RFR : 8218136: minor hotspot adjustments for xlclang++ from xlc16 on AIX

[Baesken, Matthias]

Hi Götz, new webrev :

http://cr.openjdk.java.net/~mbaesken/webrevs/8218136.4/


> The old xlc stuff is good to be removed.
> Could you please remove USE_XLC_PREFETCH_WRITE_BUILTIN
> altogether and replace its only use by USE_XLC_BUILTINS?
> 

Done .

> Also, I think it makes sense to put
>   #if __IBMCPP__ < 1000
>   #error "xlc < 10 not supported"
>   #endif
> into the file.
> 
> Probably we should even check for having at least xlc 12.

I added a check for xlc 12.  
Also  slightly changed the check for AIX  (_AIX macro)  in  globalDefinitions_xlc.hpp  .


> 
> The demangle fix is kind of preliminary, but to get the compiler
> working it is acceptable to skip this code for now.
>

There might be a fix for xlc16  in the future  but so far we have to live with it.


Best regards, Matthias



> -----Original Message-----
> From: Lindenmaier, Goetz
> Sent: Dienstag, 5. Februar 2019 09:59
> To: Baesken, Matthias <matthias.baesken at sap.com>; David Holmes
> <david.holmes at oracle.com>; 'hotspot-dev at openjdk.java.net' <hotspot-
> dev at openjdk.java.net>; 'magnus.ihse.bursie at oracle.com'
> <magnus.ihse.bursie at oracle.com>
> Cc: 'build-dev at openjdk.java.net' <build-dev at openjdk.java.net>
> Subject: RE: RFR : 8218136: minor hotspot adjustments for xlclang++ from
> xlc16 on AIX
> 
> Hi Matthias,
> 
> The demangle fix is kind of preliminary, but to get the compiler
> working it is acceptable to skip this code for now.
> 
> The old xlc stuff is good to be removed.
> Could you please remove USE_XLC_PREFETCH_WRITE_BUILTIN
> altogether and replace its only use by USE_XLC_BUILTINS?
> 
> Also, I think it makes sense to put
>   #if __IBMCPP__ < 1000
>   #error "xlc < 10 not supported"
>   #endif
> into the file.
> 
> Probably we should even check for having at least xlc 12.
> 
> Best regards,
>   Goetz.
> 
> > -----Original Message-----
> > From: hotspot-dev <hotspot-dev-bounces at openjdk.java.net> On Behalf
> Of
> > Baesken, Matthias
> > Sent: Montag, 4. Februar 2019 12:36
> > To: David Holmes <david.holmes at oracle.com>; 'hotspot-
> > dev at openjdk.java.net' <hotspot-dev at openjdk.java.net>;
> > 'magnus.ihse.bursie at oracle.com' <magnus.ihse.bursie at oracle.com>
> > Cc: 'build-dev at openjdk.java.net' <build-dev at openjdk.java.net>
> > Subject: RE: RFR : 8218136: minor hotspot adjustments for xlclang++ from
> > xlc16 on AIX
> >
> > Hi  David,  I  want to follow your suggestion 😊 .
> > I adjusted the comment , see  globalDefinitions_xlc.hpp  .
> >
> > Additionally I removed a  strange ifdef  handling pre-xlc10 versions  that are
> > not useful  today any more for OpenJDK
> > ( we  most likely cannot build jdk/jdk  with xlc versions < 10).
> >
> > New webrev :
> >
> > http://cr.openjdk.java.net/~mbaesken/webrevs/8218136.2/
> >
> >
> > Best regards, Matthias
> >
> >
> >
> > > -----Original Message-----
> > > From: David Holmes <david.holmes at oracle.com>
> > > Sent: Freitag, 1. Februar 2019 13:49
> > > To: Baesken, Matthias <matthias.baesken at sap.com>; 'hotspot-
> > > dev at openjdk.java.net' <hotspot-dev at openjdk.java.net>;
> > > 'magnus.ihse.bursie at oracle.com' <magnus.ihse.bursie at oracle.com>
> > > Cc: 'build-dev at openjdk.java.net' <build-dev at openjdk.java.net>
> > > Subject: Re: RFR : 8218136: minor hotspot adjustments for xlclang++ from
> > > xlc16 on AIX
> > >
> > > Hi Matthias,
> > >
> > > On 1/02/2019 10:36 pm, Baesken, Matthias wrote:
> > > > New webrev :
> > > >
> > > > http://cr.openjdk.java.net/~mbaesken/webrevs/8218136.1/
> > > >
> > > > - adjusted  globalDefinitions_xlc.hpp
> > >
> > > I don't think it makes sense to keep the comment which was obviously
> > > copied from the gcc file:
> > >
> > >   // On Linux NULL is defined as a special type '__null'. Assigning
> > > __null to
> > >    // integer variable will cause gcc warning. Use NULL_WORD in places
> > > where a
> > >    // pointer is stored as integer value.  On some platforms,
> > > sizeof(intptr_t) >
> > >    // sizeof(void*), so here we want something which is integer type,
> > > but has the
> > >    // same size as a pointer.
> > >
> > > Rather something like:
> > >
> > > // Some platform/tool-chain combinations can't assign NULL to an integer
> > > // type so we define NULL_WORD to use in those contexts. For xlc they
> > > // are the same.
> > >
> > > Thanks,
> > > David
> > >
> > >
>