Load the exponent of a radix-independent floating point number
#include <math.h> double scalbln ( double x, long int n ); float scalblnf ( float x, long int n ); long double scalblnl ( long double x, long int n );
The scalbln(), scalblnf(), and scalblnl() functions compute x × r^{n}, where r is the radix of the machine's floating-point arithmetic. The difference between the scalbn* and scalbln* functions is the type of the second argument.
To check for error situations, use feclearexcept() and fetestexcept(). For example:
x × r^{n}
If: | These functions return: | Errors: |
---|---|---|
x is NaN | NaN | — |
x is ±0.0 or ±Inf | x | — |
n is 0 | x | — |
The correct value would cause underflow | The correct value, after rounding | FE_UNDERFLOW |
The correct value would cause overflow | Inf | FE_OVERFLOW |
These functions raise FE_INEXACT if the FPU reports that the result can't be exactly represented as a floating-point number.
Safety: | |
---|---|
Cancellation point | No |
Interrupt handler | No |
Signal handler | No |
Thread | Yes |