[Mlir-commits] [mlir] [MLIR][OpenMP] Add `omp.private` op (PR #80955)

[Kareem Ergawy]

================
@@ -133,6 +133,97 @@ def DeclareTargetAttr : OpenMP_Attr<"DeclareTarget", "declaretarget"> {
   let assemblyFormat = "`<` struct(params) `>`";
 }
 
+//===----------------------------------------------------------------------===//
+// 2.19.4 Data-Sharing Attribute Clauses
+//===----------------------------------------------------------------------===//
+
+def DataSharingTypePrivate      : I32EnumAttrCase<"Private", 0, "private">;
+def DataSharingTypeFirstPrivate : I32EnumAttrCase<"FirstPrivate", 1, "firstprivate">;
+
+def DataSharingClauseType : I32EnumAttr<
+    "DataSharingClauseType",
+    "Type of a data-sharing clause",
+    [DataSharingTypePrivate, DataSharingTypeFirstPrivate]> {
+  let genSpecializedAttr = 0;
+  let cppNamespace = "::mlir::omp";
+}
+
+def DataSharingClauseTypeAttr : EnumAttr<
+    OpenMP_Dialect, DataSharingClauseType, "data_sharing_type"> {
+  let assemblyFormat = "`{` `type` `=` $value `}`";
+}
+
+def PrivateClauseOp : OpenMP_Op<"private", [IsolatedFromAbove]> {
+  let summary = "Provides declaration of [first]private logic.";
+  let description = [{
+    This operation provides a declaration of how to implement the
+    [first]privatization of a variable. The dialect users should provide
+    information about how to create an instance of the type in the alloc region
+    and how to initialize the copy from the original item in the copy region.
+
+    Examples:
+    ---------
+    * `private(x)` would be emitted as:
+    ```mlir
+    omp.private {type = private} @x.privatizer : !fir.ref<i32> alloc {
+    ^bb0(%arg0: !fir.ref<i32>):
+    %0 = ... allocate proper memory for the private clone ...
+    omp.yield(%0 : !fir.ref<i32>)
+    }
+    ```
+
+    * `firstprivate(x)` would be emitted as:
+    ```mlir
+    omp.private {type = firstprivate} @y.privatizer : !fir.ref<i32> alloc {
----------------
ergawy wrote:

`omp.private` will be used for both `private` and `firstprivate` clauses. The difference will be in the `type` attribute, so for `firstprivate` it will be `omp.private {type = firstprivate} ...`.

The name of the symbol itself can be whatever we like, i.e. we don't have any restrictions on the symbol name; the example just happens to use `y.privatizer`.

Let me know if that did not answer you questions.

https://github.com/llvm/llvm-project/pull/80955