llround(3)

llround3

Convert to nearest integral value

Part of lround(3).

Usage

#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);

Library

Math Library (libm, -lm)

Overview

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.

Releases

51 releases since FreeBSD 5.4-RELEASE; the text changed 33 times.

  1. 5.4–5.5
  2. 6.0–6.3
  3. 6.4
  4. 7.0
  5. 7.1
  6. 7.2
  7. 7.3
  8. 7.4
  9. 8.0
  10. 8.1
  11. 8.2
  12. 8.3
  13. 8.4
  14. 9.0
  15. 9.1
  16. 9.2
  17. 9.3
  18. 10.0
  19. 10.1
  20. 10.2
  21. 10.3
  22. 10.4
  23. 11.0
  24. 11.1
  25. 11.2
  26. 11.3
  27. 11.4
  28. 12.0
  29. 12.1
  30. 12.2
  31. 12.3
  32. 12.4
  33. 13.0–13.2
  34. 13.3–16.0

Standards

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

History

The float and double versions of these routines first appeared in FreeBSD 5.4. The long double versions appeared in FreeBSD 6.0.

From base 16.0-CURRENT-20261027-61c70dc16a79 in FreeBSD 16.0-CURRENT (2026-10-27). Parsed by carta from the page's mdoc source.