# HPL_xjumpm man page

HPL_xjumpm — Compute constants to jump in the random sequence.

## Synopsis

**#include "hpl.h"****void HPL_xjumpm( const int** *JUMPM*, **int *** *MULT*, **int *** *IADD*, **int *** *IRANN*, **int *** *IRANM*, **int *** *IAM*, **int *** *ICM* **);**

## Description

**HPL_xjumpm** computes the constants A and C to jump JUMPM numbers in the random sequence: X(n+JUMPM) = A*X(n)+C. The constants encoded in MULT and IADD specify how to jump from one entry in the sequence to the next.

## Arguments

- JUMPM (local input) const int
- On entry, JUMPM specifies the number of entries in the sequence to jump over. When JUMPM is less or equal than zero, A and C are not computed, IRANM is set to IRANN corresponding to a jump of size zero.
- MULT (local input) int *
- On entry, MULT is an array of dimension 2, that contains the 16-lower and 15-higher bits of the constant a to jump from X(n) to X(n+1) = a*X(n) + c in the random sequence.
- IADD (local input) int *
- On entry, IADD is an array of dimension 2, that contains the 16-lower and 15-higher bits of the constant c to jump from X(n) to X(n+1) = a*X(n) + c in the random sequence.
- IRANN (local input) int *
- On entry, IRANN is an array of dimension 2. that contains the 16-lower and 15-higher bits of the encoding of X(n).
- IRANM (local output) int *
- On entry, IRANM is an array of dimension 2. On exit, this array contains respectively the 16-lower and 15-higher bits of the encoding of X(n+JUMPM).
- IAM (local output) int *
- On entry, IAM is an array of dimension 2. On exit, when JUMPM is greater than zero, this array contains the encoded constant A to jump from X(n) to X(n+JUMPM) in the random sequence. IAM(0:1) contains respectively the 16-lower and 15-higher bits of this constant A. When JUMPM is less or equal than zero, this array is not referenced.
- ICM (local output) int *
- On entry, ICM is an array of dimension 2. On exit, when JUMPM is greater than zero, this array contains the encoded constant C to jump from X(n) to X(n+JUMPM) in the random sequence. ICM(0:1) contains respectively the 16-lower and 15-higher bits of this constant C. When JUMPM is less or equal than zero, this array is not referenced.

## See Also

**HPL_ladd** (3), **HPL_lmul** (3), **HPL_setran** (3), **HPL_jumpit** (3), **HPL_rand** (3).