From 8f45c5862f82ca7e32c09ef84317daf66d278757 Mon Sep 17 00:00:00 2001
From: jacquesguan <Jianjian.Guan@streamcomputing.com>
Date: Thu, 30 Jun 2022 19:24:31 +0800
Subject: [PATCH] [mlir][Vector] Fold InsertStridedSliceOp of
 ExtractStridedSliceOp.

This patch supports to fold InsertStridedSliceOp(ExtractStridedSliceOp(dst), dst) to dst.

Differential Revision: https://reviews.llvm.org/D128903
---
 mlir/lib/Dialect/Vector/IR/VectorOps.cpp   | 34 +++++++++++++++++++++-
 mlir/test/Dialect/Vector/canonicalize.mlir | 14 +++++++++
 2 files changed, 47 insertions(+), 1 deletion(-)

diff --git a/mlir/lib/Dialect/Vector/IR/VectorOps.cpp b/mlir/lib/Dialect/Vector/IR/VectorOps.cpp
index 3edd23fef624..38f38f886705 100644
--- a/mlir/lib/Dialect/Vector/IR/VectorOps.cpp
+++ b/mlir/lib/Dialect/Vector/IR/VectorOps.cpp
@@ -2205,11 +2205,43 @@ public:
     return success();
   }
 };
+
+/// Pattern to rewrite an InsertStridedSliceOp(ExtractStridedSliceOp(dst), dst)
+/// to dst.
+class FoldInsertStridedSliceOfExtract final
+    : public OpRewritePattern<InsertStridedSliceOp> {
+public:
+  using OpRewritePattern<InsertStridedSliceOp>::OpRewritePattern;
+
+  LogicalResult matchAndRewrite(InsertStridedSliceOp insertStridedSliceOp,
+                                PatternRewriter &rewriter) const override {
+    auto extractStridedSliceOp =
+        insertStridedSliceOp.getSource()
+            .getDefiningOp<vector::ExtractStridedSliceOp>();
+
+    if (!extractStridedSliceOp)
+      return failure();
+
+    if (extractStridedSliceOp.getOperand() != insertStridedSliceOp.getDest())
+      return failure();
+
+    // Check if have the same strides and offsets.
+    if (extractStridedSliceOp.getStrides() !=
+            insertStridedSliceOp.getStrides() ||
+        extractStridedSliceOp.getOffsets() != insertStridedSliceOp.getOffsets())
+      return failure();
+
+    rewriter.replaceOp(insertStridedSliceOp, insertStridedSliceOp.getDest());
+    return success();
+  }
+};
+
 } // namespace
 
 void vector::InsertStridedSliceOp::getCanonicalizationPatterns(
     RewritePatternSet &results, MLIRContext *context) {
-  results.add<FoldInsertStridedSliceSplat>(context);
+  results.add<FoldInsertStridedSliceSplat, FoldInsertStridedSliceOfExtract>(
+      context);
 }
 
 OpFoldResult InsertStridedSliceOp::fold(ArrayRef<Attribute> operands) {
diff --git a/mlir/test/Dialect/Vector/canonicalize.mlir b/mlir/test/Dialect/Vector/canonicalize.mlir
index 7f50d9038045..515a2d1726b6 100644
--- a/mlir/test/Dialect/Vector/canonicalize.mlir
+++ b/mlir/test/Dialect/Vector/canonicalize.mlir
@@ -1641,3 +1641,17 @@ func.func @insert_strided_slice_splat(%x: f32) -> (vector<8x16xf32>) {
     : vector<4x4xf32> into vector<8x16xf32>
   return %0 : vector<8x16xf32>
 }
+
+
+// -----
+
+// CHECK-LABEL: @insert_extract_strided_slice
+//  CHECK-SAME: (%[[ARG:.*]]: vector<8x16xf32>)
+//  CHECK-NEXT:   return %[[ARG]] : vector<8x16xf32>
+func.func @insert_extract_strided_slice(%x: vector<8x16xf32>) -> (vector<8x16xf32>) {
+  %0 = vector.extract_strided_slice %x {offsets = [0, 8], sizes = [2, 4], strides = [1, 1]}
+        : vector<8x16xf32> to vector<2x4xf32>
+  %1 = vector.insert_strided_slice %0, %x {offsets = [0, 8], strides = [1, 1]}
+        : vector<2x4xf32> into vector<8x16xf32>
+  return %1 : vector<8x16xf32>
+}