[Mlir-commits] [mlir] [mlir][core|ptr] Add `PtrLikeTypeInterface` and casting ops to the `ptr` dialect (PR #137469)

[Oleksandr Alex Zinenko]

================
@@ -110,6 +110,55 @@ def MemRefElementTypeInterface : TypeInterface<"MemRefElementTypeInterface"> {
   }];
 }
 
+//===----------------------------------------------------------------------===//
+// PtrLikeTypeInterface
+//===----------------------------------------------------------------------===//
+
+def PtrLikeTypeInterface : TypeInterface<"PtrLikeTypeInterface"> {
+  let cppNamespace = "::mlir";
+  let description = [{
+    A ptr-like type represents an object storing a memory address. This object
+    is constituted by:
+    - A memory address called the base pointer. The base pointer is an 
+      indivisible object.
+    - Optional metadata about the pointer. For example, the size of the  memory
+      region associated with the pointer.
+
+    Furthermore, all ptr-like types have two properties:
+    - The memory space associated with the address held by the pointer.
+    - An optional element type. If the element type is not specified, the
+      pointer is considered opaque.
+  }];
+  let methods = [
+    InterfaceMethod<[{
+      Returns the memory space of this ptr-like type.
+    }],
+    "::mlir::Attribute", "getMemorySpace">,
+    InterfaceMethod<[{
+      Returns the element type of this ptr-like type. Note: this method can
+      return `::mlir::Type()`, in which case the pointer is considered opaque.
+    }],
+    "::mlir::Type", "getElementType">,
+    InterfaceMethod<[{
+      Returns whether this ptr-like type has non-empty metadata.
+    }],
+    "bool", "hasPtrMetadata">,
----------------
ftynse wrote:

Nit for bikeshedding, not blocking for PR: are we afraid of empty metadata because that would be equivalent to having a value of `void` type?

https://github.com/llvm/llvm-project/pull/137469