/*! \file
Copyright (c) 2003, The Regents of the University of California, through
Lawrence Berkeley National Laboratory (subject to receipt of any required 
approvals from U.S. Dept. of Energy) 

All rights reserved. 

The source code is distributed under BSD license, see the file License.txt
at the top-level directory.
*/


/*! @file 
 * \brief Driver program for pdgssvx_ABglobal example
 *
 * <pre>
 * -- Distributed SuperLU routine (version 4.1) --
 * Lawrence Berkeley National Lab, Univ. of California Berkeley.
 * September 1, 1999
 * April 5, 2015
 * </pre>
 */

#include <math.h>
#include "superlu_ddefs.h"

/*! \brief
 *
 * <pre>
 * Purpose
 * =======
 *
 * The driver program pddrive1_ABglobal.
 *
 * This example illustrates how to use pdgssvx_ABglobal to
 * solve systems with the same A but different right-hand side.
 * In this case, we factorize A only once in the first call to
 * pdgssvx_ABglobal, and reuse the following data structures
 * in the subsequent call to pdgssvx_ABglobal:
 *        ScalePermstruct  : DiagScale, R, C, perm_r, perm_c
 *        LUstruct         : Glu_persist, Llu
 * 
 * On an IBM SP, the program may be run by typing:
 *    poe pddrive1_ABglobal -r <proc rows> -c <proc columns> <input_matrix> -procs <p>
 * </pre>
 */

int main(int argc, char *argv[])
{
    superlu_dist_options_t options;
    SuperLUStat_t stat;
    SuperMatrix A;
    dScalePermstruct_t ScalePermstruct;
    dLUstruct_t LUstruct;
    gridinfo_t grid;
    double   *berr;
    double   *a, *b, *b1, *xtrue;
    int_t    *asub, *xa;
    int_t    i, j, m, n, nnz;
    int_t    nprow, npcol;
    int      iam, info, ldb, ldx, nrhs;
    char     trans[1];
    char     **cpp, c;
    FILE *fp, *fopen();
    extern int cpp_defs();

    nprow = 1;  /* Default process rows.      */
    npcol = 1;  /* Default process columns.   */
    nrhs = 1;   /* Number of right-hand side. */

    /* ------------------------------------------------------------
       INITIALIZE MPI ENVIRONMENT. 
       ------------------------------------------------------------*/
    MPI_Init( &argc, &argv );
#ifdef GPU_ACC
    int rank, devs;
    MPI_Comm_rank(MPI_COMM_WORLD, &rank);
    cudaGetDeviceCount(&devs);
    cudaSetDevice(rank % devs);
#endif

    /* Parse command line argv[]. */
    for (cpp = argv+1; *cpp; ++cpp) {
	if ( **cpp == '-' ) {
	    c = *(*cpp+1);
	    ++cpp;
	    switch (c) {
	      case 'h':
		  printf("Options:\n");
		  printf("\t-r <int>: process rows    (default " IFMT ")\n", nprow);
		  printf("\t-c <int>: process columns (default " IFMT ")\n", npcol);
		  exit(0);
		  break;
	      case 'r': nprow = atoi(*cpp);
		        break;
	      case 'c': npcol = atoi(*cpp);
		        break;
	    }
	} else { /* Last arg is considered a filename */
	    if ( !(fp = fopen(*cpp, "r")) ) {
                ABORT("File does not exist");
            }
	    break;
	}
    }

    /* ------------------------------------------------------------
       INITIALIZE THE SUPERLU PROCESS GRID. 
       ------------------------------------------------------------*/
    superlu_gridinit(MPI_COMM_WORLD, nprow, npcol, &grid);

    /* Bail out if I do not belong in the grid. */
    iam = grid.iam;
    if ( iam == -1 ) goto out;
    
#if ( DEBUGlevel>=1 )
    CHECK_MALLOC(iam, "Enter main()");
#endif
    
    /* ------------------------------------------------------------
       PROCESS 0 READS THE MATRIX A, AND THEN BROADCASTS IT TO ALL
       THE OTHER PROCESSES.
       ------------------------------------------------------------*/
    if ( !iam ) {
	/* Print the CPP definitions. */
	cpp_defs();
	
	/* Read the matrix stored on disk in Harwell-Boeing format. */
	dreadhb_dist(iam, fp, &m, &n, &nnz, &a, &asub, &xa);
	
	printf("Input matrix file: %s\n", *cpp);
	printf("\tDimension\t" IFMT "x" IFMT "\t # nonzeros " IFMT "\n", m, n, nnz);
	printf("\tProcess grid\t%d X %d\n", (int) grid.nprow, (int) grid.npcol);

	/* Broadcast matrix A to the other PEs. */
	MPI_Bcast( &m,   1,   mpi_int_t,  0, grid.comm );
	MPI_Bcast( &n,   1,   mpi_int_t,  0, grid.comm );
	MPI_Bcast( &nnz, 1,   mpi_int_t,  0, grid.comm );
	MPI_Bcast( a,    nnz, MPI_DOUBLE, 0, grid.comm );
	MPI_Bcast( asub, nnz, mpi_int_t,  0, grid.comm );
	MPI_Bcast( xa,   n+1, mpi_int_t,  0, grid.comm );
    } else {
	/* Receive matrix A from PE 0. */
	MPI_Bcast( &m,   1,   mpi_int_t,  0, grid.comm );
	MPI_Bcast( &n,   1,   mpi_int_t,  0, grid.comm );
	MPI_Bcast( &nnz, 1,   mpi_int_t,  0, grid.comm );

	/* Allocate storage for compressed column representation. */
	dallocateA_dist(n, nnz, &a, &asub, &xa);

	MPI_Bcast( a,    nnz, MPI_DOUBLE, 0, grid.comm );
	MPI_Bcast( asub, nnz, mpi_int_t,  0, grid.comm );
	MPI_Bcast( xa,   n+1, mpi_int_t,  0, grid.comm );
    }
	
    /* Create compressed column matrix for A. */
    dCreate_CompCol_Matrix_dist(&A, m, n, nnz, a, asub, xa,
				SLU_NC, SLU_D, SLU_GE);

    /* Generate the exact solution and compute the right-hand side. */
    if ( !(b = doubleMalloc_dist(m * nrhs)) ) ABORT("Malloc fails for b[]");
    if ( !(b1 = doubleMalloc_dist(m * nrhs)) ) ABORT("Malloc fails for b1[]");
    if ( !(xtrue = doubleMalloc_dist(n*nrhs)) ) ABORT("Malloc fails for xtrue[]");
    *trans = 'N';
    ldx = n;
    ldb = m;
    dGenXtrue_dist(n, nrhs, xtrue, ldx);
    dFillRHS_dist(trans, nrhs, xtrue, ldx, &A, b, ldb);
    for (j = 0; j < nrhs; ++j)
	for (i = 0; i < m; ++i) b1[i+j*ldb] = b[i+j*ldb];

    if ( !(berr = doubleMalloc_dist(nrhs)) )
	ABORT("Malloc fails for berr[].");

    /* ------------------------------------------------------------
       WE SOLVE THE LINEAR SYSTEM FOR THE FIRST TIME.
       ------------------------------------------------------------*/

    /* Set the default input options:
        options.Fact = DOFACT;
        options.Equil = YES;
        options.ColPerm = METIS_AT_PLUS_A;
        options.RowPerm = LargeDiag_MC64;
        options.ReplaceTinyPivot = YES;
        options.Trans = NOTRANS;
        options.IterRefine = DOUBLE;
        options.SolveInitialized = NO;
        options.RefineInitialized = NO;
        options.PrintStat = YES;
     */
    set_default_options_dist(&options);

    if (!iam) {
	print_sp_ienv_dist(&options);
	print_options_dist(&options);
    }

    /* Initialize ScalePermstruct and LUstruct. */
    dScalePermstructInit(m, n, &ScalePermstruct);
    dLUstructInit(n, &LUstruct);

    /* Initialize the statistics variables. */
    PStatInit(&stat);

    /* Call the linear equation solver: factorize and solve. */
    pdgssvx_ABglobal(&options, &A, &ScalePermstruct, b, ldb, nrhs, &grid,
		     &LUstruct, berr, &stat, &info);

    /* Check the accuracy of the solution. */
    if ( !iam ) {
	dinf_norm_error_dist(n, nrhs, b, ldb, xtrue, ldx, &grid);
    }

    PStatPrint(&options, &stat, &grid);        /* Print the statistics. */
    PStatFree(&stat);

    /* ------------------------------------------------------------
       NOW WE SOLVE ANOTHER SYSTEM WITH THE SAME A BUT DIFFERENT
       RIGHT-HAND SIDE,  WE WILL USE THE EXISTING L AND U FACTORS IN
       LUSTRUCT OBTAINED FROM A PREVIOUS FATORIZATION.
       ------------------------------------------------------------*/
    options.Fact = FACTORED; /* Indicate the factored form of A is supplied. */
    PStatInit(&stat); /* Initialize the statistics variables. */

    pdgssvx_ABglobal(&options, &A, &ScalePermstruct, b1, ldb, nrhs, &grid,
		     &LUstruct, berr, &stat, &info);

    /* Check the accuracy of the solution. */
    if ( !iam ) {
	printf("Solve the system with a different B.\n");
	dinf_norm_error_dist(n, nrhs, b1, ldb, xtrue, ldx, &grid);
    }

    /* Print the statistics. */
    PStatPrint(&options, &stat, &grid);

    /* ------------------------------------------------------------
       DEALLOCATE STORAGE.
       ------------------------------------------------------------*/
    PStatFree(&stat);
    Destroy_CompCol_Matrix_dist(&A);
    dDestroy_LU(n, &grid, &LUstruct);
    dScalePermstructFree(&ScalePermstruct);
    dLUstructFree(&LUstruct);
    SUPERLU_FREE(b);
    SUPERLU_FREE(b1);
    SUPERLU_FREE(xtrue);
    SUPERLU_FREE(berr);
    fclose(fp);

    /* ------------------------------------------------------------
       RELEASE THE SUPERLU PROCESS GRID.
       ------------------------------------------------------------*/
out:
    superlu_gridexit(&grid);

    /* ------------------------------------------------------------
       TERMINATES THE MPI EXECUTION ENVIRONMENT.
       ------------------------------------------------------------*/
    MPI_Finalize();

#if ( DEBUGlevel>=1 )
    CHECK_MALLOC(iam, "Exit main()");
#endif

}


int cpp_defs()
{
    printf(".. CPP definitions:\n");
#if ( PRNTlevel>=1 )
    printf("\tPRNTlevel = %d\n", PRNTlevel);
#endif
#if ( DEBUGlevel>=1 )
    printf("\tDEBUGlevel = %d\n", DEBUGlevel);
#endif
#if ( PROFlevel>=1 )
    printf("\tPROFlevel = %d\n", PROFlevel);
#endif
#if ( StaticPivot>=1 )
    printf("\tStaticPivot = %d\n", StaticPivot);
#endif
    printf("....\n");
    return 0;
}
