SCALBLN(3M) Mathematical Library Functions SCALBLN(3M)

scalbln, scalblnf, scalblnl, scalbn, scalbnf, scalbnl - compute exponent using FLT_RADIX

c99 [ flag... ] file... -lm [ library... ]
#include <math.h>
double scalbln(double x, long n);

float scalblnf(float x, long n);

long double scalblnl(long double x, long n);

double scalbn(double x, int n);

float scalbnf(float x, int n);

long double scalbnl(long double x, int n);

These functions compute x * FLT_RADIX^n efficiently, not normally by computing FLT_RADIX^n explicitly.

Upon successful completion, these functions return x * FLT_RADIX^n>.

If the result would cause overflow, a range error occurs and these functions return ±HUGE_VAL, ±HUGE_VALF, and ±HUGE_VALL (according to the sign of x) as appropriate for the return type of the function.

If x is NaN, a NaN is returned.

If x is ±0 or ±Inf, x is returned.

If x is 0, x is returned.

These functions will fail if:

Range Error

The result overflows.

If the integer expression (math_errhandling & MATH_ERREXCEPT) is non-zero, then the overflow floating-point exception is raised.

An application wanting to check for exceptions should call feclearexcept(FE_ALL_EXCEPT) before calling these functions. On return, if fetestexcept(FE_INVALID | FE_DIVBYZERO | FE_OVERFLOW | FE_UNDERFLOW) is non-zero, an exception has been raised. An application should either examine the return value or check the floating point exception flags to detect exceptions.

See attributes(7) for descriptions of the following attributes:

Interface Stability Standard
MT-Level MT-Safe

math.h(3HEAD), feclearexcept(3M), fetestexcept(3M), scalb(3M), attributes(7), standards(7)

July 12, 2006 SunOS 5.11