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#include "os.h"
#include <mp.h>
#include "dat.h"
// res = s != 0 ? b1 : b2
void
mpsel(int s, mpint *b1, mpint *b2, mpint *res)
{
mpdigit d;
int n, m, i;
res->flags |= (b1->flags | b2->flags) & MPtimesafe;
if((res->flags & MPtimesafe) == 0){
mpassign(s ? b1 : b2, res);
return;
}
res->flags &= ~MPnorm;
n = b1->top;
m = b2->top;
mpbits(res, Dbits*(n >= m ? n : m));
res->top = n >= m ? n : m;
s = (-s^s|s)>>(sizeof(s)*8-1);
res->sign = (b1->sign & s) | (b2->sign & ~s);
d = -((mpdigit)s & 1);
i = 0;
while(i < n && i < m){
res->p[i] = (b1->p[i] & d) | (b2->p[i] & ~d);
i++;
}
while(i < n){
res->p[i] = b1->p[i] & d;
i++;
}
while(i < m){
res->p[i] = b2->p[i] & ~d;
i++;
}
}
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