Compares two floating pointer numbers, and places
-1, 0, or 1 on the stack if the first is
respectively smaller, equal, or larger than the second (top)
SAM_CMPF() -
Constructor for class edu.cornell.cs.sam.core.instructions.SAM_CMPF
Base class for all SamInstructions
Defines common features such as shortcut variables and methods,
toString(), name, cpu/mem access, and an abstract
exec().