__softfp keyword asserts that a function
uses software floating-point linkage.
__softfp is a function qualifier. It affects
the type of the function.
This keyword has the
Calls to the function pass floating-point arguments in integer registers. If the result is a floating-point value, the value is returned in integer registers. This duplicates the behavior of compilation targeting software floating-point.
This keyword enables the same library to be used by sources compiled to use hardware and software floating-point.
In C++, if a virtual function qualified with the
is to be overridden, the overriding function must also be declared
__softfp. If the functions do not match, the compiler
generates an error.