re PR tree-optimization/64705 (Bad code generation of sieve on x86-64 because of...

re PR tree-optimization/64705 (Bad code generation of sieve on x86-64 because of too aggressive IV optimizations)

	PR tree-optimization/64705
	* tree-ssa-loop-niter.h (expand_simple_operations): New parameter.
	* tree-ssa-loop-niter.c (expand_simple_operations): New parameter.
	* tree-ssa-loop-ivopts.c (extract_single_var_from_expr): New.
	(find_bivs, find_givs_in_stmt_scev): Pass new argument to
	expand_simple_operations.

	testsuite
	PR tree-optimization/64705
	* gcc.dg/tree-ssa/pr64705.c: New test.

From-SVN: r220676