In principle if you are using the GP PRF it is possible to implement it so that there is little additional pressure: the store instruction already has it's data

In principle if you are using the GP PRF it is possible to implement it so that there is little additional pressure: the store instruction already has it's data input a register which has been renamed: now you just need to organize it so that the subsequent load that targets the same location is a no-go: simply alias the arch reg targeted by the load onto the existing register used by the store (much like mov-elimination) So except for a small window in the middle you have the same pressure on the PRF. I don't know if that is how it is actually implemented, of course!