RFR(XS): 8232106: [x86] C2: SIGILL due to usage of SSSE3 instructions on processors which don't support it

[Doerr, Martin]

Hi Tobias,

the instructions introduced by JDK-8222074 are leading to the crash we're seing.
But AddReductionVI uses phaddd which also belongs to SSSE3. So we should make these match rules unavailable for processors without SSSE3, too.

I have never seen crashes due to AddReductionVI, but I guess we should backport the fix to 11u, too.

Best regards,
Martin


> -----Original Message-----
> From: Tobias Hartmann <tobias.hartmann at oracle.com>
> Sent: Freitag, 11. Oktober 2019 10:25
> To: Doerr, Martin <martin.doerr at sap.com>; 'hotspot-compiler-
> dev at openjdk.java.net' <hotspot-compiler-dev at openjdk.java.net>
> Subject: Re: RFR(XS): 8232106: [x86] C2: SIGILL due to usage of SSSE3
> instructions on processors which don't support it
> 
> Hi Martin,
> 
> so this was introduced by JDK-8222074, right?
> 
> Just wondering, does AddReductionVI require SSSE3 as well?
> 
> Thanks,
> Tobias
> 
> On 10.10.19 14:29, Doerr, Martin wrote:
> > Hi,
> >
> > we have observed a JVM crash in JDK13u on an AMD Opteron machine.
> >
> > Instructions like pabsb/w/d, phaddd get emitted when SSE3 is available,
> but are not supported without SSSE3.
> > E.g. AMD Opteron(tm) Processor 2218 has SSE3, but not SSSE3.
> >
> > Should we fix it this way?
> > http://cr.openjdk.java.net/~mdoerr/8232106_x86_ssse3/webrev.00/
> >
> > Best regards,
> > Martin
> >