Re: [Qemu-devel] [PATCH v2 07/27] tcg-ppc64: Cleanup tcg_out_movi

[Aurelien Jarno]

On Mon, Mar 04, 2013 at 04:32:50PM -0800, Richard Henderson wrote:
> The test for using movi32 was sub-optimal for TCG_TYPE_I32, comparing
> a signed 32-bit quantity against an unsigned 32-bit quantity.
> 
> When possible, use addi+oris for 32-bit unsigned constants.  Otherwise,
> standardize on addi+oris+ori instead of addis+ori+rldicl.
> 
> Signed-off-by: Richard Henderson <address@hidden>
> ---
>  tcg/ppc64/tcg-target.c | 36 ++++++++++++++++--------------------
>  1 file changed, 16 insertions(+), 20 deletions(-)
> 
> diff --git a/tcg/ppc64/tcg-target.c b/tcg/ppc64/tcg-target.c
> index 82e1da7..a4951c5 100644
> --- a/tcg/ppc64/tcg-target.c
> +++ b/tcg/ppc64/tcg-target.c
> @@ -477,29 +477,25 @@ static void tcg_out_movi32(TCGContext *s, TCGReg ret, 
> int32_t arg)
>      }
>  }
>  
> -static void tcg_out_movi (TCGContext *s, TCGType type,
> -                          TCGReg ret, tcg_target_long arg)
> +static void tcg_out_movi(TCGContext *s, TCGType type, TCGReg ret,
> +                         tcg_target_long arg)
>  {
> -    int32_t arg32 = arg;
> -    arg = type == TCG_TYPE_I32 ? arg & 0xffffffff : arg;
> -
> -    if (arg == arg32) {
> -        tcg_out_movi32 (s, ret, arg32);
> -    }
> -    else {
> -        if ((uint64_t) arg >> 32) {
> -            uint16_t h16 = arg >> 16;
> -            uint16_t l16 = arg;
> -
> -            tcg_out_movi32 (s, ret, arg >> 32);
> +    if (type == TCG_TYPE_I32 || arg == (int32_t)arg) {
> +        tcg_out_movi32(s, ret, arg);
> +    } else if (arg == (uint32_t)arg && !(arg & 0x8000)) {
> +        tcg_out32(s, ADDI | RT(ret) | RA(0) | (arg & 0xffff));
> +        tcg_out32(s, ORIS | RT(ret) | RA(ret) | ((arg >> 16) & 0xffff));
> +    } else {
> +        int32_t high = arg >> 32;
> +        tcg_out_movi32(s, ret, high);
> +        if (high) {
>              tcg_out_shli64(s, ret, ret, 32);
> -            if (h16) tcg_out32 (s, ORIS | RS (ret) | RA (ret) | h16);
> -            if (l16) tcg_out32 (s, ORI | RS (ret) | RA (ret) | l16);
>          }
> -        else {
> -            tcg_out_movi32 (s, ret, arg32);
> -            if (arg32 < 0)
> -                tcg_out_ext32u(s, ret, ret);
> +        if (arg & 0xffff0000) {
> +            tcg_out32(s, ORIS | RS(ret) | RA(ret) | ((arg >> 16) & 0xffff));
> +        }
> +        if (arg & 0xffff) {
> +            tcg_out32(s, ORI | RS(ret) | RA(ret) | (arg & 0xffff));
>          }
>      }
>  }

Reviewed-by: Aurelien Jarno <address@hidden>

-- 
Aurelien Jarno                          GPG: 1024D/F1BCDB73
address@hidden                 http://www.aurel32.net