2009-01-28  Richard Guenther  <rguenther@suse.de>

	PR tree-optimization/38926
	* tree-ssa-pre.c (add_to_value): Assert we add only expressions
	with the correct value id to a value.
	(do_regular_insertion): Use the value number of edoubleprime
	for the value number of the expr.

	Revert
	2008-08-21  Richard Guenther  <rguenther@suse.de>
  
        * tree-ssa-pre.c (insert_into_preds_of_block): Before inserting
        a PHI ask VN if it is already available.
        * tree-ssa-sccvn.h (vn_phi_lookup): Declare.
        * tree-ssa-sccvn.c (vn_phi_lookup): Export.

	* gcc.c-torture/compile/pr38926.c: New testcase.

From-SVN: r143725