[aarch64-port-dev ] RFR: 8172881: AArch64: assertion failure: the int pressure is incorrect

[Andrew Haley]

On 23/01/17 09:02, Ningsheng Jian wrote:
> Hi Andrew,
> 
> On 22 January 2017 at 18:14, Andrew Haley <aph at redhat.com> wrote:
>> On 22/01/17 08:53, Ningsheng Jian wrote:
>>> http://cr.openjdk.java.net/~njian/8172881/webrev.00/
>>>
>>> Could you please help to review it? It passed jtreg tests.
>>
>> I don't understand why this patch works.  Do you?
> 
> I am also trying to understand why. At least this patch corrects the
> invalid reg class usage.
> 
> From my debugging, without the patch the get_and_setI gets the special
> reg R27. And seems that int_pressure is calculated before get_and_setI
> node's LRG regmask changes in
> PhaseChaitin::remove_bound_register_from_interfering_live_ranges. But
> I am not familiar with related code. I have tried to reduce the test
> case to http://cr.openjdk.java.net/~njian/8172881/test/test.tar.gz. It
> should be easier to reproduce this issue. Could you please have a try?

I think it would be safest at this stage to change both arguments to
iRegLNoSp.  Please try that.  It doesn't make any sense for either
argument to be in a special-purpose register.

Andrew.