Function bi_reverse

extlibs/minizip/src/trees.c:1245–1257

=========================================================================== * Reverse the first len bits of a code, using straightforward code (a faster * method would use a table) * IN assertion: 1 <= len <= 15 */

(code, len)

 * IN assertion: 1 <= len <= 15
 */
local unsigned bi_reverse(code, len)
unsigned code; /* the value to invert */
int len; /* its bit length */
{
    register unsigned res = 0;
    do
    {
        res |= code & 1;
        code >>= 1 , res <<= 1;
    }
    while (--len > 0);
    return res >> 1;
}

/* ===========================================================================
 * Flush the bit buffer, keeping at most 7 bits in it.