RFR: 4511638: Double.toString(double) sometimes produces incorrect results [v11]

[Raffaello Giulietti]

Hi,

the aim of this PR was firstly to have a correct implementation of the 
spec. Speed improvement was a secondary goal, which was intentionally 
pursued with conventional Java arithmetic and just a few calls to simple 
methods in the standard library.

Whether the Vector API (which is still in incubation phase) might help 
in this specific case remains to be explored.

As a first impression, there seem to be no good spots to parallelize 
using SIMD instructions. But engineers with more SIMD experience might 
find creative ways to make good use of them.


HTH
Raffaello



On 2022-06-07 18:35, LifeIsStrange wrote:
> On Mon, 9 May 2022 12:50:31 GMT, Raffaello Giulietti <duke at openjdk.java.net> wrote:
> 
>>> Marked as reviewed by limck599 at github.com (no known OpenJDK username).
>>
>> @limck599
>> While we at OpenJDK appreciate constructive reviews from GitHub users not registered in the [census](https://openjdk.java.net/census), only officially nominated reviewers have the authority to approve this PR.
> 
> @rgiulietti friendly ping, noob question: Do you believe some parts of the algorithm could exploit explicit SIMD instructions (via the high level [Vector API](https://openjdk.java.net/jeps/417))  for even better performance (such as https://github.com/wrandelshofer/FastDoubleParser ) ?
> 
> -------------
> 
> PR: https://git.openjdk.java.net/jdk/pull/3402