https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91946
--- Comment #8 from Tim Ruehsen ---
Here is a good blog post about pointer overflow:
https://blog.regehr.org/archives/1395
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91946
--- Comment #7 from Tim Ruehsen ---
Thanks for the explanations :-)
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91946
--- Comment #6 from Richard Biener ---
You can use -fwrapv-pointer to make pointer-wrapping defined.
In C you are only allowed to use relational compares on pointers to the same
object. On x86-linux there is no valid object at address zero
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91946
--- Comment #5 from Andrew Pinski ---
I mean comparisons which are not equals or not equals outside of array bounds
is undefined.
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91946
--- Comment #4 from Andrew Pinski ---
Also this was an a broken ABI mistake a long time ago. Also comparing for non
equality outside an array bounds (besides one past the end) is also undefined
behavior. Undefined behavior does NOT need to be
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91946
--- Comment #3 from Andrew Pinski ---
Sorry i mean ptrdiff_t .
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91946
--- Comment #2 from Tim Ruehsen ---
Is ssize_t C99 ?
Could you point to the specs so that any reader can verify that ?
And by UB you mean, gcc sometimes gives 0 and sometimes 1 ? Even if it's UB,
the behavior should be consistent.
Since this
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=91946
Andrew Pinski changed:
What|Removed |Added
Status|UNCONFIRMED |RESOLVED
Component|c
