From f637a53e417495c0fcaa4585bb80909bd36a7b3c Mon Sep 17 00:00:00 2001
From: Sven Verdoolaege <skimo@kotnet.org>
Date: Sat, 31 Jan 2015 12:42:14 +0100
Subject: [PATCH] isl_coalesce.c: add_subs: split adding of variables and
 equalities

This will allow us to add additional constraints to the tableau
after the variables have been added but before the equalities
are added in the next commit.

Signed-off-by: Sven Verdoolaege <skimo@kotnet.org>
---
 isl_coalesce.c | 76 +++++++++++++++++++++++++++++++++++++++++++++-------------
 1 file changed, 60 insertions(+), 16 deletions(-)

diff --git a/isl_coalesce.c b/isl_coalesce.c
index f368e2e1..ee1a4f43 100644
--- a/isl_coalesce.c
+++ b/isl_coalesce.c
@@ -2126,31 +2126,49 @@ error:
 }
 
 /* Add variables to "tab" corresponding to the elements in "list"
- * that are not set to NaN.  The value of the added variable
- * is fixed to the purely affine expression defined by the element.
+ * that are not set to NaN.
  * "dim" is the offset in the variables of "tab" where we should
  * start considering the elements in "list".
  * When this function returns, the total number of variables in "tab"
  * is equal to "dim" plus the number of elements in "list".
  */
-static int add_subs(struct isl_tab *tab, __isl_keep isl_aff_list *list, int dim)
+static int add_sub_vars(struct isl_tab *tab, __isl_keep isl_aff_list *list,
+	int dim)
 {
-	int i, extra;
+	int i, n;
+
+	n = isl_aff_list_n_aff(list);
+	for (i = 0; i < n; ++i) {
+		int is_nan;
+		isl_aff *aff;
+
+		aff = isl_aff_list_get_aff(list, i);
+		is_nan = isl_aff_is_nan(aff);
+		isl_aff_free(aff);
+		if (is_nan < 0)
+			return -1;
+
+		if (!is_nan && isl_tab_insert_var(tab, dim + i) < 0)
+			return -1;
+	}
+
+	return 0;
+}
+
+/* For each element in "list" that is not set to NaN, fix the corresponding
+ * variable in "tab" to the purely affine expression defined by the element.
+ * "dim" is the offset in the variables of "tab" where we should
+ * start considering the elements in "list".
+ */
+static int add_sub_equalities(struct isl_tab *tab,
+	__isl_keep isl_aff_list *list, int dim)
+{
+	int i, n;
 	isl_ctx *ctx;
 	isl_vec *sub;
 	isl_aff *aff;
-	int n;
-
-	if (!list)
-		return -1;
 
 	n = isl_aff_list_n_aff(list);
-	extra = n - (tab->n_var - dim);
-
-	if (isl_tab_extend_vars(tab, extra) < 0)
-		return -1;
-	if (isl_tab_extend_cons(tab, 2 * extra) < 0)
-		return -1;
 
 	ctx = isl_tab_get_ctx(tab);
 	sub = isl_vec_alloc(ctx, 1 + dim + n);
@@ -2166,8 +2184,6 @@ static int add_subs(struct isl_tab *tab, __isl_keep isl_aff_list *list, int dim)
 			isl_aff_free(aff);
 			continue;
 		}
-		if (isl_tab_insert_var(tab, dim + i) < 0)
-			goto error;
 		isl_seq_cpy(sub->el, aff->v->el + 1, 1 + dim);
 		isl_int_neg(sub->el[1 + dim + i], aff->v->el[0]);
 		if (isl_tab_add_eq(tab, sub->el) < 0)
@@ -2184,6 +2200,34 @@ error:
 	return -1;
 }
 
+/* Add variables to "tab" corresponding to the elements in "list"
+ * that are not set to NaN.  The value of the added variable
+ * is fixed to the purely affine expression defined by the element.
+ * "dim" is the offset in the variables of "tab" where we should
+ * start considering the elements in "list".
+ * When this function returns, the total number of variables in "tab"
+ * is equal to "dim" plus the number of elements in "list".
+ */
+static int add_subs(struct isl_tab *tab, __isl_keep isl_aff_list *list, int dim)
+{
+	int extra;
+	int n;
+
+	if (!list)
+		return -1;
+
+	n = isl_aff_list_n_aff(list);
+	extra = n - (tab->n_var - dim);
+
+	if (isl_tab_extend_vars(tab, extra) < 0)
+		return -1;
+	if (isl_tab_extend_cons(tab, 2 * extra) < 0)
+		return -1;
+	if (add_sub_vars(tab, list, dim) < 0)
+		return -1;
+	return add_sub_equalities(tab, list, dim);
+}
+
 /* Coalesce basic map "j" into basic map "i" after adding the extra integer
  * divisions in "i" but not in "j" to basic map "j", with values
  * specified by "list".  The total number of elements in "list"
-- 
2.11.4.GIT