reduce_domain.c

   1 #include <barvinok/options.h>
   2 #include "reduce_domain.h"
   3
   4 Polyhedron *reduce_domain(Polyhedron *D, Matrix *CT, Polyhedron *CEq,
   5                           Polyhedron **fVD, int nd,
   6                           struct barvinok_options *options)
   7 {
   8     Polyhedron *Dt, *rVD;
   9     Polyhedron *C;
  10     Value c;
  11     int i;
  12
  13     C = D->next ? DomainConvex(D, options->MaxRays) : D;
  14     Dt = CT ? DomainPreimage(C, CT, options->MaxRays) : C;
  15     rVD = CEq ? DomainIntersection(Dt, CEq, options->MaxRays) : Domain_Copy(Dt);
  16
  17     /* if rVD is empty or too small in geometric dimension */
  18     if(!rVD || emptyQ(rVD) ||
  19             (CEq && rVD->Dimension-rVD->NbEq < Dt->Dimension-Dt->NbEq-CEq->NbEq)) {
  20         if(rVD)
  21             Domain_Free(rVD);
  22         if (D->next)
  23             Polyhedron_Free(C);
  24         if (CT)
  25             Domain_Free(Dt);
  26         return 0;               /* empty validity domain */
  27     }
  28
  29     if (D->next)
  30         Polyhedron_Free(C);
  31     if (CT)
  32         Domain_Free(Dt);
  33
  34     fVD[nd] = Domain_Copy(rVD);
  35     for (i = 0 ; i < nd; ++i) {
  36         Polyhedron *F;
  37         Polyhedron *I = DomainIntersection(fVD[nd], fVD[i], options->MaxRays);
  38         if (emptyQ(I)) {
  39             Domain_Free(I);
  40             continue;
  41         }
  42         F = DomainSimplify(I, fVD[nd], options->MaxRays);
  43         if (F->NbEq == 1) {
  44             Polyhedron *T = rVD;
  45             rVD = DomainDifference(rVD, F, options->MaxRays);
  46             Domain_Free(T);
  47         }
  48         Domain_Free(F);
  49         Domain_Free(I);
  50     }
  51
  52     rVD = DomainConstraintSimplify(rVD, options->MaxRays);
  53     if (emptyQ(rVD)) {
  54         Domain_Free(fVD[nd]);
  55         Domain_Free(rVD);
  56         return 0;
  57     }
  58
  59     value_init(c);
  60     barvinok_count_with_options(rVD, &c, options);
  61     if (value_zero_p(c)) {
  62         Domain_Free(rVD);
  63         rVD = 0;
  64     }
  65     value_clear(c);
  66
  67     return rVD;
  68 }