This commit adds the `BufferViewFlowOpInterface` to the bufferization
dialect. This interface can be implemented by ops that operate on
buffers to indicate that a buffer op result and/or region entry block
argument may be the same buffer as a buffer operand (or a view thereof).
This interface is queried by the `BufferViewFlowAnalysis`.
The new interface has two interface methods:
* `populateDependencies`: Implementations use the provided callback to
declare dependencies between operands and op results/region entry block
arguments. E.g., for `%r = arith.select %c, %m1, %m2 : memref<5xf32>`,
the interface implementation should declare two dependencies: %m1 -> %r
and %m2 -> %r.
* `mayBeTerminalBuffer`: An SSA value is a terminal buffer if the buffer
view flow analysis stops at the specified value. E.g., because the value
is a newly allocated buffer or because no further information is
available about the origin of the buffer.
Ops that implement the `RegionBranchOpInterface` or `BranchOpInterface`
do not have to implement the `BufferViewFlowOpInterface`. The buffer
dependencies can be inferred from those two interfaces.
This commit makes the `BufferViewFlowAnalysis` more accurate. For
unknown ops, it conservatively used to declare all combinations of
operands and op results/region entry block arguments as dependencies
(false positives). This is no longer the case. While the analysis is
still a "maybe" analysis with false positives (e.g., when analyzing ops
such as `arith.select` or `scf.if` where the taken branch is not known
at compile time), results and region entry block arguments of unknown
ops are now marked as terminal buffers.
This commit addresses a TODO in `BufferViewFlowAnalysis.cpp`:
```
// TODO: We should have an op interface instead of a hard-coded list of
// interfaces/ops.
```
It is no longer needed to hard-code ops.
This commit relaxes the assumption of type consistency for LLVM dialect
load and store operations in SROA. Instead, there is now a check that
loads and stores are in the bounds specified by the sub-slot they
access.
This commit additionally removes the corresponding patterns from the
type consistency pass, as they are no longer necessary.
Note: It will be necessary to extend Mem2Reg with the logic for
differently sized accesses as well. This is non-the-less a strict
upgrade for productive flows, as the type consistency pass can produce
invalid IR for some odd cases.
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.
This commit expends the Mem2Reg and SROA interface methods with passed
in handles to a `DataLayout` structure. This is done to avoid
superfluous retreiving of data layouts during each conversion of
intrinsics.
This change, additionally, enables subsequent changes to make the LLVM
dialect implementation of these interfaces type agnostic.
This PR adds promised interface declarations for all interfaces declared
in `InitAllDialects.h`.
Promised interfaces allow a dialect to declare that it will have an
implementation of a particular interface, crashing the program if one
isn't provided when the interface is used.
The current canonicalization of `memref.dim` operating on the result of
`memref.reshape` into `memref.load` is incorrect as it doesn't check
whether the `index` operand of `memref.dim` dominates the source
`memref.reshape` op. It always introduces `memref.load` right after
`memref.reshape` to ensure the `memref` is not mutated before the
`memref.load` call. As a result, the following error is observed:
```
$> mlir-opt --canonicalize input.mlir
func.func @reshape_dim(%arg0: memref<*xf32>, %arg1: memref<?xindex>, %arg2: index) -> index {
%c4 = arith.constant 4 : index
%reshape = memref.reshape %arg0(%arg1) : (memref<*xf32>, memref<?xindex>) -> memref<*xf32>
%0 = arith.muli %arg2, %c4 : index
%dim = memref.dim %reshape, %0 : memref<*xf32>
return %dim : index
}
```
results in:
```
dominator.mlir:22:12: error: operand #1 does not dominate this use
%dim = memref.dim %reshape, %0 : memref<*xf32>
^
dominator.mlir:22:12: note: see current operation: %1 = "memref.load"(%arg1, %2) <{nontemporal = false}> : (memref<?xindex>, index) -> index
dominator.mlir:21:10: note: operand defined here (op in the same block)
%0 = arith.muli %arg2, %c4 : index
```
Properly fixing this issue requires a dominator analysis which is
expensive to run within a canonicalization pattern. So, this patch fixes
the canonicalization pattern by being more strict/conservative about the
legality condition in which we perform this canonicalization.
The more general pattern is also added to `tensor.dim`. Since tensors are
immutable we don't need to worry about where to introduce the
`tensor.extract` call after canonicalization.
Before: op verifiers failed if the input and output ranks were the same
(i.e. no expansion or collapse). This behavior requires users of these
shape ops to verify manually that they are not creating identity
versions of these ops every time they build them -- problematic. This PR
removes this strict verification, and introduces folders for the the
identity cases.
The PR also removes the special case handling of rank-0 tensors for
expand_shape and collapse_shape, there doesn't seem to be any reason to
treat them differently.
When creating a new block in (conversion) rewrite patterns,
`OpBuilder::createBlock` must be used. Otherwise, no
`notifyBlockInserted` notification is sent to the listener.
Note: The dialect conversion relies on listener notifications to keep
track of IR modifications. Creating blocks without the builder API can
lead to memory leaks during rollback.
The `memref.subview` verifier currently checks result shape, element type, memory space and offset of the result type. However, the strides of the result type are currently not verified. This commit adds verification of result strides for non-rank reducing ops and fixes invalid IR in test cases.
Verification of result strides for ops with rank reductions is more complex (and there could be multiple possible result types). That is left for a separate commit.
Also refactor the implementation a bit:
* If `computeMemRefRankReductionMask` could not compute the dropped dimensions, there must be something wrong with the op. Return `FailureOr` instead of `std::optional`.
* `isRankReducedMemRefType` did much more than just checking whether the op has rank reductions or not. Inline the implementation into the verifier and add better comments.
* `produceSubViewErrorMsg` does not have to be templatized.
* Fix comment and add additional assert to `ExpandStridedMetadata.cpp`, to make sure that the memref.subview verifier is in sync with the memref.subview -> memref.reinterpret_cast lowering.
Note: This change is identical to #79865, but with a fixed comment and an additional assert in `ExpandStridedMetadata.cpp`. (I reverted #79865 in #80116, but the implementation was actually correct, just the comment in `ExpandStridedMetadata.cpp` was confusing.)
Reverts llvm/llvm-project#79865
I think there is a bug in the stride computation in
`SubViewOp::inferResultType`. (Was already there before this change.)
Reverting this commit for now and updating the original pull request
with a fix and more test cases.
The `memref.subview` verifier currently checks result shape, element
type, memory space and offset of the result type. However, the strides
of the result type are currently not verified. This commit adds
verification of result strides for non-rank reducing ops and fixes
invalid IR in test cases.
Verification of result strides for ops with rank reductions is more
complex (and there could be multiple possible result types). That is
left for a separate commit.
Also refactor the implementation a bit:
* If `computeMemRefRankReductionMask` could not compute the dropped
dimensions, there must be something wrong with the op. Return
`FailureOr` instead of `std::optional`.
* `isRankReducedMemRefType` did much more than just checking whether the
op has rank reductions or not. Inline the implementation into the
verifier and add better comments.
* `produceSubViewErrorMsg` does not have to be templatized.
This folded casts into `memref.transpose` without updating the result
type of the transpose op, which resulted in IR that failed to verify for
statically sized memrefs.
i.e.
```mlir
%cast = memref.cast %0 : memref<?x4xf32> to memref<?x?xf32>
%transpose = memref.transpose %cast : memref<?x?xf32> to memref<?x?xf32>
```
would fold to:
```mlir
// Fails verification:
%transpose = memref.transpose %cast : memref<?x4xf32> to memref<?x?xf32>
```
This commit renames 4 pattern rewriter API functions:
* `updateRootInPlace` -> `modifyOpInPlace`
* `startRootUpdate` -> `startOpModification`
* `finalizeRootUpdate` -> `finalizeOpModification`
* `cancelRootUpdate` -> `cancelOpModification`
The term "root" is a misnomer. The root is the op that a rewrite pattern
matches against
(https://mlir.llvm.org/docs/PatternRewriter/#root-operation-name-optional).
A rewriter must be notified of all in-place op modifications, not just
in-place modifications of the root
(https://mlir.llvm.org/docs/PatternRewriter/#pattern-rewriter). The old
function names were confusing and have contributed to various broken
rewrite patterns.
Note: The new function names use the term "modify" instead of "update"
for consistency with the `RewriterBase::Listener` terminology
(`notifyOperationModified`).
Currently, the `memref.transpose` verifier forces the result type of the
Op to have an explicit `StridedLayoutAttr` via the method
`inferTransposeResultType`. This means that the example Op
given in the documentation is actually invalid because it uses an `AffineMap`
to specify the layout.
It also means that we can't "un-transpose" a transposed memref back to
the implicit layout form, because the verifier will always enforce the
explicit strided layout.
This patch makes the following changes:
1. The verifier checks whether the canonicalized strided layout of the
result Type is identitcal to the canonicalized infered result type
layout. This way, it's only important that the two Types have the same
strided layout, not necessarily the same representation of it.
2. The folder is extended to support folding away the trivial case of
identity permutation and to fold one transposition into another by
composing the permutation maps.
This PR adds promised interface declarations for
`ConvertToLLVMPatternInterface` in all the dialects that support the
`ConvertToLLVM` dialect extension.
Promised interfaces allow a dialect to declare that it will have an
implementation of a particular interface, crashing the program if one
isn't provided when the interface is used.
This change adds (runtime) bounds checks for `memref` ops using the
existing `RuntimeVerifiableOpInterface`. For `memref.load` and
`memref.store`, we check that the indices are in-bounds of the memref's
index space. For `memref.reinterpret_cast` and `memref.subview` we check
that the resulting address space is in-bounds of the input memref's
address space.
Fixes https://github.com/llvm/llvm-project/issues/71326.
The cause of the issue was that a new `LoadOp` was created which looked
something like:
```mlir
%arg4 =
func.func main(%arg1 : index, %arg2 : index) {
%alloca_0 = memref.alloca() : memref<vector<1x32xi1>>
%1 = vector.type_cast %alloca_0 : memref<vector<1x32xi1>> to memref<1xvector<32xi1>>
%2 = memref.load %1[%arg1, %arg2] : memref<1xvector<32xi1>>
return
}
```
which crashed inside the `LoadOp::verify`. Note here that `%alloca_0` is
0 dimensional, `%1` has one dimension, but `memref.load` tries to index
`%1` with two indices.
This is now fixed by using the fact that `unpackOneDim` always unpacks
one dim
1bce61e6b0/mlir/lib/Conversion/VectorToSCF/VectorToSCF.cpp (L897-L903)
and so the `loadOp` should just index only one dimension.
---------
Co-authored-by: Benjamin Maxwell <macdue@dueutil.tech>
This adds an operation for concatenating ranked tensors along a static
dimension, as well as a decomposition mirroring the existing lowering
from TOSA to Tensor. This offers a convergence point for "input" like
dialects that include various lowerings for concatenation operations,
easing later analysis. In the future, this op can implement the
necessary interfaces for tiling, as well as potentially add conversions
to some kind of linalg and/or memref counterpart.
This patch adds the op, the decomposition, and some basic
folding/canonicalization. Replacing lowerings with the op (such as the
TOSA lowering) will come as a follow up.
See
https://discourse.llvm.org/t/rfc-tensor-add-a-tensor-concatenate-operation/74858
This adds a conversion for narrow type emulation of memref.store ops.
The conversion replaces the memref.store with two memref.atomic_rmw ops.
Atomics are used to prevent race conditions on same-byte accesses, in
the event that two threads are storing into the same byte.
Fixes https://github.com/openxla/iree/issues/15370
In #71153, the `memref.subview` canonicalizer crashes due to a negative
`size` being passed as an operand. During `SubViewOp::verify` this
negative `size` is not yet detectable since it is dynamic and only
available after constant folding, which happens during the
canonicalization passes. As discussed in
<https://discourse.llvm.org/t/rfc-more-opfoldresult-and-mixed-indices-in-ops-that-deal-with-shaped-values/72510>,
the verifier should not be extended as it should "only verify local
aspects of an operation".
This patch fixes#71153 by not folding in aforementioned situation.
Also, this patch adds a basic offset and size check in the
`OffsetSizeAndStrideOpInterface` verifier.
Note: only `offset` and `size` are checked because `stride` is allowed
to be negative
(54d81e49e3).
This patch fixes two checks where a `SmallBitVector` containing the
potential dropped dims of a SubView/ExtractSlice operation was queried
via `empty()` instead of `none()`.
The contents of a mask on a masked transfer are unaffected by the
particular region of memory being read/stored to, so just forward the
mask in subview folding patterns.
Fixes#70902.
The out of bounds check in the SROA implementation for MemRef was not
actually testing anything because it only operated on a store op which
does not trigger the logic by itself. It is now checked for real and the
underlying bug is fixed.
I checked the LLVM implementation just in case but this should not
happen as out-of-bound checks happen in GEP's verifier there.
`bufferization.materialize_in_destination` should be used instead. Both
ops bufferize to a memcpy. This change also conceptually cleans up the
memref dialect a bit: the memref dialect no longer contains ops that
operate on tensor values.
/llvm-project/mlir/lib/Dialect/MemRef/Transforms/ResolveShapedTypeResultDims.cpp:98:19: error: comparison of integers of different signs: 'value_type' (aka 'long long') and 'size_t' (aka 'unsigned long') [-Werror,-Wsign-compare]
if (*dimIndex >= reifiedResultShapes[resultNumber].size())
~~~~~~~~~ ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Do not crash when the input IR is invalid, i.e., when the index of the
dimension operand of a `tensor.dim`/`memref.dim` is out-of-bounds. This
fixes#70180.
The `resolveSourceIndicesCollapseShape` method is used to compute
indices into the source `MemRef` of a `CollapseShapeOp` from the
collapsed indices. This method didn't check for dynamic sizes of the
source shape which led to a crash.
Fix https://github.com/llvm/llvm-project/issues/68483
This patch fixes strided memref offset calculation for emulating narrow
types.
As a side effect, this patch also adds support for a 1-D subviews with
static sizes, static offsets and strides of 1 for testing. Emulate
narrow types pass was not tested for strided memrefs before this patch.
…st)`
`expand-strided-metadata` was missing a pattern to get rid of
`memref.cast`.
The pattern is straight foward:
Produce a new `extract_strided_metadata` with the source of the cast and
fold the static information (sizes, strides, offset) along the way.
This PR adds a new transform op that replaces `memref.alloca`s with
`memref.get_global`s to newly inserted `memref.global`s. This is useful,
for example, for allocations that should reside in the shared memory of
a GPU, which have to be declared as globals.
This commit implements `LoopLikeOpInterface` on `scf.while`. This
enables LICM (and potentially other transforms) on `scf.while`.
`LoopLikeOpInterface::getLoopBody()` is renamed to `getLoopRegions` and
can now return multiple regions.
Also fix a bug in the default implementation of
`LoopLikeOpInterface::isDefinedOutsideOfLoop()`, which returned "false"
for some values that are defined outside of the loop (in a nested op, in
such a way that the value does not dominate the loop). This interface is
currently only used for LICM and there is no way to trigger this bug, so
no test is added.
