[11]RFR: 8203030: Zero s390 31 bit size_t type conflicts in shared code

[Dan Horák]

On Wed, 6 Jun 2018 17:15:17 -0400
Chris Phillips <ChrisPhi at LGonQn.Org> wrote:

> Hi Per,
> 
> On 06/06/18 04:47 PM, Per Liden wrote:
> > Hi Chris,
> > 
> > On 06/06/2018 09:36 PM, Chris Phillips wrote:
> >> Hi,
> >>
> >> On 06/06/18 02:23 PM, Per Liden wrote:
> >>> On 2018-06-06 18:29, Andrew Haley wrote:
> >>>> On 06/06/2018 04:47 PM, Chris Phillips wrote:
> >>>>> Please review this set of changes to shared code
> >>>>> related to S390 (31bit) Zero self-build type mis-match failures.
> >>>>>
> >>>>> Bug:    https://bugs.openjdk.java.net/browse/JDK-8203030
> >>>>> webrev:
> >>>>> http://cr.openjdk.java.net/~chrisphi/JDK-8203030/webrev.0
> >>>>
> >>>> Can you explain this a little more?  What is the type of size_t
> >>>> on s390x?  What is the type of uintptr_t?  What are the errors?
> >>>
> >>> I would like to understand this too.
> >>>
> >>> cheers,
> >>> Per
> >>>
> >>>
> >> Quoting from the original bug  review request:
> >> http://mail.openjdk.java.net/pipermail/hotspot-dev/2014-June/014254.html
> >> "This
> >> is a problem when one parameter is of size_t type and the second of
> >> uintx type and the platform has size_t defined as eg. unsigned
> >> long as on s390 (32-bit)."
> > 
> > Please clarify what the sizes of uintx (i.e. uintptr_t) and size_t
> > are on s390?
> See Dan's explanation.

the size is the same (32 bits), the problem is the definition


		Dan

> > 
> > I fail to see how any of this matters to _entries here? What am I
> > missing?
> > 
> 
> By changing the type, to its actual usage, we avoid the
> necessity of patching in
> src/hotspot/share/gc/g1/g1StringDedupTable.cpp around line 617, since
> its consistent usage and local I patched at the definition.
> 
> - _table->_entries, percent_of(_table->_entries, _table->_size),
> _entry_cache->size(), _entries_added, _entries_removed);
> + _table->_entries, percent_of( (size_t)(_table->_entries),
> _table->_size), _entry_cache->size(), _entries_added,
> _entries_removed);
> 
> percent_of will complain about types otherwise.
> 
> 
> > src/hotspot/share/gc/g1/g1StringDedupTable.hpp
> > @@ -120,11 +120,11 @@
> >    // Cache for reuse and fast alloc/free of table entries.
> >    static G1StringDedupEntryCache* _entry_cache;
> > 
> >    G1StringDedupEntry**            _buckets;
> >    size_t                          _size;
> > -  uintx                           _entries;
> > +  size_t                          _entries;
> >    uintx                           _shrink_threshold;
> >    uintx                           _grow_threshold;
> >    bool                            _rehash_needed;
> > 
> > cheers,
> > Per
> > 
> >>
> >> Hope that helps,
> >> Chris
> >>
> >> (I'll answer further if needed but the info is in the bugs and
> >> review thread mostly)
> >> See:
> >> https://bugs.openjdk.java.net/browse/JDK-8203030
> >> and:
> >> http://mail.openjdk.java.net/pipermail/hotspot-dev/2014-June/014254.html
> >> https://bugs.openjdk.java.net/browse/JDK-8046938
> >> https://bugs.openjdk.java.net/browse/JDK-8074459
> >> For more info.
> >>
> > 
> >