On Fri, Jan 28, 2011 at 06:57:22PM +0100, Bruno Haible wrote: > Rich Felker wrote: > > Testing which of the three allowable signed integer > > representations is used is easy: compare ~(t)1 against and -(t)1 and > > -(t)2. > > Testing which of the three signed integer representations is in use > is not even needed: Your formula > ((((t) 1 << (sizeof (t) * CHAR_BIT - 2)) - 1) * 2 + 1) > yields the correct result in all three cases.
It yields the correct max. However, getting the min requires knowing whether min is -max or -max-1. This depends on which of the representations is used: min = ~(t)1 == -(t)2 ? -max-1 : -max; Rich
