PR rtl-optimization/69891
	* dse.c (scan_insn): If we can't figure out memset arguments
	or they are non-constant, call clear_rhs_from_active_local_stores.

	* gcc.target/i386/pr69891.c: New test.

Co-Authored-By: Eric Botcazou <ebotcazou@adacore.com>

From-SVN: r233743