[mlir][bufferization][NFC] Move EmptyTensorToAllocTensorPass

This change moves the pass from the Linalg dialect to the bufferization dialect.

Differential Revision: https://reviews.llvm.org/D135130

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

@@ -46,6 +46,9 @@ LogicalResult promoteBufferResultsToOutParams(ModuleOp module);
 /// function argument.
 std::unique_ptr<Pass> createDropEquivalentBufferResultsPass();
 
+/// Create a pass that rewrites tensor.empty to bufferization.alloc_tensor.
+std::unique_ptr<Pass> createEmptyTensorToAllocTensorPass();
+
 /// Drop all memref function results that are equivalent to a function argument.
 LogicalResult dropEquivalentBufferResults(ModuleOp module);
 

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

@@ -168,6 +168,17 @@ def DropEquivalentBufferResults : Pass<"drop-equivalent-buffer-results", "Module
   let dependentDialects = ["memref::MemRefDialect"];
 }
 
+def EmptyTensorToAllocTensor : Pass<"empty-tensor-to-alloc-tensor"> {
+  let summary = "Replace all empty ops by alloc_tensor ops.";
+  let description = [{
+    tensor.empty ops return a tensor of unspecified contents who's only purpose
+    is to carry the tensor shape. This pass converts such ops to
+    bufferization.alloc_tensor ops, which bufferize to buffer allocations.
+  }];
+  let constructor = "mlir::bufferization::createEmptyTensorToAllocTensorPass()";
+  let dependentDialects = ["tensor::TensorDialect"];
+}
+
 def OneShotBufferize : Pass<"one-shot-bufferize", "ModuleOp"> {
   let summary = "One-Shot Bufferize";
   let description = [{

mlir/include/mlir/Dialect/Linalg/Passes.h

@@ -61,9 +61,6 @@ createConvertLinalgToParallelLoopsPass();
 std::unique_ptr<OperationPass<func::FuncOp>>
 createConvertLinalgToAffineLoopsPass();
 
-/// Create a pass that rewrites tensor.empty to bufferization.alloc_tensor.
-std::unique_ptr<Pass> createEmptyTensorToAllocTensorPass();
-
 /// Create a pass to convert Linalg operations which work on tensors to use
 /// buffers instead.
 std::unique_ptr<OperationPass<func::FuncOp>> createLinalgBufferizePass();

mlir/include/mlir/Dialect/Linalg/Passes.td

@@ -24,16 +24,6 @@ def ConvertElementwiseToLinalg : Pass<"convert-elementwise-to-linalg", ""> {
   let dependentDialects = ["linalg::LinalgDialect", "memref::MemRefDialect"];
 }
 
-def EmptyTensorToAllocTensor : Pass<"empty-tensor-to-alloc-tensor"> {
-  let summary = "Replace all empty ops by alloc_tensor ops.";
-  let description = [{
-    tensor.empty ops return a tensor of unspecified contents who's only purpose
-    is to carry the tensor shape. This pass converts such ops to
-    bufferization.alloc_tensor ops, which bufferize to buffer allocations.
-  }];
-  let constructor = "mlir::createEmptyTensorToAllocTensorPass()";
-}
-
 def LinalgFoldUnitExtentDims : Pass<"linalg-fold-unit-extent-dims", ""> {
   let summary = "Remove unit-extent dimension in Linalg ops on tensors";
   let constructor = "mlir::createLinalgFoldUnitExtentDimsPass()";

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

@@ -7,6 +7,7 @@ add_mlir_dialect_library(MLIRBufferizationTransforms
   BufferUtils.cpp
   BufferViewFlowAnalysis.cpp
   DropEquivalentBufferResults.cpp
+  EmptyTensorToAllocTensor.cpp
   FuncBufferizableOpInterfaceImpl.cpp
   OneShotAnalysis.cpp
   OneShotModuleBufferize.cpp

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

@@ -1,4 +1,4 @@
-//===- InitTensorToAllocTensor.cpp - Lower init_tensor to alloc_tensor ----===//
+//===- InitTensorToAllocTensor.cpp - Lower tensor.empty to alloc_tensor ---===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
@@ -6,7 +6,7 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "mlir/Dialect/Linalg/Passes.h"
+#include "mlir/Dialect/Bufferization/Transforms/Passes.h"
 
 #include "mlir/Dialect/Bufferization/IR/Bufferization.h"
 #include "mlir/Dialect/Tensor/IR/Tensor.h"
@@ -14,8 +14,10 @@
 #include "mlir/Transforms/GreedyPatternRewriteDriver.h"
 
 namespace mlir {
+namespace bufferization {
 #define GEN_PASS_DEF_EMPTYTENSORTOALLOCTENSOR
-#include "mlir/Dialect/Linalg/Passes.h.inc"
+#include "mlir/Dialect/Bufferization/Transforms/Passes.h.inc"
+} // namespace bufferization
 } // namespace mlir
 
 using namespace mlir;
@@ -35,7 +37,8 @@ struct EmptyTensorLoweringPattern : public OpRewritePattern<tensor::EmptyOp> {
 };
 
 struct EmptyTensorToAllocTensor
-    : public impl::EmptyTensorToAllocTensorBase<EmptyTensorToAllocTensor> {
+    : public bufferization::impl::EmptyTensorToAllocTensorBase<
+          EmptyTensorToAllocTensor> {
   EmptyTensorToAllocTensor() = default;
 
   void runOnOperation() override;
@@ -55,6 +58,7 @@ void EmptyTensorToAllocTensor::runOnOperation() {
     signalPassFailure();
 }
 
-std::unique_ptr<Pass> mlir::createEmptyTensorToAllocTensorPass() {
+std::unique_ptr<Pass>
+mlir::bufferization::createEmptyTensorToAllocTensorPass() {
   return std::make_unique<EmptyTensorToAllocTensor>();
 }

mlir/lib/Dialect/Linalg/Transforms/CMakeLists.txt

@@ -15,7 +15,6 @@ add_mlir_dialect_library(MLIRLinalgTransforms
   Generalization.cpp
   Hoisting.cpp
   HoistPadding.cpp
-  InitTensorToAllocTensor.cpp
   InlineScalarOperands.cpp
   Interchange.cpp
   Loops.cpp