2 * Generally useful stuff.
12 double hypotD(const double p[D3], const double q[D3]);
13 double hypotD2(const double p[D3], const double q[D3]);
14 double hypotD2plus(const double p[D3], const double q[D3], double add);
19 # define fma_fast(f1,f2,t) ((f1)*(f2)+(t))
21 #define ffsqa(factor,term) fma_fast((factor),(factor),(term))