Looks good Brian; thanks,
-Joe
On 12/10/2015 2:32 PM, Brian Burkhalter wrote:
A new version is here:
http://cr.openjdk.java.net/~bpb/8032027/webrev.05/
<http://cr.openjdk.java.net/%7Ebpb/8032027/webrev.05/>
I changed the test to verify these values:
Stream.Builder<BigInteger> sb = Stream.builder();
int maxExponent = Double.MAX_EXPONENT + 1;
for (int i = 1; i <= maxExponent; i++) {
BigInteger p2 = BigInteger.ONE.shiftLeft(i);
sb.add(p2.subtract(BigInteger.ONE));
sb.add(p2);
sb.add(p2.add(BigInteger.ONE));
}
sb.add((new BigDecimal(Double.MAX_VALUE)).toBigInteger());
sb.add((new
BigDecimal(Double.MAX_VALUE)).toBigInteger().add(BigInteger.ONE));
report("squareRoot for 2^N and 2^N - 1, 1 <= N <= Double.MAX_EXPONENT",
sb.build().collect(Collectors.summingInt(f)));
At line 1892 of the current version of MutableBigInteger I changed "if
(bitLength() < 63)" to "if (bitLength() <= 63)". I realized that in
that case the entire calculation might as well be done in longs so I
changed it accordingly. The modified test passes with this new revision.
Thanks,
Brian
On Dec 9, 2015, at 6:11 PM, Joseph D. Darcy <joe.da...@oracle.com
<mailto:joe.da...@oracle.com>> wrote:
New version looks good.
One more case to try: start with a BigInteger that would overflow to
Double.POSITIVE_INFINITY when the doubleValue method was called. If
this case doesn't take too long to run, it would be a fine additional
case to add to the test. 2^1024 should be fine input value. More
precisely,
(new
BigDecimal(Double.MAX_VALUE)).toBigInteger().add(BigInteger.ONE);
should do the trick. If the code passes with this value, you're okay
to push. Well, while you're at it, might as well verify
(new BigDecimal(Double.MAX_VALUE)).toBigInteger()
behaves well too ;-)
On Dec 9, 2015, at 6:22 PM, Louis Wasserman <wasserman.lo...@gmail.com
<mailto:wasserman.lo...@gmail.com>> wrote:
Guava's tests check the explicit definition of square root (mentioned
by Joe above) on 2^n +/- 1 for all n up to Double.MAX_EXPONENT + 1,
because why not?
