Function try_normalized_program_cache_digest 

pub fn try_normalized_program_cache_digest(
    program: &Program,
) -> Result<[u8; 32], String>

Return the normalized program digest used by backend pipeline caches.

Errors

Returns when the program contains an IR type or node shape that cannot be serialized into stable cache identity. Dispatch admission should surface the error rather than panic or generate a lossy cache key.