text: /* Copyright 2004,2007,2009-2012 IPB, Universite de Bordeaux, INRIA & CNRS
  **
  ** This file is part of the Scotch software package for static mapping,
  ** graph partitioning and sparse matrix ordering.
  **
  ** This software is governed by the CeCILL-C license under French law
  ** and abiding by the rules of distribution of free software. You can
  ** use, modify and/or redistribute the software under the terms of the
  ** CeCILL-C license as circulated by CEA, CNRS and INRIA at the following
  ** URL: "http://www.cecill.info".
  ** 
  ** As a counterpart to the access to the source code and rights to copy,
  ** modify and redistribute granted by the license, users are provided
  ** only with a limited warranty and the software's author, the holder of
  ** the economic rights, and the successive licensors have only limited
  ** liability.
  ** 
  ** In this respect, the user's attention is drawn to the risks associated
  ** with loading, using, modifying and/or developing or reproducing the
  ** software by the user in light of its specific status of free software,
  ** that may mean that it is complicated to manipulate, and that also
  ** therefore means that it is reserved for developers and experienced
  ** professionals having in-depth computer knowledge. Users are therefore
  ** encouraged to load and test the software's suitability as regards
  ** their requirements in conditions enabling the security of their
  ** systems and/or data to be ensured and, more generally, to use and
  ** operate it in the same conditions as regards security.
  ** 
  ** The fact that you are presently reading this means that you have had
  ** knowledge of the CeCILL-C license and that you accept its terms.
  */
  /************************************************************/
  /**                                                        **/
  /**   NAME       : bgraph_bipart_st.c                      **/
  /**                                                        **/
  /**   AUTHOR     : Francois PELLEGRINI                     **/
  /**                Sebastien FOURESTIER (v6.0)             **/
  /**                                                        **/
  /**   FUNCTION   : This module contains the strategy and   **/
  /**                method tables for graph bipartitioning  **/
  /**                methods.                                **/
  /**                                                        **/
  /**   DATES      : # Version 3.2  : from : 08 oct 1996     **/
  /**                                 to     13 sep 1998     **/
  /**                # Version 3.3  : from : 01 oct 1998     **/
  /**                                 to     12 mar 1999     **/
  /**                # Version 3.4  : from : 01 jun 2001     **/
  /**                                 to     01 jun 2001     **/
  /**                # Version 4.0  : from : 12 jan 2004     **/
  /**                                 to     20 aug 2004     **/
  /**                # Version 5.0  : from : 27 nov 2006     **/
  /**                                 to     29 may 2007     **/
  /**                # Version 5.1  : from : 26 oct 2009     **/
  /**                                 to     15 apr 2011     **/
  /**                # Version 6.0  : from : 23 fev 2011     **/
  /**                                 to     19 nov 2012     **/
  /**                                                        **/
  /************************************************************/
  
  /*
  **  The defines and includes.
  */
  
  #define BGRAPH_BIPART_ST
  
  #include "module.h"
  #include "common.h"
  #include "fibo.h"
  #include "gain.h"
  #include "parser.h"
  #include "graph.h"
  #include "arch.h"
  #include "mapping.h"
  #include "graph_coarsen.h"
  #include "bgraph.h"
  #include "bgraph_bipart_bd.h"
  #include "bgraph_bipart_df.h"
  #include "bgraph_bipart_ex.h"
  #include "bgraph_bipart_fm.h"
  #include "bgraph_bipart_gg.h"
  #include "bgraph_bipart_gp.h"
  #include "bgraph_bipart_ml.h"
  #include "bgraph_bipart_zr.h"
  #include "bgraph_bipart_st.h"
  
  /*
  **  The static and global variables.
  */
  
  static Bgraph               bgraphdummy;      /*+ Dummy active graph for offset computations +*/
  
  static union {
    BgraphBipartBdParam       param;
    StratNodeMethodData       padding;
  } bgraphbipartstdefaultbd = { { 3, &stratdummy } };
  
  static union {
    BgraphBipartDfParam       param;
    StratNodeMethodData       padding;
  } bgraphbipartstdefaultdf = { { 40, BGRAPHBIPARTDFTYPEBAL } };
  
  static union {                                /* Default parameters for bipartitioning methods */
    BgraphBipartFmParam       param;            /* Parameter zone                                */
    StratNodeMethodData       padding;          /* To avoid reading out of structure             */
  } bgraphbipartstdefaultfm = { { 80, ~0, 0.01L, BGRAPHBIPARTFMTYPEBOUNDARY } };
  
  static union {
    BgraphBipartGgParam       param;
    StratNodeMethodData       padding;
  } bgraphbipartstdefaultgg = { { 5 } };
  
  static union {
    BgraphBipartGpParam       param;
    StratNodeMethodData       padding;
  } bgraphbipartstdefaultgp = { { 5 } };
  
  static union {
    BgraphBipartMlParam       param;
    StratNodeMethodData       padding;
  } bgraphbipartstdefaultml = { { 100, 0.8L, &stratdummy, &stratdummy } };
  
  static StratMethodTab       bgraphbipartstmethtab[] = { /* Bipartitioning methods array */
                                { BGRAPHBIPARTSTMETHBD, "b",  bgraphBipartBd, &bgraphbipartstdefaultbd },
                                { BGRAPHBIPARTSTMETHDF, "d",  bgraphBipartDf, &bgraphbipartstdefaultdf },
                                { BGRAPHBIPARTSTMETHEX, "x",  bgraphBipartEx, NULL },
                                { BGRAPHBIPARTSTMETHFM, "f",  bgraphBipartFm, &bgraphbipartstdefaultfm },
                                { BGRAPHBIPARTSTMETHGG, "h",  bgraphBipartGg, &bgraphbipartstdefaultgg },
                                { BGRAPHBIPARTSTMETHGP, "g",  bgraphBipartGp, &bgraphbipartstdefaultgp },
                                { BGRAPHBIPARTSTMETHML, "m",  bgraphBipartMl, &bgraphbipartstdefaultml },
                                { BGRAPHBIPARTSTMETHZR, "z",  bgraphBipartZr, NULL },
                                { -1,                   NULL, NULL,           NULL } };
  
  static StratParamTab        bgraphbipartstparatab[] = { /* Method parameter list */
                                { BGRAPHBIPARTSTMETHBD,  STRATPARAMSTRAT,  "bnd",
                                  (byte *) &bgraphbipartstdefaultbd.param,
                                  (byte *) &bgraphbipartstdefaultbd.param.stratbnd,
                                  (void *) &bgraphbipartststratab },
                                { BGRAPHBIPARTSTMETHBD,  STRATPARAMSTRAT,  "org",
                                  (byte *) &bgraphbipartstdefaultbd.param,
                                  (byte *) &bgraphbipartstdefaultbd.param.stratorg,
                                  (void *) &bgraphbipartststratab },
                                { BGRAPHBIPARTSTMETHBD,  STRATPARAMINT,    "width",
                                  (byte *) &bgraphbipartstdefaultbd.param,
                                  (byte *) &bgraphbipartstdefaultbd.param.distmax,
                                  NULL },
                                { BGRAPHBIPARTSTMETHDF,  STRATPARAMINT,    "pass",
                                  (byte *) &bgraphbipartstdefaultdf.param,
                                  (byte *) &bgraphbipartstdefaultdf.param.passnbr,
                                  NULL },
                                { BGRAPHBIPARTSTMETHDF,  STRATPARAMCASE,   "type",
                                  (byte *) &bgraphbipartstdefaultdf.param,
                                  (byte *) &bgraphbipartstdefaultdf.param.typeval,
                                  (void *) "bk" },
                                { BGRAPHBIPARTSTMETHFM,  STRATPARAMINT,    "move",
                                  (byte *) &bgraphbipartstdefaultfm.param,
                                  (byte *) &bgraphbipartstdefaultfm.param.movenbr,
                                  NULL },
                                { BGRAPHBIPARTSTMETHFM,  STRATPARAMINT,    "pass",
                                  (byte *) &bgraphbipartstdefaultfm.param,
                                  (byte *) &bgraphbipartstdefaultfm.param.passnbr,
                                  NULL },
                                { BGRAPHBIPARTSTMETHFM,  STRATPARAMDOUBLE, "bal",
                                  (byte *) &bgraphbipartstdefaultfm.param,
                                  (byte *) &bgraphbipartstdefaultfm.param.deltval,
                                  NULL },
                                { BGRAPHBIPARTSTMETHFM,  STRATPARAMCASE,   "type",
                                  (byte *) &bgraphbipartstdefaultfm.param,
                                  (byte *) &bgraphbipartstdefaultfm.param.typeval,
                                  (void *) "ab" },
                                { BGRAPHBIPARTSTMETHGG,  STRATPARAMINT,    "pass",
                                  (byte *) &bgraphbipartstdefaultgg.param,
                                  (byte *) &bgraphbipartstdefaultgg.param.passnbr,
                                  NULL },
                                { BGRAPHBIPARTSTMETHML,  STRATPARAMSTRAT,  "asc",
                                  (byte *) &bgraphbipartstdefaultml.param,
                                  (byte *) &bgraphbipartstdefaultml.param.stratasc,
                                  (void *) &bgraphbipartststratab },
                                { BGRAPHBIPARTSTMETHML,  STRATPARAMSTRAT,  "low",
                                  (byte *) &bgraphbipartstdefaultml.param,
                                  (byte *) &bgraphbipartstdefaultml.param.stratlow,
                                  (void *) &bgraphbipartststratab },
                                { BGRAPHBIPARTSTMETHML,  STRATPARAMINT,    "vert",
                                  (byte *) &bgraphbipartstdefaultml.param,
                                  (byte *) &bgraphbipartstdefaultml.param.coarnbr,
                                  NULL },
                                { BGRAPHBIPARTSTMETHML,  STRATPARAMDOUBLE, "rat",
                                  (byte *) &bgraphbipartstdefaultml.param,
                                  (byte *) &bgraphbipartstdefaultml.param.coarrat,
                                  NULL },
                                { BGRAPHBIPARTSTMETHNBR, STRATPARAMINT,    NULL,
                                  NULL, NULL, NULL } };
  
  static StratParamTab        bgraphbipartstcondtab[] = { /* Active graph condition parameter table */
                                { STRATNODECOND,       STRATPARAMDOUBLE, "bal",
                                  (byte *) &bgraphdummy,
                                  (byte *) &bgraphdummy.bbalval,
                                  NULL },
                                { STRATNODECOND,       STRATPARAMINT,    "edge",
                                  (byte *) &bgraphdummy,
                                  (byte *) &bgraphdummy.s.edgenbr,
                                  NULL },
                                { STRATNODECOND,       STRATPARAMINT,    "levl",
                                  (byte *) &bgraphdummy,
                                  (byte *) &bgraphdummy.levlnum,
                                  NULL },
                                { STRATNODECOND,       STRATPARAMINT,    "lmin0",
                                  (byte *) &bgraphdummy,
                                  (byte *) &bgraphdummy.compload0min,
                                  NULL },
                                { STRATNODECOND,       STRATPARAMINT,    "lmax0",
                                  (byte *) &bgraphdummy,
                                  (byte *) &bgraphdummy.compload0max,
                                  NULL },
                                { STRATNODECOND,       STRATPARAMINT,    "load",
                                  (byte *) &bgraphdummy,
                                  (byte *) &bgraphdummy.s.velosum,
                                  NULL },
                                { STRATNODECOND,       STRATPARAMINT,    "load0",
                                  (byte *) &bgraphdummy,
                                  (byte *) &bgraphdummy.compload0,
                                  NULL },
                                { STRATNODECOND,       STRATPARAMINT,    "vert",
                                  (byte *) &bgraphdummy,
                                  (byte *) &bgraphdummy.s.vertnbr,
                                  NULL },
                                { STRATNODENBR,        STRATPARAMINT,    NULL,
                                  NULL, NULL, NULL } };
  
  StratTab                    bgraphbipartststratab = { /* Strategy tables for graph bipartitioning methods */
                                bgraphbipartstmethtab,
                                bgraphbipartstparatab,
                                bgraphbipartstcondtab };
  
  /***********************************************/
  /*                                             */
  /* This is the generic bipartitioning routine. */
  /*                                             */
  /***********************************************/
  
  /* This routine performs the bipartitioning of
  ** the given active graph according to the
  ** given strategy.
  ** It returns:
  ** - 0 : if bipartitioning could be computed.
  ** - 1 : on error.
  */
  
  int
  bgraphBipartSt (
  Bgraph * restrict const       grafptr,            /*+ Active graph to bipartition +*/
  const Strat * restrict const  strat)              /*+ Bipartitioning strategy     +*/
  {
    StratTest           val;                        /* Result of condition evaluation */
    BgraphStore         savetab[2];                 /* Results of the two strategies  */
    int                 o;
    int                 o2;
  
  #ifdef SCOTCH_DEBUG_BGRAPH2
    if (sizeof (Gnum) != sizeof (INT)) {
      errorPrint ("bgraphBipartSt: invalid type specification for parser variables");
      return     (1);
    }
    if ((sizeof (BgraphBipartFmParam) > sizeof (StratNodeMethodData)) ||
        (sizeof (BgraphBipartGgParam) > sizeof (StratNodeMethodData)) ||
        (sizeof (BgraphBipartMlParam) > sizeof (StratNodeMethodData))) {
      errorPrint ("bgraphBipartSt: invalid type specification");
      return     (1);
    }
  #endif /* SCOTCH_DEBUG_BGRAPH2 */
  #ifdef SCOTCH_DEBUG_BGRAPH1
    if (strat->tabl != &bgraphbipartststratab) {
      errorPrint ("bgraphBipartSt: invalid parameter (1)");
      return     (1);
    }
  #endif /* SCOTCH_DEBUG_BGRAPH1 */
  
    o = 0;
    switch (strat->type) {
      case STRATNODECONCAT :
        o = bgraphBipartSt (grafptr, strat->data.concat.strat[0]); /* Apply the first strategy      */
        if (o == 0)                                 /* If it worked all right                       */
          o |= bgraphBipartSt (grafptr, strat->data.concat.strat[1]); /* Then apply second strategy */
        break;
      case STRATNODECOND :
        o = stratTestEval (strat->data.cond.test, &val, (void *) grafptr); /* Evaluate expression */
        if (o == 0) {                               /* If evaluation was correct                  */
  #ifdef SCOTCH_DEBUG_VGRAPH2
          if ((val.typetest != STRATTESTVAL) ||
              (val.typenode != STRATPARAMLOG)) {
            errorPrint ("bgraphBipartSt: invalid test result");
            o = 1;
            break;
          }
  #endif /* SCOTCH_DEBUG_VGRAPH2 */
          if (val.data.val.vallog == 1)             /* If expression is true                    */
            o = bgraphBipartSt (grafptr, strat->data.cond.strat[0]); /* Apply first strategy    */
          else {                                    /* Else if expression is false              */
            if (strat->data.cond.strat[1] != NULL)  /* And if there is an else statement        */
              o = bgraphBipartSt (grafptr, strat->data.cond.strat[1]); /* Apply second strategy */
          }
        }
        break;
      case STRATNODEEMPTY :
        break;
      case STRATNODESELECT :
        if (((bgraphStoreInit (grafptr, &savetab[0])) != 0) || /* Allocate save areas */
            ((bgraphStoreInit (grafptr, &savetab[1])) != 0)) {
          errorPrint ("bgraphBipartSt: out of memory");
          bgraphStoreExit (&savetab[0]);
          return          (1);
        }
  
        bgraphStoreSave     (grafptr, &savetab[1]); /* Save initial bipartition              */
        o = bgraphBipartSt  (grafptr, strat->data.select.strat[0]); /* Apply first strategy  */
        bgraphStoreSave     (grafptr, &savetab[0]); /* Save its result                       */
        bgraphStoreUpdt     (grafptr, &savetab[1]); /* Restore initial bipartition           */
        o2 = bgraphBipartSt (grafptr, strat->data.select.strat[1]); /* Apply second strategy */
  
        if ((o == 0) || (o2 == 0)) {                /* If at least one method did bipartition */
          Gnum                compload0;
  	int                 b0;
          int                 b1;
  
          compload0 = grafptr->compload0avg + savetab[0].compload0dlt;
          b0 = ((compload0 < grafptr->compload0min) ||
                (compload0 > grafptr->compload0max)) ? 1 : o;
          compload0 = grafptr->compload0avg + savetab[1].compload0dlt;
          b1 = ((compload0 < grafptr->compload0min) ||
                (compload0 > grafptr->compload0max)) ? 1 : o2;
  
          do {                                      /* Do we want to restore partition 0 ? */
            if (b0 > b1)
              break;
            if (b0 == b1) {                         /* If both are valid or invalid  */
              if (b0 == 0) {                        /* If both are valid             */
                if ( (savetab[0].commload >  grafptr->commload) || /* Compare on cut */
                    ((savetab[0].commload == grafptr->commload) &&
                     (abs (savetab[0].compload0dlt) > abs (grafptr->compload0dlt))))
                  break;
              }
              else {                                /* If both are invalid */
                if ( (abs (savetab[0].compload0dlt) >  abs (grafptr->compload0dlt)) || /* Compare on imbalance */
                    ((abs (savetab[0].compload0dlt) == abs (grafptr->compload0dlt)) &&
                     (savetab[0].commload > grafptr->commload)))
                  break;
              }
            }
  
            bgraphStoreUpdt (grafptr, &savetab[0]); /* Restore its result */
          }  while (0);
        }
        if (o2 < o)                                 /* o = min(o,o2): if one biparts, then bipart */
          o = o2;                                   /* Else if one stops, then stop, else error   */
  
        bgraphStoreExit (&savetab[0]);              /* Free both save areas */
        bgraphStoreExit (&savetab[1]);
        break;
  #ifdef SCOTCH_DEBUG_BGRAPH2
      case STRATNODEMETHOD :
  #else /* SCOTCH_DEBUG_BGRAPH2 */
      default :
  #endif /* SCOTCH_DEBUG_BGRAPH2 */
        return (strat->tabl->methtab[strat->data.method.meth].func (grafptr, (void *) &strat->data.method.data));
  #ifdef SCOTCH_DEBUG_BGRAPH2
      default :
        errorPrint ("bgraphBipartSt: invalid parameter (2)");
        return     (1);
  #endif /* SCOTCH_DEBUG_BGRAPH2 */
    }
    return (o);
  }
  