Hello, This is a test-only change.
Issue: https://bugs.openjdk.java.net/browse/JDK-8058505 Webrev: http://cr.openjdk.java.net/~bpb/8058505/webrev.00/ I verified that the updated version passes (as mentioned below) and in fact exercises the B-Z division branch of the library code. Thanks, Brian On Sep 15, 2014, at 7:17 AM, Robert Gibson <robbiexgib...@yahoo.com> wrote: > Here is a patch to fix the test bug mentioned previously. The > Burnikel-Ziegler division code is now exercised, and you'll be glad to know > that the tests still pass! > Robert > > --- BigIntegerTest.java 2014-09-15 15:55:47.632012000 +0200 > +++ BigIntegerTestPatched.java 2014-09-15 16:07:53.363563000 +0200 > @@ -71,6 +71,7 @@ > static final int BITS_TOOM_COOK_SQUARE = 6912; > static final int BITS_SCHOENHAGE_BASE = 640; > static final int BITS_BURNIKEL_ZIEGLER = 2560; > + static final int BITS_BURNIKEL_ZIEGLER_OFFSET = 1280; > static final int ORDER_SMALL = 60; > static final int ORDER_MEDIUM = 100; > @@ -288,19 +289,19 @@ > * where {@code abs(u) > abs(v)} and {@code a > b && b > 0}, then if > * {@code w/z = q1*z + r1} and {@code u/v = q2*v + r2}, then > * {@code q1 = q2*pow(2,a-b)} and {@code r1 = r2*pow(2,b)}. The test > - * ensures that {@code v} is just under the B-Z threshold and that > {@code w} > - * and {@code z} are both over the threshold. This implies that {@code > u/v} > - * uses the standard division algorithm and {@code w/z} uses the B-Z > - * algorithm. The results of the two algorithms are then compared using > the > - * observation described in the foregoing and if they are not equal a > - * failure is logged. > + * ensures that {@code v} is just under the B-Z threshold, that {@code > z} is > + * over the threshold and {@code w} is much larger than {@code z}. This > + * implies that {@code u/v} uses the standard division algorithm and > + * {@code w/z} uses the B-Z algorithm. The results of the two algorithms > + * are then compared using the observation described in the foregoing and > + * if they are not equal a failure is logged. > */ > public static void divideLarge() { > int failCount = 0; > - BigInteger base = BigInteger.ONE.shiftLeft(BITS_BURNIKEL_ZIEGLER - > 33); > + BigInteger base = BigInteger.ONE.shiftLeft(BITS_BURNIKEL_ZIEGLER + > BITS_BURNIKEL_ZIEGLER_OFFSET - 33); > for (int i=0; i<SIZE; i++) { > - BigInteger addend = new BigInteger(BITS_BURNIKEL_ZIEGLER - 34, > rnd); > + BigInteger addend = new BigInteger(BITS_BURNIKEL_ZIEGLER + > BITS_BURNIKEL_ZIEGLER_OFFSET - 34, rnd); > BigInteger v = base.add(addend); > BigInteger u = v.multiply(BigInteger.valueOf(2 + > rnd.nextInt(Short.MAX_VALUE - 1))); > @@ -312,14 +313,14 @@ > v = v.negate(); > } > - int a = 17 + rnd.nextInt(16); > + int a = BITS_BURNIKEL_ZIEGLER_OFFSET + rnd.nextInt(16); > int b = 1 + rnd.nextInt(16); > - BigInteger w = u.multiply(BigInteger.valueOf(1L << a)); > - BigInteger z = v.multiply(BigInteger.valueOf(1L << b)); > + BigInteger w = u.multiply(BigInteger.ONE.shiftLeft(a)); > + BigInteger z = v.multiply(BigInteger.ONE.shiftLeft(b)); > BigInteger[] divideResult = u.divideAndRemainder(v); > - divideResult[0] = divideResult[0].multiply(BigInteger.valueOf(1L > << (a - b))); > - divideResult[1] = divideResult[1].multiply(BigInteger.valueOf(1L > << b)); > + divideResult[0] = > divideResult[0].multiply(BigInteger.ONE.shiftLeft(a - b)); > + divideResult[1] = > divideResult[1].multiply(BigInteger.ONE.shiftLeft(b)); > BigInteger[] bzResult = w.divideAndRemainder(z); > if (divideResult[0].compareTo(bzResult[0]) != 0 ||
