2012-08-22  Marc Glisse  <marc.glisse@inria.fr>

	PR tree-optimization/54317

gcc/
	* tree-vrp.c (extract_range_from_binary_expr_1): Test for
	double_int overflow.
	Remove dead tests.

gcc/testsuite/
	* gcc.dg/tree-ssa/vrp79.c: New testcase.

From-SVN: r190591