Method Simplify

source/opt/scalar_analysis_simplification.cpp:197–239

}

SENode* SENodeSimplifyImpl::Simplify() {
  // We only handle graphs with an addition, multiplication, or negation, at the
  // root.
  if (node_->GetType() != SENode::Add && node_->GetType() != SENode::Multiply &&
      node_->GetType() != SENode::Negative)
    return node_;

  SENode* simplified_polynomial = SimplifyPolynomial();

  SERecurrentNode* recurrent_expr = nullptr;
  node_ = simplified_polynomial;

  // Fold recurrent expressions which are with respect to the same loop into a
  // single recurrent expression.
  simplified_polynomial = FoldRecurrentAddExpressions(simplified_polynomial);

  simplified_polynomial =
      EliminateZeroCoefficientRecurrents(simplified_polynomial);

  // Traverse the immediate children of the new node to find the recurrent
  // expression. If there is more than one there is nothing further we can do.
  for (SENode* child : simplified_polynomial->GetChildren()) {
    if (child->GetType() == SENode::RecurrentAddExpr) {
      recurrent_expr = child->AsSERecurrentNode();
    }
  }

  // We need to count the number of unique recurrent expressions in the DAG to
  // ensure there is only one.
  for (auto child_iterator = simplified_polynomial->graph_begin();
       child_iterator != simplified_polynomial->graph_end(); ++child_iterator) {
    if (child_iterator->GetType() == SENode::RecurrentAddExpr &&
        recurrent_expr != child_iterator->AsSERecurrentNode()) {
      return simplified_polynomial;
    }
  }

  if (recurrent_expr) {
    return SimplifyRecurrentAddExpression(recurrent_expr);
  }

  return simplified_polynomial;
}

// Traverse the graph to build up the accumulator objects.
void SENodeSimplifyImpl::GatherAccumulatorsFromChildNodes(SENode* new_node,