On 15 Oct 2001, Brian Wheeler wrote:
> With the addition of clone, I started writing some generic routines
> which might be useful (index,lc,uc,reverse,abs,tr,etc)...and I came
> across some weirdness:
>
> doing:
> save S0
> restore S1
>
> (since there's no set S1,S0)
>
> binds the registers together, so a change to one is a change to
> both...which doesn't happen on int registers.
Right. Save on a string register pushes the pointer to the string
structure in the register onto the stack. The same thing happens with
PMCs, or will when they're implemented.
The assumption is that, when you push a register onto the stack, you'll
then stomp on the contents of the register. (Rather than what the register
points to...) Otherwise a push would need to create a copy of the string
structure and a copy of the string contents.
Dan
