On Tue, 3 May 2016, Richard Biener wrote:
On Tue, May 3, 2016 at 8:36 AM, Marc Glisse <marc.gli...@inria.fr> wrote:
This removes the duplication. I also removed the case (A&B)&(A&C) which is
handled by reassoc. And I need 2 NOP checks, for the case where @0 is a
constant (that couldn't happen before my patch because canonicalization
would put the constant as second operand).
Nicely spotted. Not sure we want to delay (A&B)&(A&C) until re-assoc. We have
many patterns that reassoc would also catch, like (A + CST) + CST or (A + B)- A,
albeit reassoc only handles the unsigned cases.
(A&B)&A seems simple enough for match.pd, I thought (A&B)&(A&C) was
starting to be a bit specialized. I could easily add it back (making it
work with | at the same time), but then I am not convinced A&(B&C) is the
best output. If A&B or A&C have several uses, then (A&B)&C or B&(A&C) seem
preferable (and we would still have a transformation for (A&cst1)&cst2 so
we wouldn't lose in the case where B and C are constants). We may still
end up having to add some :s to the transformation I just touched.
--
Marc Glisse
