Re: RFC: objc_msgSend efficiency patch

[Dale Johannesen <dalej at apple dot com>]

On Feb 21, 2005, at 5:21 PM, Mark Mitchell wrote:

> Dale Johannesen wrote:
>
> > +           /* Postincrements in OBJ_TYPE_REF_OBJECT don't affect the
> > +              value of the OBJ_TYPE_REF, so force them to be emitted
> > +              during subexpression evaluation rather than after the
> > +              OBJ_TYPE_REF. This permits objc_msgSend calls in 
> > Objective
> > +              C to use direct rather than indirect calls when the
> > +              object expression has a postincrement.  */
> > +           r0 = gimplify_expr (&OBJ_TYPE_REF_OBJECT (*expr_p), 
> > pre_p, NULL,
> >                                 is_gimple_val, fb_rvalue);
> >             r1 = gimplify_expr (&OBJ_TYPE_REF_EXPR (*expr_p), pre_p, 
> > post_p,
> >                                 is_gimple_val, fb_rvalue);
>
> I think that change is unsafe.  I fixed a bug a while back where the 
> gimplifier was unable to insert the postincrement inline; in some 
> circumstances, I believe it will abort if you don't pass down post_p.

OK, thanks.  I can look into doing this in the ObjC-specific hook, 
unless you have
a better idea?