//===----------------------------------------------------------------------===//
//
// 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
// Also available under a BSD-style license. See LICENSE.
//
//===----------------------------------------------------------------------===//

#include "PassDetail.h"

#include "mlir/Dialect/Func/IR/FuncOps.h"
#include "mlir/IR/BlockAndValueMapping.h"
#include "mlir/IR/Builders.h"
#include "mlir/Parser/Parser.h"
#include "mlir/Transforms/DialectConversion.h"
#include "mlir/Transforms/InliningUtils.h"
#include "torch-mlir/Dialect/Torch/IR/TorchDialect.h"
#include "torch-mlir/Dialect/Torch/IR/TorchOps.h"
#include "torch-mlir/Dialect/Torch/Transforms/Passes.h"
#include "torch-mlir/Dialect/Torch/Utils/Utils.h"
#include "llvm/ADT/StringExtras.h"
#include "llvm/ADT/StringSet.h"

using namespace mlir;
using namespace mlir::torch;
using namespace mlir::torch::Torch;

namespace {
class DropShapeCalculateOp : public OpConversionPattern<ShapeCalculateOp> {
public:
  using OpConversionPattern::OpConversionPattern;
  LogicalResult
  matchAndRewrite(ShapeCalculateOp op, OpAdaptor adaptor,
                  ConversionPatternRewriter &rewriter) const override {
    Block *block = &op.body().front();
    Operation *terminator = block->getTerminator();
    ValueRange results = terminator->getOperands();
    rewriter.mergeBlockBefore(block, op);
    rewriter.replaceOp(op, results);
    rewriter.eraseOp(terminator);
    return success();
  }
};
} // namespace

namespace {
class DropShapeCalculationsPass
    : public DropShapeCalculationsBase<DropShapeCalculationsPass> {
  void runOnOperation() override {
    MLIRContext *context = &getContext();

    RewritePatternSet patterns(context);
    patterns.insert<DropShapeCalculateOp>(context);
    ConversionTarget target(*context);
    target.addIllegalOp<ShapeCalculateOp>();
    target.addLegalOp<FuncOp>();

    if (failed(applyPartialConversion(getOperation(), target,
                                      std::move(patterns)))) {
      signalPassFailure();
    }
  }
};
} // namespace

std::unique_ptr<OperationPass<FuncOp>>
mlir::torch::Torch::createDropShapeCalculationsPass() {
  return std::make_unique<DropShapeCalculationsPass>();
}