[Mlir-commits] [mlir] [mlir] Introduce `trailingNDimsContiguous` for MemRefs (PR #78247)

[Andrzej Warzyński]

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@@ -967,3 +967,32 @@ bool mlir::isLastMemrefDimUnitStride(MemRefType type) {
   auto successStrides = getStridesAndOffset(type, strides, offset);
   return succeeded(successStrides) && (strides.empty() || strides.back() == 1);
 }
+
+bool mlir::trailingNDimsContiguous(MemRefType type, int64_t n) {
+  if (!isLastMemrefDimUnitStride(type))
+    return false;
+
+  auto memrefShape = type.getShape().take_back(n);
+  int64_t offset;
+  SmallVector<int64_t> stridesFull;
+  if (!succeeded(getStridesAndOffset(type, stridesFull, offset)))
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banach-space wrote:

I've just added a check that leverages [isIdentity](https://github.com/llvm/llvm-project/blob/e3172e841899779caf461cee97826940dca806e7/mlir/include/mlir/IR/BuiltinAttributeInterfaces.td#L475-L482). 

> Is the memref layout being taken into account anywhere?

I thought that that's what `getStridesAndOffset` does (i.e. returns the layout as offsets and strides)? I am not 100% sure though, this is mostly just moving things around.

https://github.com/llvm/llvm-project/pull/78247