ldexpl3
Multiply floating-point number by integral power of 2
Part of ldexp(3).
Usage
#include <math.h>
double ldexp(double x, int e); float ldexpf(float x, int e); long double ldexpl(long double x, int e);
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
ldexpf(), ldexpl():
_ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L
|| /* Since glibc 2.19: */ _DEFAULT_SOURCE
|| /* glibc <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE
Library
Math library (libm, -lm)
Overview
These functions return the result of multiplying the floating-point number x by 2 raised to the power e.
Return value
On success, these functions return x * (2^e).
If e is zero, then x is returned.
If x is a NaN, a NaN is returned.
If x is positive infinity (negative infinity), positive infinity (negative infinity) is returned.
If the result underflows, a range error occurs, and zero is returned.
If the result overflows, a range error occurs, and the functions return HUGE_VAL, HUGE_VALF, or HUGE_VALL, respectively, with a sign the same as x.
Errors
See math_error(7) for information on how to determine whether an error has occurred when calling these functions.
The following errors can occur:
- Range error, overflow
-
errno is set to ERANGE. An overflow floating-point exception (
FE_OVERFLOW) is raised.
- Range error, underflow
-
errno is set to ERANGE. An underflow floating-point exception (
FE_UNDERFLOW) is raised.
Attributes
For an explanation of the terms used in this section, see attributes(7).
| Interface | Attribute | Value |
| ldexp(), ldexpf(), ldexpl() | Thread safety | MT-Safe |
Releases
12 releases since Debian 3.1 (Sarge); the text changed 11 times.