A match-action circuit includes one or more conditional logic circuits, each having an input coupled to input header or metadata of a network packet, and each configured to generate an enable signal as a function of one or more signals of the header or metadata. Each match circuit of one or more match circuits is configured with response values associated with key values. Each match circuit is configured to conditionally lookup response value(s) associated with an input key value from the header or metadata in response to the enable signal from a conditional logic circuit. One or more action circuits are configured to conditionally modify, in response to states of the response value(s) output from the match circuit(s), data of the header or the metadata.