https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110588
Roger Sayle <roger at nextmovesoftware dot com> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |roger at nextmovesoftware dot
com
Status|UNCONFIRMED |ASSIGNED
Ever confirmed|0 |1
Assignee|unassigned at gcc dot gnu.org |roger at
nextmovesoftware dot com
Last reconfirmed| |2023-07-08
--- Comment #1 from Roger Sayle <roger at nextmovesoftware dot com> ---
Thanks Andrew. I have a patch (a define_split in i386.md) that's currently
bootstrapping and regression testing. But perhaps this should also be fixed at
the tree-level by match.pd canonicalizing ((T)(x & C)) ^ C to (T)((~x) & C)
when T is not wider than X and X is not wider than WORD_MODE. It's tricky to
compare the costs of integer operations in different precisions, but WORD_MODE
(and int) operations are (typically) always cheap (and I believe unary
operations are preferred over binary operations (with immediate constants)).
