Re: Stack bias

[der Mouse <mouse%Rodents-Montreal.ORG@localhost>]

>> I'm talking about whether routines that don't themselves need %sp
>> (which among other things pretty much compels them to be leaf
>> routines) can use %o6 the way they can use %o0-%o5 and %o7.
> No, leaf routines (those that don't issue save/restore instructions)

Okay, here is part of the confusion.  To me, a leaf routine is one that
does not call any others; depending on factors such as the complexity
of the routine and the smartness of the compiler, this may or may not
get compiled to code using save and restore.

I was actually talking about routines that _do_ save on entry and
restore on exit, but which have no desire to refer to %sp.  But, based
on what you say here, this is not safe because the kernel may want to
spill user windows onto the stack, and will assume %o6/%sp indicates
where to put them.  Have I finally got myself straightened out?

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