[CIR] Add PointerLikeType interface support for cir::PointerType (#139768)

This adds code to attach the OpenACC PointerLikeType interface to
cir::PointerType, along with a unit test for the interface.

Author: andykaylor

clang/include/clang/CIR/Dialect/OpenACC/CIROpenACCTypeInterfaces.h

@@ -0,0 +1,35 @@
+//===----------------------------------------------------------------------===//
+//
+// 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 contains external dialect interfaces for CIR.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef CLANG_CIR_DIALECT_OPENACC_CIROPENACCTYPEINTERFACES_H
+#define CLANG_CIR_DIALECT_OPENACC_CIROPENACCTYPEINTERFACES_H
+
+#include "mlir/Dialect/OpenACC/OpenACC.h"
+
+namespace cir::acc {
+
+template <typename T>
+struct OpenACCPointerLikeModel
+    : public mlir::acc::PointerLikeType::ExternalModel<
+          OpenACCPointerLikeModel<T>, T> {
+  mlir::Type getElementType(mlir::Type pointer) const {
+    return mlir::cast<T>(pointer).getPointee();
+  }
+  mlir::acc::VariableTypeCategory
+  getPointeeTypeCategory(mlir::Type pointer,
+                         mlir::TypedValue<mlir::acc::PointerLikeType> varPtr,
+                         mlir::Type varType) const;
+};
+
+} // namespace cir::acc
+
+#endif // CLANG_CIR_DIALECT_OPENACC_CIROPENACCTYPEINTERFACES_H

clang/include/clang/CIR/Dialect/OpenACC/RegisterOpenACCExtensions.h

@@ -0,0 +1,22 @@
+//===----------------------------------------------------------------------===//
+//
+// 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 CLANG_CIR_DIALECT_OPENACC_REGISTEROPENACCEXTENSIONS_H
+#define CLANG_CIR_DIALECT_OPENACC_REGISTEROPENACCEXTENSIONS_H
+
+namespace mlir {
+class DialectRegistry;
+} // namespace mlir
+
+namespace cir::acc {
+
+void registerOpenACCExtensions(mlir::DialectRegistry &registry);
+
+} // namespace cir::acc
+
+#endif // CLANG_CIR_DIALECT_OPENACC_REGISTEROPENACCEXTENSIONS_H

clang/lib/CIR/CodeGen/CIRGenerator.cpp

@@ -18,6 +18,7 @@
 #include "clang/AST/DeclGroup.h"
 #include "clang/CIR/CIRGenerator.h"
 #include "clang/CIR/Dialect/IR/CIRDialect.h"
+#include "clang/CIR/Dialect/OpenACC/RegisterOpenACCExtensions.h"
 
 using namespace cir;
 using namespace clang;
@@ -38,6 +39,12 @@ void CIRGenerator::Initialize(ASTContext &astContext) {
   mlirContext = std::make_unique<mlir::MLIRContext>();
   mlirContext->loadDialect<cir::CIRDialect>();
   mlirContext->getOrLoadDialect<mlir::acc::OpenACCDialect>();
+
+  // Register extensions to integrate CIR types with OpenACC.
+  mlir::DialectRegistry registry;
+  cir::acc::registerOpenACCExtensions(registry);
+  mlirContext->appendDialectRegistry(registry);
+
   cgm = std::make_unique<clang::CIRGen::CIRGenModule>(
       *mlirContext.get(), astContext, codeGenOpts, diags);
 }

clang/lib/CIR/CodeGen/CMakeLists.txt

@@ -35,6 +35,7 @@ add_clang_library(clangCIR
   clangBasic
   clangLex
   ${dialect_libs}
+  CIROpenACCSupport
   MLIRCIR
   MLIRCIRInterfaces
 )

clang/lib/CIR/Dialect/CMakeLists.txt

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

clang/lib/CIR/Dialect/OpenACC/CIROpenACCTypeInterfaces.cpp

@@ -0,0 +1,65 @@
+//===----------------------------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// Implementation of external dialect interfaces for CIR.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/CIR/Dialect/OpenACC/CIROpenACCTypeInterfaces.h"
+#include "clang/CIR/Dialect/IR/CIRDialect.h"
+#include "clang/CIR/Dialect/IR/CIRTypes.h"
+
+namespace cir::acc {
+
+mlir::Type getBaseType(mlir::Value varPtr) {
+  mlir::Operation *op = varPtr.getDefiningOp();
+  assert(op && "Expected a defining operation");
+
+  // This is the variable definition we're looking for.
+  if (auto allocaOp = mlir::dyn_cast<cir::AllocaOp>(*op))
+    return allocaOp.getAllocaType();
+
+  // Look through casts to the source pointer.
+  if (auto castOp = mlir::dyn_cast<cir::CastOp>(*op))
+    return getBaseType(castOp.getSrc());
+
+  // Follow the source of ptr strides.
+  if (auto ptrStrideOp = mlir::dyn_cast<cir::PtrStrideOp>(*op))
+    return getBaseType(ptrStrideOp.getBase());
+
+  if (auto getMemberOp = mlir::dyn_cast<cir::GetMemberOp>(*op))
+    return getBaseType(getMemberOp.getAddr());
+
+  return mlir::cast<cir::PointerType>(varPtr.getType()).getPointee();
+}
+
+template <>
+mlir::acc::VariableTypeCategory
+OpenACCPointerLikeModel<cir::PointerType>::getPointeeTypeCategory(
+    mlir::Type pointer, mlir::TypedValue<mlir::acc::PointerLikeType> varPtr,
+    mlir::Type varType) const {
+  mlir::Type eleTy = getBaseType(varPtr);
+
+  if (auto mappableTy = mlir::dyn_cast<mlir::acc::MappableType>(eleTy))
+    return mappableTy.getTypeCategory(varPtr);
+
+  if (isAnyIntegerOrFloatingPointType(eleTy) ||
+      mlir::isa<cir::BoolType>(eleTy) || mlir::isa<cir::PointerType>(eleTy))
+    return mlir::acc::VariableTypeCategory::scalar;
+  if (mlir::isa<cir::ArrayType>(eleTy))
+    return mlir::acc::VariableTypeCategory::array;
+  if (mlir::isa<cir::RecordType>(eleTy))
+    return mlir::acc::VariableTypeCategory::composite;
+  if (mlir::isa<cir::FuncType>(eleTy) || mlir::isa<cir::VectorType>(eleTy))
+    return mlir::acc::VariableTypeCategory::nonscalar;
+
+  // Without further checking, this type cannot be categorized.
+  return mlir::acc::VariableTypeCategory::uncategorized;
+}
+
+} // namespace cir::acc

clang/lib/CIR/Dialect/OpenACC/CMakeLists.txt

@@ -0,0 +1,12 @@
+add_clang_library(CIROpenACCSupport
+  CIROpenACCTypeInterfaces.cpp
+  RegisterOpenACCExtensions.cpp
+
+  DEPENDS
+  MLIRCIRTypeConstraintsIncGen
+
+  LINK_LIBS PUBLIC
+  MLIRIR
+  MLIRCIR
+  MLIROpenACCDialect
+  )

clang/lib/CIR/Dialect/OpenACC/RegisterOpenACCExtensions.cpp

@@ -0,0 +1,27 @@
+//===----------------------------------------------------------------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+//
+// Registration for OpenACC extensions as applied to CIR dialect.
+//
+//===----------------------------------------------------------------------===//
+
+#include "clang/CIR/Dialect/OpenACC/RegisterOpenACCExtensions.h"
+#include "clang/CIR/Dialect/IR/CIRDialect.h"
+#include "clang/CIR/Dialect/IR/CIRTypes.h"
+#include "clang/CIR/Dialect/OpenACC/CIROpenACCTypeInterfaces.h"
+
+namespace cir::acc {
+
+void registerOpenACCExtensions(mlir::DialectRegistry &registry) {
+  registry.addExtension(+[](mlir::MLIRContext *ctx, cir::CIRDialect *dialect) {
+    cir::PointerType::attachInterface<
+        OpenACCPointerLikeModel<cir::PointerType>>(*ctx);
+  });
+}
+
+} // namespace cir::acc

clang/unittests/CIR/CMakeLists.txt

@@ -0,0 +1,16 @@
+set(MLIR_INCLUDE_DIR ${LLVM_MAIN_SRC_DIR}/../mlir/include )
+set(MLIR_TABLEGEN_OUTPUT_DIR ${CMAKE_BINARY_DIR}/tools/mlir/include)
+include_directories(SYSTEM ${MLIR_INCLUDE_DIR})
+include_directories(${MLIR_TABLEGEN_OUTPUT_DIR})
+
+add_distinct_clang_unittest(CIRUnitTests
+  PointerLikeTest.cpp
+  LLVM_COMPONENTS
+  Core
+
+  LINK_LIBS
+  MLIRCIR
+  CIROpenACCSupport
+  MLIRIR
+  MLIROpenACCDialect
+  )