Remove subview

Author: lialan

mlir/lib/Dialect/MemRef/Transforms/FlattenMemRefs.cpp

@@ -182,66 +182,6 @@ struct MemRefRewritePattern : public OpRewritePattern<T> {
   }
 };
 
-struct FlattenSubview : public OpRewritePattern<memref::SubViewOp> {
-  using OpRewritePattern::OpRewritePattern;
-
-  LogicalResult matchAndRewrite(memref::SubViewOp op,
-                                PatternRewriter &rewriter) const override {
-    Value memref = op.getSource();
-    if (!needFlattening(memref))
-      return rewriter.notifyMatchFailure(op, "already flattened");
-
-    if (!checkLayout(memref))
-      return rewriter.notifyMatchFailure(op, "unsupported layout");
-
-    Location loc = op.getLoc();
-    SmallVector<OpFoldResult> subOffsets = op.getMixedOffsets();
-    SmallVector<OpFoldResult> subSizes = op.getMixedSizes();
-    SmallVector<OpFoldResult> subStrides = op.getMixedStrides();
-
-    // base, finalOffset, strides
-    memref::ExtractStridedMetadataOp stridedMetadata =
-        rewriter.create<memref::ExtractStridedMetadataOp>(loc, memref);
-
-    auto sourceType = cast<MemRefType>(memref.getType());
-    auto typeBit = sourceType.getElementType().getIntOrFloatBitWidth();
-    OpFoldResult linearizedIndices;
-    memref::LinearizedMemRefInfo linearizedInfo;
-    std::tie(linearizedInfo, linearizedIndices) =
-        memref::getLinearizedMemRefOffsetAndSize(
-            rewriter, loc, typeBit, typeBit,
-            stridedMetadata.getConstifiedMixedOffset(),
-            stridedMetadata.getConstifiedMixedSizes(),
-            stridedMetadata.getConstifiedMixedStrides(), op.getMixedOffsets());
-    auto finalOffset = linearizedInfo.linearizedOffset;
-    auto strides = stridedMetadata.getConstifiedMixedStrides();
-
-    auto srcType = cast<MemRefType>(memref.getType());
-    auto resultType = cast<MemRefType>(op.getType());
-    unsigned subRank = static_cast<unsigned>(resultType.getRank());
-
-    llvm::SmallBitVector droppedDims = op.getDroppedDims();
-
-    SmallVector<OpFoldResult> finalSizes;
-    finalSizes.reserve(subRank);
-
-    SmallVector<OpFoldResult> finalStrides;
-    finalStrides.reserve(subRank);
-
-    for (auto i : llvm::seq(0u, static_cast<unsigned>(srcType.getRank()))) {
-      if (droppedDims.test(i))
-        continue;
-
-      finalSizes.push_back(subSizes[i]);
-      finalStrides.push_back(strides[i]);
-    }
-
-    rewriter.replaceOpWithNewOp<memref::ReinterpretCastOp>(
-        op, resultType, memref, finalOffset, finalSizes, finalStrides);
-    return success();
-  }
-};
-
 struct FlattenMemrefsPass
     : public mlir::memref::impl::FlattenMemrefsPassBase<FlattenMemrefsPass> {
   using Base::Base;
@@ -271,6 +211,6 @@ void memref::populateFlattenMemrefsPatterns(RewritePatternSet &patterns) {
                   MemRefRewritePattern<vector::TransferReadOp>,
                   MemRefRewritePattern<vector::TransferWriteOp>,
                   MemRefRewritePattern<vector::MaskedLoadOp>,
-                  MemRefRewritePattern<vector::MaskedStoreOp>, FlattenSubview>(
+                  MemRefRewritePattern<vector::MaskedStoreOp>>(
       patterns.getContext());
 }

mlir/test/Dialect/MemRef/flatten_memref.mlir

@@ -46,16 +46,6 @@ func.func @load_scalar_from_memref_dynamic_dim(%input: memref<?x?xf32, strided<[
 
 // -----
 
-func.func @load_scalar_from_memref_subview(%input: memref<4x8xf32>, %row: index, %col: index) -> memref<1x1xf32, strided<[8, 1], offset: ?>> {
-  %subview = memref.subview %input[%col, %row] [1, 1] [1, 1] : memref<4x8xf32> to memref<1x1xf32, strided<[8, 1], offset: ?>>
-  return %subview : memref<1x1xf32, strided<[8, 1], offset: ?>>
-}
-// CHECK-LABEL: func @load_scalar_from_memref_subview
-// CHECK-SAME: (%[[ARG0:.*]]: memref<4x8xf32>, %[[ARG1:.*]]: index, %[[ARG2:.*]]: index)
-// CHECK-NEXT: %[[REINT:.*]] = memref.reinterpret_cast %[[ARG0]] to offset: [0], sizes: [1, 1], strides: [8, 1]
-
-// -----
-
 func.func @store_scalar_from_memref_static_dim(%input: memref<4x8xf32, strided<[8, 12], offset: 100>>, %row: index, %col: index, %value: f32) {
   memref.store %value, %input[%col, %row] : memref<4x8xf32, strided<[8, 12], offset: 100>>
   return