/*

 * Copyright 2010-2011 INRIA Saclay

 * Copyright 2011      Sven Verdoolaege

 * Copyright 2012-2014 Ecole Normale Superieure

 *

 * Use of this software is governed by the MIT license

 *

 * Written by Sven Verdoolaege, INRIA Saclay - Ile-de-France,

 * Parc Club Orsay Universite, ZAC des vignes, 4 rue Jacques Monod,

 * 91893 Orsay, France

 * and Ecole Normale Superieure, 45 rue d’Ulm, 75230 Paris, France

 */

#include <isl/aff.h>

#include <isl_val_private.h>

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

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

#define xS(TYPE,NAME) struct TYPE ## _ ## NAME

#define S(TYPE,NAME) xS(TYPE,NAME)

#ifdef HAS_TYPE

__isl_give PW *FN(PW,alloc_size)(__isl_take isl_space *dim,

	enum isl_fold type, int n)

#else

__isl_give PW *FN(PW,alloc_size)(__isl_take isl_space *dim, int n)

#endif

{

	isl_ctx *ctx;

	struct PW *pw;

	if (!dim)

		return NULL;

	ctx = isl_space_get_ctx(dim);

	isl_assert(ctx, n >= 0, goto error);

	pw = isl_alloc(ctx, struct PW,

			sizeof(struct PW) + (n - 1) * sizeof(S(PW,piece)));

	if (!pw)

		goto error;

	pw->ref = 1;

#ifdef HAS_TYPE

	pw->type = type;

#endif

	pw->size = n;

	pw->n = 0;

	pw->dim = dim;

	return pw;

error:

	isl_space_free(dim);

	return NULL;

}

#ifdef HAS_TYPE

__isl_give PW *FN(PW,ZERO)(__isl_take isl_space *dim, enum isl_fold type)

{

	return FN(PW,alloc_size)(dim, type, 0);

}

#else

__isl_give PW *FN(PW,ZERO)(__isl_take isl_space *dim)

{

	return FN(PW,alloc_size)(dim, 0);

}

#endif

__isl_give PW *FN(PW,add_piece)(__isl_take PW *pw,

	__isl_take isl_set *set, __isl_take EL *el)

{

	isl_ctx *ctx;

	isl_space *el_dim = NULL;

	if (!pw || !set || !el)

		goto error;

	if (isl_set_plain_is_empty(set) || FN(EL,EL_IS_ZERO)(el)) {

		isl_set_free(set);

		FN(EL,free)(el);

		return pw;

	}

	ctx = isl_set_get_ctx(set);

#ifdef HAS_TYPE

	if (pw->type != el->type)

		isl_die(ctx, isl_error_invalid, "fold types don't match",

			goto error);

#endif

	el_dim = FN(EL,get_space(el));

	isl_assert(ctx, isl_space_is_equal(pw->dim, el_dim), goto error);

	isl_assert(ctx, pw->n < pw->size, goto error);

	pw->p[pw->n].set = set;

	pw->p[pw->n].FIELD = el;

	pw->n++;

	isl_space_free(el_dim);

	return pw;

error:

	isl_space_free(el_dim);

	FN(PW,free)(pw);

	isl_set_free(set);

	FN(EL,free)(el);

	return NULL;

}

#ifdef HAS_TYPE

__isl_give PW *FN(PW,alloc)(enum isl_fold type,

	__isl_take isl_set *set, __isl_take EL *el)

#else

__isl_give PW *FN(PW,alloc)(__isl_take isl_set *set, __isl_take EL *el)

#endif

{

	PW *pw;

	if (!set || !el)

		goto error;

#ifdef HAS_TYPE

	pw = FN(PW,alloc_size)(FN(EL,get_space)(el), type, 1);

#else

	pw = FN(PW,alloc_size)(FN(EL,get_space)(el), 1);

#endif

	return FN(PW,add_piece)(pw, set, el);

error:

	isl_set_free(set);

	FN(EL,free)(el);

	return NULL;

}

__isl_give PW *FN(PW,dup)(__isl_keep PW *pw)

{

	int i;

	PW *dup;

	if (!pw)

		return NULL;

#ifdef HAS_TYPE

	dup = FN(PW,alloc_size)(isl_space_copy(pw->dim), pw->type, pw->n);

#else

	dup = FN(PW,alloc_size)(isl_space_copy(pw->dim), pw->n);

#endif

	if (!dup)

		return NULL;

	for (i = 0; i < pw->n; ++i)

		dup = FN(PW,add_piece)(dup, isl_set_copy(pw->p[i].set),

					    FN(EL,copy)(pw->p[i].FIELD));

	return dup;

}

__isl_give PW *FN(PW,cow)(__isl_take PW *pw)

{

	if (!pw)

		return NULL;

	if (pw->ref == 1)

		return pw;

	pw->ref--;

	return FN(PW,dup)(pw);

}

__isl_give PW *FN(PW,copy)(__isl_keep PW *pw)

{

	if (!pw)

		return NULL;

	pw->ref++;

	return pw;

}

__isl_null PW *FN(PW,free)(__isl_take PW *pw)

{

	int i;

	if (!pw)

		return NULL;

	if (--pw->ref > 0)

		return NULL;

	for (i = 0; i < pw->n; ++i) {

		isl_set_free(pw->p[i].set);

		FN(EL,free)(pw->p[i].FIELD);

	}

	isl_space_free(pw->dim);

	free(pw);

	return NULL;

}

const char *FN(PW,get_dim_name)(__isl_keep PW *pw, enum isl_dim_type type,

	unsigned pos)

{

	return pw ? isl_space_get_dim_name(pw->dim, type, pos) : NULL;

}

isl_bool FN(PW,has_dim_id)(__isl_keep PW *pw, enum isl_dim_type type,

	unsigned pos)

{

	return pw ? isl_space_has_dim_id(pw->dim, type, pos) : isl_bool_error;

}

__isl_give isl_id *FN(PW,get_dim_id)(__isl_keep PW *pw, enum isl_dim_type type,

	unsigned pos)

{

	return pw ? isl_space_get_dim_id(pw->dim, type, pos) : NULL;

}

isl_bool FN(PW,has_tuple_name)(__isl_keep PW *pw, enum isl_dim_type type)

{

	return pw ? isl_space_has_tuple_name(pw->dim, type) : isl_bool_error;

}

const char *FN(PW,get_tuple_name)(__isl_keep PW *pw, enum isl_dim_type type)

{

	return pw ? isl_space_get_tuple_name(pw->dim, type) : NULL;

}

isl_bool FN(PW,has_tuple_id)(__isl_keep PW *pw, enum isl_dim_type type)

{

	return pw ? isl_space_has_tuple_id(pw->dim, type) : isl_bool_error;

}

__isl_give isl_id *FN(PW,get_tuple_id)(__isl_keep PW *pw, enum isl_dim_type type)

{

	return pw ? isl_space_get_tuple_id(pw->dim, type) : NULL;

}

isl_bool FN(PW,IS_ZERO)(__isl_keep PW *pw)

{

	if (!pw)

		return isl_bool_error;

	return pw->n == 0;

}

#ifndef NO_REALIGN

__isl_give PW *FN(PW,realign_domain)(__isl_take PW *pw,

	__isl_take isl_reordering *exp)

{

	int i;

	pw = FN(PW,cow)(pw);

	if (!pw || !exp)

		goto error;

	for (i = 0; i < pw->n; ++i) {

		pw->p[i].set = isl_set_realign(pw->p[i].set,

						    isl_reordering_copy(exp));

		if (!pw->p[i].set)

			goto error;

		pw->p[i].FIELD = FN(EL,realign_domain)(pw->p[i].FIELD,

						    isl_reordering_copy(exp));

		if (!pw->p[i].FIELD)

			goto error;

	}

	pw = FN(PW,reset_domain_space)(pw, isl_space_copy(exp->dim));

	isl_reordering_free(exp);

	return pw;

error:

	isl_reordering_free(exp);

	FN(PW,free)(pw);

	return NULL;

}

/* Align the parameters of "pw" to those of "model".

 */

__isl_give PW *FN(PW,align_params)(__isl_take PW *pw, __isl_take isl_space *model)

{

	isl_ctx *ctx;

	if (!pw || !model)

		goto error;

	ctx = isl_space_get_ctx(model);

	if (!isl_space_has_named_params(model))

		isl_die(ctx, isl_error_invalid,

			"model has unnamed parameters", goto error);

	if (!isl_space_has_named_params(pw->dim))

		isl_die(ctx, isl_error_invalid,

			"input has unnamed parameters", goto error);

	if (!isl_space_match(pw->dim, isl_dim_param, model, isl_dim_param)) {

		isl_reordering *exp;

		model = isl_space_drop_dims(model, isl_dim_in,

					0, isl_space_dim(model, isl_dim_in));

		model = isl_space_drop_dims(model, isl_dim_out,

					0, isl_space_dim(model, isl_dim_out));

		exp = isl_parameter_alignment_reordering(pw->dim, model);

		exp = isl_reordering_extend_space(exp,

					FN(PW,get_domain_space)(pw));

		pw = FN(PW,realign_domain)(pw, exp);

	}

	isl_space_free(model);

	return pw;

error:

	isl_space_free(model);

	FN(PW,free)(pw);

	return NULL;

}

static __isl_give PW *FN(PW,align_params_pw_pw_and)(__isl_take PW *pw1,

	__isl_take PW *pw2,

	__isl_give PW *(*fn)(__isl_take PW *pw1, __isl_take PW *pw2))

{

	isl_ctx *ctx;

	if (!pw1 || !pw2)

		goto error;

	if (isl_space_match(pw1->dim, isl_dim_param, pw2->dim, isl_dim_param))

		return fn(pw1, pw2);

	ctx = FN(PW,get_ctx)(pw1);

	if (!isl_space_has_named_params(pw1->dim) ||

	    !isl_space_has_named_params(pw2->dim))

		isl_die(ctx, isl_error_invalid,

			"unaligned unnamed parameters", goto error);

	pw1 = FN(PW,align_params)(pw1, FN(PW,get_space)(pw2));

	pw2 = FN(PW,align_params)(pw2, FN(PW,get_space)(pw1));

	return fn(pw1, pw2);

error:

	FN(PW,free)(pw1);

	FN(PW,free)(pw2);

	return NULL;

}

static __isl_give PW *FN(PW,align_params_pw_set_and)(__isl_take PW *pw,

	__isl_take isl_set *set,

	__isl_give PW *(*fn)(__isl_take PW *pw, __isl_take isl_set *set))

{

	isl_ctx *ctx;

	if (!pw || !set)

		goto error;

	if (isl_space_match(pw->dim, isl_dim_param, set->dim, isl_dim_param))

		return fn(pw, set);

	ctx = FN(PW,get_ctx)(pw);

	if (!isl_space_has_named_params(pw->dim) ||

	    !isl_space_has_named_params(set->dim))

		isl_die(ctx, isl_error_invalid,

			"unaligned unnamed parameters", goto error);

	pw = FN(PW,align_params)(pw, isl_set_get_space(set));

	set = isl_set_align_params(set, FN(PW,get_space)(pw));

	return fn(pw, set);

error:

	FN(PW,free)(pw);

	isl_set_free(set);

	return NULL;

}

#endif

static __isl_give PW *FN(PW,union_add_aligned)(__isl_take PW *pw1,

	__isl_take PW *pw2)

{

	int i, j, n;

	struct PW *res;

	isl_ctx *ctx;

	isl_set *set;

	if (!pw1 || !pw2)

		goto error;

	ctx = isl_space_get_ctx(pw1->dim);

#ifdef HAS_TYPE

	if (pw1->type != pw2->type)

		isl_die(ctx, isl_error_invalid,

			"fold types don't match", goto error);

#endif

	isl_assert(ctx, isl_space_is_equal(pw1->dim, pw2->dim), goto error);

	if (FN(PW,IS_ZERO)(pw1)) {

		FN(PW,free)(pw1);

		return pw2;

	}

	if (FN(PW,IS_ZERO)(pw2)) {

		FN(PW,free)(pw2);

		return pw1;

	}

	n = (pw1->n + 1) * (pw2->n + 1);

#ifdef HAS_TYPE

	res = FN(PW,alloc_size)(isl_space_copy(pw1->dim), pw1->type, n);

#else

	res = FN(PW,alloc_size)(isl_space_copy(pw1->dim), n);

#endif

	for (i = 0; i < pw1->n; ++i) {

		set = isl_set_copy(pw1->p[i].set);

		for (j = 0; j < pw2->n; ++j) {

			struct isl_set *common;

			EL *sum;

			common = isl_set_intersect(isl_set_copy(pw1->p[i].set),

						isl_set_copy(pw2->p[j].set));

			if (isl_set_plain_is_empty(common)) {

				isl_set_free(common);

				continue;

			}

			set = isl_set_subtract(set,

					isl_set_copy(pw2->p[j].set));

			sum = FN(EL,add_on_domain)(common,

						   FN(EL,copy)(pw1->p[i].FIELD),

						   FN(EL,copy)(pw2->p[j].FIELD));

			res = FN(PW,add_piece)(res, common, sum);

		}

		res = FN(PW,add_piece)(res, set, FN(EL,copy)(pw1->p[i].FIELD));

	}

	for (j = 0; j < pw2->n; ++j) {

		set = isl_set_copy(pw2->p[j].set);

		for (i = 0; i < pw1->n; ++i)

			set = isl_set_subtract(set,

					isl_set_copy(pw1->p[i].set));

		res = FN(PW,add_piece)(res, set, FN(EL,copy)(pw2->p[j].FIELD));

	}

	FN(PW,free)(pw1);

	FN(PW,free)(pw2);

	return res;

error:

	FN(PW,free)(pw1);

	FN(PW,free)(pw2);

	return NULL;

}

/* Private version of "union_add".  For isl_pw_qpolynomial and

 * isl_pw_qpolynomial_fold, we prefer to simply call it "add".

 */

static __isl_give PW *FN(PW,union_add_)(__isl_take PW *pw1, __isl_take PW *pw2)

{

	return FN(PW,align_params_pw_pw_and)(pw1, pw2,

						&FN(PW,union_add_aligned));

}

/* Make sure "pw" has room for at least "n" more pieces.

 *

 * If there is only one reference to pw, we extend it in place.

 * Otherwise, we create a new PW and copy the pieces.

 */

static __isl_give PW *FN(PW,grow)(__isl_take PW *pw, int n)

{

	int i;

	isl_ctx *ctx;

	PW *res;

	if (!pw)

		return NULL;

	if (pw->n + n <= pw->size)

		return pw;

	ctx = FN(PW,get_ctx)(pw);

	n += pw->n;

	if (pw->ref == 1) {

		res = isl_realloc(ctx, pw, struct PW,

			    sizeof(struct PW) + (n - 1) * sizeof(S(PW,piece)));

		if (!res)

			return FN(PW,free)(pw);

		res->size = n;

		return res;

	}

#ifdef HAS_TYPE

	res = FN(PW,alloc_size)(isl_space_copy(pw->dim), pw->type, n);

#else

	res = FN(PW,alloc_size)(isl_space_copy(pw->dim), n);

#endif

	if (!res)

		return FN(PW,free)(pw);

	for (i = 0; i < pw->n; ++i)

		res = FN(PW,add_piece)(res, isl_set_copy(pw->p[i].set),

					    FN(EL,copy)(pw->p[i].FIELD));

	FN(PW,free)(pw);

	return res;

}

static __isl_give PW *FN(PW,add_disjoint_aligned)(__isl_take PW *pw1,

	__isl_take PW *pw2)

{

	int i;

	isl_ctx *ctx;

	if (!pw1 || !pw2)

		goto error;

	if (pw1->size < pw1->n + pw2->n && pw1->n < pw2->n)

		return FN(PW,add_disjoint_aligned)(pw2, pw1);

	ctx = isl_space_get_ctx(pw1->dim);

#ifdef HAS_TYPE

	if (pw1->type != pw2->type)

		isl_die(ctx, isl_error_invalid,

			"fold types don't match", goto error);

#endif

	isl_assert(ctx, isl_space_is_equal(pw1->dim, pw2->dim), goto error);

	if (FN(PW,IS_ZERO)(pw1)) {

		FN(PW,free)(pw1);

		return pw2;

	}

	if (FN(PW,IS_ZERO)(pw2)) {

		FN(PW,free)(pw2);

		return pw1;

	}

	pw1 = FN(PW,grow)(pw1, pw2->n);

	if (!pw1)

		goto error;

	for (i = 0; i < pw2->n; ++i)

		pw1 = FN(PW,add_piece)(pw1,

				isl_set_copy(pw2->p[i].set),

				FN(EL,copy)(pw2->p[i].FIELD));

	FN(PW,free)(pw2);

	return pw1;

error:

	FN(PW,free)(pw1);

	FN(PW,free)(pw2);

	return NULL;

}

__isl_give PW *FN(PW,add_disjoint)(__isl_take PW *pw1, __isl_take PW *pw2)

{

	return FN(PW,align_params_pw_pw_and)(pw1, pw2,

						&FN(PW,add_disjoint_aligned));

}

/* This function is currently only used from isl_aff.c

 */

static __isl_give PW *FN(PW,on_shared_domain_in)(__isl_take PW *pw1,

	__isl_take PW *pw2, __isl_take isl_space *space,

	__isl_give EL *(*fn)(__isl_take EL *el1, __isl_take EL *el2))

	__attribute__ ((unused));

/* Apply "fn" to pairs of elements from pw1 and pw2 on shared domains.

 * The result of "fn" (and therefore also of this function) lives in "space".

 */

static __isl_give PW *FN(PW,on_shared_domain_in)(__isl_take PW *pw1,

	__isl_take PW *pw2, __isl_take isl_space *space,

	__isl_give EL *(*fn)(__isl_take EL *el1, __isl_take EL *el2))

{

	int i, j, n;

	PW *res = NULL;

	if (!pw1 || !pw2)

		goto error;

	n = pw1->n * pw2->n;

#ifdef HAS_TYPE

	res = FN(PW,alloc_size)(isl_space_copy(space), pw1->type, n);

#else

	res = FN(PW,alloc_size)(isl_space_copy(space), n);

#endif

	for (i = 0; i < pw1->n; ++i) {

		for (j = 0; j < pw2->n; ++j) {

			isl_set *common;

			EL *res_ij;

			int empty;

			common = isl_set_intersect(

					isl_set_copy(pw1->p[i].set),

					isl_set_copy(pw2->p[j].set));

			empty = isl_set_plain_is_empty(common);

			if (empty < 0 || empty) {

				isl_set_free(common);

				if (empty < 0)

					goto error;

				continue;

			}

			res_ij = fn(FN(EL,copy)(pw1->p[i].FIELD),

				    FN(EL,copy)(pw2->p[j].FIELD));

			res_ij = FN(EL,gist)(res_ij, isl_set_copy(common));

			res = FN(PW,add_piece)(res, common, res_ij);

		}

	}

	isl_space_free(space);

	FN(PW,free)(pw1);

	FN(PW,free)(pw2);

	return res;

error:

	isl_space_free(space);

	FN(PW,free)(pw1);

	FN(PW,free)(pw2);

	FN(PW,free)(res);

	return NULL;

}

/* This function is currently only used from isl_aff.c

 */

static __isl_give PW *FN(PW,on_shared_domain)(__isl_take PW *pw1,

	__isl_take PW *pw2,

	__isl_give EL *(*fn)(__isl_take EL *el1, __isl_take EL *el2))

	__attribute__ ((unused));

/* Apply "fn" to pairs of elements from pw1 and pw2 on shared domains.

 * The result of "fn" is assumed to live in the same space as "pw1" and "pw2".

 */

static __isl_give PW *FN(PW,on_shared_domain)(__isl_take PW *pw1,

	__isl_take PW *pw2,

	__isl_give EL *(*fn)(__isl_take EL *el1, __isl_take EL *el2))

{

	isl_space *space;

	if (!pw1 || !pw2)

		goto error;

	space = isl_space_copy(pw1->dim);

	return FN(PW,on_shared_domain_in)(pw1, pw2, space, fn);

error:

	FN(PW,free)(pw1);

	FN(PW,free)(pw2);

	return NULL;

}

#ifndef NO_NEG

__isl_give PW *FN(PW,neg)(__isl_take PW *pw)

{

	int i;

	if (!pw)

		return NULL;

	if (FN(PW,IS_ZERO)(pw))

		return pw;

	pw = FN(PW,cow)(pw);

	if (!pw)

		return NULL;

	for (i = 0; i < pw->n; ++i) {

		pw->p[i].FIELD = FN(EL,neg)(pw->p[i].FIELD);

		if (!pw->p[i].FIELD)

			return FN(PW,free)(pw);

	}

	return pw;

}

#endif

#ifndef NO_SUB

__isl_give PW *FN(PW,sub)(__isl_take PW *pw1, __isl_take PW *pw2)

{

	return FN(PW,add)(pw1, FN(PW,neg)(pw2));

}

#endif

#ifndef NO_EVAL

__isl_give isl_val *FN(PW,eval)(__isl_take PW *pw, __isl_take isl_point *pnt)

{

	int i;

	int found = 0;

	isl_ctx *ctx;

	isl_space *pnt_dim = NULL;

	isl_val *v;

	if (!pw || !pnt)

		goto error;

	ctx = isl_point_get_ctx(pnt);

	pnt_dim = isl_point_get_space(pnt);

	isl_assert(ctx, isl_space_is_domain_internal(pnt_dim, pw->dim),

		    goto error);

	for (i = 0; i < pw->n; ++i) {

		found = isl_set_contains_point(pw->p[i].set, pnt);

		if (found < 0)

			goto error;

		if (found)

			break;

	}

	if (found)

		v = FN(EL,eval)(FN(EL,copy)(pw->p[i].FIELD),

					    isl_point_copy(pnt));

	else

		v = isl_val_zero(ctx);

	FN(PW,free)(pw);

	isl_space_free(pnt_dim);

	isl_point_free(pnt);

	return v;

error:

	FN(PW,free)(pw);

	isl_space_free(pnt_dim);

	isl_point_free(pnt);

	return NULL;

}

#endif

/* Return the parameter domain of "pw".

 */

__isl_give isl_set *FN(PW,params)(__isl_take PW *pw)

{

	return isl_set_params(FN(PW,domain)(pw));

}

__isl_give isl_set *FN(PW,domain)(__isl_take PW *pw)

{

	int i;

	isl_set *dom;

	if (!pw)

		return NULL;

	dom = isl_set_empty(FN(PW,get_domain_space)(pw));

	for (i = 0; i < pw->n; ++i)

		dom = isl_set_union_disjoint(dom, isl_set_copy(pw->p[i].set));

	FN(PW,free)(pw);

	return dom;

}

/* Exploit the equalities in the domain of piece "i" of "pw"

 * to simplify the associated function.

 * If the domain of piece "i" is empty, then remove it entirely,

 * replacing it with the final piece.

 */

static int FN(PW,exploit_equalities_and_remove_if_empty)(__isl_keep PW *pw,

	int i)

{

	isl_basic_set *aff;

	int empty = isl_set_plain_is_empty(pw->p[i].set);

	if (empty < 0)

		return -1;

	if (empty) {

		isl_set_free(pw->p[i].set);

		FN(EL,free)(pw->p[i].FIELD);

		if (i != pw->n - 1)

			pw->p[i] = pw->p[pw->n - 1];

		pw->n--;

		return 0;

	}

	aff = isl_set_affine_hull(isl_set_copy(pw->p[i].set));

	pw->p[i].FIELD = FN(EL,substitute_equalities)(pw->p[i].FIELD, aff);

	if (!pw->p[i].FIELD)

		return -1;

	return 0;

}

/* Convert a piecewise expression defined over a parameter domain

 * into one that is defined over a zero-dimensional set.

 */

__isl_give PW *FN(PW,from_range)(__isl_take PW *pw)

{

	isl_space *space;

	if (!pw)

		return NULL;

	if (!isl_space_is_set(pw->dim))

		isl_die(FN(PW,get_ctx)(pw), isl_error_invalid,

			"not living in a set space", return FN(PW,free)(pw));

	space = FN(PW,get_space)(pw);

	space = isl_space_from_range(space);

	pw = FN(PW,reset_space)(pw, space);

	return pw;

}

/* Fix the value of the given parameter or domain dimension of "pw"

 * to be equal to "value".

 */

__isl_give PW *FN(PW,fix_si)(__isl_take PW *pw, enum isl_dim_type type,

	unsigned pos, int value)

{

	int i;

	if (!pw)

		return NULL;

	if (type == isl_dim_out)

		isl_die(FN(PW,get_ctx)(pw), isl_error_invalid,

			"cannot fix output dimension", return FN(PW,free)(pw));

	if (pw->n == 0)

		return pw;

	if (type == isl_dim_in)

		type = isl_dim_set;

	pw = FN(PW,cow)(pw);

	if (!pw)

		return FN(PW,free)(pw);

	for (i = pw->n - 1; i >= 0; --i) {

		pw->p[i].set = isl_set_fix_si(pw->p[i].set, type, pos, value);

		if (FN(PW,exploit_equalities_and_remove_if_empty)(pw, i) < 0)

			return FN(PW,free)(pw);

	}

	return pw;

}

/* Restrict the domain of "pw" by combining each cell

 * with "set" through a call to "fn", where "fn" may be

 * isl_set_intersect, isl_set_intersect_params or isl_set_subtract.

 */

static __isl_give PW *FN(PW,restrict_domain_aligned)(__isl_take PW *pw,

	__isl_take isl_set *set,

	__isl_give isl_set *(*fn)(__isl_take isl_set *set1,

				    __isl_take isl_set *set2))

{

	int i;

	if (!pw || !set)

		goto error;

	if (pw->n == 0) {

		isl_set_free(set);

		return pw;

	}

	pw = FN(PW,cow)(pw);

	if (!pw)

		goto error;

	for (i = pw->n - 1; i >= 0; --i) {

		pw->p[i].set = fn(pw->p[i].set, isl_set_copy(set));

		if (FN(PW,exploit_equalities_and_remove_if_empty)(pw, i) < 0)

			goto error;

	}

	isl_set_free(set);

	return pw;

error:

	isl_set_free(set);

	FN(PW,free)(pw);

	return NULL;

}

static __isl_give PW *FN(PW,intersect_domain_aligned)(__isl_take PW *pw,

	__isl_take isl_set *set)

{

	return FN(PW,restrict_domain_aligned)(pw, set, &isl_set_intersect);

}

__isl_give PW *FN(PW,intersect_domain)(__isl_take PW *pw,

	__isl_take isl_set *context)

{

	return FN(PW,align_params_pw_set_and)(pw, context,

					&FN(PW,intersect_domain_aligned));

}

static __isl_give PW *FN(PW,intersect_params_aligned)(__isl_take PW *pw,

	__isl_take isl_set *set)

{

	return FN(PW,restrict_domain_aligned)(pw, set,

					&isl_set_intersect_params);

}

/* Intersect the domain of "pw" with the parameter domain "context".

 */

__isl_give PW *FN(PW,intersect_params)(__isl_take PW *pw,

	__isl_take isl_set *context)

{

	return FN(PW,align_params_pw_set_and)(pw, context,

					&FN(PW,intersect_params_aligned));

}

/* Subtract "domain' from the domain of "pw", assuming their

 * parameters have been aligned.

 */

static __isl_give PW *FN(PW,subtract_domain_aligned)(__isl_take PW *pw,

	__isl_take isl_set *domain)

{

	return FN(PW,restrict_domain_aligned)(pw, domain, &isl_set_subtract);

}