https://gcc.gnu.org/bugzilla/show_bug.cgi?id=115551
--- Comment #3 from Tobias Burnus <burnus at gcc dot gnu.org> --- As we want to have a >= 0, I tried to convey it differently for the example in comment 0: (a) __attribute__((assume(ch >= 0))); (b) 'unsigned ch' (instead of 'int ch') but it didn't help. Thus, it looks as if it could be implemented for: c1 << (a + c2) if (a >= 0 and c2 >= 0) doing then the conversion (c1 << c2) << a Whether Ranger handles abs(c2) > c3 >= 0 → a >= 0 for 'c1 << (a*c2 + c3)', I don't know, but the variant above with unsigned and 'assume(a >= 0)' should be implementable and seems to make sense.
