2013-11-05  Marc Glisse  <marc.glisse@inria.fr>

gcc/
	* tree-ssa-alias.h (ranges_overlap_p): Handle negative offsets.
	* tree-ssa-alias.c (ao_ref_init_from_ptr_and_size): Likewise.

gcc/testsuite/
	* gcc.dg/tree-ssa/alias-26.c: New file.

From-SVN: r204388