On Fri, 30 Sep 2005, Andy Dougherty wrote:
> On Fri, 30 Sep 2005, Leopold Toetsch via RT wrote:
>
> > Andy Dougherty (via RT) wrote:
> >
> > > With a a fresh checkout (r9274) I get a number of errors where parrot
> > > eventually
> > > gobbles up all the memory on the system. Here's the first such one:
> > >
> > > t/op/gc........................
> > > # Failed test (t/op/gc.t at line 279)
> >
> > > # './parrot --gc-debug
> > > "/home/doughera/src/parrot/parrot-andy/t/op/gc_13.pir"' failed with exit
> > > code 131
> > > # Looks like you failed 1 test of 22.
> >
> > Strange. The test succeeds on linux/86 and OS/X 10.3 darwin. Running it
> > through valgrind on the linux box doesn't show any indication of an error.
Ok, I've finally found the cause of this one, but I don't have a portable
patch at hand.
Buried in amongst the 6827 warnings emitted by gcc is one that actually
correctly identifies the problem:
src/inter_create.c:400: warning: dereferencing type-punned pointer will
break strict-aliasing rules
And indeed that appears to be the problem. You can even reproduce the
problem under Linux/x86 with gcc-3.4 or newer. Simply compile with
optimization level of -O3.
The *temporary workaround* for *gcc only* is to supply gcc with the
-fno-strict-aliasing flag.
For those not familiar with aliasing, I found this article
http://mail-index.netbsd.org/tech-kern/2003/08/11/0001.html
to be useful. Another relevant page (specific to gcc) is at
http://gcc.gnu.org/bugs.html#nonbugs_c
Hope this helps,
--
Andy Dougherty [EMAIL PROTECTED]
