/* Constant time version. */
static uint32_t single_sample_ct(uint64_t *in) {
uint32_t index = 0, i;
for (i = 0; i < 52; i++) {
index = ct_select_u64(index, i, cmplt_ct(in, rlwe_table[i]));
}
return index;
}
/* Constant time version. */
static uint32_t single_sample_ct(uint64_t *in) {
uint32_t index = 0, i;
for (i = 0; i < 52; i++) {
uint32_t mask1, mask2;
mask1 = cmplt_ct(in, rlwe_table[i]);
mask1 = (uint32_t) (0 - (int32_t) mask1);
mask2 = (~mask1);
index = ((index & mask1) | (i & mask2));
}
return index;
}
static uint32_t single_sample(uint64_t *in) {
uint32_t lower_index = 0, this_index = 32, upper_index = 64;
int i;
for (i = 0; i < 6; i++) {
if (cmplt_ct(in, rlwe_table[this_index])) {
upper_index = this_index;
} else {
lower_index = this_index;
}
this_index = (lower_index + upper_index) / 2;
}
return lower_index;
}
