[Bug optimization/12800] [tree-ssa] Store dropped after cast to pointer from integer of different size

["dnovillo at redhat dot com" <gcc-bugzilla at gcc dot gnu dot org>]

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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=12800



------- Additional Comments From dnovillo at redhat dot com  2003-10-28 01:07 -------
Subject: Re:  [tree-ssa] Store dropped after cast
	to pointer from integer of different size

On Mon, 2003-10-27 at 19:56, falk dot hueffner at student dot
uni-tuebingen dot de wrote:

> > > void op_stw_raw_T0_A0(int T2)
> > > {
> > >   *(char *) T2 = 0;
> > > }
> > > 
> > Why do you expect this to work?  T2 is an integer, not a pointer.
> 
> Well, the result of this is implementation defined, and gcc used to
> support converting pointers to numbers and back. Do you think this
> should be dropped?
>
Oh, bother.  So I guess we should support it.  The fix shouldn't be too
hard.  This is gimplified to

op_stw_raw_T0_A0 (T2)
{
  char * T2.1;

  T2.1 = (char *)T2;
  *T2.1 = 0;
}

The variable finder ought to mark T2.1 as a pointer to global memory. 
I'll assign this PR to me.


Diego.