[zznzz]

Register renaming doesn’t significantly address the impact of reducing the number of architectural registers available to the compiler. With fewer register names available, the compiler will spill locals to stack more often, and register renaming doesn’t help - memory renaming is needed to really mitigate this.

But i agree the impact of preserving frame pointers is generally quite small and doesn’t often actually need mitigation - on amd64 there’s not much impact from losing 1 more of 16 arch registers.

[irogers]

Agner speaks about memory renaming back on Zen 2:

https://www.agner.org/forum/viewtopic.php?t=41

Intel Alderlake has performance events for tracking it:

https://github.com/intel/perfmon/blob/974c69919b2a9dfd8278cf...

But even before this you had store to load forwarding on x86. I'm not saying you have, but before inventing a performance problem it is worth spending time trying to diagnose it with thorough profiling (e.g. [1]). The Fedora frame pointer patch did a thorough performance analysis and performance will be revisited again. Unfortunately there are a lot of arm chair performance experts who haven't spent time looking into the details.

[1] https://perf.wiki.kernel.org/index.php/Top-Down_Analysis