Re: [power7-meissner] Add __builtin_bswap{16,64} support to powerpc

[Richard Henderson <rth at redhat dot com>]

Michael Meissner wrote:
> +(define_expand "bswaphi2"
> +  [(use (match_operand:SI 0 "gpc_reg_operand" ""))
> +   (use (match_operand:SI 1 "gpc_reg_operand" ""))]
> +  "TARGET_POWERPC"
> +  {
> +    rtx inp = gen_reg_rtx (HImode);
> +    rtx out = gen_reg_rtx (HImode);
> +
> +    emit_move_insn (inp, simplify_gen_subreg (HImode, operands[1], SImode, 2));
> +    emit_insn (gen_bswaphi2_internal (out, inp));
> +    emit_insn (gen_zero_extendhisi2 (operands[0], out));
> +    DONE;
> +  })

Please don't put all this SImode nonsense in a pattern
that, by name and middle-end convention, is supposed to
operate on HImode values.

As for the non-existance of bswap16 as a generic builtin...
frankly I don't see why we can't add one for the sake of
consistency.


r~