PR rtl-optimization/46804
	* regmove.c (optimize_reg_copy_3): Look for REG_EQUAL note
	on the setter of src_reg rather than on insn.  If it is
	equal to the setter's original SET_SRC, replace it with its
	zero or sign extension instead of dropping it.

	* gfortran.dg/pr46804.f90: New test.

From-SVN: r167695