llvm-project/mlir/lib/Conversion/BufferizationToMemRef/BufferizationToMemRef.cpp

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4.2 KiB
C++

//===- BufferizationToMemRef.cpp - Bufferization to MemRef conversion -----===//
//
// 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 file implements patterns to convert Bufferization dialect to MemRef
// dialect.
//
//===----------------------------------------------------------------------===//
#include "mlir/Conversion/BufferizationToMemRef/BufferizationToMemRef.h"
#include "../PassDetail.h"
#include "mlir/Dialect/Arithmetic/IR/Arithmetic.h"
#include "mlir/Dialect/Bufferization/IR/Bufferization.h"
#include "mlir/Dialect/MemRef/IR/MemRef.h"
#include "mlir/IR/BuiltinTypes.h"
#include "mlir/Support/LogicalResult.h"
#include "mlir/Transforms/DialectConversion.h"
using namespace mlir;
namespace {
/// The CloneOpConversion transforms all bufferization clone operations into
/// memref alloc and memref copy operations. In the dynamic-shape case, it also
/// emits additional dim and constant operations to determine the shape. This
/// conversion does not resolve memory leaks if it is used alone.
struct CloneOpConversion : public OpConversionPattern<bufferization::CloneOp> {
using OpConversionPattern<bufferization::CloneOp>::OpConversionPattern;
LogicalResult
matchAndRewrite(bufferization::CloneOp op, OpAdaptor adaptor,
ConversionPatternRewriter &rewriter) const override {
// Check for unranked memref types which are currently not supported.
Type type = op.getType();
if (type.isa<UnrankedMemRefType>()) {
return rewriter.notifyMatchFailure(
op, "UnrankedMemRefType is not supported.");
}
MemRefType memrefType = type.cast<MemRefType>();
MemRefLayoutAttrInterface layout;
auto allocType =
MemRefType::get(memrefType.getShape(), memrefType.getElementType(),
layout, memrefType.getMemorySpace());
// Since this implementation always allocates, certain result types of the
// clone op cannot be lowered.
if (!memref::CastOp::areCastCompatible({allocType}, {memrefType}))
return failure();
// Transform a clone operation into alloc + copy operation and pay
// attention to the shape dimensions.
Location loc = op->getLoc();
SmallVector<Value, 4> dynamicOperands;
for (int i = 0; i < memrefType.getRank(); ++i) {
if (!memrefType.isDynamicDim(i))
continue;
Value size = rewriter.createOrFold<arith::ConstantIndexOp>(loc, i);
Value dim =
rewriter.createOrFold<memref::DimOp>(loc, op.getInput(), size);
dynamicOperands.push_back(dim);
}
// Allocate a memref with identity layout.
Value alloc = rewriter.create<memref::AllocOp>(op->getLoc(), allocType,
dynamicOperands);
// Cast the allocation to the specified type if needed.
if (memrefType != allocType)
alloc = rewriter.create<memref::CastOp>(op->getLoc(), memrefType, alloc);
rewriter.replaceOp(op, alloc);
rewriter.create<memref::CopyOp>(loc, op.getInput(), alloc);
return success();
}
};
} // namespace
void mlir::populateBufferizationToMemRefConversionPatterns(
RewritePatternSet &patterns) {
patterns.add<CloneOpConversion>(patterns.getContext());
}
namespace {
struct BufferizationToMemRefPass
: public ConvertBufferizationToMemRefBase<BufferizationToMemRefPass> {
BufferizationToMemRefPass() = default;
void runOnOperation() override {
RewritePatternSet patterns(&getContext());
populateBufferizationToMemRefConversionPatterns(patterns);
ConversionTarget target(getContext());
target.addLegalDialect<memref::MemRefDialect>();
target.addLegalOp<arith::ConstantOp>();
target.addIllegalDialect<bufferization::BufferizationDialect>();
if (failed(applyPartialConversion(getOperation(), target,
std::move(patterns))))
signalPassFailure();
}
};
} // namespace
std::unique_ptr<Pass> mlir::createBufferizationToMemRefPass() {
return std::make_unique<BufferizationToMemRefPass>();
}