[Qemu-devel] Re: [PATCH 3/6] tcg: Optional target implementation of ANDC.

[Blue Swirl <blauwirbel@gmail.com>]

On Wed, Feb 17, 2010 at 12:10 AM, Richard Henderson <rth@twiddle.net> wrote:
> Previously ANDC was always implemented by tcg-op.h with
> an explicit NOT opcode.  Allow a target implementation.

I think the convention is to add commented out #defines or #undefs for
all targets, like sparc in bswap case:
//#define TCG_TARGET_HAS_bswap32_i32
//#define TCG_TARGET_HAS_bswap64_i64
or mips:
#undef TCG_TARGET_HAS_bswap32_i32
#undef TCG_TARGET_HAS_bswap16_i32

Then as each target maintainer decides whether it's a good idea to
implement the optional feature, the #undef can be changed to #define
as needed.

The same also applies to ORC patch (#4).

>
> Signed-off-by: Richard Henderson <rth@twiddle.net>
> ---
>  tcg/tcg-op.h  |   11 +++++++++++
>  tcg/tcg-opc.h |    6 ++++++
>  2 files changed, 17 insertions(+), 0 deletions(-)
>
> diff --git a/tcg/tcg-op.h b/tcg/tcg-op.h
> index 13eaa5a..447878d 100644
> --- a/tcg/tcg-op.h
> +++ b/tcg/tcg-op.h
> @@ -1650,20 +1650,31 @@ static inline void tcg_gen_concat32_i64(TCGv_i64 dest, TCGv_i64 low, TCGv_i64 hi
>
>  static inline void tcg_gen_andc_i32(TCGv_i32 ret, TCGv_i32 arg1, TCGv_i32 arg2)
>  {
> +#ifdef TCG_TARGET_HAS_andc_i32
> +    tcg_gen_op3_i32(INDEX_op_andc_i32, ret, arg1, arg2);
> +#else
>     TCGv_i32 t0;
>     t0 = tcg_temp_new_i32();
>     tcg_gen_not_i32(t0, arg2);
>     tcg_gen_and_i32(ret, arg1, t0);
>     tcg_temp_free_i32(t0);
> +#endif
>  }
>
>  static inline void tcg_gen_andc_i64(TCGv_i64 ret, TCGv_i64 arg1, TCGv_i64 arg2)
>  {
> +#ifdef TCG_TARGET_HAS_andc_i64
> +    tcg_gen_op3_i64(INDEX_op_andc_i64, ret, arg1, arg2);
> +#elif defined(TCG_TARGET_HAS_andc_i32) && TCG_TARGET_REG_BITS == 32
> +    tcg_gen_andc_i32(TCGV_LOW(ret), TCGV_LOW(arg1), TCGV_LOW(arg2));
> +    tcg_gen_andc_i32(TCGV_HIGH(ret), TCGV_HIGH(arg1), TCGV_HIGH(arg2));
> +#else
>     TCGv_i64 t0;
>     t0 = tcg_temp_new_i64();
>     tcg_gen_not_i64(t0, arg2);
>     tcg_gen_and_i64(ret, arg1, t0);
>     tcg_temp_free_i64(t0);
> +#endif
>  }
>
>  static inline void tcg_gen_eqv_i32(TCGv_i32 ret, TCGv_i32 arg1, TCGv_i32 arg2)
> diff --git a/tcg/tcg-opc.h b/tcg/tcg-opc.h
> index 89db3b4..6d855a7 100644
> --- a/tcg/tcg-opc.h
> +++ b/tcg/tcg-opc.h
> @@ -109,6 +109,9 @@ DEF2(not_i32, 1, 1, 0, 0)
>  #ifdef TCG_TARGET_HAS_neg_i32
>  DEF2(neg_i32, 1, 1, 0, 0)
>  #endif
> +#ifdef TCG_TARGET_HAS_andc_i32
> +DEF2(andc_i32, 1, 2, 0, 0)
> +#endif
>
>  #if TCG_TARGET_REG_BITS == 64
>  DEF2(mov_i64, 1, 1, 0, 0)
> @@ -185,6 +188,9 @@ DEF2(not_i64, 1, 1, 0, 0)
>  #ifdef TCG_TARGET_HAS_neg_i64
>  DEF2(neg_i64, 1, 1, 0, 0)
>  #endif
> +#ifdef TCG_TARGET_HAS_andc_i64
> +DEF2(andc_i64, 1, 2, 0, 0)
> +#endif
>  #endif
>
>  /* QEMU specific */
> --
> 1.6.2.5
>
>