> On May 2, 2023, at 9:18 AM, Roger Sayle <ro...@nextmovesoftware.com> wrote:
>
>
> On 02 May 2023 13:40, Paul Koning wrote:
>>> On May 1, 2023, at 7:37 PM, Roger Sayle <ro...@nextmovesoftware.com>
>> wrote:
>>>
>>> ...
>>> The shiftsi.cc regression on xstormy16 is fixed by adding
>>> -fno-split-wide-types.
>>> In fact, if all the regression tests pass, I'd suggest that
>>> flag_split_wide-types = false should be the default on xstormy16 now
>>> that we've moved to LRA. And if this works for xstormy16, it might be
>>> useful to other targets for the LRA transition; it's a difference in
>>> behaviour between reload and LRA that could potentially affect
>>> multiple targets.
>>
>> Is there documentation for that flag?
>
> Yes, see the section -fsplit-wide-types in
> https://gcc.gnu.org/onlinedocs/gcc/Optimize-Options.html
Thanks. So I'm wondering why that would be a problem.
The obvious question is whether it interacts badly with MD file entries that
describe wide operations, perhaps with constraints that require things like
odd/even register pairs. But I would assume all that gets handled.
Along the same lines, why would a target, or a user, not do early wide
splitting all the time? The documentation for that option gives no clue why it
would ever be bad.
paul
