Re: Safe Pointers at the Intermediate Language or Hardware Level

On 2/10/2014 9:11 AM, seimarao@gmail.com wrote:
> Hi,
>
> Its been a long time since Java & .Net introduced safe address
> types to the computing world.
>
> My question is have we settled on what could be a proper representation
> for safe pointers ?
>
> Some Mainframes like the 390 have historically supported safe pointers,
> I remember.
>
> Sincerely,
> Seima Rao.
> [I looked at my S/390 Principles of Operation, and I see a bunch of stuff
> for tracing, but nothing that looks like safe pointers. I'd think it was
> hardware dependent, e.g., if a machine has a fairly clean and efficient
> trap for an unmapped zero address, you'd use that, but if it doesn't, you'd
> do something else. -John]
>


I'm an architect on the team doing the Mill CPU architecture
(ootbcomp.com/docs). We would love to do a full-blown capability system,
but regretfully have decided that's not viable as a commercial product.


A safe pointer (cap) is more than 64 bits, and people would refuse to
repeat the pain of the 32- to 64-bit migration. And most programs
violate safety (and language standards, but that's another issue), and
it's hard to make a sale when the customers keep saying "It worked on
Intel!".


Sad.

Return to the comp.compilers page.
Search the comp.compilers archives again.