[mlir][acc] Add utilities for acc dialect

flang/lib/Lower/OpenACC.cpp

@@ -34,6 +34,7 @@
 #include "flang/Semantics/scope.h"
 #include "flang/Semantics/tools.h"
 #include "mlir/Dialect/ControlFlow/IR/ControlFlowOps.h"
+#include "mlir/Dialect/OpenACC/OpenACCUtils.h"
 #include "mlir/IR/IRMapping.h"
 #include "mlir/IR/MLIRContext.h"
 #include "mlir/Support/LLVM.h"

mlir/include/mlir/Dialect/OpenACC/OpenACC.h

@@ -152,12 +152,6 @@ mlir::ValueRange getDataOperands(mlir::Operation *accOp);
 /// Used to get a mutable range iterating over the data operands.
 mlir::MutableOperandRange getMutableDataOperands(mlir::Operation *accOp);
 
-/// Used to obtain the enclosing compute construct operation that contains
-/// the provided `region`. Returns nullptr if no compute construct operation
-/// is found. The returns operation is one of types defined by
-///`ACC_COMPUTE_CONSTRUCT_OPS`.
-mlir::Operation *getEnclosingComputeOp(mlir::Region &region);
-
 /// Used to check whether the provided `type` implements the `PointerLikeType`
 /// interface.
 inline bool isPointerLikeType(mlir::Type type) {

mlir/include/mlir/Dialect/OpenACC/OpenACCUtils.h

@@ -0,0 +1,44 @@
+//===- OpenACCUtils.h - OpenACC Utilities -----------------------*- C++ -*-===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef MLIR_DIALECT_OPENACC_OPENACCUTILS_H_
+#define MLIR_DIALECT_OPENACC_OPENACCUTILS_H_
+
+#include "mlir/Dialect/OpenACC/OpenACC.h"
+
+namespace mlir {
+namespace acc {
+
+/// Used to obtain the enclosing compute construct operation that contains
+/// the provided `region`. Returns nullptr if no compute construct operation
+/// is found. The returned operation is one of types defined by
+/// `ACC_COMPUTE_CONSTRUCT_OPS`.
+mlir::Operation *getEnclosingComputeOp(mlir::Region &region);
+
+/// Returns true if this value is only used by `acc.private` operations in the
+/// `region`.
+bool isOnlyUsedByPrivateClauses(mlir::Value val, mlir::Region &region);
+
+/// Returns true if this value is only used by `acc.reduction` operations in
+/// the `region`.
+bool isOnlyUsedByReductionClauses(mlir::Value val, mlir::Region &region);
+
+/// Looks for an OpenACC default attribute on the current operation `op` or in
+/// a parent operation which encloses `op`. This is useful because OpenACC
+/// specification notes that a visible default clause is the nearest default
+/// clause appearing on the compute construct or a lexically containing data
+/// construct.
+std::optional<ClauseDefaultValue> getDefaultAttr(mlir::Operation *op);
+
+/// Get the type category of an OpenACC variable.
+mlir::acc::VariableTypeCategory getTypeCategory(mlir::Value var);
+
+} // namespace acc
+} // namespace mlir
+
+#endif // MLIR_DIALECT_OPENACC_OPENACCUTILS_H_

mlir/lib/Dialect/OpenACC/CMakeLists.txt

@@ -1,2 +1,3 @@
 add_subdirectory(IR)
+add_subdirectory(Utils)
 add_subdirectory(Transforms)

mlir/lib/Dialect/OpenACC/IR/OpenACC.cpp

@@ -4649,14 +4649,3 @@ mlir::acc::getMutableDataOperands(mlir::Operation *accOp) {
           .Default([&](mlir::Operation *) { return nullptr; })};
   return dataOperands;
 }
-
-mlir::Operation *mlir::acc::getEnclosingComputeOp(mlir::Region &region) {
-  mlir::Operation *parentOp = region.getParentOp();
-  while (parentOp) {
-    if (mlir::isa<ACC_COMPUTE_CONSTRUCT_OPS>(parentOp)) {
-      return parentOp;
-    }
-    parentOp = parentOp->getParentOp();
-  }
-  return nullptr;
-}

mlir/lib/Dialect/OpenACC/Utils/CMakeLists.txt

@@ -0,0 +1,20 @@
+add_mlir_dialect_library(MLIROpenACCUtils
+  OpenACCUtils.cpp
+
+  ADDITIONAL_HEADER_DIRS
+  ${MLIR_MAIN_INCLUDE_DIR}/mlir/Dialect/OpenACC
+
+  DEPENDS
+  MLIROpenACCPassIncGen
+  MLIROpenACCOpsIncGen
+  MLIROpenACCEnumsIncGen
+  MLIROpenACCAttributesIncGen
+  MLIROpenACCMPOpsInterfacesIncGen
+  MLIROpenACCOpsInterfacesIncGen
+  MLIROpenACCTypeInterfacesIncGen
+
+  LINK_LIBS PUBLIC
+  MLIROpenACCDialect
+  MLIRIR
+  MLIRSupport
+)

mlir/lib/Dialect/OpenACC/Utils/OpenACCUtils.cpp

@@ -0,0 +1,80 @@
+//===- OpenACCUtils.cpp ---------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#include "mlir/Dialect/OpenACC/OpenACCUtils.h"
+
+#include "mlir/Dialect/OpenACC/OpenACC.h"
+#include "llvm/ADT/TypeSwitch.h"
+
+mlir::Operation *mlir::acc::getEnclosingComputeOp(mlir::Region &region) {
+  mlir::Operation *parentOp = region.getParentOp();
+  while (parentOp) {
+    if (mlir::isa<ACC_COMPUTE_CONSTRUCT_OPS>(parentOp))
+      return parentOp;
+    parentOp = parentOp->getParentOp();
+  }
+  return nullptr;
+}
+
+template <typename OpTy>
+static bool isOnlyUsedByOpClauses(mlir::Value val, mlir::Region &region) {
+  auto checkIfUsedOnlyByOpInside = [&](mlir::Operation *user) {
+    // For any users which are not in the current acc region, we can ignore.
+    // Return true so that it can be used in a `all_of` check.
+    if (!region.isAncestor(user->getParentRegion()))
+      return true;
+    return mlir::isa<OpTy>(user);
+  };
+
+  return llvm::all_of(val.getUsers(), checkIfUsedOnlyByOpInside);
+}
+
+bool mlir::acc::isOnlyUsedByPrivateClauses(mlir::Value val,
+                                           mlir::Region &region) {
+  return isOnlyUsedByOpClauses<mlir::acc::PrivateOp>(val, region);
+}
+
+bool mlir::acc::isOnlyUsedByReductionClauses(mlir::Value val,
+                                             mlir::Region &region) {
+  return isOnlyUsedByOpClauses<mlir::acc::ReductionOp>(val, region);
+}
+
+std::optional<mlir::acc::ClauseDefaultValue>
+mlir::acc::getDefaultAttr(Operation *op) {
+  std::optional<mlir::acc::ClauseDefaultValue> defaultAttr;
+  Operation *currOp = op;
+
+  // Iterate outwards until a default clause is found (since OpenACC
+  // specification notes that a visible default clause is the nearest default
+  // clause appearing on the compute construct or a lexically containing data
+  // construct.
+  while (!defaultAttr.has_value() && currOp) {
+    defaultAttr =
+        llvm::TypeSwitch<mlir::Operation *,
+                         std::optional<mlir::acc::ClauseDefaultValue>>(currOp)
+            .Case<ACC_COMPUTE_CONSTRUCT_OPS, mlir::acc::DataOp>(
+                [&](auto op) { return op.getDefaultAttr(); })
+            .Default([&](Operation *) { return std::nullopt; });
+    currOp = currOp->getParentOp();
+  }
+
+  return defaultAttr;
+}
+
+mlir::acc::VariableTypeCategory mlir::acc::getTypeCategory(mlir::Value var) {
+  mlir::acc::VariableTypeCategory typeCategory =
+      mlir::acc::VariableTypeCategory::uncategorized;
+  if (auto mappableTy = dyn_cast<mlir::acc::MappableType>(var.getType()))
+    typeCategory = mappableTy.getTypeCategory(var);
+  else if (auto pointerLikeTy =
+               dyn_cast<mlir::acc::PointerLikeType>(var.getType()))
+    typeCategory = pointerLikeTy.getPointeeTypeCategory(
+        cast<TypedValue<mlir::acc::PointerLikeType>>(var),
+        pointerLikeTy.getElementType());
+  return typeCategory;
+}

mlir/unittests/Dialect/OpenACC/CMakeLists.txt

@@ -1,8 +1,13 @@
 add_mlir_unittest(MLIROpenACCTests
   OpenACCOpsTest.cpp
+  OpenACCUtilsTest.cpp
 )
 mlir_target_link_libraries(MLIROpenACCTests
   PRIVATE
   MLIRIR
+  MLIRFuncDialect
+  MLIRMemRefDialect
+  MLIRArithDialect
   MLIROpenACCDialect
+  MLIROpenACCUtils
 )