RFR(S): 8220441: [PPC64] Clobber memory effect missing for memory barriers in atomics

[Lindenmaier, Goetz]

Hi Martin,

looks good to me.

Best regards,
  Goetz.

> -----Original Message-----
> From: Doerr, Martin
> Sent: Montag, 11. März 2019 17:05
> To: hotspot-runtime-dev at openjdk.java.net; Volker Simonis
> (volker.simonis at gmail.com) <volker.simonis at gmail.com>; Lindenmaier,
> Goetz <goetz.lindenmaier at sap.com>
> Subject: RFR(S): 8220441: [PPC64] Clobber memory effect missing for memory
> barriers in atomics
> 
> Hi,
> 
> 
> 
> the atomics in atomic_aix/linux_ppc.hpp use inline assembler memory
> barriers. They need a "clobber memory" effect in order to get handled
> correctly by C++ compilers.
> We haven't seen issues so far, but we should avoid problems with future
> compiler versions.
> 
> 
> 
> Please review
> 
> http://cr.openjdk.java.net/~mdoerr/8220441_ppc_clobber_mem/webrev.00/
> 
> 
> 
> Best regards,
> 
> Martin
> 
>