Hi Kewen,

在 12/1/22 2:11 PM, Kewen.Lin 写道:
> on 2022/12/1 13:35, Jiufu Guo wrote:
>> Hi Kewen,
>>
>> Thanks for your quick and insight review!
>>
>> 在 12/1/22 1:17 PM, Kewen.Lin 写道:
>>> Hi Jeff,
>>>
>>> on 2022/12/1 09:36, Jiufu Guo wrote:
>>>> Hi,
>>>>
>>>> This patch just uses sext_hwi to replace the expression like:
>>>> ((value & 0xf..f) ^ 0x80..0) - 0x80..0 for rs6000.cc and rs6000.md.
>>>>
>>>> Bootstrap & regtest pass on ppc64{,le}.
>>>> Is this ok for trunk? 
>>>
>>> You didn't say it clearly but I guessed you have grepped in the whole
>>> config/rs6000 directory, right?  I noticed there are still two places
>>> using this kind of expression in function constant_generates_xxspltiw,
>>> but I assumed it's intentional as their types are not HOST_WIDE_INT.
>>>
>>> gcc/config/rs6000/rs6000.cc:      short sign_h_word = ((h_word & 0xffff) ^ 0x8000) - 0x8000;
>>> gcc/config/rs6000/rs6000.cc:  int sign_word = ((word & 0xffffffff) ^ 0x80000000) - 0x80000000;
>>>
>>> If so, could you state it clearly in commit log like "with type
>>> signed/unsigned HOST_WIDE_INT" or similar?
>>>
>> Good question!
>>
>> And as you said sext_hwi is more for "signed/unsigned HOST_WIDE_INT".
>> For these two places, it seems sext_hwi is not needed actually!
>> And I did see why these expressions are used, may be just an assignment
>> is ok.
> 
> ah, I see.  I agree using the assignment is quite enough.  Could you
> please also simplify them together?  Since they are with the form 
> "((value & 0xf..f) ^ 0x80..0) - 0x80..0" too, and can be refactored
> in a better way.  Thanks!

Sure, I believe just "short sign_h_word = vsx_const->half_words[0];"
should be correct :-), and included in the updated patch.

Updated patch is attached,  bootstrap&regtest is on going.


BR,
Jeff (Jiufu)

> 
> BR,
> Kewen
>