From 7c252d81f541046e7bd5195c91fc092730ad8e18 Mon Sep 17 00:00:00 2001
From: Sven Verdoolaege <skimo@kotnet.org>
Date: Sat, 9 Nov 2013 22:14:31 +0100
Subject: [PATCH] isl_ast_build_expr_from_basic_set: operate on list of
 constraints

That is, instead of iterating over the constraint of the input basic set,
first obtain the list of constraints and then iterate over this list.
Obtaining an explicit list first makes it easier to sort the constraints.

Signed-off-by: Sven Verdoolaege <skimo@kotnet.org>
---
 isl_ast_build_expr.c | 73 ++++++++++++++++++++--------------------------------
 1 file changed, 28 insertions(+), 45 deletions(-)

diff --git a/isl_ast_build_expr.c b/isl_ast_build_expr.c
index 2a8389c1..6848e52f 100644
--- a/isl_ast_build_expr.c
+++ b/isl_ast_build_expr.c
@@ -1112,63 +1112,46 @@ static __isl_give isl_ast_expr *isl_ast_expr_from_constraint(
 	return expr;
 }
 
-struct isl_expr_from_basic_data {
-	isl_ast_build *build;
-	int first;
-	isl_ast_expr *res;
-};
-
-/* Construct an isl_ast_expr that evaluates the condition "c",
- * except if it is a div constraint, and add it to the data->res.
- * The result is simplified in terms of data->build->domain.
- */
-static int expr_from_basic_set(__isl_take isl_constraint *c, void *user)
-{
-	struct isl_expr_from_basic_data *data = user;
-	isl_ast_expr *expr;
-
-	if (isl_constraint_is_div_constraint(c)) {
-		isl_constraint_free(c);
-		return 0;
-	}
-
-	expr = isl_ast_expr_from_constraint(c, data->build);
-	if (data->first)
-		data->res = expr;
-	else
-		data->res = isl_ast_expr_and(data->res, expr);
-
-	data->first = 0;
-
-	if (!data->res)
-		return -1;
-	return 0;
-}
-
 /* Construct an isl_ast_expr that evaluates the conditions defining "bset".
  * The result is simplified in terms of build->domain.
  *
- * We filter out the div constraints during printing, so we do not know
- * in advance how many constraints are going to be printed.
- *
- * If it turns out that there was no constraint, then we contruct
+ * If "bset" is not bounded by any constraint, then we contruct
  * the expression "1", i.e., "true".
+ *
+ * Otherwise, we construct an "and" of the ast expressions of the
+ * individual constraints.
  */
 __isl_give isl_ast_expr *isl_ast_build_expr_from_basic_set(
 	 __isl_keep isl_ast_build *build, __isl_take isl_basic_set *bset)
 {
-	struct isl_expr_from_basic_data data = { build, 1, NULL };
+	int i, n;
+	isl_constraint *c;
+	isl_constraint_list *list;
+	isl_ast_expr *res;
 
-	if (isl_basic_set_foreach_constraint(bset,
-					    &expr_from_basic_set, &data) < 0) {
-		data.res = isl_ast_expr_free(data.res);
-	} else if (data.res == NULL) {
+	list = isl_basic_set_get_constraint_list(bset);
+	isl_basic_set_free(bset);
+	if (!list)
+		return NULL;
+	n = isl_constraint_list_n_constraint(list);
+	if (n == 0) {
 		isl_ctx *ctx = isl_basic_set_get_ctx(bset);
-		data.res = isl_ast_expr_alloc_int_si(ctx, 1);
+		isl_constraint_list_free(list);
+		return isl_ast_expr_alloc_int_si(ctx, 1);
 	}
 
-	isl_basic_set_free(bset);
-	return data.res;
+	c = isl_constraint_list_get_constraint(list, 0);
+	res = isl_ast_expr_from_constraint(c, build);
+	for (i = 1; i < n; ++i) {
+		isl_ast_expr *expr;
+
+		c = isl_constraint_list_get_constraint(list, i);
+		expr = isl_ast_expr_from_constraint(c, build);
+		res = isl_ast_expr_and(res, expr);
+	}
+
+	isl_constraint_list_free(list);
+	return res;
 }
 
 struct isl_expr_from_set_data {
-- 
2.11.4.GIT