re PR tree-optimization/18529 (When the lower bound of a loop is non-constant we...

re PR tree-optimization/18529 (When the lower bound of a loop is non-constant we cannot find the number of iterations)

	PR tree-optimization/18529
	* fold-const.c (fold_to_nonsharp_ineq_using_bound): New function.
	(simple_operand_p): Use STRIP_NOPS.  Consider SSA names simple.
	(fold): Call fold_to_nonsharp_ineq_using_bound.
	* tree-ssa-loop-niter.c (simplify_replace_tree): New function.
	(number_of_iterations_cond): Fold the expressions before futher
	processing.
	(tree_simplify_using_condition): Handle case when cond or expr is
	an EQ_EXPR specially.

From-SVN: r91031