7 Commits

Author SHA1 Message Date
Matthias Springer
c1fef4e88a [mlir][bufferization] Make TensorCopyInsertionPass a test pass
TensorCopyInsertion should not have been exposed as a pass. This was a flaw in the original design. It is a preparation step for bufferization and certain transforms (that would otherwise be legal) are illegal between TensorCopyInsertion and actual rewrite to MemRef ops. Therefore, even if broken down as two separate steps internally, they should be exposed as a single pass.

This change affects the sparse compiler, which uses `TensorCopyInsertionPass`. A new `SparsificationAndBufferizationPass` is added to replace all passes in the sparse tensor pipeline from `TensorCopyInsertionPass` until the actual bufferization (rewrite to memref/non-tensor). It is generally unsafe to run arbitrary passes in-between, in particular passes that hoist tensor ops out of loops or change SSA use-def chains along tensor ops.

Differential Revision: https://reviews.llvm.org/D138915
2022-12-02 15:38:02 +01:00
Lei Zhang
9bb633741a [mlir][bufferization] Support general Attribute as memory space
MemRef has been accepting a general Attribute as memory space for
a long time. This commits updates bufferization side to catch up,
which allows downstream users to plugin customized symbolic memory
space. This also eliminates quite a few `getMemorySpaceAsInt`
calls, which is deprecated.

Reviewed By: springerm

Differential Revision: https://reviews.llvm.org/D138330
2022-11-21 09:40:50 -05:00
Matthias Springer
c0b0b6a00a [mlir][bufferize] Infer memory space in all bufferization patterns
This change updates all remaining bufferization patterns (except for scf.while) and the remaining bufferization infrastructure to infer the memory space whenever possible instead of falling back to "0". (If a default memory space is set in the bufferization options, we still fall back to that value if the memory space could not be inferred.)

Differential Revision: https://reviews.llvm.org/D128423
2022-06-27 16:32:52 +02:00
Matthias Springer
3474d10e1a [mlir][bufferization][NFC] Make escape a dialect attribute
All bufferizable ops that bufferize to an allocation receive a `bufferization.escape` attribute during TensorCopyInsertion.

Differential Revision: https://reviews.llvm.org/D128137
2022-06-23 19:34:47 +02:00
Matthias Springer
a36c801d12 [mlir][bufferize] Better implementation of AnalysisState::isTensorYielded
If `create-deallocs=0`, mark all bufferization.alloc_tensor ops as escaping. (Unless they already have an `escape` attribute.) In the absence of analysis information, check SSA use-def chains to see if the value may be yielded.

Differential Revision: https://reviews.llvm.org/D127302
2022-06-15 10:15:47 +02:00
Matthias Springer
79f115911e [mlir][bufferize] Avoid tensor copies when the data is not read
There are various shortcuts in `BufferizationState::getBuffer` that avoid a buffer copy when we just need an allocation (and no initialization). This change adds those shortcuts to the TensorCopyInsertion pass, so that `getBuffer` can be simplified in a subsequent change.

Differential Revision: https://reviews.llvm.org/D126821
2022-06-10 10:26:07 +02:00
Matthias Springer
3b2004e16b [mlir][bufferization] Add TensorCopyInsertion pass
This pass runs the One-Shot Analysis to find out which tensor OpOperands must bufferize out-of-place. It then rewrites those tensor OpOperands to explicit allocations with a copy in the form of `bufferization.alloc_tensor`. The resulting IR can then be bufferized without having to care about read-after-write conflicts.

This change makes it possible to connect One-Shot Analysis to other bufferizations such as the sparse compiler.

Differential Revision: https://reviews.llvm.org/D126573
2022-06-09 21:55:52 +02:00