[Mlir-commits] [mlir] [MLIR] Add pattern to fold insert_slice of extract_slice (PR #86328)

[Matthias Springer]

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@@ -142,11 +142,15 @@ mlir::tensor::getUnPackInverseSrcPerm(UnPackOp unpackOp,
 bool mlir::tensor::isCastLikeInsertSliceOp(InsertSliceOp op) {
   llvm::SmallBitVector droppedDims = op.getDroppedDims();
   int64_t srcDim = 0;
+  RankedTensorType resultType = op.getDestType();
   // Source dims and destination dims (apart from dropped dims) must have the
   // same size.
-  for (int64_t resultDim = 0; resultDim < op.getDestType().getRank();
-       ++resultDim) {
+  for (int64_t resultDim = 0; resultDim < resultType.getRank(); ++resultDim) {
     if (droppedDims.test(resultDim)) {
+      // InsertSlice may expand unit dimensions that result from inserting a
+      // size-1 slice into a non-size-1 result dimension.
+      if (resultType.getDimSize(resultDim) != 1)
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matthias-springer wrote:

Why is this needed? If a dimension is "dropped", it must be a unit dimension.


https://github.com/llvm/llvm-project/pull/86328