[aarch64-port-dev ] RFR(M): 8196402: AARCH64: create intrinsic for Math.log

[Dmitry Samersoff]

Dmitrij,

This version of the fix looks good to me.

-Dmitry


On 06/01/2018 06:11 PM, Dmitrij Pochepko wrote:
> 
> 
> On 01.06.2018 16:45, Andrew Haley wrote:
>> On 05/21/2018 09:35 PM, Dmitrij Pochepko wrote:
>>>
>>> On 21.05.2018 17:45, Andrew Haley wrote:
>>>> On 05/21/2018 02:55 PM, Dmitrij Pochepko wrote:
>>>>> webrev: http://cr.openjdk.java.net/~dpochepk/8196402/webrev.01/
>>>>>
>>>>> CR: https://bugs.openjdk.java.net/browse/JDK-8196402
>>>> This looks basically reasonable, given that it seems to be a somewhat
>>>> straightforward adaptation of the x86 code.
>>>>     However, a couple of
>>>> things:
>>>>
>>>> The assembler changes should be parameterized as much as possible.
>>>> For example, fmlavvd, fmulxvsd, and fmulxssd are cases of the "AdvSIMD
>>>> vector x indexed element" class.  fmlavvd is a case of "AdvSIMD three
>>>> same", some of which already exist.  If you can extend an existing
>>>> group of instructions, please do.
>>> I couldn't merge new instructions with existing (encoding looks quite
>>> different), but I've managed to parametrize several new instructions
>>> into more compact code.
>> Looks much better.
>>
>>>> Given that this is an adaptation of the Intel code, please do two
>>>> things:
>>>>
>>>> Put it in the same place that corresponds to its position in the x86
>>>> files.
>>>>
>>>> Keep Intel's copyright.
>>> done.
>> And add your own.  With the current date:-)
> Ahh, forgot it. Thank you. Added.
>>
>>>> Thanks.
>>>>
>>> Please take a look at 2nd webrev:
>>> http://cr.openjdk.java.net/~dpochepk/8196402/webrev.02/
>>> I've tested modified patch with jdk jtreg tests.
>> This comment looks wrong:
>>
>>    41 //    Get B~1/mx based on the output of rcpss instruction (B0)
>>
>> Otherwise OK.
> Yes. You're right. For AARCH64 it's frecpe. Fixed comment.
>>
> Updated webrev:
> http://cr.openjdk.java.net/~dpochepk/8196402/webrev.03/
> 
> Thanks,
> Dmitrij


-- 
Dmitry Samersoff
http://devnull.samersoff.net
* There will come soft rains ...