Function test_nonzero_timingsafe

server/util.c:3820–3833

 */
#if __has_attribute(always_inline)
__attribute__((always_inline))
#endif
static APR_INLINE int test_nonzero_timingsafe(apr_uint32_t x)
{
    x |= -x; /* sets the most significant bit unless x == 0 */

    /* shift bit 31 (MSB) to bit 0 */
    x >>= 32-6;      /* keep 6 bits */
    x += optblocker; /* lose the optimizer */
    x >>= 5;         /* keep the (original) MSB only */

    /* x is now 0 or 1 */
    return x & INT_MAX;
}

AP_DECLARE(int) ap_memeq_timingsafe(const void *buf1, const void *buf2,
                                     apr_size_t n)