Re: [Qemu-devel] [PATCH v3 17/27] tcg-ppc64: Implement bswap64

[Alexander Graf]

On 02.04.2013, at 06:23, Richard Henderson wrote:

> Reviewed-by: Aurelien Jarno <address@hidden>
> Signed-off-by: Richard Henderson <address@hidden>

Is this faster than a load/store with std/ldbrx?


Alex

> ---
> tcg/ppc64/tcg-target.c | 35 +++++++++++++++++++++++++++++++++++
> tcg/ppc64/tcg-target.h |  2 +-
> 2 files changed, 36 insertions(+), 1 deletion(-)
> 
> diff --git a/tcg/ppc64/tcg-target.c b/tcg/ppc64/tcg-target.c
> index d8131ec..1806364 100644
> --- a/tcg/ppc64/tcg-target.c
> +++ b/tcg/ppc64/tcg-target.c
> @@ -1706,6 +1706,40 @@ static void tcg_out_op (TCGContext *s, TCGOpcode opc, 
> const TCGArg *args,
>         }
>         break;
> 
> +    case INDEX_op_bswap64_i64:
> +        a0 = args[0], a1 = args[1], a2 = 0;
> +        if (a0 == a1) {
> +            a0 = 0;
> +            a2 = a1;
> +        }
> +
> +        /* a1 = # abcd efgh */
> +        /* a0 = rl32(a1, 8) # 0000 fghe */
> +        tcg_out_rlw(s, RLWINM, a0, a1, 8, 0, 31);
> +        /* a0 = dep(a0, rl32(a1, 24), 0xff000000) # 0000 hghe */
> +        tcg_out_rlw(s, RLWIMI, a0, a1, 24, 0, 7);
> +        /* a0 = dep(a0, rl32(a1, 24), 0x0000ff00) # 0000 hgfe */
> +        tcg_out_rlw(s, RLWIMI, a0, a1, 24, 16, 23);
> +
> +        /* a0 = rl64(a0, 32) # hgfe 0000 */
> +        /* a2 = rl64(a1, 32) # efgh abcd */
> +        tcg_out_rld(s, RLDICL, a0, a0, 32, 0);
> +        tcg_out_rld(s, RLDICL, a2, a1, 32, 0);
> +
> +        /* a0 = dep(a0, rl32(a2, 8), 0xffffffff)  # hgfe bcda */
> +        tcg_out_rlw(s, RLWIMI, a0, a2, 8, 0, 31);
> +        /* a0 = dep(a0, rl32(a2, 24), 0xff000000) # hgfe dcda */
> +        tcg_out_rlw(s, RLWIMI, a0, a2, 24, 0, 7);
> +        /* a0 = dep(a0, rl32(a2, 24), 0x0000ff00) # hgfe dcba */
> +        tcg_out_rlw(s, RLWIMI, a0, a2, 24, 16, 23);
> +
> +        if (a0 == 0) {
> +            tcg_out_mov(s, TCG_TYPE_I64, args[0], a0);
> +            /* Revert the source rotate that we performed above.  */
> +            tcg_out_rld(s, RLDICL, a1, a1, 32, 0);
> +        }
> +        break;
> +
>     default:
>         tcg_dump_ops (s);
>         tcg_abort ();
> @@ -1816,6 +1850,7 @@ static const TCGTargetOpDef ppc_op_defs[] = {
>     { INDEX_op_bswap16_i64, { "r", "r" } },
>     { INDEX_op_bswap32_i32, { "r", "r" } },
>     { INDEX_op_bswap32_i64, { "r", "r" } },
> +    { INDEX_op_bswap64_i64, { "r", "r" } },
> 
>     { -1 },
> };
> diff --git a/tcg/ppc64/tcg-target.h b/tcg/ppc64/tcg-target.h
> index bd011b8..d8e1820 100644
> --- a/tcg/ppc64/tcg-target.h
> +++ b/tcg/ppc64/tcg-target.h
> @@ -102,7 +102,7 @@ typedef enum {
> #define TCG_TARGET_HAS_ext32u_i64       1
> #define TCG_TARGET_HAS_bswap16_i64      1
> #define TCG_TARGET_HAS_bswap32_i64      1
> -#define TCG_TARGET_HAS_bswap64_i64      0
> +#define TCG_TARGET_HAS_bswap64_i64      1
> #define TCG_TARGET_HAS_not_i64          1
> #define TCG_TARGET_HAS_neg_i64          1
> #define TCG_TARGET_HAS_andc_i64         0
> -- 
> 1.8.1.4
>