[mlir][bufferization] Use Type instead of Value in unknown conversion (llvm#144658)

Generally, bufferization should be able to create a memref from a tensor
without needing to know more than just a mlir::Type. Thus, change
BufferizationOptions::UnknownTypeConverterFn to accept just a type
(mlir::TensorType for now) instead of mlir::Value. Additionally, apply
the same rationale to getMemRefType() helper function.

Both changes are prerequisites to enable custom types support in
one-shot bufferization.

Author: andrey-golubev

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

@@ -265,9 +265,9 @@ struct BufferizationOptions {
       std::function<BaseMemRefType(TensorType, Attribute memorySpace,
                                    func::FuncOp, const BufferizationOptions &)>;
   /// Tensor -> MemRef type converter.
-  /// Parameters: Value, memory space, bufferization options
+  /// Parameters: tensor type, memory space, bufferization options
   using UnknownTypeConverterFn = std::function<BaseMemRefType(
-      Value, Attribute memorySpace, const BufferizationOptions &)>;
+      TensorType, Attribute memorySpace, const BufferizationOptions &)>;
   // Produce a MemorySpace attribute from a tensor type
   using DefaultMemorySpaceFn =
       std::function<std::optional<Attribute>(TensorType t)>;
@@ -638,7 +638,7 @@ OpTy replaceOpWithNewBufferizedOp(RewriterBase &rewriter, Operation *op,
   return newOp;
 }
 
-/// Return a MemRefType to which the type of the given value can be bufferized.
+/// Return a MemRefType to which the TensorType can be bufferized.
 ///
 /// If possible, op bufferization implementations should not use this function
 /// and instead infer precise memref types for tensor results by themselves.
@@ -650,7 +650,8 @@ OpTy replaceOpWithNewBufferizedOp(RewriterBase &rewriter, Operation *op,
 /// Note: Canonicalization patterns could clean up layout maps and infer more
 /// precise layout maps after bufferization. However, many possible
 /// canonicalizations are currently not implemented.
-BaseMemRefType getMemRefType(Value value, const BufferizationOptions &options,
+BaseMemRefType getMemRefType(TensorType tensorType,
+                             const BufferizationOptions &options,
                              MemRefLayoutAttrInterface layout = {},
                              Attribute memorySpace = nullptr);
 

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

@@ -320,10 +320,9 @@ defaultFunctionArgTypeConverter(TensorType type, Attribute memorySpace,
 }
 /// Default unknown type converter: Use a fully dynamic layout map.
 BaseMemRefType
-defaultUnknownTypeConverter(Value value, Attribute memorySpace,
+defaultUnknownTypeConverter(TensorType tensorType, Attribute memorySpace,
                             const BufferizationOptions &options) {
-  return getMemRefTypeWithFullyDynamicLayout(
-      llvm::cast<TensorType>(value.getType()), memorySpace);
+  return getMemRefTypeWithFullyDynamicLayout(tensorType, memorySpace);
 }
 
 } // namespace
@@ -769,12 +768,10 @@ LogicalResult BufferizationOptions::createMemCpy(OpBuilder &b, Location loc,
 // Bufferization-specific IRMapping support with debugging.
 //===----------------------------------------------------------------------===//
 
-BaseMemRefType bufferization::getMemRefType(Value value,
+BaseMemRefType bufferization::getMemRefType(TensorType tensorType,
                                             const BufferizationOptions &options,
                                             MemRefLayoutAttrInterface layout,
                                             Attribute memorySpace) {
-  auto tensorType = llvm::cast<TensorType>(value.getType());
-
   // Case 1: Unranked memref type.
   if (auto unrankedTensorType =
           llvm::dyn_cast<UnrankedTensorType>(tensorType)) {
@@ -791,7 +788,7 @@ BaseMemRefType bufferization::getMemRefType(Value value,
                            memorySpace);
   }
 
-  return options.unknownTypeConverterFn(value, memorySpace, options);
+  return options.unknownTypeConverterFn(tensorType, memorySpace, options);
 }
 
 BaseMemRefType
@@ -926,10 +923,11 @@ FailureOr<BaseMemRefType> bufferization::detail::defaultGetBufferType(
     Value value, const BufferizationOptions &options,
     SmallVector<Value> &invocationStack) {
   assert(llvm::isa<TensorType>(value.getType()) && "expected tensor type");
+  auto tensorType = cast<TensorType>(value.getType());
 
   // No further analysis is possible for a block argument.
   if (llvm::isa<BlockArgument>(value))
-    return bufferization::getMemRefType(value, options);
+    return bufferization::getMemRefType(tensorType, options);
 
   // Value is an OpResult.
   Operation *op = getOwnerOfValue(value);
@@ -951,7 +949,7 @@ FailureOr<BaseMemRefType> bufferization::detail::defaultGetBufferType(
   if (!memSpace.has_value())
     return op->emitError("could not infer memory space");
 
-  return getMemRefType(value, options, /*layout=*/{}, *memSpace);
+  return getMemRefType(tensorType, options, /*layout=*/{}, *memSpace);
 }
 
 bool bufferization::detail::defaultIsRepetitiveRegion(

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

@@ -124,9 +124,9 @@ struct OneShotBufferizePass
                   "'unknown-type-conversion'");
         return signalPassFailure();
       }
-      opt.unknownTypeConverterFn = [=](Value value, Attribute memorySpace,
+      opt.unknownTypeConverterFn = [=](TensorType tensorType,
+                                       Attribute memorySpace,
                                        const BufferizationOptions &options) {
-        auto tensorType = cast<TensorType>(value.getType());
         if (unknownTypeConversionOption == LayoutMapOption::IdentityLayoutMap)
           return bufferization::getMemRefTypeWithStaticIdentityLayout(
               tensorType, memorySpace);

mlir/lib/Dialect/SparseTensor/Transforms/SparsificationAndBufferizationPass.cpp

@@ -218,10 +218,10 @@ mlir::getBufferizationOptionsForSparsification(bool analysisOnly) {
   OneShotBufferizationOptions options;
   options.bufferizeFunctionBoundaries = true;
   options.setFunctionBoundaryTypeConversion(LayoutMapOption::IdentityLayoutMap);
-  options.unknownTypeConverterFn = [](Value value, Attribute memorySpace,
+  options.unknownTypeConverterFn = [](TensorType tensorType,
+                                      Attribute memorySpace,
                                       const BufferizationOptions &options) {
-    return getMemRefTypeWithStaticIdentityLayout(
-        cast<TensorType>(value.getType()), memorySpace);
+    return getMemRefTypeWithStaticIdentityLayout(tensorType, memorySpace);
   };
   if (analysisOnly) {
     options.testAnalysisOnly = true;