This is the mail archive of the
libc-alpha@sourceware.org
mailing list for the glibc project.
Re: [PATCH] MIPS: Use `.set arch=mips2' to emulate LL/SC for the R5900 too
- From: "Maciej W. Rozycki" <macro at linux-mips dot org>
- To: Fredrik Noring <noring at nocrew dot org>
- Cc: Joseph Myers <joseph at codesourcery dot com>, libc-alpha at sourceware dot org, Jürgen Urban <JuergenUrban at gmx dot de>
- Date: Sat, 27 Oct 2018 14:28:10 +0100 (BST)
- Subject: Re: [PATCH] MIPS: Use `.set arch=mips2' to emulate LL/SC for the R5900 too
- References: <9116ac0f611e7be2eea20602883d4955e8082c8b.1540641482.git.noring@nocrew.org>
Hi Fredrik,
> `.set arch=' was implemented in Binutils by Thiemo Seufer 29 June 2003 in
> commit fef14a42892a297bf, and the GNU C Library requires Binutils 2.25,
> from 2014, or later, so it ought to be compatible as used here.
>
> This change has been tested by compiling the GNU C Library 2.27 with a
> GCC 8.2.0 cross-compiler for mipsr5900el-unknown-linux-gnu under Gentoo.
Thank you for your contribution.
This change looks good if not obvious to me, however I think it would
make sense if you mentioned in the change description why you actually
need this to build for the R5900, i.e. quoted the lack of hardware LL/SC
instructions in the R5900 despite it matching `__mips >= 2', the build
errors you've still seen with `.set mips2', and the analysis of their
cause we have made off-list (which would serve as an explanation of the
difference between `.set mips2' and `.set arch=mips2', which is subtle
enough for someone coming across this change to wonder).
NB this change is legally insignificant enough WRT copyright to be
applied right away once we have consensus as per
<https://sourceware.org/glibc/wiki/Consensus> even while your paperwork
with FSF is (still) in progress.
Maciej