

/*
 * -- SuperLU routine (version 2.0) --
 * Univ. of California Berkeley, Xerox Palo Alto Research Center,
 * and Lawrence Berkeley National Lab.
 * November 15, 1997
 *
 */
/*
  Copyright (c) 1994 by Xerox Corporation.  All rights reserved.
 
  THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY
  EXPRESSED OR IMPLIED.  ANY USE IS AT YOUR OWN RISK.
 
  Permission is hereby granted to use or copy this program for any
  purpose, provided the above notices are retained on all copies.
  Permission to modify the code and to distribute modified code is
  granted, provided the above notices are retained, and a notice that
  the code was modified is included with the above copyright notice.
*/

#include "zsp_defs.h"
#include "util.h"


/*
 * Performs numeric block updates within the relaxed snode. 
 */
int
zsnode_bmod (
	    const int  jcol,	  /* in */
	    const int  jsupno,    /* in */
	    const int  fsupc,     /* in */
	    doublecomplex     *dense,    /* in */
	    doublecomplex     *tempv,    /* working array */
	    GlobalLU_t *Glu       /* modified */
	    )
{
#ifdef USE_VENDOR_BLAS
#ifdef _CRAY
    _fcd ftcs1 = _cptofcd("L", strlen("L")),
	 ftcs2 = _cptofcd("N", strlen("N")),
	 ftcs3 = _cptofcd("U", strlen("U"));
#endif
    int            incx = 1, incy = 1;
    doublecomplex         alpha = {-1.0, 0.0},  beta = {1.0, 0.0};
#endif

    doublecomplex   comp_zero = {0.0, 0.0};
    int            luptr, nsupc, nsupr, nrow;
    int            isub, irow, i, iptr; 
    register int   ufirst, nextlu;
    int            *lsub, *xlsub;
    doublecomplex         *lusup;
    int            *xlusup;
    extern SuperLUStat_t SuperLUStat;
    flops_t *ops = SuperLUStat.ops;

    lsub    = Glu->lsub;
    xlsub   = Glu->xlsub;
    lusup   = Glu->lusup;
    xlusup  = Glu->xlusup;

    nextlu = xlusup[jcol];
    
    /*
     *	Process the supernodal portion of L\U[*,j]
     */
    for (isub = xlsub[fsupc]; isub < xlsub[fsupc+1]; isub++) {
  	irow = lsub[isub];
	lusup[nextlu] = dense[irow];
        dense[irow] = comp_zero;
	++nextlu;
    }

    xlusup[jcol + 1] = nextlu;	/* Initialize xlusup for next column */
    
    if ( fsupc < jcol ) {

	luptr = xlusup[fsupc];
	nsupr = xlsub[fsupc+1] - xlsub[fsupc];
	nsupc = jcol - fsupc;	/* Excluding jcol */
	ufirst = xlusup[jcol];	/* Points to the beginning of column
				   jcol in supernode L\U(jsupno). */
	nrow = nsupr - nsupc;

	ops[TRSV] += 4 * nsupc * (nsupc - 1);
	ops[GEMV] += 8 * nrow * nsupc;

#ifdef USE_VENDOR_BLAS
#ifdef _CRAY
	CTRSV( ftcs1, ftcs2, ftcs3, &nsupc, &lusup[luptr], &nsupr, 
	      &lusup[ufirst], &incx );
	CGEMV( ftcs2, &nrow, &nsupc, &alpha, &lusup[luptr+nsupc], &nsupr, 
		&lusup[ufirst], &incx, &beta, &lusup[ufirst+nsupc], &incy );
#else
	ztrsv_( "L", "N", "U", &nsupc, &lusup[luptr], &nsupr, 
	      &lusup[ufirst], &incx );
	zgemv_( "N", &nrow, &nsupc, &alpha, &lusup[luptr+nsupc], &nsupr, 
		&lusup[ufirst], &incx, &beta, &lusup[ufirst+nsupc], &incy );
#endif
#else
	zlsolve ( nsupr, nsupc, &lusup[luptr], &lusup[ufirst] );
	zmatvec ( nsupr, nrow, nsupc, &lusup[luptr+nsupc], 
			&lusup[ufirst], &tempv[0] );

        /* Scatter tempv[*] into lusup[*] */
	iptr = ufirst + nsupc;
	for (i = 0; i < nrow; i++) {
	    z_sub(&lusup[iptr], &lusup[iptr], &tempv[i]);
            ++iptr;
	    tempv[i] = comp_zero;
	}
#endif

    }

    return 0;
}
