lrint(), lrintf(), lrintl() and llrint(), llrintf(), llrintl() -- Round the argument to the nearest

lrint(), lrintf(), lrintl() and llrint(), llrintf(), llrintl() -- Round the argument to the nearest integer

z/OS V1R12.0 XL C/C++ Run-Time Library Reference
SA22-7821-12 

Standards

Standards / ExtensionsC or C++Dependencies

C99
Single UNIX® Specification, Version 3
C++ TR1 C99

both z/OS V1R7

Format

#define _ISOC99_SOURCE#include <math.h>long int lrint(double x);long int lrintf(float x);long int lrintl(long double x);long long int llrint(double x);long long int llrintf(float x);long long int llrintl(long double x);

C++ TR1 C99:

#define _TR1_C99#include <math.h>long int lrint(float x);long int lrint(long double x);long long int llrint(float x);long long int llrint(long double x);

Compile requirement:

The llrint() family of functions requires the long long data type. See z/OS XL C/C++ Language Reference for information on how to make long long available.

General description

The lrint() and llrint() families of functions round their argument to the nearest integer value according to the current rounding mode. If the rounded value is outside the range of the return type, the numeric result is unspecified. A range error may occur if the magnitude of x is too large.

Note:

The following table shows the viable formats for these functions. See IEEE binary floating-point for more information about IEEE Binary Floating-Point.FunctionHexIEEElrintXXlrintfXXlrintlXXllrintXXllrintfXXllrintlXX

Returned value

If successful, they return the rounded integer value. If the correct value is positive or negative and too large to represent as a long (lrint() family) or long long (llrint() family), a domain error will occur and an unspecified value is returned.

Example

/* * This program illustrates the use of lrint() function * * Note: To get the output shown in this  information, this program  *       should be compiled using FLOAT(IEEE) * */#define _ISOC99_SOURCE#include <math.h>#include <stdio.h>#include <_Ieee754.h>   /* save/get fpc functions   */char *RoundStr (_FP_rmode_t rm_type) {  char *RndStr="undetermined";   switch (rm_type) {     case (_RMODE_RN):        RndStr="round to nearest";        break;     case (_RMODE_RZ):        RndStr="round toward zero";        break;     case (_RMODE_RP):        RndStr="round toward +infinity ";        break;     case (_RMODE_RM):        RndStr="round toward -infinity ";        break;   }   return (RndStr);}void main() {  _FP_fpcreg_t save_rmode, current_rmode;  long int     rnd2nearest;  double       number=500.99;  printf("Illustrates the lrint() function\n");  __fpc_rd(&current_rmode);     /* get current rounding mode */  rnd2nearest = lrint(number);  printf ("When rounding direction is %s:\n lrint(%.2f) = %li\n",RoundStr(current_rmode.rmode), number, rnd2nearest);  save_rmode.rmode = _RMODE_RZ;  __fpc_sm(save_rmode.rmode);   /* set rounding mode to round to zero */  rnd2nearest = lrint(number);  printf ("When rounding direction is %s:\n lrint(%.2f) = %li\n",RoundStr(save_rmode.rmode), number, rnd2nearest);}OutputIllustrates the lrint() functionWhen rounding direction is round to nearest: lrint(500.99) = 501When rounding direction is round toward zero: lrint(500.99) = 500

Related information

• math.h
• ceil(), ceilf(), ceill() — Round up to integral value
• floor(), floorf(), floorl() — Round down to integral value
• llround(), llroundf(), llroundl() -- Round to the nearest integer
• lround(), lroundf(), lroundl() — Round a decimal floating-point number to its nearest integer
• nearbyint(), nearbyintf(), nearbyintl() -- Round the argument to the nearest integer
• rint(), rintf(), rintl() — Round to nearest integral value
• round(), roundf(), roundl() -- Round to the nearest integer
• trunc(), truncf(), truncl() — Truncate an integer value

http://pic.dhe.ibm.com/infocenter/zos/v1r12/index.jsp?topic=%2Fcom.ibm.zos.r12.bpxbd00%2Flrint.htm

http://www.cplusplus.com/reference/cmath/lrint/