This is the mail archive of the
mailing list for the binutils project.
Re: OR_AND semantics (was: GNU property saga)
On Thu, Mar 7, 2019 at 10:06 PM Cary Coutant <email@example.com> wrote:
> > > Now the above language would include FEATURE_X in the output, but bit 4
> > > would be reliable (set a.bit4 && b.bit4) while bit 5 would be
> > > (it is zero, even if it is one in a.o and _would_ be one in b.o had we
> > > used a newer producer).
> > We can't add a bit to FEATURE_X in such a way that FEATURE_X generated
> > by older producers become invalid. We must add the bit to FEATURE_Y
> which is
> > unsupported to all prior producers. Am I missing something obvious?
> Yes, I think so. This is the point Michael (and I) were making. By
> using KNOWN bits, you can add new feature bits without having to start
> a whole new word of bits.
You also don't need to assume that a producer that has implemented support
for the tenth feature bit is also generating valid values for the
previously-defined nine, just because the words containing them are present.
> You received this message because you are subscribed to the Google Groups
> "X86-64 System V Application Binary Interface" group.
> To unsubscribe from this group and stop receiving emails from it, send an
> email to firstname.lastname@example.org.
> For more options, visit https://groups.google.com/d/optout.