mirror of
https://github.com/0intro/conterm
synced 2024-11-22 05:41:28 +03:00
41 lines
695 B
C
41 lines
695 B
C
#include "os.h"
|
|
#include <mp.h>
|
|
#include "dat.h"
|
|
|
|
// res = b >> shift
|
|
void
|
|
mpright(mpint *b, int shift, mpint *res)
|
|
{
|
|
int d, l, r, i;
|
|
mpdigit this, last;
|
|
|
|
// a negative right shift is a left shift
|
|
if(shift < 0){
|
|
mpleft(b, -shift, res);
|
|
return;
|
|
}
|
|
|
|
if(res != b)
|
|
mpbits(res, b->top*Dbits - shift);
|
|
d = shift/Dbits;
|
|
r = shift - d*Dbits;
|
|
l = Dbits - r;
|
|
|
|
// special case digit shifts
|
|
if(r == 0){
|
|
for(i = 0; i < b->top-d; i++)
|
|
res->p[i] = b->p[i+d];
|
|
} else {
|
|
last = b->p[d];
|
|
for(i = 0; i < b->top-d-1; i++){
|
|
this = b->p[i+d+1];
|
|
res->p[i] = (this<<l) | (last>>r);
|
|
last = this;
|
|
}
|
|
res->p[i++] = last>>r;
|
|
}
|
|
while(i > 0 && res->p[i-1] == 0)
|
|
i--;
|
|
res->top = i;
|
|
}
|