Commit Graph

134 Commits

Author SHA1 Message Date
Kazu Hirata
fcb1591b46 [IR] Migrate away from PointerUnion::{is,get} (NFC) (#119802)
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.
2024-12-13 08:00:45 -08:00
Ian Wood
06514c5501 [MLIR][Linalg] Fix linalg crash during elementwise op fusion (#117667)
`isOpOperandCanBeDroppedAfterFusedLinalgs` crashes when `indexingMaps`
is empty. This can occur when `producer` only has DPS init operands and
`consumer ` only has a single DPS input operand (all operands are
ignored and nothing gets added to `indexingMaps`). This is because
`concatAffineMaps` wasn't handling the maps being empty properly.


Similar to `canOpOperandsBeDroppedImpl`, I added an early return when
the maps are of size zero. Additionally, `concatAffineMaps`'s
declaration comment says it returns an empty map when `maps` is empty
but it has no way to get the `MLIRContext` needed to construct the empty
affine map when the array is empty. So, I changed this to take the
context.


__NOTE: concatAffineMaps now takes an MLIRContext to be able to
construct an empty map in the case where `maps` is empty.__

---------

Signed-off-by: Ian Wood <ianwood2024@u.northwestern.edu>
Co-authored-by: Quinn Dawkins <quinn.dawkins@gmail.com>
2024-11-26 16:00:18 -08:00
Andrzej Warzyński
6d11494414 [mlir][Linalg] Refine how broadcast dims are treated (#99015)
This PR fixes how broadcast dims (identified as "zero" results in
permutation maps) corresponding to a reduction iterator are vectorised
in the case of generic Ops. Here's an example:

```mlir
  #map = affine_map<(d0, d1, d2, d3) -> (d0, d1, d2, d3)>
  #map1 = affine_map<(d0, d1, d2, d3) -> (d0, d1, d2, 0)>

  func.func @generic_with_reduction_and_broadcast(%arg0: tensor<1x12x197x197xf32>) -> (tensor<1x12x197x1xf32>) {
    %0 = tensor.empty() : tensor<1x12x197x1xf32>

    %1 = linalg.generic {indexing_maps = [#map, #map1],
                        iterator_types = ["parallel", "parallel", "parallel", "reduction"]}
      ins(%arg0 : tensor<1x12x197x197xf32>)
      outs(%0 : tensor<1x12x197x1xf32>) {

    ^bb0(%in: f32, %out: f32):
      %818 = arith.addf %in, %out : f32
      linalg.yield %818 : f32
    } -> tensor<1x12x197x1xf32>
    return %1 : tensor<1x12x197x1xf32>
  }
```

This is a perfectly valid Generic Op, but currently triggers two issues
in the vectoriser. The root cause is this map:

```mlir
  #map1 = affine_map<(d0, d1, d2, d3) -> (d0, d1, d2, 0)>
```

This map triggers an assert in `reindexIndexingMap` -  this hook
incorrectly assumes that every result in the input map is a `dim`
expression and that there are no constants. That's not the case in this
example. `reindexIndexingMap` is extended to allow maps like the one
above. For now, only constant "zero" results are allowed. This can be
extended in the future once a good motivating example is available.

Separately, the permutation map highlighted above "breaks" mask
calculation (ATM masks are always computed, even in the presence of
static shapes). When applying the following permutation:
```mlir
  (d0, d1, d2, d3) -> (d0, d1, d2, 0)
```

to these canonical shapes (corresponding to the example above):
```
  (1, 12, 197, 197)
```
we end up with the following error:
```bash
error: vector types must have positive constant sizes but got 1, 12, 197, 0
```

The error makes sense and indicates that we should update the
permutation map above to:
```
  (d0, d1, d2, d3) -> (d0, d1, d2)
```

This would correctly give the following vector type:
```
  vector<1x12x197xi1>
```

Fixes #97247
2024-09-26 16:17:15 +01:00
Kazu Hirata
5262865aac [mlir] Construct SmallVector with ArrayRef (NFC) (#101896) 2024-08-04 11:43:05 -07:00
Andrzej Warzyński
2ee5586ac7 [mlir][vector] Make the in_bounds attribute mandatory (#97049)
At the moment, the in_bounds attribute has two confusing/contradicting
properties:
  1. It is both optional _and_ has an effective default-value.
  2. The default value is "out-of-bounds" for non-broadcast dims, and
     "in-bounds" for broadcast dims.

(see the `isDimInBounds` vector interface method for an example of this
"default" behaviour [1]).

This PR aims to clarify the logic surrounding the `in_bounds` attribute
by:
  * making the attribute mandatory (i.e. it is always present),
  * always setting the default value to "out of bounds" (that's
    consistent with the current behaviour for the most common cases).

#### Broadcast dimensions in tests

As per [2], the broadcast dimensions requires the corresponding
`in_bounds` attribute to be `true`:
```
  vector.transfer_read op requires broadcast dimensions to be in-bounds
```

The changes in this PR mean that we can no longer rely on the
default value in cases like the following (dim 0 is a broadcast dim):
```mlir
  %read = vector.transfer_read %A[%base1, %base2], %f, %mask
      {permutation_map = affine_map<(d0, d1) -> (0, d1)>} :
    memref<?x?xf32>, vector<4x9xf32>
```

Instead, the broadcast dimension has to explicitly be marked as "in
bounds:

```mlir
  %read = vector.transfer_read %A[%base1, %base2], %f, %mask
      {in_bounds = [true, false], permutation_map = affine_map<(d0, d1) -> (0, d1)>} :
    memref<?x?xf32>, vector<4x9xf32>
```

All tests with broadcast dims are updated accordingly.

#### Changes in "SuperVectorize.cpp" and "Vectorization.cpp"

The following patterns in "Vectorization.cpp" are updated to explicitly
set the `in_bounds` attribute to `false`:
* `LinalgCopyVTRForwardingPattern` and `LinalgCopyVTWForwardingPattern`

Also, `vectorizeAffineLoad` (from "SuperVectorize.cpp") and
`vectorizeAsLinalgGeneric` (from "Vectorization.cpp") are updated to
make sure that xfer Ops created by these hooks set the dimension
corresponding to broadcast dims as "in bounds". Otherwise, the Op
verifier would complain

Note that there is no mechanism to verify whether the corresponding
memory access are indeed in bounds. Still, this is consistent with the
current behaviour where the broadcast dim would be implicitly assumed
to be "in bounds".

[1]
4145ad2bac/mlir/include/mlir/Interfaces/VectorInterfaces.td (L243-L246)
[2]
https://mlir.llvm.org/docs/Dialects/Vector/#vectortransfer_read-vectortransferreadop
2024-07-16 16:49:52 +01:00
Ramkumar Ramachandra
db791b278a mlir/LogicalResult: move into llvm (#97309)
This patch is part of a project to move the Presburger library into
LLVM.
2024-07-02 10:42:33 +01:00
Kazu Hirata
b7b337fb91 [mlir] Use llvm::unique (NFC) (#96415) 2024-06-24 11:54:02 -07:00
Ramkumar Ramachandra
0fb216fb2f mlir/MathExtras: consolidate with llvm/MathExtras (#95087)
This patch is part of a project to move the Presburger library into
LLVM.
2024-06-11 23:00:02 +01:00
Christian Sigg
a5757c5b65 Switch member calls to isa/dyn_cast/cast/... to free function calls. (#89356)
This change cleans up call sites. Next step is to mark the member
functions deprecated.

See https://mlir.llvm.org/deprecation and
https://discourse.llvm.org/t/preferred-casting-style-going-forward.
2024-04-19 15:58:27 +02:00
Jakub Kuderski
971b852546 [mlir][NFC] Simplify type checks with isa predicates (#87183)
For more context on isa predicates, see:
https://github.com/llvm/llvm-project/pull/83753.
2024-04-01 11:40:09 -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
Uday Bondhugula
fe8a62c463 [MLIR] Fix crash in AffineMap::replace for zero result maps (#80930)
Fix obvious bug in AffineMap::replace for the case of zero result maps.
Extend/complete inferExprsFromList to work with empty expression lists.
2024-02-08 19:16:29 +05:30
Matthias Springer
32c3decb77 [mlir][vector] Modernize vector.transpose op (#72594)
* Declare arguments/results with `let` statements.
* Rename `transp` to `permutation`.
* Change type of `transp` from `I64ArrayAttr` to `DenseI64ArrayAttr`
(provides direct access to `ArrayRef<int64_t>` instead of `ArrayAttr`).
2023-11-20 11:25:35 +01:00
Benjamin Kramer
d9c5e8a230 [mlir][affine] Remove unused captures 2023-11-18 21:03:22 +01:00
long.chen
dc4786b487 [mlir][affine] remove divide zero check when simplifer affineMap (#64622) (#68519)
When performing constant folding on the affineApplyOp, there is a
division of 0 in the affine map.
[related issue](https://github.com/llvm/llvm-project/issues/64622)

---------

Co-authored-by: Javier Setoain <jsetoain@users.noreply.github.com>
2023-11-19 02:14:53 +08:00
long.chen
1609f1c2a5 [mlir][affine][nfc] cleanup deprecated T.cast style functions (#71269)
detail see the docment: https://mlir.llvm.org/deprecation/

Not all changes are made manually, most of them are made through a clang
tool I wrote https://github.com/lipracer/cpp-refactor.
2023-11-14 13:01:19 +08:00
Uday Bondhugula
d1ceb740ab [MLIR][Affine] NFC. Fix stale comments and style in affine libraries (#71660)
Fix stale comments in affine libraries; fix clang-tidy warnings/style.
NFC.
2023-11-09 07:08:44 +05:30
Chengji Yao
b0d5b4d252 [MLIR][Mesh] Add sharding propagation pass (#71261)
Add a pass that propagates sharding information throughout the graph.
After this pass, each of the operations' operands and results is
annotated with a mesh.shard operation.

The pass is driven by a newly added ShardingInterface, and an implementation
for element-wise and matmul ops in the TOSA dialect is provided.
2023-11-03 21:07:31 -07:00
Mehdi Amini
466abaf152 Revert "[MLIR][Mesh] Add sharding propagation pass (#69665)"
This reverts commit 9d9400d7de.
This reverts commit bda763aea0.

The buildbot is broken and tests are failing.
2023-11-03 17:52:41 -07:00
Chengji Yao
9d9400d7de [MLIR][Mesh] Add sharding propagation pass (#69665)
Add a pass that propagates sharding information throughout the graph.
After this pass, each of the operations' operands and results is
annotated with a `mesh.shard` operation, and the operations themselves
are added with sharding option attributes.

The pass is driven by  a newly added `ShardingInterface`, and an implementation
for element-wise and matmul ops in the TOSA dialect is provided.
2023-11-03 17:12:42 -07:00
Matthias Springer
26e35b0fa8 [mlir][NFC] Move foldAttributesIntoMap to IR build unit (#70155)
`foldAttributesIntoMap` is a helper function that folds constant
`OpFoldResult` into an affine map. This commit moves the function from
the affine dialect to `AffineMap.h`, so that it can be used without
depending on the affine dialect.
2023-10-25 17:50:30 +09:00
Diego Caballero
13f15e8f14 [mlir][Vector] Fix vectorization of generic ops with transposed outputs
This patch fixes a bug in the way we compute the vector type for vector
transfer writes when the value to store needs to be transposed.

Reviewed By: nicolasvasilache, mravishankar

Differential Revision: https://reviews.llvm.org/D153687
2023-06-26 20:24:29 +00:00
Tres Popp
c1fa60b4cd [mlir] Update method cast calls 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 follows a previous patch that updated calls
`op.cast<T>()-> cast<T>(op)`. However some cases could not handle an
unprefixed `cast` call due to occurrences of variables named cast, or
occurring inside of class definitions which would resolve to the method.
All C++ files that did not work automatically with `cast<T>()` are
updated here to `llvm::cast` and similar with the intention that they
can be easily updated after the methods are removed through a
find-replace.

See https://github.com/llvm/llvm-project/compare/main...tpopp:llvm-project:tidy-cast-check
for the clang-tidy check that is used and then update printed
occurrences of the function to include `llvm::` before.

One can then run the following:
```
ninja -C $BUILD_DIR clang-tidy

run-clang-tidy -clang-tidy-binary=$BUILD_DIR/bin/clang-tidy -checks='-*,misc-cast-functions'\
                 -export-fixes /tmp/cast/casts.yaml mlir/*\
                 -header-filter=mlir/ -fix

rm -rf $BUILD_DIR/tools/mlir/**/*.inc
```

Differential Revision: https://reviews.llvm.org/D150348
2023-05-12 11:21:30 +02:00
Rahul Joshi
24657a95c1 [NFC] Fix Windows builds that use MSVC 14.x
Differential Revision: https://reviews.llvm.org/D146769
2023-03-23 19:16:44 -07:00
Nicolas Vasilache
4dc72d47ce [mlir][Tensor] Add a FoldTensorSubsetOps pass and patterns
These patterns follow FoldMemRefAliasOps which is further refactored for reuse.
In the process, fix FoldMemRefAliasOps handling of strides for vector.transfer ops which was previously incorrect.

These opt-in patterns generalize the existing canonicalizations on vector.transfer ops.
In the future the blanket canonicalizations will be retired.
They are kept for now to minimize porting disruptions.

Differential Revision: https://reviews.llvm.org/D146624
2023-03-23 04:03:27 -07:00
Matthias Springer
5b0055a4ae [mlir][Analysis][NFC] Split FlatAffineValueConstraints into multiple classes
The new class hierarchy is as follows:

* `IntegerRelation` (no change)
* `IntegerPolyhedron` (no change)
* `FlatLinearConstraints`: provides an AffineExpr-based API
* `FlatLinearValueConstraints`: stores an additional mapping of non-local vars to SSA values
* `FlatAffineValueConstraints`: provides additional helper functions for Affine dialect ops
* `FlatAffineRelation` (no change)

`FlatConstraints` and `FlatValueConstraints` are moved from `MLIRAffineAnalysis` to `MLIRAnalysis` and can be used without depending on the Affine dialect.

This change is in preparation of D145681, which adds an MLIR interface that depends on `FlatConstraints` (and cannot depend on the Affine dialect or any other dialect).

Differential Revision: https://reviews.llvm.org/D146201
2023-03-23 09:38:12 +01:00
Nicolas Vasilache
255ba1c334 [mlir][AffineMap] NFC - Refactor getProjectedMap and split into projectDims and projectSymbols
The default behavior of getProjectedMap may be surprising as it implicitly compresses the dims and
the unused symbols.

Make these explicit in the API and refactor to more idiomatic implementations with better reuse.

Differential Revision: https://reviews.llvm.org/D146611
2023-03-22 05:30:48 -07:00
Kazu Hirata
0a81ace004 [mlir] Use std::optional instead of llvm::Optional (NFC)
This patch replaces (llvm::|)Optional< with std::optional<.  I'll post
a separate patch to remove #include "llvm/ADT/Optional.h".

This is part of an effort to migrate from llvm::Optional to
std::optional:

https://discourse.llvm.org/t/deprecating-llvm-optional-x-hasvalue-getvalue-getvalueor/63716
2023-01-14 01:25:58 -08:00
Kazu Hirata
a1fe1f5f77 [mlir] Add #include <optional> (NFC)
This patch adds #include <optional> to those files containing
llvm::Optional<...> or Optional<...>.

I'll post a separate patch to actually replace llvm::Optional with
std::optional.

This is part of an effort to migrate from llvm::Optional to
std::optional:

https://discourse.llvm.org/t/deprecating-llvm-optional-x-hasvalue-getvalue-getvalueor/63716
2023-01-13 21:05:06 -08:00
Kai Sasaki
5b779a3df3 [mlir][affine] Canonicalize single value affine.min/max
Canonicalize identity affine.min/max to allow further optimization to follow the def-use chain of the given values. The reported issue is https://github.com/llvm/llvm-project/issues/59399.

Differential Revision: https://reviews.llvm.org/D141354
2023-01-11 11:04:14 +09:00
Kazu Hirata
1a36588ec6 [mlir] Use std::nullopt instead of None (NFC)
This patch mechanically replaces None with std::nullopt where the
compiler would warn if None were deprecated.  The intent is to reduce
the amount of manual work required in migrating from Optional to
std::optional.

This is part of an effort to migrate from llvm::Optional to
std::optional:

https://discourse.llvm.org/t/deprecating-llvm-optional-x-hasvalue-getvalue-getvalueor/63716
2022-12-03 18:50:27 -08:00
Diego Caballero
bf3f7016b1 [mlir][NFC] Generalize getPermutedPosition
Small change to support projected permutations in the
`getPermutedPosition` utility. Renamed to `getResultPosition`.

Reviewed By: nicolasvasilache

Differential Revision: https://reviews.llvm.org/D138946
2022-12-01 18:58:25 +00:00
Uday Bondhugula
ddff3766b7 [MLIR] Simplify affine maps + operands exploiting IV info
Simplify affine expressions and maps while exploiting simple range and
step info of any IVs that are operands. This simplification is local,
O(1) and practically useful in several scenarios. Accesses with
floordiv's and mod's where the LHS is non-negative and bounded or is a
known multiple of a constant can often be simplified. This is
implemented as a canonicalization for all affine ops in a generic way:
all affine.load/store, vector_load/store, affine.apply, affine.min/max,
etc. ops.

Eg: For tiled loop nests accessing buffers this way:

affine.for %i = 0 to 1024 step 32 {
  affine.for %ii = 0 to 32 {
    affine.load [(%i + %ii) floordiv 32, (%i + %ii) mod 32]
  }
}

// Note that %i is a multiple of 32 and %ii < 32, hence:

(%i + %ii) floordiv 32 is the same as %i floordiv 32
(%i + %ii) mod 32 is the same as %ii mod 32.

The simplification leads to simpler index/subscript arithmetic for
multi-dimensional arrays and also in turn enables detection of spatial
locality (for vectorization for eg.), temporal locality or loop
invariance for hoisting or scalar replacement.

Differential Revision: https://reviews.llvm.org/D135085
2022-10-04 18:18:34 +05:30
Benoit Jacob
c3839c0b46 CombineContractBroadcast should not create dims unused in LHS+RHS
Differential Revision: https://reviews.llvm.org/D129087
2022-07-04 16:52:35 +00:00
Okwan Kwon
65bdeddb1e [mlir] Bubble up tensor.extract_slice above linalg operation
Bubble up extract_slice above Linalg operation.

A sequence of operations

    %0 = linalg.<op> ... arg0, arg1, ...
    %1 = tensor.extract_slice %0 ...

can be replaced with

    %0 = tensor.extract_slice %arg0
    %1 = tensor.extract_slice %arg1
    %2 = linalg.<op> ... %0, %1, ...

This results in the reduce computation of the linalg operation.

The implementation uses the tiling utility functions. One difference
from the tiling process is that we don't need to insert the checking
code for the out-of-bound accesses. The use of the slice itself
represents that the code writer is sure about the boundary condition.
To avoid adding the boundary condtion check code, `omitPartialTileCheck`
is introduced for the tiling utility functions.

Differential Revision: https://reviews.llvm.org/D122437
2022-03-31 16:48:38 +00:00
Benjamin Kramer
89d8035e36 Use llvm::append_range where applicable
It knows the size, so no need to call reserve beforehand. NFCI.
2022-03-18 20:05:48 +01:00
Benjamin Kramer
935a5f67d1 [AffineMap] Move result exprs into trailing storage. NFCI. 2022-02-12 15:24:00 +01:00
Benjamin Kramer
a9dcbcfe9f Use AffineMap::getSliceMap where applicable. NFCI. 2022-02-12 14:22:05 +01:00
Benjamin Kramer
6635c12ada [mlir] Use SmallBitVector instead of SmallDenseSet for AffineMap::compressSymbols
This is both more efficient and more ergonomic to use, as inverting a
bit vector is trivial while inverting a set is annoying.

Sadly this leaks into a bunch of APIs downstream, so adapt them as well.

This would be NFC, but there is an ordering dependency in MemRefOps's
computeMemRefRankReductionMask. This is now deterministic, previously it
was dependent on SmallDenseSet's unspecified iteration order.

Differential Revision: https://reviews.llvm.org/D119076
2022-02-07 00:21:44 +01:00
Mehdi Amini
e4853be2f1 Apply clang-tidy fixes for performance-for-range-copy to MLIR (NFC) 2022-01-02 22:19:56 +00:00
Mehdi Amini
1fc096af1e Apply clang-tidy fixes for performance-unnecessary-value-param to MLIR (NFC)
Reviewed By: Mogball

Differential Revision: https://reviews.llvm.org/D116250
2022-01-02 01:45:18 +00:00
Mehdi Amini
02b6fb218e Fix clang-tidy issues in mlir/ (NFC)
Reviewed By: ftynse

Differential Revision: https://reviews.llvm.org/D115956
2021-12-20 20:25:01 +00:00
Mehdi Amini
be0a7e9f27 Adjust "end namespace" comment in MLIR to match new agree'd coding style
See D115115 and this mailing list discussion:
https://lists.llvm.org/pipermail/llvm-dev/2021-December/154199.html

Differential Revision: https://reviews.llvm.org/D115309
2021-12-08 06:05:26 +00:00
Arnab Dutta
c2280b5517 [MLIR] Avoid creation of buggy affine maps when incorrect values of number of dimensions and number of symbols are provided.
We check whether the maximum index of dimensional identifier present
in the result expressions is less than dimCount (number of dimensional
identifiers) argument passed in the AffineMap::get() and the maximum index
of symbolic identifier present in the result expressions is less than
symbolCount (number of symbolic identifiers) argument passed in AffineMap::get().

Reviewed By: nicolasvasilache, bondhugula

Differential Revision: https://reviews.llvm.org/D114238
2021-11-27 00:37:08 +05:30
Diego Caballero
5c1d356c18 [mlir][Linalg] Enable vectorization of explicit broadcasts
This patch teaches `isProjectedPermutation` and `inverseAndBroadcastProjectedPermutation`
utilities to deal with maps representing an explicit broadcast, e.g., (d0, d1) -> (d0, 0).
This extension is needed to enable vectorization of such explicit broadcast in Linalg.

Reviewed By: pifon2a, nicolasvasilache

Differential Revision: https://reviews.llvm.org/D111563
2021-10-12 21:08:22 +00:00
Aart Bik
a643bd3189 [mlir] add permutation utility
I found myself typing this code several times at different places
by now, so time to make this a general utility instead. Given
a permutation, it returns the permuted position of the input,
for example (i,j,k) -> (k,i,j) yields position 1 for input 0.

Reviewed By: ftynse

Differential Revision: https://reviews.llvm.org/D108347
2021-08-24 08:07:40 -07:00
Nicolas Vasilache
7b47de774f [mlir] NFC - Add AffineMap::replace variant with dim/symbol inference 2021-07-14 20:29:12 +00:00
Stephan Herhut
884a6291f0 [mlir][linalg] Add scalar operands inlining pattern
This pattern inlines operands to a linalg.generic operation that use a constant
index and hence are loop-invariant scalars. This reduces the number of
linalg.generic operands and unlocks some canonicalizations that rely on seeing
an explicit tensor.extract.

Differential Revision: https://reviews.llvm.org/D102682
2021-05-21 15:23:28 +02:00
thomasraoux
9621c1ef56 [mlir][linalg] Fix vectorization bug in vector transfer indexing map calculation
The current implementation had a bug as it was relying on the target vector
dimension sizes to calculate where to insert broadcast. If several dimensions
have the same size we may insert the broadcast on the wrong dimension. The
correct broadcast cannot be inferred from the type of the source and
destination vector.

Instead when we want to extend transfer ops we calculate an "inverse" map to the
projected permutation and insert broadcast in place of the projected dimensions.

Differential Revision: https://reviews.llvm.org/D101738
2021-05-03 12:16:38 -07:00
Alex Zinenko
6841e6afba [mlir] support max/min lower/upper bounds in affine.parallel
This enables to express more complex parallel loops in the affine framework,
for example, in cases of tiling by sizes not dividing loop trip counts perfectly
or inner wavefront parallelism, among others. One can't use affine.max/min
and supply values to the nested loop bounds since the results of such
affine.max/min operations aren't valid symbols. Making them valid symbols
isn't an option since they would introduce selection trees into memref
subscript arithmetic as an unintended and undesired consequence. Also
add support for converting such loops to SCF. Drop some API that isn't used in
the core repo from AffineParallelOp since its semantics becomes ambiguous in
presence of max/min bounds. Loop normalization is currently unavailable for
such loops.

Depends On D101171

Reviewed By: bondhugula

Differential Revision: https://reviews.llvm.org/D101172
2021-04-29 13:16:25 +02:00