[Bug other/37897] New: decNumber functions break strict-aliasing rules

["janis at gcc dot gnu dot org" <gcc-bugzilla@gcc.gnu.org>]

The decNumber package in GCC provides support for decimal floating point
arithmetic in the compiler and, for the DPD format, in libgcc's runtime support
for decimal float.  Some of the code in decNumber violates C's strict-aliasing
rules and has resulted in warnings for quite some time.  Some of that code has
different results since the addition of patch r136695, leading to the failure
of test gcc.dg/dfp/convert-int-max.c.  The code in question has undefined
behavior so I can't say that it is miscompiled, only that the results are
different.

I'm testing a patch that quiets all of the warnings about dereferencing
type-punned pointers with very few changes to the decNumber code, mostly
changes to data types and access macros.  This PR is to keep track of the
change because the decNumber code from GCC is also used by the GDB project and
a branch in EGLIBC.


-- 
           Summary: decNumber functions break strict-aliasing rules
           Product: gcc
           Version: 4.4.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: other
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: janis at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37897