[Bug middle-end/88784] Middle end is missing some optimizations about unsigned

[ffengqi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88784

--- Comment #7 from Qi Feng <ffengqi at gcc dot gnu.org> ---
I add some patterns in match.pd which handles the original 5 transformations.
But I don't the language used in match.pd well, the patterns I wrote are very
similar.

And I haven't found predicates for constant values other than zero (INT_MIN,
LONG_MIN, LLONG_MIN etc.).