[Bug middle-end/66872] fold a & ((1 << b) - 1) to a & ~(-1 << b)

[mpolacek at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66872

Marek Polacek <mpolacek at gcc dot gnu.org> changed:

           What    |Removed                     |Added
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                 CC|                            |mpolacek at gcc dot gnu.org

--- Comment #3 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
This ought to be easy to do in match.pd, but I'm not sure if this
transformation is beneficial for other architectures as well (it doesn't seem
to reduce the number of operations).