Re: [PATCH] Implement PMC errata for MIPS

[Richard Sandiford <rdsandiford at googlemail dot com>]

Richard Sandiford <rdsandiford@googlemail.com> writes:
> "Moore, Catherine" <Catherine_Moore@mentor.com> writes:
>> This patch adds support for the -mfix-pmc option in binutils.  Does this
>> look okay to install?
>
> Looks good, thanks, but please run the testsuite for both a mips*-elf and a
> mips*-linux-gnu target.  mips*-linux-gnu aligns the text section to 16 bytes,
> and since the tests don't end on a 16-byte boudnary, they're likely to have
> more nops (or "..." instead of nops).
>
> One of the things you're testing is that we correctly add 3 nops after
> a final DMULTU, which is good, and definitely someting we should keep.
> That means we don't want to add .space to the end or use #pass, which
> are the usual ways of handling the alignment difference.  I think the
> best thing would be to add:
>
> 	.section .text2, "ax", @progbits
>         .align   2
>
> to the beginning of both tests so that we can pick our own alignment.
>
> There also needs to be some documentation in as.texinfo and c-mips.texi.

Sorry, forgot to say: AIUI this errata is specific to the RM7000.
Is that right?  Or does it apply to the RM9000 too?

If it's just the RM7000 then I think the option should be -mfix-rm7000
rather than -mfix-pmc.  We've generally named the -mfix options after
-march options where possible.

Thanks,
Richard