EXT BITSHIFT

From Quake Wiki

Builtin definitions:

float(float number, float quantity) bitshift = #218;

Multiplies number by a power of 2 corresponding to quantity (0 = *1, 1 = *2, 2 = *4, 3 = *8, -1 = /2, -2 = /4x, etc), and rounds down (due to integer math) like other bit operations do (& and | and the like).

Note: it is faster to use multiply if you are shifting by a constant, avoiding the quakec function call cost, however that does not do a floor for you.