[mlir][memref] Fold extract_strided_metadata(cast(x)) into extract_strided_metadata(x) (#164585)

2026-01-26 12:26:52 +08:00 · 2025-10-23 08:54:38 +08:00
parent 9b5bc98743
commit 4eaeeab771
4 changed files with 133 additions and 214 deletions
--- a/mlir/lib/Dialect/MemRef/IR/MemRefOps.cpp
+++ b/mlir/lib/Dialect/MemRef/IR/MemRefOps.cpp
@@ -1437,6 +1437,13 @@ ExtractStridedMetadataOp::fold(FoldAdaptor adaptor,
  atLeastOneReplacement |= replaceConstantUsesOf(
      builder, getLoc(), getStrides(), getConstifiedMixedStrides());

+  // extract_strided_metadata(cast(x)) -> extract_strided_metadata(x).
+  if (auto prev = getSource().getDefiningOp<CastOp>())
+    if (isa<MemRefType>(prev.getSource().getType())) {
+      getSourceMutable().assign(prev.getSource());
+      atLeastOneReplacement = true;
+    }
+
  return success(atLeastOneReplacement);
 }

--- a/mlir/lib/Dialect/MemRef/Transforms/ExpandStridedMetadata.cpp
+++ b/mlir/lib/Dialect/MemRef/Transforms/ExpandStridedMetadata.cpp
@@ -1033,91 +1033,6 @@ class ExtractStridedMetadataOpReinterpretCastFolder
  }
 };

-/// Replace `base, offset, sizes, strides =
-///              extract_strided_metadata(
-///                 cast(src) to dstTy)`
-/// With
-/// ```
-/// base, ... = extract_strided_metadata(src)
-/// offset = !dstTy.srcOffset.isDynamic()
-///            ? dstTy.srcOffset
-///            : extract_strided_metadata(src).offset
-/// sizes = for each srcSize in dstTy.srcSizes:
-///           !srcSize.isDynamic()
-///             ? srcSize
-//              : extract_strided_metadata(src).sizes[i]
-/// strides = for each srcStride in dstTy.srcStrides:
-///             !srcStrides.isDynamic()
-///               ? srcStrides
-///               : extract_strided_metadata(src).strides[i]
-/// ```
-///
-/// In other words, consume the `cast` and apply its effects
-/// on the offset, sizes, and strides or compute them directly from `src`.
-class ExtractStridedMetadataOpCastFolder
-    : public OpRewritePattern<memref::ExtractStridedMetadataOp> {
-  using OpRewritePattern::OpRewritePattern;
-
-  LogicalResult
-  matchAndRewrite(memref::ExtractStridedMetadataOp extractStridedMetadataOp,
-                  PatternRewriter &rewriter) const override {
-    Value source = extractStridedMetadataOp.getSource();
-    auto castOp = source.getDefiningOp<memref::CastOp>();
-    if (!castOp)
-      return failure();
-
-    Location loc = extractStridedMetadataOp.getLoc();
-    // Check if the source is suitable for extract_strided_metadata.
-    SmallVector<Type> inferredReturnTypes;
-    if (failed(extractStridedMetadataOp.inferReturnTypes(
-            rewriter.getContext(), loc, {castOp.getSource()},
-            /*attributes=*/{}, /*properties=*/nullptr, /*regions=*/{},
-            inferredReturnTypes)))
-      return rewriter.notifyMatchFailure(castOp,
-                                         "cast source's type is incompatible");
-
-    auto memrefType = cast<MemRefType>(source.getType());
-    unsigned rank = memrefType.getRank();
-    SmallVector<OpFoldResult> results;
-    results.resize_for_overwrite(rank * 2 + 2);
-
-    auto newExtractStridedMetadata = memref::ExtractStridedMetadataOp::create(
-        rewriter, loc, castOp.getSource());
-
-    // Register the base_buffer.
-    results[0] = newExtractStridedMetadata.getBaseBuffer();
-
-    auto getConstantOrValue = [&rewriter](int64_t constant,
-                                          OpFoldResult ofr) -> OpFoldResult {
-      return ShapedType::isStatic(constant)
-                 ? OpFoldResult(rewriter.getIndexAttr(constant))
-                 : ofr;
-    };
-
-    auto [sourceStrides, sourceOffset] = memrefType.getStridesAndOffset();
-    assert(sourceStrides.size() == rank && "unexpected number of strides");
-
-    // Register the new offset.
-    results[1] =
-        getConstantOrValue(sourceOffset, newExtractStridedMetadata.getOffset());
-
-    const unsigned sizeStartIdx = 2;
-    const unsigned strideStartIdx = sizeStartIdx + rank;
-    ArrayRef<int64_t> sourceSizes = memrefType.getShape();
-
-    SmallVector<OpFoldResult> sizes = newExtractStridedMetadata.getSizes();
-    SmallVector<OpFoldResult> strides = newExtractStridedMetadata.getStrides();
-    for (unsigned i = 0; i < rank; ++i) {
-      results[sizeStartIdx + i] = getConstantOrValue(sourceSizes[i], sizes[i]);
-      results[strideStartIdx + i] =
-          getConstantOrValue(sourceStrides[i], strides[i]);
-    }
-    rewriter.replaceOp(extractStridedMetadataOp,
-                       getValueOrCreateConstantIndexOp(rewriter, loc, results));
-    return success();
-  }
-};
-
 /// Replace `base, offset, sizes, strides = extract_strided_metadata(
 ///      memory_space_cast(src) to dstTy)`
 /// with
@@ -1209,7 +1124,6 @@ void memref::populateExpandStridedMetadataPatterns(
               RewriteExtractAlignedPointerAsIndexOfViewLikeOp,
               ExtractStridedMetadataOpReinterpretCastFolder,
               ExtractStridedMetadataOpSubviewFolder,
-               ExtractStridedMetadataOpCastFolder,
               ExtractStridedMetadataOpMemorySpaceCastFolder,
               ExtractStridedMetadataOpAssumeAlignmentFolder,
               ExtractStridedMetadataOpExtractStridedMetadataFolder>(
@@ -1226,7 +1140,6 @@ void memref::populateResolveExtractStridedMetadataPatterns(
               ExtractStridedMetadataOpSubviewFolder,
               RewriteExtractAlignedPointerAsIndexOfViewLikeOp,
               ExtractStridedMetadataOpReinterpretCastFolder,
-               ExtractStridedMetadataOpCastFolder,
               ExtractStridedMetadataOpMemorySpaceCastFolder,
               ExtractStridedMetadataOpAssumeAlignmentFolder,
               ExtractStridedMetadataOpExtractStridedMetadataFolder>(
--- a/mlir/test/Dialect/MemRef/canonicalize.mlir
+++ b/mlir/test/Dialect/MemRef/canonicalize.mlir
@@ -901,6 +901,132 @@ func.func @scope_merge_without_terminator() {

 // -----

+// Check that we simplify extract_strided_metadata of cast
+// when the source of the cast is compatible with what
+// `extract_strided_metadata`s accept.
+//
+// When we apply the transformation the resulting offset, sizes and strides
+// should come straight from the inputs of the cast.
+// Additionally the folder on extract_strided_metadata should propagate the
+// static information.
+//
+// CHECK-LABEL: func @extract_strided_metadata_of_cast
+//  CHECK-SAME: %[[ARG:.*]]: memref<3x?xi32, strided<[4, ?], offset: ?>>)
+//
+//   CHECK-DAG: %[[C3:.*]] = arith.constant 3 : index
+//   CHECK-DAG: %[[C4:.*]] = arith.constant 4 : index
+//       CHECK: %[[BASE:.*]], %[[DYN_OFFSET:.*]], %[[DYN_SIZES:.*]]:2, %[[DYN_STRIDES:.*]]:2 = memref.extract_strided_metadata %[[ARG]]
+//
+//       CHECK: return %[[BASE]], %[[DYN_OFFSET]], %[[C3]], %[[DYN_SIZES]]#1, %[[C4]], %[[DYN_STRIDES]]#1
+func.func @extract_strided_metadata_of_cast(
+  %arg : memref<3x?xi32, strided<[4, ?], offset:?>>)
+  -> (memref<i32>, index,
+      index, index,
+      index, index) {
+
+  %cast =
+    memref.cast %arg :
+      memref<3x?xi32, strided<[4, ?], offset: ?>> to
+      memref<?x?xi32, strided<[?, ?], offset: ?>>
+
+  %base, %base_offset, %sizes:2, %strides:2 =
+    memref.extract_strided_metadata %cast:memref<?x?xi32, strided<[?, ?], offset: ?>>
+    -> memref<i32>, index,
+       index, index,
+       index, index
+
+  return %base, %base_offset,
+    %sizes#0, %sizes#1,
+    %strides#0, %strides#1 :
+      memref<i32>, index,
+      index, index,
+      index, index
+}
+
+// -----
+
+// Check that we simplify extract_strided_metadata of cast
+// when the source of the cast is compatible with what
+// `extract_strided_metadata`s accept.
+//
+// Same as extract_strided_metadata_of_cast but with constant sizes and strides
+// in the destination type.
+//
+// CHECK-LABEL: func @extract_strided_metadata_of_cast_w_csts
+//  CHECK-SAME: %[[ARG:.*]]: memref<?x?xi32, strided<[?, ?], offset: ?>>)
+//
+//   CHECK-DAG: %[[C4:.*]] = arith.constant 4 : index
+//   CHECK-DAG: %[[C18:.*]] = arith.constant 18 : index
+//   CHECK-DAG: %[[C25:.*]] = arith.constant 25 : index
+//       CHECK: %[[BASE:.*]], %[[DYN_OFFSET:.*]], %[[DYN_SIZES:.*]]:2, %[[DYN_STRIDES:.*]]:2 = memref.extract_strided_metadata %[[ARG]]
+//
+//       CHECK: return %[[BASE]], %[[C25]], %[[C4]], %[[DYN_SIZES]]#1, %[[DYN_STRIDES]]#0, %[[C18]]
+func.func @extract_strided_metadata_of_cast_w_csts(
+  %arg : memref<?x?xi32, strided<[?, ?], offset:?>>)
+  -> (memref<i32>, index,
+      index, index,
+      index, index) {
+
+  %cast =
+    memref.cast %arg :
+      memref<?x?xi32, strided<[?, ?], offset: ?>> to
+      memref<4x?xi32, strided<[?, 18], offset: 25>>
+
+  %base, %base_offset, %sizes:2, %strides:2 =
+    memref.extract_strided_metadata %cast:memref<4x?xi32, strided<[?, 18], offset: 25>>
+    -> memref<i32>, index,
+       index, index,
+       index, index
+
+  return %base, %base_offset,
+    %sizes#0, %sizes#1,
+    %strides#0, %strides#1 :
+      memref<i32>, index,
+      index, index,
+      index, index
+}
+
+// -----
+
+// Check that we don't simplify extract_strided_metadata of
+// cast when the source of the cast is unranked.
+// Unranked memrefs cannot feed into extract_strided_metadata operations.
+// Note: Technically we could still fold the sizes and strides.
+//
+// CHECK-LABEL: func @extract_strided_metadata_of_cast_unranked
+//  CHECK-SAME: %[[ARG:.*]]: memref<*xi32>)
+//
+//       CHECK: %[[CAST:.*]] = memref.cast %[[ARG]] :
+//       CHECK: %[[BASE:.*]], %[[OFFSET:.*]], %[[SIZES:.*]]:2, %[[STRIDES:.*]]:2 = memref.extract_strided_metadata %[[CAST]]
+//
+//       CHECK: return %[[BASE]], %[[OFFSET]], %[[SIZES]]#0, %[[SIZES]]#1, %[[STRIDES]]#0, %[[STRIDES]]#1
+func.func @extract_strided_metadata_of_cast_unranked(
+  %arg : memref<*xi32>)
+  -> (memref<i32>, index,
+      index, index,
+      index, index) {
+
+  %cast =
+    memref.cast %arg :
+      memref<*xi32> to
+      memref<?x?xi32, strided<[?, ?], offset: ?>>
+
+  %base, %base_offset, %sizes:2, %strides:2 =
+    memref.extract_strided_metadata %cast:memref<?x?xi32, strided<[?, ?], offset: ?>>
+    -> memref<i32>, index,
+       index, index,
+       index, index
+
+  return %base, %base_offset,
+    %sizes#0, %sizes#1,
+    %strides#0, %strides#1 :
+      memref<i32>, index,
+      index, index,
+      index, index
+}
+
+// -----
+
 // CHECK-LABEL: func @reinterpret_noop
 //  CHECK-SAME: (%[[ARG:.*]]: memref<2x3x4xf32>)
 //  CHECK-NEXT: return %[[ARG]]
--- a/mlir/test/Dialect/MemRef/expand-strided-metadata.mlir
+++ b/mlir/test/Dialect/MemRef/expand-strided-metadata.mlir
@@ -1376,133 +1376,6 @@ func.func @extract_strided_metadata_of_get_global_with_offset()
      memref<i32>, index, index, index, index, index
 }

-// -----
-
-// Check that we simplify extract_strided_metadata of cast
-// when the source of the cast is compatible with what
-// `extract_strided_metadata`s accept.
-//
-// When we apply the transformation the resulting offset, sizes and strides
-// should come straight from the inputs of the cast.
-// Additionally the folder on extract_strided_metadata should propagate the
-// static information.
-//
-// CHECK-LABEL: func @extract_strided_metadata_of_cast
-//  CHECK-SAME: %[[ARG:.*]]: memref<3x?xi32, strided<[4, ?], offset: ?>>)
-//
-//   CHECK-DAG: %[[C3:.*]] = arith.constant 3 : index
-//   CHECK-DAG: %[[C4:.*]] = arith.constant 4 : index
-//       CHECK: %[[BASE:.*]], %[[DYN_OFFSET:.*]], %[[DYN_SIZES:.*]]:2, %[[DYN_STRIDES:.*]]:2 = memref.extract_strided_metadata %[[ARG]]
-//
-//       CHECK: return %[[BASE]], %[[DYN_OFFSET]], %[[C3]], %[[DYN_SIZES]]#1, %[[C4]], %[[DYN_STRIDES]]#1
-func.func @extract_strided_metadata_of_cast(
-  %arg : memref<3x?xi32, strided<[4, ?], offset:?>>)
-  -> (memref<i32>, index,
-      index, index,
-      index, index) {
-
-  %cast =
-    memref.cast %arg :
-      memref<3x?xi32, strided<[4, ?], offset: ?>> to
-      memref<?x?xi32, strided<[?, ?], offset: ?>>
-
-  %base, %base_offset, %sizes:2, %strides:2 =
-    memref.extract_strided_metadata %cast:memref<?x?xi32, strided<[?, ?], offset: ?>>
-    -> memref<i32>, index,
-       index, index,
-       index, index
-
-  return %base, %base_offset,
-    %sizes#0, %sizes#1,
-    %strides#0, %strides#1 :
-      memref<i32>, index,
-      index, index,
-      index, index
-}
-
-// -----
-
-// Check that we simplify extract_strided_metadata of cast
-// when the source of the cast is compatible with what
-// `extract_strided_metadata`s accept.
-//
-// Same as extract_strided_metadata_of_cast but with constant sizes and strides
-// in the destination type.
-//
-// CHECK-LABEL: func @extract_strided_metadata_of_cast_w_csts
-//  CHECK-SAME: %[[ARG:.*]]: memref<?x?xi32, strided<[?, ?], offset: ?>>)
-//
-//   CHECK-DAG: %[[C4:.*]] = arith.constant 4 : index
-//   CHECK-DAG: %[[C18:.*]] = arith.constant 18 : index
-//   CHECK-DAG: %[[C25:.*]] = arith.constant 25 : index
-//       CHECK: %[[BASE:.*]], %[[DYN_OFFSET:.*]], %[[DYN_SIZES:.*]]:2, %[[DYN_STRIDES:.*]]:2 = memref.extract_strided_metadata %[[ARG]]
-//
-//       CHECK: return %[[BASE]], %[[C25]], %[[C4]], %[[DYN_SIZES]]#1, %[[DYN_STRIDES]]#0, %[[C18]]
-func.func @extract_strided_metadata_of_cast_w_csts(
-  %arg : memref<?x?xi32, strided<[?, ?], offset:?>>)
-  -> (memref<i32>, index,
-      index, index,
-      index, index) {
-
-  %cast =
-    memref.cast %arg :
-      memref<?x?xi32, strided<[?, ?], offset: ?>> to
-      memref<4x?xi32, strided<[?, 18], offset: 25>>
-
-  %base, %base_offset, %sizes:2, %strides:2 =
-    memref.extract_strided_metadata %cast:memref<4x?xi32, strided<[?, 18], offset: 25>>
-    -> memref<i32>, index,
-       index, index,
-       index, index
-
-  return %base, %base_offset,
-    %sizes#0, %sizes#1,
-    %strides#0, %strides#1 :
-      memref<i32>, index,
-      index, index,
-      index, index
-}
-
-// -----
-
-// Check that we don't simplify extract_strided_metadata of
-// cast when the source of the cast is unranked.
-// Unranked memrefs cannot feed into extract_strided_metadata operations.
-// Note: Technically we could still fold the sizes and strides.
-//
-// CHECK-LABEL: func @extract_strided_metadata_of_cast_unranked
-//  CHECK-SAME: %[[ARG:.*]]: memref<*xi32>)
-//
-//       CHECK: %[[CAST:.*]] = memref.cast %[[ARG]] :
-//       CHECK: %[[BASE:.*]], %[[OFFSET:.*]], %[[SIZES:.*]]:2, %[[STRIDES:.*]]:2 = memref.extract_strided_metadata %[[CAST]]
-//
-//       CHECK: return %[[BASE]], %[[OFFSET]], %[[SIZES]]#0, %[[SIZES]]#1, %[[STRIDES]]#0, %[[STRIDES]]#1
-func.func @extract_strided_metadata_of_cast_unranked(
-  %arg : memref<*xi32>)
-  -> (memref<i32>, index,
-      index, index,
-      index, index) {
-
-  %cast =
-    memref.cast %arg :
-      memref<*xi32> to
-      memref<?x?xi32, strided<[?, ?], offset: ?>>
-
-  %base, %base_offset, %sizes:2, %strides:2 =
-    memref.extract_strided_metadata %cast:memref<?x?xi32, strided<[?, ?], offset: ?>>
-    -> memref<i32>, index,
-       index, index,
-       index, index
-
-  return %base, %base_offset,
-    %sizes#0, %sizes#1,
-    %strides#0, %strides#1 :
-      memref<i32>, index,
-      index, index,
-      index, index
-}
-
-
 // -----

 memref.global "private" @dynamicShmem : memref<0xf16,3>