[mlir][vector] Linearization: push 'bit width' logic out of patterns

mlir/include/mlir/Dialect/Vector/Transforms/VectorRewritePatterns.h

@@ -392,18 +392,29 @@ void populateVectorNarrowTypeRewritePatterns(RewritePatternSet &patterns,
 void populateVectorTransposeNarrowTypeRewritePatterns(
     RewritePatternSet &patterns, PatternBenefit benefit = 1);
 
-/// Populates patterns for ND vectors (N >= 2) linearization and sets up the
-/// provided ConversionTarget with the appropriate legality configuration for
-/// the ops to get converted properly.
-void populateVectorLinearizeTypeConversionsAndLegality(
-    TypeConverter &typeConverter, RewritePatternSet &patterns,
-    ConversionTarget &target, unsigned targetBitWidth);
-
-/// Populates patterns for linearizing ND (N >= 2) vector operations to 1D
-/// vector shuffle operations.
-void populateVectorLinearizeShuffleLikeOpsPatterns(
-    const TypeConverter &typeConverter, RewritePatternSet &patterns,
-    ConversionTarget &target, unsigned targetBitWidth);
+/// Initialize `typeConverter` and `conversionTarget` for vector linearization.
+/// This registers (1) which operations are legal and hence should not be
+/// linearized, (2) what converted types are (rank-1 vectors) and how to
+/// materialze the conversion (with shape_cast)
+///
+/// Note: the set of legal operations can be extended by a user if for example
+/// certain rank>1 vectors are considered valid, but adding additional
+/// dynamically legal ops to `conversionTarget`.
+void populateForVectorLinearize(TypeConverter &typeConverter,
+                                ConversionTarget &conversionTarget);
+
+/// Populates `patterns` for ND vector (N >= 2) linearization. This currently
+/// contains patterns for converting ConstantLike, Vectorizable, and
+/// vector::BitCast ops.
+void populateVectorLinearizeBasePatterns(const TypeConverter &,
+                                         const ConversionTarget &,
+                                         RewritePatternSet &patterns);
+
+/// Populates `patterns` for linearizing ND (N >= 2) vector operations
+/// to 1D vector shuffle operations.
+void populateVectorLinearizeShuffleLikeOpsPatterns(const TypeConverter &,
+                                                   const ConversionTarget &,
+                                                   RewritePatternSet &patterns);
 
 } // namespace vector
 } // namespace mlir