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/*% clang -g -Wall -o # %
*
* This is a test program for the slot
* routine in isel.c, it's a tricky beast
* so when you modify it you can use this
* test program to debug your changes.
*
* Please make sure it stays in sync.
*/
#include <assert.h>
#include <stdlib.h>
#include <stdio.h>
#include <time.h>
#define VARL 1
enum { N = 3 };
static int sa[N] = {0, 0, 2};
static int
slot(int sz, int al)
{
int j, k, s, l, a, ret;
a = 1 << al;
l = sz;
if (l > a) {
/* for large slots, we just
* tack them on the next max
* alignment slot available
* todo, could sophisticate
*/
l = (l + a-1) & ~(a-1);
s = sa[N-1] + l;
ret = s;
for (j=0, k=1; j<N; j++, k*=2) {
l = (l + k-1) & ~(k-1);
sa[j] = sa[N-1] + l;
}
} else {
j = al;
s = sa[j] + a;
ret = s;
Shift:
if (j < N-1 && s < sa[j+1])
/* ........-----------...
* ^ ^ ^
* sa[j] sa[j]+a sa[j+1]
*
* we have to skip to the
* next large whole
*/
s = sa[j+1];
for (k=0; k<=j; k++)
/* move all smaller holes
* that we contain with us
*/
if (sa[k] == sa[j])
sa[k] = s;
if (j < N-1 && s > sa[j+1]) {
/* we were in a bigger hole,
* it needs to shift further
*/
s = sa[++j] + (a *= 2);
goto Shift;
}
}
return ret;
}
enum { S = 300 };
int
main(int ac, char *av[])
{
char stk[S] = {0}, buf[4] = {0};
unsigned seed;
int i, a, l, s, itr;
int ret;
FILE *rnd;
if (ac < 2) {
rnd = fopen("/dev/urandom", "r");
fread(buf, 4, 1, rnd);
seed = *(unsigned *)buf;
printf("seed: %u", seed);
fclose(rnd);
} else
seed = atol(av[1]);
srand(seed);
for (itr=1;;itr++) {
if ((itr-1) % 4 == 0)
printf("\n");
do
a = rand() % 4;
while (a >= N);
if ((float)rand()/RAND_MAX < 0.1 && VARL) {
l = rand() % (S/20);
printf("[(%02d) %02d %d] ", itr, l, a);
} else {
l = 1 << a;
printf("[(%02d) xx %d] ", itr, a);
}
s = slot(l, a);
if (s > S)
break;
if ((s+2) % (1 << a) != 0) {
printf("... FAIL (%d align)\n", s);
ret = 1;
goto end;
}
for (i=0; i<l; i++) {
s--;
assert(s >= 0);
if (stk[s]) {
printf("... FAIL (%d)\n", s);
ret = 1;
goto end;
}
stk[s] = itr;
}
}
for (s=0, i=0; i<S; i++)
if (!stk[i])
s++;
printf("... OK (%d)\n", s);
ret = 0;
end:
printf("\n");
for (i=0; i<S; i++)
printf("%02d ", stk[i]);
printf("\n\n");
for (i=0; i<N; i++)
printf("sa[%d] = %d\n", i, sa[i]);
exit(ret);
}
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