https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65752
--- Comment #42 from Alexander Cherepanov <ch3root at openwall dot com> --- On 2015-11-16 00:48, pinskia at gcc dot gnu.org wrote: > https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65752 > > --- Comment #41 from Andrew Pinski <pinskia at gcc dot gnu.org> --- > (In reply to Alexander Cherepanov from comment #40) >> Ok, this program: >> >> #include <stdint.h> >> #include <stdio.h> >> >> int main() { >> int y, x = 0; >> int *volatile v = &x; >> int *xp = v; >> int *i = &y + 1; >> >> if (xp != i) { >> printf("hello\n"); >> xp = i; >> } >> >> printf("%d\n", xp == &x); >> } Small correction: it prints 0 and doesn't print "hello" even though it should print 1 without "hello" or an unspecified value with "hello". > Still undefined as &x and &y + 1 are not comparable. They cannot be compared with the relational operators ("<" etc.) but you can compare any pointers with the equality operators ("==" and "!=").
