Why does unity take so long to compile shader?

Hey. My surface shader is basically (in pseudo):

 float 4 col;
 
 // For each color
 int a = step(x,y);
 int b = step(y,x);
 
 col.r = a + b - 1;
 
 out.Albedo = col;

Most of the time it just freezes eternally, sometimes if I try enough times it takes just 5 minutes!!!

Dx9/Dx11 doesn't make a difference.

On 2600K @5GHz