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optimisation internals question
- To: egcs at cygnus dot com (egcs mailing list), gcc2 at cygnus dot com (gcc mailing list)
- Subject: optimisation internals question
- From: "Philippe De Muyter" <phdm at macqel dot be>
- Date: Fri, 17 Jul 1998 19:24:47 +0200 (CEST)
I have some some optimisations (about long long e.g) that I would like to
add to gcc. The problem is that I cannot convince gcc to use them.
I have put my optimisations in simplify_rtx, but although my rewrite rules
are executed and a new rtx is returned by simplify_rtx, it is not choosen
because recog_for_combine fails for it. That is normal because
the new rtx would map to two instruction patterns (or more), not
on one. Is there a way in simplify_rtx to tell the combiner where
are the split-points of the new rtx, or should I move those optimisations
to somewhere else ?
Philippe De Muyter (phdm@macqel.be)