[Bug tree-optimization/91227] pointer relational expression not folded but equivalent inequality is

[joseph at codesourcery dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91227

--- Comment #18 from joseph at codesourcery dot com <joseph at codesourcery dot com> ---
I don't expect people to do such comparisons with addresses of local 
variables directly.  It is plausible that they have a memmove-like 
function, and once it gets inlined the compiler can see that, at a 
particular call site, it's doing such comparisons involving addresses of 
local variables.  The question then is whether this might result in 
problems if e.g. the comparisons say two arrays are both before and after 
each other and the memmove-like function isn't prepared for that.  And, 
then, whether we say that's OK and such a function needs to cast to 
uintptr_t as the way to make something that's valid in 
C-with-ABI-boundaries into something that works in GNU C in the presence 
of (possibly LTO) inlining.