exsplus128: xorshift128plus PRNG for Erlang

xorshift128plus is a 64-bit PRNG of (2^127-1) period.

See http://xorshift.di.unimi.it/ for the further details.

Version: 0.2.0

Note: this project is succeeded by exsplus116, the default PRNG for the rand module in OTP 18.0 and later.

Note 12-JAN-2016: the algorithm of Xorshift128+ in this code is an old one shown at https://web.archive.org/web/20150905215225/http://xorshift.di.unimi.it/. No further development will be made. Use exsplus116 instead.

LICENSE

MIT License.

(The code under c-example directory is licensed CC0/public domain.)

Note on changing the project name

This project was formerly called exsplus, but the name is changed to avoid confusion with OTP's exsplus alrorithm, which is actually Xorshift116+ (to meet the 58-bit short integer limitation in Erlang), in the rand module.

Tested platforms

• FreeBSD/amd64 10.1-STABLE with Erlang/OTP 17.5.2 and HiPE
• OS X x86_64 10.10.3 with Erlang/OTP 17.5.2 and HiPE
• HiPE is not a requirement but recommended to be enabled.
• This code will run on 18.0.

A preliminary test shows the exsplus functions takes less execution time than twice of random module on a x86_64 or amd64 architecture environment.

Make options (of erlang.mk)

• Makefile works on both BSD/GNU make
• Makefile.[module_name] is the real GNU make file; edit this file for modification
• Building: make
• Documentation: make docs
• Testing: make tests
• Execution speed benchmark: make speed
• See also erlang.mk for the details

Authors

Algorithm by Sebastiano Vigna, and he made it public domain.

Programmed by Kenji Rikitake.

Contributors

Dan Gudmundsson