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Author: yinying-lisa-li

mlir/include/mlir/Dialect/SparseTensor/IR/SparseTensorAttrDefs.td

@@ -167,7 +167,7 @@ def SparseTensorEncodingAttr : SparseTensor_Attr<"SparseTensorEncoding",
     - **soa** : only applicable to singleton levels, fuses the singleton
       level in SoA (structure of arrays) scheme.
 
-    In addition to the map, the following two fields are optional:
+    In addition to the map, the following four fields are optional:
 
     - The required bitwidth for position storage (integral offsets
       into the sparse storage scheme).  A narrow width reduces the memory
@@ -183,11 +183,11 @@ def SparseTensorEncodingAttr : SparseTensor_Attr<"SparseTensorEncoding",
       coordinate over all levels).  The choices are `8`, `16`, `32`,
       `64`, or, the default, `0` to indicate a native bitwidth.
 
-    - The required explicit value for the sparse tensor. If explicitVal is set,
+    - The explicit value for the sparse tensor. If explicitVal is set,
       then all the non-zero values in the tensor have the same explicit value.
       The default value Attribute() indicates that it is not set.
 
-    - The required implicit value for the sparse tensor. If implicitVal is set,
+    - The implicit value for the sparse tensor. If implicitVal is set,
       then the "zero" value in the tensor is equal to the implicit value.
       For now, we only support `0` as the implicit value but it could be
       extended in the future. The default value Attribute() indicates that

mlir/include/mlir/Dialect/SparseTensor/IR/SparseTensorType.h

@@ -343,10 +343,10 @@ class SparseTensorType {
   /// Returns the position-overhead bitwidth, defaulting to zero.
   unsigned getPosWidth() const { return enc ? enc.getPosWidth() : 0; }
 
-  /// Returns the explicit value, defaulting to empty Attribute.
+  /// Returns the explicit value, defaulting to null Attribute for unset.
   Attribute getExplicitVal() const { return enc.getExplicitVal(); }
 
-  /// Returns the implicit value, defaulting to empty Attribute.
+  /// Returns the implicit value, defaulting to null Attribute for 0.
   Attribute getImplicitVal() const { return enc.getImplicitVal(); }
 
   /// Returns the coordinate-overhead MLIR type, defaulting to `IndexType`.