[Bug c/108580] gcc treats shifts as signed operation, does wrong promotion

[postmaster at raasu dot org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108580

--- Comment #2 from postmaster at raasu dot org ---
If I try to shift to highest bit of signed type, the compiler will reject the
code and that is correct behaviour. The point here is that left-hand side of
the shift operation is by default same size as "int", as in 32 bits, which
means it can't be promoted to "int" again. 

This behaviour is same with gcc, clang and Visual C++, but Visual C++ correctly
gives warning that the code is ambiguous (exact message is "Arithmetic
overflow"), however it's also C++ compiler, which might validate the code with
C++ rules, not C.