HP MLIB User's Guide Vol. 2 7th Ed.

Chapter 11 Introduction to Distributed SuperLU 749

MPI issue when calling SuperLU_DIST8 routines

In SuperLU_DIST8 routines, integers are represented using 64-bit addressing,

which is "long long" in C. However, MPI C interfaces only accept 32-bit

addressing integers, which is "int" in C. Thus, when using 64-bit addressing

integers and calling SuperLU_DIST8 routines, for the MPI C routines you want

to call, you need to take care of the integer type conversions in your

applications.

Sample programs

1. Sample program for using the driver routine pdgssvx_ABglobal.

#include <math.h>

#include <stdlib.h>

#include “/opt/mlib/include/superlu_ddefs.h”

#define int_t int

main(int_t argc, char *argv[])

* Purpose

* =======

* This example illustrates how to use pdgssvx_ABglobal to solve

* the following linear system. The solution is

* x1=x2=x3=x4=x5=1.

* -- -- - - - -

* | 1.1 0 1.3 1.4 0 | | x1 | | 3.8 |

* | | | | | |

* | 0 0 2.3 2.4 0 | | x2 | | 4.7 |

* | | | | | |

* | 3.1 3.2 3.3 3.4 0 | | x3 | = | 13.0 |

* | | | | | |

* | 0 4.2 0 4.4 0 | | x4 | | 8.6 |

* | | | | | |

* | 5.1 5.2 0 0 5.5 | | x5 | | 15.8 |

* -- -- - - - -

* Five basic steps are required:

* 1. Initialize MPI environment and SuperLU_DIST process grid.

* 2. Set up the input matrix and the right-hand side.

* 3. Initialize the input arguments.

* 4. Call pdgssvx_ABglobal to solve the linear system.

* 5. Release the process grid and terminate the MPI environment.