[MLIR] Add decomposeMixedStridesOrOffsets and decomposeMixedSizes

Add the reverse functions to the ViewLikeInterface's functions
`getMixedStrides`, `getMixedSizes`, and `getMixedOffsets`. The new functions
are useful to build view-like operations from an array of mixed static/dynamic
values.

Differential Revision: https://reviews.llvm.org/D128376

Author: frgossen

mlir/include/mlir/Interfaces/ViewLikeInterface.h

@@ -49,6 +49,19 @@ SmallVector<OpFoldResult, 4> getMixedStrides(OffsetSizeAndStrideOpInterface op,
                                              ArrayAttr staticStrides,
                                              ValueRange strides);
 
+/// Decompose a vector of mixed static or dynamic strides/offsets into the
+/// corresponding pair of arrays. This is the inverse function of
+/// `getMixedStrides` and `getMixedOffsets`.
+std::pair<ArrayAttr, SmallVector<Value>> decomposeMixedStridesOrOffsets(
+    OpBuilder &b, const SmallVectorImpl<OpFoldResult> &mixedValues);
+
+/// Decompose a vector of mixed static or dynamic strides/offsets into the
+/// corresponding pair of arrays. This is the inverse function of
+/// `getMixedSizes`.
+std::pair<ArrayAttr, SmallVector<Value>>
+decomposeMixedSizes(OpBuilder &b,
+                    const SmallVectorImpl<OpFoldResult> &mixedValues);
+
 namespace detail {
 LogicalResult verifyOffsetSizeAndStrideOp(OffsetSizeAndStrideOpInterface op);
 

mlir/lib/Interfaces/ViewLikeInterface.cpp

@@ -242,3 +242,31 @@ mlir::getMixedStrides(OffsetSizeAndStrideOpInterface op,
   }
   return res;
 }
+
+static std::pair<ArrayAttr, SmallVector<Value>>
+decomposeMixedImpl(OpBuilder &b,
+                   const SmallVectorImpl<OpFoldResult> &mixedValues,
+                   const int64_t dynamicValuePlaceholder) {
+  SmallVector<int64_t> staticValues;
+  SmallVector<Value> dynamicValues;
+  for (const auto &it : mixedValues) {
+    if (it.is<Attribute>()) {
+      staticValues.push_back(it.get<Attribute>().cast<IntegerAttr>().getInt());
+    } else {
+      staticValues.push_back(ShapedType::kDynamicStrideOrOffset);
+      dynamicValues.push_back(it.get<Value>());
+    }
+  }
+  return {b.getI64ArrayAttr(staticValues), dynamicValues};
+}
+
+std::pair<ArrayAttr, SmallVector<Value>> mlir::decomposeMixedStridesOrOffsets(
+    OpBuilder &b, const SmallVectorImpl<OpFoldResult> &mixedValues) {
+  return decomposeMixedImpl(b, mixedValues, ShapedType::kDynamicStrideOrOffset);
+}
+
+std::pair<ArrayAttr, SmallVector<Value>>
+mlir::decomposeMixedSizes(OpBuilder &b,
+                          const SmallVectorImpl<OpFoldResult> &mixedValues) {
+  return decomposeMixedImpl(b, mixedValues, ShapedType::kDynamicSize);
+}