A dialect can opt-in to handle versioning through the
`BytecodeDialectInterface`. Few hooks are exposed to the dialect to allow
managing a version encoded into the bytecode file. The version is loaded
lazily and allows to retrieve the version information while parsing the input
IR, and gives an opportunity to each dialect for which a version is present
to perform IR upgrades post-parsing through the `upgradeFromVersion` method.
Custom Attribute and Type encodings can also be upgraded according to the
dialect version using readAttribute and readType methods.
There is no restriction on what kind of information a dialect is allowed to
encode to model its versioning. Currently, versioning is supported only for
bytecode formats.
Reviewed By: rriddle, mehdi_amini
Differential Revision: https://reviews.llvm.org/D143647
Resources are encoded in two separate sections similarly to
attributes/types, one for the actual data and one for the data
offsets. Unlike other sections, the resource sections are optional
given that in many cases they won't be present. For testing,
bytecode serialization is added for DenseResourceElementsAttr.
Differential Revision: https://reviews.llvm.org/D132729
This commit adds a new bytecode serialization format for MLIR.
The actual serialization of MLIR to binary is relatively straightforward,
given the very very general structure of MLIR. The underlying basis for
this format is a variable-length encoding for integers, which gets heavily
used for nearly all aspects of the encoding (given that most of the encoding
is just indexing into lists).
The format currently does not provide support for custom attribute/type
serialization, and thus always uses an assembly format fallback. It also
doesn't provide support for resources. These will be added in followups,
the intention for this patch is to provide something that supports the
basic cases, and can be built on top of.
https://discourse.llvm.org/t/rfc-a-binary-serialization-format-for-mlir/63518
Differential Revision: https://reviews.llvm.org/D131747
