HPL_grid_init(3)

💖 HPL_grid_init(3) 💖

HPL Library Functions ✨ the one where we build a whole grid of processes

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🎀 NAME 🎀

HPL_grid_init — create a process grid. bestie we're literally building the grid. no cap.

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✨ SYNOPSIS ✨

#include "hpl.h"

int HPL_grid_init( MPI_Comm COMM, const HPL_T_ORDER ORDER, const int
NPROW, const int NPCOL, HPL_T_grid * GRID );

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🦋 DESCRIPTION 🦋

Okay so HPL_grid_init creates a NPROW x NPCOL process grid, and it does it using column- or row-major ordering, starting from an initial collection of processes that get identified by an MPI communicator. That's the whole vibe. 👑

Successful completion is indicated by the returned error code MPI_SUCCESS. Any other error codes? Those depend on the MPI implementation, so like, ask your MPI, not me. 💀

Also important: the coordinates of processes that are not part of the grid get set to values outside of [0..NPROW) x [0..NPCOL). So if you're not in the grid, you're literally outside the range. not invited to the party, coordinates say so. 🚫

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🌸 ARGUMENTS 🌸

• COMM — (global/local input) MPI_Comm — On entry, COMM is the MPI communicator identifying the initial collection of processes out of which the grid is formed. it's giving guest list. 🫶
• ORDER — (global input) const HPL_T_ORDER — On entry, ORDER specifies how the processes should be ordered in the grid, like this:
  • ORDER = HPL_ROW_MAJOR — row-major ordering;
  • ORDER = HPL_COLUMN_MAJOR — column-major ordering;
• NPROW — (global input) const int — On entry, NPROW specifies the number of process rows in the grid to be created. NPROW must be at least one. minimum one, periodt. 1️⃣
• NPCOL — (global input) const int — On entry, NPCOL specifies the number of process columns in the grid to be created. NPCOL must be at least one. same energy, minimum one. 1️⃣
• GRID — (local input/output) HPL_T_grid * — On entry, GRID points to the data structure containing the process grid information to be initialized. it's the little container we're filling up. 🎀

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🌈 SEE ALSO 🌈

• HPL_pnum (3)
• HPL_grid_info (3)
• HPL_grid_exit (3)

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and that's the tea, bestie 🍓 go forth and grid-ify. mwah 💅

this was HPL 2.2, dated February 24, 2016 — iconic behavior honestly, we stan a classic 👑✨