1 //===- Traits.cpp - Common op traits shared by dialects -------------------===//
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 #include "mlir/Dialect/Traits.h"
10 #include "mlir/IR/BuiltinTypes.h"
11 #include "mlir/IR/TypeUtilities.h"
12 #include "llvm/Support/FormatVariadic.h"
13
14 using namespace mlir;
15
staticallyKnownBroadcastable(ArrayRef<int64_t> shape1,ArrayRef<int64_t> shape2)16 bool OpTrait::util::staticallyKnownBroadcastable(ArrayRef<int64_t> shape1,
17 ArrayRef<int64_t> shape2) {
18 // Two dimensions are compatible when
19 // 1. they are defined and equal, or
20 // 2. one of them is 1
21 return llvm::all_of(llvm::zip(llvm::reverse(shape1), llvm::reverse(shape2)),
22 [](auto dimensions) {
23 auto dim1 = std::get<0>(dimensions);
24 auto dim2 = std::get<1>(dimensions);
25 if (dim1 == 1 || dim2 == 1)
26 return true;
27 if (dim1 == dim2 && !ShapedType::isDynamic(dim1))
28 return true;
29 return false;
30 });
31 }
32
getBroadcastedShape(ArrayRef<int64_t> shape1,ArrayRef<int64_t> shape2,SmallVectorImpl<int64_t> & resultShape)33 bool OpTrait::util::getBroadcastedShape(ArrayRef<int64_t> shape1,
34 ArrayRef<int64_t> shape2,
35 SmallVectorImpl<int64_t> &resultShape) {
36 // To compute the result broadcasted shape, we compare operand shapes
37 // element-wise: starting with the trailing dimensions, and working the
38 // way backward. Two dimensions are compatible when
39 // 1. they are equal, or
40 // 2. one of them is 1
41 // The result shape has the maximum among the two inputs at every
42 // dimension index.
43
44 resultShape.clear();
45 if (shape1.size() > shape2.size()) {
46 std::copy(shape1.begin(), shape1.end(), std::back_inserter(resultShape));
47 } else {
48 std::copy(shape2.begin(), shape2.end(), std::back_inserter(resultShape));
49 }
50
51 auto i1 = shape1.rbegin(), e1 = shape1.rend();
52 auto i2 = shape2.rbegin(), e2 = shape2.rend();
53 auto iR = resultShape.rbegin();
54
55 // Check each dimension is consistent.
56 for (; i1 != e1 && i2 != e2; ++i1, ++i2, ++iR) {
57 if (*i1 == -1 || *i2 == -1) {
58 // One or both dimensions is unknown. Follow TensorFlow behavior:
59 // - If either dimension is greater than 1, we assume that the program is
60 // correct, and the other dimension will be broadcast to match it.
61 // - If either dimension is 1, the other dimension is the output.
62 if (*i1 > 1) {
63 *iR = *i1;
64 } else if (*i2 > 1) {
65 *iR = *i2;
66 } else if (*i1 == 1) {
67 *iR = *i2;
68 } else if (*i2 == 1) {
69 *iR = *i1;
70 } else {
71 *iR = -1;
72 }
73 } else {
74 if (*i1 == *i2 || *i2 == 1) {
75 *iR = *i1;
76 } else if (*i1 == 1) {
77 *iR = *i2;
78 } else {
79 // This dimension of the two operand types is incompatible.
80 resultShape.clear();
81 return false;
82 }
83 }
84 }
85
86 return true;
87 }
88
89 /// Returns the shape of the given type. Scalars will be considered as having a
90 /// shape with zero dimensions.
getShape(Type type)91 static ArrayRef<int64_t> getShape(Type type) {
92 if (auto sType = type.dyn_cast<ShapedType>())
93 return sType.getShape();
94 return {};
95 }
96
97 /// Returns the result broadcast composition type from the two given types by
98 /// following NumPy broadcast semantics. Returned type may have dynamic shape if
99 /// either of the input types has dynamic shape. Returns null type if the two
100 /// given types are not broadcast-compatible.
101 ///
102 /// elementType, if specified, will be used as the element type of the
103 /// broadcasted result type. Otherwise it is required that the element type of
104 /// type1 and type2 is the same and this element type will be used as the
105 /// resultant element type.
getBroadcastedType(Type type1,Type type2,Type elementType)106 Type OpTrait::util::getBroadcastedType(Type type1, Type type2,
107 Type elementType) {
108 // If the elementType is not specified, then the use the common element type
109 // of the inputs or fail if there is no common element type.
110 if (!elementType) {
111 elementType = getElementTypeOrSelf(type1);
112 if (elementType != getElementTypeOrSelf(type2))
113 return {};
114 }
115
116 // If one of the types is unranked tensor, then the other type shouldn't be
117 // vector and the result should have unranked tensor type.
118 if (type1.isa<UnrankedTensorType>() || type2.isa<UnrankedTensorType>()) {
119 if (type1.isa<VectorType>() || type2.isa<VectorType>())
120 return {};
121 return UnrankedTensorType::get(elementType);
122 }
123
124 // Returns the type kind if the given type is a vector or ranked tensor type.
125 // Returns llvm::None otherwise.
126 auto getCompositeTypeKind = [](Type type) -> Optional<TypeID> {
127 if (type.isa<VectorType, RankedTensorType>())
128 return type.getTypeID();
129 return llvm::None;
130 };
131
132 // Make sure the composite type, if has, is consistent.
133 Optional<TypeID> compositeKind1 = getCompositeTypeKind(type1);
134 Optional<TypeID> compositeKind2 = getCompositeTypeKind(type2);
135 Optional<TypeID> resultCompositeKind;
136
137 if (compositeKind1 && compositeKind2) {
138 // Disallow mixing vector and tensor.
139 if (compositeKind1 != compositeKind2)
140 return {};
141 resultCompositeKind = compositeKind1;
142 } else if (compositeKind1) {
143 resultCompositeKind = compositeKind1;
144 } else if (compositeKind2) {
145 resultCompositeKind = compositeKind2;
146 }
147
148 // Get the shape of each type.
149 SmallVector<int64_t, 4> resultShape;
150 if (!getBroadcastedShape(getShape(type1), getShape(type2), resultShape))
151 return {};
152
153 // Compose the final broadcasted type
154 if (resultCompositeKind == VectorType::getTypeID())
155 return VectorType::get(resultShape, elementType);
156 if (resultCompositeKind == RankedTensorType::getTypeID())
157 return RankedTensorType::get(resultShape, elementType);
158 return elementType;
159 }
160
161 /// Returns a tuple corresponding to whether range has tensor or vector type.
162 template <typename iterator_range>
hasTensorOrVectorType(iterator_range types)163 static std::tuple<bool, bool> hasTensorOrVectorType(iterator_range types) {
164 return std::make_tuple(
165 llvm::any_of(types, [](Type t) { return t.isa<TensorType>(); }),
166 llvm::any_of(types, [](Type t) { return t.isa<VectorType>(); }));
167 }
168
areCompatibleShapes(ArrayRef<int64_t> shape1,ArrayRef<int64_t> shape2)169 static bool areCompatibleShapes(ArrayRef<int64_t> shape1,
170 ArrayRef<int64_t> shape2) {
171 auto isCompatible = [](int64_t dim1, int64_t dim2) {
172 return dim1 == dim2 || dim1 == -1 || dim2 == -1;
173 };
174 if (shape1.size() != shape2.size())
175 return false;
176 for (auto p : llvm::zip(shape1, shape2))
177 if (!isCompatible(std::get<0>(p), std::get<1>(p)))
178 return false;
179 return true;
180 }
181
getShapeString(ArrayRef<int64_t> shape)182 static std::string getShapeString(ArrayRef<int64_t> shape) {
183 // TODO: should replace with printing shape more uniformly across here and
184 // when in type.
185 return std::string(
186 formatv("'{0:$[x]}'", llvm::make_range(shape.begin(), shape.end())));
187 }
188
verifyCompatibleOperandBroadcast(Operation * op)189 LogicalResult OpTrait::impl::verifyCompatibleOperandBroadcast(Operation *op) {
190 // Ensure broadcasting only tensor or only vector types.
191 auto operandsHasTensorVectorType =
192 hasTensorOrVectorType(op->getOperandTypes());
193 auto resultsHasTensorVectorType = hasTensorOrVectorType(op->getResultTypes());
194 if ((std::get<0>(operandsHasTensorVectorType) ||
195 std::get<0>(resultsHasTensorVectorType)) &&
196 (std::get<1>(operandsHasTensorVectorType) ||
197 std::get<1>(resultsHasTensorVectorType)))
198 return op->emitError("cannot broadcast vector with tensor");
199
200 auto rankedOperands = make_filter_range(
201 op->getOperandTypes(), [](Type t) { return t.isa<RankedTensorType>(); });
202
203 // If all operands are unranked, then all result shapes are possible.
204 if (rankedOperands.empty())
205 return success();
206
207 // Compute broadcasted shape of operands (which requires that operands are
208 // broadcast compatible). The results need to be broadcast compatible with
209 // this result shape.
210 SmallVector<int64_t, 4> resultShape;
211 (void)util::getBroadcastedShape(getShape(*rankedOperands.begin()), {},
212 resultShape);
213 for (auto other : make_early_inc_range(rankedOperands)) {
214 SmallVector<int64_t, 4> temp = resultShape;
215 if (!util::getBroadcastedShape(temp, getShape(other), resultShape))
216 return op->emitOpError("operands don't have broadcast-compatible shapes");
217 }
218
219 auto rankedResults = make_filter_range(
220 op->getResultTypes(), [](Type t) { return t.isa<RankedTensorType>(); });
221
222 // If all of the results are unranked then no further verification.
223 if (rankedResults.empty())
224 return success();
225
226 for (auto type : rankedResults) {
227 ArrayRef<int64_t> actualSuffix =
228 getShape(type).take_back(resultShape.size());
229 if (!areCompatibleShapes(actualSuffix, resultShape))
230 return op->emitOpError()
231 << "result type " << getShapeString(getShape(type))
232 << " not broadcast compatible with broadcasted operands's shapes "
233 << getShapeString(resultShape);
234 }
235 return success();
236 }
237