Final RFR 4837946: Faster multiplication and exponentiation of large integers

[Alan Eliasen]

On 06/18/2013 06:13 PM, Brian Burkhalter wrote:
> This RFR was initially posted last month:
> 
> http://mail.openjdk.java.net/pipermail/core-libs-dev/2013-May/016999.html
>
>  I hope that this is the final re-post. The issues in question are
> 
> http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=4837946 
> http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=4646474
> 
> and the webrev as before is at
> 
> http://cr.openjdk.java.net/~bpb/4837946/

   Brian,

   Thanks for pushing this improvement.  As I've said before, I'm more
than willing to put my personal e-mail address on this patch to support
the Karatsuba and Toom-Cook and pow() and radix conversion fixes.  I'll
put my reputation on the line.  You're free to let people e-mail me
personally if their multiplications are incorrect.  I want to support
this.  It makes Java, and pure math, implemented in Java, better.

  If there's a problem, yo, I'll solve it.  (Sorry, I channeled Vanilla
Ice there.)

   After all, I've been publishing many of these improvements for 11+
years, and I'm the person whose e-mail address comes up when someone
searches about these issues.  To be frank, I'm personally involved much
more than Sun/Oracle employees whose e-mail addresses are hidden.  I
field a *lot* of questions about making BigInteger and BigDecimal
faster.  I've helped a lot of people for many years integrate these
changes into their JVMs, which isn't easy.  I try hard.  I have many
examples of fundamental problems in BigInteger being broken for 3+ years
while I've fixed them in my own language within the day.  I am willing
to support this and fix it fast.

   I think my optimizations are simple and obvious;  after all, I posted
a list of links to undergraduate classes who are expected to implement
Karatsuba or Toom-Cook multiplication in a day or a week.  I don't want
to present myself as a genius.  I'm no better than a typical
undergraduate.

-- 
  Alan Eliasen
  eliasen at mindspring.com
  http://futureboy.us/