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From: Paul C. Leopardi (paul.leopardi_at_[hidden])
Date: 2008-03-21 02:04:14
On Mon, 17 Mar 2008, Jens Seidel wrote:
> On Sun, Mar 16, 2008 at 05:42:38PM +1100, Paul C. Leopardi wrote:
> > On Sun, 16 Mar 2008, Paul C. Leopardi wrote:
> > > Hi all,
> > > I'm getting strange results (below) with iterators in
> > > storage_sparse.hpp and was wondering if this was a know issue in gcc
> > > 4.3.0?
> >
> > I've narrowed the bug down to a few lines of operator*= in
> > matrix_mult_imp.h in my own GluCat code:
> >
> > 440 // Operate only within a common frame
> > 441 const index_set_t our_frame = lhs.m_frame | rhs.m_frame;
> > 442 const multivector_t& lhs_ref = (lhs.m_frame == our_frame)
> > 443 ? lhs
> > 444 : multivector_t(framed_multi_t(lhs), our_frame, true);
> > 445 const multivector_t& rhs_ref = (rhs.m_frame == our_frame)
> > 446 ? rhs
> > 447 : multivector_t(framed_multi_t(rhs), our_frame, true);
> >
> > Here multivector_t is a class containing a member of type
> > ublas::compressed_matrix< Scalar_T, orientation_t >.
> >
> > When I change const multivector_t& rhs_ref to const multivector_t rhs_ref
> > the code works. This looks like a compiler bug to me.
>
> The code looks legal C++ code under the assumption that the type
> multivector_t has a copy contructor which is required (compare e.g.
> http://www.gnu.org/software/gcc/bugs.html, "Copy constructor access
> check while initializing a reference."). Otherwise you should also get
> a compile time error ...
Thanks Jens,
I've apparently found the bug.
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=35548
I applied the patch
http://gcc.gnu.org/viewcvs?view=rev&revision=133300
to cp/call.c in my copy of gcc 4.3.0 and re-made and re-ran test11.
It worked!
Best, Paul