"Scott Lipcon" <slipcon@xxxxxxxxx> writes:
> I'm trying to figure out how to get gcc to warn on a specific problem
> that we found in our source code. I've attached a simple test
> program that has a few places where floating point precision can
> potentially be lost or cause problems. Specifically:
> 1) Line 12, returns a double as a float without an explicit
> cast - loss of precision. Would like a warning here.
> 2) Line 19, same problem, but with fixed point - returns an int
> as a short, without a cast - loss of precision, would like a warning
> 3) Line 31, subtracts a float from a double (the constant is
> treated as a double, the variable is explicitly cast as a float. In
> this particular case, as can be seen in the printf on line 34, pi/2 -
> pi/2 does not equal zero. This seems like it might be harder to
> check for, but I'd love to see a warning here as well.
Manuel López-Ibáñez is working on warnings along these lines as part
of a Google Summer of Code project. See
http://gcc.gnu.org/wiki/Wcoercion
Ian
