Method IsConditionCheckSideEffectFree

source/opt/loop_peeling.cpp:232–266

}

bool LoopPeeling::IsConditionCheckSideEffectFree() const {
  CFG& cfg = *context_->cfg();

  // The "do-while" form does not cause issues, the algorithm takes into account
  // the first iteration.
  if (!do_while_form_) {
    uint32_t condition_block_id = cfg.preds(loop_->GetMergeBlock()->id())[0];

    std::unordered_set<uint32_t> blocks_in_path;

    blocks_in_path.insert(condition_block_id);
    GetBlocksInPath(condition_block_id, loop_->GetHeaderBlock()->id(),
                    &blocks_in_path, cfg);

    for (uint32_t bb_id : blocks_in_path) {
      BasicBlock* bb = cfg.block(bb_id);
      if (!bb->WhileEachInst([this](Instruction* insn) {
            if (insn->IsBranch()) return true;
            switch (insn->opcode()) {
              case spv::Op::OpLabel:
              case spv::Op::OpSelectionMerge:
              case spv::Op::OpLoopMerge:
                return true;
              default:
                break;
            }
            return context_->IsCombinatorInstruction(insn);
          })) {
        return false;
      }
    }
  }

  return true;
}

void LoopPeeling::GetIteratingExitValues() {
  CFG& cfg = *context_->cfg();