cc [ flags ] -I/usr/local/include file(s) -L/usr/local/lib -lmcw [ ... ] #include <mathcw.h> extern float rsqrtf (float x); extern double rsqrt (double x); extern long double rsqrtl (long double x); extern __float80 rsqrtw (__float80 x); extern __float128 rsqrtq (__float128 x); extern long_long_double rsqrtll (long_long_double x); extern decimal_float rsqrtdf (decimal_float x); extern decimal_double rsqrtd (decimal_double x); extern decimal_long_double rsqrtdl (decimal_long_double x); extern decimal_long_long_double rsqrtdll (decimal_long_long_double x);
NB: Functions with prototypes containing underscores in type names may be available only with certain extended compilers.
This function is more accurate than using 1.0/sqrt(x), since it can avoid an additional rounding error from the division.