Anyone trying to answer this question would need to know the terms of the trust (by reviewing the governing document).
It is entirely possible for irrevocable trusts to be grantor trusts (or even partial grantor trusts).
In most instances, the trust receives a basis in the property that is stepped up to fair market value on the date of death of the grantor. Whether or not this occurs here is for a professional who can actually review the terms of the trust to determine.
You need to consult with a legal and/or tax professional who can read the governing document.
