Commit Graph

96 Commits

Author SHA1 Message Date
Matthias Springer
6aaa8f25b6 [mlir][IR][NFC] Move free-standing functions to MemRefType (#123465)
Turn free-standing `MemRefType`-related helper functions in
`BuiltinTypes.h` into member functions.
2025-01-21 08:48:09 +01:00
Kazu Hirata
fecf1397e3 [Tensor] Migrate away from PointerUnion::{is,get} (NFC) (#120679)
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.
2024-12-20 10:41:54 -08:00
Christopher Bate
ced2fc7819 [mlir][bufferization] Fix OneShotBufferize when defaultMemorySpaceFn is used (#91524)
As described in issue llvm/llvm-project#91518, a previous PR
llvm/llvm-project#78484 introduced the `defaultMemorySpaceFn` into
bufferization options, allowing one to inform OneShotBufferize that it
should use a specified function to derive the memory space attribute
from the encoding attribute attached to tensor types.

However, introducing this feature exposed unhandled edge cases,
examples of which are introduced by this change in the new test under

`test/Dialect/Bufferization/Transforms/one-shot-bufferize-encodings.mlir`.

Fixing the inconsistencies introduced by `defaultMemorySpaceFn` is
pretty simple. This change:

- Updates the `bufferization.to_memref` and `bufferization.to_tensor`
  operations to explicitly include operand and destination types,
  whereas previously they relied on type inference to deduce the
  tensor types. Since the type inference cannot recover the correct
  tensor encoding/memory space, the operand and result types must be
  explicitly included. This is a small assembly format change, but it
  touches a large number of test files.

- Makes minor updates to other bufferization functions to handle the
  changes in building the above ops.

- Updates bufferization of `tensor.from_elements` to handle memory
  space.


Integration/upgrade guide:

In downstream projects, if you have tests or MLIR files that explicitly
use
`bufferization.to_tensor` or `bufferization.to_memref`, then update
them to the new assembly format as follows:

```
%1 = bufferization.to_memref %0 : memref<10xf32>
%2 = bufferization.to_tensor %1 : memref<10xf32>
```

becomes

```
%1 = bufferization.to_memref %0 : tensor<10xf32> to memref<10xf32>
%2 = bufferization.to_tensor %0 : memref<10xf32> to tensor<10xf32> 
```
2024-11-26 09:45:57 -07:00
Max191
98e838a890 [mlir] Do not bufferize parallel_insert_slice dest to read for full slices (#112761)
In the insert_slice bufferization interface implementation, the
destination tensor is not considered read if the full tensor is
overwritten by the slice. This PR adds the same check for
tensor.parallel_insert_slice.

Adds two new StaticValueUtils:
- `isAllConstantIntValue` checks if an array of `OpFoldResult` are all
equal to a passed `int64_t` value.
- `areConstantIntValues` checks if an array of `OpFoldResult` are all
equal to a passed array of `int64_t` values.

fixes https://github.com/llvm/llvm-project/issues/112435

---------

Signed-off-by: Max Dawkins <max.dawkins@gmail.com>
2024-10-18 16:02:03 -04:00
donald chen
d69e94916e [mlir] [linalg] Fix bufferize error in tensor.parallel_insert_slice op (#98312)
tensor.parallel_insert_slice op has implicit inplace behavior. In the
"copy-before-write" bufferize mode, the resolveConflict function will
generate bufferize.copy, making the result incorrect. This patch fixes
this issue.
2024-07-11 20:16:06 +08:00
Gaurav Shukla
97069a8619 [MLIR] Generalize expand_shape to take shape as explicit input (#90040)
This patch generalizes tensor.expand_shape and memref.expand_shape to
consume the output shape as a list of SSA values. This enables us to
implement generic reshape operations with dynamic shapes using
collapse_shape/expand_shape pairs.

The output_shape input to expand_shape follows the static/dynamic
representation that's also used in `tensor.extract_slice`.

Differential Revision: https://reviews.llvm.org/D140821

---------

Signed-off-by: Gaurav Shukla<gaurav.shukla@amd.com>
Signed-off-by: Gaurav Shukla <gaurav.shukla@amd.com>
Co-authored-by: Ramiro Leal-Cavazos <ramiroleal050@gmail.com>
2024-04-30 09:28:35 -07:00
Mehdi Amini
8c0341df02 Revert "[MLIR] Generalize expand_shape to take shape as explicit input" (#89540)
Reverts llvm/llvm-project#69267

this broke some bots.
2024-04-21 14:33:48 +02:00
Gaurav Shukla
e095d978ba [MLIR] Generalize expand_shape to take shape as explicit input (#69267)
This patch generalizes tensor.expand_shape and memref.expand_shape to
consume the output shape as a list of SSA values. This enables us to
implement generic reshape operations with dynamic shapes using
collapse_shape/expand_shape pairs.

The output_shape input to expand_shape follows the static/dynamic
representation that's also used in `tensor.extract_slice`.

Differential Revision: https://reviews.llvm.org/D140821

Co-authored-by: Ramiro Leal-Cavazos <ramiroleal050@gmail.com>
2024-04-21 07:37:02 -04:00
Justin Lebar
fab2bb8bfd Add llvm::min/max_element and use it in llvm/ and mlir/ directories. (#84678)
For some reason this was missing from STLExtras.
2024-03-10 20:00:13 -07:00
ian Bearman
067d2779fc [MLIR] Setting MemorySpace During Bufferization (#78484)
Collection of changes with the goal of being able to convert `encoding`
to `memorySpace` during bufferization
- new API for encoder to allow implementation to select destination
memory space
- update existing bufferization implementations to support the new
interface
2024-02-08 16:59:37 +01:00
Matthias Springer
5cc0f76d34 [mlir][IR] Add rewriter API for moving operations (#78988)
The pattern rewriter documentation states that "*all* IR mutations [...]
are required to be performed via the `PatternRewriter`." This commit
adds two functions that were missing from the rewriter API:
`moveOpBefore` and `moveOpAfter`.

After an operation was moved, the `notifyOperationInserted` callback is
triggered. This allows listeners such as the greedy pattern rewrite
driver to react to IR changes.

This commit narrows the discrepancy between the kind of IR modification
that can be performed and the kind of IR modifications that can be
listened to.
2024-01-25 11:01:28 +01:00
Matthias Springer
1abd8d1a8d [mlir][Interfaces] Add SubsetOpInterface and SubsetExtractionOpInterface (#70617)
There is currently an op interface for subset insertion ops
(`SubsetInsertionOpInterface`), but not for subset extraction ops. This
commit adds `SubsetExtractionOpInterface` to `mlir/Interfaces`, as well
as a common dependent op interface: `SubsetOpInterface`.

- `SubsetOpInterface` is for ops that operate on tensor subsets. It
provides interface methods to check if two subset ops operate on
equivalent or disjoint subsets. Ops that implement this interface must
implement either `SubsetExtractionOpInterface` or
`SubsetInsertionOpInterface`.
- `SubsetExtractionOpInterface` is for ops that extract from a tensor at
a subset. E.g., `tensor.extract_slice`, `tensor.gather`,
`vector.transfer_read`. Current implemented only on
`tensor.extract_slice`.
- `SubsetInsertionOpInterface` is for ops that insert into a destination
tensor at a subset. E.g., `tensor.insert_slice`,
`tensor.parallel_insert_slice`, `tensor.scatter`,
`vector.transfer_write`. Currently only implemented on
`tensor.insert_slice`, `tensor.parallel_insert_slice`.

Other changes:
- Rename `SubsetInsertionOpInterface.td` to `SubsetOpInterface.td`.
- Add helper functions to `ValueBoundsOpInterface.cpp` for checking
whether two slices are disjoint.

The new interfaces will be utilized by a new "loop-invariant subset
hoisting"
transformation. (This new transform is roughly
what `Linalg/Transforms/SubsetHoisting.cpp` is doing, but in a generic
and interface-driven way.)
2023-11-01 10:26:31 +09:00
Matthias Springer
5558504374 [mlir][IR] Make OpOperand comparable (#70410)
Two `OpOperand`s are the same if they belong to the same owner and have
the same operand number. There are currently no comparison operators
defined on `OpOperand` and we work around this in multiple places by
comparing pointers.

Note: `OpOperand`s are stored in an op, so it is valid to compare their
pointers to determine if they are the same operand. E.g.,
`getOperandNumber` is also implemented via pointer arithmetics.
2023-10-27 15:51:45 +09:00
Matthias Springer
ea71d2d0fe [mlir][tensor][bufferize] Reshapes: Fix memory side effects and memory space (#68195)
* `tensor.collapse_shape` may bufferize to a memory read because the op
may have to reallocate the source buffer.
* `tensor.reshape` should not use `bufferization.clone` for
reallocation. This op has requirements wrt. the order of buffer
writes/reads. Use `memref.alloc` and `memref.copy` instead. Also fix a
bug where the memory space of the source buffer was not propagated to
the reallocated buffer.
2023-10-05 14:33:04 +02:00
Matthias Springer
58678d3bcf [mlir][tensor][bufferize] tensor.empty bufferizes to allocation (#68201)
`BufferizableOpInterface::bufferizesToAllocation` is queried when
forming equivalence sets during bufferization. It is not really needed
for ops like `tensor.empty` which do not have tensor operands, but it
should be added for consistency.

This change should have been part of #68080. No test is added because
the return value of this function is irrelevant for ops without tensor
operands. (However, this function acts as a form documentation,
describing the bufferization semantics of the op.)
2023-10-05 14:06:00 +02:00
Matthias Springer
8823e961f6 [mlir][ODS] Change get...Mutable to return OpOperand & for single operands (#66519)
The TableGen code generator now generates C++ code that returns a single
`OpOperand &` for `get...Mutable` of operands that are not variadic and
not optional. `OpOperand::set`/`assign` can be used to set a value (same
as `MutableOperandRange::assign`). This is safer than
`MutableOperandRange` because only single values (and no longer
`ValueRange`) can be assigned.

E.g.:
```
// Assignment of multiple values to non-variadic operand.
// Before: Compiles, but produces invalid op.
// After: Compilation error.
extractSliceOp.getSourceMutable().assign({v1, v2});
```
2023-10-04 08:35:40 +02:00
Matthias Springer
464dfeba44 [mlir][tensor][bufferize] tensor.empty bufferizes to an allocation (#68080)
Make `tensor.empty` bufferizable, so that the
`-empty-tensor-to-alloc-tensor` pass becomes optional. This makes the
bufferization easier to use. `tensor.empty` used to be non-bufferizable,
so that there two separate ops, one that can be optimized away
(`tensor.empty`) and one that is guaranteed to bufferize to an
allocation (`bufferization.alloc_tensor`). With the recent improvements
of "empty tensor elimination" this is no longer needed and
`bufferization.alloc_tensor` can be phased out.
2023-10-03 16:00:37 +02:00
Spenser Bauman
0a0c7e8978 [mlir][tensor] Bufferize tensor.reshape with non-identity layouts (#65654)
Bufferization of tensor.reshape generates a memref.reshape operation.
memref.reshape requires the source memref to have an identity layout.
The bufferization process may result in the source memref having a
non-identity layout, resulting in a verification failure.

This change causes the bufferization interface for tensor.reshape to
copy the source memref to a new buffer when the source has a
non-identity layout.
2023-09-19 09:50:43 +09:00
Martin Erhart
6bf043e743 [mlir][bufferization] Remove allow-return-allocs and create-deallocs pass options, remove bufferization.escape attribute (#66619)
This commit removes the deallocation capabilities of
one-shot-bufferization. One-shot-bufferization should never deallocate
any memrefs as this should be entirely handled by the
ownership-based-buffer-deallocation pass going forward. This means the
`allow-return-allocs` pass option will default to true now,
`create-deallocs` defaults to false and they, as well as the escape
attribute indicating whether a memref escapes the current region, will
be removed. A new `allow-return-allocs-from-loops` option is added as a
temporary workaround for some bufferization limitations.
2023-09-18 16:44:48 +02:00
Matthias Springer
0f952cfe24 [mlir][IR] Change MutableOperandRange::operator[] to return an OpOperand & (#66515)
`operator[]` returns `OpOperand &` instead of `Value`.

* This allows users to get OpOperands by name instead of "magic" number.
E.g., `extractSliceOp->getOpOperand(0)` can be written as
`extractSliceOp.getSourceMutable()[0]`.
* `OperandRange` provides a read-only API to operands: `operator[]`
returns `Value`. `MutableOperandRange` now provides a mutable API:
`operator[]` returns `OpOperand &`, which can be used to set operands.

Note: The TableGen code generator could be changed to return `OpOperand
&` (instead of `MutableOperandRange`) for non-variadic and non-optional
arguments in a subsequent change. Then the `[0]` part in the above
example would no longer be necessary.
2023-09-18 09:43:03 +02:00
Martin Erhart
c199f7dc62 Revert "[mlir][bufferization] Remove allow-return-allocs and create-deallocs pass options, remove bufferization.escape attribute"
This reverts commit 6a91dfedeb.

This caused problems in downstream projects. We are reverting to give
them more time for integration.
2023-09-13 13:53:48 +00:00
Matthias Springer
8143307b33 [mlir][bufferization] Generalize tensor slice rules to subset ops (#65619)
This commit generalizes the special
tensor.extract_slice/tensor.insert_slice bufferization rules to tensor
subset ops.

Ops that insert a tensor into a tensor at a specified subset (e.g.,
tensor.insert_slice, tensor.scatter) can implement the
`SubsetInsertionOpInterface`.

Apart from adding a new op interface (extending the API), this change is
NFC. The only ops that currently implement the new interface are
tensor.insert_slice and tensor.parallel_insert_slice, and those ops were
are supported by One-Shot Bufferize.
2023-09-13 12:27:19 +02:00
Martin Erhart
6a91dfedeb [mlir][bufferization] Remove allow-return-allocs and create-deallocs pass options, remove bufferization.escape attribute
This is the first commit in a series with the goal to rework the
BufferDeallocation pass. Currently, this pass heavily relies on copies
to perform correct deallocations, which leads to very slow code and
potentially high memory usage. Additionally, there are unsupported cases
such as returning memrefs which this series of commits aims to add
support for as well.

This first commit removes the deallocation capabilities of
one-shot-bufferization.One-shot-bufferization should never deallocate any
memrefs as this should be entirely handled by the buffer-deallocation pass
going forward. This means the allow-return-allocs pass option will
default to true now, create-deallocs defaults to false and they, as well
as the escape attribute indicating whether a memref escapes the current region,
will be removed.

The documentation should w.r.t. these pass option changes should also be
updated in this commit.

Reviewed By: springerm

Differential Revision: https://reviews.llvm.org/D156662
2023-09-13 09:30:22 +00:00
Matthias Springer
878950b82c [mlir][bufferization] Simplify getBufferType
`getBufferType` computes the bufferized type of an SSA value without bufferizing any IR. This is useful for predicting the bufferized type of iter_args of a loop.

To avoid endless recursion (e.g., in the case of "scf.for", the type of the iter_arg depends on the type of init_arg and the type of the yielded value; the type of the yielded value depends on the type of the iter_arg again), `fixedTypes` was used to fall back to "fixed" type. A simpler way is to maintain an "invocation stack". `getBufferType` implementations can then inspect the invocation stack to detect repetitive computations (typically when computing the bufferized type of a block argument).

Also improve error messages in case of inconsistent memory spaces inside of a loop.

Differential Revision: https://reviews.llvm.org/D158060
2023-08-16 15:02:07 +02:00
Matthias Springer
a02ad6c177 [mlir][bufferization] Generalize getAliasingOpResults to getAliasingValues
This revision is needed to support bufferization of `cf.br`/`cf.cond_br`. It will also be useful for better analysis of loop ops.

This revision generalizes `getAliasingOpResults` to `getAliasingValues`. An OpOperand can now not only alias with OpResults but also with BlockArguments. In the case of `cf.br` (will be added in a later revision): a `cf.br` operand will alias with the corresponding argument of the destination block.

If an op does not implement the `BufferizableOpInterface`, the analysis in conservative. It previously assumed that an OpOperand may alias with each OpResult. It now assumes that an OpOperand may alias with each OpResult and each BlockArgument of the entry block.

Differential Revision: https://reviews.llvm.org/D157957
2023-08-15 15:02:47 +02:00
Matthias Springer
ef4f5357e3 [mlir][linalg] BufferizeToAllocationOp: Do not copy uninitialized buffers
Tensors/buffers that do not have any defined contents (e.g., `tensor.empty`) are no longer copied.

Differential Revision: https://reviews.llvm.org/D154081
2023-07-04 16:40:10 +02:00
Ingo Müller
9dbb8eefd4 [mlir][tensor] Implement getBufferType for ReshapeOp.
This function should be implemented for ops that work in one-shot
bufferization.

Reviewed By: springerm

Differential Revision: https://reviews.llvm.org/D151548
2023-06-02 13:40:48 +00:00
Ingo Müller
45aaa67fce [mlir][tensor] Fix one-shot bufferization of tensor.reshape.
I believe that the previous implementation did not work on any input. It
called getMemRefType with `layout = {}`, presumably with the intention
to create a MemrefType with identity layout. However, the implementation
of that function returns a MemrefType with *unknown* layout if it is
provided with a default-constructed layout attribute. This patch uses
getMemRefTypeWithStaticIdentityLayout instead, with has identical
behavior except for the case of a default-constructed layout, which it
passes on as-is to the MemrefType.

This problem did not surface in the test because tensor.reshape was not
tested with -one-shot-bufferize. This patch introduces a test copied
from the tests for -tesnor-bufferize adapted in as follows: since the
test is run with "bufferize-function-boundaries", a tensor that is
passed into the function is bufferized into a memref with unknown
layout, which wouldn't be a valid intput for memref.reshape, so the
tests now uses a tensor constructed with arith.constant inside of the
function.

Reviewed By: springerm

Differential Revision: https://reviews.llvm.org/D151544
2023-05-26 09:39:49 +00:00
Tres Popp
68f58812e3 [mlir] Move casting calls from methods to function calls
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
2023-05-26 10:29:55 +02:00
Matthias Springer
481b254e45 [mlir][tensor][bufferize] Bufferize tensor.splat op
The op bufferizes similarly to tensor.generate: it is lowered to a linalg.map, which may then lower to a loop nest that fills the buffer.

Differential Revision: https://reviews.llvm.org/D150952
2023-05-22 14:31:39 +02:00
Kai Sasaki
6cd7b655d8 [mlir][bufferization] Prevent crash in one shot bufferization with unranked tensor cast
One shot bufferization does not support bufferizing the cast between unranked tensors. To prevent the crash, we can check the compatibility of the result type in advance. Reported in https://github.com/llvm/llvm-project/issues/62369.

Reviewed By: springerm

Differential Revision: https://reviews.llvm.org/D149239
2023-05-19 08:54:43 +09:00
Tres Popp
5550c82189 [mlir] Move casting calls from methods to function calls
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.

Caveats include:
- This clang-tidy script probably has more problems.
- This only touches C++ code, so nothing that is being generated.

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 first patch was created with the following steps. The intention is
to only do automated changes at first, so I waste less time if it's
reverted, and so the first mass change is more clear as an example to
other teams that will need to follow similar steps.

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:
   https://github.com/llvm/llvm-project/compare/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.
4. Some changes have been deleted for the following reasons:
   - Some files had a variable also named cast
   - Some files had not included a header file that defines the cast
     functions
   - Some files are definitions of the classes that have the casting
     methods, so the code still refers to the method instead of the
     function without adding a prefix or removing the method declaration
     at the same time.

```
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

git restore mlir/lib/IR mlir/lib/Dialect/DLTI/DLTI.cpp\
            mlir/lib/Dialect/Complex/IR/ComplexDialect.cpp\
            mlir/lib/**/IR/\
            mlir/lib/Dialect/SparseTensor/Transforms/SparseVectorization.cpp\
            mlir/lib/Dialect/Vector/Transforms/LowerVectorMultiReduction.cpp\
            mlir/test/lib/Dialect/Test/TestTypes.cpp\
            mlir/test/lib/Dialect/Transform/TestTransformDialectExtension.cpp\
            mlir/test/lib/Dialect/Test/TestAttributes.cpp\
            mlir/unittests/TableGen/EnumsGenTest.cpp\
            mlir/test/python/lib/PythonTestCAPI.cpp\
            mlir/include/mlir/IR/
```

Differential Revision: https://reviews.llvm.org/D150123
2023-05-12 11:21:25 +02:00
Matthias Springer
4c48f016ef [mlir][Affine][NFC] Wrap dialect in "affine" namespace
This cleanup aligns the affine dialect with all the other dialects.

Differential Revision: https://reviews.llvm.org/D148687
2023-04-20 11:19:21 +09:00
Matthias Springer
7c06f63176 [mlir][tensor][bufferize] Fix dealloc placement in scf.forall op
The terminator of this op is special: it does not just yield a value,
but bufferizes to a memcpy. This requires special treatment to make sure
that deallocs are placed after the memcpy. (By default, deallocs are
placed right before the terminator.)

Differential Revision: https://reviews.llvm.org/D148408
2023-04-16 09:34:43 +09:00
Jakub Kuderski
a0a76804c4 [ADT] Allow llvm::enumerate to enumerate over multiple ranges
This does not work by a mere composition of `enumerate` and `zip_equal`,
because C++17 does not allow for recursive expansion of structured
bindings.

This implementation uses `zippy` to manage the iteratees and adds the
stream of indices as the first zipped range. Because we have an upfront
assertion that all input ranges are of the same length, we only need to
check if the second range has ended during iteration.

As a consequence of using `zippy`, `enumerate` will now follow the
reference and lifetime semantics of the `zip*` family of functions. The
main difference is that `enumerate` exposes each tuple of references
through a new tuple-like type `enumerate_result`, with the familiar
`.index()` and `.value()` member functions.

Because the `enumerate_result` returned on dereference is a
temporary, enumeration result can no longer be used through an
lvalue ref.

Reviewed By: dblaikie, zero9178

Differential Revision: https://reviews.llvm.org/D144503
2023-03-15 19:34:22 -04:00
Matthias Springer
9fa6b3504b [mlir][bufferization] Improve aliasing OpOperand/OpResult property
`getAliasingOpOperands`/`getAliasingOpResults` now encodes OpOperand/OpResult, buffer relation and a degree of certainty. E.g.:
```
// aliasingOpOperands(%r) = {(%t, EQUIV, DEFINITE)}
// aliasingOpResults(%t) = {(%r, EQUIV, DEFINITE)}
%r = tensor.insert %f into %t[%idx] : tensor<?xf32>

// aliasingOpOperands(%r) = {(%t0, EQUIV, MAYBE), (%t1, EQUIV, MAYBE)}
// aliasingOpResults(%t0) = {(%r, EQUIV, MAYBE)}
// aliasingOpResults(%t1) = {(%r, EQUIV, MAYBE)}
%r = arith.select %c, %t0, %t1 : tensor<?xf32>
```

`BufferizableOpInterface::bufferRelation` is removed, as it is now part of `getAliasingOpOperands`/`getAliasingOpResults`.

This change allows for better analysis, in particular wrt. equivalence. This allows additional optimizations and better error checking (which is sometimes overly conservative). Examples:

* EmptyTensorElimination can eliminate `tensor.empty` inside `scf.if` blocks. This requires a modeling of equivalence: It is not a per-OpResult property anymore. Instead, it can be specified for each OpOperand and OpResult. This is important because `tensor.empty` may be eliminated only if all values on the SSA use-def chain to the final consumer (`tensor.insert_slice`) are equivalent.
* The detection of "returning allocs from a block" can be improved. (Addresses a TODO in `assertNoAllocsReturned`.) This allows us to bufferize IR such as "yielding a `tensor.extract_slice` result from an `scf.if` branch", which currently fails to bufferize because the alloc detection is too conservative.
* Better bufferization of loops. Aliases of the iter_arg can be yielded (even if they are not equivalent) without having to realloc and copy the entire buffer on each iteration.

The above-mentioned examples are not yet implemented with this change. This change just improves the BufferizableOpInterface, its implementations and related helper functions, so that better aliasing information is available for each op.

Differential Revision: https://reviews.llvm.org/D142129
2023-02-09 11:35:03 +01:00
Matthias Springer
330372f2c5 [mlir][tensor][bufferize] tensor.empty does not define the result tensor contents
This is encoded in the `BufferizableOpInterface` via `resultBufferizesToMemoryWrite = false`.

Differential Revision: https://reviews.llvm.org/D143181
2023-02-06 10:26:38 +01:00
Matthias Springer
b6ae3f8873 [mlir][tensor][bufferize] Implement getBufferType for CastOp
This interface method is used to compute the buffer type of a value during bufferization. It was missing. This is interface method is used during loop bufferization.

Also fix a bug where a cast from an unranked tensor to a ranked tensor type did not always apply a fully dynamic layout map on the result memref.

Differential Revision: https://reviews.llvm.org/D143063
2023-02-01 14:24:10 +01:00
Matthias Springer
1ac248e485 [mlir][bufferization][NFC] Rename getAliasingOpOperand/getAliasingOpResult
* `getAliasingOpOperand` => `getAliasingOpOperands`
* `getAliasingOpResult` => `getAliasingOpResults`

Also a few minor code cleanups and better documentation.

Differential Revision: https://reviews.llvm.org/D142979
2023-02-01 10:07:41 +01:00
Matthias Springer
148432ea84 [mlir][bufferization][NFC] Rename BufferRelation::None to BufferRelation::Unknown
The previous name was incorrect. `None` does not mean that there is no buffer relation between two buffers (seems to imply that they do not alias for sure); instead it means that there is no further information available.

Differential Revision: https://reviews.llvm.org/D142870
2023-01-30 11:09:28 +01:00
Matthias Springer
1840d18a10 [mlir][bufferization][NFC] Rename: "last-write" -> "definition"
The previous lingo was confusing. There are no writes on tensors. There are only definitions.

Also some minor cleanup and better documentation.

Differential Revision: https://reviews.llvm.org/D141790
2023-01-30 09:51:53 +01:00
Mehdi Amini
ab32f5b7ef Apply clang-tidy fixes for readability-simplify-boolean-expr in BufferizableOpInterfaceImpl.cpp (NFC) 2022-12-28 22:42:39 +00:00
Matthias Springer
e5dc99e642 [mlir][tensor][bufferize] Improve bufferization of DimOp/RankOp
The tensor operands do not bufferize to a memory read.

Differential Revision: https://reviews.llvm.org/D140007
2022-12-14 12:47:46 +01:00
Matthias Springer
be630f07de [mlir][bufferize] Implement BufferizableOpInterface for tensor.empty
The op is not bufferizable but should be analyzable (for `EliminateEmptyTensors`, which uses the bufferization infrastructure).

Also improve debugging functionality and error messages.

Also adds a missing pass to the sparse pipeline. (tensor.empty should be replaced with bufferization.alloc_tensor, but it sometimes used to work without depending on how the tensor.empty is used. Now we always fail explicitly.)
2022-12-12 14:19:38 +01:00
Matthias Springer
13593dc9dc [mlir][tensor][bufferize] Fix tensor.insert_slice regression
This reverts D132662 (apart from overall cleanups), which introduced a too aggressive optimization for tensor.insert_slice bufferization. Instead, bufferizesToMemoryRead is improved to handle some of these cases. The remaining cases can still bufferize efficiently when running the canonicalizer before the bufferization.

Differential Revision: https://reviews.llvm.org/D138745
2022-11-26 19:14:33 +01:00
Lei Zhang
9bb633741a [mlir][bufferization] Support general Attribute as memory space
MemRef has been accepting a general Attribute as memory space for
a long time. This commits updates bufferization side to catch up,
which allows downstream users to plugin customized symbolic memory
space. This also eliminates quite a few `getMemorySpaceAsInt`
calls, which is deprecated.

Reviewed By: springerm

Differential Revision: https://reviews.llvm.org/D138330
2022-11-21 09:40:50 -05:00
Matthias Springer
09dfb44193 [mlir][tensor][bufferize] Support memory_space for tensor.pad
This change adds memory space support to tensor.pad. (tensor.generate and tensor.from_elements do not support memory spaces yet.)

The memory space is inferred from the buffer of the source tensor.

Instead of lowering tensor.pad to tensor.generate + tensor.insert_slice, it is now lowered to bufferization.alloc_tensor (with the correct memory space) + linalg.map + tensor.insert_slice.

Memory space support for the remaining two tensor ops is left for a later point, as this requires some more design discussions.

Differential Revision: https://reviews.llvm.org/D136265
2022-10-27 12:29:57 +02:00
Matthias Springer
c1f0a15c65 [mlir][tensor][bufferize] Lower tensor.generate to linalg.map
There is no memref equivalent of tensor.generate. The purpose of this change is to avoid creating scf.parallel loops during bufferization.

Differential Revision: https://reviews.llvm.org/D136767
2022-10-27 12:03:13 +02:00
Matthias Springer
2d5edc644d [mlir][bufferize] Provide default BufferizableOpInterface impl for destination style ops
tensor.insert and tensor.insert_slice (as destination style ops) do no longer need to implement the entire BufferizableOpInterface.

Differential Revision: https://reviews.llvm.org/D136347
2022-10-27 10:52:47 +02:00
Matthias Springer
6cdd34b973 [mlir][tensor][bufferize] Bufferize inserts into equivalent tensors in-place
Inserting a tensor into an equivalent tensor is a no-op after bufferization. No alloc is needed.

Differential Revision: https://reviews.llvm.org/D132662
2022-10-06 15:06:33 +09:00