This tutorial gives an introduction to the `mlir-opt` tool, focusing on
how to run basic passes with and without options, run pass pipelines
from the CLI, and point out particularly useful flags.
---------
Co-authored-by: Jeremy Kun <j2kun@users.noreply.github.com>
Co-authored-by: Mehdi Amini <joker.eph@gmail.com>
References to headings need to be preceded with a slash. Also,
references to headings on the same page do not need to contain the name
of the document (omitting the document name means if the name changes
the links will still be valid).
I double checked the links by building [the
website](https://github.com/llvm/mlir-www):
```shell
./mlir-www-helper.sh --install-docs ../llvm-project website
cd website && hugo serve
```
Transform interfaces are implemented, direction or via extensions, in
libraries belonging to multiple other dialects. Those dialects don't
need to depend on the non-interface part of the transform dialect, which
includes the growing number of ops and transitive dependency footprint.
Split out the interfaces into a separate library. This in turn requires
flipping the dependency from the interface on the dialect that has crept
in because both co-existed in one library. The interface shouldn't
depend on the transform dialect either.
As a consequence of splitting, the capability of the interpreter to
automatically walk the payload IR to identify payload ops of a certain
kind based on the type used for the entry point symbol argument is
disabled. This is a good move by itself as it simplifies the interpreter
logic. This functionality can be trivially replaced by a
`transform.structured.match` operation.
- Fixed OpenACC's spec link format
- Add missed `OpenACCPasses.md` into Passes.md
- Add missed `MyExtensionCh4.md` into Ch4.md of tutorial of transform
It seems the `Traits.md` file was turned into `Traits/_index.md` in
https://reviews.llvm.org/D153291, causing links to `Traits.md` to no
longer work (instead, `Traits` needs to be used).
Use the "main" transform-interpreter pass instead of the test pass.
This, along with the previously introduced debug extension, now allow
tutorials to no longer depend on test passes and extensions.
Introduce a new extension for simple print-debugging of the transform
dialect scripts. The initial version of this extension consists of two
ops that are printing the payload objects associated with transform
dialect values. Similar ops were already available in the test extenion
and several downstream projects, and were extensively used for testing.
Replace (in tests and docs):
%forall, %tiled = transform.structured.tile_using_forall
with (updated order of return handles):
%tiled, %forall = transform.structured.tile_using_forall
Similar change is applied to (in the TD tutorial):
transform.structured.fuse_into_containing_op
This update makes sure that the tests/documentation are consistent with
the Op specifications. Follow-up for #67320 which updated the order of
the return handles for `tile_using_forall`.
MLIR can't really be const-correct (it would need a `ConstValue` class
alongside the `Value` class really, like `ArrayRef` and
`MutableArrayRef`). This is however making is more consistent: method
that are directly modifying the Value shouldn't be marked const.
Buffer deallocation pipeline previously was incorrect when applied to
functions. It has since been fixed. Make sure it is exercised in the
tutorial to avoid leaking allocations.
Rename and restructure tiling-related transform ops from the structured
extension to be more homogeneous. In particular, all ops now follow a
consistent naming scheme:
- `transform.structured.tile_using_for`;
- `transform.structured.tile_using_forall`;
- `transform.structured.tile_reduction_using_for`;
- `transform.structured.tile_reduction_using_forall`.
This drops the "_op" naming artifact from `tile_to_forall_op` that
shouldn't have been included in the first place, consistently specifies
the name of the control flow op to be produced for loops (instead of
`tile_reduction_using_scf` since `scf.forall` also belongs to `scf`),
and opts for the `using` connector to avoid ambiguity.
The loops produced by tiling are now systematically placed as *trailing*
results of the transform op. While this required changing 3 out of 4 ops
(except for `tile_using_for`), this is the only choice that makes sense
when producing multiple `scf.for` ops that can be associated with a
variadic number of handles. This choice is also most consistent with
*other* transform ops from the structured extension, in particular with
fusion ops, that produce the structured op as the leading result and the
loop as the trailing result.
This chapter demonstrates how one can replicate Halide DSL
transformations using transform dialect operations transforming payload
expressed using Linalg. This was a part of the live tutorial presented
at EuroLLVM 2023.
Functions are always callable operations and thus every operation
implementing the `FunctionOpInterface` also implements the
`CallableOpInterface`. The only exception was the FuncOp in the toy
example. To make implementation of the `FunctionOpInterface` easier,
this commit lets `FunctionOpInterface` inherit from
`CallableOpInterface` and merges some of their methods. More precisely,
the `CallableOpInterface` has methods to get the argument and result
attributes and a method to get the result types of the callable region.
These methods are always implemented the same way as their analogues in
`FunctionOpInterface` and thus this commit moves all the argument and
result attribute handling methods to the callable interface as well as
the methods to get the argument and result types. The
`FuntionOpInterface` then does not have to declare them as well, but
just inherits them from the `CallableOpInterface`.
Adding the inheritance relation also required to move the
`FunctionOpInterface` from the IR directory to the Interfaces directory
since IR should not depend on Interfaces.
Reviewed By: jpienaar, springerm
Differential Revision: https://reviews.llvm.org/D157988
The snippets had several problems including mismatching argument names,
stray or missing symbols, and missing updates to changes in transform
ops. I also rewrapped those comments in the snippets that I touchted
that exceeded 80 characters.
Reviewed By: ftynse
Differential Revision: https://reviews.llvm.org/D154817
- Fix include paths for Transform Dialect Tutorial
- Add math dialect's pass into Pass.md
- Remove a include path of Quant dialect from Pass.md
Reviewed By: ftynse
Differential Revision: https://reviews.llvm.org/D153944
All `apply` functions now have a `TransformRewriter &` parameter. This rewriter should be used to modify the IR. It has a `TrackingListener` attached and updates the internal handle-payload mappings based on rewrites.
Implementations no longer need to create their own `TrackingListener` and `IRRewriter`. Error checking is integrated into `applyTransform`. Tracking listener errors are reported only for ops with the `ReportTrackingListenerFailuresOpTrait` trait attached, allowing for a gradual migration. Furthermore, errors can be silenced with an op attribute.
Additional API will be added to `TransformRewriter` in subsequent revisions. This revision just adds an "empty" `TransformRewriter` class and updates all `apply` implementations.
Differential Revision: https://reviews.llvm.org/D152427
The call to 'multiply_transpose' in the initialization of the variable 'f' was
intended to have a shape mismatch. However the variable 'a' has shape <2, 3> and
the variable 'c' has shape <3, 2>, so the arguments 'transpose(a)' and 'c' have
in fact compatible shapes (<3, 2> both), the opposite of what is wanted here.
This commit removes the transpose so that arguments 'a' and 'c' have
incompatible shapes <2, 3> and <3, 2>, respectively.
Reviewed By: mehdi_amini
Differential Revision: https://reviews.llvm.org/D151897
The transform dialect has been around for a while and is sufficiently
stable at this point. Add the first three chapters of the tutorial
describing its usage and extension.
Reviewed By: springerm
Differential Revision: https://reviews.llvm.org/D151491
Currently `CallOpInterface` has a method `getCallableForCallee` to have a consistent way to get the callee from an operation with `CallOpInterface`, but missing a consistent way to set a callee for an operation with `CallOpInterface`.
A set callee method is useful for transformations that operate on `CallOpInterface`, and change the callee, e.g., a pass that specialize function, which clone the callee, and change the `CallOpInterface`'s callee to the cloned version. Without such method, transformation would need to understand the implementation for every operations with `CallOpInterface`, and have a type switch to handle them.
This review adds a method to set callee for operation with `CallOpInterface`.
Reviewed By: gysit, zero9178o
Differential Revision: https://reviews.llvm.org/D149763
The revision adds the handleArgument and handleResult handlers that
allow users of the inlining interface to implement argument and result
conversions that take argument and result attributes into account. The
motivating use cases for this revision are taken from the LLVM dialect
inliner, which has to copy arguments that are marked as byval and that
also has to consider zeroext / signext when converting integers.
All type conversions are currently handled by the
materializeCallConversion hook. It runs before isLegalToInline and
supports only the introduction of a single cast operation since it may
have to rollback. The new handlers run shortly before and after
inlining and cannot fail. As a result, they can introduce more complex
ir such as copying a struct argument. At the moment, the new hooks
cannot be used to perform type conversions since all type conversions
have to be done using the materializeCallConversion. A follow up
revision will either relax this constraint or drop
materializeCallConversion in favor of the new and more flexible
handlers.
The revision also extends the CallableOpInterface to provide access
to the argument and result attributes if available.
Reviewed By: rriddle, Dinistro
Differential Revision: https://reviews.llvm.org/D145582
In MLIR tutorial example code, use `Pure` to remove the side-effects of
operations. Update the document to be consistent with the example code.
Reviewed By: mehdi_amini
Differential Revision: https://reviews.llvm.org/D143814
Currently `TypedValue` can be constructed directly from `Value`, hiding
errors that could be caught at compile time. For example the following
will compile, but crash/assert at runtime:
```
void foo(TypedValue<IntegerType>);
void bar(TypedValue<FloatType> v) {
foo(v);
}
```
This change removes the constructors and replaces them with explicit
llvm casts.
Depends on D142852
Reviewed By: rriddle
Differential Revision: https://reviews.llvm.org/D142855
In Toy tutorial chapter 1, multiply_transpose() is called with b<2, 3>
and c<3, 2> when both parameters should have the same shape. This commit
fixes this by instead using c and d as parameters and fix a comment typo
where c and d are mentioned to have shape <2, 2> when they actually have
shape <3, 2>.
Reviewed By: mehdi_amini
Differential Revision: https://reviews.llvm.org/D142622
Currently `PassManager` defaults to being anchored on `builtin.module`.
Switching the default makes `PassManager` consistent with
`OpPassManager` and avoids the implicit dependency on `builtin.module`.
Specifying the anchor op type isn't strictly necessary when using
explicit nesting (existing pipelines will continue to work), but I've
updated most call sites to specify the anchor since it allows for better
error-checking during pipeline construction.
Reviewed By: rriddle
Differential Revision: https://reviews.llvm.org/D137731
The patch adds operations to `BlockAndValueMapping` and renames it to `IRMapping`. When operations are cloned, old operations are mapped to the cloned operations. This allows mapping from an operation to a cloned operation. Example:
```
Operation *opWithRegion = ...
Operation *opInsideRegion = &opWithRegion->front().front();
IRMapping map
Operation *newOpWithRegion = opWithRegion->clone(map);
Operation *newOpInsideRegion = map.lookupOrNull(opInsideRegion);
```
Migration instructions:
All includes to `mlir/IR/BlockAndValueMapping.h` should be replaced with `mlir/IR/IRMapping.h`. All uses of `BlockAndValueMapping` need to be renamed to `IRMapping`.
Reviewed By: rriddle, mehdi_amini
Differential Revision: https://reviews.llvm.org/D139665
This is part of the RFC for a better fold API: https://discourse.llvm.org/t/rfc-a-better-fold-api-using-more-generic-adaptors/67374
This patch implements the required foldHook changes and the TableGen machinery for generating `fold` method signatures using `FoldAdaptor` for ops, based on the value of `useFoldAPI` of the dialect. It may be one of 2 values, with convenient named constants to create a quasi enum. The new `fold` method will then be generated if `kEmitFoldAdaptorFolder` is used.
Since the new `FoldAdaptor` approach is strictly better than the old signature, part of this patch updates the documentation and all example to encourage use of the new `fold` signature.
Included are also tests exercising the new API, ensuring proper construction of the `FoldAdaptor` and proper generation by TableGen.
Differential Revision: https://reviews.llvm.org/D140886
In the Ch6 of the Toy Example for MLIR, there is a broken link. If ones goes to [the page for Chapter 6](https://mlir.llvm.org/docs/Tutorials/Toy/Ch-6/), and click on the link "Conversion to the LLVM IR Dialect", one will see it takes you to a page that no longer exists.
I believe this should actually be [this link](https://mlir.llvm.org/docs/TargetLLVMIR/).
Note to reviewers that this is my first submitted patch to LLVM, and using the phabricator system, so there is a higher risk that I have made an error, and brief feedback on these patch notes would be appreciated.
Reviewer rational: Users who git blame say contributed to the tutorial.
I believe that automated tests on these markdown docs could reduce the risk of this kind of error occurring again. For example, [this Python package](https://pypi.org/project/linkcheckmd/) checks for broken markdown links. However, I am unsure where in the existing testing infrastructure this could go, I am only somewhat familiar with the C++ side.
Reviewed By: Mogball
Differential Revision: https://reviews.llvm.org/D133977
This moves the documentation for defining dialects, attributes/types,
and operations into a new `DefiningDialects` folder. This helps to
keep the documentation grouped together, making it easier to find
related documentation.
Differential Revision: https://reviews.llvm.org/D137594
This patch takes the first step towards a more principled modeling of undefined behavior in MLIR as discussed in the following discourse threads:
1. https://discourse.llvm.org/t/semantics-modeling-undefined-behavior-and-side-effects/4812
2. https://discourse.llvm.org/t/rfc-mark-tensor-dim-and-memref-dim-as-side-effecting/65729
This patch in particular does the following:
1. Introduces a ConditionallySpeculatable OpInterface that dynamically determines whether an Operation can be speculated.
2. Re-defines `NoSideEffect` to allow undefined behavior, making it necessary but not sufficient for speculation. Also renames it to `NoMemoryEffect`.
3. Makes LICM respect the above semantics.
4. Changes all ops tagged with `NoSideEffect` today to additionally implement ConditionallySpeculatable and mark themselves as always speculatable. This combined trait is named `Pure`. This makes this change NFC.
For out of tree dialects:
1. Replace `NoSideEffect` with `Pure` if the operation does not have any memory effects, undefined behavior or infinite loops.
2. Replace `NoSideEffect` with `NoSideEffect` otherwise.
The next steps in this process are (I'm proposing to do these in upcoming patches):
1. Update operations like `tensor.dim`, `memref.dim`, `scf.for`, `affine.for` to implement a correct hook for `ConditionallySpeculatable`. I'm also happy to update ops in other dialects if the respective dialect owners would like to and can give me some pointers.
2. Update other passes that speculate operations to consult `ConditionallySpeculatable` in addition to `NoMemoryEffect`. I could not find any other than LICM on a quick skim, but I could have missed some.
3. Add some documentation / FAQs detailing the differences between side effects, undefined behavior, speculatabilty.
Reviewed By: rriddle, mehdi_amini
Differential Revision: https://reviews.llvm.org/D135505
This patch "modernizes" the LLVM `insertvalue` and `extractvalue`
operations to use DenseI64ArrayAttr, since they only require an array of
indices and previously there was confusion about whether to use i32 or
i64 arrays, and to use assembly format.
Reviewed By: ftynse
Differential Revision: https://reviews.llvm.org/D131537
When converted to the LLVM dialect, the memref.alloc and memref.free operations were generating calls to hardcoded 'malloc' and 'free' functions. This didn't leave any freedom to users to provide their custom implementation. Those operations now convert into calls to '_mlir_alloc' and '_mlir_free' functions, which have also been implemented into the runtime support library as wrappers to 'malloc' and 'free'. The same has been done for the 'aligned_alloc' function.
Reviewed By: ftynse
Differential Revision: https://reviews.llvm.org/D128791
