This is the mail archive of the gcc-patches@gcc.gnu.org mailing list for the GCC project.

Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: [Patch, fortran] PR40011 - Problems with -fwhole-file

Richard Guenther wrote:
> I don't see how we could optimize the conditions
> as we have
> 
>   base.this = &j;
>   D.1550_9 = j.this;
>   D.1549_10 = D.1550_9 != &base;
>   D.1548_13 = D.1550_9 == 0B;
>   D.1547_14 = D.1548_13 | D.1549_10;
>   if (D.1547_14 != 0)
>     goto <bb 3>;
>   else
>     goto <bb 4>;
> 
> <bb 3>:
>   _gfortran_abort ();
> 
> where j is uninitialized (the stores to it have been optimized away
> before inlining).  Whether j.this != &base we cannot tell.

  Doesn't that mean that (at least in theory) we could invoke the leeway of
undefined behaviour and just assume whatever is convenient?

    cheers,
      DaveK
Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]