bridge/class-master/depend/pari/src/basemath/ifactor1.c
/* Tuning parameter:  for input up to 64 bits long, we must not spend more
 * than a very short time, for fear of slowing things down on average.
 * With the current tuning formula, increase our efforts somewhat at 49 bit
 * input (an extra round for each bit at first),  and go up more and more
 * rapidly after we pass 80 bits.-- Changed this to adjust for the presence of
 * squfof, which will finish input up to 59 bits quickly. */
Tuning parameter:  for input up to 64 bits long, we must not spend more
than a very short time, for fear of slowing things down on average.
With the current tuning formula, increase our efforts somewhat at 49 bit
input (an extra round for each bit at first),  and go up more and more
rapidly after we pass 80 bits.-- Changed this to adjust for the presence of
squfof, which will finish input up to 59 bits quickly.
Tuning parameter : for input up to 64 bits long we must not spend more than a very short time for fear of slowing things down on average . With the current tuning formula increase our efforts somewhat at 49 bit input ( an extra round for each bit at first ) and go up more and more rapidly after we pass 80 bits . -- Changed this to adjust for the presence of squfof which will finish input up to 59 bits quickly .
static GEN
pollardbrent(GEN n)
{
  const long tune_pb_min = 14; 
  long c0, size = expi(n) + 1;
  if (size <= 28)
    c0 = 32;
  else if (size <= 42)
    c0 = tune_pb_min;
  else if (size <= 59) 
    c0 = tune_pb_min + ((size - 42)<<1);
  else if (size <= 72)
    c0 = tune_pb_min + size - 24;
  else if (size <= 301)
    c0 = tune_pb_min + size - 60 +
      ((size-73)>>1)*((size-70)>>3)*((size-56)>>4);
  else
    c0 = 49152; 
  return pollardbrent_i(n, size, c0, 0);
}
static GEN pollardbrent ( GEN n ) { const long tune_pb_min = 14 ; long c0 , size = expi ( n ) + 1 ; if ( size <= 28 ) c0 = 32 ; else if ( size <= 42 ) c0 = tune_pb_min ; else if ( size <= 59 ) c0 = tune_pb_min + ( ( size - 42 ) << 1 ) ; else if ( size <= 72 ) c0 = tune_pb_min + size - 24 ; else if ( size <= 301 ) c0 = tune_pb_min + size - 60 + ( ( size - 73 ) >> 1 ) * ( ( size - 70 ) >> 3 ) * ( ( size - 56 ) >> 4 ) ; else c0 = 49152 ; return pollardbrent_i ( n , size , c0 , 0 ) ; }
Tuning parameter:  for input up to 64 bits long, we must not spend more
 than a very short time, for fear of slowing things down on average.
Tuning parameter : for input up to 64 bits long we must not spend more than a very short time for fear of slowing things down on average .
/* even 15 seems too much. */ /* amounts very nearly to 'insist'. Now that we have squfof(), we
             * don't insist any more when input is 2^29 ... 2^32 */ /* match squfof() cutoff point */ /* nonlinear increase in effort, kicking in around 80 bits */ /* 301 gives 48121 + tune_pb_min */ /* ECM is faster when it'd take longer */