MLIR  17.0.0git
IntegerSet.h
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1 //===- IntegerSet.h - MLIR Integer Set Class --------------------*- C++ -*-===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // Integer sets are sets of points from the integer lattice constrained by
10 // affine equality/inequality constraints. This class is meant to represent
11 // integer sets in the IR - for 'affine.if' operations and as attributes of
12 // other operations. It is typically expected to contain only a handful of
13 // affine constraints, and is immutable like an affine map. Integer sets are not
14 // unique'd unless the number of constraints they contain are below a certain
15 // threshold - although affine expressions that make up its equalities and
16 // inequalities are themselves unique.
17 
18 // This class is not meant for affine analysis and operations like set
19 // operations, emptiness checks, or other math operations for analysis and
20 // transformation. For the latter, use FlatAffineConstraints.
21 //
22 //===----------------------------------------------------------------------===//
23 
24 #ifndef MLIR_IR_INTEGERSET_H
25 #define MLIR_IR_INTEGERSET_H
26 
27 #include "mlir/IR/AffineExpr.h"
28 #include "llvm/ADT/ArrayRef.h"
29 
30 namespace mlir {
31 
32 namespace detail {
33 struct IntegerSetStorage;
34 } // namespace detail
35 
36 class MLIRContext;
37 
38 /// An integer set representing a conjunction of one or more affine equalities
39 /// and inequalities. An integer set in the IR is immutable like the affine map,
40 /// but integer sets are not unique'd unless the number of constraints in them
41 /// is below `kUniquingThreshold`. The affine expressions that make up the
42 /// equalities and inequalities of an integer set are themselves unique and are
43 /// allocated by the bump pointer allocator.
44 class IntegerSet {
45 public:
47 
48  constexpr IntegerSet() = default;
49  explicit IntegerSet(ImplType *set) : set(set) {}
50 
51  static IntegerSet get(unsigned dimCount, unsigned symbolCount,
52  ArrayRef<AffineExpr> constraints,
53  ArrayRef<bool> eqFlags);
54 
55  // Returns the canonical empty IntegerSet (i.e. a set with no integer points).
56  static IntegerSet getEmptySet(unsigned numDims, unsigned numSymbols,
57  MLIRContext *context) {
58  auto one = getAffineConstantExpr(1, context);
59  // 1 == 0.
60  return get(numDims, numSymbols, one, true);
61  }
62 
63  /// Returns true if this is the canonical integer set.
64  bool isEmptyIntegerSet() const;
65 
66  /// This method substitutes any uses of dimensions and symbols (e.g.
67  /// dim#0 with dimReplacements[0]) in subexpressions and returns the modified
68  /// integer set. Because this can be used to eliminate dims and
69  /// symbols, the client needs to specify the number of dims and symbols in
70  /// the result. The returned map always has the same number of results.
72  ArrayRef<AffineExpr> symReplacements,
73  unsigned numResultDims,
74  unsigned numResultSyms);
75 
76  explicit operator bool() { return set; }
77  bool operator==(IntegerSet other) const { return set == other.set; }
78  bool operator!=(IntegerSet other) const { return set != other.set; }
79 
80  unsigned getNumDims() const;
81  unsigned getNumSymbols() const;
82  unsigned getNumInputs() const;
83  unsigned getNumConstraints() const;
84  unsigned getNumEqualities() const;
85  unsigned getNumInequalities() const;
86 
88 
89  AffineExpr getConstraint(unsigned idx) const;
90 
91  /// Returns the equality bits, which specify whether each of the constraints
92  /// is an equality or inequality.
93  ArrayRef<bool> getEqFlags() const;
94 
95  /// Returns true if the idx^th constraint is an equality, false if it is an
96  /// inequality.
97  bool isEq(unsigned idx) const;
98 
99  MLIRContext *getContext() const;
100 
101  /// Walk all of the AffineExpr's in this set's constraints. Each node in an
102  /// expression tree is visited in postorder.
103  void walkExprs(function_ref<void(AffineExpr)> callback) const;
104 
105  void print(raw_ostream &os) const;
106  void dump() const;
107 
108  friend ::llvm::hash_code hash_value(IntegerSet arg);
109 
110  /// Methods supporting C API.
111  const void *getAsOpaquePointer() const {
112  return static_cast<const void *>(set);
113  }
114  static IntegerSet getFromOpaquePointer(const void *pointer) {
115  return IntegerSet(
116  reinterpret_cast<ImplType *>(const_cast<void *>(pointer)));
117  }
118 
119 private:
120  ImplType *set{nullptr};
121 };
122 
123 // Make AffineExpr hashable.
124 inline ::llvm::hash_code hash_value(IntegerSet arg) {
125  return ::llvm::hash_value(arg.set);
126 }
127 
128 } // namespace mlir
129 namespace llvm {
130 
131 // IntegerSet hash just like pointers.
132 template <>
133 struct DenseMapInfo<mlir::IntegerSet> {
135  auto *pointer = llvm::DenseMapInfo<void *>::getEmptyKey();
136  return mlir::IntegerSet(static_cast<mlir::IntegerSet::ImplType *>(pointer));
137  }
140  return mlir::IntegerSet(static_cast<mlir::IntegerSet::ImplType *>(pointer));
141  }
142  static unsigned getHashValue(mlir::IntegerSet val) {
143  return mlir::hash_value(val);
144  }
145  static bool isEqual(mlir::IntegerSet LHS, mlir::IntegerSet RHS) {
146  return LHS == RHS;
147  }
148 };
149 
150 } // namespace llvm
151 #endif // MLIR_IR_INTEGERSET_H
Base type for affine expression.
Definition: AffineExpr.h:68
An integer set representing a conjunction of one or more affine equalities and inequalities.
Definition: IntegerSet.h:44
detail::IntegerSetStorage ImplType
Definition: IntegerSet.h:46
void walkExprs(function_ref< void(AffineExpr)> callback) const
Walk all of the AffineExpr's in this set's constraints.
Definition: IntegerSet.cpp:63
IntegerSet replaceDimsAndSymbols(ArrayRef< AffineExpr > dimReplacements, ArrayRef< AffineExpr > symReplacements, unsigned numResultDims, unsigned numResultSyms)
This method substitutes any uses of dimensions and symbols (e.g.
Definition: IntegerSet.cpp:68
constexpr IntegerSet()=default
unsigned getNumDims() const
Definition: IntegerSet.cpp:15
static IntegerSet get(unsigned dimCount, unsigned symbolCount, ArrayRef< AffineExpr > constraints, ArrayRef< bool > eqFlags)
void dump() const
MLIRContext * getContext() const
Definition: IntegerSet.cpp:57
unsigned getNumInputs() const
Definition: IntegerSet.cpp:17
bool operator==(IntegerSet other) const
Definition: IntegerSet.h:77
unsigned getNumConstraints() const
Definition: IntegerSet.cpp:21
static IntegerSet getEmptySet(unsigned numDims, unsigned numSymbols, MLIRContext *context)
Definition: IntegerSet.h:56
friend ::llvm::hash_code hash_value(IntegerSet arg)
Definition: IntegerSet.h:124
ArrayRef< AffineExpr > getConstraints() const
Definition: IntegerSet.cpp:41
bool operator!=(IntegerSet other) const
Definition: IntegerSet.h:78
unsigned getNumEqualities() const
Definition: IntegerSet.cpp:25
bool isEmptyIntegerSet() const
Returns true if this is the canonical integer set.
Definition: IntegerSet.cpp:37
static IntegerSet getFromOpaquePointer(const void *pointer)
Definition: IntegerSet.h:114
const void * getAsOpaquePointer() const
Methods supporting C API.
Definition: IntegerSet.h:111
AffineExpr getConstraint(unsigned idx) const
Definition: IntegerSet.cpp:45
void print(raw_ostream &os) const
IntegerSet(ImplType *set)
Definition: IntegerSet.h:49
unsigned getNumInequalities() const
Definition: IntegerSet.cpp:33
bool isEq(unsigned idx) const
Returns true if the idx^th constraint is an equality, false if it is an inequality.
Definition: IntegerSet.cpp:55
ArrayRef< bool > getEqFlags() const
Returns the equality bits, which specify whether each of the constraints is an equality or inequality...
Definition: IntegerSet.cpp:51
unsigned getNumSymbols() const
Definition: IntegerSet.cpp:16
MLIRContext is the top-level object for a collection of MLIR operations.
Definition: MLIRContext.h:56
Include the generated interface declarations.
Definition: CallGraph.h:229
Include the generated interface declarations.
inline ::llvm::hash_code hash_value(IntegerSet arg)
Definition: IntegerSet.h:124
AffineExpr getAffineConstantExpr(int64_t constant, MLIRContext *context)
Definition: AffineExpr.cpp:527
inline ::llvm::hash_code hash_value(AffineExpr arg)
Make AffineExpr hashable.
Definition: AffineExpr.h:240
static bool isEqual(mlir::IntegerSet LHS, mlir::IntegerSet RHS)
Definition: IntegerSet.h:145
static unsigned getHashValue(mlir::IntegerSet val)
Definition: IntegerSet.h:142
static mlir::IntegerSet getEmptyKey()
Definition: IntegerSet.h:134
static mlir::IntegerSet getTombstoneKey()
Definition: IntegerSet.h:138