789Sdim // Create the types. 780243789Sdim Type *ITy = Val->getType()->getScalarType(); 781243789Sdim VectorType *Ty = cast<VectorType>(Val->getType()); 782249423Sdim int VLen = Ty->getNumElements(); 783243789Sdim SmallVector<Constant*, 8> Indices; 784243789Sdim 785243789Sdim // Create a vector of consecutive numbers from zero to VF. 786249423Sdim for (int i = 0; i < VLen; ++i) { 787249423Sdim int Idx = Negate ? (-i): i; 788249423Sdim Indices.push_back(ConstantInt::get(ITy, StartIdx + Idx)); 789249423Sdim } 790243789Sdim 791243789Sdim // Add the consecutive indices to the vector value. 792243789Sdim Constant *Cv = ConstantVector::get(Indices); 793243789Sdim assert(Cv->getType() == Val->getType() && "Invalid consecutive vec"); 794243789Sdim return Builder.CreateAdd(Val, Cv, "induction"); 795243789Sdim} 796243789Sdim 797249423Sdimint LoopVectorizationLegality::isConsecutivePtr(Value *Ptr) { 798249423Sdim assert(Ptr->getType()->isPointerTy() && "Unexpected non ptr"); 799249423Sdim // Make sure that the pointer does not point to structs. 800249423Sdim if (cast<PointerType>(Ptr->getType())->getElementType()->isAggregateType()) 801249423Sdim return 0; 802249423Sdim 803249423Sdim // If this value is a pointer induction variable we know it is consecutive. 804249423Sdim PHINode *Phi = dyn_cast_or_null<PHINode>(Ptr); 805249423Sdim if (Phi && Inductions.count(Phi)) { 806249423Sdim InductionInfo II = Inductions[Phi]; 807249423Sdim if (IK_PtrInduction == II.IK) 808249423Sdim return 1; 809249423Sdim else if (IK_ReversePtrInduction == II.IK) 810249423Sdim return -1; 811249423Sdim } 812249423Sdim 813243789Sdim GetElementPtrInst *Gep = dyn_cast_or_null<GetElementPtrInst>(Ptr); 814243789Sdim if (!Gep) 815249423Sdim return 0; 816243789Sdim 817243789Sdim unsigned NumOperands = Gep->getNumOperands(); 818243789Sdim Value *LastIndex = Gep->getOperand(NumOperands - 1); 819243789Sdim 820249423Sdim Value *GpPtr = Gep->getPointerOperand(); 821249423Sdim // If this GEP value is a consecutive pointer induction variable and all of 822249423Sdim // the indices are constant then we know it is consecutive. We can 823249423Sdim Phi = dyn_cast<PHINode>(GpPtr); 824249423Sdim if (Phi && Inductions.count(Phi)) { 825249423Sdim 826249423Sdim // Make sure that the pointer does not point to structs. 827249423Sdim PointerType *GepPtrType = cast<PointerType>(GpPtr->getType()); 828249423Sdim if (GepPtrType->getElementType()->isAggregateType()) 829249423Sdim return 0; 830249423Sdim 831249423Sdim // Make sure that all of the index operands are loop invariant. 832249423Sdim for (unsigned i = 1; i < NumOperands; ++i) 833249423Sdim if (!SE->isLoopInvariant(SE->getSCEV(Gep->getOperand(i)), TheLoop)) 834249423Sdim return 0; 835249423Sdim 836249423Sdim InductionInfo II = Inductions[Phi]; 837249423Sdim if (IK_PtrInduction == II.IK) 838249423Sdim return 1; 839249423Sdim else if (IK_ReversePtrInduction == II.IK) 840249423Sdim return -1; 841249423Sdim } 842249423Sdim 843243789Sdim // Check that all of the gep indices are uniform except for the last. 844243789Sdim for (unsigned i = 0; i < NumOperands - 1; ++i) 845243789Sdim if (!SE->isLoopInvariant(SE->getSCEV(Gep->getOperand(i)), TheLoop)) 846249423Sdim return 0; 847243789Sdim 848249423Sdim // We can emit wide load/stores only if the last index is the induction 849243789Sdim // variable. 850243789Sdim const SCEV *Last = SE->getSCEV(LastIndex); 851243789Sdim if (const SCEVAddRecExpr *AR = dyn_cast<SCEVAddRecExpr>(Last)) { 852243789Sdim const SCEV *Step = AR->getStepRecurrence(*SE); 853243789Sdim 854243789Sdim // The memory is consecutive because the last index is consecutive 855243789Sdim // and all other indices are loop invariant. 856243789Sdim if (Step->isOne()) 857249423Sdim return 1; 858249423Sdim if (Step->isAllOnesValue()) 859249423Sdim return -1; 860243789Sdim } 861243789Sdim 862249423Sdim return 0; 863243789Sdim} 864243789Sdim 865243789Sdimbool LoopVectorizationLegality::isUniform(Value *V) { 866243789Sdim return (SE->isLoopInvariant(SE->getSCEV(V), TheLoop)); 867243789Sdim} 868243789Sdim 869249423SdimInnerLoopVectorizer::VectorParts& 870249423SdimInnerLoopVectorizer::getVectorValue(Value *V) { 871249423Sdim assert(V != Induction && "The new induction variable should not be used."); 872243789Sdim assert(!V->getType()->isVectorTy() && "Can't widen a vector"); 873243789Sdim 874249423Sdim // If we have this scalar in the map, return it. 875249423Sdim if (WidenMap.has(V)) 876249423Sdim return WidenMap.get(V); 877249423Sdim 878249423Sdim // If this scalar is unknown, assume that it is a constant or that it is 879249423Sdim // loop invariant. Broadcast V and save the value for future uses. 880243789Sdim Value *B = getBroadcastInstrs(V); 881249423Sdim return WidenMap.splat(V, B); 882243789Sdim} 883243789Sdim 884249423SdimValue *InnerLoopVectorizer::reverseVector(Value *Vec) { 885249423Sdim assert(Vec->getType()->isVectorTy() && "Invalid type"); 886249423Sdim SmallVector<Constant*, 8> ShuffleMask; 887243789Sdim for (unsigned i = 0; i < VF; ++i) 888249423Sdim ShuffleMask.push_back(Builder.getInt32(VF - i - 1)); 889243789Sdim 890249423Sdim return Builder.CreateShuffleVector(Vec, UndefValue::get(Vec->getType()), 891249423Sdim ConstantVector::get(ShuffleMask), 892249423Sdim "reverse"); 893243789Sdim} 894243789Sdim 895249423Sdim 896249423Sdimvoid InnerLoopVectorizer::vectorizeMemoryInstruction(Instruction *Instr, 897249423Sdim LoopVectorizationLegality *Legal) { 898249423Sdim // Attempt to issue a wide load. 899249423Sdim LoadInst *LI = dyn_cast<LoadInst>(Instr); 900249423Sdim StoreInst *SI = dyn_cast<StoreInst>(Instr); 901249423Sdim 902249423Sdim assert((LI || SI) && "Invalid Load/Store instruction"); 903249423Sdim 904249423Sdim Type *ScalarDataTy = LI ? LI->getType() : SI->getValueOperand()->getType(); 905249423Sdim Type *DataTy = VectorType::get(ScalarDataTy, VF); 906249423Sdim Value *Ptr = LI ? LI->getPointerOperand() : SI->getPointerOperand(); 907249423Sdim unsigned Alignment = LI ? LI->getAlignment() : SI->getAlignment(); 908249423Sdim 909249423Sdim // If the pointer is loop invariant or if it is non consecutive, 910249423Sdim // scalarize the load. 911249423Sdim int Stride = Legal->isConsecutivePtr(Ptr); 912249423Sdim bool Reverse = Stride < 0; 913249423Sdim bool UniformLoad = LI && Legal->isUniform(Ptr); 914249423Sdim if (Stride == 0 || UniformLoad) 915249423Sdim return scalarizeInstruction(Instr); 916249423Sdim 917249423Sdim Constant *Zero = Builder.getInt32(0); 918249423Sdim VectorParts &Entry = WidenMap.get(Instr); 919249423Sdim 920249423Sdim // Handle consecutive loads/stores. 921249423Sdim GetElementPtrInst *Gep = dyn_cast<GetElementPtrInst>(Ptr); 922249423Sdim if (Gep && Legal->isInductionVariable(Gep->getPointerOperand())) { 923249423Sdim Value *PtrOperand = Gep->getPointerOperand(); 924249423Sdim Value *FirstBasePtr = getVectorValue(PtrOperand)[0]; 925249423Sdim FirstBasePtr = Builder.CreateExtractElement(FirstBasePtr, Zero); 926249423Sdim 927249423Sdim // Create the new GEP with the new induction variable. 928249423Sdim GetElementPtrInst *Gep2 = cast<GetElementPtrInst>(Gep->clone()); 929249423Sdim Gep2->setOperand(0, FirstBasePtr); 930249423Sdim Gep2->setName("gep.indvar.base"); 931249423Sdim Ptr = Builder.Insert(Gep2); 932249423Sdim } else if (Gep) { 933249423Sdim assert(SE->isLoopInvariant(SE->getSCEV(Gep->getPointerOperand()), 934249423Sdim OrigLoop) && "Base ptr must be invariant"); 935249423Sdim 936249423Sdim // The last index does not have to be the induction. It can be 937249423Sdim // consecutive and be a function of the index. For example A[I+1]; 938249423Sdim unsigned NumOperands = Gep->getNumOperands(); 939249423Sdim 940249423Sdim Value *LastGepOperand = Gep->getOperand(NumOperands - 1); 941249423Sdim VectorParts &GEPParts = getVectorValue(LastGepOperand); 942249423Sdim Value *LastIndex = GEPParts[0]; 943249423Sdim LastIndex = Builder.CreateExtractElement(LastIndex, Zero); 944249423Sdim 945249423Sdim // Create the new GEP with the new induction variable. 946249423Sdim GetElementPtrInst *Gep2 = cast<GetElementPtrInst>(Gep->clone()); 947249423Sdim Gep2->setOperand(NumOperands - 1, LastIndex); 948249423Sdim Gep2->setName("gep.indvar.idx"); 949249423Sdim Ptr = Builder.Insert(Gep2); 950249423Sdim } else { 951249423Sdim // Use the induction element ptr. 952249423Sdim assert(isa<PHINode>(Ptr) && "Invalid induction ptr"); 953249423Sdim VectorParts &PtrVal = getVectorValue(Ptr); 954249423Sdim Ptr = Builder.CreateExtractElement(PtrVal[0], Zero); 955249423Sdim } 956249423Sdim 957249423Sdim // Handle Stores: 958249423Sdim if (SI) { 959249423Sdim assert(!Legal->isUniform(SI->getPointerOperand()) && 960249423Sdim "We do not allow storing to uniform addresses"); 961249423Sdim 962249423Sdim VectorParts &StoredVal = getVectorValue(SI->getValueOperand()); 963249423Sdim for (unsigned Part = 0; Part < UF; ++Part) { 964249423Sdim // Calculate the pointer for the specific unroll-part. 965249423Sdim Value *PartPtr = Builder.CreateGEP(Ptr, Builder.getInt32(Part * VF)); 966249423Sdim 967249423Sdim if (Reverse) { 968249423Sdim // If we store to reverse consecutive memory locations then we need 969249423Sdim // to reverse the order of elements in the stored value. 970249423Sdim StoredVal[Part] = reverseVector(StoredVal[Part]); 971249423Sdim // If the address is consecutive but reversed, then the 972249423Sdim // wide store needs to start at the last vector element. 973249423Sdim PartPtr = Builder.CreateGEP(Ptr, Builder.getInt32(-Part * VF)); 974249423Sdim PartPtr = Builder.CreateGEP(PartPtr, Builder.getInt32(1 - VF)); 975249423Sdim } 976249423Sdim 977249423Sdim Value *VecPtr = Builder.CreateBitCast(PartPtr, DataTy->getPointerTo()); 978249423Sdim Builder.CreateStore(StoredVal[Part], VecPtr)->setAlignment(Alignment); 979249423Sdim } 980249423Sdim } 981249423Sdim 982249423Sdim for (unsigned Part = 0; Part < UF; ++Part) { 983249423Sdim // Calculate the pointer for the specific unroll-part. 984249423Sdim Value *PartPtr = Builder.CreateGEP(Ptr, Builder.getInt32(Part * VF)); 985249423Sdim 986249423Sdim if (Reverse) { 987249423Sdim // If the address is consecutive but reversed, then the 988249423Sdim // wide store needs to start at the last vector element. 989249423Sdim PartPtr = Builder.CreateGEP(Ptr, Builder.getInt32(-Part * VF)); 990249423Sdim PartPtr = Builder.CreateGEP(PartPtr, Builder.getInt32(1 - VF)); 991249423Sdim } 992249423Sdim 993249423Sdim Value *VecPtr = Builder.CreateBitCast(PartPtr, DataTy->getPointerTo()); 994249423Sdim Value *LI = Builder.CreateLoad(VecPtr, "wide.load"); 995249423Sdim cast<LoadInst>(LI)->setAlignment(Alignment); 996249423Sdim Entry[Part] = Reverse ? reverseVector(LI) : LI; 997249423Sdim } 998249423Sdim} 999249423Sdim 1000249423Sdimvoid InnerLoopVectorizer::scalarizeInstruction(Instruction *Instr) { 1001243789Sdim assert(!Instr->getType()->isAggregateType() && "Can't handle vectors"); 1002243789Sdim // Holds vector parameters or scalars, in case of uniform vals. 1003249423Sdim SmallVector<VectorParts, 4> Params; 1004243789Sdim 1005243789Sdim // Find all of the vectorized parameters. 1006243789Sdim for (unsigned op = 0, e = Instr->getNumOperands(); op != e; ++op) { 1007243789Sdim Value *SrcOp = Instr->getOperand(op); 1008243789Sdim 1009243789Sdim // If we are accessing the old induction variable, use the new one. 1010243789Sdim if (SrcOp == OldInduction) { 1011249423Sdim Params.push_back(getVectorValue(SrcOp)); 1012243789Sdim continue; 1013243789Sdim } 1014243789Sdim 1015243789Sdim // Try using previously calculated values. 1016243789Sdim Instruction *SrcInst = dyn_cast<Instruction>(SrcOp); 1017243789Sdim 1018243789Sdim // If the src is an instruction that appeared earlier in the basic block 1019243789Sdim // then it should already be vectorized. 1020249423Sdim if (SrcInst && OrigLoop->contains(SrcInst)) { 1021249423Sdim assert(WidenMap.has(SrcInst) && "Source operand is unavailable"); 1022243789Sdim // The parameter is a vector value from earlier. 1023249423Sdim Params.push_back(WidenMap.get(SrcInst)); 1024243789Sdim } else { 1025243789Sdim // The parameter is a scalar from outside the loop. Maybe even a constant. 1026249423Sdim VectorParts Scalars; 1027249423Sdim Scalars.append(UF, SrcOp); 1028249423Sdim Params.push_back(Scalars); 1029243789Sdim } 1030243789Sdim } 1031243789Sdim 1032243789Sdim assert(Params.size() == Instr->getNumOperands() && 1033243789Sdim "Invalid number of operands"); 1034243789Sdim 1035243789Sdim // Does this instruction return a value ? 1036243789Sdim bool IsVoidRetTy = Instr->getType()->isVoidTy(); 1037243789Sdim 1038249423Sdim Value *UndefVec = IsVoidRetTy ? 0 : 1039249423Sdim UndefValue::get(VectorType::get(Instr->getType(), VF)); 1040249423Sdim // Create a new entry in the WidenMap and initialize it to Undef or Null. 1041249423Sdim VectorParts &VecResults = WidenMap.splat(Instr, UndefVec); 1042243789Sdim 1043243789Sdim // For each scalar that we create: 1044249423Sdim for (unsigned Width = 0; Width < VF; ++Width) { 1045249423Sdim // For each vector unroll 'part': 1046249423Sdim for (unsigned Part = 0; Part < UF; ++Part) { 1047249423Sdim Instruction *Cloned = Instr->clone(); 1048249423Sdim if (!IsVoidRetTy) 1049249423Sdim Cloned->setName(Instr->getName() + ".cloned"); 1050249423Sdim // Replace the operands of the cloned instrucions with extracted scalars. 1051249423Sdim for (unsigned op = 0, e = Instr->getNumOperands(); op != e; ++op) { 1052249423Sdim Value *Op = Params[op][Part]; 1053249423Sdim // Param is a vector. Need to extract the right lane. 1054249423Sdim if (Op->getType()->isVectorTy()) 1055249423Sdim Op = Builder.CreateExtractElement(Op, Builder.getInt32(Width)); 1056249423Sdim Cloned->setOperand(op, Op); 1057249423Sdim } 1058249423Sdim 1059249423Sdim // Place the cloned scalar in the new loop. 1060249423Sdim Builder.Insert(Cloned); 1061249423Sdim 1062249423Sdim // If the original scalar returns a value we need to place it in a vector 1063249423Sdim // so that future users will be able to use it. 1064249423Sdim if (!IsVoidRetTy) 1065249423Sdim VecResults[Part] = Builder.CreateInsertElement(VecResults[Part], Cloned, 1066249423Sdim Builder.getInt32(Width)); 1067243789Sdim } 1068249423Sdim } 1069249423Sdim} 1070243789Sdim 1071249423SdimInstruction * 1072249423SdimInnerLoopVectorizer::addRuntimeCheck(LoopVectorizationLegality *Legal, 1073249423Sdim Instruction *Loc) { 1074249423Sdim LoopVectorizationLegality::RuntimePointerCheck *PtrRtCheck = 1075249423Sdim Legal->getRuntimePointerCheck(); 1076243789Sdim 1077249423Sdim if (!PtrRtCheck->Need) 1078249423Sdim return NULL; 1079249423Sdim 1080249423Sdim Instruction *MemoryRuntimeCheck = 0; 1081249423Sdim unsigned NumPointers = PtrRtCheck->Pointers.size(); 1082249423Sdim SmallVector<Value* , 2> Starts; 1083249423Sdim SmallVector<Value* , 2> Ends; 1084249423Sdim 1085249423Sdim SCEVExpander Exp(*SE, "induction"); 1086249423Sdim 1087249423Sdim // Use this type for pointer arithmetic. 1088249423Sdim Type* PtrArithTy = Type::getInt8PtrTy(Loc->getContext(), 0); 1089249423Sdim 1090249423Sdim for (unsigned i = 0; i < NumPointers; ++i) { 1091249423Sdim Value *Ptr = PtrRtCheck->Pointers[i]; 1092249423Sdim const SCEV *Sc = SE->getSCEV(Ptr); 1093249423Sdim 1094249423Sdim if (SE->isLoopInvariant(Sc, OrigLoop)) { 1095249423Sdim DEBUG(dbgs() << "LV: Adding RT check for a loop invariant ptr:" << 1096249423Sdim *Ptr <<"\n"); 1097249423Sdim Starts.push_back(Ptr); 1098249423Sdim Ends.push_back(Ptr); 1099249423Sdim } else { 1100249423Sdim DEBUG(dbgs() << "LV: Adding RT check for range:" << *Ptr <<"\n"); 1101249423Sdim 1102249423Sdim Value *Start = Exp.expandCodeFor(PtrRtCheck->Starts[i], PtrArithTy, Loc); 1103249423Sdim Value *End = Exp.expandCodeFor(PtrRtCheck->Ends[i], PtrArithTy, Loc); 1104249423Sdim Starts.push_back(Start); 1105249423Sdim Ends.push_back(End); 1106249423Sdim } 1107243789Sdim } 1108243789Sdim 1109249423Sdim IRBuilder<> ChkBuilder(Loc); 1110249423Sdim 1111249423Sdim for (unsigned i = 0; i < NumPointers; ++i) { 1112249423Sdim for (unsigned j = i+1; j < NumPointers; ++j) { 1113249423Sdim Value *Start0 = ChkBuilder.CreateBitCast(Starts[i], PtrArithTy, "bc"); 1114249423Sdim Value *Start1 = ChkBuilder.CreateBitCast(Starts[j], PtrArithTy, "bc"); 1115249423Sdim Value *End0 = ChkBuilder.CreateBitCast(Ends[i], PtrArithTy, "bc"); 1116249423Sdim Value *End1 = ChkBuilder.CreateBitCast(Ends[j], PtrArithTy, "bc"); 1117249423Sdim 1118249423Sdim Value *Cmp0 = ChkBuilder.CreateICmpULE(Start0, End1, "bound0"); 1119249423Sdim Value *Cmp1 = ChkBuilder.CreateICmpULE(Start1, End0, "bound1"); 1120249423Sdim Value *IsConflict = ChkBuilder.CreateAnd(Cmp0, Cmp1, "found.conflict"); 1121249423Sdim if (MemoryRuntimeCheck) 1122249423Sdim IsConflict = ChkBuilder.CreateOr(MemoryRuntimeCheck, IsConflict, 1123249423Sdim "conflict.rdx"); 1124249423Sdim 1125249423Sdim MemoryRuntimeCheck = cast<Instruction>(IsConflict); 1126249423Sdim } 1127249423Sdim } 1128249423Sdim 1129249423Sdim return MemoryRuntimeCheck; 1130243789Sdim} 1131243789Sdim 1132243789Sdimvoid 1133249423SdimInnerLoopVectorizer::createEmptyLoop(LoopVectorizationLegality *Legal) { 1134243789Sdim /* 1135243789Sdim In this function we generate a new loop. The new loop will contain 1136243789Sdim the vectorized instructions while the old loop will continue to run the 1137243789Sdim scalar remainder. 1138243789Sdim 1139249423Sdim [ ] <-- vector loop bypass (may consist of multiple blocks). 1140249423Sdim / | 1141249423Sdim / v 1142249423Sdim | [ ] <-- vector pre header. 1143249423Sdim | | 1144249423Sdim | v 1145249423Sdim | [ ] \ 1146249423Sdim | [ ]_| <-- vector loop. 1147249423Sdim | | 1148249423Sdim \ v 1149249423Sdim >[ ] <--- middle-block. 1150249423Sdim / | 1151249423Sdim / v 1152249423Sdim | [ ] <--- new preheader. 1153249423Sdim | | 1154249423Sdim | v 1155249423Sdim | [ ] \ 1156249423Sdim | [ ]_| <-- old scalar loop to handle remainder. 1157249423Sdim \ | 1158249423Sdim \ v 1159249423Sdim >[ ] <-- exit block. 1160243789Sdim ... 1161243789Sdim */ 1162243789Sdim 1163249423Sdim BasicBlock *OldBasicBlock = OrigLoop->getHeader(); 1164249423Sdim BasicBlock *BypassBlock = OrigLoop->getLoopPreheader(); 1165249423Sdim BasicBlock *ExitBlock = OrigLoop->getExitBlock(); 1166249423Sdim assert(ExitBlock && "Must have an exit block"); 1167249423Sdim 1168249423Sdim // Mark the old scalar loop with metadata that tells us not to vectorize this 1169249423Sdim // loop again if we run into it. 1170249423Sdim MDNode *MD = MDNode::get(OldBasicBlock->getContext(), ArrayRef<Value*>()); 1171249423Sdim OldBasicBlock->getTerminator()->setMetadata(AlreadyVectorizedMDName, MD); 1172249423Sdim 1173249423Sdim // Some loops have a single integer induction variable, while other loops 1174249423Sdim // don't. One example is c++ iterators that often have multiple pointer 1175249423Sdim // induction variables. In the code below we also support a case where we 1176249423Sdim // don't have a single induction variable. 1177243789Sdim OldInduction = Legal->getInduction(); 1178249423Sdim Type *IdxTy = OldInduction ? OldInduction->getType() : 1179249423Sdim DL->getIntPtrType(SE->getContext()); 1180243789Sdim 1181243789Sdim // Find the loop boundaries. 1182249423Sdim const SCEV *ExitCount = SE->getExitCount(OrigLoop, OrigLoop->getLoopLatch()); 1183243789Sdim assert(ExitCount != SE->getCouldNotCompute() && "Invalid loop count"); 1184243789Sdim 1185243789Sdim // Get the total trip count from the count by adding 1. 1186243789Sdim ExitCount = SE->getAddExpr(ExitCount, 1187243789Sdim SE->getConstant(ExitCount->getType(), 1)); 1188243789Sdim 1189249423Sdim // Expand the trip count and place the new instructions in the preheader. 1190249423Sdim // Notice that the pre-header does not change, only the loop body. 1191249423Sdim SCEVExpander Exp(*SE, "induction"); 1192243789Sdim 1193249423Sdim // Count holds the overall loop count (N). 1194249423Sdim Value *Count = Exp.expandCodeFor(ExitCount, ExitCount->getType(), 1195249423Sdim BypassBlock->getTerminator()); 1196243789Sdim 1197249423Sdim // The loop index does not have to start at Zero. Find the original start 1198249423Sdim // value from the induction PHI node. If we don't have an induction variable 1199249423Sdim // then we know that it starts at zero. 1200249423Sdim Value *StartIdx = OldInduction ? 1201249423Sdim OldInduction->getIncomingValueForBlock(BypassBlock): 1202249423Sdim ConstantInt::get(IdxTy, 0); 1203249423Sdim 1204243789Sdim assert(BypassBlock && "Invalid loop structure"); 1205249423Sdim LoopBypassBlocks.push_back(BypassBlock); 1206243789Sdim 1207249423Sdim // Split the single block loop into the two loop structure described above. 1208243789Sdim BasicBlock *VectorPH = 1209249423Sdim BypassBlock->splitBasicBlock(BypassBlock->getTerminator(), "vector.ph"); 1210249423Sdim BasicBlock *VecBody = 1211249423Sdim VectorPH->splitBasicBlock(VectorPH->getTerminator(), "vector.body"); 1212249423Sdim BasicBlock *MiddleBlock = 1213249423Sdim VecBody->splitBasicBlock(VecBody->getTerminator(), "middle.block"); 1214243789Sdim BasicBlock *ScalarPH = 1215249423Sdim MiddleBlock->splitBasicBlock(MiddleBlock->getTerminator(), "scalar.ph"); 1216243789Sdim 1217243789Sdim // Use this IR builder to create the loop instructions (Phi, Br, Cmp) 1218243789Sdim // inside the loop. 1219243789Sdim Builder.SetInsertPoint(VecBody->getFirstInsertionPt()); 1220243789Sdim 1221243789Sdim // Generate the induction variable. 1222243789Sdim Induction = Builder.CreatePHI(IdxTy, 2, "index"); 1223249423Sdim // The loop step is equal to the vectorization factor (num of SIMD elements) 1224249423Sdim // times the unroll factor (num of SIMD instructions). 1225249423Sdim Constant *Step = ConstantInt::get(IdxTy, VF * UF); 1226243789Sdim 1227249423Sdim // This is the IR builder that we use to add all of the logic for bypassing 1228249423Sdim // the new vector loop. 1229249423Sdim IRBuilder<> BypassBuilder(BypassBlock->getTerminator()); 1230243789Sdim 1231249423Sdim // We may need to extend the index in case there is a type mismatch. 1232249423Sdim // We know that the count starts at zero and does not overflow. 1233249423Sdim if (Count->getType() != IdxTy) { 1234249423Sdim // The exit count can be of pointer type. Convert it to the correct 1235249423Sdim // integer type. 1236249423Sdim if (ExitCount->getType()->isPointerTy()) 1237249423Sdim Count = BypassBuilder.CreatePointerCast(Count, IdxTy, "ptrcnt.to.int"); 1238249423Sdim else 1239249423Sdim Count = BypassBuilder.CreateZExtOrTrunc(Count, IdxTy, "cnt.cast"); 1240249423Sdim } 1241243789Sdim 1242243789Sdim // Add the start index to the loop count to get the new end index. 1243249423Sdim Value *IdxEnd = BypassBuilder.CreateAdd(Count, StartIdx, "end.idx"); 1244243789Sdim 1245243789Sdim // Now we need to generate the expression for N - (N % VF), which is 1246243789Sdim // the part that the vectorized body will execute. 1247249423Sdim Value *R = BypassBuilder.CreateURem(Count, Step, "n.mod.vf"); 1248249423Sdim Value *CountRoundDown = BypassBuilder.CreateSub(Count, R, "n.vec"); 1249249423Sdim Value *IdxEndRoundDown = BypassBuilder.CreateAdd(CountRoundDown, StartIdx, 1250249423Sdim "end.idx.rnd.down"); 1251243789Sdim 1252249423Sdim // Now, compare the new count to zero. If it is zero skip the vector loop and 1253249423Sdim // jump to the scalar loop. 1254249423Sdim Value *Cmp = BypassBuilder.CreateICmpEQ(IdxEndRoundDown, StartIdx, 1255249423Sdim "cmp.zero"); 1256243789Sdim 1257249423Sdim BasicBlock *LastBypassBlock = BypassBlock; 1258243789Sdim 1259249423Sdim // Generate the code that checks in runtime if arrays overlap. We put the 1260249423Sdim // checks into a separate block to make the more common case of few elements 1261249423Sdim // faster. 1262249423Sdim Instruction *MemRuntimeCheck = addRuntimeCheck(Legal, 1263249423Sdim BypassBlock->getTerminator()); 1264249423Sdim if (MemRuntimeCheck) { 1265249423Sdim // Create a new block containing the memory check. 1266249423Sdim BasicBlock *CheckBlock = BypassBlock->splitBasicBlock(MemRuntimeCheck, 1267249423Sdim "vector.memcheck"); 1268249423Sdim LoopBypassBlocks.push_back(CheckBlock); 1269243789Sdim 1270249423Sdim // Replace the branch into the memory check block with a conditional branch 1271249423Sdim // for the "few elements case". 1272249423Sdim Instruction *OldTerm = BypassBlock->getTerminator(); 1273249423Sdim BranchInst::Create(MiddleBlock, CheckBlock, Cmp, OldTerm); 1274249423Sdim OldTerm->eraseFromParent(); 1275243789Sdim 1276249423Sdim Cmp = MemRuntimeCheck; 1277249423Sdim LastBypassBlock = CheckBlock; 1278249423Sdim } 1279243789Sdim 1280249423Sdim LastBypassBlock->getTerminator()->eraseFromParent(); 1281249423Sdim BranchInst::Create(MiddleBlock, VectorPH, Cmp, 1282249423Sdim LastBypassBlock); 1283249423Sdim 1284249423Sdim // We are going to resume the execution of the scalar loop. 1285249423Sdim // Go over all of the induction variables that we found and fix the 1286249423Sdim // PHIs that are left in the scalar version of the loop. 1287249423Sdim // The starting values of PHI nodes depend on the counter of the last 1288249423Sdim // iteration in the vectorized loop. 1289249423Sdim // If we come from a bypass edge then we need to start from the original 1290249423Sdim // start value. 1291249423Sdim 1292249423Sdim // This variable saves the new starting index for the scalar loop. 1293249423Sdim PHINode *ResumeIndex = 0; 1294249423Sdim LoopVectorizationLegality::InductionList::iterator I, E; 1295249423Sdim LoopVectorizationLegality::InductionList *List = Legal->getInductionVars(); 1296249423Sdim for (I = List->begin(), E = List->end(); I != E; ++I) { 1297249423Sdim PHINode *OrigPhi = I->first; 1298249423Sdim LoopVectorizationLegality::InductionInfo II = I->second; 1299249423Sdim PHINode *ResumeVal = PHINode::Create(OrigPhi->getType(), 2, "resume.val", 1300249423Sdim MiddleBlock->getTerminator()); 1301249423Sdim Value *EndValue = 0; 1302249423Sdim switch (II.IK) { 1303249423Sdim case LoopVectorizationLegality::IK_NoInduction: 1304249423Sdim llvm_unreachable("Unknown induction"); 1305249423Sdim case LoopVectorizationLegality::IK_IntInduction: { 1306249423Sdim // Handle the integer induction counter: 1307249423Sdim assert(OrigPhi->getType()->isIntegerTy() && "Invalid type"); 1308249423Sdim assert(OrigPhi == OldInduction && "Unknown integer PHI"); 1309249423Sdim // We know what the end value is. 1310249423Sdim EndValue = IdxEndRoundDown; 1311249423Sdim // We also know which PHI node holds it. 1312249423Sdim ResumeIndex = ResumeVal; 1313249423Sdim break; 1314243789Sdim } 1315249423Sdim case LoopVectorizationLegality::IK_ReverseIntInduction: { 1316249423Sdim // Convert the CountRoundDown variable to the PHI size. 1317249423Sdim unsigned CRDSize = CountRoundDown->getType()->getScalarSizeInBits(); 1318249423Sdim unsigned IISize = II.StartValue->getType()->getScalarSizeInBits(); 1319249423Sdim Value *CRD = CountRoundDown; 1320249423Sdim if (CRDSize > IISize) 1321249423Sdim CRD = CastInst::Create(Instruction::Trunc, CountRoundDown, 1322249423Sdim II.StartValue->getType(), "tr.crd", 1323249423Sdim LoopBypassBlocks.back()->getTerminator()); 1324249423Sdim else if (CRDSize < IISize) 1325249423Sdim CRD = CastInst::Create(Instruction::SExt, CountRoundDown, 1326249423Sdim II.StartValue->getType(), 1327249423Sdim "sext.crd", 1328249423Sdim LoopBypassBlocks.back()->getTerminator()); 1329249423Sdim // Handle reverse integer induction counter: 1330249423Sdim EndValue = 1331249423Sdim BinaryOperator::CreateSub(II.StartValue, CRD, "rev.ind.end", 1332249423Sdim LoopBypassBlocks.back()->getTerminator()); 1333249423Sdim break; 1334249423Sdim } 1335249423Sdim case LoopVectorizationLegality::IK_PtrInduction: { 1336249423Sdim // For pointer induction variables, calculate the offset using 1337249423Sdim // the end index. 1338249423Sdim EndValue = 1339249423Sdim GetElementPtrInst::Create(II.StartValue, CountRoundDown, "ptr.ind.end", 1340249423Sdim LoopBypassBlocks.back()->getTerminator()); 1341249423Sdim break; 1342249423Sdim } 1343249423Sdim case LoopVectorizationLegality::IK_ReversePtrInduction: { 1344249423Sdim // The value at the end of the loop for the reverse pointer is calculated 1345249423Sdim // by creating a GEP with a negative index starting from the start value. 1346249423Sdim Value *Zero = ConstantInt::get(CountRoundDown->getType(), 0); 1347249423Sdim Value *NegIdx = BinaryOperator::CreateSub(Zero, CountRoundDown, 1348249423Sdim "rev.ind.end", 1349249423Sdim LoopBypassBlocks.back()->getTerminator()); 1350249423Sdim EndValue = GetElementPtrInst::Create(II.StartValue, NegIdx, 1351249423Sdim "rev.ptr.ind.end", 1352249423Sdim LoopBypassBlocks.back()->getTerminator()); 1353249423Sdim break; 1354249423Sdim } 1355249423Sdim }// end of case 1356243789Sdim 1357249423Sdim // The new PHI merges the original incoming value, in case of a bypass, 1358249423Sdim // or the value at the end of the vectorized loop. 1359249423Sdim for (unsigned I = 0, E = LoopBypassBlocks.size(); I != E; ++I) 1360249423Sdim ResumeVal->addIncoming(II.StartValue, LoopBypassBlocks[I]); 1361249423Sdim ResumeVal->addIncoming(EndValue, VecBody); 1362249423Sdim 1363249423Sdim // Fix the scalar body counter (PHI node). 1364249423Sdim unsigned BlockIdx = OrigPhi->getBasicBlockIndex(ScalarPH); 1365249423Sdim OrigPhi->setIncomingValue(BlockIdx, ResumeVal); 1366243789Sdim } 1367243789Sdim 1368249423Sdim // If we are generating a new induction variable then we also need to 1369249423Sdim // generate the code that calculates the exit value. This value is not 1370249423Sdim // simply the end of the counter because we may skip the vectorized body 1371249423Sdim // in case of a runtime check. 1372249423Sdim if (!OldInduction){ 1373249423Sdim assert(!ResumeIndex && "Unexpected resume value found"); 1374249423Sdim ResumeIndex = PHINode::Create(IdxTy, 2, "new.indc.resume.val", 1375249423Sdim MiddleBlock->getTerminator()); 1376249423Sdim for (unsigned I = 0, E = LoopBypassBlocks.size(); I != E; ++I) 1377249423Sdim ResumeIndex->addIncoming(StartIdx, LoopBypassBlocks[I]); 1378249423Sdim ResumeIndex->addIncoming(IdxEndRoundDown, VecBody); 1379249423Sdim } 1380243789Sdim 1381249423Sdim // Make sure that we found the index where scalar loop needs to continue. 1382249423Sdim assert(ResumeIndex && ResumeIndex->getType()->isIntegerTy() && 1383249423Sdim "Invalid resume Index"); 1384243789Sdim 1385243789Sdim // Add a check in the middle block to see if we have completed 1386243789Sdim // all of the iterations in the first vector loop. 1387243789Sdim // If (N - N%VF) == N, then we *don't* need to run the remainder. 1388243789Sdim Value *CmpN = CmpInst::Create(Instruction::ICmp, CmpInst::ICMP_EQ, IdxEnd, 1389243789Sdim ResumeIndex, "cmp.n", 1390243789Sdim MiddleBlock->getTerminator()); 1391243789Sdim 1392243789Sdim BranchInst::Create(ExitBlock, ScalarPH, CmpN, MiddleBlock->getTerminator()); 1393243789Sdim // Remove the old terminator. 1394243789Sdim MiddleBlock->getTerminator()->eraseFromParent(); 1395243789Sdim 1396243789Sdim // Create i+1 and fill the PHINode. 1397243789Sdim Value *NextIdx = Builder.CreateAdd(Induction, Step, "index.next"); 1398243789Sdim Induction->addIncoming(StartIdx, VectorPH); 1399243789Sdim Induction->addIncoming(NextIdx, VecBody); 1400243789Sdim // Create the compare. 1401243789Sdim Value *ICmp = Builder.CreateICmpEQ(NextIdx, IdxEndRoundDown); 1402243789Sdim Builder.CreateCondBr(ICmp, MiddleBlock, VecBody); 1403243789Sdim 1404243789Sdim // Now we have two terminators. Remove the old one from the block. 1405243789Sdim VecBody->getTerminator()->eraseFromParent(); 1406243789Sdim 1407243789Sdim // Get ready to start creating new instructions into the vectorized body. 1408243789Sdim Builder.SetInsertPoint(VecBody->getFirstInsertionPt()); 1409243789Sdim 1410249423Sdim // Create and register the new vector loop. 1411243789Sdim Loop* Lp = new Loop(); 1412249423Sdim Loop *ParentLoop = OrigLoop->getParentLoop(); 1413243789Sdim 1414249423Sdim // Insert the new loop into the loop nest and register the new basic blocks. 1415243789Sdim if (ParentLoop) { 1416249423Sdim ParentLoop->addChildLoop(Lp); 1417249423Sdim for (unsigned I = 1, E = LoopBypassBlocks.size(); I != E; ++I) 1418249423Sdim ParentLoop->addBasicBlockToLoop(LoopBypassBlocks[I], LI->getBase()); 1419243789Sdim ParentLoop->addBasicBlockToLoop(ScalarPH, LI->getBase()); 1420243789Sdim ParentLoop->addBasicBlockToLoop(VectorPH, LI->getBase()); 1421243789Sdim ParentLoop->addBasicBlockToLoop(MiddleBlock, LI->getBase()); 1422249423Sdim } else { 1423249423Sdim LI->addTopLevelLoop(Lp); 1424243789Sdim } 1425243789Sdim 1426249423Sdim Lp->addBasicBlockToLoop(VecBody, LI->getBase()); 1427249423Sdim 1428243789Sdim // Save the state. 1429243789Sdim LoopVectorPreHeader = VectorPH; 1430243789Sdim LoopScalarPreHeader = ScalarPH; 1431243789Sdim LoopMiddleBlock = MiddleBlock; 1432243789Sdim LoopExitBlock = ExitBlock; 1433243789Sdim LoopVectorBody = VecBody; 1434243789Sdim LoopScalarBody = OldBasicBlock; 1435243789Sdim} 1436243789Sdim 1437243789Sdim/// This function returns the identity element (or neutral element) for 1438243789Sdim/// the operation K. 1439249423Sdimstatic Constant* 1440249423SdimgetReductionIdentity(LoopVectorizationLegality::ReductionKind K, Type *Tp) { 1441243789Sdim switch (K) { 1442249423Sdim case LoopVectorizationLegality:: RK_IntegerXor: 1443249423Sdim case LoopVectorizationLegality:: RK_IntegerAdd: 1444249423Sdim case LoopVectorizationLegality:: RK_IntegerOr: 1445243789Sdim // Adding, Xoring, Oring zero to a number does not change it. 1446249423Sdim return ConstantInt::get(Tp, 0); 1447249423Sdim case LoopVectorizationLegality:: RK_IntegerMult: 1448243789Sdim // Multiplying a number by 1 does not change it. 1449249423Sdim return ConstantInt::get(Tp, 1); 1450249423Sdim case LoopVectorizationLegality:: RK_IntegerAnd: 1451243789Sdim // AND-ing a number with an all-1 value does not change it. 1452249423Sdim return ConstantInt::get(Tp, -1, true); 1453249423Sdim case LoopVectorizationLegality:: RK_FloatMult: 1454249423Sdim // Multiplying a number by 1 does not change it. 1455249423Sdim return ConstantFP::get(Tp, 1.0L); 1456249423Sdim case LoopVectorizationLegality:: RK_FloatAdd: 1457249423Sdim // Adding zero to a number does not change it. 1458249423Sdim return ConstantFP::get(Tp, 0.0L); 1459243789Sdim default: 1460243789Sdim llvm_unreachable("Unknown reduction kind"); 1461243789Sdim } 1462243789Sdim} 1463243789Sdim 1464249423Sdimstatic Intrinsic::ID 1465249423SdimgetIntrinsicIDForCall(CallInst *CI, const TargetLibraryInfo *TLI) { 1466249423Sdim // If we have an intrinsic call, check if it is trivially vectorizable. 1467249423Sdim if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(CI)) { 1468249423Sdim switch (II->getIntrinsicID()) { 1469249423Sdim case Intrinsic::sqrt: 1470249423Sdim case Intrinsic::sin: 1471249423Sdim case Intrinsic::cos: 1472249423Sdim case Intrinsic::exp: 1473249423Sdim case Intrinsic::exp2: 1474249423Sdim case Intrinsic::log: 1475249423Sdim case Intrinsic::log10: 1476249423Sdim case Intrinsic::log2: 1477249423Sdim case Intrinsic::fabs: 1478249423Sdim case Intrinsic::floor: 1479249423Sdim case Intrinsic::ceil: 1480249423Sdim case Intrinsic::trunc: 1481249423Sdim case Intrinsic::rint: 1482249423Sdim case Intrinsic::nearbyint: 1483249423Sdim case Intrinsic::pow: 1484249423Sdim case Intrinsic::fma: 1485249423Sdim case Intrinsic::fmuladd: 1486249423Sdim return II->getIntrinsicID(); 1487249423Sdim default: 1488249423Sdim return Intrinsic::not_intrinsic; 1489249423Sdim } 1490249423Sdim } 1491249423Sdim 1492249423Sdim if (!TLI) 1493249423Sdim return Intrinsic::not_intrinsic; 1494249423Sdim 1495249423Sdim LibFunc::Func Func; 1496249423Sdim Function *F = CI->getCalledFunction(); 1497249423Sdim // We're going to make assumptions on the semantics of the functions, check 1498249423Sdim // that the target knows that it's available in this environment. 1499249423Sdim if (!F || !TLI->getLibFunc(F->getName(), Func)) 1500249423Sdim return Intrinsic::not_intrinsic; 1501249423Sdim 1502249423Sdim // Otherwise check if we have a call to a function that can be turned into a 1503249423Sdim // vector intrinsic. 1504249423Sdim switch (Func) { 1505249423Sdim default: 1506249423Sdim break; 1507249423Sdim case LibFunc::sin: 1508249423Sdim case LibFunc::sinf: 1509249423Sdim case LibFunc::sinl: 1510249423Sdim return Intrinsic::sin; 1511249423Sdim case LibFunc::cos: 1512249423Sdim case LibFunc::cosf: 1513249423Sdim case LibFunc::cosl: 1514249423Sdim return Intrinsic::cos; 1515249423Sdim case LibFunc::exp: 1516249423Sdim case LibFunc::expf: 1517249423Sdim case LibFunc::expl: 1518249423Sdim return Intrinsic::exp; 1519249423Sdim case LibFunc::exp2: 1520249423Sdim case LibFunc::exp2f: 1521249423Sdim case LibFunc::exp2l: 1522249423Sdim return Intrinsic::exp2; 1523249423Sdim case LibFunc::log: 1524249423Sdim case LibFunc::logf: 1525249423Sdim case LibFunc::logl: 1526249423Sdim return Intrinsic::log; 1527249423Sdim case LibFunc::log10: 1528249423Sdim case LibFunc::log10f: 1529249423Sdim case LibFunc::log10l: 1530249423Sdim return Intrinsic::log10; 1531249423Sdim case LibFunc::log2: 1532249423Sdim case LibFunc::log2f: 1533249423Sdim case LibFunc::log2l: 1534249423Sdim return Intrinsic::log2; 1535249423Sdim case LibFunc::fabs: 1536249423Sdim case LibFunc::fabsf: 1537249423Sdim case LibFunc::fabsl: 1538249423Sdim return Intrinsic::fabs; 1539249423Sdim case LibFunc::floor: 1540249423Sdim case LibFunc::floorf: 1541249423Sdim case LibFunc::floorl: 1542249423Sdim return Intrinsic::floor; 1543249423Sdim case LibFunc::ceil: 1544249423Sdim case LibFunc::ceilf: 1545249423Sdim case LibFunc::ceill: 1546249423Sdim return Intrinsic::ceil; 1547249423Sdim case LibFunc::trunc: 1548249423Sdim case LibFunc::truncf: 1549249423Sdim case LibFunc::truncl: 1550249423Sdim return Intrinsic::trunc; 1551249423Sdim case LibFunc::rint: 1552249423Sdim case LibFunc::rintf: 1553249423Sdim case LibFunc::rintl: 1554249423Sdim return Intrinsic::rint; 1555249423Sdim case LibFunc::nearbyint: 1556249423Sdim case LibFunc::nearbyintf: 1557249423Sdim case LibFunc::nearbyintl: 1558249423Sdim return Intrinsic::nearbyint; 1559249423Sdim case LibFunc::pow: 1560249423Sdim case LibFunc::powf: 1561249423Sdim case LibFunc::powl: 1562249423Sdim return Intrinsic::pow; 1563249423Sdim } 1564249423Sdim 1565249423Sdim return Intrinsic::not_intrinsic; 1566249423Sdim} 1567249423Sdim 1568249423Sdim/// This function translates the reduction kind to an LLVM binary operator. 1569249423Sdimstatic Instruction::BinaryOps 1570249423SdimgetReductionBinOp(LoopVectorizationLegality::ReductionKind Kind) { 1571249423Sdim switch (Kind) { 1572249423Sdim case LoopVectorizationLegality::RK_IntegerAdd: 1573249423Sdim return Instruction::Add; 1574249423Sdim case LoopVectorizationLegality::RK_IntegerMult: 1575249423Sdim return Instruction::Mul; 1576249423Sdim case LoopVectorizationLegality::RK_IntegerOr: 1577249423Sdim return Instruction::Or; 1578249423Sdim case LoopVectorizationLegality::RK_IntegerAnd: 1579249423Sdim return Instruction::And; 1580249423Sdim case LoopVectorizationLegality::RK_IntegerXor: 1581249423Sdim return Instruction::Xor; 1582249423Sdim case LoopVectorizationLegality::RK_FloatMult: 1583249423Sdim return Instruction::FMul; 1584249423Sdim case LoopVectorizationLegality::RK_FloatAdd: 1585249423Sdim return Instruction::FAdd; 1586249423Sdim default: 1587249423Sdim llvm_unreachable("Unknown reduction operation"); 1588249423Sdim } 1589249423Sdim} 1590249423Sdim 1591243789Sdimvoid 1592249423SdimInnerLoopVectorizer::vectorizeLoop(LoopVectorizationLegality *Legal) { 1593243789Sdim //===------------------------------------------------===// 1594243789Sdim // 1595243789Sdim // Notice: any optimization or new instruction that go 1596243789Sdim // into the code below should be also be implemented in 1597243789Sdim // the cost-model. 1598243789Sdim // 1599243789Sdim //===------------------------------------------------===// 1600249423Sdim Constant *Zero = Builder.getInt32(0); 1601243789Sdim 1602243789Sdim // In order to support reduction variables we need to be able to vectorize 1603243789Sdim // Phi nodes. Phi nodes have cycles, so we need to vectorize them in two 1604249423Sdim // stages. First, we create a new vector PHI node with no incoming edges. 1605243789Sdim // We use this value when we vectorize all of the instructions that use the 1606243789Sdim // PHI. Next, after all of the instructions in the block are complete we 1607243789Sdim // add the new incoming edges to the PHI. At this point all of the 1608243789Sdim // instructions in the basic block are vectorized, so we can use them to 1609243789Sdim // construct the PHI. 1610249423Sdim PhiVector RdxPHIsToFix; 1611243789Sdim 1612249423Sdim // Scan the loop in a topological order to ensure that defs are vectorized 1613249423Sdim // before users. 1614249423Sdim LoopBlocksDFS DFS(OrigLoop); 1615249423Sdim DFS.perform(LI); 1616243789Sdim 1617249423Sdim // Vectorize all of the blocks in the original loop. 1618249423Sdim for (LoopBlocksDFS::RPOIterator bb = DFS.beginRPO(), 1619249423Sdim be = DFS.endRPO(); bb != be; ++bb) 1620249423Sdim vectorizeBlockInLoop(Legal, *bb, &RdxPHIsToFix); 1621243789Sdim 1622249423Sdim // At this point every instruction in the original loop is widened to 1623243789Sdim // a vector form. We are almost done. Now, we need to fix the PHI nodes 1624243789Sdim // that we vectorized. The PHI nodes are currently empty because we did 1625243789Sdim // not want to introduce cycles. Notice that the remaining PHI nodes 1626243789Sdim // that we need to fix are reduction variables. 1627243789Sdim 1628243789Sdim // Create the 'reduced' values for each of the induction vars. 1629243789Sdim // The reduced values are the vector values that we scalarize and combine 1630243789Sdim // after the loop is finished. 1631249423Sdim for (PhiVector::iterator it = RdxPHIsToFix.begin(), e = RdxPHIsToFix.end(); 1632243789Sdim it != e; ++it) { 1633243789Sdim PHINode *RdxPhi = *it; 1634243789Sdim assert(RdxPhi && "Unable to recover vectorized PHI"); 1635243789Sdim 1636243789Sdim // Find the reduction variable descriptor. 1637243789Sdim assert(Legal->getReductionVars()->count(RdxPhi) && 1638243789Sdim "Unable to find the reduction variable"); 1639243789Sdim LoopVectorizationLegality::ReductionDescriptor RdxDesc = 1640249423Sdim (*Legal->getReductionVars())[RdxPhi]; 1641243789Sdim 1642243789Sdim // We need to generate a reduction vector from the incoming scalar. 1643243789Sdim // To do so, we need to generate the 'identity' vector and overide 1644243789Sdim // one of the elements with the incoming scalar reduction. We need 1645243789Sdim // to do it in the vector-loop preheader. 1646249423Sdim Builder.SetInsertPoint(LoopBypassBlocks.front()->getTerminator()); 1647243789Sdim 1648243789Sdim // This is the vector-clone of the value that leaves the loop. 1649249423Sdim VectorParts &VectorExit = getVectorValue(RdxDesc.LoopExitInstr); 1650249423Sdim Type *VecTy = VectorExit[0]->getType(); 1651243789Sdim 1652243789Sdim // Find the reduction identity variable. Zero for addition, or, xor, 1653243789Sdim // one for multiplication, -1 for And. 1654249423Sdim Constant *Iden = getReductionIdentity(RdxDesc.Kind, VecTy->getScalarType()); 1655249423Sdim Constant *Identity = ConstantVector::getSplat(VF, Iden); 1656243789Sdim 1657243789Sdim // This vector is the Identity vector where the first element is the 1658243789Sdim // incoming scalar reduction. 1659243789Sdim Value *VectorStart = Builder.CreateInsertElement(Identity, 1660249423Sdim RdxDesc.StartValue, Zero); 1661243789Sdim 1662243789Sdim // Fix the vector-loop phi. 1663243789Sdim // We created the induction variable so we know that the 1664243789Sdim // preheader is the first entry. 1665243789Sdim BasicBlock *VecPreheader = Induction->getIncomingBlock(0); 1666243789Sdim 1667243789Sdim // Reductions do not have to start at zero. They can start with 1668243789Sdim // any loop invariant values. 1669249423Sdim VectorParts &VecRdxPhi = WidenMap.get(RdxPhi); 1670249423Sdim BasicBlock *Latch = OrigLoop->getLoopLatch(); 1671249423Sdim Value *LoopVal = RdxPhi->getIncomingValueForBlock(Latch); 1672249423Sdim VectorParts &Val = getVectorValue(LoopVal); 1673249423Sdim for (unsigned part = 0; part < UF; ++part) { 1674249423Sdim // Make sure to add the reduction stat value only to the 1675249423Sdim // first unroll part. 1676249423Sdim Value *StartVal = (part == 0) ? VectorStart : Identity; 1677249423Sdim cast<PHINode>(VecRdxPhi[part])->addIncoming(StartVal, VecPreheader); 1678249423Sdim cast<PHINode>(VecRdxPhi[part])->addIncoming(Val[part], LoopVectorBody); 1679249423Sdim } 1680243789Sdim 1681243789Sdim // Before each round, move the insertion point right between 1682243789Sdim // the PHIs and the values we are going to write. 1683243789Sdim // This allows us to write both PHINodes and the extractelement 1684243789Sdim // instructions. 1685243789Sdim Builder.SetInsertPoint(LoopMiddleBlock->getFirstInsertionPt()); 1686243789Sdim 1687249423Sdim VectorParts RdxParts; 1688249423Sdim for (unsigned part = 0; part < UF; ++part) { 1689249423Sdim // This PHINode contains the vectorized reduction variable, or 1690249423Sdim // the initial value vector, if we bypass the vector loop. 1691249423Sdim VectorParts &RdxExitVal = getVectorValue(RdxDesc.LoopExitInstr); 1692249423Sdim PHINode *NewPhi = Builder.CreatePHI(VecTy, 2, "rdx.vec.exit.phi"); 1693249423Sdim Value *StartVal = (part == 0) ? VectorStart : Identity; 1694249423Sdim for (unsigned I = 0, E = LoopBypassBlocks.size(); I != E; ++I) 1695249423Sdim NewPhi->addIncoming(StartVal, LoopBypassBlocks[I]); 1696249423Sdim NewPhi->addIncoming(RdxExitVal[part], LoopVectorBody); 1697249423Sdim RdxParts.push_back(NewPhi); 1698249423Sdim } 1699243789Sdim 1700249423Sdim // Reduce all of the unrolled parts into a single vector. 1701249423Sdim Value *ReducedPartRdx = RdxParts[0]; 1702249423Sdim for (unsigned part = 1; part < UF; ++part) { 1703249423Sdim Instruction::BinaryOps Op = getReductionBinOp(RdxDesc.Kind); 1704249423Sdim ReducedPartRdx = Builder.CreateBinOp(Op, RdxParts[part], ReducedPartRdx, 1705249423Sdim "bin.rdx"); 1706243789Sdim } 1707243789Sdim 1708249423Sdim // VF is a power of 2 so we can emit the reduction using log2(VF) shuffles 1709249423Sdim // and vector ops, reducing the set of values being computed by half each 1710249423Sdim // round. 1711249423Sdim assert(isPowerOf2_32(VF) && 1712249423Sdim "Reduction emission only supported for pow2 vectors!"); 1713249423Sdim Value *TmpVec = ReducedPartRdx; 1714249423Sdim SmallVector<Constant*, 32> ShuffleMask(VF, 0); 1715249423Sdim for (unsigned i = VF; i != 1; i >>= 1) { 1716249423Sdim // Move the upper half of the vector to the lower half. 1717249423Sdim for (unsigned j = 0; j != i/2; ++j) 1718249423Sdim ShuffleMask[j] = Builder.getInt32(i/2 + j); 1719249423Sdim 1720249423Sdim // Fill the rest of the mask with undef. 1721249423Sdim std::fill(&ShuffleMask[i/2], ShuffleMask.end(), 1722249423Sdim UndefValue::get(Builder.getInt32Ty())); 1723249423Sdim 1724249423Sdim Value *Shuf = 1725249423Sdim Builder.CreateShuffleVector(TmpVec, 1726249423Sdim UndefValue::get(TmpVec->getType()), 1727249423Sdim ConstantVector::get(ShuffleMask), 1728249423Sdim "rdx.shuf"); 1729249423Sdim 1730249423Sdim Instruction::BinaryOps Op = getReductionBinOp(RdxDesc.Kind); 1731249423Sdim TmpVec = Builder.CreateBinOp(Op, TmpVec, Shuf, "bin.rdx"); 1732249423Sdim } 1733249423Sdim 1734249423Sdim // The result is in the first element of the vector. 1735249423Sdim Value *Scalar0 = Builder.CreateExtractElement(TmpVec, Builder.getInt32(0)); 1736249423Sdim 1737243789Sdim // Now, we need to fix the users of the reduction variable 1738243789Sdim // inside and outside of the scalar remainder loop. 1739243789Sdim // We know that the loop is in LCSSA form. We need to update the 1740243789Sdim // PHI nodes in the exit blocks. 1741243789Sdim for (BasicBlock::iterator LEI = LoopExitBlock->begin(), 1742243789Sdim LEE = LoopExitBlock->end(); LEI != LEE; ++LEI) { 1743243789Sdim PHINode *LCSSAPhi = dyn_cast<PHINode>(LEI); 1744243789Sdim if (!LCSSAPhi) continue; 1745243789Sdim 1746243789Sdim // All PHINodes need to have a single entry edge, or two if 1747243789Sdim // we already fixed them. 1748243789Sdim assert(LCSSAPhi->getNumIncomingValues() < 3 && "Invalid LCSSA PHI"); 1749243789Sdim 1750243789Sdim // We found our reduction value exit-PHI. Update it with the 1751243789Sdim // incoming bypass edge. 1752243789Sdim if (LCSSAPhi->getIncomingValue(0) == RdxDesc.LoopExitInstr) { 1753243789Sdim // Add an edge coming from the bypass. 1754243789Sdim LCSSAPhi->addIncoming(Scalar0, LoopMiddleBlock); 1755243789Sdim break; 1756243789Sdim } 1757243789Sdim }// end of the LCSSA phi scan. 1758243789Sdim 1759243789Sdim // Fix the scalar loop reduction variable with the incoming reduction sum 1760243789Sdim // from the vector body and from the backedge value. 1761249423Sdim int IncomingEdgeBlockIdx = 1762249423Sdim (RdxPhi)->getBasicBlockIndex(OrigLoop->getLoopLatch()); 1763249423Sdim assert(IncomingEdgeBlockIdx >= 0 && "Invalid block index"); 1764249423Sdim // Pick the other block. 1765249423Sdim int SelfEdgeBlockIdx = (IncomingEdgeBlockIdx ? 0 : 1); 1766243789Sdim (RdxPhi)->setIncomingValue(SelfEdgeBlockIdx, Scalar0); 1767243789Sdim (RdxPhi)->setIncomingValue(IncomingEdgeBlockIdx, RdxDesc.LoopExitInstr); 1768243789Sdim }// end of for each redux variable. 1769249423Sdim 1770249423Sdim // The Loop exit block may have single value PHI nodes where the incoming 1771249423Sdim // value is 'undef'. While vectorizing we only handled real values that 1772249423Sdim // were defined inside the loop. Here we handle the 'undef case'. 1773249423Sdim // See PR14725. 1774249423Sdim for (BasicBlock::iterator LEI = LoopExitBlock->begin(), 1775249423Sdim LEE = LoopExitBlock->end(); LEI != LEE; ++LEI) { 1776249423Sdim PHINode *LCSSAPhi = dyn_cast<PHINode>(LEI); 1777249423Sdim if (!LCSSAPhi) continue; 1778249423Sdim if (LCSSAPhi->getNumIncomingValues() == 1) 1779249423Sdim LCSSAPhi->addIncoming(UndefValue::get(LCSSAPhi->getType()), 1780249423Sdim LoopMiddleBlock); 1781249423Sdim } 1782243789Sdim} 1783243789Sdim 1784249423SdimInnerLoopVectorizer::VectorParts 1785249423SdimInnerLoopVectorizer::createEdgeMask(BasicBlock *Src, BasicBlock *Dst) { 1786249423Sdim assert(std::find(pred_begin(Dst), pred_end(Dst), Src) != pred_end(Dst) && 1787249423Sdim "Invalid edge"); 1788249423Sdim 1789249423Sdim VectorParts SrcMask = createBlockInMask(Src); 1790249423Sdim 1791249423Sdim // The terminator has to be a branch inst! 1792249423Sdim BranchInst *BI = dyn_cast<BranchInst>(Src->getTerminator()); 1793249423Sdim assert(BI && "Unexpected terminator found"); 1794249423Sdim 1795249423Sdim if (BI->isConditional()) { 1796249423Sdim VectorParts EdgeMask = getVectorValue(BI->getCondition()); 1797249423Sdim 1798249423Sdim if (BI->getSuccessor(0) != Dst) 1799249423Sdim for (unsigned part = 0; part < UF; ++part) 1800249423Sdim EdgeMask[part] = Builder.CreateNot(EdgeMask[part]); 1801249423Sdim 1802249423Sdim for (unsigned part = 0; part < UF; ++part) 1803249423Sdim EdgeMask[part] = Builder.CreateAnd(EdgeMask[part], SrcMask[part]); 1804249423Sdim return EdgeMask; 1805249423Sdim } 1806249423Sdim 1807249423Sdim return SrcMask; 1808249423Sdim} 1809249423Sdim 1810249423SdimInnerLoopVectorizer::VectorParts 1811249423SdimInnerLoopVectorizer::createBlockInMask(BasicBlock *BB) { 1812249423Sdim assert(OrigLoop->contains(BB) && "Block is not a part of a loop"); 1813249423Sdim 1814249423Sdim // Loop incoming mask is all-one. 1815249423Sdim if (OrigLoop->getHeader() == BB) { 1816249423Sdim Value *C = ConstantInt::get(IntegerType::getInt1Ty(BB->getContext()), 1); 1817249423Sdim return getVectorValue(C); 1818249423Sdim } 1819249423Sdim 1820249423Sdim // This is the block mask. We OR all incoming edges, and with zero. 1821249423Sdim Value *Zero = ConstantInt::get(IntegerType::getInt1Ty(BB->getContext()), 0); 1822249423Sdim VectorParts BlockMask = getVectorValue(Zero); 1823249423Sdim 1824249423Sdim // For each pred: 1825249423Sdim for (pred_iterator it = pred_begin(BB), e = pred_end(BB); it != e; ++it) { 1826249423Sdim VectorParts EM = createEdgeMask(*it, BB); 1827249423Sdim for (unsigned part = 0; part < UF; ++part) 1828249423Sdim BlockMask[part] = Builder.CreateOr(BlockMask[part], EM[part]); 1829249423Sdim } 1830249423Sdim 1831249423Sdim return BlockMask; 1832249423Sdim} 1833249423Sdim 1834249423Sdimvoid 1835249423SdimInnerLoopVectorizer::vectorizeBlockInLoop(LoopVectorizationLegality *Legal, 1836249423Sdim BasicBlock *BB, PhiVector *PV) { 1837249423Sdim // For each instruction in the old loop. 1838249423Sdim for (BasicBlock::iterator it = BB->begin(), e = BB->end(); it != e; ++it) { 1839249423Sdim VectorParts &Entry = WidenMap.get(it); 1840249423Sdim switch (it->getOpcode()) { 1841249423Sdim case Instruction::Br: 1842249423Sdim // Nothing to do for PHIs and BR, since we already took care of the 1843249423Sdim // loop control flow instructions. 1844249423Sdim continue; 1845249423Sdim case Instruction::PHI:{ 1846249423Sdim PHINode* P = cast<PHINode>(it); 1847249423Sdim // Handle reduction variables: 1848249423Sdim if (Legal->getReductionVars()->count(P)) { 1849249423Sdim for (unsigned part = 0; part < UF; ++part) { 1850249423Sdim // This is phase one of vectorizing PHIs. 1851249423Sdim Type *VecTy = VectorType::get(it->getType(), VF); 1852249423Sdim Entry[part] = PHINode::Create(VecTy, 2, "vec.phi", 1853249423Sdim LoopVectorBody-> getFirstInsertionPt()); 1854249423Sdim } 1855249423Sdim PV->push_back(P); 1856249423Sdim continue; 1857249423Sdim } 1858249423Sdim 1859249423Sdim // Check for PHI nodes that are lowered to vector selects. 1860249423Sdim if (P->getParent() != OrigLoop->getHeader()) { 1861249423Sdim // We know that all PHIs in non header blocks are converted into 1862249423Sdim // selects, so we don't have to worry about the insertion order and we 1863249423Sdim // can just use the builder. 1864249423Sdim 1865249423Sdim // At this point we generate the predication tree. There may be 1866249423Sdim // duplications since this is a simple recursive scan, but future 1867249423Sdim // optimizations will clean it up. 1868249423Sdim VectorParts Cond = createEdgeMask(P->getIncomingBlock(0), 1869249423Sdim P->getParent()); 1870249423Sdim 1871249423Sdim for (unsigned part = 0; part < UF; ++part) { 1872249423Sdim VectorParts &In0 = getVectorValue(P->getIncomingValue(0)); 1873249423Sdim VectorParts &In1 = getVectorValue(P->getIncomingValue(1)); 1874249423Sdim Entry[part] = Builder.CreateSelect(Cond[part], In0[part], In1[part], 1875249423Sdim "predphi"); 1876249423Sdim } 1877249423Sdim continue; 1878249423Sdim } 1879249423Sdim 1880249423Sdim // This PHINode must be an induction variable. 1881249423Sdim // Make sure that we know about it. 1882249423Sdim assert(Legal->getInductionVars()->count(P) && 1883249423Sdim "Not an induction variable"); 1884249423Sdim 1885249423Sdim LoopVectorizationLegality::InductionInfo II = 1886249423Sdim Legal->getInductionVars()->lookup(P); 1887249423Sdim 1888249423Sdim switch (II.IK) { 1889249423Sdim case LoopVectorizationLegality::IK_NoInduction: 1890249423Sdim llvm_unreachable("Unknown induction"); 1891249423Sdim case LoopVectorizationLegality::IK_IntInduction: { 1892249423Sdim assert(P == OldInduction && "Unexpected PHI"); 1893249423Sdim Value *Broadcasted = getBroadcastInstrs(Induction); 1894249423Sdim // After broadcasting the induction variable we need to make the 1895249423Sdim // vector consecutive by adding 0, 1, 2 ... 1896249423Sdim for (unsigned part = 0; part < UF; ++part) 1897249423Sdim Entry[part] = getConsecutiveVector(Broadcasted, VF * part, false); 1898249423Sdim continue; 1899249423Sdim } 1900249423Sdim case LoopVectorizationLegality::IK_ReverseIntInduction: 1901249423Sdim case LoopVectorizationLegality::IK_PtrInduction: 1902249423Sdim case LoopVectorizationLegality::IK_ReversePtrInduction: 1903249423Sdim // Handle reverse integer and pointer inductions. 1904249423Sdim Value *StartIdx = 0; 1905249423Sdim // If we have a single integer induction variable then use it. 1906249423Sdim // Otherwise, start counting at zero. 1907249423Sdim if (OldInduction) { 1908249423Sdim LoopVectorizationLegality::InductionInfo OldII = 1909249423Sdim Legal->getInductionVars()->lookup(OldInduction); 1910249423Sdim StartIdx = OldII.StartValue; 1911249423Sdim } else { 1912249423Sdim StartIdx = ConstantInt::get(Induction->getType(), 0); 1913249423Sdim } 1914249423Sdim // This is the normalized GEP that starts counting at zero. 1915249423Sdim Value *NormalizedIdx = Builder.CreateSub(Induction, StartIdx, 1916249423Sdim "normalized.idx"); 1917249423Sdim 1918249423Sdim // Handle the reverse integer induction variable case. 1919249423Sdim if (LoopVectorizationLegality::IK_ReverseIntInduction == II.IK) { 1920249423Sdim IntegerType *DstTy = cast<IntegerType>(II.StartValue->getType()); 1921249423Sdim Value *CNI = Builder.CreateSExtOrTrunc(NormalizedIdx, DstTy, 1922249423Sdim "resize.norm.idx"); 1923249423Sdim Value *ReverseInd = Builder.CreateSub(II.StartValue, CNI, 1924249423Sdim "reverse.idx"); 1925249423Sdim 1926249423Sdim // This is a new value so do not hoist it out. 1927249423Sdim Value *Broadcasted = getBroadcastInstrs(ReverseInd); 1928249423Sdim // After broadcasting the induction variable we need to make the 1929249423Sdim // vector consecutive by adding ... -3, -2, -1, 0. 1930249423Sdim for (unsigned part = 0; part < UF; ++part) 1931249423Sdim Entry[part] = getConsecutiveVector(Broadcasted, -VF * part, true); 1932249423Sdim continue; 1933249423Sdim } 1934249423Sdim 1935249423Sdim // Handle the pointer induction variable case. 1936249423Sdim assert(P->getType()->isPointerTy() && "Unexpected type."); 1937249423Sdim 1938249423Sdim // Is this a reverse induction ptr or a consecutive induction ptr. 1939249423Sdim bool Reverse = (LoopVectorizationLegality::IK_ReversePtrInduction == 1940249423Sdim II.IK); 1941249423Sdim 1942249423Sdim // This is the vector of results. Notice that we don't generate 1943249423Sdim // vector geps because scalar geps result in better code. 1944249423Sdim for (unsigned part = 0; part < UF; ++part) { 1945249423Sdim Value *VecVal = UndefValue::get(VectorType::get(P->getType(), VF)); 1946249423Sdim for (unsigned int i = 0; i < VF; ++i) { 1947249423Sdim int EltIndex = (i + part * VF) * (Reverse ? -1 : 1); 1948249423Sdim Constant *Idx = ConstantInt::get(Induction->getType(), EltIndex); 1949249423Sdim Value *GlobalIdx; 1950249423Sdim if (!Reverse) 1951249423Sdim GlobalIdx = Builder.CreateAdd(NormalizedIdx, Idx, "gep.idx"); 1952249423Sdim else 1953249423Sdim GlobalIdx = Builder.CreateSub(Idx, NormalizedIdx, "gep.ridx"); 1954249423Sdim 1955249423Sdim Value *SclrGep = Builder.CreateGEP(II.StartValue, GlobalIdx, 1956249423Sdim "next.gep"); 1957249423Sdim VecVal = Builder.CreateInsertElement(VecVal, SclrGep, 1958249423Sdim Builder.getInt32(i), 1959249423Sdim "insert.gep"); 1960249423Sdim } 1961249423Sdim Entry[part] = VecVal; 1962249423Sdim } 1963249423Sdim continue; 1964249423Sdim } 1965249423Sdim 1966249423Sdim }// End of PHI. 1967249423Sdim 1968249423Sdim case Instruction::Add: 1969249423Sdim case Instruction::FAdd: 1970249423Sdim case Instruction::Sub: 1971249423Sdim case Instruction::FSub: 1972249423Sdim case Instruction::Mul: 1973249423Sdim case Instruction::FMul: 1974249423Sdim case Instruction::UDiv: 1975249423Sdim case Instruction::SDiv: 1976249423Sdim case Instruction::FDiv: 1977249423Sdim case Instruction::URem: 1978249423Sdim case Instruction::SRem: 1979249423Sdim case Instruction::FRem: 1980249423Sdim case Instruction::Shl: 1981249423Sdim case Instruction::LShr: 1982249423Sdim case Instruction::AShr: 1983249423Sdim case Instruction::And: 1984249423Sdim case Instruction::Or: 1985249423Sdim case Instruction::Xor: { 1986249423Sdim // Just widen binops. 1987249423Sdim BinaryOperator *BinOp = dyn_cast<BinaryOperator>(it); 1988249423Sdim VectorParts &A = getVectorValue(it->getOperand(0)); 1989249423Sdim VectorParts &B = getVectorValue(it->getOperand(1)); 1990249423Sdim 1991249423Sdim // Use this vector value for all users of the original instruction. 1992249423Sdim for (unsigned Part = 0; Part < UF; ++Part) { 1993249423Sdim Value *V = Builder.CreateBinOp(BinOp->getOpcode(), A[Part], B[Part]); 1994249423Sdim 1995249423Sdim // Update the NSW, NUW and Exact flags. Notice: V can be an Undef. 1996249423Sdim BinaryOperator *VecOp = dyn_cast<BinaryOperator>(V); 1997249423Sdim if (VecOp && isa<OverflowingBinaryOperator>(BinOp)) { 1998249423Sdim VecOp->setHasNoSignedWrap(BinOp->hasNoSignedWrap()); 1999249423Sdim VecOp->setHasNoUnsignedWrap(BinOp->hasNoUnsignedWrap()); 2000249423Sdim } 2001249423Sdim if (VecOp && isa<PossiblyExactOperator>(VecOp)) 2002249423Sdim VecOp->setIsExact(BinOp->isExact()); 2003249423Sdim 2004249423Sdim Entry[Part] = V; 2005249423Sdim } 2006249423Sdim break; 2007249423Sdim } 2008249423Sdim case Instruction::Select: { 2009249423Sdim // Widen selects. 2010249423Sdim // If the selector is loop invariant we can create a select 2011249423Sdim // instruction with a scalar condition. Otherwise, use vector-select. 2012249423Sdim bool InvariantCond = SE->isLoopInvariant(SE->getSCEV(it->getOperand(0)), 2013249423Sdim OrigLoop); 2014249423Sdim 2015249423Sdim // The condition can be loop invariant but still defined inside the 2016249423Sdim // loop. This means that we can't just use the original 'cond' value. 2017249423Sdim // We have to take the 'vectorized' value and pick the first lane. 2018249423Sdim // Instcombine will make this a no-op. 2019249423Sdim VectorParts &Cond = getVectorValue(it->getOperand(0)); 2020249423Sdim VectorParts &Op0 = getVectorValue(it->getOperand(1)); 2021249423Sdim VectorParts &Op1 = getVectorValue(it->getOperand(2)); 2022249423Sdim Value *ScalarCond = Builder.CreateExtractElement(Cond[0], 2023249423Sdim Builder.getInt32(0)); 2024249423Sdim for (unsigned Part = 0; Part < UF; ++Part) { 2025249423Sdim Entry[Part] = Builder.CreateSelect( 2026249423Sdim InvariantCond ? ScalarCond : Cond[Part], 2027249423Sdim Op0[Part], 2028249423Sdim Op1[Part]); 2029249423Sdim } 2030249423Sdim break; 2031249423Sdim } 2032249423Sdim 2033249423Sdim case Instruction::ICmp: 2034249423Sdim case Instruction::FCmp: { 2035249423Sdim // Widen compares. Generate vector compares. 2036249423Sdim bool FCmp = (it->getOpcode() == Instruction::FCmp); 2037249423Sdim CmpInst *Cmp = dyn_cast<CmpInst>(it); 2038249423Sdim VectorParts &A = getVectorValue(it->getOperand(0)); 2039249423Sdim VectorParts &B = getVectorValue(it->getOperand(1)); 2040249423Sdim for (unsigned Part = 0; Part < UF; ++Part) { 2041249423Sdim Value *C = 0; 2042249423Sdim if (FCmp) 2043249423Sdim C = Builder.CreateFCmp(Cmp->getPredicate(), A[Part], B[Part]); 2044249423Sdim else 2045249423Sdim C = Builder.CreateICmp(Cmp->getPredicate(), A[Part], B[Part]); 2046249423Sdim Entry[Part] = C; 2047249423Sdim } 2048249423Sdim break; 2049249423Sdim } 2050249423Sdim 2051249423Sdim case Instruction::Store: 2052249423Sdim case Instruction::Load: 2053249423Sdim vectorizeMemoryInstruction(it, Legal); 2054249423Sdim break; 2055249423Sdim case Instruction::ZExt: 2056249423Sdim case Instruction::SExt: 2057249423Sdim case Instruction::FPToUI: 2058249423Sdim case Instruction::FPToSI: 2059249423Sdim case Instruction::FPExt: 2060249423Sdim case Instruction::PtrToInt: 2061249423Sdim case Instruction::IntToPtr: 2062249423Sdim case Instruction::SIToFP: 2063249423Sdim case Instruction::UIToFP: 2064249423Sdim case Instruction::Trunc: 2065249423Sdim case Instruction::FPTrunc: 2066249423Sdim case Instruction::BitCast: { 2067249423Sdim CastInst *CI = dyn_cast<CastInst>(it); 2068249423Sdim /// Optimize the special case where the source is the induction 2069249423Sdim /// variable. Notice that we can only optimize the 'trunc' case 2070249423Sdim /// because: a. FP conversions lose precision, b. sext/zext may wrap, 2071249423Sdim /// c. other casts depend on pointer size. 2072249423Sdim if (CI->getOperand(0) == OldInduction && 2073249423Sdim it->getOpcode() == Instruction::Trunc) { 2074249423Sdim Value *ScalarCast = Builder.CreateCast(CI->getOpcode(), Induction, 2075249423Sdim CI->getType()); 2076249423Sdim Value *Broadcasted = getBroadcastInstrs(ScalarCast); 2077249423Sdim for (unsigned Part = 0; Part < UF; ++Part) 2078249423Sdim Entry[Part] = getConsecutiveVector(Broadcasted, VF * Part, false); 2079249423Sdim break; 2080249423Sdim } 2081249423Sdim /// Vectorize casts. 2082249423Sdim Type *DestTy = VectorType::get(CI->getType()->getScalarType(), VF); 2083249423Sdim 2084249423Sdim VectorParts &A = getVectorValue(it->getOperand(0)); 2085249423Sdim for (unsigned Part = 0; Part < UF; ++Part) 2086249423Sdim Entry[Part] = Builder.CreateCast(CI->getOpcode(), A[Part], DestTy); 2087249423Sdim break; 2088249423Sdim } 2089249423Sdim 2090249423Sdim case Instruction::Call: { 2091249423Sdim // Ignore dbg intrinsics. 2092249423Sdim if (isa<DbgInfoIntrinsic>(it)) 2093249423Sdim break; 2094249423Sdim 2095249423Sdim Module *M = BB->getParent()->getParent(); 2096249423Sdim CallInst *CI = cast<CallInst>(it); 2097249423Sdim Intrinsic::ID ID = getIntrinsicIDForCall(CI, TLI); 2098249423Sdim assert(ID && "Not an intrinsic call!"); 2099249423Sdim for (unsigned Part = 0; Part < UF; ++Part) { 2100249423Sdim SmallVector<Value*, 4> Args; 2101249423Sdim for (unsigned i = 0, ie = CI->getNumArgOperands(); i != ie; ++i) { 2102249423Sdim VectorParts &Arg = getVectorValue(CI->getArgOperand(i)); 2103249423Sdim Args.push_back(Arg[Part]); 2104249423Sdim } 2105249423Sdim Type *Tys[] = { VectorType::get(CI->getType()->getScalarType(), VF) }; 2106249423Sdim Function *F = Intrinsic::getDeclaration(M, ID, Tys); 2107249423Sdim Entry[Part] = Builder.CreateCall(F, Args); 2108249423Sdim } 2109249423Sdim break; 2110249423Sdim } 2111249423Sdim 2112249423Sdim default: 2113249423Sdim // All other instructions are unsupported. Scalarize them. 2114249423Sdim scalarizeInstruction(it); 2115249423Sdim break; 2116249423Sdim }// end of switch. 2117249423Sdim }// end of for_each instr. 2118249423Sdim} 2119249423Sdim 2120249423Sdimvoid InnerLoopVectorizer::updateAnalysis() { 2121249423Sdim // Forget the original basic block. 2122243789Sdim SE->forgetLoop(OrigLoop); 2123243789Sdim 2124243789Sdim // Update the dominator tree information. 2125249423Sdim assert(DT->properlyDominates(LoopBypassBlocks.front(), LoopExitBlock) && 2126243789Sdim "Entry does not dominate exit."); 2127243789Sdim 2128249423Sdim for (unsigned I = 1, E = LoopBypassBlocks.size(); I != E; ++I) 2129249423Sdim DT->addNewBlock(LoopBypassBlocks[I], LoopBypassBlocks[I-1]); 2130249423Sdim DT->addNewBlock(LoopVectorPreHeader, LoopBypassBlocks.back()); 2131243789Sdim DT->addNewBlock(LoopVectorBody, LoopVectorPreHeader); 2132249423Sdim DT->addNewBlock(LoopMiddleBlock, LoopBypassBlocks.front()); 2133243789Sdim DT->addNewBlock(LoopScalarPreHeader, LoopMiddleBlock); 2134243789Sdim DT->changeImmediateDominator(LoopScalarBody, LoopScalarPreHeader); 2135243789Sdim DT->changeImmediateDominator(LoopExitBlock, LoopMiddleBlock); 2136243789Sdim 2137243789Sdim DEBUG(DT->verifyAnalysis()); 2138243789Sdim} 2139243789Sdim 2140249423Sdimbool LoopVectorizationLegality::canVectorizeWithIfConvert() { 2141249423Sdim if (!EnableIfConversion) 2142249423Sdim return false; 2143249423Sdim 2144249423Sdim assert(TheLoop->getNumBlocks() > 1 && "Single block loops are vectorizable"); 2145249423Sdim std::vector<BasicBlock*> &LoopBlocks = TheLoop->getBlocksVector(); 2146249423Sdim 2147249423Sdim // Collect the blocks that need predication. 2148249423Sdim for (unsigned i = 0, e = LoopBlocks.size(); i < e; ++i) { 2149249423Sdim BasicBlock *BB = LoopBlocks[i]; 2150249423Sdim 2151249423Sdim // We don't support switch statements inside loops. 2152249423Sdim if (!isa<BranchInst>(BB->getTerminator())) 2153249423Sdim return false; 2154249423Sdim 2155249423Sdim // We must have at most two predecessors because we need to convert 2156249423Sdim // all PHIs to selects. 2157249423Sdim unsigned Preds = std::distance(pred_begin(BB), pred_end(BB)); 2158249423Sdim if (Preds > 2) 2159249423Sdim return false; 2160249423Sdim 2161249423Sdim // We must be able to predicate all blocks that need to be predicated. 2162249423Sdim if (blockNeedsPredication(BB) && !blockCanBePredicated(BB)) 2163249423Sdim return false; 2164243789Sdim } 2165243789Sdim 2166249423Sdim // We can if-convert this loop. 2167249423Sdim return true; 2168249423Sdim} 2169249423Sdim 2170249423Sdimbool LoopVectorizationLegality::canVectorize() { 2171249423Sdim assert(TheLoop->getLoopPreheader() && "No preheader!!"); 2172249423Sdim 2173249423Sdim // We can only vectorize innermost loops. 2174249423Sdim if (TheLoop->getSubLoopsVector().size()) 2175249423Sdim return false; 2176249423Sdim 2177249423Sdim // We must have a single backedge. 2178249423Sdim if (TheLoop->getNumBackEdges() != 1) 2179249423Sdim return false; 2180249423Sdim 2181249423Sdim // We must have a single exiting block. 2182249423Sdim if (!TheLoop->getExitingBlock()) 2183249423Sdim return false; 2184249423Sdim 2185243789Sdim unsigned NumBlocks = TheLoop->getNumBlocks(); 2186249423Sdim 2187249423Sdim // Check if we can if-convert non single-bb loops. 2188249423Sdim if (NumBlocks != 1 && !canVectorizeWithIfConvert()) { 2189249423Sdim DEBUG(dbgs() << "LV: Can't if-convert the loop.\n"); 2190243789Sdim return false; 2191243789Sdim } 2192243789Sdim 2193243789Sdim // We need to have a loop header. 2194249423Sdim BasicBlock *Latch = TheLoop->getLoopLatch(); 2195249423Sdim DEBUG(dbgs() << "LV: Found a loop: " << 2196249423Sdim TheLoop->getHeader()->getName() << "\n"); 2197243789Sdim 2198243789Sdim // ScalarEvolution needs to be able to find the exit count. 2199249423Sdim const SCEV *ExitCount = SE->getExitCount(TheLoop, Latch); 2200243789Sdim if (ExitCount == SE->getCouldNotCompute()) { 2201243789Sdim DEBUG(dbgs() << "LV: SCEV could not compute the loop exit count.\n"); 2202243789Sdim return false; 2203243789Sdim } 2204243789Sdim 2205243789Sdim // Do not loop-vectorize loops with a tiny trip count. 2206249423Sdim unsigned TC = SE->getSmallConstantTripCount(TheLoop, Latch); 2207249423Sdim if (TC > 0u && TC < TinyTripCountVectorThreshold) { 2208243789Sdim DEBUG(dbgs() << "LV: Found a loop with a very small trip count. " << 2209243789Sdim "This loop is not worth vectorizing.\n"); 2210243789Sdim return false; 2211243789Sdim } 2212243789Sdim 2213249423Sdim // Check if we can vectorize the instructions and CFG in this loop. 2214249423Sdim if (!canVectorizeInstrs()) { 2215249423Sdim DEBUG(dbgs() << "LV: Can't vectorize the instructions or CFG\n"); 2216249423Sdim return false; 2217249423Sdim } 2218249423Sdim 2219243789Sdim // Go over each instruction and look at memory deps. 2220249423Sdim if (!canVectorizeMemory()) { 2221249423Sdim DEBUG(dbgs() << "LV: Can't vectorize due to memory conflicts\n"); 2222243789Sdim return false; 2223243789Sdim } 2224243789Sdim 2225249423Sdim // Collect all of the variables that remain uniform after vectorization. 2226249423Sdim collectLoopUniforms(); 2227249423Sdim 2228243789Sdim DEBUG(dbgs() << "LV: We can vectorize this loop" << 2229243789Sdim (PtrRtCheck.Need ? " (with a runtime bound check)" : "") 2230243789Sdim <<"!\n"); 2231243789Sdim 2232243789Sdim // Okay! We can vectorize. At this point we don't have any other mem analysis 2233243789Sdim // which may limit our maximum vectorization factor, so just return true with 2234243789Sdim // no restrictions. 2235243789Sdim return true; 2236243789Sdim} 2237243789Sdim 2238249423Sdimbool LoopVectorizationLegality::canVectorizeInstrs() { 2239249423Sdim BasicBlock *PreHeader = TheLoop->getLoopPreheader(); 2240249423Sdim BasicBlock *Header = TheLoop->getHeader(); 2241243789Sdim 2242249423Sdim // If we marked the scalar loop as "already vectorized" then no need 2243249423Sdim // to vectorize it again. 2244249423Sdim if (Header->getTerminator()->getMetadata(AlreadyVectorizedMDName)) { 2245249423Sdim DEBUG(dbgs() << "LV: This loop was vectorized before\n"); 2246249423Sdim return false; 2247249423Sdim } 2248249423Sdim 2249249423Sdim // For each block in the loop. 2250249423Sdim for (Loop::block_iterator bb = TheLoop->block_begin(), 2251249423Sdim be = TheLoop->block_end(); bb != be; ++bb) { 2252249423Sdim 2253249423Sdim // Scan the instructions in the block and look for hazards. 2254249423Sdim for (BasicBlock::iterator it = (*bb)->begin(), e = (*bb)->end(); it != e; 2255249423Sdim ++it) { 2256249423Sdim 2257249423Sdim if (PHINode *Phi = dyn_cast<PHINode>(it)) { 2258249423Sdim // This should not happen because the loop should be normalized. 2259249423Sdim if (Phi->getNumIncomingValues() != 2) { 2260249423Sdim DEBUG(dbgs() << "LV: Found an invalid PHI.\n"); 2261249423Sdim return false; 2262249423Sdim } 2263249423Sdim 2264249423Sdim // Check that this PHI type is allowed. 2265249423Sdim if (!Phi->getType()->isIntegerTy() && 2266249423Sdim !Phi->getType()->isFloatingPointTy() && 2267249423Sdim !Phi->getType()->isPointerTy()) { 2268249423Sdim DEBUG(dbgs() << "LV: Found an non-int non-pointer PHI.\n"); 2269249423Sdim return false; 2270249423Sdim } 2271249423Sdim 2272249423Sdim // If this PHINode is not in the header block, then we know that we 2273249423Sdim // can convert it to select during if-conversion. No need to check if 2274249423Sdim // the PHIs in this block are induction or reduction variables. 2275249423Sdim if (*bb != Header) 2276249423Sdim continue; 2277249423Sdim 2278249423Sdim // This is the value coming from the preheader. 2279249423Sdim Value *StartValue = Phi->getIncomingValueForBlock(PreHeader); 2280249423Sdim // Check if this is an induction variable. 2281249423Sdim InductionKind IK = isInductionVariable(Phi); 2282249423Sdim 2283249423Sdim if (IK_NoInduction != IK) { 2284249423Sdim // Int inductions are special because we only allow one IV. 2285249423Sdim if (IK == IK_IntInduction) { 2286249423Sdim if (Induction) { 2287249423Sdim DEBUG(dbgs() << "LV: Found too many inductions."<< *Phi <<"\n"); 2288249423Sdim return false; 2289249423Sdim } 2290249423Sdim Induction = Phi; 2291249423Sdim } 2292249423Sdim 2293249423Sdim DEBUG(dbgs() << "LV: Found an induction variable.\n"); 2294249423Sdim Inductions[Phi] = InductionInfo(StartValue, IK); 2295249423Sdim continue; 2296249423Sdim } 2297249423Sdim 2298249423Sdim if (AddReductionVar(Phi, RK_IntegerAdd)) { 2299249423Sdim DEBUG(dbgs() << "LV: Found an ADD reduction PHI."<< *Phi <<"\n"); 2300249423Sdim continue; 2301249423Sdim } 2302249423Sdim if (AddReductionVar(Phi, RK_IntegerMult)) { 2303249423Sdim DEBUG(dbgs() << "LV: Found a MUL reduction PHI."<< *Phi <<"\n"); 2304249423Sdim continue; 2305249423Sdim } 2306249423Sdim if (AddReductionVar(Phi, RK_IntegerOr)) { 2307249423Sdim DEBUG(dbgs() << "LV: Found an OR reduction PHI."<< *Phi <<"\n"); 2308249423Sdim continue; 2309249423Sdim } 2310249423Sdim if (AddReductionVar(Phi, RK_IntegerAnd)) { 2311249423Sdim DEBUG(dbgs() << "LV: Found an AND reduction PHI."<< *Phi <<"\n"); 2312249423Sdim continue; 2313249423Sdim } 2314249423Sdim if (AddReductionVar(Phi, RK_IntegerXor)) { 2315249423Sdim DEBUG(dbgs() << "LV: Found a XOR reduction PHI."<< *Phi <<"\n"); 2316249423Sdim continue; 2317249423Sdim } 2318249423Sdim if (AddReductionVar(Phi, RK_FloatMult)) { 2319249423Sdim DEBUG(dbgs() << "LV: Found an FMult reduction PHI."<< *Phi <<"\n"); 2320249423Sdim continue; 2321249423Sdim } 2322249423Sdim if (AddReductionVar(Phi, RK_FloatAdd)) { 2323249423Sdim DEBUG(dbgs() << "LV: Found an FAdd reduction PHI."<< *Phi <<"\n"); 2324249423Sdim continue; 2325249423Sdim } 2326249423Sdim 2327249423Sdim DEBUG(dbgs() << "LV: Found an unidentified PHI."<< *Phi <<"\n"); 2328243789Sdim return false; 2329249423Sdim }// end of PHI handling 2330249423Sdim 2331249423Sdim // We still don't handle functions. However, we can ignore dbg intrinsic 2332249423Sdim // calls and we do handle certain intrinsic and libm functions. 2333249423Sdim CallInst *CI = dyn_cast<CallInst>(it); 2334249423Sdim if (CI && !getIntrinsicIDForCall(CI, TLI) && !isa<DbgInfoIntrinsic>(CI)) { 2335249423Sdim DEBUG(dbgs() << "LV: Found a call site.\n"); 2336249423Sdim return false; 2337243789Sdim } 2338249423Sdim 2339249423Sdim // Check that the instruction return type is vectorizable. 2340249423Sdim if (!VectorType::isValidElementType(it->getType()) && 2341249423Sdim !it->getType()->isVoidTy()) { 2342249423Sdim DEBUG(dbgs() << "LV: Found unvectorizable type." << "\n"); 2343243789Sdim return false; 2344243789Sdim } 2345243789Sdim 2346249423Sdim // Check that the stored type is vectorizable. 2347249423Sdim if (StoreInst *ST = dyn_cast<StoreInst>(it)) { 2348249423Sdim Type *T = ST->getValueOperand()->getType(); 2349249423Sdim if (!VectorType::isValidElementType(T)) 2350243789Sdim return false; 2351243789Sdim } 2352243789Sdim 2353249423Sdim // Reduction instructions are allowed to have exit users. 2354249423Sdim // All other instructions must not have external users. 2355249423Sdim if (!AllowedExit.count(it)) 2356249423Sdim //Check that all of the users of the loop are inside the BB. 2357249423Sdim for (Value::use_iterator I = it->use_begin(), E = it->use_end(); 2358249423Sdim I != E; ++I) { 2359249423Sdim Instruction *U = cast<Instruction>(*I); 2360249423Sdim // This user may be a reduction exit value. 2361249423Sdim if (!TheLoop->contains(U)) { 2362249423Sdim DEBUG(dbgs() << "LV: Found an outside user for : "<< *U << "\n"); 2363249423Sdim return false; 2364249423Sdim } 2365249423Sdim } 2366249423Sdim } // next instr. 2367243789Sdim 2368249423Sdim } 2369243789Sdim 2370243789Sdim if (!Induction) { 2371249423Sdim DEBUG(dbgs() << "LV: Did not find one integer induction var.\n"); 2372249423Sdim assert(getInductionVars()->size() && "No induction variables"); 2373243789Sdim } 2374243789Sdim 2375249423Sdim return true; 2376249423Sdim} 2377243789Sdim 2378249423Sdimvoid LoopVectorizationLegality::collectLoopUniforms() { 2379243789Sdim // We now know that the loop is vectorizable! 2380243789Sdim // Collect variables that will remain uniform after vectorization. 2381243789Sdim std::vector<Value*> Worklist; 2382249423Sdim BasicBlock *Latch = TheLoop->getLoopLatch(); 2383243789Sdim 2384243789Sdim // Start with the conditional branch and walk up the block. 2385249423Sdim Worklist.push_back(Latch->getTerminator()->getOperand(0)); 2386243789Sdim 2387243789Sdim while (Worklist.size()) { 2388243789Sdim Instruction *I = dyn_cast<Instruction>(Worklist.back()); 2389243789Sdim Worklist.pop_back(); 2390243789Sdim 2391249423Sdim // Look at instructions inside this loop. 2392243789Sdim // Stop when reaching PHI nodes. 2393249423Sdim // TODO: we need to follow values all over the loop, not only in this block. 2394249423Sdim if (!I || !TheLoop->contains(I) || isa<PHINode>(I)) 2395249423Sdim continue; 2396243789Sdim 2397243789Sdim // This is a known uniform. 2398243789Sdim Uniforms.insert(I); 2399243789Sdim 2400243789Sdim // Insert all operands. 2401249423Sdim for (int i = 0, Op = I->getNumOperands(); i < Op; ++i) { 2402243789Sdim Worklist.push_back(I->getOperand(i)); 2403243789Sdim } 2404243789Sdim } 2405249423Sdim} 2406243789Sdim 2407249423SdimAliasAnalysis::Location 2408249423SdimLoopVectorizationLegality::getLoadStoreLocation(Instruction *Inst) { 2409249423Sdim if (StoreInst *Store = dyn_cast<StoreInst>(Inst)) 2410249423Sdim return AA->getLocation(Store); 2411249423Sdim else if (LoadInst *Load = dyn_cast<LoadInst>(Inst)) 2412249423Sdim return AA->getLocation(Load); 2413249423Sdim 2414249423Sdim llvm_unreachable("Should be either load or store instruction"); 2415243789Sdim} 2416243789Sdim 2417249423Sdimbool 2418249423SdimLoopVectorizationLegality::hasPossibleGlobalWriteReorder( 2419249423Sdim Value *Object, 2420249423Sdim Instruction *Inst, 2421249423Sdim AliasMultiMap& WriteObjects, 2422249423Sdim unsigned MaxByteWidth) { 2423249423Sdim 2424249423Sdim AliasAnalysis::Location ThisLoc = getLoadStoreLocation(Inst); 2425249423Sdim 2426249423Sdim std::vector<Instruction*>::iterator 2427249423Sdim it = WriteObjects[Object].begin(), 2428249423Sdim end = WriteObjects[Object].end(); 2429249423Sdim 2430249423Sdim for (; it != end; ++it) { 2431249423Sdim Instruction* I = *it; 2432249423Sdim if (I == Inst) 2433249423Sdim continue; 2434249423Sdim 2435249423Sdim AliasAnalysis::Location ThatLoc = getLoadStoreLocation(I); 2436249423Sdim if (AA->alias(ThisLoc.getWithNewSize(MaxByteWidth), 2437249423Sdim ThatLoc.getWithNewSize(MaxByteWidth))) 2438249423Sdim return true; 2439249423Sdim } 2440249423Sdim return false; 2441249423Sdim} 2442249423Sdim 2443249423Sdimbool LoopVectorizationLegality::canVectorizeMemory() { 2444249423Sdim 2445249423Sdim if (TheLoop->isAnnotatedParallel()) { 2446249423Sdim DEBUG(dbgs() 2447249423Sdim << "LV: A loop annotated parallel, ignore memory dependency " 2448249423Sdim << "checks.\n"); 2449249423Sdim return true; 2450249423Sdim } 2451249423Sdim 2452243789Sdim typedef SmallVector<Value*, 16> ValueVector; 2453243789Sdim typedef SmallPtrSet<Value*, 16> ValueSet; 2454243789Sdim // Holds the Load and Store *instructions*. 2455243789Sdim ValueVector Loads; 2456243789Sdim ValueVector Stores; 2457243789Sdim PtrRtCheck.Pointers.clear(); 2458243789Sdim PtrRtCheck.Need = false; 2459243789Sdim 2460249423Sdim // For each block. 2461249423Sdim for (Loop::block_iterator bb = TheLoop->block_begin(), 2462249423Sdim be = TheLoop->block_end(); bb != be; ++bb) { 2463243789Sdim 2464249423Sdim // Scan the BB and collect legal loads and stores. 2465249423Sdim for (BasicBlock::iterator it = (*bb)->begin(), e = (*bb)->end(); it != e; 2466249423Sdim ++it) { 2467249423Sdim 2468249423Sdim // If this is a load, save it. If this instruction can read from memory 2469249423Sdim // but is not a load, then we quit. Notice that we don't handle function 2470249423Sdim // calls that read or write. 2471249423Sdim if (it->mayReadFromMemory()) { 2472249423Sdim LoadInst *Ld = dyn_cast<LoadInst>(it); 2473249423Sdim if (!Ld) return false; 2474249423Sdim if (!Ld->isSimple()) { 2475249423Sdim DEBUG(dbgs() << "LV: Found a non-simple load.\n"); 2476249423Sdim return false; 2477249423Sdim } 2478249423Sdim Loads.push_back(Ld); 2479249423Sdim continue; 2480243789Sdim } 2481243789Sdim 2482249423Sdim // Save 'store' instructions. Abort if other instructions write to memory. 2483249423Sdim if (it->mayWriteToMemory()) { 2484249423Sdim StoreInst *St = dyn_cast<StoreInst>(it); 2485249423Sdim if (!St) return false; 2486249423Sdim if (!St->isSimple()) { 2487249423Sdim DEBUG(dbgs() << "LV: Found a non-simple store.\n"); 2488249423Sdim return false; 2489249423Sdim } 2490249423Sdim Stores.push_back(St); 2491243789Sdim } 2492249423Sdim } // next instr. 2493249423Sdim } // next block. 2494243789Sdim 2495243789Sdim // Now we have two lists that hold the loads and the stores. 2496243789Sdim // Next, we find the pointers that they use. 2497243789Sdim 2498243789Sdim // Check if we see any stores. If there are no stores, then we don't 2499243789Sdim // care if the pointers are *restrict*. 2500243789Sdim if (!Stores.size()) { 2501249423Sdim DEBUG(dbgs() << "LV: Found a read-only loop!\n"); 2502249423Sdim return true; 2503243789Sdim } 2504243789Sdim 2505249423Sdim // Holds the read and read-write *pointers* that we find. These maps hold 2506249423Sdim // unique values for pointers (so no need for multi-map). 2507249423Sdim AliasMap Reads; 2508249423Sdim AliasMap ReadWrites; 2509243789Sdim 2510243789Sdim // Holds the analyzed pointers. We don't want to call GetUnderlyingObjects 2511243789Sdim // multiple times on the same object. If the ptr is accessed twice, once 2512243789Sdim // for read and once for write, it will only appear once (on the write 2513243789Sdim // list). This is okay, since we are going to check for conflicts between 2514243789Sdim // writes and between reads and writes, but not between reads and reads. 2515243789Sdim ValueSet Seen; 2516243789Sdim 2517243789Sdim ValueVector::iterator I, IE; 2518243789Sdim for (I = Stores.begin(), IE = Stores.end(); I != IE; ++I) { 2519249423Sdim StoreInst *ST = cast<StoreInst>(*I); 2520243789Sdim Value* Ptr = ST->getPointerOperand(); 2521243789Sdim 2522243789Sdim if (isUniform(Ptr)) { 2523243789Sdim DEBUG(dbgs() << "LV: We don't allow storing to uniform addresses\n"); 2524243789Sdim return false; 2525243789Sdim } 2526243789Sdim 2527243789Sdim // If we did *not* see this pointer before, insert it to 2528243789Sdim // the read-write list. At this phase it is only a 'write' list. 2529243789Sdim if (Seen.insert(Ptr)) 2530249423Sdim ReadWrites.insert(std::make_pair(Ptr, ST)); 2531243789Sdim } 2532243789Sdim 2533243789Sdim for (I = Loads.begin(), IE = Loads.end(); I != IE; ++I) { 2534249423Sdim LoadInst *LD = cast<LoadInst>(*I); 2535243789Sdim Value* Ptr = LD->getPointerOperand(); 2536243789Sdim // If we did *not* see this pointer before, insert it to the 2537243789Sdim // read list. If we *did* see it before, then it is already in 2538243789Sdim // the read-write list. This allows us to vectorize expressions 2539243789Sdim // such as A[i] += x; Because the address of A[i] is a read-write 2540243789Sdim // pointer. This only works if the index of A[i] is consecutive. 2541243789Sdim // If the address of i is unknown (for example A[B[i]]) then we may 2542243789Sdim // read a few words, modify, and write a few words, and some of the 2543243789Sdim // words may be written to the same address. 2544249423Sdim if (Seen.insert(Ptr) || 0 == isConsecutivePtr(Ptr)) 2545249423Sdim Reads.insert(std::make_pair(Ptr, LD)); 2546243789Sdim } 2547243789Sdim 2548243789Sdim // If we write (or read-write) to a single destination and there are no 2549243789Sdim // other reads in this loop then is it safe to vectorize. 2550243789Sdim if (ReadWrites.size() == 1 && Reads.size() == 0) { 2551243789Sdim DEBUG(dbgs() << "LV: Found a write-only loop!\n"); 2552243789Sdim return true; 2553243789Sdim } 2554243789Sdim 2555243789Sdim // Find pointers with computable bounds. We are going to use this information 2556243789Sdim // to place a runtime bound check. 2557249423Sdim bool CanDoRT = true; 2558249423Sdim AliasMap::iterator MI, ME; 2559249423Sdim for (MI = ReadWrites.begin(), ME = ReadWrites.end(); MI != ME; ++MI) { 2560249423Sdim Value *V = (*MI).first; 2561249423Sdim if (hasComputableBounds(V)) { 2562249423Sdim PtrRtCheck.insert(SE, TheLoop, V); 2563249423Sdim DEBUG(dbgs() << "LV: Found a runtime check ptr:" << *V <<"\n"); 2564243789Sdim } else { 2565249423Sdim CanDoRT = false; 2566243789Sdim break; 2567243789Sdim } 2568249423Sdim } 2569249423Sdim for (MI = Reads.begin(), ME = Reads.end(); MI != ME; ++MI) { 2570249423Sdim Value *V = (*MI).first; 2571249423Sdim if (hasComputableBounds(V)) { 2572249423Sdim PtrRtCheck.insert(SE, TheLoop, V); 2573249423Sdim DEBUG(dbgs() << "LV: Found a runtime check ptr:" << *V <<"\n"); 2574243789Sdim } else { 2575249423Sdim CanDoRT = false; 2576243789Sdim break; 2577243789Sdim } 2578249423Sdim } 2579243789Sdim 2580243789Sdim // Check that we did not collect too many pointers or found a 2581243789Sdim // unsizeable pointer. 2582249423Sdim if (!CanDoRT || PtrRtCheck.Pointers.size() > RuntimeMemoryCheckThreshold) { 2583249423Sdim PtrRtCheck.reset(); 2584249423Sdim CanDoRT = false; 2585243789Sdim } 2586243789Sdim 2587249423Sdim if (CanDoRT) { 2588243789Sdim DEBUG(dbgs() << "LV: We can perform a memory runtime check if needed.\n"); 2589243789Sdim } 2590243789Sdim 2591249423Sdim bool NeedRTCheck = false; 2592249423Sdim 2593249423Sdim // Biggest vectorized access possible, vector width * unroll factor. 2594249423Sdim // TODO: We're being very pessimistic here, find a way to know the 2595249423Sdim // real access width before getting here. 2596249423Sdim unsigned MaxByteWidth = (TTI->getRegisterBitWidth(true) / 8) * 2597249423Sdim TTI->getMaximumUnrollFactor(); 2598243789Sdim // Now that the pointers are in two lists (Reads and ReadWrites), we 2599243789Sdim // can check that there are no conflicts between each of the writes and 2600243789Sdim // between the writes to the reads. 2601249423Sdim // Note that WriteObjects duplicates the stores (indexed now by underlying 2602249423Sdim // objects) to avoid pointing to elements inside ReadWrites. 2603249423Sdim // TODO: Maybe create a new type where they can interact without duplication. 2604249423Sdim AliasMultiMap WriteObjects; 2605243789Sdim ValueVector TempObjects; 2606243789Sdim 2607243789Sdim // Check that the read-writes do not conflict with other read-write 2608243789Sdim // pointers. 2609249423Sdim bool AllWritesIdentified = true; 2610249423Sdim for (MI = ReadWrites.begin(), ME = ReadWrites.end(); MI != ME; ++MI) { 2611249423Sdim Value *Val = (*MI).first; 2612249423Sdim Instruction *Inst = (*MI).second; 2613249423Sdim 2614249423Sdim GetUnderlyingObjects(Val, TempObjects, DL); 2615249423Sdim for (ValueVector::iterator UI=TempObjects.begin(), UE=TempObjects.end(); 2616249423Sdim UI != UE; ++UI) { 2617249423Sdim if (!isIdentifiedObject(*UI)) { 2618249423Sdim DEBUG(dbgs() << "LV: Found an unidentified write ptr:"<< **UI <<"\n"); 2619249423Sdim NeedRTCheck = true; 2620249423Sdim AllWritesIdentified = false; 2621243789Sdim } 2622249423Sdim 2623249423Sdim // Never seen it before, can't alias. 2624249423Sdim if (WriteObjects[*UI].empty()) { 2625249423Sdim DEBUG(dbgs() << "LV: Adding Underlying value:" << **UI <<"\n"); 2626249423Sdim WriteObjects[*UI].push_back(Inst); 2627249423Sdim continue; 2628249423Sdim } 2629249423Sdim // Direct alias found. 2630249423Sdim if (!AA || dyn_cast<GlobalValue>(*UI) == NULL) { 2631243789Sdim DEBUG(dbgs() << "LV: Found a possible write-write reorder:" 2632249423Sdim << **UI <<"\n"); 2633249423Sdim return false; 2634243789Sdim } 2635249423Sdim DEBUG(dbgs() << "LV: Found a conflicting global value:" 2636249423Sdim << **UI <<"\n"); 2637249423Sdim DEBUG(dbgs() << "LV: While examining store:" << *Inst <<"\n"); 2638249423Sdim DEBUG(dbgs() << "LV: On value:" << *Val <<"\n"); 2639249423Sdim 2640249423Sdim // If global alias, make sure they do alias. 2641249423Sdim if (hasPossibleGlobalWriteReorder(*UI, 2642249423Sdim Inst, 2643249423Sdim WriteObjects, 2644249423Sdim MaxByteWidth)) { 2645249423Sdim DEBUG(dbgs() << "LV: Found a possible write-write reorder:" 2646249423Sdim << *UI <<"\n"); 2647249423Sdim return false; 2648249423Sdim } 2649249423Sdim 2650249423Sdim // Didn't alias, insert into map for further reference. 2651249423Sdim WriteObjects[*UI].push_back(Inst); 2652243789Sdim } 2653243789Sdim TempObjects.clear(); 2654243789Sdim } 2655243789Sdim 2656243789Sdim /// Check that the reads don't conflict with the read-writes. 2657249423Sdim for (MI = Reads.begin(), ME = Reads.end(); MI != ME; ++MI) { 2658249423Sdim Value *Val = (*MI).first; 2659249423Sdim GetUnderlyingObjects(Val, TempObjects, DL); 2660249423Sdim for (ValueVector::iterator UI=TempObjects.begin(), UE=TempObjects.end(); 2661249423Sdim UI != UE; ++UI) { 2662249423Sdim // If all of the writes are identified then we don't care if the read 2663249423Sdim // pointer is identified or not. 2664249423Sdim if (!AllWritesIdentified && !isIdentifiedObject(*UI)) { 2665249423Sdim DEBUG(dbgs() << "LV: Found an unidentified read ptr:"<< **UI <<"\n"); 2666249423Sdim NeedRTCheck = true; 2667243789Sdim } 2668249423Sdim 2669249423Sdim // Never seen it before, can't alias. 2670249423Sdim if (WriteObjects[*UI].empty()) 2671249423Sdim continue; 2672249423Sdim // Direct alias found. 2673249423Sdim if (!AA || dyn_cast<GlobalValue>(*UI) == NULL) { 2674249423Sdim DEBUG(dbgs() << "LV: Found a possible write-write reorder:" 2675249423Sdim << **UI <<"\n"); 2676249423Sdim return false; 2677243789Sdim } 2678249423Sdim DEBUG(dbgs() << "LV: Found a global value: " 2679249423Sdim << **UI <<"\n"); 2680249423Sdim Instruction *Inst = (*MI).second; 2681249423Sdim DEBUG(dbgs() << "LV: While examining load:" << *Inst <<"\n"); 2682249423Sdim DEBUG(dbgs() << "LV: On value:" << *Val <<"\n"); 2683249423Sdim 2684249423Sdim // If global alias, make sure they do alias. 2685249423Sdim if (hasPossibleGlobalWriteReorder(*UI, 2686249423Sdim Inst, 2687249423Sdim WriteObjects, 2688249423Sdim MaxByteWidth)) { 2689249423Sdim DEBUG(dbgs() << "LV: Found a possible read-write reorder:" 2690249423Sdim << *UI <<"\n"); 2691249423Sdim return false; 2692249423Sdim } 2693243789Sdim } 2694243789Sdim TempObjects.clear(); 2695243789Sdim } 2696243789Sdim 2697249423Sdim PtrRtCheck.Need = NeedRTCheck; 2698249423Sdim if (NeedRTCheck && !CanDoRT) { 2699249423Sdim DEBUG(dbgs() << "LV: We can't vectorize because we can't find " << 2700249423Sdim "the array bounds.\n"); 2701249423Sdim PtrRtCheck.reset(); 2702249423Sdim return false; 2703249423Sdim } 2704249423Sdim 2705249423Sdim DEBUG(dbgs() << "LV: We "<< (NeedRTCheck ? "" : "don't") << 2706249423Sdim " need a runtime memory check.\n"); 2707243789Sdim return true; 2708243789Sdim} 2709243789Sdim 2710243789Sdimbool LoopVectorizationLegality::AddReductionVar(PHINode *Phi, 2711243789Sdim ReductionKind Kind) { 2712243789Sdim if (Phi->getNumIncomingValues() != 2) 2713243789Sdim return false; 2714243789Sdim 2715249423Sdim // Reduction variables are only found in the loop header block. 2716249423Sdim if (Phi->getParent() != TheLoop->getHeader()) 2717249423Sdim return false; 2718243789Sdim 2719249423Sdim // Obtain the reduction start value from the value that comes from the loop 2720249423Sdim // preheader. 2721249423Sdim Value *RdxStart = Phi->getIncomingValueForBlock(TheLoop->getLoopPreheader()); 2722249423Sdim 2723243789Sdim // ExitInstruction is the single value which is used outside the loop. 2724243789Sdim // We only allow for a single reduction value to be used outside the loop. 2725243789Sdim // This includes users of the reduction, variables (which form a cycle 2726243789Sdim // which ends in the phi node). 2727243789Sdim Instruction *ExitInstruction = 0; 2728249423Sdim // Indicates that we found a binary operation in our scan. 2729249423Sdim bool FoundBinOp = false; 2730243789Sdim 2731243789Sdim // Iter is our iterator. We start with the PHI node and scan for all of the 2732249423Sdim // users of this instruction. All users must be instructions that can be 2733243789Sdim // used as reduction variables (such as ADD). We may have a single 2734249423Sdim // out-of-block user. The cycle must end with the original PHI. 2735243789Sdim Instruction *Iter = Phi; 2736243789Sdim while (true) { 2737249423Sdim // If the instruction has no users then this is a broken 2738249423Sdim // chain and can't be a reduction variable. 2739249423Sdim if (Iter->use_empty()) 2740243789Sdim return false; 2741243789Sdim 2742249423Sdim // Did we find a user inside this loop already ? 2743243789Sdim bool FoundInBlockUser = false; 2744249423Sdim // Did we reach the initial PHI node already ? 2745243789Sdim bool FoundStartPHI = false; 2746243789Sdim 2747249423Sdim // Is this a bin op ? 2748249423Sdim FoundBinOp |= !isa<PHINode>(Iter); 2749243789Sdim 2750249423Sdim // Remember the current instruction. 2751249423Sdim Instruction *OldIter = Iter; 2752249423Sdim 2753243789Sdim // For each of the *users* of iter. 2754243789Sdim for (Value::use_iterator it = Iter->use_begin(), e = Iter->use_end(); 2755243789Sdim it != e; ++it) { 2756243789Sdim Instruction *U = cast<Instruction>(*it); 2757243789Sdim // We already know that the PHI is a user. 2758243789Sdim if (U == Phi) { 2759243789Sdim FoundStartPHI = true; 2760243789Sdim continue; 2761243789Sdim } 2762249423Sdim 2763243789Sdim // Check if we found the exit user. 2764243789Sdim BasicBlock *Parent = U->getParent(); 2765249423Sdim if (!TheLoop->contains(Parent)) { 2766249423Sdim // Exit if you find multiple outside users. 2767243789Sdim if (ExitInstruction != 0) 2768243789Sdim return false; 2769243789Sdim ExitInstruction = Iter; 2770243789Sdim } 2771249423Sdim 2772249423Sdim // We allow in-loop PHINodes which are not the original reduction PHI 2773249423Sdim // node. If this PHI is the only user of Iter (happens in IF w/ no ELSE 2774249423Sdim // structure) then don't skip this PHI. 2775249423Sdim if (isa<PHINode>(Iter) && isa<PHINode>(U) && 2776249423Sdim U->getParent() != TheLoop->getHeader() && 2777249423Sdim TheLoop->contains(U) && 2778249423Sdim Iter->hasNUsesOrMore(2)) 2779249423Sdim continue; 2780249423Sdim 2781243789Sdim // We can't have multiple inside users. 2782243789Sdim if (FoundInBlockUser) 2783243789Sdim return false; 2784243789Sdim FoundInBlockUser = true; 2785249423Sdim 2786249423Sdim // Any reduction instr must be of one of the allowed kinds. 2787249423Sdim if (!isReductionInstr(U, Kind)) 2788249423Sdim return false; 2789249423Sdim 2790249423Sdim // Reductions of instructions such as Div, and Sub is only 2791249423Sdim // possible if the LHS is the reduction variable. 2792249423Sdim if (!U->isCommutative() && !isa<PHINode>(U) && U->getOperand(0) != Iter) 2793249423Sdim return false; 2794249423Sdim 2795243789Sdim Iter = U; 2796243789Sdim } 2797243789Sdim 2798249423Sdim // If all uses were skipped this can't be a reduction variable. 2799249423Sdim if (Iter == OldIter) 2800249423Sdim return false; 2801249423Sdim 2802243789Sdim // We found a reduction var if we have reached the original 2803243789Sdim // phi node and we only have a single instruction with out-of-loop 2804243789Sdim // users. 2805249423Sdim if (FoundStartPHI) { 2806249423Sdim // This instruction is allowed to have out-of-loop users. 2807249423Sdim AllowedExit.insert(ExitInstruction); 2808243789Sdim 2809249423Sdim // Save the description of this reduction variable. 2810249423Sdim ReductionDescriptor RD(RdxStart, ExitInstruction, Kind); 2811249423Sdim Reductions[Phi] = RD; 2812249423Sdim // We've ended the cycle. This is a reduction variable if we have an 2813249423Sdim // outside user and it has a binary op. 2814249423Sdim return FoundBinOp && ExitInstruction; 2815249423Sdim } 2816243789Sdim } 2817243789Sdim} 2818243789Sdim 2819243789Sdimbool 2820243789SdimLoopVectorizationLegality::isReductionInstr(Instruction *I, 2821243789Sdim ReductionKind Kind) { 2822249423Sdim bool FP = I->getType()->isFloatingPointTy(); 2823249423Sdim bool FastMath = (FP && I->isCommutative() && I->isAssociative()); 2824249423Sdim 2825249423Sdim switch (I->getOpcode()) { 2826249423Sdim default: 2827249423Sdim return false; 2828249423Sdim case Instruction::PHI: 2829249423Sdim if (FP && (Kind != RK_FloatMult && Kind != RK_FloatAdd)) 2830249423Sdim return false; 2831249423Sdim // possibly. 2832249423Sdim return true; 2833249423Sdim case Instruction::Sub: 2834249423Sdim case Instruction::Add: 2835249423Sdim return Kind == RK_IntegerAdd; 2836249423Sdim case Instruction::SDiv: 2837249423Sdim case Instruction::UDiv: 2838249423Sdim case Instruction::Mul: 2839249423Sdim return Kind == RK_IntegerMult; 2840249423Sdim case Instruction::And: 2841249423Sdim return Kind == RK_IntegerAnd; 2842249423Sdim case Instruction::Or: 2843249423Sdim return Kind == RK_IntegerOr; 2844249423Sdim case Instruction::Xor: 2845249423Sdim return Kind == RK_IntegerXor; 2846249423Sdim case Instruction::FMul: 2847249423Sdim return Kind == RK_FloatMult && FastMath; 2848249423Sdim case Instruction::FAdd: 2849249423Sdim return Kind == RK_FloatAdd && FastMath; 2850249423Sdim } 2851243789Sdim} 2852243789Sdim 2853249423SdimLoopVectorizationLegality::InductionKind 2854249423SdimLoopVectorizationLegality::isInductionVariable(PHINode *Phi) { 2855249423Sdim Type *PhiTy = Phi->getType(); 2856249423Sdim // We only handle integer and pointer inductions variables. 2857249423Sdim if (!PhiTy->isIntegerTy() && !PhiTy->isPointerTy()) 2858249423Sdim return IK_NoInduction; 2859249423Sdim 2860249423Sdim // Check that the PHI is consecutive. 2861243789Sdim const SCEV *PhiScev = SE->getSCEV(Phi); 2862243789Sdim const SCEVAddRecExpr *AR = dyn_cast<SCEVAddRecExpr>(PhiScev); 2863243789Sdim if (!AR) { 2864243789Sdim DEBUG(dbgs() << "LV: PHI is not a poly recurrence.\n"); 2865249423Sdim return IK_NoInduction; 2866243789Sdim } 2867243789Sdim const SCEV *Step = AR->getStepRecurrence(*SE); 2868243789Sdim 2869249423Sdim // Integer inductions need to have a stride of one. 2870249423Sdim if (PhiTy->isIntegerTy()) { 2871249423Sdim if (Step->isOne()) 2872249423Sdim return IK_IntInduction; 2873249423Sdim if (Step->isAllOnesValue()) 2874249423Sdim return IK_ReverseIntInduction; 2875249423Sdim return IK_NoInduction; 2876249423Sdim } 2877249423Sdim 2878249423Sdim // Calculate the pointer stride and check if it is consecutive. 2879249423Sdim const SCEVConstant *C = dyn_cast<SCEVConstant>(Step); 2880249423Sdim if (!C) 2881249423Sdim return IK_NoInduction; 2882249423Sdim 2883249423Sdim assert(PhiTy->isPointerTy() && "The PHI must be a pointer"); 2884249423Sdim uint64_t Size = DL->getTypeAllocSize(PhiTy->getPointerElementType()); 2885249423Sdim if (C->getValue()->equalsInt(Size)) 2886249423Sdim return IK_PtrInduction; 2887249423Sdim else if (C->getValue()->equalsInt(0 - Size)) 2888249423Sdim return IK_ReversePtrInduction; 2889249423Sdim 2890249423Sdim return IK_NoInduction; 2891249423Sdim} 2892249423Sdim 2893249423Sdimbool LoopVectorizationLegality::isInductionVariable(const Value *V) { 2894249423Sdim Value *In0 = const_cast<Value*>(V); 2895249423Sdim PHINode *PN = dyn_cast_or_null<PHINode>(In0); 2896249423Sdim if (!PN) 2897243789Sdim return false; 2898249423Sdim 2899249423Sdim return Inductions.count(PN); 2900249423Sdim} 2901249423Sdim 2902249423Sdimbool LoopVectorizationLegality::blockNeedsPredication(BasicBlock *BB) { 2903249423Sdim assert(TheLoop->contains(BB) && "Unknown block used"); 2904249423Sdim 2905249423Sdim // Blocks that do not dominate the latch need predication. 2906249423Sdim BasicBlock* Latch = TheLoop->getLoopLatch(); 2907249423Sdim return !DT->dominates(BB, Latch); 2908249423Sdim} 2909249423Sdim 2910249423Sdimbool LoopVectorizationLegality::blockCanBePredicated(BasicBlock *BB) { 2911249423Sdim for (BasicBlock::iterator it = BB->begin(), e = BB->end(); it != e; ++it) { 2912249423Sdim // We don't predicate loads/stores at the moment. 2913249423Sdim if (it->mayReadFromMemory() || it->mayWriteToMemory() || it->mayThrow()) 2914249423Sdim return false; 2915249423Sdim 2916249423Sdim // The instructions below can trap. 2917249423Sdim switch (it->getOpcode()) { 2918249423Sdim default: continue; 2919249423Sdim case Instruction::UDiv: 2920249423Sdim case Instruction::SDiv: 2921249423Sdim case Instruction::URem: 2922249423Sdim case Instruction::SRem: 2923249423Sdim return false; 2924249423Sdim } 2925243789Sdim } 2926249423Sdim 2927243789Sdim return true; 2928243789Sdim} 2929243789Sdim 2930243789Sdimbool LoopVectorizationLegality::hasComputableBounds(Value *Ptr) { 2931243789Sdim const SCEV *PhiScev = SE->getSCEV(Ptr); 2932243789Sdim const SCEVAddRecExpr *AR = dyn_cast<SCEVAddRecExpr>(PhiScev); 2933243789Sdim if (!AR) 2934243789Sdim return false; 2935243789Sdim 2936243789Sdim return AR->isAffine(); 2937243789Sdim} 2938243789Sdim 2939249423SdimLoopVectorizationCostModel::VectorizationFactor 2940249423SdimLoopVectorizationCostModel::selectVectorizationFactor(bool OptForSize, 2941249423Sdim unsigned UserVF) { 2942249423Sdim // Width 1 means no vectorize 2943249423Sdim VectorizationFactor Factor = { 1U, 0U }; 2944249423Sdim if (OptForSize && Legal->getRuntimePointerCheck()->Need) { 2945249423Sdim DEBUG(dbgs() << "LV: Aborting. Runtime ptr check is required in Os.\n"); 2946249423Sdim return Factor; 2947243789Sdim } 2948243789Sdim 2949249423Sdim // Find the trip count. 2950249423Sdim unsigned TC = SE->getSmallConstantTripCount(TheLoop, TheLoop->getLoopLatch()); 2951249423Sdim DEBUG(dbgs() << "LV: Found trip count:"<<TC<<"\n"); 2952249423Sdim 2953249423Sdim unsigned WidestType = getWidestType(); 2954249423Sdim unsigned WidestRegister = TTI.getRegisterBitWidth(true); 2955249423Sdim unsigned MaxVectorSize = WidestRegister / WidestType; 2956249423Sdim DEBUG(dbgs() << "LV: The Widest type: " << WidestType << " bits.\n"); 2957249423Sdim DEBUG(dbgs() << "LV: The Widest register is:" << WidestRegister << "bits.\n"); 2958249423Sdim 2959249423Sdim if (MaxVectorSize == 0) { 2960249423Sdim DEBUG(dbgs() << "LV: The target has no vector registers.\n"); 2961249423Sdim MaxVectorSize = 1; 2962249423Sdim } 2963249423Sdim 2964249423Sdim assert(MaxVectorSize <= 32 && "Did not expect to pack so many elements" 2965249423Sdim " into one vector!"); 2966249423Sdim 2967249423Sdim unsigned VF = MaxVectorSize; 2968249423Sdim 2969249423Sdim // If we optimize the program for size, avoid creating the tail loop. 2970249423Sdim if (OptForSize) { 2971249423Sdim // If we are unable to calculate the trip count then don't try to vectorize. 2972249423Sdim if (TC < 2) { 2973249423Sdim DEBUG(dbgs() << "LV: Aborting. A tail loop is required in Os.\n"); 2974249423Sdim return Factor; 2975249423Sdim } 2976249423Sdim 2977249423Sdim // Find the maximum SIMD width that can fit within the trip count. 2978249423Sdim VF = TC % MaxVectorSize; 2979249423Sdim 2980249423Sdim if (VF == 0) 2981249423Sdim VF = MaxVectorSize; 2982249423Sdim 2983249423Sdim // If the trip count that we found modulo the vectorization factor is not 2984249423Sdim // zero then we require a tail. 2985249423Sdim if (VF < 2) { 2986249423Sdim DEBUG(dbgs() << "LV: Aborting. A tail loop is required in Os.\n"); 2987249423Sdim return Factor; 2988249423Sdim } 2989249423Sdim } 2990249423Sdim 2991249423Sdim if (UserVF != 0) { 2992249423Sdim assert(isPowerOf2_32(UserVF) && "VF needs to be a power of two"); 2993249423Sdim DEBUG(dbgs() << "LV: Using user VF "<<UserVF<<".\n"); 2994249423Sdim 2995249423Sdim Factor.Width = UserVF; 2996249423Sdim return Factor; 2997249423Sdim } 2998249423Sdim 2999243789Sdim float Cost = expectedCost(1); 3000243789Sdim unsigned Width = 1; 3001243789Sdim DEBUG(dbgs() << "LV: Scalar loop costs: "<< (int)Cost << ".\n"); 3002243789Sdim for (unsigned i=2; i <= VF; i*=2) { 3003243789Sdim // Notice that the vector loop needs to be executed less times, so 3004243789Sdim // we need to divide the cost of the vector loops by the width of 3005243789Sdim // the vector elements. 3006243789Sdim float VectorCost = expectedCost(i) / (float)i; 3007243789Sdim DEBUG(dbgs() << "LV: Vector loop of width "<< i << " costs: " << 3008243789Sdim (int)VectorCost << ".\n"); 3009243789Sdim if (VectorCost < Cost) { 3010243789Sdim Cost = VectorCost; 3011243789Sdim Width = i; 3012243789Sdim } 3013243789Sdim } 3014243789Sdim 3015243789Sdim DEBUG(dbgs() << "LV: Selecting VF = : "<< Width << ".\n"); 3016249423Sdim Factor.Width = Width; 3017249423Sdim Factor.Cost = Width * Cost; 3018249423Sdim return Factor; 3019243789Sdim} 3020243789Sdim 3021249423Sdimunsigned LoopVectorizationCostModel::getWidestType() { 3022249423Sdim unsigned MaxWidth = 8; 3023249423Sdim 3024249423Sdim // For each block. 3025249423Sdim for (Loop::block_iterator bb = TheLoop->block_begin(), 3026249423Sdim be = TheLoop->block_end(); bb != be; ++bb) { 3027249423Sdim BasicBlock *BB = *bb; 3028249423Sdim 3029249423Sdim // For each instruction in the loop. 3030249423Sdim for (BasicBlock::iterator it = BB->begin(), e = BB->end(); it != e; ++it) { 3031249423Sdim Type *T = it->getType(); 3032249423Sdim 3033249423Sdim // Only examine Loads, Stores and PHINodes. 3034249423Sdim if (!isa<LoadInst>(it) && !isa<StoreInst>(it) && !isa<PHINode>(it)) 3035249423Sdim continue; 3036249423Sdim 3037249423Sdim // Examine PHI nodes that are reduction variables. 3038249423Sdim if (PHINode *PN = dyn_cast<PHINode>(it)) 3039249423Sdim if (!Legal->getReductionVars()->count(PN)) 3040249423Sdim continue; 3041249423Sdim 3042249423Sdim // Examine the stored values. 3043249423Sdim if (StoreInst *ST = dyn_cast<StoreInst>(it)) 3044249423Sdim T = ST->getValueOperand()->getType(); 3045249423Sdim 3046249423Sdim // Ignore loaded pointer types and stored pointer types that are not 3047249423Sdim // consecutive. However, we do want to take consecutive stores/loads of 3048249423Sdim // pointer vectors into account. 3049249423Sdim if (T->isPointerTy() && !isConsecutiveLoadOrStore(it)) 3050249423Sdim continue; 3051249423Sdim 3052249423Sdim MaxWidth = std::max(MaxWidth, 3053249423Sdim (unsigned)DL->getTypeSizeInBits(T->getScalarType())); 3054249423Sdim } 3055249423Sdim } 3056249423Sdim 3057249423Sdim return MaxWidth; 3058249423Sdim} 3059249423Sdim 3060249423Sdimunsigned 3061249423SdimLoopVectorizationCostModel::selectUnrollFactor(bool OptForSize, 3062249423Sdim unsigned UserUF, 3063249423Sdim unsigned VF, 3064249423Sdim unsigned LoopCost) { 3065249423Sdim 3066249423Sdim // -- The unroll heuristics -- 3067249423Sdim // We unroll the loop in order to expose ILP and reduce the loop overhead. 3068249423Sdim // There are many micro-architectural considerations that we can't predict 3069249423Sdim // at this level. For example frontend pressure (on decode or fetch) due to 3070249423Sdim // code size, or the number and capabilities of the execution ports. 3071249423Sdim // 3072249423Sdim // We use the following heuristics to select the unroll factor: 3073249423Sdim // 1. If the code has reductions the we unroll in order to break the cross 3074249423Sdim // iteration dependency. 3075249423Sdim // 2. If the loop is really small then we unroll in order to reduce the loop 3076249423Sdim // overhead. 3077249423Sdim // 3. We don't unroll if we think that we will spill registers to memory due 3078249423Sdim // to the increased register pressure. 3079249423Sdim 3080249423Sdim // Use the user preference, unless 'auto' is selected. 3081249423Sdim if (UserUF != 0) 3082249423Sdim return UserUF; 3083249423Sdim 3084249423Sdim // When we optimize for size we don't unroll. 3085249423Sdim if (OptForSize) 3086249423Sdim return 1; 3087249423Sdim 3088249423Sdim // Do not unroll loops with a relatively small trip count. 3089249423Sdim unsigned TC = SE->getSmallConstantTripCount(TheLoop, 3090249423Sdim TheLoop->getLoopLatch()); 3091249423Sdim if (TC > 1 && TC < TinyTripCountUnrollThreshold) 3092249423Sdim return 1; 3093249423Sdim 3094249423Sdim unsigned TargetVectorRegisters = TTI.getNumberOfRegisters(true); 3095249423Sdim DEBUG(dbgs() << "LV: The target has " << TargetVectorRegisters << 3096249423Sdim " vector registers\n"); 3097249423Sdim 3098249423Sdim LoopVectorizationCostModel::RegisterUsage R = calculateRegisterUsage(); 3099249423Sdim // We divide by these constants so assume that we have at least one 3100249423Sdim // instruction that uses at least one register. 3101249423Sdim R.MaxLocalUsers = std::max(R.MaxLocalUsers, 1U); 3102249423Sdim R.NumInstructions = std::max(R.NumInstructions, 1U); 3103249423Sdim 3104249423Sdim // We calculate the unroll factor using the following formula. 3105249423Sdim // Subtract the number of loop invariants from the number of available 3106249423Sdim // registers. These registers are used by all of the unrolled instances. 3107249423Sdim // Next, divide the remaining registers by the number of registers that is 3108249423Sdim // required by the loop, in order to estimate how many parallel instances 3109249423Sdim // fit without causing spills. 3110249423Sdim unsigned UF = (TargetVectorRegisters - R.LoopInvariantRegs) / R.MaxLocalUsers; 3111249423Sdim 3112249423Sdim // Clamp the unroll factor ranges to reasonable factors. 3113249423Sdim unsigned MaxUnrollSize = TTI.getMaximumUnrollFactor(); 3114249423Sdim 3115249423Sdim // If we did not calculate the cost for VF (because the user selected the VF) 3116249423Sdim // then we calculate the cost of VF here. 3117249423Sdim if (LoopCost == 0) 3118249423Sdim LoopCost = expectedCost(VF); 3119249423Sdim 3120249423Sdim // Clamp the calculated UF to be between the 1 and the max unroll factor 3121249423Sdim // that the target allows. 3122249423Sdim if (UF > MaxUnrollSize) 3123249423Sdim UF = MaxUnrollSize; 3124249423Sdim else if (UF < 1) 3125249423Sdim UF = 1; 3126249423Sdim 3127249423Sdim if (Legal->getReductionVars()->size()) { 3128249423Sdim DEBUG(dbgs() << "LV: Unrolling because of reductions. \n"); 3129249423Sdim return UF; 3130249423Sdim } 3131249423Sdim 3132249423Sdim // We want to unroll tiny loops in order to reduce the loop overhead. 3133249423Sdim // We assume that the cost overhead is 1 and we use the cost model 3134249423Sdim // to estimate the cost of the loop and unroll until the cost of the 3135249423Sdim // loop overhead is about 5% of the cost of the loop. 3136249423Sdim DEBUG(dbgs() << "LV: Loop cost is "<< LoopCost <<" \n"); 3137249423Sdim if (LoopCost < 20) { 3138249423Sdim DEBUG(dbgs() << "LV: Unrolling to reduce branch cost. \n"); 3139249423Sdim unsigned NewUF = 20/LoopCost + 1; 3140249423Sdim return std::min(NewUF, UF); 3141249423Sdim } 3142249423Sdim 3143249423Sdim DEBUG(dbgs() << "LV: Not Unrolling. \n"); 3144249423Sdim return 1; 3145249423Sdim} 3146249423Sdim 3147249423SdimLoopVectorizationCostModel::RegisterUsage 3148249423SdimLoopVectorizationCostModel::calculateRegisterUsage() { 3149249423Sdim // This function calculates the register usage by measuring the highest number 3150249423Sdim // of values that are alive at a single location. Obviously, this is a very 3151249423Sdim // rough estimation. We scan the loop in a topological order in order and 3152249423Sdim // assign a number to each instruction. We use RPO to ensure that defs are 3153249423Sdim // met before their users. We assume that each instruction that has in-loop 3154249423Sdim // users starts an interval. We record every time that an in-loop value is 3155249423Sdim // used, so we have a list of the first and last occurrences of each 3156249423Sdim // instruction. Next, we transpose this data structure into a multi map that 3157249423Sdim // holds the list of intervals that *end* at a specific location. This multi 3158249423Sdim // map allows us to perform a linear search. We scan the instructions linearly 3159249423Sdim // and record each time that a new interval starts, by placing it in a set. 3160249423Sdim // If we find this value in the multi-map then we remove it from the set. 3161249423Sdim // The max register usage is the maximum size of the set. 3162249423Sdim // We also search for instructions that are defined outside the loop, but are 3163249423Sdim // used inside the loop. We need this number separately from the max-interval 3164249423Sdim // usage number because when we unroll, loop-invariant values do not take 3165249423Sdim // more register. 3166249423Sdim LoopBlocksDFS DFS(TheLoop); 3167249423Sdim DFS.perform(LI); 3168249423Sdim 3169249423Sdim RegisterUsage R; 3170249423Sdim R.NumInstructions = 0; 3171249423Sdim 3172249423Sdim // Each 'key' in the map opens a new interval. The values 3173249423Sdim // of the map are the index of the 'last seen' usage of the 3174249423Sdim // instruction that is the key. 3175249423Sdim typedef DenseMap<Instruction*, unsigned> IntervalMap; 3176249423Sdim // Maps instruction to its index. 3177249423Sdim DenseMap<unsigned, Instruction*> IdxToInstr; 3178249423Sdim // Marks the end of each interval. 3179249423Sdim IntervalMap EndPoint; 3180249423Sdim // Saves the list of instruction indices that are used in the loop. 3181249423Sdim SmallSet<Instruction*, 8> Ends; 3182249423Sdim // Saves the list of values that are used in the loop but are 3183249423Sdim // defined outside the loop, such as arguments and constants. 3184249423Sdim SmallPtrSet<Value*, 8> LoopInvariants; 3185249423Sdim 3186249423Sdim unsigned Index = 0; 3187249423Sdim for (LoopBlocksDFS::RPOIterator bb = DFS.beginRPO(), 3188249423Sdim be = DFS.endRPO(); bb != be; ++bb) { 3189249423Sdim R.NumInstructions += (*bb)->size(); 3190249423Sdim for (BasicBlock::iterator it = (*bb)->begin(), e = (*bb)->end(); it != e; 3191249423Sdim ++it) { 3192249423Sdim Instruction *I = it; 3193249423Sdim IdxToInstr[Index++] = I; 3194249423Sdim 3195249423Sdim // Save the end location of each USE. 3196249423Sdim for (unsigned i = 0; i < I->getNumOperands(); ++i) { 3197249423Sdim Value *U = I->getOperand(i); 3198249423Sdim Instruction *Instr = dyn_cast<Instruction>(U); 3199249423Sdim 3200249423Sdim // Ignore non-instruction values such as arguments, constants, etc. 3201249423Sdim if (!Instr) continue; 3202249423Sdim 3203249423Sdim // If this instruction is outside the loop then record it and continue. 3204249423Sdim if (!TheLoop->contains(Instr)) { 3205249423Sdim LoopInvariants.insert(Instr); 3206249423Sdim continue; 3207249423Sdim } 3208249423Sdim 3209249423Sdim // Overwrite previous end points. 3210249423Sdim EndPoint[Instr] = Index; 3211249423Sdim Ends.insert(Instr); 3212249423Sdim } 3213249423Sdim } 3214249423Sdim } 3215249423Sdim 3216249423Sdim // Saves the list of intervals that end with the index in 'key'. 3217249423Sdim typedef SmallVector<Instruction*, 2> InstrList; 3218249423Sdim DenseMap<unsigned, InstrList> TransposeEnds; 3219249423Sdim 3220249423Sdim // Transpose the EndPoints to a list of values that end at each index. 3221249423Sdim for (IntervalMap::iterator it = EndPoint.begin(), e = EndPoint.end(); 3222249423Sdim it != e; ++it) 3223249423Sdim TransposeEnds[it->second].push_back(it->first); 3224249423Sdim 3225249423Sdim SmallSet<Instruction*, 8> OpenIntervals; 3226249423Sdim unsigned MaxUsage = 0; 3227249423Sdim 3228249423Sdim 3229249423Sdim DEBUG(dbgs() << "LV(REG): Calculating max register usage:\n"); 3230249423Sdim for (unsigned int i = 0; i < Index; ++i) { 3231249423Sdim Instruction *I = IdxToInstr[i]; 3232249423Sdim // Ignore instructions that are never used within the loop. 3233249423Sdim if (!Ends.count(I)) continue; 3234249423Sdim 3235249423Sdim // Remove all of the instructions that end at this location. 3236249423Sdim InstrList &List = TransposeEnds[i]; 3237249423Sdim for (unsigned int j=0, e = List.size(); j < e; ++j) 3238249423Sdim OpenIntervals.erase(List[j]); 3239249423Sdim 3240249423Sdim // Count the number of live interals. 3241249423Sdim MaxUsage = std::max(MaxUsage, OpenIntervals.size()); 3242249423Sdim 3243249423Sdim DEBUG(dbgs() << "LV(REG): At #" << i << " Interval # " << 3244249423Sdim OpenIntervals.size() <<"\n"); 3245249423Sdim 3246249423Sdim // Add the current instruction to the list of open intervals. 3247249423Sdim OpenIntervals.insert(I); 3248249423Sdim } 3249249423Sdim 3250249423Sdim unsigned Invariant = LoopInvariants.size(); 3251249423Sdim DEBUG(dbgs() << "LV(REG): Found max usage: " << MaxUsage << " \n"); 3252249423Sdim DEBUG(dbgs() << "LV(REG): Found invariant usage: " << Invariant << " \n"); 3253249423Sdim DEBUG(dbgs() << "LV(REG): LoopSize: " << R.NumInstructions << " \n"); 3254249423Sdim 3255249423Sdim R.LoopInvariantRegs = Invariant; 3256249423Sdim R.MaxLocalUsers = MaxUsage; 3257249423Sdim return R; 3258249423Sdim} 3259249423Sdim 3260243789Sdimunsigned LoopVectorizationCostModel::expectedCost(unsigned VF) { 3261243789Sdim unsigned Cost = 0; 3262243789Sdim 3263249423Sdim // For each block. 3264249423Sdim for (Loop::block_iterator bb = TheLoop->block_begin(), 3265249423Sdim be = TheLoop->block_end(); bb != be; ++bb) { 3266249423Sdim unsigned BlockCost = 0; 3267249423Sdim BasicBlock *BB = *bb; 3268249423Sdim 3269249423Sdim // For each instruction in the old loop. 3270249423Sdim for (BasicBlock::iterator it = BB->begin(), e = BB->end(); it != e; ++it) { 3271249423Sdim // Skip dbg intrinsics. 3272249423Sdim if (isa<DbgInfoIntrinsic>(it)) 3273249423Sdim continue; 3274249423Sdim 3275249423Sdim unsigned C = getInstructionCost(it, VF); 3276249423Sdim Cost += C; 3277249423Sdim DEBUG(dbgs() << "LV: Found an estimated cost of "<< C <<" for VF " << 3278249423Sdim VF << " For instruction: "<< *it << "\n"); 3279249423Sdim } 3280249423Sdim 3281249423Sdim // We assume that if-converted blocks have a 50% chance of being executed. 3282249423Sdim // When the code is scalar then some of the blocks are avoided due to CF. 3283249423Sdim // When the code is vectorized we execute all code paths. 3284249423Sdim if (Legal->blockNeedsPredication(*bb) && VF == 1) 3285249423Sdim BlockCost /= 2; 3286249423Sdim 3287249423Sdim Cost += BlockCost; 3288243789Sdim } 3289243789Sdim 3290243789Sdim return Cost; 3291243789Sdim} 3292243789Sdim 3293243789Sdimunsigned 3294243789SdimLoopVectorizationCostModel::getInstructionCost(Instruction *I, unsigned VF) { 3295243789Sdim // If we know that this instruction will remain uniform, check the cost of 3296243789Sdim // the scalar version. 3297243789Sdim if (Legal->isUniformAfterVectorization(I)) 3298243789Sdim VF = 1; 3299243789Sdim 3300243789Sdim Type *RetTy = I->getType(); 3301243789Sdim Type *VectorTy = ToVectorTy(RetTy, VF); 3302243789Sdim 3303243789Sdim // TODO: We need to estimate the cost of intrinsic calls. 3304243789Sdim switch (I->getOpcode()) { 3305249423Sdim case Instruction::GetElementPtr: 3306249423Sdim // We mark this instruction as zero-cost because the cost of GEPs in 3307249423Sdim // vectorized code depends on whether the corresponding memory instruction 3308249423Sdim // is scalarized or not. Therefore, we handle GEPs with the memory 3309249423Sdim // instruction cost. 3310249423Sdim return 0; 3311249423Sdim case Instruction::Br: { 3312249423Sdim return TTI.getCFInstrCost(I->getOpcode()); 3313249423Sdim } 3314249423Sdim case Instruction::PHI: 3315249423Sdim //TODO: IF-converted IFs become selects. 3316249423Sdim return 0; 3317249423Sdim case Instruction::Add: 3318249423Sdim case Instruction::FAdd: 3319249423Sdim case Instruction::Sub: 3320249423Sdim case Instruction::FSub: 3321249423Sdim case Instruction::Mul: 3322249423Sdim case Instruction::FMul: 3323249423Sdim case Instruction::UDiv: 3324249423Sdim case Instruction::SDiv: 3325249423Sdim case Instruction::FDiv: 3326249423Sdim case Instruction::URem: 3327249423Sdim case Instruction::SRem: 3328249423Sdim case Instruction::FRem: 3329249423Sdim case Instruction::Shl: 3330249423Sdim case Instruction::LShr: 3331249423Sdim case Instruction::AShr: 3332249423Sdim case Instruction::And: 3333249423Sdim case Instruction::Or: 3334249423Sdim case Instruction::Xor: { 3335249423Sdim // Certain instructions can be cheaper to vectorize if they have a constant 3336249423Sdim // second vector operand. One example of this are shifts on x86. 3337249423Sdim TargetTransformInfo::OperandValueKind Op1VK = 3338249423Sdim TargetTransformInfo::OK_AnyValue; 3339249423Sdim TargetTransformInfo::OperandValueKind Op2VK = 3340249423Sdim TargetTransformInfo::OK_AnyValue; 3341243789Sdim 3342249423Sdim if (isa<ConstantInt>(I->getOperand(1))) 3343249423Sdim Op2VK = TargetTransformInfo::OK_UniformConstantValue; 3344243789Sdim 3345249423Sdim return TTI.getArithmeticInstrCost(I->getOpcode(), VectorTy, Op1VK, Op2VK); 3346249423Sdim } 3347249423Sdim case Instruction::Select: { 3348249423Sdim SelectInst *SI = cast<SelectInst>(I); 3349249423Sdim const SCEV *CondSCEV = SE->getSCEV(SI->getCondition()); 3350249423Sdim bool ScalarCond = (SE->isLoopInvariant(CondSCEV, TheLoop)); 3351249423Sdim Type *CondTy = SI->getCondition()->getType(); 3352249423Sdim if (!ScalarCond) 3353249423Sdim CondTy = VectorType::get(CondTy, VF); 3354243789Sdim 3355249423Sdim return TTI.getCmpSelInstrCost(I->getOpcode(), VectorTy, CondTy); 3356249423Sdim } 3357249423Sdim case Instruction::ICmp: 3358249423Sdim case Instruction::FCmp: { 3359249423Sdim Type *ValTy = I->getOperand(0)->getType(); 3360249423Sdim VectorTy = ToVectorTy(ValTy, VF); 3361249423Sdim return TTI.getCmpSelInstrCost(I->getOpcode(), VectorTy); 3362249423Sdim } 3363249423Sdim case Instruction::Store: 3364249423Sdim case Instruction::Load: { 3365249423Sdim StoreInst *SI = dyn_cast<StoreInst>(I); 3366249423Sdim LoadInst *LI = dyn_cast<LoadInst>(I); 3367249423Sdim Type *ValTy = (SI ? SI->getValueOperand()->getType() : 3368249423Sdim LI->getType()); 3369249423Sdim VectorTy = ToVectorTy(ValTy, VF); 3370243789Sdim 3371249423Sdim unsigned Alignment = SI ? SI->getAlignment() : LI->getAlignment(); 3372249423Sdim unsigned AS = SI ? SI->getPointerAddressSpace() : 3373249423Sdim LI->getPointerAddressSpace(); 3374249423Sdim Value *Ptr = SI ? SI->getPointerOperand() : LI->getPointerOperand(); 3375249423Sdim // We add the cost of address computation here instead of with the gep 3376249423Sdim // instruction because only here we know whether the operation is 3377249423Sdim // scalarized. 3378249423Sdim if (VF == 1) 3379249423Sdim return TTI.getAddressComputationCost(VectorTy) + 3380249423Sdim TTI.getMemoryOpCost(I->getOpcode(), VectorTy, Alignment, AS); 3381243789Sdim 3382249423Sdim // Scalarized loads/stores. 3383249423Sdim int Stride = Legal->isConsecutivePtr(Ptr); 3384249423Sdim bool Reverse = Stride < 0; 3385249423Sdim if (0 == Stride) { 3386249423Sdim unsigned Cost = 0; 3387249423Sdim // The cost of extracting from the value vector and pointer vector. 3388249423Sdim Type *PtrTy = ToVectorTy(Ptr->getType(), VF); 3389249423Sdim for (unsigned i = 0; i < VF; ++i) { 3390249423Sdim // The cost of extracting the pointer operand. 3391249423Sdim Cost += TTI.getVectorInstrCost(Instruction::ExtractElement, PtrTy, i); 3392249423Sdim // In case of STORE, the cost of ExtractElement from the vector. 3393249423Sdim // In case of LOAD, the cost of InsertElement into the returned 3394249423Sdim // vector. 3395249423Sdim Cost += TTI.getVectorInstrCost(SI ? Instruction::ExtractElement : 3396249423Sdim Instruction::InsertElement, 3397249423Sdim VectorTy, i); 3398243789Sdim } 3399243789Sdim 3400249423Sdim // The cost of the scalar loads/stores. 3401249423Sdim Cost += VF * TTI.getAddressComputationCost(ValTy->getScalarType()); 3402249423Sdim Cost += VF * TTI.getMemoryOpCost(I->getOpcode(), ValTy->getScalarType(), 3403249423Sdim Alignment, AS); 3404249423Sdim return Cost; 3405243789Sdim } 3406243789Sdim 3407249423Sdim // Wide load/stores. 3408249423Sdim unsigned Cost = TTI.getAddressComputationCost(VectorTy); 3409249423Sdim Cost += TTI.getMemoryOpCost(I->getOpcode(), VectorTy, Alignment, AS); 3410243789Sdim 3411249423Sdim if (Reverse) 3412249423Sdim Cost += TTI.getShuffleCost(TargetTransformInfo::SK_Reverse, 3413249423Sdim VectorTy, 0); 3414249423Sdim return Cost; 3415249423Sdim } 3416249423Sdim case Instruction::ZExt: 3417249423Sdim case Instruction::SExt: 3418249423Sdim case Instruction::FPToUI: 3419249423Sdim case Instruction::FPToSI: 3420249423Sdim case Instruction::FPExt: 3421249423Sdim case Instruction::PtrToInt: 3422249423Sdim case Instruction::IntToPtr: 3423249423Sdim case Instruction::SIToFP: 3424249423Sdim case Instruction::UIToFP: 3425249423Sdim case Instruction::Trunc: 3426249423Sdim case Instruction::FPTrunc: 3427249423Sdim case Instruction::BitCast: { 3428249423Sdim // We optimize the truncation of induction variable. 3429249423Sdim // The cost of these is the same as the scalar operation. 3430249423Sdim if (I->getOpcode() == Instruction::Trunc && 3431249423Sdim Legal->isInductionVariable(I->getOperand(0))) 3432249423Sdim return TTI.getCastInstrCost(I->getOpcode(), I->getType(), 3433249423Sdim I->getOperand(0)->getType()); 3434243789Sdim 3435249423Sdim Type *SrcVecTy = ToVectorTy(I->getOperand(0)->getType(), VF); 3436249423Sdim return TTI.getCastInstrCost(I->getOpcode(), VectorTy, SrcVecTy); 3437249423Sdim } 3438249423Sdim case Instruction::Call: { 3439249423Sdim CallInst *CI = cast<CallInst>(I); 3440249423Sdim Intrinsic::ID ID = getIntrinsicIDForCall(CI, TLI); 3441249423Sdim assert(ID && "Not an intrinsic call!"); 3442249423Sdim Type *RetTy = ToVectorTy(CI->getType(), VF); 3443249423Sdim SmallVector<Type*, 4> Tys; 3444249423Sdim for (unsigned i = 0, ie = CI->getNumArgOperands(); i != ie; ++i) 3445249423Sdim Tys.push_back(ToVectorTy(CI->getArgOperand(i)->getType(), VF)); 3446249423Sdim return TTI.getIntrinsicInstrCost(ID, RetTy, Tys); 3447249423Sdim } 3448249423Sdim default: { 3449249423Sdim // We are scalarizing the instruction. Return the cost of the scalar 3450249423Sdim // instruction, plus the cost of insert and extract into vector 3451249423Sdim // elements, times the vector width. 3452249423Sdim unsigned Cost = 0; 3453243789Sdim 3454249423Sdim if (!RetTy->isVoidTy() && VF != 1) { 3455249423Sdim unsigned InsCost = TTI.getVectorInstrCost(Instruction::InsertElement, 3456249423Sdim VectorTy); 3457249423Sdim unsigned ExtCost = TTI.getVectorInstrCost(Instruction::ExtractElement, 3458249423Sdim VectorTy); 3459249423Sdim 3460243789Sdim // The cost of inserting the results plus extracting each one of the 3461243789Sdim // operands. 3462243789Sdim Cost += VF * (InsCost + ExtCost * I->getNumOperands()); 3463249423Sdim } 3464243789Sdim 3465249423Sdim // The cost of executing VF copies of the scalar instruction. This opcode 3466249423Sdim // is unknown. Assume that it is the same as 'mul'. 3467249423Sdim Cost += VF * TTI.getArithmeticInstrCost(Instruction::Mul, VectorTy); 3468249423Sdim return Cost; 3469249423Sdim } 3470243789Sdim }// end of switch. 3471243789Sdim} 3472243789Sdim 3473243789SdimType* LoopVectorizationCostModel::ToVectorTy(Type *Scalar, unsigned VF) { 3474243789Sdim if (Scalar->isVoidTy() || VF == 1) 3475243789Sdim return Scalar; 3476243789Sdim return VectorType::get(Scalar, VF); 3477243789Sdim} 3478243789Sdim 3479243789Sdimchar LoopVectorize::ID = 0; 3480243789Sdimstatic const char lv_name[] = "Loop Vectorization"; 3481243789SdimINITIALIZE_PASS_BEGIN(LoopVectorize, LV_NAME, lv_name, false, false) 3482243789SdimINITIALIZE_AG_DEPENDENCY(AliasAnalysis) 3483249423SdimINITIALIZE_AG_DEPENDENCY(TargetTransformInfo) 3484243789SdimINITIALIZE_PASS_DEPENDENCY(ScalarEvolution) 3485243789SdimINITIALIZE_PASS_DEPENDENCY(LoopSimplify) 3486243789SdimINITIALIZE_PASS_END(LoopVectorize, LV_NAME, lv_name, false, false) 3487243789Sdim 3488243789Sdimnamespace llvm { 3489243789Sdim Pass *createLoopVectorizePass() { 3490243789Sdim return new LoopVectorize(); 3491243789Sdim } 3492243789Sdim} 3493243789Sdim 3494249423Sdimbool LoopVectorizationCostModel::isConsecutiveLoadOrStore(Instruction *Inst) { 3495249423Sdim // Check for a store. 3496249423Sdim if (StoreInst *ST = dyn_cast<StoreInst>(Inst)) 3497249423Sdim return Legal->isConsecutivePtr(ST->getPointerOperand()) != 0; 3498249423Sdim 3499249423Sdim // Check for a load. 3500249423Sdim if (LoadInst *LI = dyn_cast<LoadInst>(Inst)) 3501249423Sdim return Legal->isConsecutivePtr(LI->getPointerOperand()) != 0; 3502249423Sdim 3503249423Sdim return false; 3504249423Sdim} 3505