Re: transmeta cpu code question

Jamie Lokier
2003-11-24T13:19:38Z

H. Peter Anvin wrote:
> If there is something that one could imagine doing at the CMS level to
> help on Linux, it would probably be something like making it optional
> to actually perform stores beneath the stack pointer, in which case a
> lot of stack frame operations could be done purely in registers. CMS
> will do them in registers already, but will be forced to perform a
> store at the end of the translation anyway in order to keep exact x86
> semantics.

You couldn't enable that globally, because it'd break userspace
programs which write below the stack safely using sigaltstack(), or
which even use the stack pointer as a general purpose register (I've
coded games which do that in tight rendering loops), or during funky
thunking code.

It sounds like a good thing to add as a per-task feature though.

-- Jamie