> Nope, the compiler doesn't use them.  But -mhard-float changes the calling
> convention for floating point functions.  Code compiled -mhard-float
> expects a floating point result to be returned in a floating point
> register; code compiled -msoft-float expects it in r0(+r1 for doubles).
> So the problem is that you cannot link the system libraries into your
> program if you are expecting floating point results back.

Just out of academic interest how feasible would it be/what would be the
major downside to having a gcc option that passed FP arguments on the
stack/in integer registers for function calls, but used the FPA otherwise.
Would this not permit interoperation between soft-float and hard-float
code?

Cheers,

David.

PS - Just for clarity: I'm not actually suggesting we do this, I'm just
interested in understanding the issues.