[squeak-dev] ArbitraryPrecisionFloat ln and exp (was: Re: LargeInteger benchmarks?)

Andreas Raab andreas.raab at gmx.de
Sat Mar 22 04:12:35 UTC 2008

nicolas cellier wrote:
> You could try using tests from ArbitraryPrecisionFloat at squeak source 
> http://www.squeaksource.com/ArbitraryPrecisionFl/.

One thing that was interesting when I was running the tests is that the 
failed for both testExpLn and testLnVsFloat. It seems like either fdlibm 
  or your code is off by one bit. For example:

(1 asArbitraryPrecisionFloatNumBits: 53) exp asFloat hex
=> '4005BF0A8B145769'

1 asFloat exp hex
=> '4005BF0A8B14576A'

(3 asArbitraryPrecisionFloatNumBits: 53) ln asFloat hex
=> '3FF193EA7AAD030B'

3 asFloat ln hex
=> '3FF193EA7AAD030A'

Any ideas what could cause this? I would have expected these two to 
agree on the result.

   - Andreas

More information about the Squeak-dev mailing list