[mlir][scf][vector] Add scf.parallel vectorizer

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

@@ -0,0 +1,69 @@
+//===- SCFVectorize.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
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef MLIR_TRANSFORMS_SCFVECTORIZE_H_
+#define MLIR_TRANSFORMS_SCFVECTORIZE_H_
+
+#include <optional>
+
+namespace mlir {
+class DataLayout;
+struct LogicalResult;
+namespace scf {
+class ParallelOp;
+}
+namespace scf {
+
+/// Loop vectorization info
+struct SCFVectorizeInfo {
+  /// Loop dimension on which to vectorize.
+  unsigned dim = 0;
+
+  /// Biggest vector width, in elements.
+  unsigned factor = 0;
+
+  /// Number of ops, which will be vectorized.
+  unsigned count = 0;
+
+  /// Can use masked vector ops for our of bounds memory accesses.
+  bool masked = false;
+};
+
+/// Collect vectorization statistics on specified `scf.parallel` dimension.
+/// Return `SCFVectorizeInfo` or `std::nullopt` if loop cannot be vectorized on
+/// specified dimension.
+///
+/// `vectorBitwidth` - maximum vector size, in bits.
+std::optional<SCFVectorizeInfo>
+getLoopVectorizeInfo(mlir::scf::ParallelOp loop, unsigned dim,
+                     unsigned vectorBitwidth, const DataLayout *DL = nullptr);
+
+/// Vectorization params
+struct SCFVectorizeParams {
+  /// Loop dimension on which to vectorize.
+  unsigned dim = 0;
+
+  /// Desired vector length, in elements
+  unsigned factor = 0;
+
+  /// Use masked vector ops for memory access outside loop bounds.
+  bool masked = false;
+};
+
+/// Vectorize loop on specified dimension with specified factor.
+///
+/// If `masked` is `true` and loop bound is not divisible by `factor`, instead
+/// of generating second loop to process remainig iterations, extend loop count
+/// and generate masked vector ops to handle out-of bounds memory accesses.
+mlir::LogicalResult vectorizeLoop(mlir::scf::ParallelOp loop,
+                                  const SCFVectorizeParams &params,
+                                  const DataLayout *DL = nullptr);
+} // namespace scf
+} // namespace mlir
+
+#endif // MLIR_TRANSFORMS_SCFVECTORIZE_H_

mlir/lib/Dialect/SCF/Transforms/CMakeLists.txt

@@ -13,10 +13,11 @@ add_mlir_dialect_library(MLIRSCFTransforms
   ParallelLoopCollapsing.cpp
   ParallelLoopFusion.cpp
   ParallelLoopTiling.cpp
+  SCFVectorize.cpp
   StructuralTypeConversions.cpp
   TileUsingInterface.cpp
-  WrapInZeroTripCheck.cpp
   UpliftWhileToFor.cpp
+  WrapInZeroTripCheck.cpp
 
   ADDITIONAL_HEADER_DIRS
   ${MLIR_MAIN_INCLUDE_DIR}/mlir/Dialect/SCF