isl_ast_graft_list_extract_hoistable_guard: handle call outside band

[isl.git] / isl_ast.c

/*
 * Copyright 2012-2013 Ecole Normale Superieure
 *
 * Use of this software is governed by the MIT license
 *
 * Written by Sven Verdoolaege,
 * Ecole Normale Superieure, 45 rue d’Ulm, 75230 Paris, France
 */

#include <isl_ast_private.h>

#undef BASE
#define BASE ast_expr

#include <isl_list_templ.c>

#undef BASE
#define BASE ast_node

#include <isl_list_templ.c>

isl_ctx *isl_ast_print_options_get_ctx(
        __isl_keep isl_ast_print_options *options)
{
        return options ? options->ctx : NULL;
}

__isl_give isl_ast_print_options *isl_ast_print_options_alloc(isl_ctx *ctx)
{
        isl_ast_print_options *options;

        options = isl_calloc_type(ctx, isl_ast_print_options);
        if (!options)
                return NULL;

        options->ctx = ctx;
        isl_ctx_ref(ctx);
        options->ref = 1;

        return options;
}

__isl_give isl_ast_print_options *isl_ast_print_options_dup(
        __isl_keep isl_ast_print_options *options)
{
        isl_ctx *ctx;
        isl_ast_print_options *dup;

        if (!options)
                return NULL;

        ctx = isl_ast_print_options_get_ctx(options);
        dup = isl_ast_print_options_alloc(ctx);
        if (!dup)
                return NULL;

        dup->print_for = options->print_for;
        dup->print_for_user = options->print_for_user;
        dup->print_user = options->print_user;
        dup->print_user_user = options->print_user_user;

        return dup;
}

__isl_give isl_ast_print_options *isl_ast_print_options_cow(
        __isl_take isl_ast_print_options *options)
{
        if (!options)
                return NULL;

        if (options->ref == 1)
                return options;
        options->ref--;
        return isl_ast_print_options_dup(options);
}

__isl_give isl_ast_print_options *isl_ast_print_options_copy(
        __isl_keep isl_ast_print_options *options)
{
        if (!options)
                return NULL;

        options->ref++;
        return options;
}

__isl_null isl_ast_print_options *isl_ast_print_options_free(
        __isl_take isl_ast_print_options *options)
{
        if (!options)
                return NULL;

        if (--options->ref > 0)
                return NULL;

        isl_ctx_deref(options->ctx);

        free(options);
        return NULL;
}

/* Set the print_user callback of "options" to "print_user".
 *
 * If this callback is set, then it used to print user nodes in the AST.
 * Otherwise, the expression associated to the user node is printed.
 */
__isl_give isl_ast_print_options *isl_ast_print_options_set_print_user(
        __isl_take isl_ast_print_options *options,
        __isl_give isl_printer *(*print_user)(__isl_take isl_printer *p,
                __isl_take isl_ast_print_options *options,
                __isl_keep isl_ast_node *node, void *user),
        void *user)
{
        options = isl_ast_print_options_cow(options);
        if (!options)
                return NULL;

        options->print_user = print_user;
        options->print_user_user = user;

        return options;
}

/* Set the print_for callback of "options" to "print_for".
 *
 * If this callback is set, then it used to print for nodes in the AST.
 */
__isl_give isl_ast_print_options *isl_ast_print_options_set_print_for(
        __isl_take isl_ast_print_options *options,
        __isl_give isl_printer *(*print_for)(__isl_take isl_printer *p,
                __isl_take isl_ast_print_options *options,
                __isl_keep isl_ast_node *node, void *user),
        void *user)
{
        options = isl_ast_print_options_cow(options);
        if (!options)
                return NULL;

        options->print_for = print_for;
        options->print_for_user = user;

        return options;
}

__isl_give isl_ast_expr *isl_ast_expr_copy(__isl_keep isl_ast_expr *expr)
{
        if (!expr)
                return NULL;

        expr->ref++;
        return expr;
}

__isl_give isl_ast_expr *isl_ast_expr_dup(__isl_keep isl_ast_expr *expr)
{
        int i;
        isl_ctx *ctx;
        isl_ast_expr *dup;

        if (!expr)
                return NULL;

        ctx = isl_ast_expr_get_ctx(expr);
        switch (expr->type) {
        case isl_ast_expr_int:
                dup = isl_ast_expr_from_val(isl_val_copy(expr->u.v));
                break;
        case isl_ast_expr_id:
                dup = isl_ast_expr_from_id(isl_id_copy(expr->u.id));
                break;
        case isl_ast_expr_op:
                dup = isl_ast_expr_alloc_op(ctx,
                                            expr->u.op.op, expr->u.op.n_arg);
                if (!dup)
                        return NULL;
                for (i = 0; i < expr->u.op.n_arg; ++i)
                        dup->u.op.args[i] =
                                isl_ast_expr_copy(expr->u.op.args[i]);
                break;
        case isl_ast_expr_error:
                dup = NULL;
        }

        if (!dup)
                return NULL;

        return dup;
}

__isl_give isl_ast_expr *isl_ast_expr_cow(__isl_take isl_ast_expr *expr)
{
        if (!expr)
                return NULL;

        if (expr->ref == 1)
                return expr;
        expr->ref--;
        return isl_ast_expr_dup(expr);
}

__isl_null isl_ast_expr *isl_ast_expr_free(__isl_take isl_ast_expr *expr)
{
        int i;

        if (!expr)
                return NULL;

        if (--expr->ref > 0)
                return NULL;

        isl_ctx_deref(expr->ctx);

        switch (expr->type) {
        case isl_ast_expr_int:
                isl_val_free(expr->u.v);
                break;
        case isl_ast_expr_id:
                isl_id_free(expr->u.id);
                break;
        case isl_ast_expr_op:
                if (expr->u.op.args)
                        for (i = 0; i < expr->u.op.n_arg; ++i)
                                isl_ast_expr_free(expr->u.op.args[i]);
                free(expr->u.op.args);
                break;
        case isl_ast_expr_error:
                break;
        }

        free(expr);
        return NULL;
}

isl_ctx *isl_ast_expr_get_ctx(__isl_keep isl_ast_expr *expr)
{
        return expr ? expr->ctx : NULL;
}

enum isl_ast_expr_type isl_ast_expr_get_type(__isl_keep isl_ast_expr *expr)
{
        return expr ? expr->type : isl_ast_expr_error;
}

/* Return the integer value represented by "expr".
 */
__isl_give isl_val *isl_ast_expr_get_val(__isl_keep isl_ast_expr *expr)
{
        if (!expr)
                return NULL;
        if (expr->type != isl_ast_expr_int)
                isl_die(isl_ast_expr_get_ctx(expr), isl_error_invalid,
                        "expression not an int", return NULL);
        return isl_val_copy(expr->u.v);
}

__isl_give isl_id *isl_ast_expr_get_id(__isl_keep isl_ast_expr *expr)
{
        if (!expr)
                return NULL;
        if (expr->type != isl_ast_expr_id)
                isl_die(isl_ast_expr_get_ctx(expr), isl_error_invalid,
                        "expression not an identifier", return NULL);

        return isl_id_copy(expr->u.id);
}

enum isl_ast_op_type isl_ast_expr_get_op_type(__isl_keep isl_ast_expr *expr)
{
        if (!expr)
                return isl_ast_op_error;
        if (expr->type != isl_ast_expr_op)
                isl_die(isl_ast_expr_get_ctx(expr), isl_error_invalid,
                        "expression not an operation", return isl_ast_op_error);
        return expr->u.op.op;
}

int isl_ast_expr_get_op_n_arg(__isl_keep isl_ast_expr *expr)
{
        if (!expr)
                return -1;
        if (expr->type != isl_ast_expr_op)
                isl_die(isl_ast_expr_get_ctx(expr), isl_error_invalid,
                        "expression not an operation", return -1);
        return expr->u.op.n_arg;
}

__isl_give isl_ast_expr *isl_ast_expr_get_op_arg(__isl_keep isl_ast_expr *expr,
        int pos)
{
        if (!expr)
                return NULL;
        if (expr->type != isl_ast_expr_op)
                isl_die(isl_ast_expr_get_ctx(expr), isl_error_invalid,
                        "expression not an operation", return NULL);
        if (pos < 0 || pos >= expr->u.op.n_arg)
                isl_die(isl_ast_expr_get_ctx(expr), isl_error_invalid,
                        "index out of bounds", return NULL);

        return isl_ast_expr_copy(expr->u.op.args[pos]);
}

/* Replace the argument at position "pos" of "expr" by "arg".
 */
__isl_give isl_ast_expr *isl_ast_expr_set_op_arg(__isl_take isl_ast_expr *expr,
        int pos, __isl_take isl_ast_expr *arg)
{
        expr = isl_ast_expr_cow(expr);
        if (!expr || !arg)
                goto error;
        if (expr->type != isl_ast_expr_op)
                isl_die(isl_ast_expr_get_ctx(expr), isl_error_invalid,
                        "expression not an operation", goto error);
        if (pos < 0 || pos >= expr->u.op.n_arg)
                isl_die(isl_ast_expr_get_ctx(expr), isl_error_invalid,
                        "index out of bounds", goto error);

        isl_ast_expr_free(expr->u.op.args[pos]);
        expr->u.op.args[pos] = arg;

        return expr;
error:
        isl_ast_expr_free(arg);
        return isl_ast_expr_free(expr);
}

/* Is "expr1" equal to "expr2"?
 */
int isl_ast_expr_is_equal(__isl_keep isl_ast_expr *expr1,
        __isl_keep isl_ast_expr *expr2)
{
        int i;

        if (!expr1 || !expr2)
                return -1;

        if (expr1 == expr2)
                return 1;
        if (expr1->type != expr2->type)
                return 0;
        switch (expr1->type) {
        case isl_ast_expr_int:
                return isl_val_eq(expr1->u.v, expr2->u.v);
        case isl_ast_expr_id:
                return expr1->u.id == expr2->u.id;
        case isl_ast_expr_op:
                if (expr1->u.op.op != expr2->u.op.op)
                        return 0;
                if (expr1->u.op.n_arg != expr2->u.op.n_arg)
                        return 0;
                for (i = 0; i < expr1->u.op.n_arg; ++i) {
                        int equal;
                        equal = isl_ast_expr_is_equal(expr1->u.op.args[i],
                                                        expr2->u.op.args[i]);
                        if (equal < 0 || !equal)
                                return equal;
                }
                return 1;
        case isl_ast_expr_error:
                return -1;
        }
}

/* Create a new operation expression of operation type "op",
 * with "n_arg" as yet unspecified arguments.
 */
__isl_give isl_ast_expr *isl_ast_expr_alloc_op(isl_ctx *ctx,
        enum isl_ast_op_type op, int n_arg)
{
        isl_ast_expr *expr;

        expr = isl_calloc_type(ctx, isl_ast_expr);
        if (!expr)
                return NULL;

        expr->ctx = ctx;
        isl_ctx_ref(ctx);
        expr->ref = 1;
        expr->type = isl_ast_expr_op;
        expr->u.op.op = op;
        expr->u.op.n_arg = n_arg;
        expr->u.op.args = isl_calloc_array(ctx, isl_ast_expr *, n_arg);

        if (n_arg && !expr->u.op.args)
                return isl_ast_expr_free(expr);

        return expr;
}

/* Create a new id expression representing "id".
 */
__isl_give isl_ast_expr *isl_ast_expr_from_id(__isl_take isl_id *id)
{
        isl_ctx *ctx;
        isl_ast_expr *expr;

        if (!id)
                return NULL;

        ctx = isl_id_get_ctx(id);
        expr = isl_calloc_type(ctx, isl_ast_expr);
        if (!expr)
                goto error;

        expr->ctx = ctx;
        isl_ctx_ref(ctx);
        expr->ref = 1;
        expr->type = isl_ast_expr_id;
        expr->u.id = id;

        return expr;
error:
        isl_id_free(id);
        return NULL;
}

/* Create a new integer expression representing "i".
 */
__isl_give isl_ast_expr *isl_ast_expr_alloc_int_si(isl_ctx *ctx, int i)
{
        isl_ast_expr *expr;

        expr = isl_calloc_type(ctx, isl_ast_expr);
        if (!expr)
                return NULL;

        expr->ctx = ctx;
        isl_ctx_ref(ctx);
        expr->ref = 1;
        expr->type = isl_ast_expr_int;
        expr->u.v = isl_val_int_from_si(ctx, i);
        if (!expr->u.v)
                return isl_ast_expr_free(expr);

        return expr;
}

/* Create a new integer expression representing "v".
 */
__isl_give isl_ast_expr *isl_ast_expr_from_val(__isl_take isl_val *v)
{
        isl_ctx *ctx;
        isl_ast_expr *expr;

        if (!v)
                return NULL;
        if (!isl_val_is_int(v))
                isl_die(isl_val_get_ctx(v), isl_error_invalid,
                        "expecting integer value", goto error);

        ctx = isl_val_get_ctx(v);
        expr = isl_calloc_type(ctx, isl_ast_expr);
        if (!expr)
                goto error;

        expr->ctx = ctx;
        isl_ctx_ref(ctx);
        expr->ref = 1;
        expr->type = isl_ast_expr_int;
        expr->u.v = v;

        return expr;
error:
        isl_val_free(v);
        return NULL;
}

/* Create an expression representing the unary operation "type" applied to
 * "arg".
 */
__isl_give isl_ast_expr *isl_ast_expr_alloc_unary(enum isl_ast_op_type type,
        __isl_take isl_ast_expr *arg)
{
        isl_ctx *ctx;
        isl_ast_expr *expr = NULL;

        if (!arg)
                return NULL;

        ctx = isl_ast_expr_get_ctx(arg);
        expr = isl_ast_expr_alloc_op(ctx, type, 1);
        if (!expr)
                goto error;

        expr->u.op.args[0] = arg;

        return expr;
error:
        isl_ast_expr_free(arg);
        return NULL;
}

/* Create an expression representing the negation of "arg".
 */
__isl_give isl_ast_expr *isl_ast_expr_neg(__isl_take isl_ast_expr *arg)
{
        return isl_ast_expr_alloc_unary(isl_ast_op_minus, arg);
}

/* Create an expression representing the address of "expr".
 */
__isl_give isl_ast_expr *isl_ast_expr_address_of(__isl_take isl_ast_expr *expr)
{
        if (!expr)
                return NULL;

        if (isl_ast_expr_get_type(expr) != isl_ast_expr_op ||
            isl_ast_expr_get_op_type(expr) != isl_ast_op_access)
                isl_die(isl_ast_expr_get_ctx(expr), isl_error_invalid,
                        "can only take address of access expressions",
                        return isl_ast_expr_free(expr));

        return isl_ast_expr_alloc_unary(isl_ast_op_address_of, expr);
}

/* Create an expression representing the binary operation "type"
 * applied to "expr1" and "expr2".
 */
__isl_give isl_ast_expr *isl_ast_expr_alloc_binary(enum isl_ast_op_type type,
        __isl_take isl_ast_expr *expr1, __isl_take isl_ast_expr *expr2)
{
        isl_ctx *ctx;
        isl_ast_expr *expr = NULL;

        if (!expr1 || !expr2)
                goto error;

        ctx = isl_ast_expr_get_ctx(expr1);
        expr = isl_ast_expr_alloc_op(ctx, type, 2);
        if (!expr)
                goto error;

        expr->u.op.args[0] = expr1;
        expr->u.op.args[1] = expr2;

        return expr;
error:
        isl_ast_expr_free(expr1);
        isl_ast_expr_free(expr2);
        return NULL;
}

/* Create an expression representing the sum of "expr1" and "expr2".
 */
__isl_give isl_ast_expr *isl_ast_expr_add(__isl_take isl_ast_expr *expr1,
        __isl_take isl_ast_expr *expr2)
{
        return isl_ast_expr_alloc_binary(isl_ast_op_add, expr1, expr2);
}

/* Create an expression representing the difference of "expr1" and "expr2".
 */
__isl_give isl_ast_expr *isl_ast_expr_sub(__isl_take isl_ast_expr *expr1,
        __isl_take isl_ast_expr *expr2)
{
        return isl_ast_expr_alloc_binary(isl_ast_op_sub, expr1, expr2);
}

/* Create an expression representing the product of "expr1" and "expr2".
 */
__isl_give isl_ast_expr *isl_ast_expr_mul(__isl_take isl_ast_expr *expr1,
        __isl_take isl_ast_expr *expr2)
{
        return isl_ast_expr_alloc_binary(isl_ast_op_mul, expr1, expr2);
}

/* Create an expression representing the quotient of "expr1" and "expr2".
 */
__isl_give isl_ast_expr *isl_ast_expr_div(__isl_take isl_ast_expr *expr1,
        __isl_take isl_ast_expr *expr2)
{
        return isl_ast_expr_alloc_binary(isl_ast_op_div, expr1, expr2);
}

/* Create an expression representing the quotient of the integer
 * division of "expr1" by "expr2", where "expr1" is known to be
 * non-negative.
 */
__isl_give isl_ast_expr *isl_ast_expr_pdiv_q(__isl_take isl_ast_expr *expr1,
        __isl_take isl_ast_expr *expr2)
{
        return isl_ast_expr_alloc_binary(isl_ast_op_pdiv_q, expr1, expr2);
}

/* Create an expression representing the remainder of the integer
 * division of "expr1" by "expr2", where "expr1" is known to be
 * non-negative.
 */
__isl_give isl_ast_expr *isl_ast_expr_pdiv_r(__isl_take isl_ast_expr *expr1,
        __isl_take isl_ast_expr *expr2)
{
        return isl_ast_expr_alloc_binary(isl_ast_op_pdiv_r, expr1, expr2);
}

/* Create an expression representing the conjunction of "expr1" and "expr2".
 */
__isl_give isl_ast_expr *isl_ast_expr_and(__isl_take isl_ast_expr *expr1,
        __isl_take isl_ast_expr *expr2)
{
        return isl_ast_expr_alloc_binary(isl_ast_op_and, expr1, expr2);
}

/* Create an expression representing the conjunction of "expr1" and "expr2",
 * where "expr2" is evaluated only if "expr1" is evaluated to true.
 */
__isl_give isl_ast_expr *isl_ast_expr_and_then(__isl_take isl_ast_expr *expr1,
        __isl_take isl_ast_expr *expr2)
{
        return isl_ast_expr_alloc_binary(isl_ast_op_and_then, expr1, expr2);
}

/* Create an expression representing the disjunction of "expr1" and "expr2".
 */
__isl_give isl_ast_expr *isl_ast_expr_or(__isl_take isl_ast_expr *expr1,
        __isl_take isl_ast_expr *expr2)
{
        return isl_ast_expr_alloc_binary(isl_ast_op_or, expr1, expr2);
}

/* Create an expression representing the disjunction of "expr1" and "expr2",
 * where "expr2" is evaluated only if "expr1" is evaluated to false.
 */
__isl_give isl_ast_expr *isl_ast_expr_or_else(__isl_take isl_ast_expr *expr1,
        __isl_take isl_ast_expr *expr2)
{
        return isl_ast_expr_alloc_binary(isl_ast_op_or_else, expr1, expr2);
}

/* Create an expression representing "expr1" less than or equal to "expr2".
 */
__isl_give isl_ast_expr *isl_ast_expr_le(__isl_take isl_ast_expr *expr1,
        __isl_take isl_ast_expr *expr2)
{
        return isl_ast_expr_alloc_binary(isl_ast_op_le, expr1, expr2);
}

/* Create an expression representing "expr1" less than "expr2".
 */
__isl_give isl_ast_expr *isl_ast_expr_lt(__isl_take isl_ast_expr *expr1,
        __isl_take isl_ast_expr *expr2)
{
        return isl_ast_expr_alloc_binary(isl_ast_op_lt, expr1, expr2);
}

/* Create an expression representing "expr1" greater than or equal to "expr2".
 */
__isl_give isl_ast_expr *isl_ast_expr_ge(__isl_take isl_ast_expr *expr1,
        __isl_take isl_ast_expr *expr2)
{
        return isl_ast_expr_alloc_binary(isl_ast_op_ge, expr1, expr2);
}

/* Create an expression representing "expr1" greater than "expr2".
 */
__isl_give isl_ast_expr *isl_ast_expr_gt(__isl_take isl_ast_expr *expr1,
        __isl_take isl_ast_expr *expr2)
{
        return isl_ast_expr_alloc_binary(isl_ast_op_gt, expr1, expr2);
}

/* Create an expression representing "expr1" equal to "expr2".
 */
__isl_give isl_ast_expr *isl_ast_expr_eq(__isl_take isl_ast_expr *expr1,
        __isl_take isl_ast_expr *expr2)
{
        return isl_ast_expr_alloc_binary(isl_ast_op_eq, expr1, expr2);
}

/* Create an expression of type "type" with as arguments "arg0" followed
 * by "arguments".
 */
static __isl_give isl_ast_expr *ast_expr_with_arguments(
        enum isl_ast_op_type type, __isl_take isl_ast_expr *arg0,
        __isl_take isl_ast_expr_list *arguments)
{
        int i, n;
        isl_ctx *ctx;
        isl_ast_expr *res = NULL;

        if (!arg0 || !arguments)
                goto error;

        ctx = isl_ast_expr_get_ctx(arg0);
        n = isl_ast_expr_list_n_ast_expr(arguments);
        res = isl_ast_expr_alloc_op(ctx, type, 1 + n);
        if (!res)
                goto error;
        for (i = 0; i < n; ++i) {
                isl_ast_expr *arg;
                arg = isl_ast_expr_list_get_ast_expr(arguments, i);
                res->u.op.args[1 + i] = arg;
                if (!arg)
                        goto error;
        }
        res->u.op.args[0] = arg0;

        isl_ast_expr_list_free(arguments);
        return res;
error:
        isl_ast_expr_free(arg0);
        isl_ast_expr_list_free(arguments);
        isl_ast_expr_free(res);
        return NULL;
}

/* Create an expression representing an access to "array" with index
 * expressions "indices".
 */
__isl_give isl_ast_expr *isl_ast_expr_access(__isl_take isl_ast_expr *array,
        __isl_take isl_ast_expr_list *indices)
{
        return ast_expr_with_arguments(isl_ast_op_access, array, indices);
}

/* Create an expression representing a call to "function" with argument
 * expressions "arguments".
 */
__isl_give isl_ast_expr *isl_ast_expr_call(__isl_take isl_ast_expr *function,
        __isl_take isl_ast_expr_list *arguments)
{
        return ast_expr_with_arguments(isl_ast_op_call, function, arguments);
}

/* For each subexpression of "expr" of type isl_ast_expr_id,
 * if it appears in "id2expr", then replace it by the corresponding
 * expression.
 */
__isl_give isl_ast_expr *isl_ast_expr_substitute_ids(
        __isl_take isl_ast_expr *expr, __isl_take isl_id_to_ast_expr *id2expr)
{
        int i;
        isl_id *id;

        if (!expr || !id2expr)
                goto error;

        switch (expr->type) {
        case isl_ast_expr_int:
                break;
        case isl_ast_expr_id:
                if (!isl_id_to_ast_expr_has(id2expr, expr->u.id))
                        break;
                id = isl_id_copy(expr->u.id);
                isl_ast_expr_free(expr);
                expr = isl_id_to_ast_expr_get(id2expr, id);
                break;
        case isl_ast_expr_op:
                for (i = 0; i < expr->u.op.n_arg; ++i) {
                        isl_ast_expr *arg;
                        arg = isl_ast_expr_copy(expr->u.op.args[i]);
                        arg = isl_ast_expr_substitute_ids(arg,
                                            isl_id_to_ast_expr_copy(id2expr));
                        if (arg == expr->u.op.args[i]) {
                                isl_ast_expr_free(arg);
                                continue;
                        }
                        if (!arg)
                                expr = isl_ast_expr_free(expr);
                        expr = isl_ast_expr_cow(expr);
                        if (!expr) {
                                isl_ast_expr_free(arg);
                                break;
                        }
                        isl_ast_expr_free(expr->u.op.args[i]);
                        expr->u.op.args[i] = arg;
                }
                break;
        case isl_ast_expr_error:
                expr = isl_ast_expr_free(expr);
                break;
        }

        isl_id_to_ast_expr_free(id2expr);
        return expr;
error:
        isl_ast_expr_free(expr);
        isl_id_to_ast_expr_free(id2expr);
        return NULL;
}

isl_ctx *isl_ast_node_get_ctx(__isl_keep isl_ast_node *node)
{
        return node ? node->ctx : NULL;
}

enum isl_ast_node_type isl_ast_node_get_type(__isl_keep isl_ast_node *node)
{
        return node ? node->type : isl_ast_node_error;
}

__isl_give isl_ast_node *isl_ast_node_alloc(isl_ctx *ctx,
        enum isl_ast_node_type type)
{
        isl_ast_node *node;

        node = isl_calloc_type(ctx, isl_ast_node);
        if (!node)
                return NULL;

        node->ctx = ctx;
        isl_ctx_ref(ctx);
        node->ref = 1;
        node->type = type;

        return node;
}

/* Create an if node with the given guard.
 *
 * The then body needs to be filled in later.
 */
__isl_give isl_ast_node *isl_ast_node_alloc_if(__isl_take isl_ast_expr *guard)
{
        isl_ast_node *node;

        if (!guard)
                return NULL;

        node = isl_ast_node_alloc(isl_ast_expr_get_ctx(guard), isl_ast_node_if);
        if (!node)
                goto error;
        node->u.i.guard = guard;

        return node;
error:
        isl_ast_expr_free(guard);
        return NULL;
}

/* Create a for node with the given iterator.
 *
 * The remaining fields need to be filled in later.
 */
__isl_give isl_ast_node *isl_ast_node_alloc_for(__isl_take isl_id *id)
{
        isl_ast_node *node;
        isl_ctx *ctx;

        if (!id)
                return NULL;

        ctx = isl_id_get_ctx(id);
        node = isl_ast_node_alloc(ctx, isl_ast_node_for);
        if (!node)
                goto error;

        node->u.f.iterator = isl_ast_expr_from_id(id);
        if (!node->u.f.iterator)
                return isl_ast_node_free(node);

        return node;
error:
        isl_id_free(id);
        return NULL;
}

/* Create a user node evaluating "expr".
 */
__isl_give isl_ast_node *isl_ast_node_alloc_user(__isl_take isl_ast_expr *expr)
{
        isl_ctx *ctx;
        isl_ast_node *node;

        if (!expr)
                return NULL;

        ctx = isl_ast_expr_get_ctx(expr);
        node = isl_ast_node_alloc(ctx, isl_ast_node_user);
        if (!node)
                goto error;

        node->u.e.expr = expr;

        return node;
error:
        isl_ast_expr_free(expr);
        return NULL;
}

/* Create a block node with the given children.
 */
__isl_give isl_ast_node *isl_ast_node_alloc_block(
        __isl_take isl_ast_node_list *list)
{
        isl_ast_node *node;
        isl_ctx *ctx;

        if (!list)
                return NULL;

        ctx = isl_ast_node_list_get_ctx(list);
        node = isl_ast_node_alloc(ctx, isl_ast_node_block);
        if (!node)
                goto error;

        node->u.b.children = list;

        return node;
error:
        isl_ast_node_list_free(list);
        return NULL;
}

/* Represent the given list of nodes as a single node, either by
 * extract the node from a single element list or by creating
 * a block node with the list of nodes as children.
 */
__isl_give isl_ast_node *isl_ast_node_from_ast_node_list(
        __isl_take isl_ast_node_list *list)
{
        isl_ast_node *node;

        if (isl_ast_node_list_n_ast_node(list) != 1)
                return isl_ast_node_alloc_block(list);

        node = isl_ast_node_list_get_ast_node(list, 0);
        isl_ast_node_list_free(list);

        return node;
}

__isl_give isl_ast_node *isl_ast_node_copy(__isl_keep isl_ast_node *node)
{
        if (!node)
                return NULL;

        node->ref++;
        return node;
}

__isl_give isl_ast_node *isl_ast_node_dup(__isl_keep isl_ast_node *node)
{
        isl_ast_node *dup;

        if (!node)
                return NULL;

        dup = isl_ast_node_alloc(isl_ast_node_get_ctx(node), node->type);
        if (!dup)
                return NULL;

        switch (node->type) {
        case isl_ast_node_if:
                dup->u.i.guard = isl_ast_expr_copy(node->u.i.guard);
                dup->u.i.then = isl_ast_node_copy(node->u.i.then);
                dup->u.i.else_node = isl_ast_node_copy(node->u.i.else_node);
                if (!dup->u.i.guard  || !dup->u.i.then ||
                    (node->u.i.else_node && !dup->u.i.else_node))
                        return isl_ast_node_free(dup);
                break;
        case isl_ast_node_for:
                dup->u.f.iterator = isl_ast_expr_copy(node->u.f.iterator);
                dup->u.f.init = isl_ast_expr_copy(node->u.f.init);
                dup->u.f.cond = isl_ast_expr_copy(node->u.f.cond);
                dup->u.f.inc = isl_ast_expr_copy(node->u.f.inc);
                dup->u.f.body = isl_ast_node_copy(node->u.f.body);
                if (!dup->u.f.iterator || !dup->u.f.init || !dup->u.f.cond ||
                    !dup->u.f.inc || !dup->u.f.body)
                        return isl_ast_node_free(dup);
                break;
        case isl_ast_node_block:
                dup->u.b.children = isl_ast_node_list_copy(node->u.b.children);
                if (!dup->u.b.children)
                        return isl_ast_node_free(dup);
                break;
        case isl_ast_node_user:
                dup->u.e.expr = isl_ast_expr_copy(node->u.e.expr);
                if (!dup->u.e.expr)
                        return isl_ast_node_free(dup);
                break;
        case isl_ast_node_error:
                break;
        }

        return dup;
}

__isl_give isl_ast_node *isl_ast_node_cow(__isl_take isl_ast_node *node)
{
        if (!node)
                return NULL;

        if (node->ref == 1)
                return node;
        node->ref--;
        return isl_ast_node_dup(node);
}

__isl_null isl_ast_node *isl_ast_node_free(__isl_take isl_ast_node *node)
{
        if (!node)
                return NULL;

        if (--node->ref > 0)
                return NULL;

        switch (node->type) {
        case isl_ast_node_if:
                isl_ast_expr_free(node->u.i.guard);
                isl_ast_node_free(node->u.i.then);
                isl_ast_node_free(node->u.i.else_node);
                break;
        case isl_ast_node_for:
                isl_ast_expr_free(node->u.f.iterator);
                isl_ast_expr_free(node->u.f.init);
                isl_ast_expr_free(node->u.f.cond);
                isl_ast_expr_free(node->u.f.inc);
                isl_ast_node_free(node->u.f.body);
                break;
        case isl_ast_node_block:
                isl_ast_node_list_free(node->u.b.children);
                break;
        case isl_ast_node_user:
                isl_ast_expr_free(node->u.e.expr);
                break;
        case isl_ast_node_error:
                break;
        }

        isl_id_free(node->annotation);
        isl_ctx_deref(node->ctx);
        free(node);

        return NULL;
}

/* Replace the body of the for node "node" by "body".
 */
__isl_give isl_ast_node *isl_ast_node_for_set_body(
        __isl_take isl_ast_node *node, __isl_take isl_ast_node *body)
{
        node = isl_ast_node_cow(node);
        if (!node || !body)
                goto error;
        if (node->type != isl_ast_node_for)
                isl_die(isl_ast_node_get_ctx(node), isl_error_invalid,
                        "not a for node", goto error);

        isl_ast_node_free(node->u.f.body);
        node->u.f.body = body;

        return node;
error:
        isl_ast_node_free(node);
        isl_ast_node_free(body);
        return NULL;
}

__isl_give isl_ast_node *isl_ast_node_for_get_body(
        __isl_keep isl_ast_node *node)
{
        if (!node)
                return NULL;
        if (node->type != isl_ast_node_for)
                isl_die(isl_ast_node_get_ctx(node), isl_error_invalid,
                        "not a for node", return NULL);
        return isl_ast_node_copy(node->u.f.body);
}

/* Mark the given for node as being degenerate.
 */
__isl_give isl_ast_node *isl_ast_node_for_mark_degenerate(
        __isl_take isl_ast_node *node)
{
        node = isl_ast_node_cow(node);
        if (!node)
                return NULL;
        node->u.f.degenerate = 1;
        return node;
}

int isl_ast_node_for_is_degenerate(__isl_keep isl_ast_node *node)
{
        if (!node)
                return -1;
        if (node->type != isl_ast_node_for)
                isl_die(isl_ast_node_get_ctx(node), isl_error_invalid,
                        "not a for node", return -1);
        return node->u.f.degenerate;
}

__isl_give isl_ast_expr *isl_ast_node_for_get_iterator(
        __isl_keep isl_ast_node *node)
{
        if (!node)
                return NULL;
        if (node->type != isl_ast_node_for)
                isl_die(isl_ast_node_get_ctx(node), isl_error_invalid,
                        "not a for node", return NULL);
        return isl_ast_expr_copy(node->u.f.iterator);
}

__isl_give isl_ast_expr *isl_ast_node_for_get_init(
        __isl_keep isl_ast_node *node)
{
        if (!node)
                return NULL;
        if (node->type != isl_ast_node_for)
                isl_die(isl_ast_node_get_ctx(node), isl_error_invalid,
                        "not a for node", return NULL);
        return isl_ast_expr_copy(node->u.f.init);
}

/* Return the condition expression of the given for node.
 *
 * If the for node is degenerate, then the condition is not explicitly
 * stored in the node.  Instead, it is constructed as
 *
 *      iterator <= init
 */
__isl_give isl_ast_expr *isl_ast_node_for_get_cond(
        __isl_keep isl_ast_node *node)
{
        if (!node)
                return NULL;
        if (node->type != isl_ast_node_for)
                isl_die(isl_ast_node_get_ctx(node), isl_error_invalid,
                        "not a for node", return NULL);
        if (!node->u.f.degenerate)
                return isl_ast_expr_copy(node->u.f.cond);

        return isl_ast_expr_alloc_binary(isl_ast_op_le,
                                isl_ast_expr_copy(node->u.f.iterator),
                                isl_ast_expr_copy(node->u.f.init));
}

/* Return the increment of the given for node.
 *
 * If the for node is degenerate, then the increment is not explicitly
 * stored in the node.  We simply return "1".
 */
__isl_give isl_ast_expr *isl_ast_node_for_get_inc(
        __isl_keep isl_ast_node *node)
{
        if (!node)
                return NULL;
        if (node->type != isl_ast_node_for)
                isl_die(isl_ast_node_get_ctx(node), isl_error_invalid,
                        "not a for node", return NULL);
        if (!node->u.f.degenerate)
                return isl_ast_expr_copy(node->u.f.inc);
        return isl_ast_expr_alloc_int_si(isl_ast_node_get_ctx(node), 1);
}

/* Replace the then branch of the if node "node" by "child".
 */
__isl_give isl_ast_node *isl_ast_node_if_set_then(
        __isl_take isl_ast_node *node, __isl_take isl_ast_node *child)
{
        node = isl_ast_node_cow(node);
        if (!node || !child)
                goto error;
        if (node->type != isl_ast_node_if)
                isl_die(isl_ast_node_get_ctx(node), isl_error_invalid,
                        "not an if node", goto error);

        isl_ast_node_free(node->u.i.then);
        node->u.i.then = child;

        return node;
error:
        isl_ast_node_free(node);
        isl_ast_node_free(child);
        return NULL;
}

__isl_give isl_ast_node *isl_ast_node_if_get_then(
        __isl_keep isl_ast_node *node)
{
        if (!node)
                return NULL;
        if (node->type != isl_ast_node_if)
                isl_die(isl_ast_node_get_ctx(node), isl_error_invalid,
                        "not an if node", return NULL);
        return isl_ast_node_copy(node->u.i.then);
}

int isl_ast_node_if_has_else(
        __isl_keep isl_ast_node *node)
{
        if (!node)
                return -1;
        if (node->type != isl_ast_node_if)
                isl_die(isl_ast_node_get_ctx(node), isl_error_invalid,
                        "not an if node", return -1);
        return node->u.i.else_node != NULL;
}

__isl_give isl_ast_node *isl_ast_node_if_get_else(
        __isl_keep isl_ast_node *node)
{
        if (!node)
                return NULL;
        if (node->type != isl_ast_node_if)
                isl_die(isl_ast_node_get_ctx(node), isl_error_invalid,
                        "not an if node", return NULL);
        return isl_ast_node_copy(node->u.i.else_node);
}

__isl_give isl_ast_expr *isl_ast_node_if_get_cond(
        __isl_keep isl_ast_node *node)
{
        if (!node)
                return NULL;
        if (node->type != isl_ast_node_if)
                isl_die(isl_ast_node_get_ctx(node), isl_error_invalid,
                        "not a guard node", return NULL);
        return isl_ast_expr_copy(node->u.i.guard);
}

__isl_give isl_ast_node_list *isl_ast_node_block_get_children(
        __isl_keep isl_ast_node *node)
{
        if (!node)
                return NULL;
        if (node->type != isl_ast_node_block)
                isl_die(isl_ast_node_get_ctx(node), isl_error_invalid,
                        "not a block node", return NULL);
        return isl_ast_node_list_copy(node->u.b.children);
}

__isl_give isl_ast_expr *isl_ast_node_user_get_expr(
        __isl_keep isl_ast_node *node)
{
        if (!node)
                return NULL;
        if (node->type != isl_ast_node_user)
                isl_die(isl_ast_node_get_ctx(node), isl_error_invalid,
                        "not a user node", return NULL);

        return isl_ast_expr_copy(node->u.e.expr);
}

__isl_give isl_id *isl_ast_node_get_annotation(__isl_keep isl_ast_node *node)
{
        return node ? isl_id_copy(node->annotation) : NULL;
}

/* Replace node->annotation by "annotation".
 */
__isl_give isl_ast_node *isl_ast_node_set_annotation(
        __isl_take isl_ast_node *node, __isl_take isl_id *annotation)
{
        node = isl_ast_node_cow(node);
        if (!node || !annotation)
                goto error;

        isl_id_free(node->annotation);
        node->annotation = annotation;

        return node;
error:
        isl_id_free(annotation);
        return isl_ast_node_free(node);
}

/* Textual C representation of the various operators.
 */
static char *op_str[] = {
        [isl_ast_op_and] = "&&",
        [isl_ast_op_and_then] = "&&",
        [isl_ast_op_or] = "||",
        [isl_ast_op_or_else] = "||",
        [isl_ast_op_max] = "max",
        [isl_ast_op_min] = "min",
        [isl_ast_op_minus] = "-",
        [isl_ast_op_add] = "+",
        [isl_ast_op_sub] = "-",
        [isl_ast_op_mul] = "*",
        [isl_ast_op_pdiv_q] = "/",
        [isl_ast_op_pdiv_r] = "%",
        [isl_ast_op_zdiv_r] = "%",
        [isl_ast_op_div] = "/",
        [isl_ast_op_eq] = "==",
        [isl_ast_op_le] = "<=",
        [isl_ast_op_ge] = ">=",
        [isl_ast_op_lt] = "<",
        [isl_ast_op_gt] = ">",
        [isl_ast_op_member] = ".",
        [isl_ast_op_address_of] = "&"
};

/* Precedence in C of the various operators.
 * Based on http://en.wikipedia.org/wiki/Operators_in_C_and_C++
 * Lowest value means highest precedence.
 */
static int op_prec[] = {
        [isl_ast_op_and] = 13,
        [isl_ast_op_and_then] = 13,
        [isl_ast_op_or] = 14,
        [isl_ast_op_or_else] = 14,
        [isl_ast_op_max] = 2,
        [isl_ast_op_min] = 2,
        [isl_ast_op_minus] = 3,
        [isl_ast_op_add] = 6,
        [isl_ast_op_sub] = 6,
        [isl_ast_op_mul] = 5,
        [isl_ast_op_div] = 5,
        [isl_ast_op_fdiv_q] = 2,
        [isl_ast_op_pdiv_q] = 5,
        [isl_ast_op_pdiv_r] = 5,
        [isl_ast_op_zdiv_r] = 5,
        [isl_ast_op_cond] = 15,
        [isl_ast_op_select] = 15,
        [isl_ast_op_eq] = 9,
        [isl_ast_op_le] = 8,
        [isl_ast_op_ge] = 8,
        [isl_ast_op_lt] = 8,
        [isl_ast_op_gt] = 8,
        [isl_ast_op_call] = 2,
        [isl_ast_op_access] = 2,
        [isl_ast_op_member] = 2,
        [isl_ast_op_address_of] = 3
};

/* Is the operator left-to-right associative?
 */
static int op_left[] = {
        [isl_ast_op_and] = 1,
        [isl_ast_op_and_then] = 1,
        [isl_ast_op_or] = 1,
        [isl_ast_op_or_else] = 1,
        [isl_ast_op_max] = 1,
        [isl_ast_op_min] = 1,
        [isl_ast_op_minus] = 0,
        [isl_ast_op_add] = 1,
        [isl_ast_op_sub] = 1,
        [isl_ast_op_mul] = 1,
        [isl_ast_op_div] = 1,
        [isl_ast_op_fdiv_q] = 1,
        [isl_ast_op_pdiv_q] = 1,
        [isl_ast_op_pdiv_r] = 1,
        [isl_ast_op_zdiv_r] = 1,
        [isl_ast_op_cond] = 0,
        [isl_ast_op_select] = 0,
        [isl_ast_op_eq] = 1,
        [isl_ast_op_le] = 1,
        [isl_ast_op_ge] = 1,
        [isl_ast_op_lt] = 1,
        [isl_ast_op_gt] = 1,
        [isl_ast_op_call] = 1,
        [isl_ast_op_access] = 1,
        [isl_ast_op_member] = 1,
        [isl_ast_op_address_of] = 0
};

static int is_and(enum isl_ast_op_type op)
{
        return op == isl_ast_op_and || op == isl_ast_op_and_then;
}

static int is_or(enum isl_ast_op_type op)
{
        return op == isl_ast_op_or || op == isl_ast_op_or_else;
}

static int is_add_sub(enum isl_ast_op_type op)
{
        return op == isl_ast_op_add || op == isl_ast_op_sub;
}

static int is_div_mod(enum isl_ast_op_type op)
{
        return op == isl_ast_op_div ||
               op == isl_ast_op_pdiv_r ||
               op == isl_ast_op_zdiv_r;
}

/* Do we need/want parentheses around "expr" as a subexpression of
 * an "op" operation?  If "left" is set, then "expr" is the left-most
 * operand.
 *
 * We only need parentheses if "expr" represents an operation.
 *
 * If op has a higher precedence than expr->u.op.op, then we need
 * parentheses.
 * If op and expr->u.op.op have the same precedence, but the operations
 * are performed in an order that is different from the associativity,
 * then we need parentheses.
 *
 * An and inside an or technically does not require parentheses,
 * but some compilers complain about that, so we add them anyway.
 *
 * Computations such as "a / b * c" and "a % b + c" can be somewhat
 * difficult to read, so we add parentheses for those as well.
 */
static int sub_expr_need_parens(enum isl_ast_op_type op,
        __isl_keep isl_ast_expr *expr, int left)
{
        if (expr->type != isl_ast_expr_op)
                return 0;

        if (op_prec[expr->u.op.op] > op_prec[op])
                return 1;
        if (op_prec[expr->u.op.op] == op_prec[op] && left != op_left[op])
                return 1;

        if (is_or(op) && is_and(expr->u.op.op))
                return 1;
        if (op == isl_ast_op_mul && expr->u.op.op != isl_ast_op_mul &&
            op_prec[expr->u.op.op] == op_prec[op])
                return 1;
        if (is_add_sub(op) && is_div_mod(expr->u.op.op))
                return 1;

        return 0;
}

/* Print "expr" as a subexpression of an "op" operation.
 * If "left" is set, then "expr" is the left-most operand.
 */
static __isl_give isl_printer *print_sub_expr(__isl_take isl_printer *p,
        enum isl_ast_op_type op, __isl_keep isl_ast_expr *expr, int left)
{
        int need_parens;

        need_parens = sub_expr_need_parens(op, expr, left);

        if (need_parens)
                p = isl_printer_print_str(p, "(");
        p = isl_printer_print_ast_expr(p, expr);
        if (need_parens)
                p = isl_printer_print_str(p, ")");
        return p;
}

/* Print a min or max reduction "expr".
 */
static __isl_give isl_printer *print_min_max(__isl_take isl_printer *p,
        __isl_keep isl_ast_expr *expr)
{
        int i = 0;

        for (i = 1; i < expr->u.op.n_arg; ++i) {
                p = isl_printer_print_str(p, op_str[expr->u.op.op]);
                p = isl_printer_print_str(p, "(");
        }
        p = isl_printer_print_ast_expr(p, expr->u.op.args[0]);
        for (i = 1; i < expr->u.op.n_arg; ++i) {
                p = isl_printer_print_str(p, ", ");
                p = isl_printer_print_ast_expr(p, expr->u.op.args[i]);
                p = isl_printer_print_str(p, ")");
        }

        return p;
}

/* Print a function call "expr".
 *
 * The first argument represents the function to be called.
 */
static __isl_give isl_printer *print_call(__isl_take isl_printer *p,
        __isl_keep isl_ast_expr *expr)
{
        int i = 0;

        p = isl_printer_print_ast_expr(p, expr->u.op.args[0]);
        p = isl_printer_print_str(p, "(");
        for (i = 1; i < expr->u.op.n_arg; ++i) {
                if (i != 1)
                        p = isl_printer_print_str(p, ", ");
                p = isl_printer_print_ast_expr(p, expr->u.op.args[i]);
        }
        p = isl_printer_print_str(p, ")");

        return p;
}

/* Print an array access "expr".
 *
 * The first argument represents the array being accessed.
 */
static __isl_give isl_printer *print_access(__isl_take isl_printer *p,
        __isl_keep isl_ast_expr *expr)
{
        int i = 0;

        p = isl_printer_print_ast_expr(p, expr->u.op.args[0]);
        for (i = 1; i < expr->u.op.n_arg; ++i) {
                p = isl_printer_print_str(p, "[");
                p = isl_printer_print_ast_expr(p, expr->u.op.args[i]);
                p = isl_printer_print_str(p, "]");
        }

        return p;
}

/* Print "expr" to "p".
 *
 * If we are printing in isl format, then we also print an indication
 * of the size of the expression (if it was computed).
 */
__isl_give isl_printer *isl_printer_print_ast_expr(__isl_take isl_printer *p,
        __isl_keep isl_ast_expr *expr)
{
        if (!p)
                return NULL;
        if (!expr)
                return isl_printer_free(p);

        switch (expr->type) {
        case isl_ast_expr_op:
                if (expr->u.op.op == isl_ast_op_call) {
                        p = print_call(p, expr);
                        break;
                }
                if (expr->u.op.op == isl_ast_op_access) {
                        p = print_access(p, expr);
                        break;
                }
                if (expr->u.op.n_arg == 1) {
                        p = isl_printer_print_str(p, op_str[expr->u.op.op]);
                        p = print_sub_expr(p, expr->u.op.op,
                                                expr->u.op.args[0], 0);
                        break;
                }
                if (expr->u.op.op == isl_ast_op_fdiv_q) {
                        p = isl_printer_print_str(p, "floord(");
                        p = isl_printer_print_ast_expr(p, expr->u.op.args[0]);
                        p = isl_printer_print_str(p, ", ");
                        p = isl_printer_print_ast_expr(p, expr->u.op.args[1]);
                        p = isl_printer_print_str(p, ")");
                        break;
                }
                if (expr->u.op.op == isl_ast_op_max ||
                    expr->u.op.op == isl_ast_op_min) {
                        p = print_min_max(p, expr);
                        break;
                }
                if (expr->u.op.op == isl_ast_op_cond ||
                    expr->u.op.op == isl_ast_op_select) {
                        p = isl_printer_print_ast_expr(p, expr->u.op.args[0]);
                        p = isl_printer_print_str(p, " ? ");
                        p = isl_printer_print_ast_expr(p, expr->u.op.args[1]);
                        p = isl_printer_print_str(p, " : ");
                        p = isl_printer_print_ast_expr(p, expr->u.op.args[2]);
                        break;
                }
                if (expr->u.op.n_arg != 2)
                        isl_die(isl_printer_get_ctx(p), isl_error_internal,
                                "operation should have two arguments",
                                goto error);
                p = print_sub_expr(p, expr->u.op.op, expr->u.op.args[0], 1);
                if (expr->u.op.op != isl_ast_op_member)
                        p = isl_printer_print_str(p, " ");
                p = isl_printer_print_str(p, op_str[expr->u.op.op]);
                if (expr->u.op.op != isl_ast_op_member)
                        p = isl_printer_print_str(p, " ");
                p = print_sub_expr(p, expr->u.op.op, expr->u.op.args[1], 0);
                break;
        case isl_ast_expr_id:
                p = isl_printer_print_str(p, isl_id_get_name(expr->u.id));
                break;
        case isl_ast_expr_int:
                p = isl_printer_print_val(p, expr->u.v);
                break;
        case isl_ast_expr_error:
                break;
        }

        return p;
error:
        isl_printer_free(p);
        return NULL;
}

/* Print "node" to "p" in "isl format".
 */
static __isl_give isl_printer *print_ast_node_isl(__isl_take isl_printer *p,
        __isl_keep isl_ast_node *node)
{
        p = isl_printer_print_str(p, "(");
        switch (node->type) {
        case isl_ast_node_for:
                if (node->u.f.degenerate) {
                        p = isl_printer_print_ast_expr(p, node->u.f.init);
                } else {
                        p = isl_printer_print_str(p, "init: ");
                        p = isl_printer_print_ast_expr(p, node->u.f.init);
                        p = isl_printer_print_str(p, ", ");
                        p = isl_printer_print_str(p, "cond: ");
                        p = isl_printer_print_ast_expr(p, node->u.f.cond);
                        p = isl_printer_print_str(p, ", ");
                        p = isl_printer_print_str(p, "inc: ");
                        p = isl_printer_print_ast_expr(p, node->u.f.inc);
                }
                if (node->u.f.body) {
                        p = isl_printer_print_str(p, ", ");
                        p = isl_printer_print_str(p, "body: ");
                        p = isl_printer_print_ast_node(p, node->u.f.body);
                }
                break;
        case isl_ast_node_user:
                p = isl_printer_print_ast_expr(p, node->u.e.expr);
                break;
        case isl_ast_node_if:
                p = isl_printer_print_str(p, "guard: ");
                p = isl_printer_print_ast_expr(p, node->u.i.guard);
                if (node->u.i.then) {
                        p = isl_printer_print_str(p, ", ");
                        p = isl_printer_print_str(p, "then: ");
                        p = isl_printer_print_ast_node(p, node->u.i.then);
                }
                if (node->u.i.else_node) {
                        p = isl_printer_print_str(p, ", ");
                        p = isl_printer_print_str(p, "else: ");
                        p = isl_printer_print_ast_node(p, node->u.i.else_node);
                }
                break;
        case isl_ast_node_block:
                p = isl_printer_print_ast_node_list(p, node->u.b.children);
                break;
        default:
                break;
        }
        p = isl_printer_print_str(p, ")");
        return p;
}

/* Do we need to print a block around the body "node" of a for or if node?
 *
 * If the node is a block, then we need to print a block.
 * Also if the node is a degenerate for then we will print it as
 * an assignment followed by the body of the for loop, so we need a block
 * as well.
 * If the node is an if node with an else, then we print a block
 * to avoid spurious dangling else warnings emitted by some compilers.
 * If the ast_always_print_block option has been set, then we print a block.
 */
static int need_block(__isl_keep isl_ast_node *node)
{
        isl_ctx *ctx;

        if (node->type == isl_ast_node_block)
                return 1;
        if (node->type == isl_ast_node_for && node->u.f.degenerate)
                return 1;
        if (node->type == isl_ast_node_if && node->u.i.else_node)
                return 1;

        ctx = isl_ast_node_get_ctx(node);
        return isl_options_get_ast_always_print_block(ctx);
}

static __isl_give isl_printer *print_ast_node_c(__isl_take isl_printer *p,
        __isl_keep isl_ast_node *node,
        __isl_keep isl_ast_print_options *options, int in_block, int in_list);
static __isl_give isl_printer *print_if_c(__isl_take isl_printer *p,
        __isl_keep isl_ast_node *node,
        __isl_keep isl_ast_print_options *options, int new_line);

/* Print the body "node" of a for or if node.
 * If "else_node" is set, then it is printed as well.
 *
 * We first check if we need to print out a block.
 * We always print out a block if there is an else node to make
 * sure that the else node is matched to the correct if node.
 *
 * If the else node is itself an if, then we print it as
 *
 *      } else if (..)
 *
 * Otherwise the else node is printed as
 *
 *      } else
 *        node
 */
static __isl_give isl_printer *print_body_c(__isl_take isl_printer *p,
        __isl_keep isl_ast_node *node, __isl_keep isl_ast_node *else_node,
        __isl_keep isl_ast_print_options *options)
{
        if (!node)
                return isl_printer_free(p);

        if (!else_node && !need_block(node)) {
                p = isl_printer_end_line(p);
                p = isl_printer_indent(p, 2);
                p = isl_ast_node_print(node, p,
                                        isl_ast_print_options_copy(options));
                p = isl_printer_indent(p, -2);
                return p;
        }

        p = isl_printer_print_str(p, " {");
        p = isl_printer_end_line(p);
        p = isl_printer_indent(p, 2);
        p = print_ast_node_c(p, node, options, 1, 0);
        p = isl_printer_indent(p, -2);
        p = isl_printer_start_line(p);
        p = isl_printer_print_str(p, "}");
        if (else_node) {
                if (else_node->type == isl_ast_node_if) {
                        p = isl_printer_print_str(p, " else ");
                        p = print_if_c(p, else_node, options, 0);
                } else {
                        p = isl_printer_print_str(p, " else");
                        p = print_body_c(p, else_node, NULL, options);
                }
        } else
                p = isl_printer_end_line(p);

        return p;
}

/* Print the start of a compound statement.
 */
static __isl_give isl_printer *start_block(__isl_take isl_printer *p)
{
        p = isl_printer_start_line(p);
        p = isl_printer_print_str(p, "{");
        p = isl_printer_end_line(p);
        p = isl_printer_indent(p, 2);

        return p;
}

/* Print the end of a compound statement.
 */
static __isl_give isl_printer *end_block(__isl_take isl_printer *p)
{
        p = isl_printer_indent(p, -2);
        p = isl_printer_start_line(p);
        p = isl_printer_print_str(p, "}");
        p = isl_printer_end_line(p);

        return p;
}

/* Print the for node "node".
 *
 * If the for node is degenerate, it is printed as
 *
 *      type iterator = init;
 *      body
 *
 * Otherwise, it is printed as
 *
 *      for (type iterator = init; cond; iterator += inc)
 *              body
 *
 * "in_block" is set if we are currently inside a block.
 * "in_list" is set if the current node is not alone in the block.
 * If we are not in a block or if the current not is not alone in the block
 * then we print a block around a degenerate for loop such that the variable
 * declaration will not conflict with any potential other declaration
 * of the same variable.
 */
static __isl_give isl_printer *print_for_c(__isl_take isl_printer *p,
        __isl_keep isl_ast_node *node,
        __isl_keep isl_ast_print_options *options, int in_block, int in_list)
{
        isl_id *id;
        const char *name;
        const char *type;

        type = isl_options_get_ast_iterator_type(isl_printer_get_ctx(p));
        if (!node->u.f.degenerate) {
                id = isl_ast_expr_get_id(node->u.f.iterator);
                name = isl_id_get_name(id);
                isl_id_free(id);
                p = isl_printer_start_line(p);
                p = isl_printer_print_str(p, "for (");
                p = isl_printer_print_str(p, type);
                p = isl_printer_print_str(p, " ");
                p = isl_printer_print_str(p, name);
                p = isl_printer_print_str(p, " = ");
                p = isl_printer_print_ast_expr(p, node->u.f.init);
                p = isl_printer_print_str(p, "; ");
                p = isl_printer_print_ast_expr(p, node->u.f.cond);
                p = isl_printer_print_str(p, "; ");
                p = isl_printer_print_str(p, name);
                p = isl_printer_print_str(p, " += ");
                p = isl_printer_print_ast_expr(p, node->u.f.inc);
                p = isl_printer_print_str(p, ")");
                p = print_body_c(p, node->u.f.body, NULL, options);
        } else {
                id = isl_ast_expr_get_id(node->u.f.iterator);
                name = isl_id_get_name(id);
                isl_id_free(id);
                if (!in_block || in_list)
                        p = start_block(p);
                p = isl_printer_start_line(p);
                p = isl_printer_print_str(p, type);
                p = isl_printer_print_str(p, " ");
                p = isl_printer_print_str(p, name);
                p = isl_printer_print_str(p, " = ");
                p = isl_printer_print_ast_expr(p, node->u.f.init);
                p = isl_printer_print_str(p, ";");
                p = isl_printer_end_line(p);
                p = print_ast_node_c(p, node->u.f.body, options, 1, 0);
                if (!in_block || in_list)
                        p = end_block(p);
        }

        return p;
}

/* Print the if node "node".
 * If "new_line" is set then the if node should be printed on a new line.
 */
static __isl_give isl_printer *print_if_c(__isl_take isl_printer *p,
        __isl_keep isl_ast_node *node,
        __isl_keep isl_ast_print_options *options, int new_line)
{
        if (new_line)
                p = isl_printer_start_line(p);
        p = isl_printer_print_str(p, "if (");
        p = isl_printer_print_ast_expr(p, node->u.i.guard);
        p = isl_printer_print_str(p, ")");
        p = print_body_c(p, node->u.i.then, node->u.i.else_node, options);

        return p;
}

/* Print the "node" to "p".
 *
 * "in_block" is set if we are currently inside a block.
 * If so, we do not print a block around the children of a block node.
 * We do this to avoid an extra block around the body of a degenerate
 * for node.
 *
 * "in_list" is set if the current node is not alone in the block.
 */
static __isl_give isl_printer *print_ast_node_c(__isl_take isl_printer *p,
        __isl_keep isl_ast_node *node,
        __isl_keep isl_ast_print_options *options, int in_block, int in_list)
{
        switch (node->type) {
        case isl_ast_node_for:
                if (options->print_for)
                        return options->print_for(p,
                                        isl_ast_print_options_copy(options),
                                        node, options->print_for_user);
                p = print_for_c(p, node, options, in_block, in_list);
                break;
        case isl_ast_node_if:
                p = print_if_c(p, node, options, 1);
                break;
        case isl_ast_node_block:
                if (!in_block)
                        p = start_block(p);
                p = isl_ast_node_list_print(node->u.b.children, p, options);
                if (!in_block)
                        p = end_block(p);
                break;
        case isl_ast_node_user:
                if (options->print_user)
                        return options->print_user(p,
                                        isl_ast_print_options_copy(options),
                                        node, options->print_user_user);
                p = isl_printer_start_line(p);
                p = isl_printer_print_ast_expr(p, node->u.e.expr);
                p = isl_printer_print_str(p, ";");
                p = isl_printer_end_line(p);
                break;
        case isl_ast_node_error:
                break;
        }
        return p;
}

/* Print the for node "node" to "p".
 */
__isl_give isl_printer *isl_ast_node_for_print(__isl_keep isl_ast_node *node,
        __isl_take isl_printer *p, __isl_take isl_ast_print_options *options)
{
        if (!node || !options)
                goto error;
        if (node->type != isl_ast_node_for)
                isl_die(isl_ast_node_get_ctx(node), isl_error_invalid,
                        "not a for node", goto error);
        p = print_for_c(p, node, options, 0, 0);
        isl_ast_print_options_free(options);
        return p;
error:
        isl_ast_print_options_free(options);
        isl_printer_free(p);
        return NULL;
}

/* Print the if node "node" to "p".
 */
__isl_give isl_printer *isl_ast_node_if_print(__isl_keep isl_ast_node *node,
        __isl_take isl_printer *p, __isl_take isl_ast_print_options *options)
{
        if (!node || !options)
                goto error;
        if (node->type != isl_ast_node_if)
                isl_die(isl_ast_node_get_ctx(node), isl_error_invalid,
                        "not an if node", goto error);
        p = print_if_c(p, node, options, 1);
        isl_ast_print_options_free(options);
        return p;
error:
        isl_ast_print_options_free(options);
        isl_printer_free(p);
        return NULL;
}

/* Print "node" to "p".
 */
__isl_give isl_printer *isl_ast_node_print(__isl_keep isl_ast_node *node,
        __isl_take isl_printer *p, __isl_take isl_ast_print_options *options)
{
        if (!options || !node)
                goto error;
        p = print_ast_node_c(p, node, options, 0, 0);
        isl_ast_print_options_free(options);
        return p;
error:
        isl_ast_print_options_free(options);
        isl_printer_free(p);
        return NULL;
}

/* Print "node" to "p".
 */
__isl_give isl_printer *isl_printer_print_ast_node(__isl_take isl_printer *p,
        __isl_keep isl_ast_node *node)
{
        int format;
        isl_ast_print_options *options;

        if (!p)
                return NULL;

        format = isl_printer_get_output_format(p);
        switch (format) {
        case ISL_FORMAT_ISL:
                p = print_ast_node_isl(p, node);
                break;
        case ISL_FORMAT_C:
                options = isl_ast_print_options_alloc(isl_printer_get_ctx(p));
                p = isl_ast_node_print(node, p, options);
                break;
        default:
                isl_die(isl_printer_get_ctx(p), isl_error_unsupported,
                        "output format not supported for ast_node",
                        return isl_printer_free(p));
        }

        return p;
}

/* Print the list of nodes "list" to "p".
 */
__isl_give isl_printer *isl_ast_node_list_print(
        __isl_keep isl_ast_node_list *list, __isl_take isl_printer *p,
        __isl_keep isl_ast_print_options *options)
{
        int i;

        if (!p || !list || !options)
                return isl_printer_free(p);

        for (i = 0; i < list->n; ++i)
                p = print_ast_node_c(p, list->p[i], options, 1, 1);

        return p;
}

#define ISL_AST_MACRO_FLOORD    (1 << 0)
#define ISL_AST_MACRO_MIN       (1 << 1)
#define ISL_AST_MACRO_MAX       (1 << 2)
#define ISL_AST_MACRO_ALL       (ISL_AST_MACRO_FLOORD | \
                                 ISL_AST_MACRO_MIN | \
                                 ISL_AST_MACRO_MAX)

/* If "expr" contains an isl_ast_op_min, isl_ast_op_max or isl_ast_op_fdiv_q
 * then set the corresponding bit in "macros".
 */
static int ast_expr_required_macros(__isl_keep isl_ast_expr *expr, int macros)
{
        int i;

        if (macros == ISL_AST_MACRO_ALL)
                return macros;

        if (expr->type != isl_ast_expr_op)
                return macros;

        if (expr->u.op.op == isl_ast_op_min)
                macros |= ISL_AST_MACRO_MIN;
        if (expr->u.op.op == isl_ast_op_max)
                macros |= ISL_AST_MACRO_MAX;
        if (expr->u.op.op == isl_ast_op_fdiv_q)
                macros |= ISL_AST_MACRO_FLOORD;

        for (i = 0; i < expr->u.op.n_arg; ++i)
                macros = ast_expr_required_macros(expr->u.op.args[i], macros);

        return macros;
}

static int ast_node_list_required_macros(__isl_keep isl_ast_node_list *list,
        int macros);

/* If "node" contains an isl_ast_op_min, isl_ast_op_max or isl_ast_op_fdiv_q
 * then set the corresponding bit in "macros".
 */
static int ast_node_required_macros(__isl_keep isl_ast_node *node, int macros)
{
        if (macros == ISL_AST_MACRO_ALL)
                return macros;

        switch (node->type) {
        case isl_ast_node_for:
                macros = ast_expr_required_macros(node->u.f.init, macros);
                if (!node->u.f.degenerate) {
                        macros = ast_expr_required_macros(node->u.f.cond,
                                                                macros);
                        macros = ast_expr_required_macros(node->u.f.inc,
                                                                macros);
                }
                macros = ast_node_required_macros(node->u.f.body, macros);
                break;
        case isl_ast_node_if:
                macros = ast_expr_required_macros(node->u.i.guard, macros);
                macros = ast_node_required_macros(node->u.i.then, macros);
                if (node->u.i.else_node)
                        macros = ast_node_required_macros(node->u.i.else_node,
                                                                macros);
                break;
        case isl_ast_node_block:
                macros = ast_node_list_required_macros(node->u.b.children,
                                                        macros);
                break;
        case isl_ast_node_user:
                macros = ast_expr_required_macros(node->u.e.expr, macros);
                break;
        case isl_ast_node_error:
                break;
        }

        return macros;
}

/* If "list" contains an isl_ast_op_min, isl_ast_op_max or isl_ast_op_fdiv_q
 * then set the corresponding bit in "macros".
 */
static int ast_node_list_required_macros(__isl_keep isl_ast_node_list *list,
        int macros)
{
        int i;

        for (i = 0; i < list->n; ++i)
                macros = ast_node_required_macros(list->p[i], macros);

        return macros;
}

/* Print a macro definition for the operator "type".
 */
__isl_give isl_printer *isl_ast_op_type_print_macro(
        enum isl_ast_op_type type, __isl_take isl_printer *p)
{
        switch (type) {
        case isl_ast_op_min:
                p = isl_printer_start_line(p);
                p = isl_printer_print_str(p,
                        "#define min(x,y)    ((x) < (y) ? (x) : (y))");
                p = isl_printer_end_line(p);
                break;
        case isl_ast_op_max:
                p = isl_printer_start_line(p);
                p = isl_printer_print_str(p,
                        "#define max(x,y)    ((x) > (y) ? (x) : (y))");
                p = isl_printer_end_line(p);
                break;
        case isl_ast_op_fdiv_q:
                p = isl_printer_start_line(p);
                p = isl_printer_print_str(p,
                        "#define floord(n,d) "
                        "(((n)<0) ? -((-(n)+(d)-1)/(d)) : (n)/(d))");
                p = isl_printer_end_line(p);
                break;
        default:
                break;
        }

        return p;
}

/* Call "fn" for each type of operation that appears in "node"
 * and that requires a macro definition.
 */
int isl_ast_node_foreach_ast_op_type(__isl_keep isl_ast_node *node,
        int (*fn)(enum isl_ast_op_type type, void *user), void *user)
{
        int macros;

        if (!node)
                return -1;

        macros = ast_node_required_macros(node, 0);

        if (macros & ISL_AST_MACRO_MIN && fn(isl_ast_op_min, user) < 0)
                return -1;
        if (macros & ISL_AST_MACRO_MAX && fn(isl_ast_op_max, user) < 0)
                return -1;
        if (macros & ISL_AST_MACRO_FLOORD && fn(isl_ast_op_fdiv_q, user) < 0)
                return -1;

        return 0;
}

static int ast_op_type_print_macro(enum isl_ast_op_type type, void *user)
{
        isl_printer **p = user;

        *p = isl_ast_op_type_print_macro(type, *p);

        return 0;
}

/* Print macro definitions for all the macros used in the result
 * of printing "node.
 */
__isl_give isl_printer *isl_ast_node_print_macros(
        __isl_keep isl_ast_node *node, __isl_take isl_printer *p)
{
        if (isl_ast_node_foreach_ast_op_type(node,
                                            &ast_op_type_print_macro, &p) < 0)
                return isl_printer_free(p);
        return p;
}