Instead just emit a warning that analysis failed and the result will be treated conservatively.
Differential Revision: https://reviews.llvm.org/D111217
These are considered noops.
Buferization will still fail on scf.execute_region which yield values.
This is used to make comprehensive bufferization interoperate better with external clients.
Differential Revision: https://reviews.llvm.org/D111130
This change allows better interop with external clients of comprehensive bufferization functions
but is otherwise NFC for the MLIR pass itself.
Differential Revision: https://reviews.llvm.org/D111121
This revision exposes some minimal funcitonality to allow comprehensive
bufferization to interop with external projects.
Differential Revision: https://reviews.llvm.org/D110875
It was previously assumed that tensor.insert_slice should be bufferized first in a greedy fashion to avoid out-of-place bufferization of the large tensor. This heuristic does not hold upon further inspection.
This CL removes the special handling of such ops and adds a test that exhibits better behavior and appears in real use cases.
The only test adversely affected is an artificial test which results in a returned memref: this pattern is not allowed by comprehensive bufferization in real scenarios anyway and the offending test is deleted.
Differential Revision: https://reviews.llvm.org/D110072
Previously, comprehensive bufferize would consider all aliasing reads and writes to
the result buffer and matching operand. This resulted in spurious dependences
being considered and resulted in too many unnecessary copies.
Instead, this revision revisits the gathering of read and write alias sets.
This results in fewer alloc and copies.
An exhaustive test cases is added that considers all possible permutations of
`matmul(extract_slice(fill), extract_slice(fill), ...)`.
This revision fixes a corner case that could appear due to incorrect insertion point behavior in comprehensive bufferization.
Differential Revision: https://reviews.llvm.org/D109830
AliasInfo can now use union-find for a much more efficient implementation.
This brings no functional changes but large performance gains on more complex examples.
Differential Revision: https://reviews.llvm.org/D109819
This revision allows hoisting static alloc/dealloc pairs as high as possible during ComprehensiveBufferization.
This also aligns such allocated buffers to 128B by default.
This change exhibited some issues wrt insertion points and a missing copy that are also fixed in this revision; tests are updated accordingly.
Differential Revision: https://reviews.llvm.org/D109684
This revision fixes the traversal order of extract_slice during the inplace analysis.
It was previously thought that such ops could be analyzed at the very end.
This is unfortunately not true as the AliasInfo for dependents of these ops need to be updated.
This change allows the aliases introduced by the bufferization of extract_slice to be properly propagated.
Differential Revision: https://reviews.llvm.org/D109519
Change the formatting of the debug print outs to elide unnecessary information.
Reviewed By: nicolasvasilache
Differential Revision: https://reviews.llvm.org/D106661
Historically the builtin dialect has had an empty namespace. This has unfortunately created a very awkward situation, where many utilities either have to special case the empty namespace, or just don't work at all right now. This revision adds a namespace to the builtin dialect, and starts to cleanup some of the utilities to no longer handle empty namespaces. For now, the assembly form of builtin operations does not require the `builtin.` prefix. (This should likely be re-evaluated though)
Differential Revision: https://reviews.llvm.org/D105149
When the source tensor of a tensor.insert_slice is not equivalent to an inplace buffer an extra copy is necessary. This revision adds the missing copy.
Reviewed By: gysit
Differential Revision: https://reviews.llvm.org/D106587
Bufferization handles all unknown ops conservative. The patch ensures accessing the dimension of an output tensor does not prevent in place bufferization.
Reviewed By: nicolasvasilache
Differential Revision: https://reviews.llvm.org/D106356
Clean up corner cases related to elemental tensor / buffer type return values that would previously fail.
Reviewed By: ThomasRaoux
Differential Revision: https://reviews.llvm.org/D105857
Previously, linalg bufferization always had to be conservative at function boundaries and assume the most dynamic strided memref layout.
This revision introduce the mechanism to specify a linalg.buffer_layout function argument attribute that carries an affine map used to set a less pessimistic layout.
Reviewed By: ThomasRaoux
Differential Revision: https://reviews.llvm.org/D105859
Previously, comprehensive bufferization of scf.yield did not have enough information
to detect whether an enclosing scf::for bbargs would bufferize to a buffer equivalent
to that of the matching scf::yield operand.
As a consequence a separate sanity check step would be required to determine whether
bufferization occured properly.
This late check would miss the case of calling a function in an loop.
Instead, we now pass and update aliasInfo during bufferization and it is possible to
imrpove bufferization of scf::yield and drop that post-pass check.
Add an example use case that was failing previously.
This slightly modifies the error conditions, which are also updated as part of this
revision.
Differential Revision: https://reviews.llvm.org/D105803
Add the rewrite of PadTensorOp to InitTensor + InsertSlice before the
bufferization analysis starts.
This is exercised via a more advanced integration test.
Since the new behavior triggers folding, 2 tests need to be updated.
One of those seems to exhibit a folding issue with `switch` and is modified.
Differential Revision: https://reviews.llvm.org/D105549
The `bufferizesToMemoryRead` condition was too optimistics in the case
of operands that map to a block argument.
This is the case for ForOp and TiledLoopOp.
For such ops, forward the call to all uses of the matching BBArg.
Differential Revision: https://reviews.llvm.org/D105540
Remove `getDynOperands` and `createOrFoldDimOp` from MemRef.h to decouple MemRef a bit from Tensor. These two functions are used in other dialects/transforms.
Differential Revision: https://reviews.llvm.org/D105260
ConstantOp are only supported in the ModulePass because they require a GlobalCreator object that must be constructed from a ModuleOp.
If the standlaone FunctionPass encounters a ConstantOp, bufferization fails.
Differential revision: https://reviews.llvm.org/D105156
This revision drops the comprehensive bufferization Function pass, which has issues when trying to bufferize constants.
Instead, only support the comprehensive-module-bufferize by default.
Differential Revision: https://reviews.llvm.org/D105228
Also add an integration test that connects all the dots end to end, including with cast to unranked tensor for external library calls.
Differential Revision: https://reviews.llvm.org/D105106
Cross function boundary bufferization support is added.
This is enabled by cross-function boundary alias analysis, for which the bufferization process is extended: it can now modify the BufferizationAliasInfo as new ops are introduced.
A number of simplifying assumptions are made:
1. by default we bufferize to the most dynamic strided memref type, further memref::CastOp canonicalizations are expected to clean up the IR.
2. in the current implementation, the stride information is always erased at function boundaries. A subsequent pass will be required to analyze the meet of all call ops to a function and decide whether more static buffer types can be used. This will potentially clone functions when it is deemed profitable to do so (e.g. when the stride-1 dimension may vary).
3. external function always bufferize to the most dynamic strided memref version. This may require special annotations for specifying that particular operands of top-level functions have contiguous buffer layout.
An alternative to point 3. would be to support tensor layout annotations, which is currently not supported in MLIR.
Differential revision: https://reviews.llvm.org/D104873
* Split memref.dim into two operations: memref.dim and tensor.dim. Both ops have the same builder interface and op argument names, so that they can be used with templates in patterns that apply to both tensors and memrefs (e.g., some patterns in Linalg).
* Add constant materializer to TensorDialect (needed for folding in affine.apply etc.).
* Remove some MemRefDialect dependencies, make some explicit.
Differential Revision: https://reviews.llvm.org/D105165
This revision adds the minimal plumbing to create a simple ComprehensiveModuleBufferizePass that can behave conservatively in the presence of CallOps.
A topological sort of caller/callee is performed and, if the call-graph is cycle-free, analysis can proceed.
Differential revision: https://reviews.llvm.org/D104859
The case where a non-dominating read can be found is captured by slightly generalizing `AliasInfo::wouldCreaateReadAfterWriteInterference`.
This simplification will make it easier to implement bufferization across function call.
APIs are also simplified were possible.
Differential revision: https://reviews.llvm.org/D104845
Adapt the StructuredOp verifier to ensure all operands are either in the input or the output group. The change is possible after adding support for scalar input operands (https://reviews.llvm.org/D104220).
Differential Revision: https://reviews.llvm.org/D104783
Reduce code duplication: Move various helper functions, that are duplicated in TensorDialect, MemRefDialect, LinalgDialect, StandardDialect, into a new StaticValueUtils.cpp.
Differential Revision: https://reviews.llvm.org/D104687
scf::ForOp bufferization analysis proceeds just like for any other op (including FuncOp) at its boundaries; i.e. if:
1. The tensor operand is inplaceable.
2. The matching result has no subsequent read (i.e. all reads dominate the scf::ForOp).
3. In and does not create a RAW interference.
then it can bufferize inplace.
Still there are a few differences:
1. bbArgs for an scf::ForOp are always considered inplaceable when seen from ops inside the body. This is because a) either the matching tensor operand is not inplaceable and an alloc will be inserted (which makes bbArg itself inplaceable); or b) the tensor operand and bbArg are both already inplaceable.
2. Bufferization within the scf::ForOp body has implications to the outside world : the scf.yield terminator may well ping-pong values of the same type. This muddies the water for alias analysis and is not supported atm. Such cases result in a pass failure.
Differential revision: https://reviews.llvm.org/D104490
The main goal of this commit is to remove the dependency of Standard dialect on the Tensor dialect.
* Rename SubTensorOp -> tensor.extract_slice, SubTensorInsertOp -> tensor.insert_slice.
* Some helper functions are (already) duplicated between the Tensor dialect and the MemRef dialect. To keep this commit smaller, this will be cleaned up in a separate commit.
* Additional dialect dependencies: Shape --> Tensor, Tensor --> Standard
* Remove dialect dependencies: Standard --> Tensor
* Move canonicalization test cases to correct dialect (Tensor/MemRef).
Note: This is a fixed version of https://reviews.llvm.org/D104499, which was reverted due to a missing update to two CMakeFile.txt.
Differential Revision: https://reviews.llvm.org/D104676
The main goal of this commit is to remove the dependency of Standard dialect on the Tensor dialect.
* Rename ops: SubTensorOp --> ExtractTensorOp, SubTensorInsertOp --> InsertTensorOp
* Some helper functions are (already) duplicated between the Tensor dialect and the MemRef dialect. To keep this commit smaller, this will be cleaned up in a separate commit.
* Additional dialect dependencies: Shape --> Tensor, Tensor --> Standard
* Remove dialect dependencies: Standard --> Tensor
* Move canonicalization test cases to correct dialect (Tensor/MemRef).
Differential Revision: https://reviews.llvm.org/D104499
This revision adds a BufferizationAliasInfo which maintains and updates information about which tensors will alias once bufferized, which bufferized tensors are equivalent to others and how to handle clobbers.
Bufferization greedily tries to bufferize inplace by:
1. first trying to bufferize SubTensorInsertOp inplace, in reverse order (these are deemed the most expensives).
2. then trying to bufferize all non SubTensorOp / SubTensorInsertOp, in reverse order.
3. lastly trying to bufferize all SubTensorOp in reverse order.
Reverse order is a heuristic that seems to work nicely because structured tensor codegen very often proceeds by:
1. take a subset of a tensor
2. compute on that subset
3. insert the result subset into the full tensor and yield a new tensor.
BufferizationAliasInfo + equivalence sets + clobber analysis allows bufferizing nested
subtensor/compute/subtensor_insert sequences inplace to a certain extent.
To fully realize inplace bufferization, additional container-containee analysis will be necessary and is left for a subsequent commit.
Differential revision: https://reviews.llvm.org/D104110
Up to now all structured op operands are assumed to be shaped. The patch relaxes this assumption and allows scalar input operands. In contrast to shaped operands scalar operands are not indexed and directly forwarded to the body of the operation. As all other operands, scalar operands are associated to an indexing map that in case of a scalar or a 0D-operand has an empty range.
We will use scalar operands as a replacement for the capture mechanism. In contrast to captures, the approach ensures we can generate the function signature from the operand list and it prevents outdated capture values in case a transformation updates only the capture operand but not the hidden body of a named operation.
Removing captures and updating existing operations such as linalg.fill is left for a later patch.
The patch depends on https://reviews.llvm.org/D103891 and https://reviews.llvm.org/D103890.
Differential Revision: https://reviews.llvm.org/D104109
This revision refactors and simplifies the pattern detection logic: thanks to SSA value properties, we can actually look at all the uses of a given value and avoid having to pattern-match specific chains of operations.
A bufferization pattern for subtensor is added and specific inplaceability analysis is implemented for the simple case of subtensor. More advanced use cases will follow.
Differential revision: https://reviews.llvm.org/D102512
