Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

[mlir][Tensor] Use output_shape for DimOp->ExpandShapeOp folding #118203

Closed
wants to merge 1 commit into from
Closed

[mlir][Tensor] Use output_shape for DimOp->ExpandShapeOp folding #118203

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
32 changes: 6 additions & 26 deletions mlir/lib/Dialect/Tensor/IR/TensorOps.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1971,32 +1971,12 @@ struct FoldDimOfExpandShape : public OpRewritePattern<DimOp> {
if (!dim.has_value())
return failure();

// Skip static dims. These are folded to constant ops.
RankedTensorType resultType = expandShapeOp.getResultType();
if (!resultType.isDynamicDim(*dim))
return failure();

// Find reassociation group that contains this result dimension.
int64_t srcDim = expandShapeOp.getCorrespondingSourceDim(*dim);

// `dim` is the only dynamic dimension in `group`. (Otherwise, the
// ExpandShapeOp would be ambiguous.)
int64_t product = 1;
ReassociationIndices grp = expandShapeOp.getReassociationIndices()[srcDim];
for (int64_t d : grp) {
if (d != dim) {
assert(!resultType.isDynamicDim(d) && "expected static dim");
product *= resultType.getDimSize(d);
}
}

// result dim size = src dim size / (product(other dims in reassoc group))
Value srcDimSz =
rewriter.create<DimOp>(dimOp.getLoc(), expandShapeOp.getSrc(), srcDim);
AffineExpr expr;
bindSymbols(dimOp.getContext(), expr);
rewriter.replaceOpWithNewOp<affine::AffineApplyOp>(
dimOp, expr.floorDiv(product), srcDimSz);
SmallVector<OpFoldResult> outputShape =
getMixedValues(expandShapeOp.getStaticOutputShape(),
expandShapeOp.getOutputShape(), rewriter);
OpFoldResult outputDim = outputShape[dim.value()];
rewriter.replaceOp(dimOp, getValueOrCreateConstantIndexOp(
rewriter, dimOp.getLoc(), outputDim));
Copy link
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Can we just roll this into the folder for DimOp? The folder already handles the static case and has similar handling for extract_slice. This would have the added benefit of improving createOrFold<DimOp> which is used quite frequently.

return success();
}
};
Expand Down
8 changes: 2 additions & 6 deletions mlir/test/Dialect/Tensor/canonicalize.mlir
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -2278,13 +2278,9 @@ func.func @empty_tensor_canonicalize(%i : index) {

// -----

// CHECK: #[[$map:.*]] = affine_map<()[s0] -> (s0 floordiv 40)>
// CHECK-LABEL: func @dim_of_expand_shape(
// CHECK-SAME: %[[t:.*]]: tensor<?x?xf32>
// CHECK: %[[c1:.*]] = arith.constant 1 : index
// CHECK: %[[dim:.*]] = tensor.dim %[[t]], %[[c1]] : tensor<?x?xf32>
// CHECK: %[[apply:.*]] = affine.apply #[[$map]]()[%[[dim]]]
// CHECK: return %[[apply]]
// CHECK-SAME: %{{.*}}: tensor<?x?xf32>, %{{.*}}: index, %[[ARG2:.+]]: index
// CHECK: return %[[ARG2]]
func.func @dim_of_expand_shape(%t: tensor<?x?xf32>, %sz0: index, %sz1: index) -> index {
%c2 = arith.constant 2 : index
%0 = tensor.expand_shape %t [[0], [1, 2, 3, 4, 5]] output_shape [%sz0, 1, %sz1, 5, 1, 8]
Expand Down