From 3769d58bc91ea9900b8c6aa0bf4d8b04596f7abf Mon Sep 17 00:00:00 2001
From: Sven Verdoolaege <skimo@kotnet.org>
Date: Sun, 27 Jun 2010 20:35:29 +0200
Subject: [PATCH 1/1] isl_map_simplify.c: separate out
 isl_basic_map_is_div_constraint

---
 isl_map_private.h  |  2 ++
 isl_map_simplify.c | 59 +++++++++++++++++++++++++++++++++++-------------------
 2 files changed, 40 insertions(+), 21 deletions(-)

diff --git a/isl_map_private.h b/isl_map_private.h
index 95953af..54067c3 100644
--- a/isl_map_private.h
+++ b/isl_map_private.h
@@ -173,3 +173,5 @@ int isl_basic_set_vars_get_sign(__isl_keep isl_basic_set *bset,
 
 int isl_basic_set_add_div_constraints_var(__isl_keep isl_basic_set *bset,
 	unsigned pos, isl_int *div);
+int isl_basic_map_is_div_constraint(__isl_keep isl_basic_map *bmap,
+	isl_int *constraint, unsigned div);
diff --git a/isl_map_simplify.c b/isl_map_simplify.c
index 75a1035..4775efa 100644
--- a/isl_map_simplify.c
+++ b/isl_map_simplify.c
@@ -1105,6 +1105,43 @@ struct isl_basic_set *isl_basic_set_simplify(struct isl_basic_set *bset)
 }
 
 
+int isl_basic_map_is_div_constraint(__isl_keep isl_basic_map *bmap,
+	isl_int *constraint, unsigned div)
+{
+	unsigned pos;
+
+	if (!bmap)
+		return -1;
+
+	pos = 1 + isl_dim_total(bmap->dim) + div;
+
+	if (isl_int_eq(constraint[pos], bmap->div[div][0])) {
+		int neg;
+		isl_int_sub(bmap->div[div][1],
+				bmap->div[div][1], bmap->div[div][0]);
+		isl_int_add_ui(bmap->div[div][1], bmap->div[div][1], 1);
+		neg = isl_seq_is_neg(constraint, bmap->div[div]+1, pos);
+		isl_int_sub_ui(bmap->div[div][1], bmap->div[div][1], 1);
+		isl_int_add(bmap->div[div][1],
+				bmap->div[div][1], bmap->div[div][0]);
+		if (!neg)
+			return 0;
+		if (isl_seq_first_non_zero(constraint+pos+1,
+					    bmap->n_div-div-1) != -1)
+			return 0;
+	} else if (isl_int_abs_eq(constraint[pos], bmap->div[div][0])) {
+		if (!isl_seq_eq(constraint, bmap->div[div]+1, pos))
+			return 0;
+		if (isl_seq_first_non_zero(constraint+pos+1,
+					    bmap->n_div-div-1) != -1)
+			return 0;
+	} else
+		return 0;
+
+	return 1;
+}
+
+
 /* If the only constraints a div d=floor(f/m)
  * appears in are its two defining constraints
  *
@@ -1125,27 +1162,7 @@ static int div_is_redundant(struct isl_basic_map *bmap, int div)
 	for (i = 0; i < bmap->n_ineq; ++i) {
 		if (isl_int_is_zero(bmap->ineq[i][pos]))
 			continue;
-		if (isl_int_eq(bmap->ineq[i][pos], bmap->div[div][0])) {
-			int neg;
-			isl_int_sub(bmap->div[div][1],
-					bmap->div[div][1], bmap->div[div][0]);
-			isl_int_add_ui(bmap->div[div][1], bmap->div[div][1], 1);
-			neg = isl_seq_is_neg(bmap->ineq[i], bmap->div[div]+1, pos);
-			isl_int_sub_ui(bmap->div[div][1], bmap->div[div][1], 1);
-			isl_int_add(bmap->div[div][1],
-					bmap->div[div][1], bmap->div[div][0]);
-			if (!neg)
-				return 0;
-			if (isl_seq_first_non_zero(bmap->ineq[i]+pos+1,
-						    bmap->n_div-div-1) != -1)
-				return 0;
-		} else if (isl_int_abs_eq(bmap->ineq[i][pos], bmap->div[div][0])) {
-			if (!isl_seq_eq(bmap->ineq[i], bmap->div[div]+1, pos))
-				return 0;
-			if (isl_seq_first_non_zero(bmap->ineq[i]+pos+1,
-						    bmap->n_div-div-1) != -1)
-				return 0;
-		} else
+		if (!isl_basic_map_is_div_constraint(bmap, bmap->ineq[i], div))
 			return 0;
 	}
 
-- 
2.7.4