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Re: [tree-ssa] COND_EXPR lowering preview
- From: Zdenek Dvorak <rakdver at atrey dot karlin dot mff dot cuni dot cz>
- To: Jason Merrill <jason at redhat dot com>
- Cc: law at redhat dot com, Diego Novillo <dnovillo at redhat dot com>,"gcc-patches at gcc dot gnu dot org" <gcc-patches at gcc dot gnu dot org>,"gcc at gcc dot gnu dot org" <gcc at gcc dot gnu dot org>
- Date: Wed, 27 Aug 2003 22:49:19 +0200
- Subject: Re: [tree-ssa] COND_EXPR lowering preview
- References: <200308272021.h7RKLAl7009867@speedy.slc.redhat.com> <email@example.com>
> > >> We are going to be doing separate lowering pass with EH. We can
> > >> piggyback all the lowering code in there.
> > >>
> > >> The reason I tend to prefer this is more stylistic than anything else.
> > >> The only example I had in mind was code analysis. The purist in me
> > >> would like to have a clean separation between GIMPLE as an IL and the
> > >> lowering of GIMPLE to benefit our scalar optimizers. Since we are
> > >> already going to do a separate lowering pass, we could do it there.
> > >>
> > >> But, as I said before, I'm not that opposed to doing it in the
> > >> gimplifier. I don't have a strong technical reason now, so I'm happy
> > >> with what the majority thinks it's best.
> > >
> > >from "amount of work" point of view, I would slightly prefer a separate
> > >pass too. With cond_exprs I have somehow managed to place it into
> > >gimplification (although even this was more complicated than I thought),
> > >but for switch_expr lowering, this imho would be quite cumbersome.
> > Well, then let's make it separate lowering pass.
> For switches, OK, but there's already code to do COND_EXPR lowering in the
> gimplifier in order to handle && and || semantics. I really don't want
> two copies of that code floating around the compiler.
its 10 lines of code, so I don't think this is much of a problem.