PR rtl-optimization/56151
	* optabs.c (add_equal_note): Don't return 0 if target is a MEM,
	equal to op0 or op1, and last_insn pattern is CODE operation
	with MEM dest and one of the operands matches that MEM.

	* gcc.target/i386/pr56151.c: New test.

Co-Authored-By: Steven Bosscher <steven@gcc.gnu.org>

From-SVN: r195972