Method RewriteFunctionIntoSSA

source/opt/ssa_rewrite_pass.cpp:653–689

}

Pass::Status SSARewriter::RewriteFunctionIntoSSA(Function* fp) {
#if SSA_REWRITE_DEBUGGING_LEVEL > 0
  std::cerr << "Function before SSA rewrite:\n"
            << fp->PrettyPrint(0) << "\n\n\n";
#endif

  // Collect variables that can be converted into SSA IDs.
  pass_->CollectTargetVars(fp);

  // Generate all the SSA replacements and Phi candidates. This will
  // generate incomplete and trivial Phis.
  bool succeeded = pass_->cfg()->WhileEachBlockInReversePostOrder(
      fp->entry().get(), [this](BasicBlock* bb) {
        if (!GenerateSSAReplacements(bb)) {
          return false;
        }
        return true;
      });

  if (!succeeded) {
    return Pass::Status::Failure;
  }

  // Remove trivial Phis and add arguments to incomplete Phis.
  FinalizePhiCandidates();

  // Finally, apply all the replacements in the IR.
  bool modified = ApplyReplacements();

#if SSA_REWRITE_DEBUGGING_LEVEL > 0
  std::cerr << "\n\n\nFunction after SSA rewrite:\n"
            << fp->PrettyPrint(0) << "\n";
#endif

  return modified ? Pass::Status::SuccessWithChange
                  : Pass::Status::SuccessWithoutChange;
}

Pass::Status SSARewritePass::Process() {
  Status status = Status::SuccessWithoutChange;