[PATCH] D31528: [ELF][MIPS] Multi-GOT implementation

[Rui Ueyama via llvm-commits]

I think I disagree. As I wrote there are still a lot of unnecessary
divergences from the other ELF standards in the MIPS ABI, and in a long
run, I believe these issues should be addressed, even if it means we need
more code in a (possibly long) transition period. I believe, for example,
we can agree that the very odd middle-endian header should have been fixed
like 10 years ago. I understand that it is of course not your fault. Who is
maintaining the MIPS ABI?

On Wed, Apr 26, 2017 at 3:17 AM, Simon Atanasyan <simon at atanasyan.com>
wrote:

> I do not think that hypothetical MIPS ABI will be _much_ _more_
> similar to other ABIs. For example, as to me I would keep MIPS GOT
> almost the same because it's efficient and works well. Even if a
> dynamic linker starts to recognize multi-GOT, that removes only a few
> lines of code from LLD. And during a long transition period we will
> have to support both variants. Special rules for .dynsym ordering and
> unsupported --hash-style=gnu are tightly related to MIPS GOT. There is
> an oddity in calculation addends for "paired" relocations (R_MIPS_HI16
> / R_MIPS_LO16) but we can consider this issue as fixed in N32 and N64
> ABI. Special sections like .reginfo, .MIPS.options, and .MIPS.abiflags
> are required to describe varieties of MIPS hardware. It's possible to
> rename default entry symbol s/__start/_start/, but it will not make
> LLD code much cleaner.
>
> In general, requirement to remove incompatibilities from MIPS ABI
> looks like a requirement to make MIPS ISA more similar to say X86 ISA
> for simplification of LLVM MC library code base. MIPS requires new ABI
> and finally I think it gets the new ABI, but I do not expect that this
> makes LLD code base smaller and cleaner.
>
> On Tue, Apr 25, 2017 at 7:37 PM, Rui Ueyama via llvm-commits
> <llvm-commits at lists.llvm.org> wrote:
> > Simon, can you start a discussion in the MIPS ABI mailing list (if
> exists)
> > that you are getting a push-back due to the incompatibilities from other
> ELF
> > standards?
>
> --
> Simon Atanasyan
>
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