# HPL_equil man page

HPL_equil — Equilibrate U and forward the column panel L.

## Synopsis

**#include "hpl.h"****void HPL_equil( HPL_T_panel *** *PBCST*, **int *** *IFLAG*, **HPL_T_panel *** *PANEL*, **const enum HPL_TRANS** *TRANS*, **const int** *N*, **double *** *U*, **const int** *LDU*, **int *** *IPLEN*, **const int *** *IPMAP*, **const int *** *IPMAPM1*, **int *** *IWORK* **);**

## Description

**HPL_equil** equilibrates the local pieces of U, so that on exit to this function, pieces of U contained in every process row are of the same size. This phase makes the rolling phase optimal. In addition, this function probes for the column panel L and forwards it when possible.

## Arguments

- PBCST (local input/output) HPL_T_panel *
- On entry, PBCST points to the data structure containing the panel (to be broadcast) information.
- IFLAG (local input/output) int *
- On entry, IFLAG indicates whether or not the broadcast has already been completed. If not, probing will occur, and the outcome will be contained in IFLAG on exit.
- PANEL (local input/output) HPL_T_panel *
- On entry, PANEL points to the data structure containing the panel (to be equilibrated) information.
- TRANS (global input) const enum HPL_TRANS
- On entry, TRANS specifies whether U is stored in transposed or non-transposed form.
- N (local input) const int
- On entry, N specifies the number of rows or columns of U. N must be at least 0.
- U (local input/output) double *
- On entry, U is an array of dimension (LDU,*) containing the local pieces of U in each process row.
- LDU (local input) const int
- On entry, LDU specifies the local leading dimension of U. LDU should be at least MAX(1,IPLEN[nprow]) when U is stored in non-transposed form, and MAX(1,N) otherwise.
- IPLEN (global input) int *
- On entry, IPLEN is an array of dimension NPROW+1. This array is such that IPLEN[i+1] - IPLEN[i] is the number of rows of U in process IPMAP[i].
- IPMAP (global input) const int *
- On entry, IPMAP is an array of dimension NPROW. This array contains the logarithmic mapping of the processes. In other words, IPMAP[myrow] is the absolute coordinate of the sorted process.
- IPMAPM1 (global input) const int *
- On entry, IPMAPM1 is an array of dimension NPROW. This array contains the inverse of the logarithmic mapping contained in IPMAP: For i in [0.. NPROCS) IPMAPM1[IPMAP[i]] = i.
- IWORK (workspace) int *
- On entry, IWORK is a workarray of dimension NPROW+1.

## See Also

**HPL_pdlaswp01N** (3), **HPL_pdlaswp01T** (3).