5.1.1. Flow Summary Report
The Flow Summary section of the compilation report indicates whether the design exceeds the available device resources, and reports resource utilization, including pins, memory bits, digital signal processing (DSP) blocks, and phase-locked loops (PLLs).
The Fitter can spread logic throughout the device, which may lead to higher overall utilization.
As the device fills up, the Fitter automatically searches for logic functions with common inputs to place in one ALM. The number of packed registers also increases. Therefore, a design that has high overall utilization might still have space for extra logic if the logic and registers can be packed together more tightly. In those cases, you can benefit by a report that provides more details.