× The internal search function is temporarily non-functional. The current search engine is no longer viable and we are researching alternatives.
As a stop gap measure, we are using Google's custom search engine service.
If you know of an easy to use, open source, search engine ... please contact support@midrange.com.



From: Alexei Pytel <pytel@us.ibm.com>
> > 2) the tagged pointer protection is not hardware, but is done in
> > software, so need not contribute to make memory more expensive.
>
> With all respect, the tagged pointer protection *is* hardware.
> It could in theory be done by software, but it would incur unacceptable
> overhead.
>

Well, the RISC code to check if a pointer is valid is:
LQ R6, addr  ;  load pointer into R6, R7. set bit in exception reg if no tag
TXER nn ; trap if no tag

to me that is software. The trap can be disabled by replacing the TXER
instruction by a NOOP.

The overhead is the TXER instruction and is not unacceptable.





As an Amazon Associate we earn from qualifying purchases.

This thread ...

Replies:

Follow On AppleNews
Return to Archive home page | Return to MIDRANGE.COM home page

This mailing list archive is Copyright 1997-2024 by midrange.com and David Gibbs as a compilation work. Use of the archive is restricted to research of a business or technical nature. Any other uses are prohibited. Full details are available on our policy page. If you have questions about this, please contact [javascript protected email address].

Operating expenses for this site are earned using the Amazon Associate program and Google Adsense.