88 lines
2.2 KiB
C
88 lines
2.2 KiB
C
|
#include "sort.h"
|
||
|
|
|
||
|
|
/*
|
||
|
|
Constant-time uint32_t sorting by Daniel J. Bernstein
|
||
|
|
Source: https://sorting.cr.yp.to
|
||
|
|
*/
|
||
|
|
|
||
|
|
static void int32_sort(int32 *x, size_t n) {
|
||
|
|
size_t top, p, q, r, i, j;
|
||
|
|
|
||
|
|
if (n < 2) {
|
||
|
|
return;
|
||
|
|
}
|
||
|
|
top = 1;
|
||
|
|
while (top < n - top) {
|
||
|
|
top += top;
|
||
|
|
}
|
||
|
|
|
||
|
|
for (p = top; p >= 1; p >>= 1) {
|
||
|
|
i = 0;
|
||
|
|
while (i + 2 * p <= n) {
|
||
|
|
for (j = i; j < i + p; ++j) {
|
||
|
|
int32_MINMAX(x[j], x[j + p]);
|
||
|
|
}
|
||
|
|
i += 2 * p;
|
||
|
|
}
|
||
|
|
for (j = i; j < n - p; ++j) {
|
||
|
|
int32_MINMAX(x[j], x[j + p]);
|
||
|
|
}
|
||
|
|
|
||
|
|
i = 0;
|
||
|
|
j = 0;
|
||
|
|
for (q = top; q > p; q >>= 1) {
|
||
|
|
if (j != i) {
|
||
|
|
for (;;) {
|
||
|
|
if (j == n - q) {
|
||
|
|
goto done;
|
||
|
|
}
|
||
|
|
int32 a = x[j + p];
|
||
|
|
for (r = q; r > p; r >>= 1) {
|
||
|
|
int32_MINMAX(a, x[j + r]);
|
||
|
|
}
|
||
|
|
x[j + p] = a;
|
||
|
|
++j;
|
||
|
|
if (j == i + p) {
|
||
|
|
i += 2 * p;
|
||
|
|
break;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
while (i + p <= n - q) {
|
||
|
|
for (j = i; j < i + p; ++j) {
|
||
|
|
int32 a = x[j + p];
|
||
|
|
for (r = q; r > p; r >>= 1) {
|
||
|
|
int32_MINMAX(a, x[j + r]);
|
||
|
|
}
|
||
|
|
x[j + p] = a;
|
||
|
|
}
|
||
|
|
i += 2 * p;
|
||
|
|
}
|
||
|
|
/* now i + p > n - q */
|
||
|
|
j = i;
|
||
|
|
while (j < n - q) {
|
||
|
|
int32 a = x[j + p];
|
||
|
|
for (r = q; r > p; r >>= 1) {
|
||
|
|
int32_MINMAX(a, x[j + r]);
|
||
|
|
}
|
||
|
|
x[j + p] = a;
|
||
|
|
++j;
|
||
|
|
}
|
||
|
|
done:
|
||
|
|
;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
/* can save time by integrating xor loops with int32_sort */
|
||
|
|
void PQCLEAN_LEDAKEMLT32_LEAKTIME_uint32_sort(uint32_t *x, size_t n) {
|
||
|
|
size_t j;
|
||
|
|
for (j = 0; j < n; ++j) {
|
||
|
|
x[j] ^= 0x80000000;
|
||
|
|
}
|
||
|
|
int32_sort((int32_t *) x, n);
|
||
|
|
for (j = 0; j < n; ++j) {
|
||
|
|
x[j] ^= 0x80000000;
|
||
|
|
}
|
||
|
|
}
|