Foo analysis for testing the data flow analysis does not support the region without any block. Although that analysis is assumed to be used for testing purpose, it is generally better to be explicit about the scope the framework supports.
The original issue was reported here.
https://github.com/llvm/llvm-project/issues/60580
Reviewed By: springerm
Differential Revision: https://reviews.llvm.org/D144359
Currently, for sparse analyses, we always store a `Optional<ValueT>` in each lattice element. When it's `None`, we consider the lattice element as `uninitialized`.
However:
* Not all lattices have an `uninitialized` state. For example, `Executable` and `PredecessorState` have default values so they are always initialized.
* In dense analyses, we don't have the concept of an `uninitialized` state.
Given these inconsistencies, this patch removes `Lattice::isUninitialized()`. Individual analysis states are now default-constructed. If the default state of an analysis can be considered as "uninitialized" then this analysis should implement the following logic:
* Special join rule: `join(uninitialized, any) == any`.
* Special bail out logic: if any of the input states is uninitialized, exit the transfer function early.
Depends On D132086
Reviewed By: Mogball
Differential Revision: https://reviews.llvm.org/D132800
Depends On D131660
`defaultInitialize()` was introduced for the "nudging" behavior, which has been deleted.
Reviewed By: Mogball, rriddle
Differential Revision: https://reviews.llvm.org/D131746
Removes one element of the pointer union to make it work on 32-bit
systems.
This patch introduces a generic data-flow analysis framework to MLIR. The framework implements a fixed-point iteration algorithm and a dependency graph between lattice states and analysis. Lattice states and points are fully extensible to support highly-customizable analyses.
Reviewed By: phisiart, rriddle
Differential Revision: https://reviews.llvm.org/D126751
This patch introduces a generic data-flow analysis framework to MLIR. The framework implements a fixed-point iteration algorithm and a dependency graph between lattice states and analysis. Lattice states and points are fully extensible to support highly-customizable analyses.
Reviewed By: phisiart, rriddle
Differential Revision: https://reviews.llvm.org/D126751
