Method ProtectLoop

source/opt/loop_peeling.cpp:419–438

}

BasicBlock* LoopPeeling::ProtectLoop(Loop* loop, Instruction* condition,
                                     BasicBlock* if_merge) {
  BasicBlock* if_block = loop->GetOrCreatePreHeaderBlock();
  if (!if_block) {
    return nullptr;
  }
  // Will no longer be a pre-header because of the if.
  loop->SetPreHeaderBlock(nullptr);
  // Kill the branch to the header.
  context_->KillInst(&*if_block->tail());

  InstructionBuilder builder(
      context_, if_block,
      IRContext::kAnalysisDefUse | IRContext::kAnalysisInstrToBlockMapping);
  builder.AddConditionalBranch(condition->result_id(),
                               loop->GetHeaderBlock()->id(), if_merge->id(),
                               if_merge->id());

  return if_block;
}

bool LoopPeeling::PeelBefore(uint32_t peel_factor) {
  assert(CanPeelLoop() && "Cannot peel loop");