[aarch64-port-dev ] RFR: 8179933: aarch64: incorrect match rule for immL_63 and immL_255

[Ningsheng Jian]

Hi,

Is this patch OK for jdk10?

Thanks,
Ningsheng


On 15 May 2017 at 10:47, Zhongwei Yao <zhongwei.yao at linaro.org> wrote:
> Hi, Edward, Thanks for pointing out.
>
> And I've checked the generated nodes of dst = src / 2, (y and x are both
> long) in current c2 is:
>   RShiftL (AddL src (URShiftL (RShiftL src immI_63) immI_63))
>
> On 13 May 2017 at 02:11, Edward Nevill <edward.nevill at gmail.com> wrote:
>
>> On Fri, 2017-05-12 at 10:45 +0100, Andrew Dinn wrote:
>> > On 12/05/17 10:25, Andrew Haley wrote:
>> > >
>> > > On 12/05/17 10:14, Zhongwei Yao wrote:
>> > > >
>> > > > On 12 May 2017 at 16:14, Andrew Haley <aph at redhat.com> wrote:
>> > > > >
>> > > > > So it's
>> > > > >
>> > > > >    ((aLong >> 63) >>> 63)
>> > > > >
>> > > > > This is so weird I don't know what to think about it.
>> > > > Yeah, it is weird. I was thinking (aLong >>> 63) should be enough.
>> Shall we
>> > > > just remove this pattern?
>> > > Well, maybe there was a reason for it.
>> > Ok, these rules were first introduced into jdk8 by Ed Nevill
>> >
>> >   http://hg.openjdk.java.net/aarch64-port/jdk8u/hotspot/rev/1fcabae0e46f
>> >
>> > They were then imported into jdk9 as part of the wholesale upload.
>> >
>> > So, I think there is probably a good reason why they are there :-)
>> >
>>
>> Here is the original posting for the int case on aarch64-dev
>>
>> http://mail.openjdk.java.net/pipermail/aarch64-port-dev/
>> 2014-April/001047.html
>>
>> On Mon, 2014-05-12 at 13:10 +0100, Andrew Haley wrote:
>>
>> > Why is there no long version of this?
>>
>> So I added a long version
>>
>> http://mail.openjdk.java.net/pipermail/aarch64-port-dev/
>> 2014-May/001070.html
>>
>> Ed.
>>
>>
>
>
> --
> Best regards,
> Zhongwei