[PATCH] Sunbug 7131192: Optimize BigInteger.doubleValue(), floatValue()

Louis Wasserman wasserman.louis at gmail.com
Thu Jul 12 09:32:49 UTC 2012


It was attached to the previous message?  I don't know if this list works
with attachments.  Alternately, the patch was attached here:
https://bugs.openjdk.java.net/show_bug.cgi?id=100222

I'm not sure what you mean by double-rounding bugs, though.  It's not
difficult to actually implement the HALF_EVEN rounding behavior with bit
twiddling.  That said, I *did* encounter places where prior erroneous
behavior (http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6358355) of
Float.parseFloat caused my correct implementation to fail tests...

Louis Wasserman
wasserman.louis at gmail.com
http://profiles.google.com/wasserman.louis


On Thu, Jul 12, 2012 at 7:58 AM, Andrew Haley <aph at redhat.com> wrote:

> On 07/11/2012 11:05 PM, Louis Wasserman wrote:
> > Doing it with bit-twiddling and Double.longBitsToDouble improves the
> speed
> > of those methods by something like two orders of magnitude in my
> benchmarks.
>
> Mmm, but that's going to hit double-rounding bugs for large numbers.  Where
> is this patch, anyway?
>
> Andrew.
>



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