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[mlir][linalg] Fix and Refactor DecomposeOuterUnitDimsUnPackOpPattern #119379

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66 changes: 45 additions & 21 deletions mlir/lib/Dialect/Linalg/Transforms/Transforms.cpp
Original file line number Diff line number Diff line change
Expand Up @@ -1252,64 +1252,88 @@ LogicalResult DecomposeOuterUnitDimsUnPackOpPattern::matchAndRewrite(
"require the tiled outer dimensions of the result are all 1s");
}

// 1. Use rank-reduced tensor.extract_slice op to extract the tile.
// 1. Use rank-reduced tensor.extract_slice op to extract the tile:
// %extracted_tile = tensor.extract_slice(%unpack_op_input)
Location loc = unpackOp.getLoc();
Value source = unpackOp.getSource();
DenseMap<int64_t, OpFoldResult> dimAndTileMapping =
unpackOp.getDimAndTileMapping();
Attribute zeroIdxAttr = rewriter.getIndexAttr(0);
Attribute oneIdxAttr = rewriter.getIndexAttr(1);
SmallVector<OpFoldResult> readOffsets(srcRank, zeroIdxAttr);
SmallVector<OpFoldResult> readStrides(srcRank, oneIdxAttr);
SmallVector<OpFoldResult> readSizes;
SmallVector<int64_t> readShape;
SmallVector<Value> dynamicDims;

// The sizes, affset and strides attributes for ExtractSliceOp.
SmallVector<OpFoldResult> extractSliceSizes;
SmallVector<OpFoldResult> extractSliceOffsets(srcRank, zeroIdxAttr);
SmallVector<OpFoldResult> extractSliceStrides(srcRank, oneIdxAttr);
// The shape for ExtractSliceOp (due to rank-reducing, this is likely !=
// extractSliceSizes).
SmallVector<int64_t> readShapeForExtractSlice;

// Shape for EmptyOp that's used as the init value for TransposeOp below.
// This should match tile size + transposition.
SmallVector<OpFoldResult> shapeForEmptyOp;

for (auto i : llvm::seq<unsigned>(0, destRank)) {
// Given the assumption that all outer tiled dims are 1, the corresponding
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It's more than an assumption here, since we have the check above.

// slice size to read is also 1. As this will be rank-reducing "extract
// slice" (i.e. the unit dims will be "collapsed"), there's no need to
// update:
// * the output shape for ExtractSliceOp, nor
// * the shape for EmptyOp.
if (dimAndTileMapping.count(i)) {
readSizes.push_back(oneIdxAttr);
extractSliceSizes.push_back(oneIdxAttr);
continue;
}

// Compute sizes attribute for ExtractSliceOp + EmptyOp
if (ShapedType::isDynamic(srcShape[i])) {
Value dynamicDim =
OpFoldResult dynamicDim =
rewriter.create<tensor::DimOp>(loc, source, i).getResult();
readSizes.push_back(dynamicDim);
dynamicDims.push_back(dynamicDim);
extractSliceSizes.push_back(dynamicDim);
shapeForEmptyOp.push_back(dynamicDim);
} else {
readSizes.push_back(rewriter.getIndexAttr(srcShape[i]));
extractSliceSizes.push_back(rewriter.getIndexAttr(srcShape[i]));
if (srcShape[i] != 1)
shapeForEmptyOp.push_back(rewriter.getIndexAttr(srcShape[i]));
}
// Compute the output shape for ExtractSliceOp (take into account
// rank-reducing)
if (srcShape[i] != 1) {
readShapeForExtractSlice.push_back(srcShape[i]);
}
if (srcShape[i] != 1)
readShape.push_back(srcShape[i]);
}
auto mixedTiles = unpackOp.getMixedTiles();
readSizes.append(mixedTiles.begin(), mixedTiles.end());
// TODO: This effectively assumes that that tile sizes match the trailing
// sizes for ExtractSliceOp and EmptyOp - document this.
extractSliceSizes.append(mixedTiles.begin(), mixedTiles.end());
shapeForEmptyOp.append(mixedTiles.begin(), mixedTiles.end());

// Explicitly create the type for extract_slice op because the inner tile
// size could be 1. We want to represent the whole inner tile in this case.
auto tileShape = srcShape.drop_front(destRank);
// Append the inner tile shape to the permuted and rank-reduced outer shape.
readShape.append(tileShape.begin(), tileShape.end());
readShapeForExtractSlice.append(tileShape.begin(), tileShape.end());
Type elemType = unpackOp.getSourceType().getElementType();
auto readType = RankedTensorType::get(readShape, elemType);
auto readType = RankedTensorType::get(readShapeForExtractSlice, elemType);
Value innerTile = rewriter.create<tensor::ExtractSliceOp>(
loc, readType, unpackOp.getSource(), readOffsets, readSizes, readStrides);
loc, readType, unpackOp.getSource(), extractSliceOffsets,
extractSliceSizes, extractSliceStrides);

// 2. Transpose the tile to match the outer corresponding tile order.
SmallVector<int64_t> perm = getPackUnpackRankReducedPerm(
srcShape.take_front(destRank), innerDimsPos, unpackOp.getOuterDimsPerm());
// Unpack is a transition out of packed space so we invert the permutation.
perm = invertPermutationVector(perm);
SmallVector<int64_t> transpShape(readShape);
applyPermutationToVector<int64_t>(transpShape, perm);
applyPermutationToVector<OpFoldResult>(shapeForEmptyOp, perm);

Value empty =
rewriter.create<tensor::EmptyOp>(loc, transpShape, elemType, dynamicDims);
rewriter.create<tensor::EmptyOp>(loc, shapeForEmptyOp, elemType);
auto transposedOp =
rewriter.create<linalg::TransposeOp>(loc, innerTile, empty, perm);

// 3. Handle in-complete tiles if needed. It truncates trailing data from the
// transposed tile.
int numLoops = transpShape.size();
int numLoops = shapeForEmptyOp.size();
SmallVector<OpFoldResult> tileStrides(numLoops, oneIdxAttr);
SmallVector<OpFoldResult> tileOffsets(numLoops, zeroIdxAttr);
SmallVector<OpFoldResult> tileSizes;
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30 changes: 20 additions & 10 deletions mlir/test/Dialect/Linalg/decompose-tensor-unpack.mlir
Original file line number Diff line number Diff line change
Expand Up @@ -35,15 +35,15 @@ func.func @simple_unpack_static_tiles(%input: tensor<1x1x8x2xf32>, %output: tens

/// Same as example above, but with 1 dynamic tile size.

func.func @simple_unpack_dynamic_tile(%input: tensor<1x1x?x2xf32>, %output: tensor<5x1xf32>, %tile_dim_0: index) -> tensor<5x1xf32> {
%0 = tensor.unpack %input inner_dims_pos = [0, 1] inner_tiles = [%tile_dim_0, 2] into %output : tensor<1x1x?x2xf32> -> tensor<5x1xf32>
func.func @simple_unpack_dynamic_tile(%input: tensor<1x1x?x2xf32>, %output: tensor<5x1xf32>, %tile_dim: index) -> tensor<5x1xf32> {
%0 = tensor.unpack %input inner_dims_pos = [0, 1] inner_tiles = [%tile_dim, 2] into %output : tensor<1x1x?x2xf32> -> tensor<5x1xf32>
return %0 : tensor<5x1xf32>
}
// CHECK-LABEL: func.func @simple_unpack_dynamic_tile
// CHECK-SAME: %[[SRC:[a-zA-Z0-9]+]]
// CHECK-SAME: %[[DEST:[a-zA-Z0-9]+]]
// CHECK-SAME: %[[TILE_DIM_1:[a-zA-Z0-9]+]]
// CHECK: %[[TILE:.+]] = tensor.extract_slice %[[SRC]][0, 0, 0, 0] [1, 1, %[[TILE_DIM_1]], 2] [1, 1, 1, 1]
// CHECK-SAME: %[[TILE_DIM:[a-zA-Z0-9]+]]
// CHECK: %[[TILE:.+]] = tensor.extract_slice %[[SRC]][0, 0, 0, 0] [1, 1, %[[TILE_DIM]], 2] [1, 1, 1, 1]
// CHECK-NOT: linalg.transpose
// They have the same type, so the insert_slice op is folded
// away.
Expand All @@ -52,13 +52,23 @@ func.func @simple_unpack_dynamic_tile(%input: tensor<1x1x?x2xf32>, %output: tens

/// Same as example above, but with 1 dynamic tile size and a trasnpose

/// FIXME: This is currently broken:
/// * 'tensor.empty' op incorrect number of dynamic sizes, has 0, expected 1
func.func @simple_unpack_dynamic_tile_transpose(%src: tensor<1x1x2x?xf32>, %dest: tensor<5x1xf32>, %tile_dim: index) -> tensor<5x1xf32> {
%0 = tensor.unpack %src inner_dims_pos = [1, 0] inner_tiles = [2, %tile_dim] into %dest : tensor<1x1x2x?xf32> -> tensor<5x1xf32>
return %0 : tensor<5x1xf32>
}
// CHECK-LABEL: func.func @simple_unpack_dynamic_tile_transpose
// CHECK-SAME: %[[SRC:[a-zA-Z0-9]+]]
// CHECK-SAME: %[[DEST:[a-zA-Z0-9]+]]
// CHECK-SAME: %[[TILE_DIM:[a-zA-Z0-9]+]]
// CHECK: %[[TILE:.*]] = tensor.extract_slice %[[SRC]][0, 0, 0, 0] [1, 1, 2, %[[TILE_DIM]]] [1, 1, 1, 1] : tensor<1x1x2x?xf32> to tensor<2x?xf32>
// CHECK: %[[EMPTY:.*]] = tensor.empty(%[[TILE_DIM]]) : tensor<?x2xf32>
// CHECK: %[[TRANSP:.*]] = linalg.transpose
// CHECK-SAME: ins(%[[TILE]] : tensor<2x?xf32>)
// CHECK-SAME: outs(%[[EMPTY]] : tensor<?x2xf32>)
// CHECK-SAME: permutation = [1, 0]
// CHECK: %[[SLICE:.*]] = tensor.extract_slice %[[TRANSP]][0, 0] [5, 1] [1, 1] : tensor<?x2xf32> to tensor<5x1xf32>
// CHECK: return %[[SLICE]] : tensor<5x1xf32>

//func.func @simple_unpack_dynamic_tile_transpose(%input: tensor<1x1x2x?xf32>, %output: tensor<5x1xf32>, %tile_dim_0: index) -> tensor<5x1xf32> {
// %0 = tensor.unpack %input inner_dims_pos = [1, 0] inner_tiles = [2, %tile_dim_0] into %output : tensor<1x1x2x?xf32> -> tensor<5x1xf32>
// return %0 : tensor<5x1xf32>
//}

/// Same as example above, but with 1 scalable tile size.

Expand Down
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