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

[Robert Dewar]

Andrew Pinski wrote:

> No it is not. It was when it was designed yes but since the C standard has
> come out and the aliasing rules really show that it is not a high level
> assembler language any more.

Even when it was designed there was more abstraction than you think (e.g.
cannot convert *char value to *int, cannot compare addresses in different
allocated objects).