LLVM  10.0.0svn
SLPVectorizer.h
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1 //===- SLPVectorizer.h ------------------------------------------*- C++ -*-===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 // This pass implements the Bottom Up SLP vectorizer. It detects consecutive
9 // stores that can be put together into vector-stores. Next, it attempts to
10 // construct vectorizable tree using the use-def chains. If a profitable tree
11 // was found, the SLP vectorizer performs vectorization on the tree.
12 //
13 // The pass is inspired by the work described in the paper:
14 // "Loop-Aware SLP in GCC" by Ira Rosen, Dorit Nuzman, Ayal Zaks.
15 //
16 //===----------------------------------------------------------------------===//
17 
18 #ifndef LLVM_TRANSFORMS_VECTORIZE_SLPVECTORIZER_H
19 #define LLVM_TRANSFORMS_VECTORIZE_SLPVECTORIZER_H
20 
21 #include "llvm/ADT/ArrayRef.h"
22 #include "llvm/ADT/MapVector.h"
23 #include "llvm/ADT/None.h"
24 #include "llvm/ADT/SmallVector.h"
26 #include "llvm/IR/PassManager.h"
27 
28 namespace llvm {
29 
30 class AssumptionCache;
31 class BasicBlock;
32 class CmpInst;
33 class DataLayout;
34 class DemandedBits;
35 class DominatorTree;
36 class Function;
37 class InsertElementInst;
38 class InsertValueInst;
39 class Instruction;
40 class LoopInfo;
41 class OptimizationRemarkEmitter;
42 class PHINode;
43 class ScalarEvolution;
44 class StoreInst;
45 class TargetLibraryInfo;
46 class TargetTransformInfo;
47 class Value;
48 
49 /// A private "module" namespace for types and utilities used by this pass.
50 /// These are implementation details and should not be used by clients.
51 namespace slpvectorizer {
52 
53 class BoUpSLP;
54 
55 } // end namespace slpvectorizer
56 
58 
59 struct SLPVectorizerPass : public PassInfoMixin<SLPVectorizerPass> {
64 
65  ScalarEvolution *SE = nullptr;
66  TargetTransformInfo *TTI = nullptr;
67  TargetLibraryInfo *TLI = nullptr;
68  AliasAnalysis *AA = nullptr;
69  LoopInfo *LI = nullptr;
70  DominatorTree *DT = nullptr;
71  AssumptionCache *AC = nullptr;
72  DemandedBits *DB = nullptr;
73  const DataLayout *DL = nullptr;
74 
75 public:
77 
78  // Glue for old PM.
80  TargetLibraryInfo *TLI_, AliasAnalysis *AA_, LoopInfo *LI_,
83 
84 private:
85  /// Collect store and getelementptr instructions and organize them
86  /// according to the underlying object of their pointer operands. We sort the
87  /// instructions by their underlying objects to reduce the cost of
88  /// consecutive access queries.
89  ///
90  /// TODO: We can further reduce this cost if we flush the chain creation
91  /// every time we run into a memory barrier.
92  void collectSeedInstructions(BasicBlock *BB);
93 
94  /// Try to vectorize a chain that starts at two arithmetic instrs.
95  bool tryToVectorizePair(Value *A, Value *B, slpvectorizer::BoUpSLP &R);
96 
97  /// Try to vectorize a list of operands.
98  /// \param UserCost Cost of the user operations of \p VL if they may affect
99  /// the cost of the vectorization.
100  /// \returns true if a value was vectorized.
101  bool tryToVectorizeList(ArrayRef<Value *> VL, slpvectorizer::BoUpSLP &R,
102  int UserCost = 0, bool AllowReorder = false);
103 
104  /// Try to vectorize a chain that may start at the operands of \p I.
105  bool tryToVectorize(Instruction *I, slpvectorizer::BoUpSLP &R);
106 
107  /// Vectorize the store instructions collected in Stores.
108  bool vectorizeStoreChains(slpvectorizer::BoUpSLP &R);
109 
110  /// Vectorize the index computations of the getelementptr instructions
111  /// collected in GEPs.
112  bool vectorizeGEPIndices(BasicBlock *BB, slpvectorizer::BoUpSLP &R);
113 
114  /// Try to find horizontal reduction or otherwise vectorize a chain of binary
115  /// operators.
116  bool vectorizeRootInstruction(PHINode *P, Value *V, BasicBlock *BB,
118  TargetTransformInfo *TTI);
119 
120  /// Try to vectorize trees that start at insertvalue instructions.
121  bool vectorizeInsertValueInst(InsertValueInst *IVI, BasicBlock *BB,
123 
124  /// Try to vectorize trees that start at insertelement instructions.
125  bool vectorizeInsertElementInst(InsertElementInst *IEI, BasicBlock *BB,
127 
128  /// Try to vectorize trees that start at compare instructions.
129  bool vectorizeCmpInst(CmpInst *CI, BasicBlock *BB, slpvectorizer::BoUpSLP &R);
130 
131  /// Tries to vectorize constructs started from CmpInst, InsertValueInst or
132  /// InsertElementInst instructions.
133  bool vectorizeSimpleInstructions(SmallVectorImpl<Instruction *> &Instructions,
135 
136  /// Scan the basic block and look for patterns that are likely to start
137  /// a vectorization chain.
138  bool vectorizeChainsInBlock(BasicBlock *BB, slpvectorizer::BoUpSLP &R);
139 
140  bool vectorizeStoreChain(ArrayRef<Value *> Chain, slpvectorizer::BoUpSLP &R,
141  unsigned VecRegSize);
142 
143  bool vectorizeStores(ArrayRef<StoreInst *> Stores, slpvectorizer::BoUpSLP &R);
144 
145  /// The store instructions in a basic block organized by base pointer.
146  StoreListMap Stores;
147 
148  /// The getelementptr instructions in a basic block organized by base pointer.
149  GEPListMap GEPs;
150 };
151 
152 } // end namespace llvm
153 
154 #endif // LLVM_TRANSFORMS_VECTORIZE_SLPVECTORIZER_H
A parsed version of the target data layout string in and methods for querying it. ...
Definition: DataLayout.h:111
This class is the base class for the comparison instructions.
Definition: InstrTypes.h:722
static bool runImpl(Function &F, TargetLibraryInfo &TLI, DominatorTree &DT)
This is the entry point for all transforms.
This class represents lattice values for constants.
Definition: AllocatorList.h:23
Various leaf nodes.
Definition: ISDOpcodes.h:59
The main scalar evolution driver.
A cache of @llvm.assume calls within a function.
F(f)
This class consists of common code factored out of the SmallVector class to reduce code duplication b...
Definition: APFloat.h:41
A CRTP mix-in to automatically provide informational APIs needed for passes.
Definition: PassManager.h:373
ArrayRef - Represent a constant reference to an array (0 or more elements consecutively in memory)...
Definition: APInt.h:32
Concrete subclass of DominatorTreeBase that is used to compute a normal dominator tree...
Definition: Dominators.h:144
cl::opt< bool > RunSLPVectorization
#define P(N)
This instruction inserts a single (scalar) element into a VectorType value.
static GCRegistry::Add< OcamlGC > B("ocaml", "ocaml 3.10-compatible GC")
A set of analyses that are preserved following a run of a transformation pass.
Definition: PassManager.h:154
LLVM Basic Block Representation.
Definition: BasicBlock.h:57
This pass provides access to the codegen interfaces that are needed for IR-level transformations.
This is a &#39;vector&#39; (really, a variable-sized array), optimized for the case when the array is small...
Definition: SmallVector.h:837
Provides information about what library functions are available for the current target.
#define I(x, y, z)
Definition: MD5.cpp:58
LLVM Value Representation.
Definition: Value.h:74
A container for analyses that lazily runs them and caches their results.
This header defines various interfaces for pass management in LLVM.
Bottom Up SLP Vectorizer.
The optimization diagnostic interface.
This instruction inserts a struct field of array element value into an aggregate value.