[mlir][sparse] minor cleanup of transform/utils (llvm#75396)

Consistent include macro naming
Modified and added comments

Author: aartbik

mlir/lib/Dialect/SparseTensor/Transforms/Utils/CodegenEnv.h

@@ -10,8 +10,8 @@
 //
 //===----------------------------------------------------------------------===//
 
-#ifndef MLIR_DIALECT_SPARSETENSOR_TRANSFORMS_CODEGENENV_H_
-#define MLIR_DIALECT_SPARSETENSOR_TRANSFORMS_CODEGENENV_H_
+#ifndef MLIR_DIALECT_SPARSETENSOR_TRANSFORMS_UTILS_CODEGENENV_H_
+#define MLIR_DIALECT_SPARSETENSOR_TRANSFORMS_UTILS_CODEGENENV_H_
 
 #include "CodegenUtils.h"
 #include "LoopEmitter.h"
@@ -206,4 +206,4 @@ class CodegenEnv {
 } // namespace sparse_tensor
 } // namespace mlir
 
-#endif // MLIR_DIALECT_SPARSETENSOR_TRANSFORMS_CODEGENENV_H_
+#endif // MLIR_DIALECT_SPARSETENSOR_TRANSFORMS_UTILS_CODEGENENV_H_

mlir/lib/Dialect/SparseTensor/Transforms/Utils/CodegenUtils.h

@@ -10,8 +10,8 @@
 //
 //===----------------------------------------------------------------------===//
 
-#ifndef MLIR_DIALECT_SPARSETENSOR_TRANSFORMS_CODEGENUTILS_H_
-#define MLIR_DIALECT_SPARSETENSOR_TRANSFORMS_CODEGENUTILS_H_
+#ifndef MLIR_DIALECT_SPARSETENSOR_TRANSFORMS_UTILS_CODEGENUTILS_H_
+#define MLIR_DIALECT_SPARSETENSOR_TRANSFORMS_UTILS_CODEGENUTILS_H_
 
 #include "mlir/Dialect/Arith/IR/Arith.h"
 #include "mlir/Dialect/Complex/IR/Complex.h"
@@ -434,4 +434,4 @@ inline bool isZeroRankedTensorOrScalar(Type type) {
 } // namespace sparse_tensor
 } // namespace mlir
 
-#endif // MLIR_DIALECT_SPARSETENSOR_TRANSFORMS_CODEGENUTILS_H_
+#endif // MLIR_DIALECT_SPARSETENSOR_TRANSFORMS_UTILS_CODEGENUTILS_H_

mlir/lib/Dialect/SparseTensor/Transforms/Utils/IterationGraphSorter.cpp

@@ -1,4 +1,4 @@
-//===- LoopScheduler.cpp -------------------------------------------------===//
+//===- IterationGraphSorter.cpp -------------------------------------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
@@ -20,11 +20,10 @@ using namespace mlir::sparse_tensor;
 
 namespace {
 
-/// A helper class that visits an affine expression and tries to find an
-/// AffineDimExpr to which the corresponding iterator from a GenericOp matches
-/// the desired iterator type.
-/// If there is no matched iterator type, returns the first DimExpr in the
-/// expression.
+/// A helper class that visits an affine expression and tries to find
+/// an AffineDimExpr to which the corresponding iterator from a GenericOp
+/// matches the desired iterator type. If there is no matched iterator
+/// type, the method returns the first DimExpr in the expression.
 class AffineDimFinder : public AffineExprVisitor<AffineDimFinder> {
 public:
   explicit AffineDimFinder(ArrayRef<utils::IteratorType> itTypes)
@@ -81,11 +80,9 @@ inline static bool includesDenseOutput(SortMask mask) {
   return includesAny(mask, SortMask::kIncludeDenseOutput);
 }
 
-/// A helper to compute a topological sort. O(n^2) time complexity
-/// as we use adj matrix for the graph.
-/// The sorted result will put the first Reduction iterator to the
-/// latest possible position.
 AffineMap IterationGraphSorter::topoSort() {
+  // The sorted result will put the first Reduction iterator to the
+  // latest possible position.
   std::vector<unsigned> redIt; // reduce iterator with 0 degree
   std::vector<unsigned> parIt; // parallel iterator with 0 degree
   const unsigned numLoops = getNumLoops();
@@ -170,6 +167,7 @@ AffineMap IterationGraphSorter::sort(SortMask mask, Value ignored) {
   // Reset the interation graph.
   for (auto &row : itGraph)
     std::fill(row.begin(), row.end(), false);
+
   // Reset cached in-degree.
   std::fill(inDegree.begin(), inDegree.end(), 0);
 
@@ -179,7 +177,6 @@ AffineMap IterationGraphSorter::sort(SortMask mask, Value ignored) {
     // Skip dense inputs when not requested.
     if ((!enc && !includesDenseInput(mask)) || in == ignored)
       continue;
-
     addConstraints(in, map);
   }
 

mlir/lib/Dialect/SparseTensor/Transforms/Utils/IterationGraphSorter.h

@@ -1,10 +1,17 @@
-//===- LoopScheduler.h -----------------------------------------*- C++ -*-===//
+//===- IterationGraphSorter.h -----------------------------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
+//
+// This header file defines the iteration graph sorter (top-sort scheduling).
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef MLIR_DIALECT_SPARSETENSOR_TRANSFORMS_UTILS_ITERATIONGRAPHSORTER_H_
+#define MLIR_DIALECT_SPARSETENSOR_TRANSFORMS_UTILS_ITERATIONGRAPHSORTER_H_
 
 #include "mlir/IR/AffineMap.h"
 
@@ -21,7 +28,7 @@ class GenericOp;
 
 namespace sparse_tensor {
 
-/// Iteration graph sorting.
+/// Iteration graph sorting mask,
 enum class SortMask : unsigned {
   // The individual mask bits.
   kIncludeDenseOutput = 0x1, // b001
@@ -34,40 +41,52 @@ enum class SortMask : unsigned {
 
 class IterationGraphSorter {
 public:
-  // Constructs a scheduler from linalg.generic
-  // Maybe reuses the class to schedule foreach as well (to address
-  // non-permutation, e.g, traverse CSR in BSR order).
+  /// Factory method that construct an iteration graph sorter
+  /// for the given linalg.generic operation.
   static IterationGraphSorter fromGenericOp(linalg::GenericOp genericOp);
 
-  // Returns a permutation that represents the scheduled loop order.
-  // Note that the returned AffineMap could be null if the kernel can not be
-  // schedule due to cycles in the iteration graph.
+  /// Returns a permutation that represents the scheduled loop order.
+  /// Note that the returned AffineMap could be null if the kernel
+  /// cannot be scheduled due to cyclic iteration graph.
   [[nodiscard]] AffineMap sort(SortMask mask, Value ignored = nullptr);
+
+  /// Returns the number of loops in the iteration graph.
   unsigned getNumLoops() const { return loop2OutLvl.getNumDims(); }
 
 private:
+  // Private constructor.
   IterationGraphSorter(SmallVector<Value> &&ins,
                        SmallVector<AffineMap> &&loop2InsLvl, Value out,
                        AffineMap loop2OutLvl,
                        SmallVector<utils::IteratorType> &&iterTypes);
 
+  // Adds all the constraints in the given loop to level map.
   void addConstraints(Value t, AffineMap loop2LvlMap);
+
+  /// A helper to compute a topological sort. The method has an
+  /// O(n^2) time complexity since we use an adjacency matrix
+  /// representation for the iteration graph.
   AffineMap topoSort();
 
   // Input tensors and associated loop to level maps.
   SmallVector<Value> ins;
   SmallVector<AffineMap> loop2InsLvl;
+
   // Output tensor and associated loop to level map.
   Value out;
   AffineMap loop2OutLvl;
-  // Loop type;
+
+  // Loop itation types;
   SmallVector<utils::IteratorType> iterTypes;
 
   // Adjacent matrix that represents the iteration graph.
   std::vector<std::vector<bool>> itGraph;
+
   // InDegree used for topo sort.
   std::vector<unsigned> inDegree;
 };
 
 } // namespace sparse_tensor
 } // namespace mlir
+
+#endif // MLIR_DIALECT_SPARSETENSOR_TRANSFORMS_UTILS_ITERATIONGRAPHSORTER_H_

mlir/lib/Dialect/SparseTensor/Transforms/Utils/LoopEmitter.h

@@ -6,8 +6,8 @@
 //
 //===----------------------------------------------------------------------===//
 
-#ifndef MLIR_DIALECT_SPARSETENSOR_TRANSFORMS_SPARSETENSORLOOPEMITTER_H_
-#define MLIR_DIALECT_SPARSETENSOR_TRANSFORMS_SPARSETENSORLOOPEMITTER_H_
+#ifndef MLIR_DIALECT_SPARSETENSOR_TRANSFORMS_UTILS_LOOPEMITTER_H_
+#define MLIR_DIALECT_SPARSETENSOR_TRANSFORMS_UTILS_LOOPEMITTER_H_
 
 #include <vector>
 
@@ -22,7 +22,7 @@ namespace sparse_tensor {
 // A compressed <tensor id, level> pair.
 using TensorLevel = unsigned;
 
-//===----------------------------------------------------------------------===//
+//
 // SparseTensorLoopEmiter class, manages sparse tensors and helps to
 // generate loop structure to (co)-iterate sparse tensors.
 //
@@ -48,8 +48,7 @@ using TensorLevel = unsigned;
 // loopEmiter.exitCurrentLoop(); // exit k
 // loopEmiter.exitCurrentLoop(); // exit j
 // loopEmiter.exitCurrentLoop(); // exit i
-//===----------------------------------------------------------------------===//
-
+//
 class LoopEmitter {
 public:
   /// Optional callback function to setup dense output tensors when
@@ -705,4 +704,4 @@ class LoopEmitter {
 } // namespace sparse_tensor
 } // namespace mlir
 
-#endif // MLIR_DIALECT_SPARSETENSOR_TRANSFORMS_SPARSETENSORLOOPEMITTER_H_
+#endif // MLIR_DIALECT_SPARSETENSOR_TRANSFORMS_UTILS_LOOPEMITTER_H_

mlir/lib/Dialect/SparseTensor/Transforms/Utils/SparseTensorDescriptor.h

@@ -10,8 +10,8 @@
 //
 //===----------------------------------------------------------------------===//
 
-#ifndef MLIR_DIALECT_SPARSETENSOR_TRANSFORMS_SPARSETENSORDESCRIPTOR_H_
-#define MLIR_DIALECT_SPARSETENSOR_TRANSFORMS_SPARSETENSORDESCRIPTOR_H_
+#ifndef MLIR_DIALECT_SPARSETENSOR_TRANSFORMS_UTILS_SPARSETENSORDESCRIPTOR_H_
+#define MLIR_DIALECT_SPARSETENSOR_TRANSFORMS_UTILS_SPARSETENSORDESCRIPTOR_H_
 
 #include "mlir/Dialect/SparseTensor/IR/SparseTensor.h"
 #include "mlir/Dialect/SparseTensor/IR/SparseTensorStorageLayout.h"
@@ -262,4 +262,4 @@ getMutDescriptorFromTensorTuple(Value tensor, SmallVectorImpl<Value> &fields) {
 } // namespace sparse_tensor
 } // namespace mlir
 
-#endif // MLIR_DIALECT_SPARSETENSOR_TRANSFORMS_SPARSETENSODESCRIPTOR_H_
+#endif // MLIR_DIALECT_SPARSETENSOR_TRANSFORMS_UTILS_SPARSETENSODESCRIPTOR_H_