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Re: From SSA back to GIMPLE.
- From: "J.C. Pizarro" <jcpiza at gmail dot com>
- To: "Jose ." <kasty dot jose at gmail dot com>, gcc at gcc dot gnu dot org, "Diego Novillo" <dnovillo at redhat dot com>
- Date: Mon, 22 Oct 2007 15:58:55 +0200
- Subject: Re: From SSA back to GIMPLE.
Jose wrote:
> Hi all,
>
> this is my first post in this mailing list. I'm trying to understand
> GCC 4 as part of my research, but I'm finding questions which are
> difficult to answer just with online documentation.
>
> I understand that the whole process of compiling a C file involves
> GENERIC->GIMPLE->SSA->GIMPLE->RTL
>
> If I'm not wrong, GCC currently cannot go from SSA to RTL directly.
> What I don't understand is what happens with all versions of the same
> variable when doing the SSA->GIMPLE step. Are they mixed into a single
> variable declaration? Are they treated as separate variables and
> handled later by the register allocator?
>
> Thanks in advance.
> Jose.
Is not it easy to write 3 stages GENERIC->GIMPLE->RTL instead of 5 stages?
Is meaningful the optimization of the complex bi-transformation
GIMPLE->SSA->GIMPLE?
Is more powerful GENERIC->GIMPLE->RTL + "trial-and-error" local optimization?
Sincerely, J.C. Pizarro