handle pencil independent pragmas

[pet.git] / tree.c

/*
 * Copyright 2011      Leiden University. All rights reserved.
 * Copyright 2014      Ecole Normale Superieure. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *    1. Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *
 *    2. Redistributions in binary form must reproduce the above
 *       copyright notice, this list of conditions and the following
 *       disclaimer in the documentation and/or other materials provided
 *       with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY LEIDEN UNIVERSITY ''AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL LEIDEN UNIVERSITY OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,
 * OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * The views and conclusions contained in the software and documentation
 * are those of the authors and should not be interpreted as
 * representing official policies, either expressed or implied, of
 * Leiden University.
 */

#include <string.h>

#include "expr.h"
#include "loc.h"
#include "tree.h"

#define ARRAY_SIZE(array) (sizeof(array)/sizeof(*array))

static const char *type_str[] = {
        [pet_tree_block] = "block",
        [pet_tree_break] = "break",
        [pet_tree_continue] = "continue",
        [pet_tree_decl] = "declaration",
        [pet_tree_decl_init] = "declaration-init",
        [pet_tree_expr] = "expression",
        [pet_tree_for] = "for",
        [pet_tree_infinite_loop] = "infinite-loop",
        [pet_tree_if] = "if",
        [pet_tree_if_else] = "if-else",
        [pet_tree_while] = "while",
};

/* Return a textual representation of the type "type".
 */
const char *pet_tree_type_str(enum pet_tree_type type)
{
        if (type < 0)
                return "error";
        return type_str[type];
}

/* Extract a type from its textual representation "str".
 */
enum pet_tree_type pet_tree_str_type(const char *str)
{
        int i;

        for (i = 0; i < ARRAY_SIZE(type_str); ++i)
                if (!strcmp(type_str[i], str))
                        return i;

        return pet_tree_error;
}

/* Return a new pet_tree of the given type.
 *
 * The location is initializaed to pet_loc_dummy.
 */
__isl_give pet_tree *pet_tree_alloc(isl_ctx *ctx, enum pet_tree_type type)
{
        pet_tree *tree;

        tree = isl_calloc_type(ctx, struct pet_tree);
        if (!tree)
                return NULL;

        tree->ctx = ctx;
        isl_ctx_ref(ctx);
        tree->ref = 1;
        tree->type = type;
        tree->loc = &pet_loc_dummy;

        return tree;
}

/* Return a new pet_tree representing the declaration (without initialization)
 * of the variable "var".
 */
__isl_give pet_tree *pet_tree_new_decl(__isl_take pet_expr *var)
{
        isl_ctx *ctx;
        pet_tree *tree;

        if (!var)
                return NULL;
        ctx = pet_expr_get_ctx(var);
        tree = pet_tree_alloc(ctx, pet_tree_decl);
        if (!tree)
                goto error;

        tree->u.d.var = var;

        return tree;
error:
        pet_expr_free(var);
        return NULL;
}

/* Return a new pet_tree representing the declaration of the variable "var"
 * with initial value "init".
 */
__isl_give pet_tree *pet_tree_new_decl_init(__isl_take pet_expr *var,
        __isl_take pet_expr *init)
{
        isl_ctx *ctx;
        pet_tree *tree;

        if (!var || !init)
                goto error;
        ctx = pet_expr_get_ctx(var);
        tree = pet_tree_alloc(ctx, pet_tree_decl_init);
        if (!tree)
                goto error;

        tree->u.d.var = var;
        tree->u.d.init = init;

        return tree;
error:
        pet_expr_free(var);
        pet_expr_free(init);
        return NULL;
}

/* Return a new pet_tree representing the expression "expr".
 */
__isl_give pet_tree *pet_tree_new_expr(__isl_take pet_expr *expr)
{
        isl_ctx *ctx;
        pet_tree *tree;

        if (!expr)
                return NULL;
        ctx = pet_expr_get_ctx(expr);
        tree = pet_tree_alloc(ctx, pet_tree_expr);
        if (!tree)
                goto error;

        tree->u.e.expr = expr;

        return tree;
error:
        pet_expr_free(expr);
        return NULL;
}

/* Return a new pet_tree representing an intially empty sequence
 * of trees with room for "n" trees.
 * "block" indicates whether the sequence has its own scope.
 */
__isl_give pet_tree *pet_tree_new_block(isl_ctx *ctx, int block, int n)
{
        pet_tree *tree;

        tree = pet_tree_alloc(ctx, pet_tree_block);
        if (!tree)
                return NULL;
        tree->u.b.block = block;
        tree->u.b.n = 0;
        tree->u.b.max = n;
        tree->u.b.child = isl_calloc_array(ctx, pet_tree *, n);
        if (n && !tree->u.b.child)
                return pet_tree_free(tree);

        return tree;
}

/* Return a new pet_tree representing a break statement.
 */
__isl_give pet_tree *pet_tree_new_break(isl_ctx *ctx)
{
        return pet_tree_alloc(ctx, pet_tree_break);
}

/* Return a new pet_tree representing a continue statement.
 */
__isl_give pet_tree *pet_tree_new_continue(isl_ctx *ctx)
{
        return pet_tree_alloc(ctx, pet_tree_continue);
}

/* Return a new pet_tree representing a for loop
 * with induction variable "iv", initial value for the induction
 * variable "init", loop condition "cond", induction variable increment "inc"
 * and loop body "body".  "declared" indicates whether the induction variable
 * is declared by the loop.  "independent" is set if the for loop is marked
 * independent.
 *
 * The location of the loop is initialized to that of the body.
 */
__isl_give pet_tree *pet_tree_new_for(int independent, int declared,
        __isl_take pet_expr *iv, __isl_take pet_expr *init,
        __isl_take pet_expr *cond, __isl_take pet_expr *inc,
        __isl_take pet_tree *body)
{
        isl_ctx *ctx;
        pet_tree *tree;

        if (!iv || !init || !cond || !inc || !body)
                goto error;
        ctx = pet_tree_get_ctx(body);
        tree = pet_tree_alloc(ctx, pet_tree_for);
        if (!tree)
                goto error;

        tree->u.l.independent = independent;
        tree->u.l.declared = declared;
        tree->u.l.iv = iv;
        tree->u.l.init = init;
        tree->u.l.cond = cond;
        tree->u.l.inc = inc;
        tree->u.l.body = body;
        tree->loc = pet_tree_get_loc(body);
        if (!tree->loc)
                return pet_tree_free(tree);

        return tree;
error:
        pet_expr_free(iv);
        pet_expr_free(init);
        pet_expr_free(cond);
        pet_expr_free(inc);
        pet_tree_free(body);
        return NULL;
}

/* Return a new pet_tree representing a while loop
 * with loop condition "cond" and loop body "body".
 *
 * The location of the loop is initialized to that of the body.
 */
__isl_give pet_tree *pet_tree_new_while(__isl_take pet_expr *cond,
        __isl_take pet_tree *body)
{
        isl_ctx *ctx;
        pet_tree *tree;

        if (!cond || !body)
                goto error;
        ctx = pet_tree_get_ctx(body);
        tree = pet_tree_alloc(ctx, pet_tree_while);
        if (!tree)
                goto error;

        tree->u.l.cond = cond;
        tree->u.l.body = body;
        tree->loc = pet_tree_get_loc(body);
        if (!tree->loc)
                return pet_tree_free(tree);

        return tree;
error:
        pet_expr_free(cond);
        pet_tree_free(body);
        return NULL;
}

/* Return a new pet_tree representing an infinite loop
 * with loop body "body".
 *
 * The location of the loop is initialized to that of the body.
 */
__isl_give pet_tree *pet_tree_new_infinite_loop(__isl_take pet_tree *body)
{
        isl_ctx *ctx;
        pet_tree *tree;

        if (!body)
                return NULL;
        ctx = pet_tree_get_ctx(body);
        tree = pet_tree_alloc(ctx, pet_tree_infinite_loop);
        if (!tree)
                return pet_tree_free(body);

        tree->u.l.body = body;
        tree->loc = pet_tree_get_loc(body);
        if (!tree->loc)
                return pet_tree_free(tree);

        return tree;
}

/* Return a new pet_tree representing an if statement
 * with condition "cond" and then branch "then_body".
 *
 * The location of the if statement is initialized to that of the body.
 */
__isl_give pet_tree *pet_tree_new_if(__isl_take pet_expr *cond,
        __isl_take pet_tree *then_body)
{
        isl_ctx *ctx;
        pet_tree *tree;

        if (!cond || !then_body)
                goto error;
        ctx = pet_tree_get_ctx(then_body);
        tree = pet_tree_alloc(ctx, pet_tree_if);
        if (!tree)
                goto error;

        tree->u.i.cond = cond;
        tree->u.i.then_body = then_body;
        tree->loc = pet_tree_get_loc(then_body);
        if (!tree->loc)
                return pet_tree_free(tree);

        return tree;
error:
        pet_expr_free(cond);
        pet_tree_free(then_body);
        return NULL;
}

/* Return a new pet_tree representing an if statement
 * with condition "cond", then branch "then_body" and else branch "else_body".
 *
 * The location of the if statement is initialized to cover
 * those of the bodies.
 */
__isl_give pet_tree *pet_tree_new_if_else(__isl_take pet_expr *cond,
        __isl_take pet_tree *then_body, __isl_take pet_tree *else_body)
{
        isl_ctx *ctx;
        pet_tree *tree;

        if (!cond || !then_body || !else_body)
                goto error;
        ctx = pet_tree_get_ctx(then_body);
        tree = pet_tree_alloc(ctx, pet_tree_if_else);
        if (!tree)
                goto error;

        tree->u.i.cond = cond;
        tree->u.i.then_body = then_body;
        tree->u.i.else_body = else_body;
        tree->loc = pet_tree_get_loc(then_body);
        tree->loc = pet_loc_update_start_end_from_loc(tree->loc,
                                                        else_body->loc);
        if (!tree->loc)
                return pet_tree_free(tree);

        return tree;
error:
        pet_expr_free(cond);
        pet_tree_free(then_body);
        pet_tree_free(else_body);
        return NULL;
}

/* Return an independent duplicate of "tree".
 */
static __isl_give pet_tree *pet_tree_dup(__isl_keep pet_tree *tree)
{
        int i;
        pet_tree *dup;

        if (!tree)
                return NULL;

        switch (tree->type) {
        case pet_tree_error:
                return NULL;
        case pet_tree_block:
                dup = pet_tree_new_block(tree->ctx, tree->u.b.block,
                                        tree->u.b.n);
                for (i = 0; i < tree->u.b.n; ++i)
                        dup = pet_tree_block_add_child(dup,
                                        pet_tree_copy(tree->u.b.child[i]));
                break;
        case pet_tree_break:
                dup = pet_tree_new_break(tree->ctx);
                break;
        case pet_tree_continue:
                dup = pet_tree_new_continue(tree->ctx);
                break;
        case pet_tree_decl:
                dup = pet_tree_new_decl(pet_expr_copy(tree->u.d.var));
                break;
        case pet_tree_decl_init:
                dup = pet_tree_new_decl_init(pet_expr_copy(tree->u.d.var),
                                            pet_expr_copy(tree->u.d.init));
                break;
        case pet_tree_expr:
                dup = pet_tree_new_expr(pet_expr_copy(tree->u.e.expr));
                break;
        case pet_tree_for:
                dup = pet_tree_new_for(tree->u.l.independent,
                    tree->u.l.declared,
                    pet_expr_copy(tree->u.l.iv), pet_expr_copy(tree->u.l.init),
                    pet_expr_copy(tree->u.l.cond), pet_expr_copy(tree->u.l.inc),
                    pet_tree_copy(tree->u.l.body));
                break;
        case pet_tree_while:
                dup = pet_tree_new_while(pet_expr_copy(tree->u.l.cond),
                                        pet_tree_copy(tree->u.l.body));
                break;
        case pet_tree_infinite_loop:
                dup = pet_tree_new_infinite_loop(pet_tree_copy(tree->u.l.body));
                break;
        case pet_tree_if:
                dup = pet_tree_new_if(pet_expr_copy(tree->u.i.cond),
                                        pet_tree_copy(tree->u.i.then_body));
                break;
        case pet_tree_if_else:
                dup = pet_tree_new_if_else(pet_expr_copy(tree->u.i.cond),
                                        pet_tree_copy(tree->u.i.then_body),
                                        pet_tree_copy(tree->u.i.else_body));
                break;
        }

        if (!dup)
                return NULL;
        pet_loc_free(dup->loc);
        dup->loc = pet_loc_copy(tree->loc);
        if (!dup->loc)
                return pet_tree_free(dup);
        if (tree->label) {
                dup->label = isl_id_copy(tree->label);
                if (!dup->label)
                        return pet_tree_free(dup);
        }

        return dup;
}

/* Return a pet_tree that is equal to "tree" and that has only one reference.
 */
__isl_give pet_tree *pet_tree_cow(__isl_take pet_tree *tree)
{
        if (!tree)
                return NULL;

        if (tree->ref == 1)
                return tree;
        tree->ref--;
        return pet_tree_dup(tree);
}

/* Return an extra reference to "tree".
 */
__isl_give pet_tree *pet_tree_copy(__isl_keep pet_tree *tree)
{
        if (!tree)
                return NULL;

        tree->ref++;
        return tree;
}

/* Free a reference to "tree".
 */
__isl_null pet_tree *pet_tree_free(__isl_take pet_tree *tree)
{
        int i;

        if (!tree)
                return NULL;
        if (--tree->ref > 0)
                return NULL;

        pet_loc_free(tree->loc);
        isl_id_free(tree->label);

        switch (tree->type) {
        case pet_tree_error:
                break;
        case pet_tree_block:
                for (i = 0; i < tree->u.b.n; ++i)
                        pet_tree_free(tree->u.b.child[i]);
                free(tree->u.b.child);
                break;
        case pet_tree_break:
        case pet_tree_continue:
                break;
        case pet_tree_decl_init:
                pet_expr_free(tree->u.d.init);
        case pet_tree_decl:
                pet_expr_free(tree->u.d.var);
                break;
        case pet_tree_expr:
                pet_expr_free(tree->u.e.expr);
                break;
        case pet_tree_for:
                pet_expr_free(tree->u.l.iv);
                pet_expr_free(tree->u.l.init);
                pet_expr_free(tree->u.l.inc);
        case pet_tree_while:
                pet_expr_free(tree->u.l.cond);
        case pet_tree_infinite_loop:
                pet_tree_free(tree->u.l.body);
                break;
        case pet_tree_if_else:
                pet_tree_free(tree->u.i.else_body);
        case pet_tree_if:
                pet_expr_free(tree->u.i.cond);
                pet_tree_free(tree->u.i.then_body);
                break;
        }

        isl_ctx_deref(tree->ctx);
        free(tree);
        return NULL;
}

/* Return the isl_ctx in which "tree" was created.
 */
isl_ctx *pet_tree_get_ctx(__isl_keep pet_tree *tree)
{
        return tree ? tree->ctx : NULL;
}

/* Return the location of "tree".
 */
__isl_give pet_loc *pet_tree_get_loc(__isl_keep pet_tree *tree)
{
        return tree ? pet_loc_copy(tree->loc) : NULL;
}

/* Return the type of "tree".
 */
enum pet_tree_type pet_tree_get_type(__isl_keep pet_tree *tree)
{
        if (!tree)
                return pet_tree_error;

        return tree->type;
}

/* Replace the location of "tree" by "loc".
 */
__isl_give pet_tree *pet_tree_set_loc(__isl_take pet_tree *tree,
        __isl_take pet_loc *loc)
{
        tree = pet_tree_cow(tree);
        if (!tree || !loc)
                goto error;

        pet_loc_free(tree->loc);
        tree->loc = loc;

        return tree;
error:
        pet_loc_free(loc);
        pet_tree_free(tree);
        return NULL;
}

/* Replace the label of "tree" by "label".
 */
__isl_give pet_tree *pet_tree_set_label(__isl_take pet_tree *tree,
        __isl_take isl_id *label)
{
        tree = pet_tree_cow(tree);
        if (!tree || !label)
                goto error;

        isl_id_free(tree->label);
        tree->label = label;

        return tree;
error:
        isl_id_free(label);
        return pet_tree_free(tree);
}

/* Given an expression tree "tree", return the associated expression.
 */
__isl_give pet_expr *pet_tree_expr_get_expr(__isl_keep pet_tree *tree)
{
        if (!tree)
                return NULL;
        if (pet_tree_get_type(tree) != pet_tree_expr)
                isl_die(pet_tree_get_ctx(tree), isl_error_invalid,
                        "not an expression tree", return NULL);

        return pet_expr_copy(tree->u.e.expr);
}

/* Given a block tree "tree", return the number of children in the sequence.
 */
int pet_tree_block_n_child(__isl_keep pet_tree *tree)
{
        if (!tree)
                return -1;
        if (pet_tree_get_type(tree) != pet_tree_block)
                isl_die(pet_tree_get_ctx(tree), isl_error_invalid,
                        "not a block tree", return -1);

        return tree->u.b.n;
}

/* Add "child" to the sequence of trees represented by "block".
 *
 * Update the location of "block" to include that of "child".
 */
__isl_give pet_tree *pet_tree_block_add_child(__isl_take pet_tree *block,
        __isl_take pet_tree *child)
{
        block = pet_tree_cow(block);
        if (!block || !child)
                goto error;
        if (block->type != pet_tree_block)
                isl_die(pet_tree_get_ctx(block), isl_error_invalid,
                        "not a block tree", goto error);
        if (block->u.b.n >= block->u.b.max)
                isl_die(pet_tree_get_ctx(block), isl_error_invalid,
                        "out of space in block", goto error);

        block->loc = pet_loc_update_start_end_from_loc(block->loc, child->loc);
        block->u.b.child[block->u.b.n++] = child;

        if (!block->loc)
                return pet_tree_free(block);

        return block;
error:
        pet_tree_free(block);
        pet_tree_free(child);
        return NULL;
}

/* Given a block tree "tree", return the child at position "pos".
 */
__isl_give pet_tree *pet_tree_block_get_child(__isl_keep pet_tree *tree,
        int pos)
{
        if (!tree)
                return NULL;
        if (pet_tree_get_type(tree) != pet_tree_block)
                isl_die(pet_tree_get_ctx(tree), isl_error_invalid,
                        "not a block tree", return NULL);
        if (pos < 0 || pos >= tree->u.b.n)
                isl_die(pet_tree_get_ctx(tree), isl_error_invalid,
                        "position out of bounds", return NULL);

        return pet_tree_copy(tree->u.b.child[pos]);
}

/* Does "tree" represent a declaration (with or without initialization?
 */
int pet_tree_is_decl(__isl_keep pet_tree *tree)
{
        if (!tree)
                return -1;

        switch (pet_tree_get_type(tree)) {
        case pet_tree_decl:
        case pet_tree_decl_init:
                return 1;
        default:
                return 0;
        }
}

/* Given a declaration tree "tree", return the variable that is being
 * declared.
 */
__isl_give pet_expr *pet_tree_decl_get_var(__isl_keep pet_tree *tree)
{
        if (!tree)
                return NULL;
        if (!pet_tree_is_decl(tree))
                isl_die(pet_tree_get_ctx(tree), isl_error_invalid,
                        "not a decl tree", return NULL);

        return pet_expr_copy(tree->u.d.var);
}

/* Given a declaration tree with initialization "tree",
 * return the initial value of the declared variable.
 */
__isl_give pet_expr *pet_tree_decl_get_init(__isl_keep pet_tree *tree)
{
        if (!tree)
                return NULL;
        if (pet_tree_get_type(tree) != pet_tree_decl_init)
                isl_die(pet_tree_get_ctx(tree), isl_error_invalid,
                        "not a decl_init tree", return NULL);

        return pet_expr_copy(tree->u.d.init);
}

/* Given an if tree "tree", return the if condition.
 */
__isl_give pet_expr *pet_tree_if_get_cond(__isl_keep pet_tree *tree)
{
        enum pet_tree_type type;

        if (!tree)
                return NULL;
        type = pet_tree_get_type(tree);
        if (type != pet_tree_if && type != pet_tree_if_else)
                isl_die(pet_tree_get_ctx(tree), isl_error_invalid,
                        "not an if tree", return NULL);

        return pet_expr_copy(tree->u.i.cond);
}

/* Given an if tree "tree", return the body of the then branch.
 */
__isl_give pet_tree *pet_tree_if_get_then(__isl_keep pet_tree *tree)
{
        enum pet_tree_type type;

        if (!tree)
                return NULL;
        type = pet_tree_get_type(tree);
        if (type != pet_tree_if && type != pet_tree_if_else)
                isl_die(pet_tree_get_ctx(tree), isl_error_invalid,
                        "not an if tree", return NULL);

        return pet_tree_copy(tree->u.i.then_body);
}

/* Given an if tree with an else branch "tree",
 * return the body of that else branch.
 */
__isl_give pet_tree *pet_tree_if_get_else(__isl_keep pet_tree *tree)
{
        if (!tree)
                return NULL;
        if (pet_tree_get_type(tree) != pet_tree_if_else)
                isl_die(pet_tree_get_ctx(tree), isl_error_invalid,
                        "not an if tree with an else branch", return NULL);

        return pet_tree_copy(tree->u.i.else_body);
}

/* Does "tree" represent some type of loop?
 */
int pet_tree_is_loop(__isl_keep pet_tree *tree)
{
        if (!tree)
                return -1;

        switch (pet_tree_get_type(tree)) {
        case pet_tree_for:
        case pet_tree_infinite_loop:
        case pet_tree_while:
                return 1;
        default:
                return 0;
        }
}

/* Given a for loop "tree", return the induction variable.
 */
__isl_give pet_expr *pet_tree_loop_get_var(__isl_keep pet_tree *tree)
{
        if (!tree)
                return NULL;
        if (pet_tree_get_type(tree) != pet_tree_for)
                isl_die(pet_tree_get_ctx(tree), isl_error_invalid,
                        "not a for tree", return NULL);

        return pet_expr_copy(tree->u.l.iv);
}

/* Given a for loop "tree", return the initial value of the induction variable.
 */
__isl_give pet_expr *pet_tree_loop_get_init(__isl_keep pet_tree *tree)
{
        if (!tree)
                return NULL;
        if (pet_tree_get_type(tree) != pet_tree_for)
                isl_die(pet_tree_get_ctx(tree), isl_error_invalid,
                        "not a for tree", return NULL);

        return pet_expr_copy(tree->u.l.init);
}

/* Given a loop "tree", return the loop condition.
 *
 * For an infinite loop, the loop condition always holds,
 * so we simply return "1".
 */
__isl_give pet_expr *pet_tree_loop_get_cond(__isl_keep pet_tree *tree)
{
        enum pet_tree_type type;

        if (!tree)
                return NULL;
        type = pet_tree_get_type(tree);
        if (type == pet_tree_infinite_loop)
                return pet_expr_new_int(isl_val_one(pet_tree_get_ctx(tree)));
        if (type != pet_tree_for && type != pet_tree_while)
                isl_die(pet_tree_get_ctx(tree), isl_error_invalid,
                        "not a for or while tree", return NULL);

        return pet_expr_copy(tree->u.l.cond);
}

/* Given a for loop "tree", return the increment of the induction variable.
 */
__isl_give pet_expr *pet_tree_loop_get_inc(__isl_keep pet_tree *tree)
{
        if (!tree)
                return NULL;
        if (pet_tree_get_type(tree) != pet_tree_for)
                isl_die(pet_tree_get_ctx(tree), isl_error_invalid,
                        "not a for tree", return NULL);

        return pet_expr_copy(tree->u.l.inc);
}

/* Given a loop tree "tree", return the body.
 */
__isl_give pet_tree *pet_tree_loop_get_body(__isl_keep pet_tree *tree)
{
        if (!tree)
                return NULL;

        if (!pet_tree_is_loop(tree))
                isl_die(pet_tree_get_ctx(tree), isl_error_invalid,
                        "not a loop tree", return NULL);

        return pet_tree_copy(tree->u.l.body);
}

/* Call "fn" on each node of "tree", including "tree" itself.
 *
 * Return 0 on success and -1 on error, where "fn" returning a negative
 * value is treated as an error.
 */
int pet_tree_foreach_sub_tree(__isl_keep pet_tree *tree,
        int (*fn)(__isl_keep pet_tree *tree, void *user), void *user)
{
        int i;

        if (!tree)
                return -1;

        if (fn(tree, user) < 0)
                return -1;

        switch (tree->type) {
        case pet_tree_error:
                return -1;
        case pet_tree_block:
                for (i = 0; i < tree->u.b.n; ++i)
                        if (pet_tree_foreach_sub_tree(tree->u.b.child[i],
                                                        fn, user) < 0)
                                return -1;
                break;
        case pet_tree_break:
        case pet_tree_continue:
        case pet_tree_decl:
        case pet_tree_decl_init:
        case pet_tree_expr:
                break;
        case pet_tree_if:
                if (pet_tree_foreach_sub_tree(tree->u.i.then_body,
                                                fn, user) < 0)
                        return -1;
                break;
        case pet_tree_if_else:
                if (pet_tree_foreach_sub_tree(tree->u.i.then_body,
                                                fn, user) < 0)
                        return -1;
                if (pet_tree_foreach_sub_tree(tree->u.i.else_body,
                                                fn, user) < 0)
                        return -1;
                break;
        case pet_tree_while:
        case pet_tree_for:
        case pet_tree_infinite_loop:
                if (pet_tree_foreach_sub_tree(tree->u.l.body, fn, user) < 0)
                        return -1;
                break;
        }

        return 0;
}

/* Intermediate data structure for foreach_expr.
 *
 * "fn" is the function that needs to be called on each expression.
 * "user" is the user argument to be passed to "fn".
 */
struct pet_tree_foreach_expr_data {
        int (*fn)(__isl_keep pet_expr *expr, void *user);
        void *user;
};

/* Call data->fn on each expression in the "tree" object.
 * This function is used as a callback to pet_tree_foreach_sub_tree
 * to implement pet_tree_foreach_expr.
 *
 * Return 0 on success and -1 on error, where data->fn returning a negative
 * value is treated as an error.
 */
static int foreach_expr(__isl_keep pet_tree *tree, void *user)
{
        struct pet_tree_foreach_expr_data *data = user;

        if (!tree)
                return -1;

        switch (tree->type) {
        case pet_tree_error:
                return -1;
        case pet_tree_block:
        case pet_tree_break:
        case pet_tree_continue:
        case pet_tree_infinite_loop:
                break;
        case pet_tree_decl:
                if (data->fn(tree->u.d.var, data->user) < 0)
                        return -1;
                break;
        case pet_tree_decl_init:
                if (data->fn(tree->u.d.var, data->user) < 0)
                        return -1;
                if (data->fn(tree->u.d.init, data->user) < 0)
                        return -1;
                break;
        case pet_tree_expr:
                if (data->fn(tree->u.e.expr, data->user) < 0)
                        return -1;
                break;
        case pet_tree_if:
                if (data->fn(tree->u.i.cond, data->user) < 0)
                        return -1;
                break;
        case pet_tree_if_else:
                if (data->fn(tree->u.i.cond, data->user) < 0)
                        return -1;
                break;
        case pet_tree_while:
                if (data->fn(tree->u.l.cond, data->user) < 0)
                        return -1;
                break;
        case pet_tree_for:
                if (data->fn(tree->u.l.iv, data->user) < 0)
                        return -1;
                if (data->fn(tree->u.l.init, data->user) < 0)
                        return -1;
                if (data->fn(tree->u.l.cond, data->user) < 0)
                        return -1;
                if (data->fn(tree->u.l.inc, data->user) < 0)
                        return -1;
                break;
        }

        return 0;
}

/* Call "fn" on each top-level expression in the nodes of "tree"
 *
 * Return 0 on success and -1 on error, where "fn" returning a negative
 * value is treated as an error.
 *
 * We run over all nodes in "tree" and call "fn"
 * on each expression in those nodes.
 */
int pet_tree_foreach_expr(__isl_keep pet_tree *tree,
        int (*fn)(__isl_keep pet_expr *expr, void *user), void *user)
{
        struct pet_tree_foreach_expr_data data = { fn, user };

        return pet_tree_foreach_sub_tree(tree, &foreach_expr, &data);
}

/* Intermediate data structure for foreach_access_expr.
 *
 * "fn" is the function that needs to be called on each access subexpression.
 * "user" is the user argument to be passed to "fn".
 */
struct pet_tree_foreach_access_expr_data {
        int (*fn)(__isl_keep pet_expr *expr, void *user);
        void *user;
};

/* Call data->fn on each access subexpression of "expr".
 * This function is used as a callback to pet_tree_foreach_expr
 * to implement pet_tree_foreach_access_expr.
 *
 * Return 0 on success and -1 on error, where data->fn returning a negative
 * value is treated as an error.
 */
static int foreach_access_expr(__isl_keep pet_expr *expr, void *user)
{
        struct pet_tree_foreach_access_expr_data *data = user;

        return pet_expr_foreach_access_expr(expr, data->fn, data->user);
}

/* Call "fn" on each access subexpression in the nodes of "tree"
 *
 * Return 0 on success and -1 on error, where "fn" returning a negative
 * value is treated as an error.
 *
 * We run over all expressions in the nodes of "tree" and call "fn"
 * on each access subexpression of those expressions.
 */
int pet_tree_foreach_access_expr(__isl_keep pet_tree *tree,
        int (*fn)(__isl_keep pet_expr *expr, void *user), void *user)
{
        struct pet_tree_foreach_access_expr_data data = { fn, user };

        return pet_tree_foreach_expr(tree, &foreach_access_expr, &data);
}

/* Modify all top-level expressions in the nodes of "tree"
 * by calling "fn" on them.
 */
__isl_give pet_tree *pet_tree_map_expr(__isl_take pet_tree *tree,
        __isl_give pet_expr *(*fn)(__isl_take pet_expr *expr, void *user),
        void *user)
{
        int i;

        tree = pet_tree_cow(tree);
        if (!tree)
                return NULL;

        switch (tree->type) {
        case pet_tree_error:
                return pet_tree_free(tree);
        case pet_tree_block:
                for (i = 0; i < tree->u.b.n; ++i) {
                        tree->u.b.child[i] =
                            pet_tree_map_expr(tree->u.b.child[i], fn, user);
                        if (!tree->u.b.child[i])
                                return pet_tree_free(tree);
                }
                break;
        case pet_tree_break:
        case pet_tree_continue:
                break;
        case pet_tree_decl:
                tree->u.d.var = fn(tree->u.d.var, user);
                if (!tree->u.d.var)
                        return pet_tree_free(tree);
                break;
        case pet_tree_decl_init:
                tree->u.d.var = fn(tree->u.d.var, user);
                tree->u.d.init = fn(tree->u.d.init, user);
                if (!tree->u.d.var || !tree->u.d.init)
                        return pet_tree_free(tree);
                break;
        case pet_tree_expr:
                tree->u.e.expr = fn(tree->u.e.expr, user);
                if (!tree->u.e.expr)
                        return pet_tree_free(tree);
                break;
        case pet_tree_if:
                tree->u.i.cond = fn(tree->u.i.cond, user);
                tree->u.i.then_body =
                        pet_tree_map_expr(tree->u.i.then_body, fn, user);
                if (!tree->u.i.cond || !tree->u.i.then_body)
                        return pet_tree_free(tree);
                break;
        case pet_tree_if_else:
                tree->u.i.cond = fn(tree->u.i.cond, user);
                tree->u.i.then_body =
                        pet_tree_map_expr(tree->u.i.then_body, fn, user);
                tree->u.i.else_body =
                        pet_tree_map_expr(tree->u.i.else_body, fn, user);
                if (!tree->u.i.cond ||
                    !tree->u.i.then_body || !tree->u.i.else_body)
                        return pet_tree_free(tree);
                break;
        case pet_tree_while:
                tree->u.l.cond = fn(tree->u.l.cond, user);
                tree->u.l.body = pet_tree_map_expr(tree->u.l.body, fn, user);
                if (!tree->u.l.cond || !tree->u.l.body)
                        return pet_tree_free(tree);
                break;
        case pet_tree_for:
                tree->u.l.iv = fn(tree->u.l.iv, user);
                tree->u.l.init = fn(tree->u.l.init, user);
                tree->u.l.cond = fn(tree->u.l.cond, user);
                tree->u.l.inc = fn(tree->u.l.inc, user);
                tree->u.l.body = pet_tree_map_expr(tree->u.l.body, fn, user);
                if (!tree->u.l.iv || !tree->u.l.init || !tree->u.l.cond ||
                    !tree->u.l.inc || !tree->u.l.body)
                        return pet_tree_free(tree);
                break;
        case pet_tree_infinite_loop:
                tree->u.l.body = pet_tree_map_expr(tree->u.l.body, fn, user);
                if (!tree->u.l.body)
                        return pet_tree_free(tree);
                break;
        }

        return tree;
}

/* Intermediate data structure for map_access_expr.
 *
 * "fn" is the function that needs to be called on each access subexpression.
 * "user" is the user argument to be passed to "fn".
 */
struct pet_tree_map_access_expr_data {
        __isl_give pet_expr *(*fn)(__isl_take pet_expr *expr, void *user);
        void *user;
};

/* Modify all top-level expressions in the nodes of "tree"
 * by calling "fn" on them.
 *
 * This is a wrapper around pet_expr_map_access for use as a callback
 * to pet_tree_map_expr.
 */
static __isl_give pet_expr *map_access_expr(__isl_take pet_expr *expr,
        void *user)
{
        struct pet_tree_map_access_expr_data *data = user;

        return pet_expr_map_access(expr, data->fn, data->user);
}

/* Modify all access subexpressions in the nodes of "tree"
 * by calling "fn" on them.
 *
 * We run over all expressions in the nodes of "tree" and call "fn"
 * on each access subexpression of those expressions.
 */
__isl_give pet_tree *pet_tree_map_access_expr(__isl_take pet_tree *tree,
        __isl_give pet_expr *(*fn)(__isl_take pet_expr *expr, void *user),
        void *user)
{
        struct pet_tree_map_access_expr_data data = { fn, user };

        return pet_tree_map_expr(tree, &map_access_expr, &data);
}

/* Wrapper around pet_expr_align_params
 * for use as a pet_tree_map_expr callback.
 */
static __isl_give pet_expr *align_params(__isl_take pet_expr *expr,
        void *user)
{
        isl_space *space = user;

        return pet_expr_align_params(expr, isl_space_copy(space));
}

/* Add all parameters in "space" to all access relations and index expressions
 * in "tree".
 */
__isl_give pet_tree *pet_tree_align_params(__isl_take pet_tree *tree,
        __isl_take isl_space *space)
{
        tree = pet_tree_map_expr(tree, &align_params, space);
        isl_space_free(space);
        return tree;
}

/* Wrapper around pet_expr_add_ref_ids
 * for use as a pet_tree_map_expr callback.
 */
static __isl_give pet_expr *add_ref_ids(__isl_take pet_expr *expr, void *user)
{
        int *n_ref = user;

        return pet_expr_add_ref_ids(expr, n_ref);
}

/* Add reference identifiers to all access expressions in "tree".
 * "n_ref" points to an integer that contains the sequence number
 * of the next reference.
 */
__isl_give pet_tree *pet_tree_add_ref_ids(__isl_take pet_tree *tree,
        int *n_ref)
{
        return pet_tree_map_expr(tree, &add_ref_ids, n_ref);
}

/* Wrapper around pet_expr_anonymize
 * for use as a pet_tree_map_expr callback.
 */
static __isl_give pet_expr *anonymize(__isl_take pet_expr *expr, void *user)
{
        return pet_expr_anonymize(expr);
}

/* Reset the user pointer on all parameter and tuple ids in "tree".
 */
__isl_give pet_tree *pet_tree_anonymize(__isl_take pet_tree *tree)
{
        return pet_tree_map_expr(tree, &anonymize, NULL);
}

/* Arguments to be passed to pet_expr_gist from the gist wrapper.
 */
struct pet_tree_gist_data {
        isl_set *domain;
        isl_union_map *value_bounds;
};

/* Wrapper around pet_expr_gist for use as a pet_tree_map_expr callback.
 */
static __isl_give pet_expr *gist(__isl_take pet_expr *expr, void *user)
{
        struct pet_tree_gist_data *data = user;

        return pet_expr_gist(expr, data->domain, data->value_bounds);
}

/* Compute the gist of all access relations and index expressions inside
 * "tree" based on the constraints on the parameters specified by "context"
 * and the constraints on the values of nested accesses specified
 * by "value_bounds".
 */
__isl_give pet_tree *pet_tree_gist(__isl_take pet_tree *tree,
        __isl_keep isl_set *context, __isl_keep isl_union_map *value_bounds)
{
        struct pet_tree_gist_data data = { context, value_bounds };

        return pet_tree_map_expr(tree, &gist, &data);
}

/* Return 1 if the two pet_tree objects are equivalent.
 *
 * We ignore the locations of the trees.
 */
int pet_tree_is_equal(__isl_keep pet_tree *tree1, __isl_keep pet_tree *tree2)
{
        int i;
        int equal;

        if (!tree1 || !tree2)
                return 0;

        if (tree1 == tree2)
                return 1;

        if (tree1->type != tree2->type)
                return 0;
        if (tree1->label != tree2->label)
                return 0;

        switch (tree1->type) {
        case pet_tree_error:
                return -1;
        case pet_tree_block:
                if (tree1->u.b.block != tree2->u.b.block)
                        return 0;
                if (tree1->u.b.n != tree2->u.b.n)
                        return 0;
                for (i = 0; i < tree1->u.b.n; ++i) {
                        equal = pet_tree_is_equal(tree1->u.b.child[i],
                                                tree2->u.b.child[i]);
                        if (equal < 0 || !equal)
                                return equal;
                }
                break;
        case pet_tree_break:
        case pet_tree_continue:
                break;
        case pet_tree_decl:
                return pet_expr_is_equal(tree1->u.d.var, tree2->u.d.var);
        case pet_tree_decl_init:
                equal = pet_expr_is_equal(tree1->u.d.var, tree2->u.d.var);
                if (equal < 0 || !equal)
                        return equal;
                return pet_expr_is_equal(tree1->u.d.init, tree2->u.d.init);
        case pet_tree_expr:
                return pet_expr_is_equal(tree1->u.e.expr, tree2->u.e.expr);
        case pet_tree_for:
                if (tree1->u.l.declared != tree2->u.l.declared)
                        return 0;
                equal = pet_expr_is_equal(tree1->u.l.iv, tree2->u.l.iv);
                if (equal < 0 || !equal)
                        return equal;
                equal = pet_expr_is_equal(tree1->u.l.init, tree2->u.l.init);
                if (equal < 0 || !equal)
                        return equal;
                equal = pet_expr_is_equal(tree1->u.l.cond, tree2->u.l.cond);
                if (equal < 0 || !equal)
                        return equal;
                equal = pet_expr_is_equal(tree1->u.l.inc, tree2->u.l.inc);
                if (equal < 0 || !equal)
                        return equal;
                return pet_tree_is_equal(tree1->u.l.body, tree2->u.l.body);
        case pet_tree_while:
                equal = pet_expr_is_equal(tree1->u.l.cond, tree2->u.l.cond);
                if (equal < 0 || !equal)
                        return equal;
                return pet_tree_is_equal(tree1->u.l.body, tree2->u.l.body);
        case pet_tree_infinite_loop:
                return pet_tree_is_equal(tree1->u.l.body, tree2->u.l.body);
        case pet_tree_if:
                equal = pet_expr_is_equal(tree1->u.i.cond, tree2->u.i.cond);
                if (equal < 0 || !equal)
                        return equal;
                return pet_tree_is_equal(tree1->u.i.then_body,
                                        tree2->u.i.then_body);
        case pet_tree_if_else:
                equal = pet_expr_is_equal(tree1->u.i.cond, tree2->u.i.cond);
                if (equal < 0 || !equal)
                        return equal;
                equal = pet_tree_is_equal(tree1->u.i.then_body,
                                        tree2->u.i.then_body);
                if (equal < 0 || !equal)
                        return equal;
                return pet_tree_is_equal(tree1->u.i.else_body,
                                        tree2->u.i.else_body);
        }

        return 1;
}

/* Is "tree" an expression tree that performs the operation "type"?
 */
static int pet_tree_is_op_of_type(__isl_keep pet_tree *tree,
        enum pet_op_type type)
{
        if (!tree)
                return 0;
        if (tree->type != pet_tree_expr)
                return 0;
        if (pet_expr_get_type(tree->u.e.expr) != pet_expr_op)
                return 0;
        return pet_expr_op_get_type(tree->u.e.expr) == type;
}

/* Is "tree" an expression tree that performs a kill operation?
 */
int pet_tree_is_kill(__isl_keep pet_tree *tree)
{
        return pet_tree_is_op_of_type(tree, pet_op_kill);
}

/* Is "tree" an expression tree that performs an assignment operation?
 */
int pet_tree_is_assign(__isl_keep pet_tree *tree)
{
        return pet_tree_is_op_of_type(tree, pet_op_assign);
}

/* Is "tree" an expression tree that performs an assume operation?
 */
int pet_tree_is_assume(__isl_keep pet_tree *tree)
{
        return pet_tree_is_op_of_type(tree, pet_op_assume);
}

/* Is "tree" an expression tree that performs an assume operation
 * such that the assumed expression is affine?
 */
int pet_tree_is_affine_assume(__isl_keep pet_tree *tree)
{
        if (!pet_tree_is_assume(tree))
                return 0;
        return pet_expr_is_affine(tree->u.e.expr->args[0]);
}

/* Given a tree that represent an assume operation expression
 * with an access as argument (possibly an affine expression),
 * return the index expression of that access.
 */
__isl_give isl_multi_pw_aff *pet_tree_assume_get_index(
        __isl_keep pet_tree *tree)
{
        if (!tree)
                return NULL;
        if (!pet_tree_is_assume(tree))
                isl_die(pet_tree_get_ctx(tree), isl_error_invalid,
                        "not an assume tree", return NULL);
        return pet_expr_access_get_index(tree->u.e.expr->args[0]);
}

/* Internal data structure for pet_tree_writes.
 * "id" is the identifier that we are looking for.
 * "writes" is set if we have found the identifier being written to.
 */
struct pet_tree_writes_data {
        isl_id *id;
        int writes;
};

/* Check if expr writes to data->id.
 * If so, set data->writes and abort the search.
 */
static int check_write(__isl_keep pet_expr *expr, void *user)
{
        struct pet_tree_writes_data *data = user;

        data->writes = pet_expr_writes(expr, data->id);
        if (data->writes < 0 || data->writes)
                return -1;

        return 0;
}

/* Is there any write access in "tree" that accesses "id"?
 */
int pet_tree_writes(__isl_keep pet_tree *tree, __isl_keep isl_id *id)
{
        struct pet_tree_writes_data data;

        data.id = id;
        data.writes = 0;
        if (pet_tree_foreach_expr(tree, &check_write, &data) < 0 &&
            !data.writes)
                return -1;

        return data.writes;
}

/* Wrapper around pet_expr_update_domain
 * for use as a pet_tree_map_expr callback.
 */
static __isl_give pet_expr *update_domain(__isl_take pet_expr *expr, void *user)
{
        isl_multi_pw_aff *update = user;

        return pet_expr_update_domain(expr, isl_multi_pw_aff_copy(update));
}

/* Modify all access relations in "tree" by precomposing them with
 * the given iteration space transformation.
 */
__isl_give pet_tree *pet_tree_update_domain(__isl_take pet_tree *tree,
        __isl_take isl_multi_pw_aff *update)
{
        tree = pet_tree_map_expr(tree, &update_domain, update);
        isl_multi_pw_aff_free(update);
        return tree;
}

/* Does "tree" contain a continue node (not contained in any loop
 * subtree of "tree"?
 */
int pet_tree_has_continue(__isl_keep pet_tree *tree)
{
        int i;
        int found;

        if (!tree)
                return -1;

        switch (tree->type) {
        case pet_tree_error:
                return -1;
        case pet_tree_continue:
                return 1;
        case pet_tree_break:
        case pet_tree_decl:
        case pet_tree_decl_init:
        case pet_tree_expr:
        case pet_tree_for:
        case pet_tree_while:
        case pet_tree_infinite_loop:
                return 0;
        case pet_tree_block:
                for (i = 0; i < tree->u.b.n; ++i) {
                        found = pet_tree_has_continue(tree->u.b.child[i]);
                        if (found < 0 || found)
                                return found;
                }
                return 0;
        case pet_tree_if:
                return pet_tree_has_continue(tree->u.i.then_body);
        case pet_tree_if_else:
                found = pet_tree_has_continue(tree->u.i.then_body);
                if (found < 0 || found)
                        return found;
                return pet_tree_has_continue(tree->u.i.else_body);
        }
}

static void print_indent(int indent)
{
        fprintf(stderr, "%*s", indent, "");
}

void pet_tree_dump_with_indent(__isl_keep pet_tree *tree, int indent)
{
        int i;

        if (!tree)
                return;

        print_indent(indent);
        fprintf(stderr, "%s\n", pet_tree_type_str(tree->type));
        print_indent(indent);
        fprintf(stderr, "line: %d\n", pet_loc_get_line(tree->loc));
        print_indent(indent);
        fprintf(stderr, "start: %d\n", pet_loc_get_start(tree->loc));
        print_indent(indent);
        fprintf(stderr, "end: %d\n", pet_loc_get_end(tree->loc));
        if (tree->label) {
                print_indent(indent);
                fprintf(stderr, "end: ");
                isl_id_dump(tree->label);
        }
        switch (tree->type) {
        case pet_tree_block:
                print_indent(indent);
                fprintf(stderr, "block: %d\n", tree->u.b.block);
                for (i = 0; i < tree->u.b.n; ++i)
                        pet_tree_dump_with_indent(tree->u.b.child[i],
                                                        indent + 2);
                break;
        case pet_tree_expr:
                pet_expr_dump_with_indent(tree->u.e.expr, indent);
                break;
        case pet_tree_break:
        case pet_tree_continue:
                break;
        case pet_tree_decl:
        case pet_tree_decl_init:
                print_indent(indent);
                fprintf(stderr, "var:\n");
                pet_expr_dump_with_indent(tree->u.d.var, indent + 2);
                if (tree->type != pet_tree_decl_init)
                        break;
                print_indent(indent);
                fprintf(stderr, "init:\n");
                pet_expr_dump_with_indent(tree->u.d.init, indent + 2);
                break;
        case pet_tree_if:
        case pet_tree_if_else:
                print_indent(indent);
                fprintf(stderr, "condition:\n");
                pet_expr_dump_with_indent(tree->u.i.cond, indent + 2);
                print_indent(indent);
                fprintf(stderr, "then:\n");
                pet_tree_dump_with_indent(tree->u.i.then_body, indent + 2);
                if (tree->type != pet_tree_if_else)
                        break;
                print_indent(indent);
                fprintf(stderr, "else:\n");
                pet_tree_dump_with_indent(tree->u.i.else_body, indent + 2);
                break;
        case pet_tree_for:
                print_indent(indent);
                fprintf(stderr, "declared: %d\n", tree->u.l.declared);
                print_indent(indent);
                fprintf(stderr, "var:\n");
                pet_expr_dump_with_indent(tree->u.l.iv, indent + 2);
                print_indent(indent);
                fprintf(stderr, "init:\n");
                pet_expr_dump_with_indent(tree->u.l.init, indent + 2);
                print_indent(indent);
                fprintf(stderr, "inc:\n");
                pet_expr_dump_with_indent(tree->u.l.inc, indent + 2);
        case pet_tree_while:
                print_indent(indent);
                fprintf(stderr, "condition:\n");
                pet_expr_dump_with_indent(tree->u.l.cond, indent + 2);
        case pet_tree_infinite_loop:
                print_indent(indent);
                fprintf(stderr, "body:\n");
                pet_tree_dump_with_indent(tree->u.l.body, indent + 2);
                break;
        case pet_tree_error:
                print_indent(indent);
                fprintf(stderr, "ERROR\n");
                break;
        }
}

void pet_tree_dump(__isl_keep pet_tree *tree)
{
        pet_tree_dump_with_indent(tree, 0);
}