Detailed writeup is in https://github.com/google/heir/issues/1153. See
also https://github.com/llvm/llvm-project/pull/120881. In short,
`propagateIfChanged` is used outside of the `DataFlowAnalysis` scope,
because it is public, but it does not propagate as expected as the
`DataFlowSolver` has stopped running.
To solve such misuse, `propagateIfChanged` should be made
protected/private.
For downstream users affected by this, to correctly propagate the
change, the Analysis should be re-run (check #120881) instead of just a
`propagateIfChanged`
The change to `IntegerRangeAnalysis` is just a expansion of the
`solver->propagateIfChanged`. The `Lattice` has already been updated by
the `join`. Propagation is done by `onUpdate`.
Cc @Mogball for review
Note that PointerUnion::{is,get} have been soft deprecated in
PointerUnion.h:
// FIXME: Replace the uses of is(), get() and dyn_cast() with
// isa<T>, cast<T> and the llvm::dyn_cast<T>
I'm not touching PointerUnion::dyn_cast for now because it's a bit
complicated; we could blindly migrate it to dyn_cast_if_present, but
we should probably use dyn_cast when the operand is known to be
non-null.
The concept of a 'program point' in the original data flow framework is
ambiguous. It can refer to either an operation or a block itself. This
representation has different interpretations in forward and backward
data-flow analysis. In forward data-flow analysis, the program point of
an operation represents the state after the operation, while in backward
data flow analysis, it represents the state before the operation. When
using forward or backward data-flow analysis, it is crucial to carefully
handle this distinction to ensure correctness.
This patch refactors the definition of program point, unifying the
interpretation of program points in both forward and backward data-flow
analysis.
How to integrate this patch?
For dense forward data-flow analysis and other analysis (except dense
backward data-flow analysis), the program point corresponding to the
original operation can be obtained by `getProgramPointAfter(op)`, and
the program point corresponding to the original block can be obtained by
`getProgramPointBefore(block)`.
For dense backward data-flow analysis, the program point corresponding
to the original operation can be obtained by
`getProgramPointBefore(op)`, and the program point corresponding to the
original block can be obtained by `getProgramPointAfter(block)`.
NOTE: If you need to get the lattice of other data-flow analyses in
dense backward data-flow analysis, you should still use the dense
forward data-flow approach. For example, to get the Executable state of
a block in dense backward data-flow analysis and add the dependency of
the current operation, you should write:
``getOrCreateFor<Executable>(getProgramPointBefore(op),
getProgramPointBefore(block))``
In case above, we use getProgramPointBefore(op) because the analysis we
rely on is dense backward data-flow, and we use
getProgramPointBefore(block) because the lattice we query is the result
of a non-dense backward data flow computation.
related dsscussion:
https://discourse.llvm.org/t/rfc-unify-the-semantics-of-program-points/80671/8
corresponding PSA:
https://discourse.llvm.org/t/psa-program-point-semantics-change/81479
This patch distinguishes between program points and lattice anchors in
data flow analysis, where lattice anchors represent locations where a
lattice can be attached, while program points denote points in program
execution.
Related discussions:
https://discourse.llvm.org/t/rfc-unify-the-semantics-of-program-points/80671/8
This is the counterpart to the forward dense dataflow analysis and
integrates into the dataflow framework. The implementation follows the
structure of existing dataflow analyses.
Reviewed By: Mogball, phisiart
Differential Revision: https://reviews.llvm.org/D154713
In the MLIR dataflow analysis framework, when an `AnalysisState` is updated, it's dependents are enqueued to be visited.
Currently, there are two ways dependents are managed:
* `AnalysisState::dependents` stores a list of dependents. `DataFlowSolver::propagateIfChanged()` reads this list and enqueues them to the worklist.
* `AnalysisState::onUpdate()` allows custom logic to enqueue more to the worklist. This is called by `DataFlowSolver::propagateIfChanged()`.
This cleanup diff consolidates the two into `AnalysisState::onUpdate()`. This way, `DataFlowSolver` does not need to know the detail about `AnalysisState::dependents`, and the logic of dependency management is entirely handled by `AnalysisState`.
Reviewed By: Mogball
Differential Revision: https://reviews.llvm.org/D154170
The MLIR classes Type/Attribute/Operation/Op/Value support
cast/dyn_cast/isa/dyn_cast_or_null functionality through llvm's doCast
functionality in addition to defining methods with the same name.
This change begins the migration of uses of the method to the
corresponding function call as has been decided as more consistent.
Note that there still exist classes that only define methods directly,
such as AffineExpr, and this does not include work currently to support
a functional cast/isa call.
Context:
- https://mlir.llvm.org/deprecation/ at "Use the free function variants
for dyn_cast/cast/isa/…"
- Original discussion at https://discourse.llvm.org/t/preferred-casting-style-going-forward/68443
Implementation:
This patch updates all remaining uses of the deprecated functionality in
mlir/. This was done with clang-tidy as described below and further
modifications to GPUBase.td and OpenMPOpsInterfaces.td.
Steps are described per line, as comments are removed by git:
0. Retrieve the change from the following to build clang-tidy with an
additional check:
main...tpopp:llvm-project:tidy-cast-check
1. Build clang-tidy
2. Run clang-tidy over your entire codebase while disabling all checks
and enabling the one relevant one. Run on all header files also.
3. Delete .inc files that were also modified, so the next build rebuilds
them to a pure state.
```
ninja -C $BUILD_DIR clang-tidy
run-clang-tidy -clang-tidy-binary=$BUILD_DIR/bin/clang-tidy -checks='-*,misc-cast-functions'\
-header-filter=mlir/ mlir/* -fix
rm -rf $BUILD_DIR/tools/mlir/**/*.inc
```
Differential Revision: https://reviews.llvm.org/D151542
Integer range inference has been swapped to the new framework. The integer value range lattices automatically updates the corresponding constant value on update.
Depends on D127173
Reviewed By: krzysz00, rriddle
Differential Revision: https://reviews.llvm.org/D128866
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
