[Bug c/67999] Wrong optimization of pointer comparisons

[ch3root at openwall dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67999

--- Comment #4 from Alexander Cherepanov <ch3root at openwall dot com> ---
Interesting. In particular, this means that the warning "Argument 'size' of
function malloc has a fishy (possibly negative) value" from valgrind is a
serious thing. Is this gcc limitation documented somewhere? Is there a better
reference than this bug?

Am I right that the C standards do not allow for such a limitation (and hence
this should not be reported to glibc as a bug) and gcc is not
standards-compliant in this regard? Or I'm missing something?