PR rtl-optimization/63843
	* simplify-rtx.c (simplify_binary_operation_1) <case ASHIFTRT>: For
	optimization of ashiftrt of subreg of lshiftrt, check that code
	is ASHIFTRT.

	* gcc.c-torture/execute/pr63843.c: New test.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@217753 138bc75d-0d04-0410-961f-82ee72b054a4