https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86889
--- Comment #2 from Ilya Leoshkevich <iii at linux dot ibm.com> ---
C-Reduced version:
struct a {
long b[128 / (8 * 8)];
};
int c;
void d() {
a *e;
long f;
int g = 1;
for (; g >= 0; g--) {
f = e->b[g];
if (f)
goto h;
}
__builtin_unreachable();
h:
c = g;
}
Repro:
$ PATH=build/prev-gcc:$PATH xg++ -c -O2 -Warray-bounds bitmap.E.c
bitmap.E.c: In function ‘void d()’:
bitmap.E.c:10:15: warning: array subscript -1 is below array bounds of ‘long
int [2]’ [-Warray-bounds]
f = e->b[g];
~~~~~~^
