[mlir][vector][transform] Add ApplyCastAwayVectorLeadingOneDimPatternsOp

[springerm]

Summary

Expose the respective patterns as a transform op.

[guraypp]

looks clean

mlir/include/mlir/Dialect/Vector/TransformOps/VectorTransformOps.td

 #define VECTOR_TRANSFORM_OPS
 
 include "mlir/Dialect/Transform/IR/TransformDialect.td"
 include "mlir/Dialect/Transform/IR/TransformInterfaces.td"
 include "mlir/Dialect/Vector/Transforms/VectorTransformsBase.td"
 include "mlir/Interfaces/SideEffectInterfaces.td"
 include "mlir/IR/OpBase.td"
 
+def ApplyCastAwayVectorLeadingOneDimPatternsOp : Op<Transform_Dialect,
+    "apply_patterns.vector.cast_away_vector_leading_one_dim",
+    [DeclareOpInterfaceMethods<PatternDescriptorOpInterface>]> {
+  let description = [{
+    Collect a set of leading one dimension removal patterns.
+
+    These patterns insert vector.shape_cast to remove leading one dimensions
+    to expose more canonical forms of read/write/insert/extract operations.
+    With them, there are more chances that we can cancel out extract-insert
+    pairs or forward write-read pairs.
+  }];
+
+  let assemblyFormat = "attr-dict";
+}
+
 def ApplyRankReducingSubviewPatternsOp : Op<Transform_Dialect,
     "apply_patterns.vector.apply_rank_reducing_subview_patterns",
     [DeclareOpInterfaceMethods<PatternDescriptorOpInterface>]> {
   let description = [{
     Apply opt-in vector transfer permutation patterns that include:
       - TransferReadDropUnitDimsPattern
       - TransferWriteDropUnitDimsPattern
 

mlir/lib/Dialect/Vector/TransformOps/VectorTransformOps.cpp

 using namespace mlir;
 using namespace mlir::vector;
 using namespace mlir::transform;
 
 //===----------------------------------------------------------------------===//
 // Apply...PatternsOp
 //===----------------------------------------------------------------------===//
 
+void transform::ApplyCastAwayVectorLeadingOneDimPatternsOp::populatePatterns(
+    RewritePatternSet &patterns) {
+  vector::populateCastAwayVectorLeadingOneDimPatterns(patterns);
+}
+
 void transform::ApplyRankReducingSubviewPatternsOp::populatePatterns(
     RewritePatternSet &patterns) {
   vector::populateVectorTransferDropUnitDimsPatterns(patterns);
 }
 
 void transform::ApplyTransferPermutationPatternsOp::populatePatterns(
     RewritePatternSet &patterns) {
   vector::populateVectorTransferPermutationMapLoweringPatterns(patterns);