The Vedic reduplicated deverbal nouns, such as cákri- “(who is) making”, are based on the perfect stem, and they parallel its semantic values as well: they indicate either the state of an Undergoer subject with regard to a particular event, or a property of an Actor subject performing an action.
More generally, the Vedic agent nouns (or nomina subjecti) parallel the values of their basic tense/aspectual verbal categories. Namely, the barytone (kártṛ-) and oxytone (kartŕ. -) derived nouns in -t- semantically correspond to the injunctive and the aorist respectively, whereas the reduplicated i stems (cákri-) correspond to the perfect. Throughout the history of the Vedic language, these nouns suffered the same fate as the corresponding verbal categories: the barytone nouns in -t- disappeared together with the injunctive, and the reduplicated nouns did not outlive the perfect.