Tools like that are a core part of the design process. You write that software along with the choice of parametrization of the design. It's not an off the shelf thing. But yes, that's how it works.

It's also important to note that decisions like this are hugely workload-specific. There's no single best processor for all applications. In extreme examples: almost every transistor on a vector SIMD unit is wasted when trying to optimize for a client Javascript benchmark; streaming symmetric encryption gets no benefit from L3 cache (which is like half the chip these days!); etc...