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From: Blue Swirl <blauwirbel@gmail.com>
Date: Mon, 28 Sep 2009 21:08:32 +0300
Message-ID: <f43fc5580909281108p1720e98dm421b858715da6392@mail.gmail.com>
Subject: Re: [Qemu-devel] [RFC] tcg: store constants without using registers
	when possible
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To: Aurelien Jarno <aurelien@aurel32.net>
Cc: qemu-devel@nongnu.org

On Mon, Sep 28, 2009 at 12:12 PM, Aurelien Jarno <aurelien@aurel32.net> wro=
te:
> Currently only implemented for x86/x86_64. It may also be implemented
> for targets that keep one register for TCG internal use.

Nice, but do you think the op will be used often?

> --- a/tcg/sparc/tcg-target.c
> +++ b/tcg/sparc/tcg-target.c
> @@ -392,6 +392,15 @@ static inline void tcg_out_st(TCGContext *s, TCGType=
 type, int arg,
> =C2=A0 =C2=A0 =C2=A0 =C2=A0 tcg_out_ldst(s, arg, arg1, arg2, STX);
> =C2=A0}
>
> +static inline int tcg_out_sti(TCGContext *s, TCGType type, tcg_target_lo=
ng val,
> + =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0 =
=C2=A0 =C2=A0 =C2=A0 =C2=A0 =C2=A0int arg1, tcg_target_long arg2)
> +{
> + =C2=A0 =C2=A0/* movl */
> + =C2=A0 =C2=A0tcg_out_modrm_offset(s, 0xc7, 0, arg1, arg2);
> + =C2=A0 =C2=A0tcg_out32(s, val);
> + =C2=A0 =C2=A0return 1;
> +}
> +

Sparc doesn't have store immediate ops, except for val =3D=3D 0 case:

static inline int tcg_out_sti(TCGContext *s, TCGType type, tcg_target_long =
val,
                              int arg1, tcg_target_long arg2)
{
  if (val !=3D 0) {
    return 0;
  }
  /* clr/clrx */
  tcg_out_st(s, type, TCG_REG_G0, arg1, arg2);
  return 1;
}