[mlir] Replace dynamic sizes in insert_slice of tensor.cast canonicalization (#91352)

In some cases this pattern may ignore static information due to dynamic
operands in the insert_slice sizes operands, e.g.:
```
%0 = tensor.cast %arg0 : tensor<1x?xf32> to tensor<?x?xf32>
%1 = tensor.insert_slice %0 into %arg1[...] [%s0, %s1] [...] 
    : tensor<?x?xf32> into tensor<?x?xf32>
```
Can be rewritten into:
```
%1 = tensor.insert_slice %arg0 into %arg1[...] [1, %s1] [...] 
    : tensor<1x?xf32> into tensor<?x?xf32>
```
This PR updates the matching in the pattern to allow rewrites like this.
This commit is contained in:
Max191 2024-05-08 12:05:53 -07:00 committed by GitHub
parent 2f956a35ed
commit 7e35a9a0e7
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4 changed files with 73 additions and 31 deletions

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@ -360,9 +360,15 @@ private:
/// which dimensions must be kept when e.g. compute MemRef strides under
/// rank-reducing operations. Return std::nullopt if reducedShape cannot be
/// obtained by dropping only `1` entries in `originalShape`.
/// If `matchDynamic` is true, then dynamic dims in `originalShape` and
/// `reducedShape` will be considered matching with non-dynamic dims, unless
/// the non-dynamic dim is from `originalShape` and equal to 1. For example,
/// in ([1, 3, ?], [?, 5]), the mask would be {1, 0, 0}, since 3 and 5 will
/// match with the corresponding dynamic dims.
std::optional<llvm::SmallDenseSet<unsigned>>
computeRankReductionMask(ArrayRef<int64_t> originalShape,
ArrayRef<int64_t> reducedShape);
ArrayRef<int64_t> reducedShape,
bool matchDynamic = false);
/// Enum that captures information related to verifier error conditions on
/// slice insert/extract type of ops.

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@ -2713,15 +2713,38 @@ struct InsertSliceOpCastFolder final : public OpRewritePattern<InsertOpTy> {
auto dstType = llvm::dyn_cast<RankedTensorType>(dst.getType());
if (!srcType || !dstType)
return failure();
// The tensor.cast source could have additional static information not seen
// in the insert slice op static sizes, so we ignore dynamic dims when
// computing the rank reduction mask.
SmallVector<int64_t> staticSizes(insertSliceOp.getStaticSizes());
auto rankReductionMask = computeRankReductionMask(
staticSizes, srcType.getShape(), /*matchDynamic=*/true);
if (!rankReductionMask.has_value())
return failure();
// Replace dimensions in the insert slice op with corresponding static dims
// from the cast source type. If the insert slice sizes have static dims
// that are not static in the tensor.cast source (i.e., when the cast op
// casts a dynamic dim to static), the dim should not be replaced, and the
// pattern will fail later in `verifyInsertSliceOp`.
SmallVector<OpFoldResult> mixedSizes(insertSliceOp.getMixedSizes());
int64_t rankReducedIdx = 0;
for (auto [idx, size] : enumerate(staticSizes)) {
if (!rankReductionMask.value().contains(idx) &&
!srcType.isDynamicDim(rankReducedIdx)) {
mixedSizes[idx] = getAsIndexOpFoldResult(
rewriter.getContext(), srcType.getDimSize(rankReducedIdx));
size = srcType.getDimSize(rankReducedIdx++);
}
}
if (verifyInsertSliceOp(srcType, dstType, insertSliceOp.getStaticOffsets(),
insertSliceOp.getStaticSizes(),
insertSliceOp.getStaticStrides()) !=
staticSizes, insertSliceOp.getStaticStrides()) !=
SliceVerificationResult::Success)
return failure();
Operation *replacement = rewriter.create<InsertOpTy>(
insertSliceOp.getLoc(), src, dst, insertSliceOp.getMixedOffsets(),
insertSliceOp.getMixedSizes(), insertSliceOp.getMixedStrides());
mixedSizes, insertSliceOp.getMixedStrides());
// In the parallel case there is no result and so nothing to cast.
bool isParallelInsert =

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@ -408,24 +408,24 @@ unsigned BaseMemRefType::getMemorySpaceAsInt() const {
// MemRefType
//===----------------------------------------------------------------------===//
/// Given an `originalShape` and a `reducedShape` assumed to be a subset of
/// `originalShape` with some `1` entries erased, return the set of indices
/// that specifies which of the entries of `originalShape` are dropped to obtain
/// `reducedShape`. The returned mask can be applied as a projection to
/// `originalShape` to obtain the `reducedShape`. This mask is useful to track
/// which dimensions must be kept when e.g. compute MemRef strides under
/// rank-reducing operations. Return std::nullopt if reducedShape cannot be
/// obtained by dropping only `1` entries in `originalShape`.
std::optional<llvm::SmallDenseSet<unsigned>>
mlir::computeRankReductionMask(ArrayRef<int64_t> originalShape,
ArrayRef<int64_t> reducedShape) {
ArrayRef<int64_t> reducedShape,
bool matchDynamic) {
size_t originalRank = originalShape.size(), reducedRank = reducedShape.size();
llvm::SmallDenseSet<unsigned> unusedDims;
unsigned reducedIdx = 0;
for (unsigned originalIdx = 0; originalIdx < originalRank; ++originalIdx) {
// Greedily insert `originalIdx` if match.
if (reducedIdx < reducedRank &&
originalShape[originalIdx] == reducedShape[reducedIdx]) {
int64_t origSize = originalShape[originalIdx];
// if `matchDynamic`, count dynamic dims as a match, unless `origSize` is 1.
if (matchDynamic && reducedIdx < reducedRank && origSize != 1 &&
(ShapedType::isDynamic(reducedShape[reducedIdx]) ||
ShapedType::isDynamic(origSize))) {
reducedIdx++;
continue;
}
if (reducedIdx < reducedRank && origSize == reducedShape[reducedIdx]) {
reducedIdx++;
continue;
}
@ -433,7 +433,7 @@ mlir::computeRankReductionMask(ArrayRef<int64_t> originalShape,
unusedDims.insert(originalIdx);
// If no match on `originalIdx`, the `originalShape` at this dimension
// must be 1, otherwise we bail.
if (originalShape[originalIdx] != 1)
if (origSize != 1)
return std::nullopt;
}
// The whole reducedShape must be scanned, otherwise we bail.

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@ -755,6 +755,34 @@ func.func @fold_dim_of_tensor.cast(%arg0 : tensor<4x?xf32>) -> (index, index) {
// -----
// CHECK-LABEL: func @insert_slice_cast
func.func @insert_slice_cast(%arg0 : tensor<1x?xf32>, %arg1 : tensor<?x?xf32>, %arg2 : index, %arg3 : index, %arg4 : index, %arg5 : index, %arg6 : index, %arg7 : index) -> tensor<?x?xf32> {
// CHECK-SAME: %[[ARG0:.*]]: tensor<1x?xf32>
%0 = tensor.cast %arg0 : tensor<1x?xf32> to tensor<?x?xf32>
// CHECK: %[[RES:.*]] = tensor.insert_slice %[[ARG0]]
// CHECK-SAME: [{{.*}}, {{.*}}] [1, {{.*}}] [{{.*}}, {{.*}}]
// CHECK-SAME: : tensor<1x?xf32> into tensor<?x?xf32>
%1 = tensor.insert_slice %0 into %arg1[%arg2, %arg3] [%arg4, %arg5] [%arg6, %arg7] : tensor<?x?xf32> into tensor<?x?xf32>
// CHECK: return %[[RES]] : tensor<?x?xf32>
return %1 : tensor<?x?xf32>
}
// -----
// CHECK-LABEL: func @insert_slice_cast_no_fold
func.func @insert_slice_cast_no_fold(%arg0 : tensor<1x?xf32>, %arg1 : tensor<?x?xf32>, %arg2 : index, %arg3 : index, %arg4 : index, %arg5 : index, %arg6 : index, %arg7 : index) -> tensor<?x?xf32> {
%0 = tensor.cast %arg0 : tensor<1x?xf32> to tensor<?x5xf32>
// CHECK: %[[CAST:.*]] = tensor.cast
// CHECK: %[[RES:.*]] = tensor.insert_slice %[[CAST]]
// CHECK-SAME: [{{.*}}, {{.*}}] [{{.*}}, 5] [{{.*}}, {{.*}}]
// CHECK-SAME: : tensor<?x5xf32> into tensor<?x?xf32>
%1 = tensor.insert_slice %0 into %arg1[%arg2, %arg3] [%arg4, 5] [%arg6, %arg7] : tensor<?x5xf32> into tensor<?x?xf32>
// CHECK: return %[[RES]] : tensor<?x?xf32>
return %1 : tensor<?x?xf32>
}
// -----
// CHECK-LABEL: func @insert_tensor_cast_on_insert_slice_src(
// CHECK-SAME: %[[arg0:.*]]: tensor<?x5x?xf32>, %[[arg1:.*]]: tensor<?x?x?xf32>
// CHECK: %[[cast:.*]] = tensor.cast %[[arg0]] : tensor<?x5x?xf32> to tensor<64x5x64xf32>
@ -1890,21 +1918,6 @@ func.func @splat_dynamic_no_fold(%m: index) -> tensor<4x?xf32> {
// -----
// There was an issue in cast + insert_slice folding generating invalid ir.
// https://github.com/llvm/llvm-project/issues/53099
// CHECK-LABEL: func @insert_slice_cast
func.func @insert_slice_cast(%arg0 : tensor<1x?xf32>, %arg1 : tensor<?x?xf32>, %arg2 : index, %arg3 : index, %arg4 : index, %arg5 : index, %arg6 : index, %arg7 : index) -> tensor<?x?xf32> {
// CHECK: %[[CAST:.*]] = tensor.cast %{{.*}} : tensor<1x?xf32> to tensor<?x?xf32>
%0 = tensor.cast %arg0 : tensor<1x?xf32> to tensor<?x?xf32>
// CHECK: %[[RES:.*]] = tensor.insert_slice %[[CAST]]
// CHECK-SAME: : tensor<?x?xf32> into tensor<?x?xf32>
%1 = tensor.insert_slice %0 into %arg1[%arg2, %arg3] [%arg4, %arg5] [%arg6, %arg7] : tensor<?x?xf32> into tensor<?x?xf32>
// CHECK: return %[[RES]] : tensor<?x?xf32>
return %1 : tensor<?x?xf32>
}
// -----
// CHECK-LABEL: func @cast_extract_slice
func.func @cast_extract_slice(%arg0 : tensor<128x512xf32>, %s : index, %o : index)
-> tensor<16x512xf32> {