SCALBN(3) BSD Library Functions Manual SCALBN(3)
scalbn, scalbnf, scalbnl -- exponent using FLT_RADIX
Math Library (libm, -lm)
scalbn(double x, int n);
scalbnf(float x, int n);
scalbnl(long double x, int n);
The scalbn(), scalbnf(), and scalbnl() functions compute x * r^n, where r is the radix of
the machine's floating point arithmetic, defined by the FLT_RADIX constant in <float.h>.
The rationale is efficiency; r^n is not computed explicitly.
As described above, upon successful completion, the described functions return the exponent
computed using FLT_RADIX. Otherwise the following may occur:
1. When the result would cause an overflow, a range error occurs and +-HUGE_VAL,
+-HUGE_VALF, or +-HUGE_VALL is returned according to the sign of x and the return
type of the corresponding function.
2. When the correct value would cause an underflow and it is not representable, a
range error occurs and either 0.0 or an implementation-defined value is returned.
When an underflow occurs but the correct value is representable, a range error
occurs but the correct value is returned.
3. If x is +-0 or +-Inf, x is returned. Likewise, if n is zero, x is returned. If
x is NaN, NaN is returned.
exp(3), frexp(3), ldexp(3), math(3)
The described functions conform to ISO/IEC 9899:1999 (``ISO C99'').
BSD September 18, 2011 BSD