X-Git-Url: http://review.tizen.org/git/?a=blobdiff_plain;f=isl_morph.c;h=bd5733dad890c7e380e73455dd6758cdf5ac76ed;hb=747237f4a946ad88d45822eb281dc70665b81a76;hp=0d007e108723cc78e8f902d4a2b457c5003168c0;hpb=6c4507a88b3edfe4b76c6b526c521a5160186aa6;p=platform%2Fupstream%2Fisl.git

diff --git a/isl_morph.c b/isl_morph.c
index 0d007e1..bd5733d 100644
--- a/isl_morph.c
+++ b/isl_morph.c
@@ -172,6 +172,7 @@ __isl_give isl_morph *isl_morph_dom_params(__isl_take isl_morph *morph)
 {
 	unsigned n;
 
+	morph = isl_morph_cow(morph);
 	if (!morph)
 		return NULL;
 	n = isl_basic_set_dim(morph->dom, isl_dim_set);
@@ -192,6 +193,7 @@ __isl_give isl_morph *isl_morph_ran_params(__isl_take isl_morph *morph)
 {
 	unsigned n;
 
+	morph = isl_morph_cow(morph);
 	if (!morph)
 		return NULL;
 	n = isl_basic_set_dim(morph->ran, isl_dim_set);
@@ -314,7 +316,7 @@ error:
 	return NULL;
 }
 
-/* Given a basic set, exploit the equalties in the a basic set to construct
+/* Given a basic set, exploit the equalties in the basic set to construct
  * a morphishm that maps the basic set to a lower-dimensional space.
  * Specifically, the morphism reduces the number of dimensions of type "type".
  *
@@ -782,12 +784,20 @@ __isl_give isl_morph *isl_morph_inverse(__isl_take isl_morph *morph)
 	return morph;
 }
 
+/* We detect all the equalities first to avoid implicit equalties
+ * being discovered during the computations.  In particular,
+ * the compression on the variables could expose additional stride
+ * constraints on the parameters.  This would result in existentially
+ * quantified variables after applying the resulting morph, which
+ * in turn could break invariants of the calling functions.
+ */
 __isl_give isl_morph *isl_basic_set_full_compression(
 	__isl_keep isl_basic_set *bset)
 {
 	isl_morph *morph, *morph2;
 
 	bset = isl_basic_set_copy(bset);
+	bset = isl_basic_set_detect_equalities(bset);
 
 	morph = isl_basic_set_variable_compression(bset, isl_dim_param);
 	bset = isl_morph_basic_set(isl_morph_copy(morph), bset);