signed is undefined and has been since 1992 (in GCC)

[Michael Veksler]

Andrew Pinski wrote on 28/06/2005 07:08:33:

> The first change in GCC which changed signed overflow/wrapping to be
> undefined
> was added back in 1992 in loop.c.  The next change was in 1999 with the
> addition of simplify-rtx.c.  Why are we talking about this now, instead
> of back
> when they were added?  (note both of these changes were before fwrapv
> can into
> play).
>
I don't mind MAX_INT+1 being undefined by gcc. I object to drawing from
"undefined" to conclude that is_modulo should be true. This does not
make a practical sense. Drawing conclusions from "undefined" can yield
absurd results.