[Mlir-commits] [mlir] [mlir][Ptr] Add the `MemorySpaceAttrInterface` interface and dependencies. (PR #86870)

[Fabian Mora]

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@@ -0,0 +1,142 @@
+//===-- MemorySpaceInterfaces.td - Memory space interfaces ----------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines memory space attribute interfaces.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef PTR_MEMORYSPACEINTERFACES
+#define PTR_MEMORYSPACEINTERFACES
+
+include "mlir/IR/AttrTypeBase.td"
+include "mlir/IR/OpBase.td"
+
+//===----------------------------------------------------------------------===//
+// Memory space attribute interface.
+//===----------------------------------------------------------------------===//
+
+def MemorySpaceAttrInterface : AttrInterface<"MemorySpaceAttrInterface"> {
+  let description = [{
+    This interface defines a common API for interacting with the memory model of
+    a memory space and the operations in the pointer dialect, giving proper
+    semantical meaning to the ops.
+
+    Furthermore, this interface allows concepts such as read-only memory to be
+    adequately modeled and enforced.
+  }];
+  let cppNamespace = "::mlir::ptr";
+  let methods = [
+    InterfaceMethod<
+      /*desc=*/        [{
+        Returns the default memory space as an attribute.
+      }],
+      /*returnType=*/  "::mlir::ptr::MemorySpaceAttrInterface",
+      /*methodName=*/  "getDefaultMemorySpace"
+    >,
----------------
fabianmcg wrote:

We currently require a default space for the data layout. There are 2 options:
1. Create a convention and say that a given fixed attribute is the default space, let's say `#ptr.default_space`
2. Allow collections of memory spaces to specify what is the default space.

1 has the drawback that `#llvm.address_space<0>` wouldn't be the default, so it has the potential to create issues with existing code.

That's why I chose option 2.

https://github.com/llvm/llvm-project/pull/86870