[CamelCaseCondo]

op is probably referring to the push all/pop all approach.

[Joker_vD]

No, I don't. I use a common "spill definitely reused call-invariant registers at the prologue, spill call-clobbered registers that need to survive a call at precisely the call site" approach, see the sibling comment for the arithmetic.

[saagarjha]

That’s the push all/pop all approach.