Revert "[mlir][SCF] Allow using a custom operation to generate loops with mlir::tileUsingSCF." (#159598)

Reverts llvm/llvm-project#159506

It was committed by accident. Reverting it for reviews.

Author: MaheshRavishankar

mlir/include/mlir/Dialect/SCF/Transforms/TileUsingInterface.h

@@ -33,14 +33,6 @@ using SCFTileSizeComputationFunction =
 
 /// Options to use to control tiling.
 struct SCFTilingOptions {
-  /// Specify which loop construct to use for tile and fuse.
-  enum class LoopType { ForOp, ForallOp, CustomOp };
-  LoopType loopType = LoopType::ForOp;
-  SCFTilingOptions &setLoopType(LoopType type) {
-    loopType = type;
-    return *this;
-  }
-
   /// Computation function that returns the tile sizes to use for each loop.
   /// Returning a tile size of zero implies no tiling for that loop. If the
   /// size of the returned vector is smaller than the number of loops, the inner
@@ -58,17 +50,6 @@ struct SCFTilingOptions {
   /// proper interaction with folding.
   SCFTilingOptions &setTileSizes(ArrayRef<OpFoldResult> tileSizes);
 
-  /// The interchange vector to reorder the tiled loops.
-  SmallVector<int64_t> interchangeVector = {};
-  SCFTilingOptions &setInterchange(ArrayRef<int64_t> interchange) {
-    interchangeVector = llvm::to_vector(interchange);
-    return *this;
-  }
-
-  //-------------------------------------------------------------------------//
-  // Options related to tiling using `scf.forall`.
-  //-------------------------------------------------------------------------//
-
   /// Computation function that returns the number of threads to use for
   /// each loop. Returning a num threads of zero implies no tiling for that
   /// loop. If the size of the returned vector is smaller than the number of
@@ -89,6 +70,21 @@ struct SCFTilingOptions {
   /// function that computes num threads at the point they are needed.
   SCFTilingOptions &setNumThreads(ArrayRef<OpFoldResult> numThreads);
 
+  /// The interchange vector to reorder the tiled loops.
+  SmallVector<int64_t> interchangeVector = {};
+  SCFTilingOptions &setInterchange(ArrayRef<int64_t> interchange) {
+    interchangeVector = llvm::to_vector(interchange);
+    return *this;
+  }
+
+  /// Specify which loop construct to use for tile and fuse.
+  enum class LoopType { ForOp, ForallOp };
+  LoopType loopType = LoopType::ForOp;
+  SCFTilingOptions &setLoopType(LoopType type) {
+    loopType = type;
+    return *this;
+  }
+
   /// Specify mapping of loops to devices. This is only respected when the loop
   /// constructs support such a mapping (like `scf.forall`). Will be ignored
   /// when using loop constructs that dont support such a mapping (like
@@ -121,98 +117,6 @@ struct SCFTilingOptions {
     reductionDims.insert(dims.begin(), dims.end());
     return *this;
   }
-
-  //-------------------------------------------------------------------------//
-  // Options related to tiling using custom loop.
-  //-------------------------------------------------------------------------//
-
-  // For generating the inter-tile loops using a custom loop, two callback
-  // functions are needed
-  // 1. That generates the "loop header", i.e. the loop that iterates over the
-  //    different tiles.
-  // 2. That generates the loop terminator
-  //
-  // For `scf.forall` case the call back to generate loop header would generate
-  //
-  // ```mlir
-  // scf.forall (...) = ... {
-  //   ..
-  // }
-  // ```
-  //
-  // and the call back to generate the loop terminator would generate the
-  // `scf.in_parallel` region
-  //
-  // ```mlir
-  // scf.forall (...) = ... {
-  //   scf.in_parallel {
-  //      tensor.parallel_insert_slice ...
-  //   }
-  // }
-  // ```
-  //
-
-  // Information that is to be returned by the callback to generate the loop
-  // header needed for the rest of the tiled codegeneration.
-  // - `loops`: The generated loops
-  // - `tileOffset`: The values that represent the offset of the iteration space
-  // tile
-  // - `tileSizes` : The values that represent the size of the iteration space
-  // tile.
-  // - `destinationTensors` : The tensors to use as destinations during tiling.
-  struct CustomLoopHeaderInfo {
-    SmallVector<LoopLikeOpInterface> loops;
-    SmallVector<OpFoldResult> tileOffset;
-    SmallVector<OpFoldResult> tileSizes;
-    SmallVector<Value> destinationTensors;
-  };
-
-  // Type of the callback function that generates the loop headers.
-  // - `loopRanges` : Values that represent the full size of the iteration space
-  //                  being tiled.
-  // - `giveTileSizes` : The tile sizes that are to be used to tile the
-  // iteration
-  //                     space.
-  // - `destinationTensors` : The tensors to use as destinations for the results
-  //                          of the tiled loop for loops that implement
-  //                          `DestinationStyleOpInterface`.
-  // Returns the `CustomLoopHeaderInfo` object (described above). it is expected
-  // that this function sets the insertion point of `rewriter` to the program
-  // point where the intra-tile loop computation is to be generated.
-  using GenerateLoopHeaderFn = std::function<FailureOr<CustomLoopHeaderInfo>(
-      RewriterBase &rewriter, Location loc, ArrayRef<Range> loopRanges,
-      ArrayRef<OpFoldResult> givenTileSizes, ValueRange destinationTensors)>;
-
-  // Type of the callback function that generates the loop terminator.
-  // - `tiledResults` : Tiles of the result computed for the iteration space
-  // tile
-  // - `resultOffsets` : For each of the `tiledResults`, the offset at which
-  //                     the result tile is to be "inserted" back into the
-  //                     destination tensor.
-  // - `resultSizes` : For each of the `tiledResults`, the size of the result
-  // tile
-  //                   that is to be "inserted" back into the destination
-  //                   tensor.
-  // Returns the `CustomLoopHeaderInfo` object (described above)
-  using GenerateLoopTerminatorFn = std::function<LogicalResult(
-      RewriterBase &rewriter, Location loc, ValueRange tiledResults,
-      ArrayRef<SmallVector<OpFoldResult>> resultOffsets,
-      ArrayRef<SmallVector<OpFoldResult>> resultSizes,
-      ValueRange destinationTensors)>;
-
-  // Callback function to generate the inter-tile loop header.
-  GenerateLoopHeaderFn generateLoopHeaderFn = nullptr;
-  // Callback function to generate the inter-tile loop terminator.
-  GenerateLoopTerminatorFn generateLoopTerminatorFn = nullptr;
-  // Helper function to set the callbacks for inter-tile loop header and
-  // terminator functions when using a custom operation for the loop.
-  SCFTilingOptions &
-  setCustomLoopGenerationFns(GenerateLoopHeaderFn headerFn,
-                             GenerateLoopTerminatorFn terminatorFn) {
-    generateLoopHeaderFn = std::move(headerFn);
-    generateLoopTerminatorFn = std::move(terminatorFn);
-    return *this;
-  }
 };
 
 /// Transformation information returned after tiling.