Re: SIMPLE: A language-independent tree IR

[Alexandre Oliva <aoliva at redhat dot com>]

On Jan  6, 2002, Diego Novillo <dnovillo@redhat.com> wrote:

> On Sun, 06 Jan 2002, Alexandre Oliva wrote:
>> To me, this doesn't look too different from RTL.  The only important
>> difference appears to be the fact that arguments to function calls are
>> 
> RTL doesn't have:

> - Type information.
> - Array information.
> - Structured control-flow (particularly loops).
> - Pointer information.

IIRC, REGs and MEMs may now carry pointers to the DECLs they refer to,
so you get type and pointer information.  As for array information, we
may well come up with a new RTL code to indicate array indexing, or
just use PLUS for this purpose.  As for structured control-flow, the
machine-independent RTL may well have additional RTL codes to
represent it, and we can use SEQUENCES much more than we currently
do.

My point is that RTL is general enough that we don't need yet another
notation for a canonical 3-address representation.  RTL got that, we
just need to set the rules and conventions for it to behave however we
want.  If SIMPLE is what we're aiming at, let's figure out how to
represent it in RTL.  I don't see the point of creating yet another
set of data structures, management functions, etc.  It's a waste of
work.

-- 
Alexandre Oliva   Enjoy Guarana', see http://www.ic.unicamp.br/~oliva/
Red Hat GCC Developer                  aoliva@{cygnus.com, redhat.com}
CS PhD student at IC-Unicamp        oliva@{lsd.ic.unicamp.br, gnu.org}
Free Software Evangelist    *Please* write to mailing lists, not to me