Re: From LLVM: I got a note that LLVM plans to remove PPC64's V1 abi support; I'm asked about what support there is for the PPC64 little-endian/V2 abi (see forwarded message)

From: A. Wilcox <AWilcox_at_Wilcox-Tech.com>
Date: Wed, 28 Mar 2018 15:17:54 -0500
On 03/28/18 13:38, Nathan Whitehorn wrote:
> Is this big-endian support or V1 support being removed? We support 
> the V2 ABI fully on FreeBSD, but not (yet) little-endian. Like on 
> Linux, the default ABI on big-endian will likely remain V1 for the 
> indefinite future,

This is an important distinction to make (big-endian != ELFv1, and ELFv1
!= big-endian).

But do note that on Linux, the musl libc (in use by distros like Alpine,
Adélie, postmarketOS) only supports ELFv2, even in big-endian mode.  And
as the maintainer of Adélie using it as a daily-driver on an iMac G5,
it's definitely something you can use (the only breakage I've seen so
far on Linux is the PCRE JIT ignoring __CALL_ELF and inserting function
descriptors anyway).

So I wouldn't discount moving to ELFv2 ABI on BE if that is necessary to
keep LLVM happy.  It'd be some effort but it should work.

If this is really something FreeBSD is interested in, you might even
manage to convince me to put on my ports hat again, to help get the JIT
patches in that are needed for upstreams that went comatose.


Best,
--arw


> however, and it would be good if it were at least simple to re-add 
> support at some later date. -Nathan
> 

-- 
A. Wilcox (awilfox)
Open-source programmer (C, C++, Python)
https://code.foxkit.us/u/awilfox/


Received on Wed Mar 28 2018 - 18:24:17 UTC

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