[Bug middle-end/36143] [4.4 Regression]: FAIL: g++.dg/tree-ssa/pr19637.C

[rguenther at suse dot de]

------- Comment #6 from rguenther at suse dot de  2008-05-06 10:22 -------
Subject: Re:  [4.4 Regression]: FAIL: g++.dg/tree-ssa/pr19637.C

On Tue, 6 May 2008, pinskia at gcc dot gnu dot org wrote:

> ------- Comment #5 from pinskia at gcc dot gnu dot org  2008-05-06 04:15 -------
> Oh we don't handle VCE On the left hand side for many different reasons.  One
> is because if we set only part of the variable, we could get possible invalid
> gimple as we are only setting part of a SSA_NAME.  I am un-assigning myself for
> now.

We fold

  i.1_7 = (struct Foo *) &i;
  D.2236_8 = i.1_7->i[0];

to

  D.2236_8 = VIEW_CONVERT_EXPR<struct Foo>(i).i[0];

which is fine in principle but misses a folding to i[0].  
maybe_fold_offset_to_{array,component}_ref in tree-ssa-ccp.c should
be extended to handle this case, invoked via fold_stmt.

Richard.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36143