isl_pw_opt_templ.c

   1 /*
   2  * Copyright 2010      INRIA Saclay
   3  *
   4  * Use of this software is governed by the MIT license
   5  *
   6  * Written by Sven Verdoolaege, INRIA Saclay - Ile-de-France,
   7  * Parc Club Orsay Universite, ZAC des vignes, 4 rue Jacques Monod,
   8  * 91893 Orsay, France
   9  */
  10
  11 /* Compute the maximal value attained by the piecewise quasipolynomial
  12  * on its domain or zero if the domain is empty.
  13  * In the worst case, the domain is scanned completely,
  14  * so the domain is assumed to be bounded.
  15  */
  16 __isl_give isl_val *FN(PW,opt)(__isl_take PW *pw, int max)
  17 {
  18         int i;
  19         isl_val *opt;
  20
  21         if (!pw)
  22                 return NULL;
  23
  24         if (pw->n == 0) {
  25                 opt = isl_val_zero(FN(PW,get_ctx)(pw));
  26                 FN(PW,free)(pw);
  27                 return opt;
  28         }
  29
  30         opt = FN(EL,opt_on_domain)(FN(EL,copy)(pw->p[0].FIELD),
  31                                         isl_set_copy(pw->p[0].set), max);
  32         for (i = 1; i < pw->n; ++i) {
  33                 isl_val *opt_i;
  34                 opt_i = FN(EL,opt_on_domain)(FN(EL,copy)(pw->p[i].FIELD),
  35                                                 isl_set_copy(pw->p[i].set), max);
  36                 if (max)
  37                         opt = isl_val_max(opt, opt_i);
  38                 else
  39                         opt = isl_val_min(opt, opt_i);
  40         }
  41
  42         FN(PW,free)(pw);
  43         return opt;
  44 }
  45
  46 __isl_give isl_val *FN(PW,max)(__isl_take PW *pw)
  47 {
  48         return FN(PW,opt)(pw, 1);
  49 }
  50
  51 __isl_give isl_val *FN(PW,min)(__isl_take PW *pw)
  52 {
  53         return FN(PW,opt)(pw, 0);
  54 }