reduce_domain.c

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