void WasmBinaryBuilder::visitIf(If* curr) {
  BYN_TRACE("zz node: If\n");
  startControlFlow(curr);
  curr->type = getType();
  curr->condition = popNonVoidExpression();
  curr->ifTrue = getBlockOrSingleton(curr->type);
  if (lastSeparator == BinaryConsts::Else) {
    curr->ifFalse = getBlockOrSingleton(curr->type);
  }
  curr->finalize(curr->type);
  if (lastSeparator != BinaryConsts::End) {
    throwError("if should end with End");
  }
}