cc [ flags ] -I/usr/local/include file(s) -L/usr/local/lib -lmcw [ ... ] #include <mathcw.h> extern float logbf (float x); extern double logb (double x); extern long double logbl (long double x); extern __float80 logbw (__float80 x); extern __float128 logbq (__float128 x); extern long_long_double logbll (long_long_double x); extern decimal_float logbdf (decimal_float x); extern decimal_double logbd (decimal_double x); extern decimal_long_double logbdl (decimal_long_double x); extern decimal_long_long_double logbdll (decimal_long_long_double x);
NB: Functions with prototypes containing underscores in type names may be available only with certain extended compilers.
This operation is always exact.1 <= x * FLT_RADIX**(-logb(x)) < FLT_RADIX
The companion functions scalbn(x,n) and scalbln(x,n) can be used to rescale a value whose exponent is extracted by logb(x).