Method IsLoopInvariant

source/opt/scalar_analysis.cpp:375–394

}

bool ScalarEvolutionAnalysis::IsLoopInvariant(const Loop* loop,
                                              const SENode* node) const {
  for (auto itr = node->graph_cbegin(); itr != node->graph_cend(); ++itr) {
    if (const SERecurrentNode* rec = itr->AsSERecurrentNode()) {
      const BasicBlock* header = rec->GetLoop()->GetHeaderBlock();

      // If the loop which the recurrent expression belongs to is either |loop
      // or a nested loop inside |loop| then we assume it is variant.
      if (loop->IsInsideLoop(header)) {
        return false;
      }
    } else if (const SEValueUnknown* unknown = itr->AsSEValueUnknown()) {
      // If the instruction is inside the loop we conservatively assume it is
      // loop variant.
      if (loop->IsInsideLoop(unknown->ResultId())) return false;
    }
  }

  return true;
}

SENode* ScalarEvolutionAnalysis::GetCoefficientFromRecurrentTerm(
    SENode* node, const Loop* loop) {