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/* ========================================================================== */
/* === UMF_fsize ============================================================ */
/* ========================================================================== */

/* -------------------------------------------------------------------------- */
/* UMFPACK Version 4.5, Copyright (c) 2005 by Timothy A. Davis.  CISE Dept,   */
/* Univ. of Florida.  All Rights Reserved.  See ../Doc/License for License.   */
/* web: http://www.cise.ufl.edu/research/sparse/umfpack                       */
/* -------------------------------------------------------------------------- */

/* Determine the largest frontal matrix size for each subtree.   Called by
 * UMF_colamd and UMF_analyze.  Only required to sort the children of each
 * node prior to AMD_postorder. */

#include "umf_internal.h"

GLOBAL void UMF_fsize
(
    Int nn,
    Int Fsize [ ],
    Int Fnrows [ ],
    Int Fncols [ ],
    Int Parent [ ],
    Int Npiv [ ]
)
{
    Int j, parent, frsize, r, c ;

    for (j = 0 ; j < nn ; j++)
    {
    Fsize [j] = EMPTY ;
    }

    /* ---------------------------------------------------------------------- */
    /* find max front size for tree rooted at node j, for each front j */
    /* ---------------------------------------------------------------------- */

    DEBUG1 (("\n\n========================================FRONTS:\n")) ;
    for (j = 0 ; j < nn ; j++)
    {
    if (Npiv [j] > 0)
    {
        /* this is a frontal matrix */
        parent = Parent [j] ;
        r = Fnrows [j] ;
        c = Fncols [j] ;
        frsize = r * c ;
        /* avoid integer overflow */
        if (INT_OVERFLOW (((double) r) * ((double) c)))
        {
        /* :: frsize int overflow :: */
        frsize = Int_MAX ;
        }
        DEBUG1 ((""ID" : npiv "ID" size "ID" parent "ID" ",
        j, Npiv [j], frsize, parent)) ;
        Fsize [j] = MAX (Fsize [j], frsize) ;
        DEBUG1 (("Fsize [j = "ID"] = "ID"\n", j, Fsize [j])) ;
        if (parent != EMPTY)
        {
        /* find the maximum frontsize of self and children */
        ASSERT (Npiv [parent] > 0) ;
        ASSERT (parent > j) ;
        Fsize [parent] = MAX (Fsize [parent], Fsize [j]) ;
        DEBUG1 (("Fsize [parent = "ID"] = "ID"\n",
            parent, Fsize [parent]));
        }
    }
    }
}