On Sunday, 12 November 2017 at 22:20:46 UTC, Dibyendu Majumdarno in naked mode you have to save and restore by hand.
Note that in Win64 even if not naked, you'll have to save/restore some registers like XMMx with x >= 6.
Another question - how can I tell DMD to no generate the frame pointer?
naked;However with naked; you have the problem of respecting the various ABI out there.