Re: More on Lisp structures performance
"David McClain (as dbm at refined-audiometrics dot com)" <[email protected]>
| Newsgroups | gmane.lisp.lispworks.general |
|---|---|
| Message-ID | <[email protected]> |
I remember in the early days of RISC, that we could have literally hundreds of registers available in register banks or windows. These would get spilled out to stack memory en mass, one window at a time, and then reloaded as needed. When faced with so many registers it does become possible to mark out some of them for reserved uses. and so Reg vars might mean something. C.a., 1985 ?? But I do get your point about today. I actually have no direct experience writing ARM Assembly, and consider myself only vaguely competent at reading decompiled ARM code. For all prior generations of architectures I was an Assembly expert. But no more. > On Jan 23, 2026, at 11:36, Tim Bradshaw <[email protected]> wrote: > > On 23 Jan 2026, at 16:25, David McClain (as dbm at refined-audiometrics dot com) <[email protected]> wrote: >> >> What limits must we observe to ensure that the var remains in a register? > > You don't. You rely on the compiler to make decisions for you, because it is now the 20th century and good compilers exist. This is why, for instance, the 'register' keyword no longer exists in C++ and is pervasively ignored in C. The PDP-11 (let alone the PDP-7 where the keyword originated, in B) exists only in your mind. _______________________________________________ Lisp Hug - the mailing list for LispWorks users [email protected] http://www.lispworks.com/support/lisp-hug.html