[mlir][bufferization] Add tensor-like and buffer-like interfaces

mlir/include/mlir/Dialect/Bufferization/IR/BufferizationTypeInterfaces.h

@@ -0,0 +1,18 @@
+//===- BufferizationTypeInterfaces.h - Type Interfaces ----------*- 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_BUFFERIZATION_IR_BUFFERIZATIONTYPEINTERFACES_H_
+#define MLIR_DIALECT_BUFFERIZATION_IR_BUFFERIZATIONTYPEINTERFACES_H_
+
+//===----------------------------------------------------------------------===//
+// Bufferization Type Interfaces
+//===----------------------------------------------------------------------===//
+
+#include "mlir/Dialect/Bufferization/IR/BufferizationTypeInterfaces.h.inc"
+
+#endif // MLIR_DIALECT_BUFFERIZATION_IR_BUFFERIZATIONTYPEINTERFACES_H_

mlir/include/mlir/Dialect/Bufferization/IR/BufferizationTypeInterfaces.td

@@ -0,0 +1,42 @@
+//===- BufferizationTypeInterfaces.td - Type Interfaces ----*- tablegen -*-===//
+//
+// 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 is the definition file for type interfaces used in Bufferization.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef BUFFERIZATION_TYPE_INTERFACES
+#define BUFFERIZATION_TYPE_INTERFACES
+
+include "mlir/IR/OpBase.td"
+
+def Bufferization_TensorLikeTypeInterface
+    : TypeInterface<"TensorLikeType"> {
+  let cppNamespace = "::mlir::bufferization";
+  let description = [{
+    Indicates that this type is a tensor type (similarly to a MLIR builtin
+    tensor) for bufferization purposes.
+
+    The interface currently has no methods as it is used by types to opt into
+    being supported by the bufferization procedures.
+  }];
+}
+
+def Bufferization_BufferLikeTypeInterface
+    : TypeInterface<"BufferLikeType"> {
+  let cppNamespace = "::mlir::bufferization";
+  let description = [{
+    Indicates that this type is a buffer type (similarly to a MLIR builtin
+    memref) for bufferization purposes.
+
+    The interface currently has no methods as it is used by types to opt into
+    being supported by the bufferization procedures.
+  }];
+}
+
+#endif // BUFFERIZATION_TYPE_INTERFACES

mlir/include/mlir/Dialect/Bufferization/IR/CMakeLists.txt

@@ -10,3 +10,9 @@ mlir_tablegen(BufferizationEnums.h.inc -gen-enum-decls)
 mlir_tablegen(BufferizationEnums.cpp.inc -gen-enum-defs)
 add_public_tablegen_target(MLIRBufferizationEnumsIncGen)
 add_dependencies(mlir-headers MLIRBufferizationEnumsIncGen)
+
+set(LLVM_TARGET_DEFINITIONS BufferizationTypeInterfaces.td)
+mlir_tablegen(BufferizationTypeInterfaces.h.inc -gen-type-interface-decls)
+mlir_tablegen(BufferizationTypeInterfaces.cpp.inc -gen-type-interface-defs)
+add_public_tablegen_target(MLIRBufferizationTypeInterfacesIncGen)
+add_dependencies(mlir-headers MLIRBufferizationTypeInterfacesIncGen)

mlir/include/mlir/Dialect/Bufferization/Transforms/Passes.td

@@ -471,6 +471,10 @@ def OneShotBufferizePass : Pass<"one-shot-bufferize", "ModuleOp"> {
     Statistic<"numTensorOutOfPlace", "num-tensor-out-of-place",
               "Number of out-of-place tensor OpOperands">,
   ];
+
+  let dependentDialects = [
+    "bufferization::BufferizationDialect", "memref::MemRefDialect"
+  ];
 }
 
 def PromoteBuffersToStackPass

mlir/lib/Dialect/Bufferization/IR/BufferizationDialect.cpp

@@ -9,8 +9,10 @@
 #include "mlir/Dialect/Affine/IR/AffineOps.h"
 #include "mlir/Dialect/Bufferization/IR/BufferizableOpInterface.h"
 #include "mlir/Dialect/Bufferization/IR/Bufferization.h"
+#include "mlir/Dialect/Bufferization/IR/BufferizationTypeInterfaces.h"
 #include "mlir/Dialect/MemRef/IR/MemRef.h"
 #include "mlir/Dialect/Tensor/IR/Tensor.h"
+#include "mlir/IR/BuiltinTypes.h"
 #include "mlir/Interfaces/FunctionInterfaces.h"
 #include "mlir/Transforms/InliningUtils.h"
 
@@ -51,6 +53,16 @@ struct BufferizationInlinerInterface : public DialectInlinerInterface {
     return true;
   }
 };
+
+template <typename Tensor>
+struct BuiltinTensorExternalModel
+    : TensorLikeType::ExternalModel<BuiltinTensorExternalModel<Tensor>,
+                                    Tensor> {};
+
+template <typename MemRef>
+struct BuiltinMemRefExternalModel
+    : BufferLikeType::ExternalModel<BuiltinMemRefExternalModel<MemRef>,
+                                    MemRef> {};
 } // namespace
 
 //===----------------------------------------------------------------------===//
@@ -63,6 +75,20 @@ void mlir::bufferization::BufferizationDialect::initialize() {
 #include "mlir/Dialect/Bufferization/IR/BufferizationOps.cpp.inc"
       >();
   addInterfaces<BufferizationInlinerInterface>();
+
+  // Note: Unlike with other external models, declaring bufferization's
+  // "promised interfaces" in builtins for TensorLike and BufferLike type
+  // interfaces is not possible (due to builtins being independent of
+  // bufferization). Thus, the compromise is to attach these interfaces directly
+  // during dialect initialization.
+  RankedTensorType::attachInterface<
+      BuiltinTensorExternalModel<RankedTensorType>>(*getContext());
+  UnrankedTensorType::attachInterface<
+      BuiltinTensorExternalModel<UnrankedTensorType>>(*getContext());
+  MemRefType::attachInterface<BuiltinMemRefExternalModel<MemRefType>>(
+      *getContext());
+  UnrankedMemRefType::attachInterface<
+      BuiltinMemRefExternalModel<UnrankedMemRefType>>(*getContext());
 }
 
 LogicalResult BufferizationDialect::verifyRegionArgAttribute(

mlir/lib/Dialect/Bufferization/Transforms/Bufferize.cpp

@@ -57,11 +57,6 @@ struct OneShotBufferizePass
           OneShotBufferizePass> {
   using Base::Base;
 
-  void getDependentDialects(DialectRegistry &registry) const override {
-    registry
-        .insert<bufferization::BufferizationDialect, memref::MemRefDialect>();
-  }
-
   void runOnOperation() override {
     OneShotBufferizationOptions opt;
     if (!options) {

mlir/test/Dialect/Bufferization/Transforms/tensorlike-bufferlike.mlir

@@ -0,0 +1,37 @@
+// RUN: mlir-opt %s -test-tensorlike-bufferlike -split-input-file | FileCheck %s
+
+// CHECK: func.func @builtin_unranked
+// CHECK-SAME: {found = {operand_0 = "is_tensor_like", result_0 = "is_buffer_like"}}
+func.func @builtin_unranked(%t: tensor<*xf32>) -> (memref<*xf32>)
+{
+  %0 = bufferization.to_memref %t : tensor<*xf32> to memref<*xf32>
+  return %0 : memref<*xf32>
+}
+
+// -----
+
+// CHECK: func.func @builtin_ranked
+// CHECK-SAME: {found = {operand_0 = "is_tensor_like", result_0 = "is_buffer_like"}}
+func.func @builtin_ranked(%t: tensor<42xf32>) -> (memref<42xf32>)
+{
+  %0 = bufferization.to_memref %t : tensor<42xf32> to memref<42xf32>
+  return %0 : memref<42xf32>
+}
+
+// -----
+
+// CHECK: func.func @custom_tensor
+// CHECK-SAME: {found = {operand_0 = "is_tensor_like"}}
+func.func @custom_tensor(%t: !test.test_tensor<[42], f32>) -> ()
+{
+  return
+}
+
+// -----
+
+// CHECK: func.func @custom_memref
+// CHECK-SAME: {found = {operand_0 = "is_buffer_like"}}
+func.func @custom_memref(%t: !test.test_memref<[42], f32>) -> ()
+{
+  return
+}

mlir/test/lib/Dialect/Bufferization/CMakeLists.txt

@@ -1,6 +1,7 @@
 # Exclude tests from libMLIR.so
 add_mlir_library(MLIRBufferizationTestPasses
   TestTensorCopyInsertion.cpp
+  TestTensorLikeAndBufferLike.cpp
 
   EXCLUDE_FROM_LIBMLIR
 )
@@ -9,4 +10,11 @@ mlir_target_link_libraries(MLIRBufferizationTestPasses PUBLIC
   MLIRBufferizationTransforms
   MLIRIR
   MLIRPass
+  MLIRTestDialect
 )
+
+target_include_directories(MLIRBufferizationTestPasses
+  PRIVATE
+  ${CMAKE_CURRENT_SOURCE_DIR}/../../Dialect/Test
+  ${CMAKE_CURRENT_BINARY_DIR}/../../Dialect/Test
+  )

mlir/test/lib/Dialect/Bufferization/TestTensorLikeAndBufferLike.cpp

@@ -0,0 +1,99 @@
+//===- TestTensorLikeAndBufferLike.cpp - Bufferization Test -----*- 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
+//
+//===----------------------------------------------------------------------===//
+
+#include "TestDialect.h"
+#include "mlir/Dialect/Bufferization/IR/Bufferization.h"
+#include "mlir/Dialect/Bufferization/IR/BufferizationTypeInterfaces.h"
+#include "mlir/Dialect/Func/IR/FuncOps.h"
+#include "mlir/IR/Attributes.h"
+#include "mlir/IR/BuiltinAttributes.h"
+#include "mlir/Pass/Pass.h"
+
+#include <string>
+
+using namespace mlir;
+
+namespace {
+std::string getImplementationStatus(Type type) {
+  if (isa<bufferization::TensorLikeType>(type)) {
+    return "is_tensor_like";
+  }
+  if (isa<bufferization::BufferLikeType>(type)) {
+    return "is_buffer_like";
+  }
+  return {};
+}
+
+DictionaryAttr findAllImplementeesOfTensorOrBufferLike(func::FuncOp funcOp) {
+  llvm::SmallVector<NamedAttribute> attributes;
+
+  const auto funcType = funcOp.getFunctionType();
+  for (auto [index, inputType] : llvm::enumerate(funcType.getInputs())) {
+    const auto status = getImplementationStatus(inputType);
+    if (status.empty()) {
+      continue;
+    }
+
+    attributes.push_back(
+        NamedAttribute(StringAttr::get(funcOp.getContext(),
+                                       "operand_" + std::to_string(index)),
+                       StringAttr::get(funcOp.getContext(), status)));
+  }
+
+  for (auto [index, resultType] : llvm::enumerate(funcType.getResults())) {
+    const auto status = getImplementationStatus(resultType);
+    if (status.empty()) {
+      continue;
+    }
+
+    attributes.push_back(NamedAttribute(
+        StringAttr::get(funcOp.getContext(), "result_" + std::to_string(index)),
+        StringAttr::get(funcOp.getContext(), status)));
+  }
+
+  return mlir::DictionaryAttr::get(funcOp.getContext(), attributes);
+}
+
+/// This pass tests whether specified types implement TensorLike and (or)
+/// BufferLike type interfaces defined in bufferization.
+///
+/// The pass analyses operation signature. When the aforementioned interface
+/// implementation found, an attribute is added to the operation, signifying the
+/// associated operand / result.
+struct TestTensorLikeAndBufferLikePass
+    : public PassWrapper<TestTensorLikeAndBufferLikePass,
+                         OperationPass<ModuleOp>> {
+  MLIR_DEFINE_EXPLICIT_INTERNAL_INLINE_TYPE_ID(TestTensorLikeAndBufferLikePass)
+
+  void getDependentDialects(DialectRegistry &registry) const override {
+    registry.insert<bufferization::BufferizationDialect, test::TestDialect>();
+  }
+  StringRef getArgument() const final { return "test-tensorlike-bufferlike"; }
+  StringRef getDescription() const final {
+    return "Module pass to test custom types that implement TensorLike / "
+           "BufferLike interfaces";
+  }
+
+  void runOnOperation() override {
+    auto op = getOperation();
+
+    op.walk([](func::FuncOp funcOp) {
+      const auto dict = findAllImplementeesOfTensorOrBufferLike(funcOp);
+      if (!dict.empty()) {
+        funcOp->setAttr("found", dict);
+      }
+    });
+  }
+};
+} // namespace
+
+namespace mlir::test {
+void registerTestTensorLikeAndBufferLikePass() {
+  PassRegistration<TestTensorLikeAndBufferLikePass>();
+}
+} // namespace mlir::test

mlir/test/lib/Dialect/Test/CMakeLists.txt

@@ -93,6 +93,7 @@ mlir_target_link_libraries(MLIRTestDialect PUBLIC
   MLIRTransformUtils
   MLIRTransforms
   MLIRValueBoundsOpInterface
+  MLIRBufferizationDialect
 )
 
 add_mlir_translation_library(MLIRTestFromLLVMIRTranslation

mlir/test/lib/Dialect/Test/TestTypeDefs.td

@@ -19,6 +19,7 @@ include "TestAttrDefs.td"
 include "TestInterfaces.td"
 include "mlir/IR/BuiltinTypes.td"
 include "mlir/Interfaces/DataLayoutInterfaces.td"
+include "mlir/Dialect/Bufferization/IR/BufferizationTypeInterfaces.td"
 
 // All of the types will extend this class.
 class Test_Type<string name, list<Trait> traits = []>
@@ -403,4 +404,49 @@ def TestTypeOpAsmTypeInterface : Test_Type<"TestTypeOpAsmTypeInterface",
   let mnemonic = "op_asm_type_interface";
 }
 
+def TestTensorType : Test_Type<"TestTensor",
+    [Bufferization_TensorLikeTypeInterface, ShapedTypeInterface]> {
+  let mnemonic = "test_tensor";
+  let parameters = (ins
+    ArrayRefParameter<"int64_t">:$shape,
+    "mlir::Type":$elementType
+  );
+  let assemblyFormat = "`<` `[` $shape `]` `,` $elementType `>`";
+
+  let extraClassDeclaration = [{
+    // ShapedTypeInterface:
+    bool hasRank() const {
+      return true;
+    }
+    test::TestTensorType cloneWith(std::optional<llvm::ArrayRef<int64_t>> shape,
+                                   mlir::Type elementType) const {
+      return test::TestTensorType::get(
+        getContext(), shape.value_or(getShape()), elementType);
+    }
+  }];
+}
+
+def TestMemrefType : Test_Type<"TestMemref",
+    [Bufferization_BufferLikeTypeInterface, ShapedTypeInterface]> {
+  let mnemonic = "test_memref";
+  let parameters = (ins
+    ArrayRefParameter<"int64_t">:$shape,
+    "mlir::Type":$elementType,
+    DefaultValuedParameter<"mlir::Attribute", "nullptr">:$memSpace
+  );
+  let assemblyFormat = "`<` `[` $shape `]` `,` $elementType (`,` $memSpace^)? `>`";
+
+  let extraClassDeclaration = [{
+    // ShapedTypeInterface:
+    bool hasRank() const {
+      return true;
+    }
+    test::TestMemrefType cloneWith(std::optional<llvm::ArrayRef<int64_t>> shape,
+                                   mlir::Type elementType) const {
+      return test::TestMemrefType::get(
+        getContext(), shape.value_or(getShape()), elementType, getMemSpace());
+    }
+  }];
+}
+
 #endif // TEST_TYPEDEFS

mlir/test/lib/Dialect/Test/TestTypes.h

@@ -18,6 +18,7 @@
 #include <tuple>
 
 #include "TestTraits.h"
+#include "mlir/Dialect/Bufferization/IR/BufferizationTypeInterfaces.h"
 #include "mlir/IR/Diagnostics.h"
 #include "mlir/IR/Dialect.h"
 #include "mlir/IR/DialectImplementation.h"

mlir/tools/mlir-opt/mlir-opt.cpp

@@ -149,6 +149,7 @@ void registerTestSPIRVCPURunnerPipeline();
 void registerTestSPIRVFuncSignatureConversion();
 void registerTestSPIRVVectorUnrolling();
 void registerTestTensorCopyInsertionPass();
+void registerTestTensorLikeAndBufferLikePass();
 void registerTestTensorTransforms();
 void registerTestTopologicalSortAnalysisPass();
 void registerTestTransformDialectEraseSchedulePass();
@@ -291,6 +292,7 @@ void registerTestPasses() {
   mlir::test::registerTestSPIRVFuncSignatureConversion();
   mlir::test::registerTestSPIRVVectorUnrolling();
   mlir::test::registerTestTensorCopyInsertionPass();
+  mlir::test::registerTestTensorLikeAndBufferLikePass();
   mlir::test::registerTestTensorTransforms();
   mlir::test::registerTestTopologicalSortAnalysisPass();
   mlir::test::registerTestTransformDialectEraseSchedulePass();