cfg-node.cpp

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/*
 * Copyright 2014 Helge Bahmann <hcb@chaoticmind.net>
 * Copyright 2013 2014 2015 Nico Reißmann <nico.reissmann@gmail.com>
 * See COPYING for terms of redistribution.
 */
 
#include <jlm/llvm/ir/basic-block.hpp>
#include <jlm/llvm/ir/ipgraph.hpp>
 
namespace jlm::llvm
{
 
ControlFlowGraphEdge::ControlFlowGraphEdge(
    ControlFlowGraphNode * source,
    ControlFlowGraphNode * sink,
    size_t index) noexcept
    : source_(source),
      sink_(sink),
      index_(index)
{}
 
void
ControlFlowGraphEdge::divert(ControlFlowGraphNode * new_sink)
{
  if (sink_ == new_sink)
    return;
 
  sink_->inedges_.erase(this);
  sink_ = new_sink;
  new_sink->inedges_.insert(this);
}
 
BasicBlock *
ControlFlowGraphEdge::split()
{
  auto sink = sink_;
  auto bb = BasicBlock::create(source_->cfg());
  divert(bb);
  bb->add_outedge(sink);
  return bb;
}
 
ControlFlowGraphNode::~ControlFlowGraphNode() noexcept = default;
 
size_t
ControlFlowGraphNode::NumOutEdges() const noexcept
{
  return outedges_.size();
}
 
void
ControlFlowGraphNode::remove_inedges()
{
  while (inedges_.size() != 0)
  {
    ControlFlowGraphEdge * edge = *inedges_.begin();
    JLM_ASSERT(edge->sink() == this);
    edge->source()->remove_outedge(edge->index());
  }
}
 
size_t
ControlFlowGraphNode::NumInEdges() const noexcept
{
  return inedges_.size();
}
 
bool
ControlFlowGraphNode::no_predecessor() const noexcept
{
  return NumInEdges() == 0;
}
 
bool
ControlFlowGraphNode::single_predecessor() const noexcept
{
  if (NumInEdges() == 0)
    return false;
 
  for (auto i = inedges_.begin(); i != inedges_.end(); i++)
  {
    JLM_ASSERT((*i)->sink() == this);
    if ((*i)->source() != (*inedges_.begin())->source())
      return false;
  }
 
  return true;
}
 
bool
ControlFlowGraphNode::no_successor() const noexcept
{
  return NumOutEdges() == 0;
}
 
bool
ControlFlowGraphNode::single_successor() const noexcept
{
  if (NumOutEdges() == 0)
    return false;
 
  for (auto & edge : OutEdges())
  {
    JLM_ASSERT(edge.source() == this);
    if (edge.sink() != OutEdge(0)->sink())
      return false;
  }
 
  return true;
}
 
bool
ControlFlowGraphNode::has_selfloop_edge() const noexcept
{
  for (auto & edge : OutEdges())
  {
    if (edge.is_selfloop())
      return true;
  }
 
  return false;
}
 
}