On Thu, Dec 22, 2022 at 11:28:01AM +0000, Richard Biener wrote:
> On Thu, 22 Dec 2022, Jiufu Guo wrote:
> > To reduce risk, I'm just draft straightforward patches for
> > special cases currently, Like:
> > https://gcc.gnu.org/pipermail/gcc-patches/2022-December/608081.html
> > and this patch.
>
> Heh, yes - though I'm not fond of special-casing things. RTL
> expansion is already full of special cases :/
And many of those are not useful at all (would be done by later passes),
or are actively harmful. Not to mention that expand is currently one of
the most impregnable and undebuggable RTL passes.
But there are also many things done during expand that although they
should be done somewhat later, aren't actually done later at all
currently. So that needs fixing.
Maybe things should go via an intermediate step, where all the decisions
can be made, and then later we just have to translate the "low Gimple"
or "RTL-Gimple" ("Rimple"?) to RTL. A format that is looser in many
ways than either RTL or Gimple. A bit like Generic in that way.
Segher
