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.
`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>
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
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
* 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`).
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.
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.
`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.
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
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
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
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
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
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
Small change to support projected permutations in the
`getPermutedPosition` utility. Renamed to `getResultPosition`.
Reviewed By: nicolasvasilache
Differential Revision: https://reviews.llvm.org/D138946
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
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
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
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
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
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
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
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
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