RFR: JDK-8283124: Add constant for tau to Math and StrictMath

[Joseph D. Darcy]

Hi Raffaello,

With changing TAU to be set to 2.0 * PI, I'll file a follow-up bug to 
use the least-precision decimal values that will get rounded to PI and 
E, respectively, in Math and StrictMath. (Per the general base 
conversion properties for the double format, there will be between 15 
and 17 decimal digits rather than 21.)

Thanks,

-Joe

On 3/14/2022 2:32 PM, Raffaello Giulietti wrote:
> Hello,
>
> I find it a bit disturbing that PI is specified with 21 digits whereas 
> TAU has 16.
> I think that specifying PI as
>     public static final double PI = 3.141592653589793;
> doesn't harm anybody and makes it visually more consistent with TAU-
>
>
> Greetings
> Raffaello
>
>
>
> On 3/14/22 22:13, Brian Burkhalter wrote:
>> On Mon, 14 Mar 2022 20:52:39 GMT, Joe Darcy <darcy at openjdk.org> wrote:
>>
>>> Add a constant for tau, 2*pi, to Math and StrictMath. Since 2*pi is 
>>> a very common value in mathematical formulas, it is helpful to give 
>>> it a distinct constant.
>>>
>>> Please also review the CSR 
>>> https://bugs.openjdk.java.net/browse/JDK-8283136
>>
>> Marked as reviewed by bpb (Reviewer).
>>
>> -------------
>>
>> PR: https://git.openjdk.java.net/jdk/pull/7813