Reverse Engineering challenge #88.

This is my programmer's calculator, but two undocumented functions has been added.

1) Named secret(), takes two arguments. What does it do? Hint: running it with various arguments can give a hint.

Programmer's calculator (Jul 27 2017)
Modified version for
[1] secret(1,2)
[1] (unsigned) 4 0x4 0b100
[2] secret(1,6)
[2] (unsigned) 8 0x8 0b1000
[3] secret(2,4)
[3] (unsigned) 11 0xb 0b1011
[4] secret(3,3)
[4] (unsigned) 61 0x3d 0b111101 ASCII: '='

It is a well-known function, the article about in in Wikipedia has ~300 in links (what links here).

2) No name known. Try to find it.

Downloads: Win64, Linux64.

More challenges:; about solutions: