Re: [PATCH 3/4] [ARC] Remove NPS-400 as a machine type

[Graham Markall <graham dot markall at embecosm dot com>]

Hi Nick,

> I am not sure that this patch is a good idea.  What happens if the tools
> (readelf, objcopy, objdump, etc) are used on an old binary that still has
> the old E_ARC_MACH_NPS400 value set in the ELF flag bits ?  Presumably they
> won't recognise it.  If there is a possibility that these old binaries exist
> then we must maintain backwards compatibility for them.

I think that the possibility that there are existing binaries around
that use the E_ARC_MACH_NPS400 value is quite remote - this value was
only added recently (since the 2.26 release). I think that for someone
to have created NPS-400 binaries with this value, they would have had to
have checked out and built from binutils master, but I don't think this
is likely since the implementation for NPS-400 in master is still
incomplete (missing many instructions). Because of this, anyone needing
to build code for an NPS-400 will be using an implementation of the
toolchain provided by Mellanox/EZChip, which never generated binaries
with the E_ARC_MACH_NPS400 value - it always used the E_ARC_MACH_ARC700
value.

With that in mind, I was hoping that we could correct this "mistake" of
ever adding E_ARC_MACH_NPS400 before the next release, so that there
isn't a release version that ever generates binaries with this value.
Given the current situation, could it still be appropriate to remove the
E_ARC_MACH_NPS400 value?


Many thanks,
Graham.

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