[PATCH v3 1/6] mips: Restrict the use of addiupc for microMIPSr6

[Philippe Mathieu-Daudé]

On 17/9/25 23:00, Adhemerval Zanella Netto wrote:
> On 17/09/25 17:51, H.J. Lu wrote:
>> On Wed, Sep 17, 2025 at 1:16 PM Adhemerval Zanella Netto
>> <adhemerval.zanella@linaro.org> wrote:

>>> On 03/09/25 10:53, Jovan Dmitrovic wrote:
>>>> For microMIPSr6, even though the ADDIUPC instruction is supported,
>>>> it requires for the address to be 4-byte aligned, which might not
>>>> be the case in all scenarios.
>>>
>>> The looks ok, although it is not clear to me if this is actually tested
>>> since it seems that mipsisa64r6el does not support -mmicromips. Should
>>> we add a mipsisa64r5el-linux-gnu target to build-many-glibcs.py?
>>>
>>> As a side note, it seems that mips16 is broken with --enable-profile
>>> or a long time and since 2.34 (035c012e32c11e84d64905efaf55e74f704d3668)
>>> without it:
>>>
>>> $ mips64-glibc-linux-gnu-gcc -mabi=32 -mips16 ../sysdeps/mips/start.S
>>> [...]
>>> libc/build/mips-linux-gnu-mips16/csu/start.o
>>> ../sysdeps/mips/start.S: Assembler messages:
>>> ../sysdeps/mips/start.S:147: Error: invalid operands `sw $0,16($sp)'
>>> [...]
>>>
>>> Should we remove mips16 support?
>>>
>>
>> Does mips16 support 32-bit displacement for TLS? If not, it may have the same
>> issue as ColdFire:
>>
>> https://sourceware.org/bugzilla/show_bug.cgi?id=33429
>>
> 
> I am not sure, maybe someone from htecgroup could answer. But it has been
> broken since 2021 without complains or bug reports.

4 years broken makes it hard to justify keeping it longer...