* 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.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@121716 138bc75d-0d04-0410-961f-82ee72b054a4