2018-01-11  Martin Sebor  <msebor@gmail.com>
	    Prathamesh Kulkarni  <prathamesh.kulkarni@linaro.org>

	PR tree-optimization/83501
	PR tree-optimization/81703

	* tree-ssa-strlen.c (get_string_cst): Rename...
	(get_string_len): ...to this.  Handle global constants.
	(handle_char_store): Adjust.

testsuite/
	* gcc.dg/strlenopt-39.c: New test-case.
	* gcc.dg/pr81703.c: Likewise.

Co-Authored-By: Prathamesh Kulkarni <prathamesh.kulkarni@linaro.org>

From-SVN: r256475