Re: [Qemu-devel] [PATCH] m68k: implement move to/from usp register instruction

[Greg Ungerer]

Hi Richard,

On 14/09/12 03:34, Richard Henderson wrote:
> On 09/12/2012 11:33 PM, address@hidden wrote:
> > +uint32_t HELPER(move_from_usp)(CPUM68KState * env)
> > +{
> > +    return env->sp[M68K_USP];
> > +}
>
> You don't need helpers for these.
>
> >   DISAS_INSN(move_from_usp)
> >   {
> > +    TCGv reg;
> >       if (IS_USER(s)) {
> >           gen_exception(s, s->pc - 2, EXCP_PRIVILEGE);
> >           return;
> >       }
> > -    /* TODO: Implement USP.  */
> > -    gen_exception(s, s->pc - 2, EXCP_ILLEGAL);
> > +    reg = AREG(insn, 0);
> > +    gen_helper_move_from_usp(reg, cpu_env);
>
>    tcg_gen_ld_i32(AREG(insn, 0), offsetof(CPUM68KState, sp[M68K_USP]));
>
> >   DISAS_INSN(move_to_usp)
> >   {
> > +    TCGv reg;
> >       if (IS_USER(s)) {
> >           gen_exception(s, s->pc - 2, EXCP_PRIVILEGE);
> >           return;
> >       }
> > -    /* TODO: Implement USP.  */
> > -    gen_exception(s, s->pc - 2, EXCP_ILLEGAL);
> > +    reg = AREG(insn, 0);
> > +    gen_helper_move_to_usp(cpu_env, reg);
>
>    tcg_gen_st_i32(AREG(insn, 0), offsetof(CPUM68KState, sp[M68K_USP]));

That looks cleaner, thanks. I'll send a revised patch.

Regards
Greg


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Greg Ungerer  --  Principal Engineer        EMAIL:     address@hidden
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