2011/5/11 Georg-Johann Lay <a...@gjlay.de>:
> Denis Chertykov schrieb:
>>
>> 2011/5/2 Georg-Johann Lay <a...@gjlay.de>:
>>
>>> This is a fix for an optimization flaw when a long value is composed
>>> from byte values.
>>>
>>> For -fsplit-wide-types (which is still default for avr) the code is
>>> worse than with -fno-split-wide-types. The code for the test case is
>>> better in either situations, i.e. compared to code without the patch,
>>> but it is still not optimal.
>>>
>>> Fixing this by some combine patterns is the only thing the BE can do.
>>> I did not write more complex patterns because things get too complex
>>> with little performance gain.
>>>
>>> Tested without regressions.
>>>
>>> Johann
>>>
>>> 2011-05-02 Georg-Johann Lay <a...@gjlay.de>
>>>
>>> PR target/27663
>>> * config/avr/predicates.md (const_8_16_24_operand): New predicate.
>>> * config/avr/avr.md ("*ior<mode>qi.byte0",
>>> "*ior<mode>qi.byte1-3"): New define_insn_and_split patterns.
>>>
>> I'm sorry, but I dot'n like to have a both combiner related patches in
>> port because code improvement isn't much and your patterns are
>> difficult to understand and maintain.
>>
>> May be somebody else have a different oppinion ?
>> I'm open to discussion.
>>
>> Denis.
>
> Let me add that the patch is generic enough to also improve ORing HI against
> QI like described in
>
> http://gcc.gnu.org/PR41076
>
> which is not uncommon on avr.
You right here.
Please, apply the patch.
Denis.
