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When to ingore signed vs. unsigned comparison?
- From: Richard Guenther <rguenth at tat dot physik dot uni-tuebingen dot de>
- To: gcc at gcc dot gnu dot org
- Date: Tue, 8 Feb 2005 12:20:16 +0100 (CET)
- Subject: When to ingore signed vs. unsigned comparison?
In tackling the missed folding of &a[2]-1 to &a[1], I'm
getting unsigned indices instead of signed ones. For
further allowing &a[1] == &a[1] to be folded, I need a way
to say if I can ignore that 1 (lhs) is unsinged and 1 (rhs)
is signed.
I.e. we don't fold &a[1] == &a[1U] at the moment - how to fix
this? I tried using may_negate_without_overflow_p, but that
does another thing. Is there some utility function that would
help me doing this? Any hints?
Thanks,
Richard.
--
Richard Guenther <richard dot guenther at uni-tuebingen dot de>
WWW: http://www.tat.physik.uni-tuebingen.de/~rguenth/