Files
clang-p2996/mlir/lib/Dialect/Tensor/Transforms/SwapExtractSliceWithProducerPatterns.cpp
Mahesh Ravishankar 809e3d8c98 [mlir][TilingInterface] Modify TilingInterface methods to better return the state of the transformed IR.
Currently the `getTiledImplementation` and `generateResultTileValue`
return just `SmallVector<Operation *>` and `FailureOr<Value>`.

- For `getTiledImplementation` returning empty implies tiling wasnt
  done. There is also an implicit assumption that the tiled operation
  results correspond to the tiled values of the result of the original
  operation. This cannot handle cases where the tiled implementation
  might use multiple operations to compute the tiled value for the
  results of the untiled operation. Sometimes, the tiled operation
  might not directly give the tiled values, and might require casts,
  etc to get a replacement.
- For `generateResultTileValue`, it is assumed that the op defining
  the returned `Value` is the operation that represents the tiled
  computation. Again presence of casts, etc violate this.

Instead make these methods return
```
struct TilingResult {
  SmallVector<Operation *> tiledOps;
  SmallVector<Value> tiledValues;
};
```

The `tiledOps` represent the operations generated that are relevant
for subsequent transformations. The `tiledValues` represent the tiled
values for the results of the original operation. This better
transmits the state of the transformed IR.

As a consequence the following methods also return `FailureOr<TilingResult>`
- `tensor::replaceExtractSliceWithTiledProducer`
- `tensor::bubbleUpPadSlice`

Differential Revision: https://reviews.llvm.org/D145133
2023-03-16 14:29:03 +00:00

43 lines
1.6 KiB
C++

//===- SwapExtractSliceWithProducerPatterns.cpp ---------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// Swap a `tensor.extract_slice` with the producer of the source if the producer
// implements the `TilingInterface`. When used in conjunction with tiling this
// effectively tiles + fuses the producer with its consumer.
//
//===----------------------------------------------------------------------===//
#include "mlir/Dialect/Arith/IR/Arith.h"
#include "mlir/Dialect/Tensor/IR/Tensor.h"
#include "mlir/Dialect/Tensor/Transforms/Transforms.h"
#include "mlir/Dialect/Utils/StaticValueUtils.h"
#include "mlir/Interfaces/TilingInterface.h"
using namespace mlir;
FailureOr<TilingResult> tensor::replaceExtractSliceWithTiledProducer(
OpBuilder &builder, tensor::ExtractSliceOp sliceOp, OpResult producer) {
auto producerOp = dyn_cast<TilingInterface>(producer.getOwner());
if (!producerOp)
return failure();
// `TilingInterface` currently only supports strides being 1.
if (llvm::any_of(sliceOp.getMixedStrides(), [](OpFoldResult ofr) {
return !isConstantIntValue(ofr, 1);
}))
return failure();
FailureOr<TilingResult> tiledResult = producerOp.generateResultTileValue(
builder, producer.getResultNumber(), sliceOp.getMixedOffsets(),
sliceOp.getMixedSizes());
if (failed(tiledResult))
return failure();
return *tiledResult;
}