//===- OperationSupport.cpp -----------------------------------------------===//
//
// Copyright 2019 The MLIR Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//   http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// =============================================================================
//
// This file contains out-of-line implementations of the support types that
// Operation and related classes build on top of.
//
//===----------------------------------------------------------------------===//

#include "mlir/IR/OperationSupport.h"
#include "mlir/IR/Block.h"
#include "mlir/IR/Operation.h"
using namespace mlir;

//===----------------------------------------------------------------------===//
// OperationState
//===----------------------------------------------------------------------===//

OperationState::OperationState(Location location, StringRef name)
    : location(location), name(name, location->getContext()) {}

OperationState::OperationState(Location location, OperationName name)
    : location(location), name(name) {}

OperationState::OperationState(Location location, StringRef name,
                               ValueRange operands, ArrayRef<Type> types,
                               ArrayRef<NamedAttribute> attributes,
                               ArrayRef<Block *> successors,
                               MutableArrayRef<std::unique_ptr<Region>> regions,
                               bool resizableOperandList)
    : location(location), name(name, location->getContext()),
      operands(operands.begin(), operands.end()),
      types(types.begin(), types.end()),
      attributes(attributes.begin(), attributes.end()),
      successors(successors.begin(), successors.end()) {
  for (std::unique_ptr<Region> &r : regions)
    this->regions.push_back(std::move(r));
}

void OperationState::addOperands(ValueRange newOperands) {
  assert(successors.empty() && "Non successor operands should be added first.");
  operands.append(newOperands.begin(), newOperands.end());
}

void OperationState::addSuccessor(Block *successor, ValueRange succOperands) {
  successors.push_back(successor);
  // Insert a sentinel operand to mark a barrier between successor operands.
  operands.push_back(nullptr);
  operands.append(succOperands.begin(), succOperands.end());
}

Region *OperationState::addRegion() {
  regions.emplace_back(new Region);
  return regions.back().get();
}

void OperationState::addRegion(std::unique_ptr<Region> &&region) {
  regions.push_back(std::move(region));
}

//===----------------------------------------------------------------------===//
// OperandStorage
//===----------------------------------------------------------------------===//

/// Replace the operands contained in the storage with the ones provided in
/// 'operands'.
void detail::OperandStorage::setOperands(Operation *owner,
                                         ValueRange operands) {
  // If the number of operands is less than or equal to the current amount, we
  // can just update in place.
  if (operands.size() <= numOperands) {
    auto opOperands = getOperands();

    // If the number of new operands is less than the current count, then remove
    // any extra operands.
    for (unsigned i = operands.size(); i != numOperands; ++i)
      opOperands[i].~OpOperand();

    // Set the operands in place.
    numOperands = operands.size();
    for (unsigned i = 0; i != numOperands; ++i)
      opOperands[i].set(operands[i]);
    return;
  }

  // Otherwise, we need to be resizable.
  assert(resizable && "Only resizable operations may add operands");

  // Grow the capacity if necessary.
  auto &resizeUtil = getResizableStorage();
  if (resizeUtil.capacity < operands.size())
    grow(resizeUtil, operands.size());

  // Set the operands.
  OpOperand *opBegin = getRawOperands();
  for (unsigned i = 0; i != numOperands; ++i)
    opBegin[i].set(operands[i]);
  for (unsigned e = operands.size(); numOperands != e; ++numOperands)
    new (&opBegin[numOperands]) OpOperand(owner, operands[numOperands]);
}

/// Erase an operand held by the storage.
void detail::OperandStorage::eraseOperand(unsigned index) {
  assert(index < size());
  auto operands = getOperands();
  --numOperands;

  // Shift all operands down by 1 if the operand to remove is not at the end.
  auto indexIt = std::next(operands.begin(), index);
  if (index != numOperands)
    std::rotate(indexIt, std::next(indexIt), operands.end());
  operands[numOperands].~OpOperand();
}

/// Grow the internal operand storage.
void detail::OperandStorage::grow(ResizableStorage &resizeUtil,
                                  size_t minSize) {
  // Allocate a new storage array.
  resizeUtil.capacity =
      std::max(size_t(llvm::NextPowerOf2(resizeUtil.capacity + 2)), minSize);
  OpOperand *newStorage = static_cast<OpOperand *>(
      llvm::safe_malloc(resizeUtil.capacity * sizeof(OpOperand)));

  // Move the current operands to the new storage.
  auto operands = getOperands();
  std::uninitialized_copy(std::make_move_iterator(operands.begin()),
                          std::make_move_iterator(operands.end()), newStorage);

  // Destroy the original operands and update the resizable storage pointer.
  for (auto &operand : operands)
    operand.~OpOperand();
  resizeUtil.setDynamicStorage(newStorage);
}

//===----------------------------------------------------------------------===//
// Operation Value-Iterators
//===----------------------------------------------------------------------===//

//===----------------------------------------------------------------------===//
// OperandRange

OperandRange::OperandRange(Operation *op)
    : OperandRange(op->getOpOperands().data(), op->getNumOperands()) {}

//===----------------------------------------------------------------------===//
// ResultRange

ResultRange::ResultRange(Operation *op)
    : ResultRange(op->getOpResults().data(), op->getNumResults()) {}

//===----------------------------------------------------------------------===//
// ValueRange

ValueRange::ValueRange(ArrayRef<Value *> values)
    : ValueRange(values.data(), values.size()) {}
ValueRange::ValueRange(OperandRange values)
    : ValueRange(values.begin().getBase(), values.size()) {}
ValueRange::ValueRange(ResultRange values)
    : ValueRange(values.begin().getBase(), values.size()) {}

/// See `detail::indexed_accessor_range_base` for details.
ValueRange::OwnerT ValueRange::offset_base(const OwnerT &owner,
                                           ptrdiff_t index) {
  if (OpOperand *operand = owner.dyn_cast<OpOperand *>())
    return operand + index;
  if (OpResult *result = owner.dyn_cast<OpResult *>())
    return result + index;
  return owner.get<Value *const *>() + index;
}
/// See `detail::indexed_accessor_range_base` for details.
Value *ValueRange::dereference_iterator(const OwnerT &owner, ptrdiff_t index) {
  // Operands access the held value via 'get'.
  if (OpOperand *operand = owner.dyn_cast<OpOperand *>())
    return operand[index].get();
  // An OpResult is a value, so we can return it directly.
  if (OpResult *result = owner.dyn_cast<OpResult *>())
    return &result[index];
  // Otherwise, this is a raw value array so just index directly.
  return owner.get<Value *const *>()[index];
}