flagging unsigned subtraction assigned to bigger signed number?

[Derek Fawcus]

On Wednesday, 21 May 2025 at 19:19:37 UTC, Derek Fawcus wrote:
> It has been a long time since I last used it, but I vaguely 
> recall that
> sign preserving was what K&R specified, and what the Bell Labs 
> / AT&T compilers did.
>
> Hence this was actually a change by the ANSI committee.
>
> (Maybe the then existing value preserving compilers did so for 
> a good reason)

Yup: https://home.nvg.org/~skars/programming/C_Rationale.pdf

(page 40 & 41)

"After much discussion, the Committee decided in favor of value 
preserving rules, despite the fact that the UNIX C compilers had 
evolved in the direction of unsigned preserving."