[mlir][vector] Update syntax and representation of insert/extract_strided_slice

This commit updates the representation of both `extract_strided_slice`
and `insert_strided_slice` to primitive arrays of int64_ts, rather than
ArrayAttrs of IntegerAttrs. This prevents a lot of boilerplate
conversions between IntegerAttr and int64_t.

Because previously the offsets, strides, and sizes were in the
attribute dictionary (with no special syntax), simply replacing the
attribute types with `DenseI64ArrayAttr` would be a syntax break.

So since a break is unavoidable this commit also tackles a long-standing
TODO:

```mlir
// TODO: Evolve to a range form syntax similar to:
%1 = vector.extract_strided_slice %0[0:2:1][2:4:1]
  : vector<4x8x16xf32> to vector<2x4x16xf32>
```

This is done by introducing a new `StridedSliceAttr` attribute that can
be used for both operations, with syntax based on the above example.

See the attribute documentation `VectorAttributes.td` for a full
overview.

Author: MacDue

mlir/include/mlir/Dialect/Vector/IR/VectorAttributes.td

@@ -16,6 +16,11 @@
 include "mlir/Dialect/Vector/IR/Vector.td"
 include "mlir/IR/EnumAttr.td"
 
+class Vector_Attr<string attrName, string attrMnemonic, list<Trait> traits = []>
+    : AttrDef<Vector_Dialect, attrName, traits> {
+  let mnemonic = attrMnemonic;
+}
+
 // The "kind" of combining function for contractions and reductions.
 def COMBINING_KIND_ADD : I32BitEnumAttrCaseBit<"ADD", 0, "add">;
 def COMBINING_KIND_MUL : I32BitEnumAttrCaseBit<"MUL", 1, "mul">;
@@ -82,4 +87,63 @@ def Vector_PrintPunctuation : EnumAttr<Vector_Dialect, PrintPunctuation, "punctu
   let assemblyFormat = "`<` $value `>`";
 }
 
+def Vector_StridedSliceAttr : Vector_Attr<"StridedSlice", "strided_slice">
+{
+  let summary = "strided vector slice";
+
+  let description = [{
+    An attribute that represents a strided slice of a vector.
+
+    *Syntax:*
+
+    ```
+    offset = integer-literal
+    stride = integer-literal
+    size = integer-literal
+    offset-list = offset (`,` offset)*
+
+    // Without sizes (used for insert_strided_slice)
+    strided-slice-without-sizes = offset-list? (`[` offset `:` stride `]`)+
+
+    // With sizes (used for extract_strided_slice)
+    strided-slice-with-sizes = (`[` offset `:` size `:` stride `]`)+
+    ```
+
+    *Examples:*
+
+    Without sizes:
+
+    `[0:1][4:2]`
+
+    - The first dimension starts at offset 0 and is strided by 1
+    - The second dimension starts at offset 4 and is strided by 2
+
+    `[0, 1, 2][3:1][4:8]`
+
+    - The first three dimensions are indexed without striding (offsets 0, 1, 2)
+    - The fourth dimension starts at offset 3 and is strided by 1
+    - The fifth dimension starts at offset 4 and is strided by 8
+
+    With sizes (used for extract_strided_slice)
+
+    `[0:2:4][2:4:3]`
+
+    - The first dimension starts at offset 0, has size 2, and is strided by 4
+    - The second dimension starts at offset 2, has size 4, and is strided by 3
+  }];
+
+  let parameters = (ins
+    ArrayRefParameter<"int64_t">:$offsets,
+    OptionalArrayRefParameter<"int64_t">:$sizes,
+    ArrayRefParameter<"int64_t">:$strides
+  );
+
+  let builders = [AttrBuilder<(ins "ArrayRef<int64_t>":$offsets, "ArrayRef<int64_t>":$strides), [{
+      return $_get($_ctxt, offsets, ArrayRef<int64_t>{}, strides);
+    }]>
+  ];
+
+  let hasCustomAssemblyFormat = 1;
+}
+
 #endif // MLIR_DIALECT_VECTOR_IR_VECTOR_ATTRIBUTES

mlir/include/mlir/Dialect/Vector/IR/VectorOps.td

@@ -1040,8 +1040,8 @@ def Vector_InsertStridedSliceOp :
     PredOpTrait<"operand #0 and result have same element type",
                  TCresVTEtIsSameAsOpBase<0, 0>>,
     AllTypesMatch<["dest", "res"]>]>,
-    Arguments<(ins AnyVector:$source, AnyVector:$dest, I64ArrayAttr:$offsets,
-               I64ArrayAttr:$strides)>,
+    Arguments<(ins AnyVector:$source, AnyVector:$dest,
+               Vector_StridedSliceAttr:$strided_slice)>,
     Results<(outs AnyVector:$res)> {
   let summary = "strided_slice operation";
   let description = [{
@@ -1059,14 +1059,13 @@ def Vector_InsertStridedSliceOp :
     Example:
 
     ```mlir
-    %2 = vector.insert_strided_slice %0, %1
-        {offsets = [0, 0, 2], strides = [1, 1]}:
-      vector<2x4xf32> into vector<16x4x8xf32>
+    %2 = vector.insert_strided_slice %0, %1[0][0:1][2:1]
+      : vector<2x4xf32> into vector<16x4x8xf32>
     ```
   }];
 
   let assemblyFormat = [{
-    $source `,` $dest attr-dict `:` type($source) `into` type($dest)
+    $source `,` $dest `` $strided_slice attr-dict `:` type($source) `into` type($dest)
   }];
 
   let builders = [
@@ -1081,10 +1080,13 @@ def Vector_InsertStridedSliceOp :
       return ::llvm::cast<VectorType>(getDest().getType());
     }
     bool hasNonUnitStrides() {
-      return llvm::any_of(getStrides(), [](Attribute attr) {
-        return ::llvm::cast<IntegerAttr>(attr).getInt() != 1;
+      return llvm::any_of(getStrides(), [](int64_t stride) {
+        return stride != 1;
       });
     }
+
+    ArrayRef<int64_t> getOffsets() { return getStridedSlice().getOffsets(); }
+    ArrayRef<int64_t> getStrides() { return getStridedSlice().getStrides(); }
   }];
 
   let hasFolder = 1;
@@ -1182,8 +1184,7 @@ def Vector_ExtractStridedSliceOp :
   Vector_Op<"extract_strided_slice", [Pure,
     PredOpTrait<"operand and result have same element type",
                  TCresVTEtIsSameAsOpBase<0, 0>>]>,
-    Arguments<(ins AnyVector:$vector, I64ArrayAttr:$offsets,
-               I64ArrayAttr:$sizes, I64ArrayAttr:$strides)>,
+    Arguments<(ins AnyVector:$vector, Vector_StridedSliceAttr:$strided_slice)>,
     Results<(outs AnyVector)> {
   let summary = "extract_strided_slice operation";
   let description = [{
@@ -1200,13 +1201,8 @@ def Vector_ExtractStridedSliceOp :
     Example:
 
     ```mlir
-    %1 = vector.extract_strided_slice %0
-        {offsets = [0, 2], sizes = [2, 4], strides = [1, 1]}:
-      vector<4x8x16xf32> to vector<2x4x16xf32>
-
-    // TODO: Evolve to a range form syntax similar to:
     %1 = vector.extract_strided_slice %0[0:2:1][2:4:1]
-      vector<4x8x16xf32> to vector<2x4x16xf32>
+      : vector<4x8x16xf32> to vector<2x4x16xf32>
     ```
   }];
   let builders = [
@@ -1217,17 +1213,20 @@ def Vector_ExtractStridedSliceOp :
     VectorType getSourceVectorType() {
       return ::llvm::cast<VectorType>(getVector().getType());
     }
-    void getOffsets(SmallVectorImpl<int64_t> &results);
     bool hasNonUnitStrides() {
-      return llvm::any_of(getStrides(), [](Attribute attr) {
-        return ::llvm::cast<IntegerAttr>(attr).getInt() != 1;
+      return llvm::any_of(getStrides(), [](int64_t stride) {
+        return stride != 1;
       });
     }
+
+    ArrayRef<int64_t> getOffsets() { return getStridedSlice().getOffsets(); }
+    ArrayRef<int64_t> getSizes() { return getStridedSlice().getSizes(); }
+    ArrayRef<int64_t> getStrides() { return getStridedSlice().getStrides(); }
   }];
   let hasCanonicalizer = 1;
   let hasFolder = 1;
   let hasVerifier = 1;
-  let assemblyFormat = "$vector attr-dict `:` type($vector) `to` type(results)";
+  let assemblyFormat = "$vector `` $strided_slice attr-dict `:` type($vector) `to` type(results)";
 }
 
 // TODO: Tighten semantics so that masks and inbounds can't be used

mlir/lib/Conversion/VectorToGPU/VectorToGPU.cpp

@@ -940,12 +940,6 @@ convertTransferWriteToStores(RewriterBase &rewriter, vector::TransferWriteOp op,
   return success();
 }
 
-static void populateFromInt64AttrArray(ArrayAttr arrayAttr,
-                                       SmallVectorImpl<int64_t> &results) {
-  for (auto attr : arrayAttr)
-    results.push_back(cast<IntegerAttr>(attr).getInt());
-}
-
 static LogicalResult
 convertExtractStridedSlice(RewriterBase &rewriter,
                            vector::ExtractStridedSliceOp op,
@@ -996,11 +990,8 @@ convertExtractStridedSlice(RewriterBase &rewriter,
   auto sourceVector = it->second;
 
   // offset and sizes at warp-level of onwership.
-  SmallVector<int64_t> offsets;
-  populateFromInt64AttrArray(op.getOffsets(), offsets);
+  ArrayRef<int64_t> offsets = op.getOffsets();
 
-  SmallVector<int64_t> sizes;
-  populateFromInt64AttrArray(op.getSizes(), sizes);
   ArrayRef<int64_t> warpVectorShape = op.getSourceVectorType().getShape();
 
   // Compute offset in vector registers. Note that the mma.sync vector registers

mlir/lib/Conversion/VectorToSPIRV/VectorToSPIRV.cpp

@@ -46,9 +46,6 @@ static uint64_t getFirstIntValue(ValueRange values) {
 static uint64_t getFirstIntValue(ArrayRef<Attribute> attr) {
   return cast<IntegerAttr>(attr[0]).getInt();
 }
-static uint64_t getFirstIntValue(ArrayAttr attr) {
-  return (*attr.getAsValueRange<IntegerAttr>().begin()).getZExtValue();
-}
 static uint64_t getFirstIntValue(ArrayRef<OpFoldResult> foldResults) {
   auto attr = foldResults[0].dyn_cast<Attribute>();
   if (attr)
@@ -187,9 +184,9 @@ struct VectorExtractStridedSliceOpConvert final
     if (!dstType)
       return failure();
 
-    uint64_t offset = getFirstIntValue(extractOp.getOffsets());
-    uint64_t size = getFirstIntValue(extractOp.getSizes());
-    uint64_t stride = getFirstIntValue(extractOp.getStrides());
+    int64_t offset = extractOp.getOffsets().front();
+    int64_t size = extractOp.getSizes().front();
+    int64_t stride = extractOp.getStrides().front();
     if (stride != 1)
       return failure();
 
@@ -323,10 +320,10 @@ struct VectorInsertStridedSliceOpConvert final
     Value srcVector = adaptor.getOperands().front();
     Value dstVector = adaptor.getOperands().back();
 
-    uint64_t stride = getFirstIntValue(insertOp.getStrides());
+    uint64_t stride = insertOp.getStrides().front();
     if (stride != 1)
       return failure();
-    uint64_t offset = getFirstIntValue(insertOp.getOffsets());
+    uint64_t offset = insertOp.getOffsets().front();
 
     if (isa<spirv::ScalarType>(srcVector.getType())) {
       assert(!isa<spirv::ScalarType>(dstVector.getType()));

mlir/lib/Dialect/Arith/Transforms/IntNarrowing.cpp

@@ -549,11 +549,8 @@ struct ExtensionOverExtractStridedSlice final
     if (failed(ext))
       return failure();
 
-    VectorType origTy = op.getType();
-    VectorType extractTy =
-        origTy.cloneWith(origTy.getShape(), ext->getInElementType());
     Value newExtract = rewriter.create<vector::ExtractStridedSliceOp>(
-        op.getLoc(), extractTy, ext->getIn(), op.getOffsets(), op.getSizes(),
+        op.getLoc(), ext->getIn(), op.getOffsets(), op.getSizes(),
         op.getStrides());
     ext->recreateAndReplace(rewriter, op, newExtract);
     return success();