On Wed, Dec 07, 2016 at 03:33:42PM +0100, Luc Van Oostenryck wrote: > But what is really done currently is something like: > x = x + (typeof(x)) a; > In other words, the left-hand side is casted to the same type as the > rhs and the operation is always done with this type, neglecting the > usual conversions and thus forcing the operation to always be done > with the rhs type, here 'int' instead of 'long'. Addition is a bad example, actually - your variant (promotions + operaton + cast down to the first argument due to assignment) will yield the same value. It's division where the real trouble happens - unsigned n1 = 1, n2 = 1; long v = -1; n1 /= v; n2 /= (unsigned)v; should yield n1 == ~0U, n2 == 0. And yes, the current logics in sparse does not distinguish between those. So ACK on the fix, but you want a better testcase. -- To unsubscribe from this list: send the line "unsubscribe linux-sparse" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
