Attribute Sync execution order

Is there any documentation available how the various gates before an attribute is sync’d? More specifically, what value is compared to the existing account attribute value before IDN decides it needs to be updated.

Scenario,
Identity Attribute - yyyy-MM-dd
Account attribute - 932481750328.z
Transform on the update provisioning policy for the attribute to convert it to the account attribute format, i.e
Transformed Identity Attribute Value - 932481750328.z

Question is, which value is compared to the account attribute value before IdentityNow decides whether to sync it or not? The Identity Attribute Value or the Transformed Identity Attribute Value from the provisioning policy.