The types of floating-point linkage are:
Software floating-point linkage means that the parameters and return value for a function
are passed using the ARM integer registers
Hardware floating-point linkage uses the Vector
Floating-Point (VFP) coprocessor registers to pass the arguments and return
The benefit of using software floating-point linkage is that the resulting code can be run
on a processor with or without a VFP coprocessor. It is not dependent on the presence of a
VFP hardware coprocessor, and it can be used with or without a VFP coprocessor present.
The benefit of using hardware floating-point linkage is that it is more efficient than
software floating-point linkage, but you must have a VFP coprocessor.