consistent unspecified pointer comparison

[Richard Biener]

> Am 27.06.2024 um 19:04 schrieb Jason Merrill via Gcc <gcc@gcc.gnu.org>:
> 
> https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2024/p2434r1.html
> proposes to require that repeated unspecified comparisons be
> self-consistent, which does not match current behavior in either GCC
> or Clang.  The argument is that the current allowance to be
> inconsistent is user-unfriendly and does not enable significant
> optimizations.  Any feedback about this?

Can you give an example of an unspecified comparison?  I think the only way to do what the paper wants is for the implementation to make the comparison specified (without the need to document it).  Is the self-consistency required only within some specified scope (a single expression?) or even across TUs (which might be compiled by different compilers or compiler versions)?

So my feedback would be to make the comparison well-defined.

I’m still curious about which ones are unspecified now.

Richard 

> 
> Jason
>