#include <isl_val_private.h>

#define xFN(TYPE,NAME) TYPE ## _ ## NAME

#define FN(TYPE,NAME) xFN(TYPE,NAME)

/* Compute the given non-zero power of "map" and return the result.

 * If the exponent "exp" is negative, then the -exp th power of the inverse

 * relation is computed.

 */

__isl_give TYPE *FN(TYPE,fixed_power)(__isl_take TYPE *map, isl_int exp)

{

	isl_ctx *ctx;

	TYPE *res = NULL;

	isl_int r;

	if (!map)

		return NULL;

	ctx = FN(TYPE,get_ctx)(map);

	if (isl_int_is_zero(exp))

		isl_die(ctx, isl_error_invalid,

			"expecting non-zero exponent", goto error);

	if (isl_int_is_neg(exp)) {

		isl_int_neg(exp, exp);

		map = FN(TYPE,reverse)(map);

		return FN(TYPE,fixed_power)(map, exp);

	}

	isl_int_init(r);

	for (;;) {

		isl_int_fdiv_r(r, exp, ctx->two);

		if (!isl_int_is_zero(r)) {

			if (!res)

				res = FN(TYPE,copy)(map);

			else {

				res = FN(TYPE,apply_range)(res,

							  FN(TYPE,copy)(map));

				res = FN(TYPE,coalesce)(res);

			}

			if (!res)

				break;

		}

		isl_int_fdiv_q(exp, exp, ctx->two);

		if (isl_int_is_zero(exp))

			break;

		map = FN(TYPE,apply_range)(map, FN(TYPE,copy)(map));

		map = FN(TYPE,coalesce)(map);

	}

	isl_int_clear(r);

	FN(TYPE,free)(map);

	return res;

error:

	FN(TYPE,free)(map);

	return NULL;

}

/* Compute the given non-zero power of "map" and return the result.

 * If the exponent "exp" is negative, then the -exp th power of the inverse

 * relation is computed.

 */

__isl_give TYPE *FN(TYPE,fixed_power_val)(__isl_take TYPE *map,

	__isl_take isl_val *exp)

{

	if (!map || !exp)

		goto error;

	if (!isl_val_is_int(exp))

		isl_die(FN(TYPE,get_ctx)(map), isl_error_invalid,

			"expecting integer exponent", goto error);

	map = FN(TYPE,fixed_power)(map, exp->n);

	isl_val_free(exp);

	return map;

error:

	FN(TYPE,free)(map);

	isl_val_free(exp);

	return NULL;

}