Vivado Synthesis can be run incrementally. In this flow, the tool will put incremental synthesis info in the generated DCP file that can be referenced in later runs. It will detect when the design has changed and then only re-run synthesis on sections of the design that have changed. The key advantage of this flow is that the run time will be significantly reduced for designs with small changes. In addition, the QoR of the design will fluctuate less when small changes are inserted into the RTL.