LROUND(3) | Library Functions Manual | LROUND(3)

# NAME

`llround`, `llroundf`, `llroundl`, `lround`, `lroundf`, `lroundl` — convert to nearest integral value

# SYNOPSIS

Math Library (libm, -lm)
`#include <math.h>`

long long
`llround`(double x);

long long
`llroundf`(float x);

long long
`llroundl`(long double x);

long
`lround`(double x);

long
`lroundf`(float x);

long
`lroundl`(long double x);

# DESCRIPTION

The `lround`() function returns the integer nearest to its argument x, rounding away from zero in halfway cases. If the rounded result is too large to be represented as a long value, an invalid exception is raised and the return value is undefined. Otherwise, if x is not an integer, `lround`() may raise an inexact exception. When the rounded result is representable as a long, the expression `lround`(x) is equivalent to (long)`round`(x) (although the former may be more efficient).

The `llround`(), `llroundf`(), `llroundl`(), `lroundf`() and `lroundl`() functions differ from `lround`() only in their input and output types.

# SEE ALSO

lrint(3), rint(3)

# STANDARDS

The `llround`(), `llroundf`(), `llroundl`(), `lround`(), `lroundf`(), and `lroundl`() functions conform to ISO/IEC 9899:1999 (“ISO C99”).

June 13, 2025 | Debian