Re: IdentityHashMap & natStackTrace

[Ranjit Mathew <rmathew at gmail dot com>]

Tom Tromey wrote:
>>>>>>"Ranjit" == Ranjit Mathew <rmathew@gmail.com> writes:
> 
> 
> Ranjit> This was introduced almost two years ago in a merge from
> Ranjit> Classpath:
> 
> Yeah, there was a wave of changing "* 2" to "<< 1".  As Bryce and
> Andrew point out, this is a non-optimization.

A grep through the libjava sources yields the following additional
suspect cases:

java/math/BigInteger.java:

   1291     // Set m such that this = 1 + 2^b * m.
   1292     BigInteger m = pMinus1.divide(valueOf(2L << b - 1));


java/text/DecimalFormatSymbols.java:

362   public int hashCode ()
363   {
364     // Compute based on zero digit, grouping separator, and decimal
365     // separator -- JCL book.  This probably isn't a very good hash
366     // code.
367     return zeroDigit << 16 + groupingSeparator << 8 + decimalSeparator;

Ranjit.

-- 
Ranjit Mathew          Email: rmathew AT gmail DOT com

Bangalore, INDIA.      Web: http://ranjitmathew.tripod.com/