It's recommended practice that people calling MLIR in a loop
pre-create a LLVM ThreadPool and a dialect registry and then
explicitly pass those into a MLIRContext for each compilation.
However, the C API does not expose the functions needed to follow this
recommendation from a project that isn't calling MLIR's C++ dilectly.
Add the necessary APIs to mlir-c, including a wrapper around LLVM's
ThreadPool struct (so as to avoid having to amend or re-export parts
of the LLVM API).
Reviewed By: makslevental
Differential Revision: https://reviews.llvm.org/D153593
depends on D150839
This diff uses `MlirTypeID` to register `TypeCaster`s (i.e., `[](PyType pyType) -> DerivedTy { return pyType; }`) for all concrete types (i.e., `PyConcrete<...>`) that are then queried for (by `MlirTypeID`) and called in `struct type_caster<MlirType>::cast`. The result is that anywhere an `MlirType mlirType` is returned from a python binding, that `mlirType` is automatically cast to the correct concrete type. For example:
```
c0 = arith.ConstantOp(f32, 0.0)
# CHECK: F32Type(f32)
print(repr(c0.result.type))
unranked_tensor_type = UnrankedTensorType.get(f32)
unranked_tensor = tensor.FromElementsOp(unranked_tensor_type, [c0]).result
# CHECK: UnrankedTensorType
print(type(unranked_tensor.type).__name__)
# CHECK: UnrankedTensorType(tensor<*xf32>)
print(repr(unranked_tensor.type))
```
This functionality immediately extends to typed attributes (i.e., `attr.type`).
The diff also implements similar functionality for `mlir_type_subclass`es but in a slightly different way - for such types (which have no cpp corresponding `class` or `struct`) the user must provide a type caster in python (similar to how `AttrBuilder` works) or in cpp as a `py::cpp_function`.
Reviewed By: ftynse
Differential Revision: https://reviews.llvm.org/D150927
Adds the ability to create external passes using the C-API. This allows passes
to be written in C or languages that use the C-bindings.
Differential Revision: https://reviews.llvm.org/D121866
Symbol tables are a largely useful top-level IR construct, for example, they
make it easy to access functions in a module by name instead of traversing the
list of module's operations to find the corresponding function.
Depends On D112886
Reviewed By: mehdi_amini
Differential Revision: https://reviews.llvm.org/D112821
Numerous MLIR functions return instances of `StringRef` to refer to a
non-owning fragment of a string (usually owned by the context). This is a
relatively simple class that is defined in LLVM. Provide a simple wrapper in
the MLIR C API that contains the pointer and length of the string fragment and
use it for Standard attribute functions that return StringRef instead of the
previous, callback-based mechanism.
Reviewed By: stellaraccident
Differential Revision: https://reviews.llvm.org/D87677
