Function GetBoolConstantKind

source/opt/folding_rules.cpp:3035–3061

}

std::optional<bool> GetBoolConstantKind(const analysis::Constant* c) {
  if (!c) {
    return {};
  }
  if (auto composite = c->AsCompositeConstant()) {
    auto& components = composite->GetComponents();
    if (components.empty()) {
      return {};
    }
    auto first = GetBoolConstantKind(components[0]);
    if (!first) {
      return {};
    }
    if (std::all_of(std::begin(components) + 1, std::end(components),
                    [first](const analysis::Constant* c2) {
                      return GetBoolConstantKind(c2) == first;
                    })) {
      return first;
    }
    return {};
  } else if (c->AsNullConstant()) {
    return false;
  } else if (c->AsBoolConstant()) {
    return c->AsBoolConstant()->value();
  }
  return {};
}

// Fold OpSelect instructions which have constant booleans as their result.
//   x ? true  : false =  x