From 4e2cbb309f88e1d847d55dbd81d900b22151a866 Mon Sep 17 00:00:00 2001
From: Sven Verdoolaege <skimo@kotnet.org>
Date: Sat, 28 Nov 2009 20:16:03 +0100
Subject: [PATCH] isl_tab_detect_redundant: return status instead of isl_tab *

---
 isl_coalesce.c     |  7 ++++---
 isl_convex_hull.c  |  7 ++++++-
 isl_map_simplify.c |  5 +++--
 isl_tab.c          | 17 +++++++----------
 isl_tab.h          |  2 +-
 5 files changed, 21 insertions(+), 17 deletions(-)

diff --git a/isl_coalesce.c b/isl_coalesce.c
index 0716916f..33399d92 100644
--- a/isl_coalesce.c
+++ b/isl_coalesce.c
@@ -184,8 +184,7 @@ static int fuse(struct isl_map *map, int i, int j, struct isl_tab **tabs,
 		ISL_F_SET(fused, ISL_BASIC_MAP_RATIONAL);
 
 	fused_tab = isl_tab_from_basic_map(fused);
-	fused_tab = isl_tab_detect_redundant(fused_tab);
-	if (!fused_tab)
+	if (isl_tab_detect_redundant(fused_tab) < 0)
 		goto error;
 
 	isl_basic_map_free(map->p[i]);
@@ -196,6 +195,7 @@ static int fuse(struct isl_map *map, int i, int j, struct isl_tab **tabs,
 
 	return 1;
 error:
+	isl_tab_free(fused_tab);
 	isl_basic_map_free(fused);
 	return -1;
 }
@@ -582,7 +582,8 @@ struct isl_map *isl_map_coalesce(struct isl_map *map)
 		if (!ISL_F_ISSET(map->p[i], ISL_BASIC_MAP_NO_IMPLICIT))
 			tabs[i] = isl_tab_detect_implicit_equalities(tabs[i]);
 		if (!ISL_F_ISSET(map->p[i], ISL_BASIC_MAP_NO_REDUNDANT))
-			tabs[i] = isl_tab_detect_redundant(tabs[i]);
+			if (isl_tab_detect_redundant(tabs[i]) < 0)
+				goto error;
 	}
 	for (i = map->n - 1; i >= 0; --i)
 		if (tabs[i]->empty)
diff --git a/isl_convex_hull.c b/isl_convex_hull.c
index d50b0540..c6f28069 100644
--- a/isl_convex_hull.c
+++ b/isl_convex_hull.c
@@ -95,12 +95,17 @@ struct isl_basic_map *isl_basic_map_convex_hull(struct isl_basic_map *bmap)
 
 	tab = isl_tab_from_basic_map(bmap);
 	tab = isl_tab_detect_implicit_equalities(tab);
-	tab = isl_tab_detect_redundant(tab);
+	if (isl_tab_detect_redundant(tab) < 0)
+		goto error;
 	bmap = isl_basic_map_update_from_tab(bmap, tab);
 	isl_tab_free(tab);
 	ISL_F_SET(bmap, ISL_BASIC_MAP_NO_IMPLICIT);
 	ISL_F_SET(bmap, ISL_BASIC_MAP_NO_REDUNDANT);
 	return bmap;
+error:
+	isl_tab_free(tab);
+	isl_basic_map_free(bmap);
+	return NULL;
 }
 
 struct isl_basic_set *isl_basic_set_convex_hull(struct isl_basic_set *bset)
diff --git a/isl_map_simplify.c b/isl_map_simplify.c
index e17dffb9..41fee622 100644
--- a/isl_map_simplify.c
+++ b/isl_map_simplify.c
@@ -1586,9 +1586,10 @@ static struct isl_basic_set *uset_gist(struct isl_basic_set *bset,
 			goto error;
 	bset = isl_basic_set_add_constraints(combined, bset, 0);
 	tab = isl_tab_detect_implicit_equalities(tab);
-	tab = isl_tab_detect_redundant(tab);
-	if (!tab)
+	if (isl_tab_detect_redundant(tab) < 0) {
+		isl_tab_free(tab);
 		goto error2;
+	}
 	for (i = 0; i < context_ineq; ++i) {
 		tab->con[i].is_zero = 0;
 		tab->con[i].is_redundant = 1;
diff --git a/isl_tab.c b/isl_tab.c
index 2583e091..23493e89 100644
--- a/isl_tab.c
+++ b/isl_tab.c
@@ -2421,17 +2421,17 @@ static int con_is_redundant(struct isl_tab *tab, struct isl_tab_var *var)
  * If not, we mark the row as being redundant (assuming it hasn't
  * been detected as being obviously redundant in the mean time).
  */
-struct isl_tab *isl_tab_detect_redundant(struct isl_tab *tab)
+int isl_tab_detect_redundant(struct isl_tab *tab)
 {
 	int i;
 	unsigned n_marked;
 
 	if (!tab)
-		return NULL;
+		return -1;
 	if (tab->empty)
-		return tab;
+		return 0;
 	if (tab->n_redundant == tab->n_row)
-		return tab;
+		return 0;
 
 	n_marked = 0;
 	for (i = tab->n_redundant; i < tab->n_row; ++i) {
@@ -2468,10 +2468,10 @@ struct isl_tab *isl_tab_detect_redundant(struct isl_tab *tab)
 		n_marked--;
 		red = con_is_redundant(tab, var);
 		if (red < 0)
-			goto error;
+			return -1;
 		if (red && !var->is_redundant)
 			if (isl_tab_mark_redundant(tab, var->index) < 0)
-				goto error;
+				return -1;
 		for (i = tab->n_dead; i < tab->n_col; ++i) {
 			var = var_from_col(tab, i);
 			if (!var->marked)
@@ -2483,10 +2483,7 @@ struct isl_tab *isl_tab_detect_redundant(struct isl_tab *tab)
 		}
 	}
 
-	return tab;
-error:
-	isl_tab_free(tab);
-	return NULL;
+	return 0;
 }
 
 int isl_tab_is_equality(struct isl_tab *tab, int con)
diff --git a/isl_tab.h b/isl_tab.h
index 920dea75..bf9ef88f 100644
--- a/isl_tab.h
+++ b/isl_tab.h
@@ -173,7 +173,7 @@ struct isl_basic_map *isl_basic_map_update_from_tab(struct isl_basic_map *bmap,
 struct isl_basic_set *isl_basic_set_update_from_tab(struct isl_basic_set *bset,
 	struct isl_tab *tab);
 struct isl_tab *isl_tab_detect_implicit_equalities(struct isl_tab *tab) WARN_UNUSED;
-struct isl_tab *isl_tab_detect_redundant(struct isl_tab *tab) WARN_UNUSED;
+int isl_tab_detect_redundant(struct isl_tab *tab) WARN_UNUSED;
 #define ISL_TAB_SAVE_DUAL	(1 << 0)
 enum isl_lp_result isl_tab_min(struct isl_tab *tab,
 	isl_int *f, isl_int denom, isl_int *opt, isl_int *opt_denom,
-- 
2.11.4.GIT