XORSHIFT-ADD (XSadd)

XORSHIFT-ADD (XSadd):
A variant of XORSHIFT ^*1.

News

XSadd ver.1.2 is released. Version 1.1 has serious bugs.(2015/4/24)
XSadd ver.1.1 is released. (2014/3/24)
XSadd ver.1.0 is released. (2014/2/15)

What is XORSHIFT-ADD

XORSHIFT^*2 developed by George Marsagria is a widely used small-sized pesudorandom number generator. Here, a modified version XORSHIFT-ADD is introduced by Mutsuo Saito and Makoto Matsumoto (February 2014). XORSHIFT-ADD has an 128-bit internal state and period of 2¹²⁸-1, and passes the bigcrush test of TestU01 test suite.

XORSHIFT-ADD is intended to be better than XORWOW^*2; smaller, faster and better score in statistical tests. XORSHIFT-ADD is also smaller and faster than TinyMT.

XORSHIFT-ADD has following features:

The period of the generated sequence is 2¹²⁸-1.
The size of the internal state space is 128 bits.
The state transition function is F₂-linear.
The output function is not F₂-linear.
No systematic failure is observed through the BigCrush test suite.

Download XORSHIFT-ADD(XSadd)

This code is released on February 15th in 2014, and it may contain some bugs. Any feedback is welcome (send an email to Mutsuo Saito, saito "at sign" manieth.com and m-mat "at sign" math.sci.hiroshima-u.ac.jp)

version	archive	changes
1.2	Please download from GitHub XSadd	Bug fix of floating point conversion. This bug is SERIOUS. In version 1.1, xsadd_float() and xsadd_double() may return 1.0 and xsadd_floatOC() may return 0.0. (2015/4/24)
1.1	XSadd-src-1.1.zip XSadd-src-1.1.tar.gz	Bug fix of the period certification function. Output sequences may change. (2014/3/24) This version has SERIOUS BUGS. Use version 1.2. In version 1.1, xsadd_float() and xsadd_double() may return 1.0 and xsadd_floatOC() may return 0.0. (2015/4/24)
1.0	XSadd-src-1.0.zip XSadd-src-1.0.tar.gz	The first version. (2014/2/15)

If you have any trouble to download, try this page.

License

XSadd, as well as MT, can be used freely for any purpose, including commercial use. See LICENSE.txt for detail.

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*1 This work is partially supported by JSPS Grant-in-Aid for Scientific Research No. 23244002, 24654019.

*2 Marsaglia, George. "Xorshift rngs." Journal of Statistical Software 8.14 (2003): 1-6.