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Re: Reload patch for PA call rewrite.
- From: "John David Anglin" <dave at hiauly1 dot hia dot nrc dot ca>
- To: law at redhat dot com
- Cc: rth at redhat dot com, gcc-patches at gcc dot gnu dot org
- Date: Fri, 15 Nov 2002 17:05:09 -0500 (EST)
- Subject: Re: Reload patch for PA call rewrite.
> In message <200210241848.g9OIm8b3026422@hiauly1.hia.nrc.ca>, "John David
> Anglin" writes:
> >As far as I can tell, we currently don't implement the branch target
> >stack feature. I can see that with my proposed PA2.0 additions to
> >various call sequences that this wouldn't be too hard to add.
> FWIW, most processors which have this capability do it implicitly -- the
> PA is the oddball here in that you have to enable the BTS by using
> special opcodes for the branch/return.
>
> Unfortunately I don't have information on what specific models of the PA8000
> series implement the branch target stack.
I have it from HP that there are no processors that implement the explicit
BTS opcodes described in the Kane book and that it is highly unlikely that
any future processors will have this feature. However, there are PA
processors have a completely hardware managed BTS.
Dave
--
J. David Anglin dave.anglin@nrc.ca
National Research Council of Canada (613) 990-0752 (FAX: 952-6605)