[RNG-76] Add a primitive constructor to SplitMix64

• Type: Improvement
• Status: Closed
• Priority: Trivial
• Resolution: Implemented
• Affects Version/s: 1.3
• Fix Version/s: 1.3
• Component/s: core
• Assignee: Alex Herbert
• Reporter: Alex Herbert
• Created: 01/Mar/19 20:47
• Updated: 11/Nov/19 14:26
• Resolved: 30/Sep/19 10:45

Description

The constructor for SplitMix64 uses a Long for the seed. If constructed using a primitive long then auto-boxing will occur.

I added a long version of the constructor to SplitMix64:

SplitMix64(Long seed);
SplitMix64(long seed);

I modified the ConstructionPerformance benchmark to generate 5000 random seeds as Long or long then tested:

// Pre-generated Long
new SplitMix64(Long seed);

// Pre-generated long that is boxed to Long
new SplitMix64(Long.valueOf(long seed));

// Pre-generated long
new SplitMix64(long seed);

Results:

Method	Score	Error	Median
newSplitMix64Long	34.70	0.85	34.57
newSplitMix64LongValueOf	55.84	5.38	55.91
newSplitMix64long	32.66	1.49	32.46

Given that the SplitMix64 is the preferred RNG for seeding from a single long value it makes sense to add the constructor version that accepts a long.

Issue Links

• links to: GitHub Pull Request #26