isl_power_templ.c

   1 #define xFN(TYPE,NAME) TYPE ## _ ## NAME
   2 #define FN(TYPE,NAME) xFN(TYPE,NAME)
   3
   4 /* Compute the given non-zero power of "map" and return the result.
   5  * If the exponent "exp" is negative, then the -exp th power of the inverse
   6  * relation is computed.
   7  */
   8 __isl_give TYPE *FN(TYPE,fixed_power)(__isl_take TYPE *map, isl_int exp)
   9 {
  10         isl_ctx *ctx;
  11         TYPE *res = NULL;
  12         isl_int r;
  13
  14         if (!map)
  15                 return NULL;
  16
  17         ctx = FN(TYPE,get_ctx)(map);
  18         if (isl_int_is_zero(exp))
  19                 isl_die(ctx, isl_error_invalid,
  20                         "expecting non-zero exponent", goto error);
  21
  22         if (isl_int_is_neg(exp)) {
  23                 isl_int_neg(exp, exp);
  24                 map = FN(TYPE,reverse)(map);
  25                 return FN(TYPE,fixed_power)(map, exp);
  26         }
  27
  28         isl_int_init(r);
  29         for (;;) {
  30                 isl_int_fdiv_r(r, exp, ctx->two);
  31
  32                 if (!isl_int_is_zero(r)) {
  33                         if (!res)
  34                                 res = FN(TYPE,copy)(map);
  35                         else {
  36                                 res = FN(TYPE,apply_range)(res,
  37                                                           FN(TYPE,copy)(map));
  38                                 res = FN(TYPE,coalesce)(res);
  39                         }
  40                         if (!res)
  41                                 break;
  42                 }
  43
  44                 isl_int_fdiv_q(exp, exp, ctx->two);
  45                 if (isl_int_is_zero(exp))
  46                         break;
  47
  48                 map = FN(TYPE,apply_range)(map, FN(TYPE,copy)(map));
  49                 map = FN(TYPE,coalesce)(map);
  50         }
  51         isl_int_clear(r);
  52
  53         FN(TYPE,free)(map);
  54         return res;
  55 error:
  56         FN(TYPE,free)(map);
  57         return NULL;
  58 }