> So what purpose did the Standard allowing that actually achieve?
I believe the situation was that there were C implementations for DSPs (32-bit-addressable only) and IBM mainframes (36-bit addressable only), and when ANSI/ISO C was established, they naturally wanted their implementations to be able to conform to that new standard. So the standard was made flexible enough to accommodate such implementations.
Similarly why signed overflow is undefined behavior. There were existing implementations that trapped (CPU interrupt) on signed overflow.
I might have gotten the details wrong, but that's what I remember from reading comp.std.c (Usenet) in the 90s.
I believe the situation was that there were C implementations for DSPs (32-bit-addressable only) and IBM mainframes (36-bit addressable only), and when ANSI/ISO C was established, they naturally wanted their implementations to be able to conform to that new standard. So the standard was made flexible enough to accommodate such implementations.
Similarly why signed overflow is undefined behavior. There were existing implementations that trapped (CPU interrupt) on signed overflow.
I might have gotten the details wrong, but that's what I remember from reading comp.std.c (Usenet) in the 90s.