simplify-rtx.c (simplify_unary_operation_1): We can strip zero_extend, bswap and...

simplify-rtx.c (simplify_unary_operation_1): We can strip zero_extend, bswap and rotates from POCOUNT's argument.

	* simplify-rtx.c (simplify_unary_operation_1) <POPCOUNT>: We can
	strip zero_extend, bswap and rotates from POCOUNT's argument.
	<PARITY>: Likewise, we can strip not, bswap, sign_extend,
	zero_extend and rotates from PARITY's argument.
	<BSWAP>: A byte-swap followed by a byte-swap is an identity.
	(simplify_const_unary_operation) <BSWAP>: Evaluate the byte-swap
	of an integer constant at compile-time.

	* gcc.target/i386/builtin-bswap-2.c: New test case.

From-SVN: r121716