4 Commits

Author SHA1 Message Date
Matthias Springer
ffdbecccaf [mlir][bufferization] Add bufferization.alloc_tensor op
This change adds a new op `alloc_tensor` to the bufferization dialect. During bufferization, this op is always lowered to a buffer allocation (unless it is "eliminated" by a pre-processing pass). It is useful to have such an op in tensor land, because it allows users to model tensor SSA use-def chains (which drive bufferization decisions) and because tensor SSA use-def chains can be analyzed by One-Shot Bufferize, while memref values cannot.

This change also replaces all uses of linalg.init_tensor in bufferization-related code with bufferization.alloc_tensor.

linalg.init_tensor and bufferization.alloc_tensor are similar, but the purpose of the former one is just to carry a shape. It does not indicate a memory allocation.

linalg.init_tensor is not suitable for modelling SSA use-def chains for bufferization purposes, because linalg.init_tensor is marked as not having side effects (in contrast to alloc_tensor). As such, it is legal to move linalg.init_tensor ops around/CSE them/etc. This is not desirable for alloc_tensor; it represents an explicit buffer allocation while still in tensor land and such allocations should not suddenly disappear or get moved around when running the canonicalizer/CSE/etc.

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Differential Revision: https://reviews.llvm.org/D126003
2022-05-21 02:47:32 +02:00
Matthias Springer
f287da8a15 [mlir][bufferize] Better user control of layout maps
This changes replaces the `fully-dynamic-layout-maps` options (which was badly named) with two new options:

* `unknown-type-conversion` controls the layout maps on buffer types for which no layout map can be inferred.
* `function-boundary-type-conversion` controls the layout maps on buffer types inside of function signatures.

Differential Revision: https://reviews.llvm.org/D125615
2022-05-16 18:06:13 +02:00
Matthias Springer
d6dab38ae4 [mlir][bufferize][NFC] Add function boundary bufferization flag to BufferizationOptions
This makes the API easier to use. Also allows us to check for incorrect API usage for easier debugging.

Differential Revision: https://reviews.llvm.org/D124265
2022-04-23 01:11:37 +09:00
Matthias Springer
e07a7fd5c0 [mlir][bufferization] Move ModuleBufferization to bufferization dialect
* Move Module Bufferization to the bufferization dialect. The implementation is split into `OneShotModuleBufferize.cpp` and `FuncBufferizableOpInterfaceImpl.cpp`, so that the external model implementation can be easily moved to the func dialect in the future.
* Split and clean up test cases. A few test cases are still remaining in Linalg and will be updated separately.
* `linalg.inplaceable` is renamed to `bufferization.writable` to accurately reflect its current usage.
* Attributes and their verifiers are moved from the Linalg dialect to the Bufferization dialect.
* Expand documentation.
* Add a new flag to One-Shot Bufferize to allow for function boundary bufferization.

Differential Revision: https://reviews.llvm.org/D122229
2022-04-22 19:37:28 +09:00