llvm-project/mlir/lib/Transforms/Bufferize.cpp

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4.7 KiB
C++

//===- Bufferize.cpp - Bufferization utilities ----------------------------===//
//
// 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/Transforms/Bufferize.h"
#include "PassDetail.h"
#include "mlir/Dialect/MemRef/IR/MemRef.h"
#include "mlir/IR/Operation.h"
#include "mlir/Transforms/Passes.h"
using namespace mlir;
//===----------------------------------------------------------------------===//
// BufferizeTypeConverter
//===----------------------------------------------------------------------===//
static Value materializeTensorLoad(OpBuilder &builder, TensorType type,
ValueRange inputs, Location loc) {
assert(inputs.size() == 1);
assert(inputs[0].getType().isa<BaseMemRefType>());
return builder.create<memref::TensorLoadOp>(loc, type, inputs[0]);
}
/// Registers conversions into BufferizeTypeConverter
BufferizeTypeConverter::BufferizeTypeConverter() {
// Keep all types unchanged.
addConversion([](Type type) { return type; });
// Convert RankedTensorType to MemRefType.
addConversion([](RankedTensorType type) -> Type {
return MemRefType::get(type.getShape(), type.getElementType());
});
// Convert UnrankedTensorType to UnrankedMemRefType.
addConversion([](UnrankedTensorType type) -> Type {
return UnrankedMemRefType::get(type.getElementType(), 0);
});
addArgumentMaterialization(materializeTensorLoad);
addSourceMaterialization(materializeTensorLoad);
addTargetMaterialization([](OpBuilder &builder, BaseMemRefType type,
ValueRange inputs, Location loc) -> Value {
assert(inputs.size() == 1);
assert(inputs[0].getType().isa<TensorType>());
return builder.create<memref::BufferCastOp>(loc, type, inputs[0]);
});
}
void mlir::populateBufferizeMaterializationLegality(ConversionTarget &target) {
target.addLegalOp<memref::TensorLoadOp, memref::BufferCastOp>();
}
namespace {
// In a finalizing bufferize conversion, we know that all tensors have been
// converted to memrefs, thus, this op becomes an identity.
class BufferizeTensorLoadOp : public OpConversionPattern<memref::TensorLoadOp> {
public:
using OpConversionPattern::OpConversionPattern;
LogicalResult
matchAndRewrite(memref::TensorLoadOp op, OpAdaptor adaptor,
ConversionPatternRewriter &rewriter) const override {
rewriter.replaceOp(op, adaptor.memref());
return success();
}
};
} // namespace
namespace {
// In a finalizing bufferize conversion, we know that all tensors have been
// converted to memrefs, thus, this op becomes an identity.
class BufferizeCastOp : public OpConversionPattern<memref::BufferCastOp> {
public:
using OpConversionPattern::OpConversionPattern;
LogicalResult
matchAndRewrite(memref::BufferCastOp op, OpAdaptor adaptor,
ConversionPatternRewriter &rewriter) const override {
rewriter.replaceOp(op, adaptor.tensor());
return success();
}
};
} // namespace
void mlir::populateEliminateBufferizeMaterializationsPatterns(
BufferizeTypeConverter &typeConverter, RewritePatternSet &patterns) {
patterns.add<BufferizeTensorLoadOp, BufferizeCastOp>(typeConverter,
patterns.getContext());
}
namespace {
struct FinalizingBufferizePass
: public FinalizingBufferizeBase<FinalizingBufferizePass> {
using FinalizingBufferizeBase<
FinalizingBufferizePass>::FinalizingBufferizeBase;
void runOnFunction() override {
auto func = getFunction();
auto *context = &getContext();
BufferizeTypeConverter typeConverter;
RewritePatternSet patterns(context);
ConversionTarget target(*context);
populateEliminateBufferizeMaterializationsPatterns(typeConverter, patterns);
// If all result types are legal, and all block arguments are legal (ensured
// by func conversion above), then all types in the program are legal.
//
// We also check that the operand types are legal to avoid creating invalid
// IR. For example, this prevents
// populateEliminateBufferizeMaterializationsPatterns from updating the
// types of the operands to a return op without updating the enclosing
// function.
target.markUnknownOpDynamicallyLegal(
[&](Operation *op) { return typeConverter.isLegal(op); });
if (failed(applyFullConversion(func, target, std::move(patterns))))
signalPassFailure();
}
};
} // namespace
std::unique_ptr<FunctionPass> mlir::createFinalizingBufferizePass() {
return std::make_unique<FinalizingBufferizePass>();
}