/*

 * Copyright 2008-2009 Katholieke Universiteit Leuven

 * Copyright 2010-2011 INRIA Saclay

 *

 * Use of this software is governed by the MIT license

 *

 * Written by Sven Verdoolaege, K.U.Leuven, Departement

 * Computerwetenschappen, Celestijnenlaan 200A, B-3001 Leuven, Belgium

 * and INRIA Saclay - Ile-de-France, Parc Club Orsay Universite,

 * ZAC des vignes, 4 rue Jacques Monod, 91893 Orsay, France 

 */

#include <isl_map_private.h>

#include <isl_space_private.h>

#include <isl_dim_map.h>

#include <isl_reordering.h>

struct isl_dim_map_entry {

	int pos;

	int sgn;

};

/* Maps dst positions to src positions */

struct isl_dim_map {

	unsigned len;

	struct isl_dim_map_entry m[1];

};

__isl_give isl_dim_map *isl_dim_map_alloc(isl_ctx *ctx, unsigned len)

{

	int i;

	struct isl_dim_map *dim_map;

	dim_map = isl_alloc(ctx, struct isl_dim_map,

	    sizeof(struct isl_dim_map) + len * sizeof(struct isl_dim_map_entry));

	if (!dim_map)

		return NULL;

	dim_map->len = 1 + len;

	dim_map->m[0].pos = 0;

	dim_map->m[0].sgn = 1;

	for (i = 0; i < len; ++i)

		dim_map->m[1 + i].sgn = 0;

	return dim_map;

}

void isl_dim_map_range(__isl_keep isl_dim_map *dim_map,

	unsigned dst_pos, unsigned dst_stride,

	unsigned src_pos, unsigned src_stride,

	unsigned n, int sign)

{

	int i;

	if (!dim_map)

		return;

	for (i = 0; i < n; ++i) {

		unsigned d = 1 + dst_pos + dst_stride * i;

		unsigned s = 1 + src_pos + src_stride * i;

		dim_map->m[d].pos = s;

		dim_map->m[d].sgn = sign;

	}

}

void isl_dim_map_dim_range(__isl_keep isl_dim_map *dim_map,

	__isl_keep isl_space *dim, enum isl_dim_type type,

	unsigned first, unsigned n, unsigned dst_pos)

{

	int i;

	unsigned src_pos;

	if (!dim_map || !dim)

		return;

	src_pos = 1 + isl_space_offset(dim, type);

	for (i = 0; i < n; ++i) {

		dim_map->m[1 + dst_pos + i].pos = src_pos + first + i;

		dim_map->m[1 + dst_pos + i].sgn = 1;

	}

}

void isl_dim_map_dim(__isl_keep isl_dim_map *dim_map, __isl_keep isl_space *dim,

	enum isl_dim_type type, unsigned dst_pos)

{

	isl_dim_map_dim_range(dim_map, dim, type,

			      0, isl_space_dim(dim, type), dst_pos);

}

void isl_dim_map_div(__isl_keep isl_dim_map *dim_map,

	__isl_keep isl_basic_map *bmap, unsigned dst_pos)

{

	int i;

	unsigned src_pos;

	if (!dim_map || !bmap)

		return;

	src_pos = 1 + isl_space_dim(bmap->dim, isl_dim_all);

	for (i = 0; i < bmap->n_div; ++i) {

		dim_map->m[1 + dst_pos + i].pos = src_pos + i;

		dim_map->m[1 + dst_pos + i].sgn = 1;

	}

}

void isl_dim_map_dump(struct isl_dim_map *dim_map)

{

	int i;

	for (i = 0; i < dim_map->len; ++i)

		fprintf(stderr, "%d -> %d * %d; ", i,

			dim_map->m[i].sgn, dim_map->m[i].pos);

	fprintf(stderr, "\n");

}

static void copy_constraint_dim_map(isl_int *dst, isl_int *src,

					struct isl_dim_map *dim_map)

{

	int i;

	for (i = 0; i < dim_map->len; ++i) {

		if (dim_map->m[i].sgn == 0)

			isl_int_set_si(dst[i], 0);

		else if (dim_map->m[i].sgn > 0)

			isl_int_set(dst[i], src[dim_map->m[i].pos]);

		else

			isl_int_neg(dst[i], src[dim_map->m[i].pos]);

	}

}

static void copy_div_dim_map(isl_int *dst, isl_int *src,

					struct isl_dim_map *dim_map)

{

	isl_int_set(dst[0], src[0]);

	copy_constraint_dim_map(dst+1, src+1, dim_map);

}

__isl_give isl_basic_map *isl_basic_map_add_constraints_dim_map(

	__isl_take isl_basic_map *dst, __isl_take isl_basic_map *src,

	__isl_take isl_dim_map *dim_map)

{

	int i;

	if (!src || !dst || !dim_map)

		goto error;

	for (i = 0; i < src->n_eq; ++i) {

		int i1 = isl_basic_map_alloc_equality(dst);

		if (i1 < 0)

			goto error;

		copy_constraint_dim_map(dst->eq[i1], src->eq[i], dim_map);

	}

	for (i = 0; i < src->n_ineq; ++i) {

		int i1 = isl_basic_map_alloc_inequality(dst);

		if (i1 < 0)

			goto error;

		copy_constraint_dim_map(dst->ineq[i1], src->ineq[i], dim_map);

	}

	for (i = 0; i < src->n_div; ++i) {

		int i1 = isl_basic_map_alloc_div(dst);

		if (i1 < 0)

			goto error;

		copy_div_dim_map(dst->div[i1], src->div[i], dim_map);

	}

	free(dim_map);

	isl_basic_map_free(src);

	return dst;

error:

	free(dim_map);

	isl_basic_map_free(src);

	isl_basic_map_free(dst);

	return NULL;

}

__isl_give isl_basic_set *isl_basic_set_add_constraints_dim_map(

	__isl_take isl_basic_set *dst, __isl_take isl_basic_set *src,

	__isl_take isl_dim_map *dim_map)

{

	return isl_basic_map_add_constraints_dim_map(dst, src, dim_map);

}

/* Extend the given dim_map with mappings for the divs in bmap.

 */

__isl_give isl_dim_map *isl_dim_map_extend(__isl_keep isl_dim_map *dim_map,

	__isl_keep isl_basic_map *bmap)

{

	int i;

	struct isl_dim_map *res;

	int offset;

	offset = isl_basic_map_offset(bmap, isl_dim_div);

	res = isl_dim_map_alloc(bmap->ctx, dim_map->len - 1 + bmap->n_div);

	if (!res)

		return NULL;

	for (i = 0; i < dim_map->len; ++i)

		res->m[i] = dim_map->m[i];

	for (i = 0; i < bmap->n_div; ++i) {

		res->m[dim_map->len + i].pos = offset + i;

		res->m[dim_map->len + i].sgn = 1;

	}

	return res;

}

/* Extract a dim_map from a reordering.

 * We essentially need to reverse the mapping, and add an offset

 * of 1 for the constant term.

 */

__isl_give isl_dim_map *isl_dim_map_from_reordering(

	__isl_keep isl_reordering *exp)

{

	int i;

	isl_ctx *ctx;

	struct isl_dim_map *dim_map;

	if (!exp)

		return NULL;

	ctx = isl_space_get_ctx(exp->dim);

	dim_map = isl_dim_map_alloc(ctx, isl_space_dim(exp->dim, isl_dim_all));

	if (!dim_map)

		return NULL;

	for (i = 0; i < exp->len; ++i) {

		dim_map->m[1 + exp->pos[i]].pos = 1 + i;

		dim_map->m[1 + exp->pos[i]].sgn = 1;

	}

	return dim_map;

}