[mlir] Add InlinerInterface to bufferization dialect

[mehdi_amini]

Can you add a test please?

[Hardcode84]

Most (all?) other dialects don't have tests for this, do we really need it here?

[Hardcode84]

test

[mehdi_amini]

Most (all?) other dialects don't have tests for this, do we really need it here?

I would expect all of them to have a test for it, otherwise it's an oversight really (mlir/test/Dialect/Tosa/inlining.mlir, mlir/test/Dialect/Linalg/inlining.mlir, and mlir/test/Transforms/inlining.mlir covers Arithmetic).

I suspect for the dialects that got created from the split of StandardDialect they didn't get dedicated tests during the various refactoring (they probably should have though).

[mehdi_amini]

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

47

Actually can you keep a one line doc before each method to indicate which case they cover.

[Hardcode84]

One of these methods actually can be removed as this dialect doesn't have ops with nested regions.

mlir/lib/Dialect/Bufferization/IR/BufferizationDialect.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/Bufferization/IR/Bufferization.h"
+#include "mlir/Transforms/InliningUtils.h"
 
 using namespace mlir;
 using namespace mlir::bufferization;
 
 #include "mlir/Dialect/Bufferization/IR/BufferizationOpsDialect.cpp.inc"
 
 //===----------------------------------------------------------------------===//
+// Bufferization Dialect Interfaces
+//===----------------------------------------------------------------------===//
+
+namespace {
+struct BufferizationInlinerInterface : public DialectInlinerInterface {
+  using DialectInlinerInterface::DialectInlinerInterface;
+
+  /// Operations in Bufferization dialect are always legal to inline.
+  bool isLegalToInline(Operation *, Region *, bool,
+                       BlockAndValueMapping &) const final {
+    return true;
+  }
+};
+} // end anonymous namespace
+
+//===----------------------------------------------------------------------===//
 // Bufferization Dialect
 //===----------------------------------------------------------------------===//
 
 void mlir::bufferization::BufferizationDialect::initialize() {
   addOperations<
 #define GET_OP_LIST
 #include "mlir/Dialect/Bufferization/IR/BufferizationOps.cpp.inc"
       >();
+  addInterfaces<BufferizationInlinerInterface>();
 }

mlir/test/Dialect/Bufferization/inlining.mlir

+// RUN: mlir-opt %s -inline | FileCheck %s
+
+// CHECK-LABEL: func @test_inline
+// CHECK-SAME: (%[[ARG:.*]]: memref<*xf32>)
+// CHECK-NOT: call
+// CHECK: %[[RES:.*]] = bufferization.clone %[[ARG]]
+// CHECK: return %[[RES]]
+func @test_inline(%buf : memref<*xf32>) -> memref<*xf32> {
+  %0 = call @inner_func(%buf) : (memref<*xf32>) -> memref<*xf32>
+  return %0 : memref<*xf32>
+}
+
+func @inner_func(%buf : memref<*xf32>) -> memref<*xf32> {
+  %clone = bufferization.clone %buf : memref<*xf32> to memref<*xf32>
+  return %clone : memref<*xf32>
+}