nearbyint(), nearbyintf(), nearbyintl()
QNX SDP8.0C Library ReferenceAPIDeveloper
Return a rounded integer value
Synopsis:
#include <math.h>
double nearbyint( double x);
float nearbyintf( float x);
long double nearbyintl( long double x);
Arguments:
- x
- The number that you want to round.
Library:
- libm
- The general-purpose math library.
- libm-sve
- A library that optimizes the code for ARMv8.2 chips that have Scalable Vector Extension hardware.
Your system requirements will determine how you should work with these libraries:
- If you want only selected processes to run with the SVE version, you can include both libraries in your OS image and use the -l m or -l m-sve option to qcc to link explicitly against the appropriate one.
- If you want all processes to use the SVE version, include libm-sve.so in your OS image and set up a symbolic link from libm.so to libm-sve.so. Use the -l m option to qcc to link against the library.
Note:
Compile your program with the -fno-builtin option to prevent the compiler from using a
built-in version of the function.
Description:
The nearbyint(), nearbyintf(), and nearbyintl() functions round their argument to an integer value in floating-point format, using the current rounding direction and without raising the inexact floating-point exception.
To check for error situations, use feclearexcept() and fetestexcept(). For example:
- Call
feclearexcept(FE_ALL_EXCEPT)
before calling nearbyint(), nearbyintf(), or nearbyintl(). - On return, if
fetestexcept(FE_ALL_EXCEPT)
is nonzero, then an error has occurred.
Returns:
The rounded integer value, with the same sign as x.
If x is: | These functions return: | Errors: |
---|---|---|
±0.0 | ±0.0 | — |
±Inf | x | — |
NaN | NaN | — |
These functions raise FE_INEXACT if the FPU reports that the result can't be exactly represented as a floating-point number.
Classification:
Safety: | |
---|---|
Cancellation point | No |
Signal handler | Yes |
Thread | Yes |
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