Rounding differences between 1.8 and 1.7 (including -Xint mode).

Vladimir Kozlov vladimir.kozlov at oracle.com
Fri Jul 20 15:16:47 PDT 2012


Dawid,

It would be nice if you can provide a test case for us. What jdk8 build you are 
using?

We recently changed implementation of exp() and pow() in VM on x86 from C code 
to use FPU instructions. It created a bugs tail. The latest bug 7177917 was 
fixed in jdk8b48.

Thanks,
Vladimir

Dawid Weiss wrote:
> Hi everyone.
> 
> We observe test regressions on fairly complex computational code
> resulting from small differences in double roundings. They show up
> when executed with latest 1.8 snapshot (compared to 1.7 and 1.6). Also
> applies when run in interpreted mode (-Xint).
> 
> I was wondering if this is something to be expected? Thanks,
> 
> Dawid


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