Given that the C++ Standard has nothing to say about an ABI (neither does the C Standard, for that matter), then what a compiler does on a particular platform, and what a platform ABI specifies (if it does) are possibly kind of linked.
The word compiler is only mentioned 12 times in the whole standard give or take.
My point was that it's not a question of whether the compiler is modern or not, i.e. I work with an old compiler backend on a modern system and it still gets the ABI correct even if it ends up spilling back to memory too often.
