Re: [kbuild-all] Re: [mips-linux:mips-next 98/101] arch/mips/include/asm/div64.h:74:3: error: inconsistent operand constraints in an 'asm'

[Rong Chen <rong.a.chen@intel.com>]

On 4/22/21 7:26 AM, Maciej W. Rozycki wrote:
> On Thu, 22 Apr 2021, kernel test robot wrote:
>
>>     fs/xfs/libxfs/xfs_alloc_btree.c: In function 'xfs_allocbt_free_block':
>>>> arch/mips/include/asm/div64.h:74:3: error: inconsistent operand constraints in an 'asm'
>>        74 |   __asm__("divu $0, %z1, %z2"    \
>>           |   ^~~~~~~
>   Umm, I forgot we do support MIPSr6, unlike microMIPSr6.
>
>   I think this asm can go and GCC will do equally well with plain C code.
> Or actually marginally better, as preliminary benchmarking shows, owing to
> a slightly better instruction scheduling.  Code produced for test_div64 is
> also slightly smaller for some reason.  That's at least for the ISAs up to
> R5, which do have DIVU.  Well, I can't complain.
>
>   For R6 compiled code will work, but separate DIVU and MODU instructions
> will be produced, which are also interlocked, so scalar implementations
> will likely not perform as well as older ISAs with their asynchronous MD
> unit.  Likely still faster then the generic algorithm though.
>
>   Thomas: I'll collect new figures and respin the series.  Please do drop
> the original series then; I think there's no point to fix it up and we'll
> be better by starting afresh.
>
>   Ying: I take it you'll know what to do to get the bot updated.  As it
> happens it uses the old <linux-mips@linux-mips.org> MIPS/Linux mailing
> list address, which has been long deprecated and then stopped working
> altogether mid Jan this year.  I have updated the cc appropriately with
> this reply, but would you please amend whatever the bot requires for
> further notices to be sent to <linux-mips@vger.kernel.org> instead?
>
>    Maciej

Hi Maciej,

Thanks for the advice, we have updated the mailing list.

Best Regards,
Rong Chen