[Bug tree-optimization/113662] [13/14/15 Regression] Wrong code for std::sort with fancy pointer since r13-6945-g429a7a88438cc8

[pinskia at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113662

--- Comment #10 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
(In reply to Andrew Pinski from comment #9)
> There is something off by this offset_ptr.

I am almost want to say this code is undefined; it is at least questionable.

>From the looks of it, it does:

offset = (intptr_t)this - (intptr_t)array;

then array = offset + (intptr_t)this;

I am still trying to figure out if that is valid. I have not idea why boost
even has this kind of thing.