src/share/classes/java/math/MutableBigInteger.java

rev 8880 : 8029501: BigInteger division algorithm selection heuristic is incorrect
Summary: Change Burnikel-Ziegler division heuristic to require that the dividend int-length exceed that of the divisor by a minimum amount.
Reviewed-by: TBD

*** 1146,1157 ****
      MutableBigInteger divide(MutableBigInteger b, MutableBigInteger quotient) {
          return divide(b,quotient,true);
      }
  
      MutableBigInteger divide(MutableBigInteger b, MutableBigInteger quotient, boolean needRemainder) {
!         if (intLen < BigInteger.BURNIKEL_ZIEGLER_THRESHOLD ||
!                 b.intLen < BigInteger.BURNIKEL_ZIEGLER_THRESHOLD) {
              return divideKnuth(b, quotient, needRemainder);
          } else {
              return divideAndRemainderBurnikelZiegler(b, quotient);
          }
      }
--- 1146,1157 ----
      MutableBigInteger divide(MutableBigInteger b, MutableBigInteger quotient) {
          return divide(b,quotient,true);
      }
  
      MutableBigInteger divide(MutableBigInteger b, MutableBigInteger quotient, boolean needRemainder) {
!         if (b.intLen < BigInteger.BURNIKEL_ZIEGLER_THRESHOLD ||
!                 intLen - b.intLen < BigInteger.BURNIKEL_ZIEGLER_OFFSET) {
              return divideKnuth(b, quotient, needRemainder);
          } else {
              return divideAndRemainderBurnikelZiegler(b, quotient);
          }
      }