This PR adds "downcasting" of `ir.Value` to either `BlockArgument` or
`OpResult` (and then potentially further down if a user-registered
"value caster" exists). Also this PR changes `__str__` to return the
correct thing (`OpResult(...)` or `BlockArgument(...)` instead of
generic `Value(...)`).
We've been able to do `isinstance(x, Type)` for a quite a while now
(since
bfb1ba7526)
so remove `Type.isinstance` and the the special-casing
(`_is_integer_type`, `_is_floating_point_type`, `_is_index_type`) in
some places (and therefore support various `fp8`, `fp6`, `fp4` types).
This PR ports all in-tree dialect extensions to use the
`PyConcreteType`, `PyConcreteAttribute` CRTPs instead of
`mlir_pure_subclass`. After this PR we can soft deprecate
`mlir_pure_subclass`. Also API signatures are updated to use `Py*`
instead of `Mlir*` so that type "inference" and hints are improved.
# What
This PR adds a shared library `MLIRPythonSupport` which contains all of
the CRTP classes ike `PyConcreteValue`, `PyConcreteType`,
`PyConcreteAttribute`, as well as other useful code like `Defaulting*`
and etc enabling their reuse in downstream projects. Downstream projects
can now do
```c++
struct PyTestType : mlir::python::MLIR_BINDINGS_PYTHON_DOMAIN::PyConcreteType<PyTestType> {
...
};
class PyTestAttr : public mlir::python::MLIR_BINDINGS_PYTHON_DOMAIN::PyConcreteAttribute<PyTestAttr> {
...
}
NB_MODULE(_mlirPythonTestNanobind, m) {
PyTestType::bind(m);
PyTestAttr::bind(m);
}
```
instead of using the discordant alternative
`mlir_type_subclass`/`mlir_attr_subclass` (same goes for
`PyConcreteValue`/`mlir_value_subclass`).
# Why
This PR is mostly code motion (along with CMake) but before I describe
the changes I want to state the goals/benefits:
1. Currently upstream "core" extensions and "dialect" extensions ([all
of the `Dialect*` extensions
here](d7c734b5a1/mlir/lib/Bindings/Python))
are a two-tier system;
**a**. [core
extensions](https://github.com/llvm/llvm-project/blob/main/mlir/lib/Bindings/Python/IRTypes.cpp#L361)
enjoy first class support as far as type inference[^3], type stub
generation, and ease of implementation, while dialect extensions [have
poorer support](https://reviews.llvm.org/D150927), incorrect type stub
generation much more tedious (boilerplate) implementation;
**b**. Crucially, this two-tiered system is reflected in the fact that
**the two sets of types/attributes are not in the same Python object
hierarchy**. To wit: `isinstance(..., Type)` and `isinstance(...,
Attribute)` are not supported for the dialect extensions[^2];
**c**. Since these types are not exposed in public headers, downstream
users (dialect extensions or not) cannot write functions that overload
on e.g. `PyFloat8*Type` - that's quite a [useful
feature](fdbee98df8/cpp_ext/TorchOps.cpp (L29-L69))!
2. The dialect extensions incur a sizeable performance penalty relative
to the core extensions in that every single trip across the wire (either
`python->cpp` or `cpp->python`) requires work in addition to nanobind's
own casting/construction pipeline;
**a**. When going from `python->cpp`, [we extract the capsule object
from the Python
object](https://github.com/llvm/llvm-project/blob/main/mlir/include/mlir/Bindings/Python/NanobindAdaptors.h#L219C24-L219C46)
and then extract from the capsule the `Mlir*` opaque struct/ptr. This
side isn't so onerous;
**b**. When going from `cpp->python` we call long-hand call Python
`import` APIs and construct the Python object using `_CAPICreate`. Note,
there at least 2 `attr` calls incurred in addition to `_CAPICreate`;
this is already much more [efficiently handled by nanobind
itself](4ba51fcf79/src/nb_internals.h (L381-L382))!
3. This division blocks various features: in some configurations[^1] we
trigger a circular import bug because "dialect" types and attributes
perform an [import of the root `_mlir`
module](bd9651bf78/mlir/include/mlir/Bindings/Python/NanobindAdaptors.h (L585))
when they are created (the types themselves, not even instances of those
types). This blocks type stub generation for dialect extensions (i.e.,
the reason we currently only generate type stubs for `_mlir`).
# How
Prior this was not done/possible because of "ODR" issues but I have
resolved those issues; the basic idea for how we solve this is "move
things we want to share into shared libraries":
1. Move IRCore (stuff like `PyConcreteValue`, `PyConcreteType`,
`PyConcreteAttribute`) into `MLIRPythonSupport`;
- Note, we move the rest of the things in `IRModule.h` (renamed to
`IRCore.h`) because `PyConcreteValue`, `PyConcreteType`,
`PyConcreteAttribute` depend on them. This makes for a bigger PR than
one would hope for but ultimately I think we should give people access
to these classes to use as they see fit (specifically inherit from, but
also liberally use in bindings signatures instead of the opaque `Mlir*`
struct wrappers).
2. Put all of this code into a nested namespace
`MLIR_BINDINGS_PYTHON_DOMAIN` which is determined by a compile time
define (and tied to `MLIR_BINDINGS_PYTHON_NB_DOMAIN`). This is necessary
in order to prevent conflicts on both symbol name **and** typeid
(necessary for nanobind to not double register binded types) between
multiple bindings libraries (e.g., `torch-mlir`, and `jax`). Note
[nanobind doesn't support `module_local` like
pybind11](https://nanobind.readthedocs.io/en/latest/porting.html#removed-features).
It does support `NB_DOMAIN` but that is not sufficient for
disambiguating typeids across projects (to wit: we currently define
`NB_DOMAIN` and it was still necessary to move everything to a nested
namespace);
3. Build the [nanobind library itself as a shared
object](https://github.com/wjakob/nanobind/blob/master/cmake/nanobind-config.cmake#L127)
(and link it to both the extensions and `MLIRPythonSupport`).
4. CMake to make this work, in-tree, out-of-tree, downstream, upstream,
etc.
# Testing
Three tests are added here
1. `PythonTestModuleNanobind` is ported to use
`PyConcreteType<PyTestType>` instead of `mlir_type_subclass` and
`PyConcreteAttribute<PyTestAttr>` instead of `mlir_atrr_subclass`,
verifying this works for non-core extensions in-tree;
2. `StandaloneExtensionNanobind` is ported to use `struct PyCustomType :
mlir::python::MLIR_BINDINGS_PYTHON_DOMAIN::PyConcreteType<PyCustomType>`
instead of `mlir_type_subclass` verifying this works for non-core
extensions out-of-tree;
3. `StandaloneExtensionNanobind`'s `smoketest` is extended to also load
another bindings package (namely `mlir`) verifying
`MLIR_BINDINGS_PYTHON_DOMAIN` successfully disambiguates symbols and
typeids.
I have also tested this downstream:
https://github.com/llvm/eudsl/pull/287 as well run the following builder
bots:
mlir-nvidia-gcc7:
https://lab.llvm.org/buildbot/#/buildrequests/6654424?redirect_to_build=true
I have also tested against IREE:
https://github.com/iree-org/iree/pull/21916
# Integration
It is highly recommended to set the CMake var
`MLIR_BINDINGS_PYTHON_NB_DOMAIN` (which will also determine
`MLIR_BINDINGS_PYTHON_DOMAIN`) to something unique for each downstream.
This can also be passed explicitly to `add_mlir_python_modules` if your
project builds multiple bindings packages. I added a `WARNING` to this
effect in `AddMLIRPython.cmake`.
[^3]: Python values being typed correctly when exiting from cpp;
[^1]: Specifically when the modules are imported using `importlib`,
which occurs with nanobind's
[stubgen](https://github.com/wjakob/nanobind/blob/master/src/stubgen.py#L965);
[^2]: The workaround we implemented was a class method for the dialect
bindings called `Class.isinstance(...)`;
Fixes: #164800
Ensures unsigned pooling ops in Linalg stay in the integer domain: the
lowering now rejects floating/bool inputs with a clear diagnostic, new
regression tests lock in both the error path and a valid integer
example, and transform decompositions are updated to reflect the integer
typing.
Signed-off-by: Akimasa Watanuki <mencotton0410@gmail.com>
This is a follow-up of #171957 that updates the argument names of
`scf.if` Python binding to be consistent with `affine.if`. Basically,
both operations should use `has_else` to determine whether the `if`
block is presented.
cc @makslevental
Friendlier wrapper for transform.foreach.
To facilitate that friendliness, makes it so that OpResult.owner returns
the relevant OpView instead of Operation. For good measure, also changes
Value.owner to return OpView instead of Operation, thereby ensuring
consistency. That is, makes it is so that all op-returning .owner
accessors return OpView (and thereby give access to all goodies
available on registered OpViews.)
Reland of #171544 due to fixup for integration test.
Friendlier wrapper for `transform.foreach`.
To facilitate that friendliness, makes it so that `OpResult.owner`
returns the relevant `OpView` instead of `Operation`. For good measure,
also changes `Value.owner` to return `OpView` instead of `Operation`,
thereby ensuring consistency. That is, makes it is so that all
op-returning `.owner` accessors return `OpView` (and thereby give access
to all goodies available on registered `OpView`s.)
This bug was introduced by #108323, where the loc and ip were not
properly set. It may lead to errors when the operations are not linearly
asserted to the IR.
Following a series of refactorings, MLIR Python bindings would crash if
a
dialect object requiring a context defined using
mlir_attribute/type_subclass
was constructed outside of the `ir.Context` context manager. The type
caster
for `MlirContext` would try using `ir.Context.current` when the default
`None`
value was provided to the `get`, which would also just return `None`.
The
caster would then attempt to obtain the MLIR capsule for that `None`,
fail,
but access it anyway without checking, leading to a C++ assertion
failure or
segfault.
Guard against this case in nanobind adaptors. Also emit a warning to the
user
to clarify expectations, as the default message confusingly says that
`None` is
accepted as context and then fails with a type error. Using Python C API
is
currently recommended by nanobind in this case since the surrounding
function
must be marked `noexcept`.
The corresponding test is in the PDL dialect since it is where I first
observed
the behavior. Core types are not using the `mlir_type_subclass`
mechanism and
are immune to the problem, so cannot be used for checking.
The current implementation of the WMMA intrinsic ops as they are defined
in the ROCDL tablegen is incorrect. They represent as operands what
should be attributes such as `clamp`, `opsel`, `signA/signB`. This
change performs a refactoring to bring it in line with what we expect.
---------
Signed-off-by: Muzammiluddin Syed <muzasyed@amd.com>
This makes it similar to `mlir::TypedValue` in the MLIR C++ API and
allows users to be more specific about the values they produce or
accept.
Co-authored-by: Maksim Levental <maksim.levental@gmail.com>
This PR exposes `linalg::inferContractionDims(ArrayRef<AffineMap>)` to
Python, allowing users to infer contraction dimensions (batch/m/n/k)
directly from a list of affine maps without needing an operation.
---------
Signed-off-by: Bangtian Liu <liubangtian@gmail.com>
The C++ index switch op has utilities for `getCaseBlock(int i)` and
`getDefaultBlock()`, so these have been added.
Optional body builder args have been added: one for the default case and
one for the switch cases.
Updates the derived Op-classes for the main transform ops to have all
the arguments, etc, from the auto-generated classes. Additionally
updates and adds missing snake_case wrappers for the derived classes
which shadow the snake_case wrappers of the auto-generated classes,
which were hitherto exposed alongside the derived classes.
Adds the first XeGPU transform op, `xegpu.set_desc_layout`, which attachs a `xegpu.layout` attribute to the descriptor that a `xegpu.create_nd_tdesc` op returns.
Add builders on the Python side that match builders in the C++ side, add tests for launching GPU kernels and regions, and correct some small documentation mistakes. This reflects the API decisions already made in the func dialect's Python bindings and makes use of the GPU dialect's bindings work more similar to C++ interface.
By allowing `transform.smt.constrain_params`'s region to yield SMT-vars,
op instances can declare relationships, through constraints, on incoming
params-as-SMT-vars and outgoing SMT-vars-as-params. This makes it
possible to declare that computations on params should be performed.
The semantics are that the yielded SMT-vars should be from any valid
satisfying assignment/model of the constraints in the region.
This test passed locally because I had a python environment with the
`python` command available, but I should have used the `%PYTHON` lit
command substitution instead. Fixes buildbot failures from #163620.
Adds initial support for Python bindings to the OpenACC dialect.
* The bindings do not provide any niceties yet, just the barebones
exposure of the dialect to Python. Construction of OpenACC ops is
therefore verbose and somewhat inconvenient, as evidenced by the test.
* The test only constructs one module, but I attempted to use enough
operations to be meaningful. It does not test all the ops exposed, but
does contain a realistic example of a memcpy idiom.
The func dialect provides a more pythonic interface for constructing
operations, but the gpu dialect does not; this is the first PR to
provide the same conveniences for the gpu dialect, starting with the
gpu.func op.
Changes to linalg `structured.fuse` transform op:
* Adds an optional `use_forall` boolean argument which generates a tiled
`scf.forall` loop instead of `scf.for` loops.
* `tile_sizes` can now be any parameter or handle.
* `tile_interchange` can now be any parameter or handle.
* IR formatting changes from `transform.structured.fuse %0 [4, 8] ...`
to `transform.structured.fuse %0 tile_sizes [4, 8] ...`
- boolean arguments are now `UnitAttrs` and should be set via the op
attr-dict: `{apply_cleanup, use_forall}`
This op enables expressing uncertainty regarding what should be
happening at particular places in transform-dialect schedules. In
particular, it enables representing a choice among alternative regions.
This choice is resolved through providing a `selected_region` argument.
When this argument is provided, the semantics are such that it is valid
to rewrite the op through substituting in the selected region -- with
the op's interpreted semantics corresponding to exactly this.
This op represents another piece of the puzzle w.r.t. a toolkit for
expressing autotuning problems with the transform dialect. Note that
this goes beyond tuning knobs _on_ transforms, going further by making
it tunable which (sequences of) transforms are to be applied.
This is a follow-up to https://github.com/llvm/llvm-project/pull/144307,
where we removed `vector.matrix_multiply` and `vector.flat_transpose`
from the Vector dialect.
This PR:
* Updates comments that were missed in the previous change.
* Renames relevant `-convert-vector-to-llvm=` options:
- `vector-contract-lowering=matmul` → `vector-contract-lowering=llvmintr`
- `vector-transpose-lowering=flat_transpose` → `vector-transpose-lowering=llvmintr`
These new names better reflect the actual transformation target - LLVM
intrinsics - rather than the now-removed abstract operations.
Introduces a Transform-dialect SMT-extension so that we can have an op
to express constrains on Transform-dialect params, in particular when
these params are knobs -- see transform.tune.knob -- and can hence be
seen as symbolic variables. This op allows expressing joint constraints
over multiple params/knobs together.
While the op's semantics are clearly defined, per SMTLIB, the interpreted
semantics -- i.e. the `apply()` method -- for now just defaults to failure. In
the future we should support attaching an implementation so that users
can Bring Your Own Solver and thereby control performance of
interpreting the op. For now the main usage is to walk schedule IR and
collect these constraints so that knobs can be rewritten to constants that
satisfy the constraints.
In this PR we add basic python bindings for IRDL dialect, so that python
users can create and load IRDL dialects in python. This allows users, to
some extent, to define dialects in Python without having to modify
MLIR’s CMake/TableGen/C++ code and rebuild, making prototyping more
convenient.
A basic example is shown below (and also in the added test case):
```python
# create a module with IRDL dialects
module = Module.create()
with InsertionPoint(module.body):
dialect = irdl.DialectOp("irdl_test")
with InsertionPoint(dialect.body):
op = irdl.OperationOp("test_op")
with InsertionPoint(op.body):
f32 = irdl.is_(TypeAttr.get(F32Type.get()))
irdl.operands_([f32], ["input"], [irdl.Variadicity.single])
# load the module
irdl.load_dialects(module)
# use the op defined in IRDL
m = Module.parse("""
module {
%a = arith.constant 1.0 : f32
"irdl_test.test_op"(%a) : (f32) -> ()
}
""")
```
