forked from OSchip/llvm-project
44e9869f1a
MLIR has support for type-polymorphic instructions, i.e. instructions that may take arguments of different types. For example, standard arithmetic operands take scalars, vectors or tensors. In order to express such instructions in TableGen, we need to be able to verify that a type object satisfies certain constraints, but we don't need to construct an instance of this type. The existing TableGen definition of Type requires both. Extract out a TypeConstraint TableGen class to define restrictions on types. Define the Type TableGen class as a subclass of TypeConstraint for consistency. Accept records of the TypeConstraint class instead of the Type class as values in the Arguments class when defining operators. Replace the predicate logic TableGen class based on conjunctive normal form with the predicate logic classes allowing for abitrary combinations of predicates using Boolean operators (AND/OR/NOT). The combination is implemented using simple string rewriting of C++ expressions and, therefore, respects the short-circuit evaluation order. No logic simplification is performed at the TableGen level so all expressions must be valid C++. Maintaining CNF using TableGen only would have been complicated when one needed to introduce top-level disjunction. It is also unclear if it could lead to a significantly simpler emitted C++ code. In the future, we may replace inplace predicate string combination with a tree structure that can be simplified in TableGen's C++ driver. Combined, these changes allow one to express traits like ArgumentsAreFloatLike directly in TableGen instead of relying on C++ trait classes. PiperOrigin-RevId: 229398247 |
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| .. | ||
| Attribute.cpp | ||
| Operator.cpp | ||
| Predicate.cpp | ||
| Type.cpp | ||